U.S. patent application number 09/417464 was filed with the patent office on 2002-01-10 for method and apparatus for representing motion of multiple-jointed object, computer graphic apparatus, and robot controller.
Invention is credited to TAKEUCHI, RYOZO, UNUMA, MUNETOSHI.
Application Number | 20020003540 09/417464 |
Document ID | / |
Family ID | 26456300 |
Filed Date | 2002-01-10 |
United States Patent
Application |
20020003540 |
Kind Code |
A1 |
UNUMA, MUNETOSHI ; et
al. |
January 10, 2002 |
METHOD AND APPARATUS FOR REPRESENTING MOTION OF MULTIPLE-JOINTED
OBJECT, COMPUTER GRAPHIC APPARATUS, AND ROBOT CONTROLLER
Abstract
A bending angle of each joint of a multiple-jointed object is
represented with a function expressed independently of a length
between joints of the object. Based on the function, contour data
is produced for a motion of each joint, which is then displayed on
a screen. With this provision, it is unnecessary to generate again
functions each time the object is changed in its size. Namely, the
functions are independent of the size of the object. Since
parameters of the functions can be altered to add characteristics
to changes in the bending angles the respective joints, the object
is actuated in an action having an emotional expression.
Inventors: |
UNUMA, MUNETOSHI;
(HITACHI-SHI, JP) ; TAKEUCHI, RYOZO; (HITACHI-SHI,
JP) |
Correspondence
Address: |
ANTONELLI TERRY STOUT AND KRAUS
SUITE 1800
1300 NORTH SEVENTEENTH STREET
ARLINGTON
VA
22209
|
Family ID: |
26456300 |
Appl. No.: |
09/417464 |
Filed: |
October 12, 1999 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09417464 |
Oct 12, 1999 |
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08461520 |
Jun 5, 1995 |
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6005589 |
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08461520 |
Jun 5, 1995 |
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08727108 |
Oct 8, 1996 |
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5786788 |
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Current U.S.
Class: |
345/474 |
Current CPC
Class: |
G06T 13/40 20130101;
G01S 13/288 20130101; G01S 7/288 20130101 |
Class at
Publication: |
345/474 |
International
Class: |
G06T 013/00; G06T
015/70 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 12, 1990 |
JP |
02-182632 |
May 23, 1991 |
JP |
03-118341 |
Claims
1. A method of representing a motion of a multiple-jointed object
in which an action of each articulation of the object is controlled
so as to present the motion thereof on a screen, comprising the
steps of: attaining a bending angle of each said joint as a
function independent of a length between joints of the object;
obtaining, based on the functions, data of a contour of the object
in motion in response to an instruction; and displaying the contour
data on the screen.
2. A method of representing a motion of a multiple-jointed object
in which an action of each articulation of the object is controlled
to present the motion thereof on a screen, comprising the steps of:
attaining a bending angle of each said joint as a function of time;
obtaining, based on the functions, data of a contour of the object
in motion in response to an instruction; and displaying the contour
data on the screen.
3. A method according to claim 2 wherein the bending angle of each
said joint is attained as a function of a phase difference, time,
and an amplitude.
4. A method of representing a motion of a multiple-jointed object
in which an action of each articulation of the object is controlled
so as to present the motion thereof on a screen, comprising the
steps of: attaining a bending angle of each said joint as a
function independent of a length between joints of the object;
obtaining, based on the functions, data of a contour of the object
in motion in response to an instruction; displaying the contour
data on a screen, said step of achieving the display on the screen
based the contour data being accomplished by altering values of the
parameters of the functions.
5. A method of representing a motion of a multiple-jointed object
in which an action of each articulation of the object is controlled
to present the motion thereof on a screen, comprising the steps of:
attaining a bending angle of each said joint as a function
independent of a length between joints of the object; specifying in
response to an instruction a feature component to the function, the
component indicating a change in each said joint in motion;
obtaining, based on the functions, data of a contour of the object
in motion in response to an instruction; and displaying the contour
data in association with the feature component on a screen.
6. A method of representing a motion of a multiple-jointed object
in which an action of each articulation of the object is controlled
so as to present the motion thereof on a screen, comprising the
steps of: attaining a bending angle of each said joint as the
following function independent of a length between joints of the
object; 18 m ( t ) = D m + n = 1 A mn sin ( n t + mn - m n ) ( 1 )
D.sub.m: Direct current component A.sub.mn: Amplitude of each
frequency component .PSI..sub.mn: Phase m: Joint number n: Higher
harmonics of order n .PHI..sub.m: Phase difference of 1st order
higher harmonics between reference joint and m-th joint
(.PHI..sub.m=0 for reference joint) obtaining, from the function
(1), data of a contour of the object in motion in response to an
instruction; and displaying the contour data on the screen.
7. A method according to claim 6 further including a step of
changing a value of at least either one of the parameters D.sub.m,
A.sub.mn, and .PSI..sub.mn of the function (1), thereby varying the
motion of the multiple-articulated object acting based on the
function (1).
8. A method according to claim 7, further including the following
steps of: establishing a correspondence between a variation range
of the value of the parameter and the feature component indicating
a change associated with an action of each said joint; and
specifying, in place of the variation range, the feature component,
thereby altering the motion of each said joint.
9. A method according to claim 8 further including a step of
changing a magnitude for the variation range based on the feature
component.
10. A computer graphic apparatus for presenting a motion of a
multiple-hinged object on a screen in which an action of each joint
of the object is controlled so as to present the motion thereof on
the screen, comprising: means for attaining a bending angle of each
said joint as a function independent of a length between joints of
the object; means for obtaining, based on the functions, data of a
contour of the object in motion in response to an instruction; and
means for displaying the contour data on the screen.
11. A computer graphic apparatus for presenting a motion of a
multiple-jointed object on a screen in which an action of each
joint of the object is controlled so as to present the motion
thereof on the screen, comprising; means for attaining a bending
angle of each said joint as a function of time; means for
obtaining, based on the functions, data of a contour of the object
in motion in response to an instruction; and means for displaying
the contour data on the screen.
12. An apparatus according to claim 11 wherein the bending angle of
each said joint is attained as a function of a phase difference,
time, and an amplitude.
13. A computer graphic apparatus for presenting a motion of a
multiple-articulated object on a screen in which an action of each
joint of the object is controlled so as to present the motion
thereof on the screen, comprising; means for attaining a bending
angle of each said joint as a function independent of a length
between joints of the object; means for obtaining, based on the
functions, data of a contour of the object in motion in response to
an instruction; means for displaying the contour data on a screen,
and means for altering values of the parameters of the functions,
thereby changing the display on the screen based on the contour
data.
14. A computer graphic apparatus for presenting a motion of a
multiple-hinged object on a screen in which an action of each joint
of the object is controlled so as to present the motion thereof on
the screen, comprising; means for attaining a bending angle of each
said joint as a function independent of a length between joints of
the object; means for specifying in response to an instruction a
feature component to the functions, the component indicating a
change in each said joint in motion; means for obtaining, based on
the functions, data of a contour of the object in motion in
response to an instruction; and means for displaying the contour
data in association with the feature component on a screen.
15. A computer graphic apparatus for presenting a motion of a
multiple-hinged object on a screen in which an action of each joint
of the object is controlled so as to present the motion thereof on
the screen, comprising; store means for storing therein a bending
angle of each said joint as the following function independent of a
length between joints of the object; 19 m ( t ) = D m + n = 1 A mn
sin ( n t + mn - m n ) ( 1 ) D.sub.m: Direct current component
A.sub.mn: Amplitude of each frequency component .PSI..sub.mn: Phase
m: Joint number n: Higher harmonics of order n .PHI..sub.m: Phase
difference of 1st order higher harmonics between reference joint
and m-th joint (.PHI..sub.m=0 for reference joint) means for
obtaining, based on the function (1), data of a contour of the
object in motion in response to an instruction; and means for
displaying the contour data on the screen.
16. A computer graphic apparatus for presenting a motion of a
multiple-hinged object on a screen in which an action of each joint
of the object is controlled so as to present the motion thereof on
the screen, comprising; store means for storing therein a bending
angle of each said joint as the following function independent of a
length between joints of the object; 20 m ( t ) = ( D m + d m ) + n
= 1 [ ( A mn + a mn ) sin { n t + ( mn + mn ) - mn n } ] ( 2 )
D.sub.m: Direct current component A.sub.mn: Amplitude of each
frequency component .PSI..sub.mn: Phase m: Joint number n: Higher
harmonics of order n .PHI..sub.m: Phase difference of 1st order
higher harmonics between reference joint and m-th joint (.PHI.=0
for reference joint) d.sub.m: Direct current component of
qualification component a.sub.mn: Qualification component of each
frequency component .psi..sub.mn: Phase component of qualification
component means for setting and for changing values of d.sub.mn,
a.sub.mn, and .psi..sub.mn; means for obtaining, based on the
function (2), data of a contour of the object in motion in response
to an instruction; and means for displaying the contour data on the
screen.
17. An apparatus according to claim 16 further including: a table
for storing therein preset/change values respectively of d.sub.m,
a.sub.mn, and .psi..sub.mn of the function (2) and feature
components indicating a change of each said joint in motion with
correspondences established therebetween; and means for referencing
said table based on a specification of the feature components,
thereby determining the preset/change values of d.sub.m, a.sub.mn,
and .psi..sub.mn.
18. A computer graphic apparatus for presenting a motion of a
multiple-hinged object on a screen in which an action of each joint
of the object is controlled so as to present the motion thereof on
the screen, comprising; store means for storing therein a bending
angle of each said joint as the following function independent of a
length between joints of the object; 21 m ( t ) = ( D m + m d m ) +
m _ n = 1 [ ( A mn + m a mn ) sin { n t + ( mn + m mn ) - mn n } ]
( 3 ) D.sub.m: Direct current component A.sub.mn: Aplitude of each
frequency component .PSI..sub.mn: Phase m: Joint number n: Higher
harmonics of order n .PHI..sub.m: Phase difference of 1st order
higher harmonics between reference joint and m-th joint
(.PHI..sub.m=0 for reference joint) d.sub.m: Direct current
component of qualification component a.sub.mn: Qualification
component of each frequency component .psi..sub.mn: Phase component
of qualification component .alpha..sub.m, .beta..sub.m: Magnitude
means for setting and for changing values of the magnitudes
.alpha..sub.m and .beta..sub.m; means for attaining a value of the
function (3) for each said joint; means for obtaining, based on the
function (3), data of a contour of the object in motion in response
to an instruction; and means for displaying the contour data on the
screen.
19. A computer graphic apparatus for presenting a motion of a
multiple-hinged object on a screen in which an action of each joint
of the object is controlled so as to present the motion thereof on
the screen, comprising; store means for storing therein a bending
angle of each said joint as the following function independent of a
length between joints of the object; 22 m ( t ) = ( D m + i m i d m
i ) + m n = 1 [ ( A mn + i m i a mni ) sin { n t + ( mn + i mi mni
) - mn n } ] ( 4 ) D.sub.m: Direct current component A.sub.mn:
Amplitude of each frequency component .PSI..sub.mn: Phase m: Joint
number n: Higher harmonics of order n .PHI..sub.m: Phase difference
of 1st order higher harmonics between reference joint and m-th
joint (.PHI..sub.m=0 for reference joint) d.sub.mi: Direct current
components of respective kinds of qualification components
a.sub.mi: Qualification components of different kinds for each
frequency component .psi..sub.mi: Phase components of respective
kinds of qualification components .alpha..sub.mi: Magnitude of each
qualification component .beta..sub.m: Magnitude of amplitude means
for setting and for changing values of .alpha..sub.mi and
.beta..sub.mi; means for setting and for changing values of
d.sub.mi, a.sub.mni, and .PHI..sub.mni; means for attaining a value
of the function (4) for each said joint; means for obtaining, based
on the function (4), data of a contour of the object in motion in
response to an instruction; and means for displaying the contour
data on the screen.
20. An apparatus according to claim 19 further including: a table
for storing therein preset and change values of d.sub.mi,
a.sub.mni, and .PHI..sub.mni (i varies for each feature component)
of the function (4) and the feature component denoting a change of
each said joint in motion with correspondences established
therebetween; and means for referencing said table depending on a
specification of the feature component, thereby determining the
values of d.sub.mi, a.sub.mni, and .PHI..sub.mni.
21. A robot motion control method in which operational instructions
are supplied to a multiple-articulated robot so as to actuate the
robot in a desired motion, comprising the steps of: attaining a
bending angle of each joint of the robot as a function independent
of a length between joints thereof; obtaining positional data of
each said joint based on the function; creating an operational
instruction for the robot depending on the positional data; and
driving the robot based on the operational instruction.
22. A robot motion control apparatus in which operational
instructions are supplied to a multiple-articulated robot so as to
actuate the robot in a desired motion, comprising: store means for
storing therein a bending angle of each joint of the robot as a
function independent of a length between joints thereof; means for
obtaining positional data of each said joint based on the function;
means for generating an operational instruction for the robot
depending on the positional data; and means for driving the robot
based on the operational instruction.
23. An apparatus for representing a motion of a multiple-jointed
object in which an action of each joint of the object is controlled
so as to present the motion thereof on a screen, comprising: store
means for storing therein a plurality of primary functions of time
designating actions of respective joints of the object; select
means for selecting, from the plural primary functions of time, a
plurality of primary functions of time; computation means for
achieving, based on the selected primary functions of time, a
computation of at least a secondary function of time; and output
means for outputting, based on the secondary function of time, a
motion of the multiple-jointed object.
24. An apparatus according to claim 23 wherein said computation
means achieves, based on a mean value of the selected plural
primary functions of time, the computation of at least a secondary
function of time.
25. An apparatus according to claim 24 wherein the mean value is
obtained by applying magnitudes to the respective primary functions
of time.
26. An apparatus according to claim 23 wherein said output means is
display means.
27. An apparatus for representing a motion of a multiple-jointed
object in which a route of a movement of the object is created,
comprising: input means for inputting therefrom information
designating a first position of the movement of the object,
information denoting at least either one of a speed of the object
and a direction of the movement thereof at the first point,
information indicating a last position of the movement of the
object, and information denoting at least either one of a speed of
the object and a direction of the movement thereof at the last
point; and computation means for achieving computations, based on
the four kinds of information, to attain information designating a
path of the movement of the object from the first position to the
last position.
28. An apparatus according to claim 27 further including display
means for displaying the information designating a path of the
movement of the object from the first position to the last
position.
29. An apparatus according to claim 28 wherein said display means
displays the information designating a first position of the
movement of the object and the information indicating a last
position of the movement of the object.
30. An apparatus according to claim 28 wherein said display means
displays the information denoting at least either one of a speed of
the object and a direction of the movement thereof at the first
point and the information denoting at least either one of a speed
of the object and a direction of the movement thereof at the last
point.
31. An apparatus according to claim 27 wherein the information
denoting at least either one of a speed of the object and a
direction of the movement thereof at the first point and the
information denoting at least either one of a speed of the object
and a direction of the movement thereof at the last point are
vector information.
32. An apparatus for representing a motion of a multiple-jointed
object in which a route of a movement of the object is created,
comprising: input means for inputting therefrom information.
associated with a position of the object in the movement and
information designating a direction of the movement of the object;
and computation means for achieving computations, based on the
information associated with a position of the object in the
movement and the information indicating a direction of the movement
of the object, to attain information designating a path of the
movement of the object being moved.
33. An apparatus according to claim 32 further including store
means for storing therein the information associated with a
position of the object in the movement and the information of a
direction of the movement of the object.
34. An apparatus according to claim 32 wherein the information
denoting a direction of the movement of the object is information
indicating a direction of the object in the movement relative to a
desired point in a coordinate system or to another multiple-jointed
obejct.
35. An apparatus according to claim 32 wherein the information
denoting a direction of the movement of the object is information
indicating a direction of the object in the movement relative to a
desired line in a coordinate system.
36. An apparatus according to claim 32 wherein the information
denoting a direction of the movement of the object is information
indicating a direction of the object in the movement relative to a
desired plane in a coordinate system.
37. An apparatus according to claim 32 wherein the information
denoting a direction of the movement of the object is information
indicating a direction of the object in the movement relative to a
preceding direction of the movement of the object.
38. A motion representing apparatus for representing with functions
of time an action of each joint of a multiple-jointed object,
comprising: means for specifying transit points of the object; path
generate means for generating a path along which the object moves
between specified transit points; and output means for outputting a
motion of the object passing a specified transit point.
39. A motion representing apparatus for representing with functions
of time an action of each joint of a multiple-jointed object
comprising: means for specifying transit points of the object; path
generate means for generating a path along which the object moves
between specified transit points; and output means for outputting a
motion of the object passing a point in the proximity of a
specified transit point.
40. An apparatus according to claim 38 further including means for
drawing a curved line between the specified transit points and for
allowing the object to move along the curved line between the
specified transit points.
41. An apparatus according to claim 38 further including: means for
drawing a curved line between the specified transit points to allow
the object to move along the curved line between the specified
transit points; means operative, when the object moves along the
generated curved line, for minimizing a stride width of a foot of
the object on a side of a radius of curvature and for increasing a
stride width of a foot thereof on a side opposite thereto of a
radius of curvature depending on a radius of curvature of the
curved line where the object is moving; and means for preventing
each said foot from slipping on a tangential plane of the curved
line, thereby controlling the object to move along the curved line
without causing any foot slip.
42. A motion representing apparatus for representing with functions
of time an action of each joint of a multiple-jointed object
comprising: means operative, when the object moves along a curve,
for detecting or computing a radius of curvature of the curve;
means for detecting or computing a speed of the movement of the
object; means for computing a centrifugal force based on the radius
of curvature and the speed; and means for correcting the functions
of time, thereby establishing an equilibrium state between the
centrifugal force and a gravity applied onto the object.
43. An apparatus according to claim 42 further including means for
altering information related to the gravity.
44. A motion representing apparatus for representing with functions
of time an action of each joint of a multiple-jointed object,
comprising: means for specifying a plurality of points in a space;
means for inputting therefrom information related to a number of
steps; and output means for outputting the motion of the object
moving with a specified number of steps between a plurality of
specified number of positions.
45. A motion representing apparatus for representing with functions
of time an action of each joint of a multiple-jointed object,
comprising: means for specifying a plurality of points of time;
means for inputting therefrom information related to a number of
steps; and output means for outputting the motion of the object
moving with a specified number of steps between a plurality of
specified number of points of time.
46. A motion representing apparatus for representing with functions
of time an action of each joint of a multiple-jointed object
comprising, output means for outputting the motion of the object
which takes a specified posture at a specified position during the
movement.
47. A motion representing apparatus for representing with functions
of time an action of each joint of a multiple-jointed object
comprising, output means for outputting the motion of the object
which takes a specified posture at a specified point of time during
the movement.
48. A motion representing apparatus for representing with functions
of time an action of each joint of a multiple-jointed object,
comprising: means for representing with the functions of time the
motion of the object in a specified space; means for achieving an
interpolation on a function of time representing the motion of the
object in a space assigned with a function of time representing a
motion between specified spaces, the interpolation being conducted
by use of a distance between the spaces, thereby generating a
function of time representing the motion of the object at an
intermediate point; and output means for outputting a motion of the
object, the motion changing in a specified interval in
substantially a continuous manner.
49. A motion representing apparatus for representing with functions
of time an action of each joint of a multiple-jointed object,
comprising: means for representing with the functions of time a
motion of the object in a specified point of time; means for
achieving an interpolation on a function of time representing a
motion of the object at a point of time assinged with a function of
time representing a motion between specified points of time, the
interpolation being conducted by use of a period of time between
the points of time, thereby generating a function of time
representing the motion of the object at an intermediate point of
time; and output means for outputting a motion of the object, the
motion changing in a specified interval in substantially a
continuous manner.
50. A motion representing apparatus for representing with functions
of time and by use of a key frame method an action of each joint of
a multiple-jointed object, comprising: means for separating from
the representation of functions of time actions of particular
joints of the object, thereby creating the actions of the separated
joints in the key frame method; and means for combining a
representation of functions of time with a representation obtained
by the key frame method, thereby processing a motion of the
object.
51. An apparatus according to claim 50 further including means for
transforming the motions produced in the key frame method into
functions of time and for memorizing therein the functions of
time.
52. A motion representing apparatus for representing with functions
of time and by use of a key frame method an action of each joint of
a multiple-jointed object, comprising: means for measuring an
action of said each joint of the object; means for transforming the
measured action of said each joint into a function of time; and
output means for outputting a motion of the object depending on the
function of time.
53. An apparatus according to claim 52 wherein said transformation
means corrects the measured action of said each joint of the object
and then transforms the corrected action into a function of
time.
54. A motion representing apparatus for representing with functions
of time an action of each joint of a multiple-jointed object,
wherein actions of respective joints of the object are generated in
a key frame method and then the obtained actions are transformed
into functions of time, thereby outputting a motion of the
object.
55. A motion representing apparatus for representing with functions
of time an action of each joint of a multiple-jointed object,
wherein when a motion of the object is selected, functions of time
are created for all of said joints by use of a group of functions
of time representing an identical action, thereby producing a
motion of the object.
56. A motion representing apparatus for representing with functions
of time an action of each joint of a multiple-jointed object,
wherein when a motion of the object is selected, functions of time
are created for all of said joints by use of a group of functions
of time representing an identical action and/or different actions,
thereby generating a motion of the object.
57. A computer graphic system achieving computer graphics
comprising: a motion representing apparatus according to claim 23;
and a display for displaying the motion of the multiple-articulated
object.
58. A robot control system comprising: a motion representing
apparatus according to claim 23; and a robot being driven in
association with the motion of the object.
59. An apparatus according to claim 23 wherein the primary
functions of time are components of a function of time.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a method of representing a
motion in which a motion of a multiple-articulated object such as a
human or an animal is represented, and in particular, to a motion
representation method, a motion representing apparatus, a computer
graphic apparatus, and a robot controller suitable for facilitating
an operation to set and to change a motion of the multiple-hinged
object when a size thereof is altered and for enabling various
kinds of motions to be represented.
[0002] In order to represent in computer graphics such motions as
walking and running actions of a human and motions of a horse and a
spanworm, a key frame method has been employed in general.
According to the key frame method, to generate motions of a
multiple-articulated object such as a human or a horse, the user
first defines contours thereof at a point of time and at a
subsequent point of time, respectively. Contours between these
periods are determined based on an interpolation so that the
respective contours or shapes thus attained are sequentially
displayed in a time-series manner to resultantly produce a motion
picture in which the multiple-jointed object seems to make a real
action. However, the key frame method is attended with a problem
that the contours thus determined in the time-series manner for the
motion of the object takes a long period of time, which hence
requires a considerably large amount of processing time and which
imposes a heavy load on the operator.
[0003] Heretofore, to overcome this problem, as described in an
article entitled "A Study of Computer Animation Composed of
Animation Primitives by Trigonometric Motion Approximation" written
in the Proceedings of IECE of Japan, January 1980, Vol. J63-D No.
1, an action of a human is shot by a camera to attain an animation
picture thereof on a 16 millimeter (mm) film so as to measure
movements of representative points of joints or articulations. For
each joint portion above, horizontal and vertical positions X and Y
thereof are obtained in centimeters relative to reference positions
in a form of a function of time T, thereby determining a locus of
the movement of each joint portion. Thereafter, the locus of the
movement is approximated by a straight line and a trigonometric
curve such that the computer system achieves computations on the
approxiamted curve to attain respective contour data items in a
time sequence, which are then sequentially displayed as a motion
picture in the graphic system.
[0004] According to the prior art above, the movement of each
articulation thus obtained through the shooting operation on a 16
mm film is analyzed to extract changes in the X-directional and
Y-directional positions relative to the respective reference
positions at each point of time, thereby determining the
approximated curve of the motion of the human. Consequently, a
satisfactory animation picture is developed when the action is to
be expressed by the approximated curve. However, the approxiamted
curve cannot be applied to a case, for example, where the size of
the object is varied or where dimensional ratios between the
respective joints are altered in the motion. In this case, there
arises a problem that the shooting operation is required to be
again actually achieved on the object with the pertinent size
and/or with the associated ratio between the joints, which leads to
a limited degree of freedom for representing the animation. That
is, according to the conventional technology, when generating a
motion picture of a multiple-jointed object in the computer graphic
system, the image can be presented only as an analogy of the real
object thus undergone the shooting operation. This means that
various actions cannot be developed in computer graphics. For
example, only an ordinary walking action of a human shot by the
camera can be displayed in the graphic image. Namely, even when the
ordinary or standard action is modified, a motion picture of, for
example, a violent walking action or a joyful or pleasant walking
motion cannot be obtained. In consequence, heretofore, to express
such an action above, for example, a human model is required to
actually walk with a violent feeling to be shot by a camera so as
to attain an image of the violent walk, which is then analyzed to
implement an objective animation picture. In other words, for
example, when producing a motion picture of animals, insects, and
imaginary objects of which various actions cannot be actually shot
by a camera, various movements thereof cannot be easily presented
in computer graphics.
[0005] In addition, it has been impossible in the conventional
technology to produce an action with a human sentimental feature,
which is usually expressed, for example, by a feature. That is, a
characteristic action with a human emotion cannot be reflected on
animation picture of the multiple-jointed object.
SUMMARY OF THE INVENTION
[0006] It is therefore an object of the present invention to
provide a motion representation method and a computer graphic
apparatus in which even when a size of a multiple-jointed object
and/or a dimensional ratio between joints thereof are altered, a
motion of the object can be easily changed in computer
graphics.
[0007] Another object of the present invention is to provide a
motion representation method and a computer graphic apparatus in
which a multiple-articulated object can achieve various motions
such as those having characteristics of actions of the object in
computer graphics.
[0008] Still another object of the present invention is to provide
a method of and an apparatus for controlling a robot in which an
action of the robot can be determined independent of a size thereof
and in which instructions of various motions can be issued to the
robot, thereby solving a problem, similar to that described above,
appearing when the robot is actually operated for various
actions.
[0009] A first feature of the present invention resides in that in
a case where a motion of a multiple-articulated object is presented
on a display screen by controlling an action of each joint of the
object, a bending angle of each articulation is expressed by a
function independent of a length between articulations such that
data of a contour of the multiple-jointed object in motion are
obtained from the function, thereby displaying an image of the
object according to a change in a size and/or a dimensional ratio
between joints thereof.
[0010] A second feature of the present invention resides suitably
in that in a case where a motion of a multiple-jointed object is
presented on a display screen by controlling an action of each
joint of the object, a bending angle of each articulation is
expressed by the following function independent of a length between
articulations. 1 m ( t ) = D m + n = 1 A mn sin ( n t + mn - m n )
( 1 )
[0011] D.sub.m: Direct-current component
[0012] A.sub.mn: Amplitude of each frequency component
[0013] .PSI..sub.mn: Phase
[0014] m: Joint number
[0015] n: Higher harmonic of n-th order
[0016] .PHI..sub.m: Phase difference of 1st order higher harmonics
between reference joint and m-th joint (.PHI..sub.m=0 for reference
joint)
[0017] Data of a contour of the multiple-jointed object in motion
are obtained from values of the function .theta..sub.m(t) for each
joint.
[0018] A third feature of the present invention resides in that
when a motion of a multiple-jointed object is presented on a
display screen by controlling an action of each joint of the
object, a bending angle of each articulation is expressed by a
function independent of a length between articulations and
components of the respective functions are modified when presenting
the motion of the object.
[0019] A fourth feature of the present invention resides in that in
the function (1), at least either one of the parameter values of
D.sub.m, A.sub.mn, and .PSI..sub.mn is changed.
[0020] A fifth feature of the present invention resides in that in
a robot control operation in which instructions of operations are
supplied to a multiple-jointed robot so as to instruct the robot to
achieve a desired motion, a bending angle of each articulation is
expressed by a function independent of a length between
articulations such that positional data is computed for each joint
of the robot based on the function, thereby producing the
operational instructions.
[0021] A sixth feature of the present invention resides in that a
bending angle of each joint of a multiple-jointed object is
expressed by a function independent of a length between joints so
as to reflect onto the function a feature of a motion such as one
expressed by an element of a human emotion which may be
linguistically represented by a feature.
[0022] A seventh feature of the present invention resides in that
when presenting a motion of a multiple-jointed object on a display
screen by controlling an action of each joint of the object, the
action of the object is expressed by a function of time. Means for
changing parameters disposed to develop various kinds of motions
includes at least either one of means for obtaining a mean value of
parameters of each function of time representing a plurality of
actions, means for controlling a direction or an orientation of the
multiple-jointed object, means for creating a route of a motion,
means for changing a stride length between an inner side and an
outer side of a curve, means for taking into consideration an
influence of a centrifugal force, means for controlling a stride
length in the motion, means for interpolating the function of time
with respect to space, means for combining an action created in the
key frame-method with an action generated from the function of
time, means for producing a function of time from measured data,
means for generating a function of time from the action created in
the key frame method, and means for correcting the function of
time.
[0023] As above, when a bending angle of each articulation of a
multiple-hinged object is expressed by a function, the angle can be
independent of a length between articulations. Consequently, in a
case when a contour of the multiple-jointed object to be displayed
is computed depending on the bending angle of each joint, the
computation can be accomplished independently of the size of the
object, namely, the function need not be prepared again for the
computation. In consequence, even when the multi-articulated object
is changed in its size, the computation of the contour thereof can
be carried out by use of the functions beforehand prepared.
Moreover, to change the representation of the motion, the user need
only modify parameters of the functions to alter, for example, a
change rate of the bending angle of each joint.
[0024] Furthermore, when computing mean values of the respective
parameters of the functions of time representing a plurality of
actions in the motion representation, the motion can be represented
depending on a mean value of a plurality of functions of time.
[0025] The user may control the proceeding direction of the motion
by adjusting the direction of the multiple-articulated object.
[0026] The object can be arbitrarily moved or displaced in a space
based on a route of the motion beforehand prepared.
[0027] The inching width is varied between the inner and outer
sides of a curve and hence the slip of a foot is prevented.
[0028] Owing to the influence of the centrifugal force taken into
consideration, an inclination of a body can be presented in a
circular motion.
[0029] The number of steps in an interval can be controlled
depending on a stride width supervised in a movement.
[0030] Based on an interpolation of a function of time with respect
to a space, the motion can be altered while the object is being
moved. Depending on an interpolation of a function of time with
respect to time, the motion can be varied depending on an elapsed
time.
[0031] By combining a motion produced in the key frame method with
one created from a function of time, there can be represented a
motion which cannot be represented only from the function of
time.
[0032] Measured data are processed to generate a function of time,
which enables an actual motion to be produced depending on the
function of time.
[0033] A function of time is created from a motion obtained in the
key frame method and hence an imaginary action not actually
existing in the accessible environment can be produced from the
function of time.
[0034] A function of time can be corrected by interpolating the
function of time.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] FIG. 1 is a schematic diagram showing the configuration of a
computer graphic apparatus in a first embodiment according to the
present invention;
[0036] FIG. 2 is a diagram showing the display screen layout of the
computer graphic apparatus;
[0037] FIG. 3 is a diagram showing an image of a human in a line
drawing;
[0038] FIG. 4 is a graph presenting measured values of a change in
the bending angles of primary joints of the human;
[0039] FIG. 5 is a graph showing a spectrum related to a curve 3a
of FIG. 4;
[0040] FIG. 6 is a schematic diagram showing the configuration of a
computer graphic apparatus in a second embodiment according to the
present invention;
[0041] FIG. 7A is a graph, identical to the curve 3a of FIG. 4,
presenting the bending angle change of a knee articulation in an
ordinary walking action;
[0042] FIG. 7B is a graph showing the bending angle change of a
knee articulation in a joyful walking action;
[0043] FIG. 8 is a graph showing a spectrum related to the curve of
FIG. 7B;
[0044] FIG. 9 is a graph showing a difference between spectra of
FIGS. 5 and 8, respectively;
[0045] FIG. 10 is a schematic diagram showing the configuration of
a computer graphic apparatus in a third embodiment according to the
present invention;
[0046] FIG. 11 is a schematic diagram showing the configuration of
a computer graphic apparatus in a fourth embodiment according to
the present invention;
[0047] FIG. 12 is a diagram showing the constitution of a control
system of a multiple-jointed object in a fifth embodiment according
to the present invention;
[0048] FIG. 13 is a diagram showing the configuration of a control
system of a multiple-jointed object in a sixth embodiment according
to the present invention;
[0049] FIG. 14 is a diagram showing the constitution of a control
system of a multiple-jointed object in a seventh embodiment
according to the present invention;
[0050] FIG. 15 is a diagram showing the configuration of a control
system of a multiple-jointed object in a eighth embodiment
according to the present invention;
[0051] FIG. 16 is a diagram illustratively showing a relationship
between a transit point and a moving direction;
[0052] FIG. 17 is a diagram showing the configuration of a control
system of a multiple-jointed object in a ninth embodiment according
to the present invention;
[0053] FIG. 18 is a diagram showing relationships between transit
points and a moving direction;
[0054] FIG. 19 is a diagram showing the configuration of a control
system of a multiple-jointed object in a tenth embodiment according
to the present invention;
[0055] FIG. 20 is a diagram showing relationship of strides in a
movement along a curve;
[0056] FIG. 21 is a diagram showing the configuration of a control
system of a multiple-jointed object in an 11th embodiment according
to the present invention;
[0057] FIG. 22 is a diagram schematically showing components of
force applied onto a human in a circular motion;
[0058] FIG. 23 is a diagram showing a correction of a human
posture;
[0059] FIG. 24 is a diagram showing the configuration of a control
system of a multiple-jointed object in a 12th embodiment according
to the present invention;
[0060] FIG. 25 is a diagram showing the configuration of a control
system of a multiple-jointed object in a 13th embodiment according
to the present invention;
[0061] FIG. 26 is a diagram showing a relationship between a moving
route and a stride length;
[0062] FIG. 27 is a diagram showing the constitution of a control
system of a multiple-jointed object in a 14th embodiment according
to the present invention;
[0063] FIG. 28 is a diagram schematically showing relationships
between periods of time and stride lengths;
[0064] FIG. 29 is a diagram showing the configuration of a control
system of a multiple-jointed object in a 15th embodiment according
to the present invention;
[0065] FIG. 30 is a diagram showing the constitution of a control
system of a multiple-jointed object in a 16th embodiment according
to the present invention;
[0066] FIG. 31 is a diagram showing the configuration of a control
system of a multiple-jointed object in a 17th embodiment according
to the present invention;
[0067] FIG. 32 is a diagram illustratively showing an interpolation
of an image during a displacement thereof;
[0068] FIG. 33 is a diagram showing the configuration of a control
system of a multiple-jointed object in an 18th embodiment according
to the present invention;
[0069] FIG. 34 is a diagram showing an interpolation of a motion
with respect to time;
[0070] FIG. 35 is a diagram showing the constitution of a control
system of a multiple-jointed object in a 19th embodiment according
to the present invention;
[0071] FIG. 36 is a diagram showing the configuration of a control
system of a multiple-jointed object in a 20th embodiment according
to the present invention;
[0072] FIG. 37 is a diagram showing the constitution of a system in
which a function of time is created from measured data;
[0073] FIG. 38 is a schematic diagram showing a method of
generating a function of time representing a motion;
[0074] FIG. 39 is a diagram showing another system in which a
function of time is produced from measured data;
[0075] FIG. 40 is a diagram showing still another system in which a
function of time is generated from data measured in the key frame
method;
[0076] FIG. 41 is a diagram showing the configuration of a system
for correcting a data base;
[0077] FIG. 42 is a diagram showing the configuration of a control
system of a multiple-jointed object in a 21st embodiment according
to the present invention;
[0078] FIG. 43 is a diagram showing the operation of an editing
section of the embodiments above in which various parameters are
supplied from a display screen;
[0079] FIG. 44 is a diagram illustratively showing a screen example
employed to specify expressions of a motion;
[0080] FIG. 45 is a diagram showing an example of a screen used to
specify a route and a speed of an action in the motion editor;
[0081] FIG. 46 is a diagram showing a screen example adopted to
correct a motion obtained by the key frame method in the motion
editor;
[0082] FIG. 47 is a block diagram showing the configuration of a
control system of a multiple-jointed object in a 22nd embodiment
according to the present invention; and
[0083] FIG. 48 is a schematic perspective view showing the
constitution of a robot.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0084] Referring now to the drawings, description will be given of
embodiments according to the present invention.
[0085] FIG. 1 shows the configuration of a computer graphic
apparatus in a first embodiment according to the present invention.
In this system, as shown in FIG. 2, an example of a
multiple-jointed object i.e. a human is presented in an animation
picture of a multiple-articulated object 1 on a display screen such
as a CRT. In operation of the computer graphic apparatus, the
multiple-hinged object 1 is represented as a multiple-jointed
object in a linework as shown in FIG. 3. In this line drawing, a
bending angle of each joint (a coxa 2, a knee joint 3, an elbow
joint 4, and a shoulder joint 5 in the example of FIG. 3) is
controlled to attain various kinds of contours. Thereafter, the
body portion is added to the line drawing to display a motion image
of a human (FIG. 2).
[0086] The computer graphic apapratus of FIG. 1 includes a basic
motion function storage 10 for storing therein for each basic
motion a periodic function expressing a bending angle of each
articulation, a basic motion selector 11 for selecting a desired
function from the various functions loaded in the storage 10, a
joint angle computing unit 12 for receiving the function selected
from the storage 10 by the selector 11 and for computing based
thereon a bending angle of the pertinent joint in a time series
manner, a speed controller 13 for controlling a speed at which the
computing unit 12 achieves the computation of the joint angle in a
time series fashion, namely, the speed of a motion conducted by the
joint, a multiple-hinged object contour storage 15 for storing
therein contours used to draw bodies related to lineworks of the
various multiple-jointed objects, a contour selector 16 for
selecting a contour of a multiple-articulated object, a rendering
unit 14 for drawing a body for the motion of the multiple-jointed
object, which is expressed only by joint bending angles computed by
the computing unit 12, based on the contour read from the storage
15, thereby generating image information for displaying the picture
in a two-dimensional manner, and a display 17 for presenting the
picture depending on the image information.
[0087] The basic motion function storage 10 is loaded with
functions associated with a motion of each joint for each basic
action such as a walking action, a running action, or a sitting
action. Under this condition, to select a basic motion, the
operator picks a basic operation specification icon 30 presented on
the display screen as shown in FIG. 2. In the following paragraph,
a walking action of a human image is taken as an example to be
expressed by a function representing a motion to be displayed.
[0088] FIG. 4 is a graph showing curves representing changes with
respect to time of measured bending angles of primary joints of a
walking person viewed from a horizontal direction (X-axis
direction). Curves 2a, 3a, 4a, and 5a designate changes with
respect to time of measured bending angles of the coxa, the knee
joint, the elbow joint, and the shoulder joint, respectively. The
angle changes are measured for two periods (strides or steps).
These curves show correlations existing between the actions of the
respective articulations. FIG. 5 is a spectral diagram obtained by
achieving a Fourier analysis on the measure values 3a of the knee
joint of FIG. 4. Essential spectrum compounds can be expressed by
use of a function of at most degree 5 or 6. Namely, there need not
be employed a complicated expression including high-frequency
components. In consequence, the change .THETA..sub.m(t) with
respect to time of the joint bending angle can be expressed by the
following equation of a quite low degree. For example, as shown in
FIG. 5, seven spectrum elements need only be required to express
the angle change .THETA..sub.m(t). The following function (1) is
identical with the previously described above, but since the
embodiment is clearly described, the function (1) is again used as
follows; 2 m ( t ) = D m + n + 1 A mn sin ( n t + mn - m n ) ( 1
)
[0089] where,
[0090] D.sub.m: Direct current component
[0091] A.sub.mn: Amplitude of each frequency component
[0092] .psi..sub.mn: Phase
[0093] m: Joint number
[0094] n: Higher harmonic of n-th order
[0095] .PHI..sub.n: Phase difference of 1st order higher harmonic
between reference joint and m-th joint (.PHI..sub.m=0 for reference
joint)
[0096] In this connection, the harmonization between the actions of
the respective joints is expressed by use of a difference between
phases of the joints. The phase differences are kept retained
through the motion.
[0097] The joint angle computing unit 12 of FIG. 1 achieves
computations based on the function (1) to obtain an action of the
knee joint while changing the value of the variable t such that the
position of the joint is sequentially displayed at the point of
time t, thereby presenting a motion picture of the knee.
Incidentally, to set the action speed, the operator uses a motion
specification icon 33 of FIG. 2. Namely, when the display item of a
vertical bar 40 in the icon 33 is horizontally shifted by a mouse
cursor or the like, the speed controller 13 of FIG. 1 is activated
to develop its operation. The joint angle computing unit 12
computing based on the function (1) the values of
.THETA..sub.m(t.sub.1), .THETA..sub.m(t.sub.2),
.THETA..sub.m(t.sub.3), etc. in a time series fashion increases the
value of t.sub.2-t.sub.1=t.sub.3-t.sub.2=. . . =.DELTA.t before
achieving the computations when the operator specifies a higher
motion speed.
[0098] Since the function (1) above does not include any parameter
denoting a length, even when a size and/or a dimensional ratio
between joints of the object are/is varied, the function (1) need
not be modified. In consequence, also when it is desired to alter a
size of a multi-hinged object to be displayed, the load imposed on
the operator is not increased; moreover, after the size is changed,
the animation picture of the multi-articulated object can be
displayed at a high speed. That is, according to the embodiment
above, the operator need only select a kind of each basic motion, a
motion speed thereof, and a contour of each joint for a motion
picture. Namely, a motion of a multi-jointed object can be
developed with a quite small amount of information and through a
small number of operation steps.
[0099] Referring now to the motion representing apparatus of FIG.
1, the operation of the first embodiment will be described. First,
the contour storage 15 is loaded, for example, with contour data
related to a state of a person image standing in an upright style
and contour data of a basic posture of a flying butterfly. The
contour selecting unit 16 selects desired contour data therefrom.
For example, when the contour data of a person image are selected,
the selected data are fed to the rendering unit 14. On the other
hand, the basic motion function storage 10 is loaded, for example,
with functions for which parameters of basic actions of a person
such as a walking action, a running action, and a sitting action
are respectively specified. One of the basic motions is selected by
the basic motion selector 11. For example, when a running action is
selected, the function associated with the running action is
transferred to the joint angle computing unit 12, which in turn
achieves a computation of the function (1) to produce data of
angles. The computation result is transferred together with a speed
change rate indicated by the speed controller 13 to the rendering
unit 14. Based on the contour data from the contour storage 15 and
the angle data thus received, the rendering unit 14 creates image
data to be sent to the display 17, which resultantly presents
thereon a picture of the image data.
[0100] FIG. 6 shows the constitution of a computer graphic
apparatus in a second embodiment according to the present
invention. As compared with the configuration of the first
embodiment of FIG. 1, the second embodiment includes a feature
component storage 20 and a feature component selector 21. The joint
angle computing unit 12 is configured to accomplish computations
based on a selected basic operation function and a selected feature
component. The feature component is here associated with a feature
and is used to qualify an action or a motion. That is, the feature
component is a feature such as joyfully, sadly, or delightfully. In
this embodiment, the feature components are expressed in the form
of functions so that the operator specifies a feature component to
be selected. As can be seen from FIG. 2, the operator need only
pick a feature selection icon 31 in the screen to choose a
characteristic component. For example, with the mouse cursor or the
like arranged over the icon 31, each time the left-side button is
actuated features such as "joyfully", "merrily", "like a drunkard",
and "calmly" are sequentially presented. When a desired feature is
displayed on the screen, the operator actuates the right-side
button to select the feature. In a case where "walk" is selected as
the basic motion and "joyfully" is chosen as the feature element,
the object of a human image 1 displayed achieves an indicated
action, namely, the object 1 walks joyfully or merrily. Next, a
description will be given of a control operation of the
characteristic element.
[0101] FIG. 7A is a graph presenting a change with respect to time
of the measured bending angle of a knee joint in an ordinary
walking action, whereas FIG. 7B is a graph showing a change with
respect to time of the measured bending angle of a knee joint in a
joyful walking action (i.e. the person walks joyfully). FIG. 8
shows a result of a spectral analysis achieved on the data of the
joyful walking motion of FIG. 7B. In this connection, a result of a
spectral analysis conducted on the measured values of the ordinary
walking action of FIG. 7A is presented in the graph of FIG. 5.
Consequently, a difference between the spectral analyses denotes
the component associated with the feature "joyfully" as shown in
FIG. 9. Teh graphs of FIGS. 5, 8 and 9 present only the power
spectrum components having respectively different phases. As can be
seen from the spectral graph of FIG. 9, the primary spectrum
representing the expression "joyfully" as a feature element can be
expressed with a function of at most degree 5 or 6. With the
characteristic "joyfully" taking into consideration, the knee
bending angle is represented by a function .THETA..sub.m(t) as
follows. 3 m ( t ) = ( D m + d m ) + n = 1 [ ( A mn + a mn ) sin {
n t + ( mn + mn ) - mn n } ] ( 2 )
[0102] where,
[0103] d.sub.m: Direct-current compound of "joyfully"
[0104] a.sub.mn: Component of "joyfully" in each frequency
component
[0105] .psi.mn: Phase component of "joyfully"
[0106] When the operator selects "joyfully" as the feature
component by means of the selector 21 (FIG. 6), values of d.sub.m,
a.sub.m, and .psi..sub.mn are read from the feature component
storage 20 to be substituted in the function (1), thereby attaining
a function (2) to be fed to the computing unit 12. As a result, the
system displays on the screen an animation picture of a joyfully
walking person.
[0107] In accordance with the second embodiment, only the feature
selection is added to the operations of the first embodiment so
that the multiple-articulated object can conduct an action
qualified by the selected feature.
[0108] Since the operation of the motion representation apparatus
of the second embodiment shown in FIG. 6 can be understood from the
descriptions of the first embodiment of FIG. 1 and the second
embodiment above, a redundant explanation thereof will be here
omitted.
[0109] FIG. 10 shows the configuration of a computer graphic
apparatus in a third embodiment according to the present invention.
When compared with the second embodiment of FIG. 6, this
constitution additionally includes a feature controller 22 and a
feature magnitude designating unit 23. In this embodiment, the
joint angle computing unit 12 achieves computations based on the
following function (3). 4 m ( T ) = ( A m + m d m ) + m n = 1 [ ( A
mn + m a mn ) sin { n t + ( mn + m mn ) - mn n } ] ( 3 )
[0110] where, .alpha..sub.m and .beta..sub.m denote a magnitude of
a feature component and a magnitude or value of an amplitude,
respectively. In this system, the feature magnitude .alpha..sub.m
is changed to specify motions with expressions in a range
including, for example, "walk ordinarily", "walk joyfully", and
"walk quite joyfully". Alternatively, as a feature "sadly" opposite
to "joyfully", there may be specified motions with expressions such
as "quite sadly", "ordinarily", and "quite joyfully". In this
operation, when the display item of the vertical bar 40 is
horizontally shifted in the icon 34 denoting the feature magnitude
of FIG. 2, the feature magnitude designating unit 23 specifies the
desired magnitude of the feature component. The amplitude value
.beta..sub.m is related to a stride length, which takes the larger
value when the indication of the vertical bar 40 approches to the
right end of the icon 32 of FIG. 2. Namely, the multiple-jointed
object walks with a larger stride in the obtained animation
picture.
[0111] According to the third embodiment, only by adding the
magnitude specifying operation to the operations of the second
embodiment, the degree of a feature component and a stride length
can be altered; moreover, the feature magnitude and the stride
length can be changed in a continuous manner.
[0112] FIG. 11 shows the construction of a computer graphic
apparatus in a fourth embodiment according to the present
invention. As compared with the third embodiment in which only one
kind of the feature of an action can be specified, the user can
specify a plurality of features of an action in this embodiment.
For this purpose, there are adopted a feature controller 24 and a
feature magnitude designating unit 25. According to the fourth
embodiment, a walking action may be accomplished with
specifications of, for example, "joyfully" and "slowly". In this
case, the computations are carried out with the following function
(4). It is assumed in this function that the value of each
parameter can be changed. 5 m ( t ) = A mo + i m i d m i ) + m n =
1 [ ( A mn + i m i a m i ) sin { n t + ( mn + i m i mni ) - mn n }
] ( 4 )
[0113] Since a plurality of characteristic components can be
specified for an action, the objective action is conducted with a
wider variety of emotional expressions.
[0114] As above, according to the fourth embodiment, the values of
parameters of the function (4) can be altered in a successive
manner; moreover, the expressions of the action conducted by an
image of a person can be changed depending on the modified
parameters in a realtime manner and through an interactive
operation.
[0115] In the description of the fourth embodiment, the apparatus
controls the functions modified for a motion of a computer graphic
image. However, when a computation result attained from the joint
angle computation unit 12 is employed as an operational instruction
to control an operation of a multiple-articulated robot having a
real size of the pertinent object, there can be implemented a robot
controller operating independently of the size of the robot.
Furthermore, since the actions to be sent as instructions to the
robot can be qualified with the features, the robot can perform
various kinds of actions with desired functions.
[0116] According to the embodiments 1 to 4 described above, since
the contour of a multiple-jointed object and/or a robot at an
intermediate point of a motion can be computed by use of a function
independent of the size thereof, multiple-hinged objects and/or
robots of various sizes can be actuated in a realtime manner. In
addition, the action can be qualified by a feature of the action;
moreover, the degree of the feature can be varied. Consequently,
the motion can be accomplished with quite a large number of
functions.
[0117] Although a human model has been described in conjunction
with the embodiments 1 to 4 above, an effect similar to those of
the embodiments can naturally be developed also for an object such
as a measuring worm.
[0118] Referring next to FIG. 12, a description will be given of a
computer graphic apparatus in a fifth embodiment according to the
present invention. The constitution of FIG. 12 includes a data base
51 for storing therein functions of time for expressions of
motions, a joint angle computing unit 52, a rendering unit 53, a
display 54, and a controller 55. Let us assume here that in order
to actuate a person image, a bending angle of each joint is varied
with respect to time based on the following function. 6 m ( t ) = A
0 + n = 1 l { A n sin ( nt + n ) } ( 5 )
[0119] This function expressing a joint bending angle with respect
to time is obtained from a Fourier series expansion of a period
function in which a letter m denotes a joint number. To represent a
motion of the entire human body, there are required a function
.theta..sub.m(t) for each of the joints. In the function, i stands
for the maximum degree of the series expansion, A.sub.0 designates
a mean value of the bending angle, A.sub.n indicates a spectral
intensity of an n-th order higher harmonic, and .PSI..sub.n
designates a phase of the n-th order higher harmonic.
[0120] The data base 51 is loaded, for each kind of motion, with
coefficients A.sub.0, A.sub.1, . . . , A.sub.i, .PSI..sub.1,
.PSI..sub.2, . . . , and .PSI..sub.i for the function
.theta..sub.m(t) of time associated with each joint of a person
image. The joint angle computing unit 52 computes, based on the
coefficients A.sub.0, A.sub.1, . . . , A.sub.i, .PSI..sub.1,
.PSI..sub.2, . . . , and .PSI..sub.1 of an objective motion, a
bending angle of each human articulation at a point of time. The
rendering unit 53 receives the computated results from the joint
angle computing unit 52 to further compute based thereon a position
and a posture of the person image in a three-dimensional manner so
as to project the attained image data onto a two-dimensional area.
The display 54 presents the resultant picture on its screen. The
controller 55 selects functions of time from the data base 51,
modifies the coefficients A.sub.0, A.sub.1, . . . , A.sub.i,
.PSI..sub.1, .PSI..sub.2, . . . , and .PSI..sub.1 of each selected
function of time .theta..sub.m(t), and controls a variable t of
time.
[0121] As a result, according to the fifth embodiment, a desired
action can be selected, expressions of operations other than those
stored in the data base 51 can be developed, and the action speed
can be controlled depending on the variable t of time.
[0122] FIG. 13 shows the configuration of a computer graphic
apparatus in a sixth embodiment according to the present invention.
This system includes a data base 51 for storing therein functions
of time for expressions of motions, a time function selector 61,
storages 62, 63, and 64 for temporarily storing therein the
selected functions, a mean value computing unit 65 for computing a
mean value of functions of time, a joint angle computing unit 52, a
rendering unit 53, and a display 54. After the function selector 61
choses motions, the components of the functions of time
representing the motions are stored in the temporary storage 62
thereof for each motion. Let us assume here that the number of the
selected motions is j and the amplitudes and phase differences of
the respective functions are as follows. Namely, A.sub.10,
A.sub.11, . . . A.sub.1i, .PSI..sub.11, .PSI..sub.12, . . . ,
.PSI..sub.1i for motion 1; A.sub.20, A.sub.21, . . . A.sub.2i,
.PSI..sub.21, .PSI..sub.22, . . . , .PSI..sub.2i for motion 2; and
A.sub.j0, A.sub.j1, . . . A.sub.ji, .PSI..sub.j1, .PSI..sub.j2, . .
. , .PSI..sub.j1 for motion j. The amplitudes and phases of the
selected functions of time are processed by the function mean value
computing unit 65, which achieves computations thereon to attain a
mean value of each frequency component as follows. 7 A n * = k = 0
j A kn j ( 6 ) n * = k = 1 j kn j ( 7 )
[0123] Using the following function (8), the joint angle computing
unit 52 computes, for each angle of the person image, a bending
angle at a point of time based on the amplitude and the phase
resultant from the functions (6) and (7), respectively. 8 m * ( t )
= A 0 * + n = 1 i { A n * sin ( nt + n * ) } ( 8 )
[0124] The rendering unit 53 processes the data resultant from the
computing unit 52 to obtain information in a three-dimensional
representation of a position and a posture of the person image so
as to project the information onto a two-dimensional space. Based
on the projected result, the display 54 presents a person image on
a screen thereof.
[0125] In short, the system is capable of creating a motion other
than those loaded in the function data base 51 as follows. Namely,
the data base 51 is accessed to obtain therefrom a plurality of
functions of time for expressions of motions such that the
functions are subjected to the computations above, thereby
producing a desired motion.
[0126] FIG. 14 shows the constitution of a computer graphic
apparatus in a seventh embodiment according to the present
invention. This configuration includes a data base 51 for storing
therein functions of time for expressions of motions, a function
selector 61, temporary storages 62 to 64 for temporarily storing
the respective components of the selected functions of time, a unit
71 for computing a weighted mean value of the functions of time, a
joint angle computing unit 52, a rendering unit 53, a display 54,
and a controller 55. For the functions of time representing the
motions thus selected by the function selector 61, the components
thereof are stored in the temporary storage 62 associated therewith
for each motion. It is assumed here that the number of the selected
motions is j and the amplitudes and phase differences of the
respective functions are as follows. That is, A.sub.10, A.sub.11, .
. . A.sub.1i, .PSI..sub.11, .PSI..sub.12, . . . , .PSI..sub.1i for
motion 1; A.sub.20, A.sub.21, . . . A.sub.2i, .PSI..sub.21,
.PSI..sub.22, . . . , .PSI..sub.2i for motion 2; and A.sub.j0,
A.sub.j1, . . . A.sub.j1, .PSI..sub.j1, .PSI..sub.j2, . . . ,
.PSI..sub.ji for motion j. The amplitudes and phases of the
selected functions of time are delivered to the function mean value
computing unit 65, which achieves based thereon computations to
attain a mean value of each frequency component as follows. 9 A n
** = k = 0 j ( A kn k ) j ( 9 ) n ** = k = 1 j ( kn k ) j ( 10
)
[0127] where, .alpha..sub.k denotes a weight of a function of
time.
[0128] According to the following function (11), the joint angle
computing unit 52 computes for each angle of the person a bending
angle at a point of time by use of the amplitude and the phase
attained from the functions (9) and (10), respectively. 10 m ** ( t
) = A 0 ** + n = 1 i { A n ** sin ( nt + n ** ) } ( 11 )
[0129] Thereafter, the rendering unit 53 processes the data
resultant from the computing unit 52 to attain information of a
position and a posture of the person image in a three-dimensional
manner so as to project the information onto a two-dimensional
area. Based on the projected result, the display 54 presents a
human image on a screen thereof.
[0130] As a result of the processing above, the apparatus is
capable of generating a motion other than those loaded in the
function data base 51 as follows. The data base 51 is accessed to
obtain therefrom a plurality of functions of time for expressions
of motions such that based on the functions, the computations above
are executed with the weights for the selected motions taken into
consideration, thereby producing a desired motion.
[0131] FIG. 15 shows the configuration of a computer graphic
apparatus in an eighth embodiment according to the present
invention. This system includes a data base 51 for storing therein
functions of time for expressions of motions, a transit point
specifying unit 81, a moving direction controller 82, a joint angle
computing unit 52, a rendering unit 53, and a display 54. FIG. 16
shows a relationship between a transit point and a moving direction
of a multiple-jointed object 1. It is assumed in this diagram that
a plane defined by the x and y axes is a ground surface where a
human as the multiple-articulated object 1 stands. In this graphic
image, the person stands on the ground in a vertical direction i.e.
along the z-axis. First, the transit point specifying unit 81
designates a transit point 401 of the person in FIG. 16. The moving
direction controller 82 then rotates the object 1 about the y axis
so that the front side thereof faces to the transit point 401. For
the displacement of the object 1, the user selects expressions of
the motion during the movement from the data base 51. Thereafter,
the joint angle computing unit 52 is operated to actuate joints of
the multiple-jointed object 1. Since the object 1 is facing to the
passage point 401 as a result of the operation conducted by the
moving direction controller 82, the object 1 is moved or displaced
toward the transit point 401. The rendering unit 53 processes the
data from the computing unit 52 to generate information of a
position and a posture of the object 1 in a three-dimensional
manner so as to project the information onto a two-dimensional
space. Depending on the projected result, the display 54 presents a
picture of the multiple-articulated object 1 on a screen
thereof.
[0132] With the provision above, the system can control the moving
direction of a human whose motions are represented by the functions
of time.
[0133] FIG. 17 shows the constitution of a computer graphic
apparatus in a ninth embodiment according to the present invention.
This system comprises a data base 51 for storing therein functions
of time for expressions of motions, a transit point specifying unit
81, a moving direction controller 82, a joint angle computing unit
52, a rendering unit 53, and a display 54. FIG. 18 shows an example
of a display screen presenting a relationship between a transit
point and a moving direction of a multiple-jointed object 1. Let us
assume in this diagram that a plane defined by the x and y axes is
a ground surface where the multiple-articulated object 1, namely,
the person stands. In this graphic image, the object 1 takes a
stand posture on the ground in a vertical direction i.e. along the
z-axis of the coordinate system. First, the transit point
specifying unit 81 specifies transit points 601 to 605 of the
object 1 on the plane. The specified transit points are connected
to each other with a curve such as a free curve so as to create a
moving route designated by a position 601 and a curve 606. The
moving direction controller 82 rotates the object 1 about the y
axis so that the front side thereof is oriented to a direction of a
tangent of the curve 606 at a position of the object 1 moving on
the curve 606. For the displacement of the object 1, the user
selects expressions of the motion during the movement from the data
base 51. Based on the selected data, the joint angle computing unit
52 actuates joints of the multiple-jointed object 1. Since the
object 1 is directed along the tangent direction at the current
passage point on the curve 606 as a result of the operation
conducted by the moving direction controller 82, the object 1 is
displaced along the generated curve 606. The rendering unit 53
processes data received from the computing unit 52 to produce
information of a position and a posture of the object 1 in a
three-dimensional manner so as to project the information onto a
two-dimensional space. Based on the projected result, the display
54 presents an image of the object 1 on a screen thereof.
[0134] Through the operation above, the apparatus can arbitrarily
move an image of the human on the plane by controlling the
functions of time representing expressions of motions of the
human.
[0135] There may also utilize still another control method of
controlling the motions of a multiple-hinged object as follows.
Namely, the user supplies the system, from input means (not shown),
with a position 601 denoting a starting point of a movement of the
multiple-articulated object 1, a tangent direction (vector
information) 607 designating at least one of a speed of the object
1 at the starting point of the movement and a direction of the
movement of the object 1 thereat, a position 603 indicating an
ending point of the movement of the object 1, and vector
information (not shown) denoting at least one of a speed of the
object 1 at the ending point of the movement and a direction of the
movement of the object 1 thereat. The inputted information items
are memorized and displayed on the screen. Based on these data
items, the system accomplishes computations to obtain information
denoting a route of the movement of the object 1 from the initial
position 601 to the terminal position 603. Thereafter, the moving
passage portions are similarly computed between the positions 603
and 604, 604 to 605, and 605 to 606 in a sequential manner.
[0136] Moreover, according to a still another motion control
method, the system is supplied with a position 601 related to a
position of the multiple-jointed object 1 in motion and a tangent
direction 607 indicating a direction of the movement of the object
1. The inputted information items are then stored in a memory and
are displayed on a screen. Depending on these data items, the
apparatus conducts computations to attain information designating a
path of the movement of the multiple-articulated object 1. In this
connection, the information item indicating the direction of the
moving object 1 is either one of information denoting a direction
thereof with respect to a desired point in the pertinent coordinate
system or to another multiple-hinged object, information
designating a direction thereof with respect to a desired line in
the pertinent coordinate system, information indicating a direction
thereof with respect to a desired plane in the pertinent coordinate
system, and information denoting a direction thereof with respect
to the current direction of the movement of the object 1.
[0137] FIG. 19 shows the construction of a computer graphic
apparatus in a tenth embodiment according to the present invention.
This system comprises a data base 51 for storing therein functions
of time for expressions of motions, a transit point specifying unit
81, a moving route generator 91, a moving direction controller 82,
a controller 101 for adjusting a stride width in a movement along a
curve, a function correcting unit 102, a joint angle computing unit
52, a rendering unit 53, and a display 54. FIG. 20 shows a
relationship between a stride width of a foot of the object 1 on a
center side of the radius of curvature and a stride width of a foot
on a side opposite thereto of the radius of curvature when the
object 1 as the multiple-jointed object moves along a curve 701.
Let us assume here that a small interval .DELTA.L or 702 at a point
P or 709 on the curve 701 where the object 1 is moving has a center
of curvature 0 or 703 and a radius of curvature R or 704, the
distance between the foot on the center side of the curvature and
the center of curvature 0 is denoted as Ri or by a reference
numeral 705, and the distance between the foot on the side opposite
to the center side of the curvature and the center of curvature 0
is denoted as Ro or by a reference numeral 706. The passage route
or curve 701 of the object 1 is then produced by the transit point
specifying unit 81 and the moving route generator 91 of FIG. 19.
The moving direction controller 82 adjusts the posture of the
object 1 such that the front side thereof is oriented along a
tangent direction at the point P. The stride controller 101
produces, based on the following functions (12) and (13), a stride
length S.sub.i or 707 on the center side of the curvature and a
stride length S.sub.o or 708 on a side opposite thereof when the
multiple-articulated object 1 moves along the curve. In this
connection, a letter S denotes a stride length of the object 1
moving along a straight line. 11 S i = R i R S ( 12 ) S o = R o R S
( 13 )
[0138] For a movement of the object 1, the user accesses the data
base 51 to acquire therefrom functions for desired expressions of
motions to be achieved during the movement of the object 1.
Resultantly, the joint angle computing unit 52 actuates joints of
the object 1. The difference between the strides on the inner and
outer sides is supervised by the stride controller 101 and then the
function correcting unit 102 corrects functions of time
representing the motions. Since the image of the object 1 is
oriented along a tangent direction at the current point of the
passage as a result of the operation achieved by the moving
direction controller 82, the object 1 moves along the curved line
701 without causing any foot slip on the ground. The rendering unit
53 computes, based on the results of the computation of the joint
angle computing unit 52, information of a position and a posture of
the object 1 in the three-dimensional manner so as to project the
information onto a two-dimensional area. The resultant information
is then presented on the display 54.
[0139] With the provisions above, the apparatus can move the human
image whose motions are represented by functions of time freely on
a plane without causing any foot slip on the ground.
[0140] FIG. 21 shows the configuration of a computer graphic
apparatus in an 11th emodiment according to the present invention.
This system comprises a data base 51 for storing therein functions
of time designating expressions of motions, a transit point
specifying unit 81, a moving route generator 91, a moving direction
controller 82, a unit 201 for detecting a radius of curvature, a
moving speed detector 202, a centrifugal force computing unit 203,
a function correcting unit 102, a joint angle computing unit 52, a
rendering unit 53, and a display 54. The moving path of a
multiple-jointed object e.g. a human is created by the transit
point specifying unit 81 and the moving path generator 91. The
moving direction controller 82 adjusts a posture of the person
image such that the front side thereof is oriented along a tangent
direction of a curve of the moving path. FIG. 22 shows a
relationship between forces applied to a person image when the
state of the person image is changed from an upright posture with
respect to the ground surface to a circular motion. This diagram
includes a multiple-hinged object 1, a center of curvature 0, a
radius of curvature R, a gravity force g, a centrifugal force ar,
and a resultant force F of the centrifugal force ar and the gravity
force g. In this state, the object 1 falls down outwardly due to
the centrifugal force ar. More concretely, for the observer, the
object 1 seems to fall down toward the outside. In this situation,
the posture of the object 1 is controlled as follows. In the
system, a radius of curvature of the curve where the object 1 is
just passing is sensed by the detector 201 and the current moving
speed is detected by the moving speed detector 202. Using the
radius of curvature and the moving speed, the centrifugal force
computing unit 203 achieves computations to attain a centrifugal
force ar applied to the object 1. Thereafter, in order arrange the
person posture to be parallel to the resultant force F of the
centrifugal force ar and the gravity g, the function correcting
unit 102 corrects the functions of time representing expressions of
motions to incline the posture of the object 1 by an angle
.theta..sub.f. Resultantly, an equilibrium state is established
between the centrifugal force ar and the gravity force g applied to
the multiple-articulated object 1, which hence does not fall down
onto the ground. Actions of the related joints are then generated
by the joint angle computing unit 52. The rendering unit 53
computes, depending on the results of the computation of the joint
angle computing unit 52, information of a position and a posture of
the object 1 in the three-dimensional manner so as to project the
information onto a two-dimensional area. The display 54 then
presents the obtained information on its screen.
[0141] In short, when moving along a curved line an image of a
person whose motions are represented by functions of time, the
apparatus takes the influence on the centrifugal force into
consideration. Consequently, there can be prevented an unnatural
action in which, for example, the person image seems to fall down
onto the ground.
[0142] FIG. 24 shows the configuration of a computer graphic
apparatus in a 12th embodiment according to the present invention.
This system comprises a data base 51 for storing therein functions
of time representing expressions of motions, a transit point
specifying unit 81, a moving route generator 91, a moving direction
controller 82, a unit 201 for detecting a radius of curvature, a
moving speed detector 202, a gravity correcting unit 301, a
centrifugal force computing unit 203, a function correcting unit
102, a joint angle computing unit 52, a rendering unit 53, and a
display 54. The moving path of a human image is produced by the
transit point specifying unit 81 and the moving route generator 91.
The moving direction controller 82 arranges a posture of the person
image such that the front side thereof is oriented along a tangent
direction of a curve of the moving path. Thereafter, a radius of
curvature of the curve where the object 1 is just moving is
detected by the detector 201 and the current moving speed is sensed
by the moving speed detector 202. Based on the radius of curvature
and the moving speed, the centrifugal force computing unit 203
achieves computations to attain a centrifugal force ar applied to
the person. In order to establish an equilibrium state between the
centrifugal force ar and the gravity force g applied to the
multiple-articulated object, the posture of the person image is
corrected by means of the function correcting unit 102. The gravity
correcting unit 301 is disposed to correct the magnitude of
information associated with the gravity force. When information of
the gravity is varied, for example, when the gravity applied to the
person image is reduced, the posture thereof is greatly inclined;
conversely, when the gravity is increased, the person image becomes
to be stable, thereby presenting actions of the person image in an
arbitrary manner. Thereafter, motions of the related joints are
then generated by the joint angle computing unit 52. The rendering
unit 53 computes, based on the results obtained from the joint
angle computing unit 52, information of a position and a posture of
the person in the three-dimensional fashion so as to project the
information onto a two-dimensional space. The display 54 presents
the resultant information on its screen.
[0143] In short, when moving along a curve an image of a person
whose motions are represented by functions of time, the apparatus
can alter the magnitude of the gravity applied to the person image
such that the change in the posture of the person image passing
along the curved line is represented with an emphasized expression
or a moderate expression.
[0144] FIG. 25 shows the construction of a computer graphic
apparatus in a 13th embodiment according to the present invention.
This constitution includes a data base 51 for storing therein
functions of time representing expressions of motions, a position
specifying unit 501, a distance computing unit 502, a stride
information input device 503, a stride controller 504, a function
correcting unit 102, a joint angle computing unit 52, a rendering
unit 53, and a display 54. FIG. 26 shows a display example of a
relationship between a moving route and a stride of a person image.
This diagram includes a curved line 1001 denoting a moving route of
the person image. The position specifying unit 501 is employed to
specify two points x.sub.1 and x.sub.2 on the curve 1001 and then
the distance computing unit 502 determines a distance L of a
portion x.sub.1x.sub.2 of the curve 1001. The stride input device
503 is disposed to input therefrom a stride count n required when
the person image moves along the curve 1001 from the point x.sub.1
to the point x.sub.2. The stride controller 504 obtains the stride
length S based on the following equation to send the value S to the
function correcting unit 102. 12 S = L n ( 14 )
[0145] The function correcting unit 102 corrests functions of time
chosen from the data base 51 such that the stride width becomes to
be S. Using the corrected functions of time, the joint angle
computing unit 52 generates actions of the respective joints. Based
on the computation results, the rendering unit 53 attains
information of a position and a posture of the person image in the
three-dimension fashion. The information is then projected onto a
two-dimensional space to be presented on a screen by the display
54.
[0146] In summary, the apparatus can move an image of a person
along a preset interval on a curve with a predetermined number of
strides.
[0147] FIG. 27 shows the configuration of a computer graphic
apparatus in a 14th embodiment according to the present invention.
This structure comprises a data base 51 for storing therein
functions of time representing expressions of motions, a time
specifying unit 511, a time computing unit 512, a stride count
input device 503, a controller 514 for supervising a period of time
required for a stride or step, a function correcting unit 102, a
joint angle computing unit 52, a rendering unit 53, and a display
54. FIG. 28 shows a display example of the display 54 representing
a relationship of a stride with respect to time (on a horizontal
line or an abscissa) in a movement of the person image. The time
specifying unit 511 is employed to specify two points of time
t.sub.1 and t.sub.2 on the line 1101 designating elapsed time. The
time computing unit 512 obtains an interval of time between the
points of time t.sub.1 and t.sub.2 on the line 1101. The stride
count input device 503 is disposed to input therefrom a stride
count n required when the person moves during the interval of time
from t.sub.1 to t.sub.2. The stride period controller 514 obtains
the period of T.sub.S required for a step based on the following
equation, thereby sending the attained value T.sub.S to the
function correcting unit 102. 13 T S = T n ( 15 )
[0148] The function correcting unit 102 achieves a correction on
functions of time chosen from the data base 51 such that the stride
period becomes to be T.sub.S. Depending on the corrected functions
of time, the joint angle computing unit 52 generates motions of the
respective joints. On receiving the computation results, the
rendering unit 53 computes based thereon information of a position
and a posture of the person in the three-dimensional fashion. The
information is then projected onto a two-dimensional space so as to
be presented on a screen by the display 54.
[0149] As a result, the system can move an image of a person along
a line during a preset interval of time with a predetermined number
of steps.
[0150] FIG. 29 shows the constition of a computer graphic apparatus
in a 15th embodiment according to the present invention. This
structure comprises a data base 51 for storing therein functions of
time representing expressions of motions, a posture specifying unit
522, a position specifying unit 521, a function correcting unit
102, a joint angle computing unit 52, a rendering unit 53, and a
display 54. The posture specifying unit 522 is adopted to designate
a desired posture (in a stationary state) of a person image. The
position specifying unit 521 is used to denote a position in the
space where the human takes the posture. In this situation, the
person image is moving with motions associated with functions of
time selected from the data base 51. When the person image
approaches the position specified by the position specifying unit
521, in order to develop the posture denoted by the posture
specifying unit 522, the function correcting unit 102 corrects the
functions of time. At the specified position, the person image
takes the denoted posture. Depending on the corrected functions of
time, the joint angle computing unit 52 creates motions of the
respective joints. Based on the computation results, the rendering
unit 53 obtains information of a position and a posture of the
person image in the three-dimensional fashion. The information is
then mapped onto a two-dimensional area to be presented on a screen
by the display 54.
[0151] Resultantly, the constitution can present an image of a
multiple-articulated object in a specified posture at a
predetermined position while the object is acting based on
functions of time.
[0152] FIG. 30 shows the construction of a computer graphic
apparatus in a 16th embodiment according to the present invention.
This structure comprises a data base 51 for storing therein
functions of time representing expressions of motions, a posture
specifying unit 522, a time specifying unit 531, a function
correcting unit 102, a joint angle computing unit 52, a rendering
unit 53, and a display 54. The posture specifying unit 522 is
adopted to designate a desired posture (in a stationary state) of a
person image. The time specifying unit 531 is used to denote a
point of time when the person image takes the posture. The person
image is moving with motions presented by functions of time
selected from the data base 51. At a point of time in the vicinity
of the point of time specified by the time specifying unit 531, in
order to develop the posture designated by the posture specifying
unit 522, the function correcting unit 102 corrects the functions
of time. At the specified point of time, the person image takes the
denoted posture. Using the corrected functions of time, the joint
angle computing unit 52 creates motions of the respective joints.
Based on the computation results, the rendering unit 53 obtains
information of a position and a posture of the person image in the
three-dimensional fashion, which is then projected onto a
two-dimensional area to be displayed on a screen by the display
54.
[0153] With the operations above, the system can present an image
of a multiple-articulated object in a specified posture at a
predetermined point of time while the object is moving based on
functions of time.
[0154] FIG. 31 shows the configuration of a computer graphic
apparatus in a 17th embodiment according to the present invention.
This constitution comprises a data base 51 for storing therein
functions of time representing expressions of motions, a function
selector (A) 542, a position and function storage (A) 545, a
position specifying unit (B) 543, a function selector (B) 544, a
position and function storage (B) 546, a distance computing unit
547, a function interpolating unit 548, a joint angle computing
unit 52, a rendering unit 53, and a display 54. FIG. 32 show a
screen display example of the display 54 useful to explain a method
of interpolating expressions of motions of a person image while the
person image is moving. The person image moves from a left-hand
side to the right-hand side along a straight line 1401. The
position specifying unit (A) 541 is employed to specify a point Xm
or 1402 on the straight line 1401 and then the function selector
(A) 542 is initiated to select from the data base 51 functions of
time related to an expression of the motion at the point 1402. Let
us assume here, that "the person walks in an ordinary manner" has
been selected (1403 in FIG. 32) and that each frequency component
of the function of time has a spectral intensity A.sub.mn and a
phase .PSI..sub.mn. The position X.sub.m on the straight line 1401
and the spectral intensity A.sub.mn and the phase .PSI..sub.mn of
the function of time representing the action are loaded in the
position and function storage (A) 545. Next, the position
specifying unit (B) 543 is used to specify a point X.sub.m+1 or
1404 and then the function selector (B) 544 selects from the data
base 51 functions of time related to an expression of the motion at
the point 1404. It is assumed here that "the person walks
cheerfully" has been selected (1405 in FIG. 32) and that each
frequency component of the function of time has a spectral
intensity A.sub.m+1n and a phase .PSI..sub.m+1n. The specified
position X.sub.m+.sub.1 on the straight line 1401 and the spectral
intensity A.sub.m+1n and the phase .PSI..sub.m+1n of the function
of time representing the motion are stored in the position and
function storage (B) 546. The distance computing unit 547 is
adopted to determine a current position of the person image. Let us
assume here that the current position is denoted as x or by a
reference numeral 1406. The function interpoalting unit 548
processes the functions of time related to the two points and the
current position to obtain a spectral intensity A.sub.n(x) and a
phase .PSI..sub.n(x) of the function of time at the present
position x based on the following equations. 14 A n ( x ) = A mn +
A m + ln - A mn X m + 1 - X m ( x - X m ) ( 16 ) n ( x ) = mn + m +
ln - mn X m + 1 - X m ( x - X m ) ( 17 )
[0155] Using the spectral intensity A.sub.n(x) and a phase
.PSI..sub.n(x) of the function of time determined from the
equations (16) and (17), the joint angle computing unit 52 solves
the following function to attain the joint angles. 15 n ( t ) = A o
( x ) + n = l l { A n ( x ) sin ( nt + n ( x ) ) } ( 18 )
[0156] Based on interporated functions of time, the joint angle
computing unit 52 creates motions of the respective joints. In this
example, there is produced an intermediate action 1403 between the
ordinary walk and the cheerful walk. Based on the computation
results, the rendering unit 53 generates information of a position
and a posture of the person image in the three-dimensional fashion.
The information is then projected onto a two-dimensional space,
which is then presented on a screen by the display 54.
[0157] As a result, the system can present an image of a
multiple-articulated object in which the image moves with an
expression developed by an interpolation of motions between two
specified positions.
[0158] FIG. 33 shows the configuration of a computer graphic
apparatus in an 18th embodiment according to the present invention.
This structure includes a data base 51 for storing therein
functions of time representing expressions of motions, a time
specifying unit (A) 551, a function selector (A) 552, a time and
function storage (A) 555, a time specifying unit (B) 553, a time
and function selector (B) 554, a time and function storage (B) 556,
a time computing unit 557, a function interpolating unit 548, a
joint angle computing unit 52, a rendering unit 53, and a display
54. FIG. 34 shows a screen display example produced by the display
54 for explaining a method of interpolating expressions of motions
of a person image being displaced. In this diagram, a straight line
1501 stands for an axis of time. The time specifying unit (A) 551
is used to specify a point of time T.sub.m or 1502 on the time axis
1501 and then the function selector (A) 552 selects from the data
base 51 functions of time associated with an expression of the
motion at the point of time 1502. Let us assume here, that "the
person walks in an ordinary manner" has been selected (1503 in FIG.
34) and that each frequency component of the function of time has a
spectral intensity A.sub.mn and a phase .PSI..sub.mn. The point of
time T.sub.m specified on the time axis 1501 and the spectral
intensity A.sub.mn and the phase .PSI..sub.mn of the function of
time representing the action are memorized in the time and function
storage (A) 555. Subsequently, the time specifying unit (B) 553 is
adopted to specify a point of time T.sub.m+1 or 1504 and then the
function selector (B) 554 selects from the data base 51 functions
of time related to an expression of the motion at the point of time
1504. Let us assume here that a motion "the person walks
cheerfully" has been chosen (1505 in FIG. 34) and that each
frequency component of the function of time has a spectral
intensity A.sub.m+1 a phase .PSI..sub.m+1n. The specified position
T.sub.m+1 on the time axis 1501 and the spectral intensity
A.sub.m+1n and the phase .PSI..sub.m+1n of the function of time
representing the motion are memorized in the time and function
storage (B) 556. The time computing unit 577 is then activated to
determine a current point of time, which is assumed here to be
denoted as t or by a reference numeral 1506. The function
interpolating unit 558 processes the functions of time associated
with the two points and the current point of time to attain a
spectral intensity A.sub.n(t) and a phase .PSI..sub.n(t) of the
function of time at the present point of time t based on the
following equations. 16 A n ( t ) = A mn + A m + ln - A mn T m + l
- T m ( t - T m ) ( 19 ) n ( t ) = mn + m + ln - mn T m + l - T m (
t - T m ) . ( 20 )
[0159] Using the spectral intensity A.sub.n(t) and the phase
.PSI..sub.n(t) of the function of time determined from the
equations (16) and (17), the joint angle computing unit 52 solves
the following function to obtain the joint angles. 17 n ( t ) = A o
( t ) + n = 1 i { A n ( t ) sin ( nt + n ( t ) ) } ( 21 )
[0160] Based on the functions of time determined through the
interpolation, the joint angle computing unit 52 produces actions
of the respective joints. In this example, there is generated an
intermediate action 1503 between the ordinary walk and the cheerful
walk. Depending on the computation results, the rendering unit 53
generates information of a position and a posture of the person
image in the three-dimensional fashion, which is then projected
onto a two-dimensional space to be displayed on a screen by the
display 54.
[0161] With the provision above, the apparatus can present an image
of a multiple-articulated object in which the image moves with an
interpolated expression developed by an interpolation of motions
between two specified positions.
[0162] FIG. 35 shows the structure of a computer graphic apparatus
in a 19th embodiment according to the present invention. This
configuration includes a data base 51 for storing therein functions
of time representing expressions of motions, an angle specifying
unit 561, a function expression separator 562, a key-frame motion
generator 563, a motion combining unit 564, a joint angle computing
unit 52, a rendering unit 53, and a display 54. In some cases, all
actions of a person image cannot be represented by use of functions
of time stored in the data base 51. For example, in a case where a
motion "a waling person waves his or her hand" is desired to be
produced, even when an action "a person walks" is already loaded in
the data base 51, if a motion of "wave a hand" is missing therein,
the desired action cannot be obtained. Next, a description will be
given of a method of generating a motion, for example, "a walking
person waves his or her hand" in the computer graphic apparatus of
the 19th embodiment. First, functions of time representing an
action "walk" are selected from the data base 51. Let us assume
here that the person image waves the left hand. In this situation,
the joints ranging from the left shoulder joint to the joint of the
tip of the hand are required to be separated from those to be
represented with the functions of time above. This operation is
accomplished by the joint specifying unit 561. The function
expression separator 562 accordingly separates the specified joints
from the function expression. Actions of the remaining joints are
then generated by the joint angle computing unit 52. For the
spearated joints, motions are produced by the key-frame motion
generator 563 creating motions in the key frame method. The motion
combining unit 564 combines the motions generated in the key frame
method with those prepared depending on the functions of time.
Using the combined results, the rendering unit 53 generates
information of a position and a posture of the person image in the
three-dimensional fashion. The information is then projected onto a
two-dimensional space to be presented on a screen by the display
54.
[0163] As a result, the apparatus can present an image of a
multiple-articulated object in which the image conducts an action
not registered to the data base in advance.
[0164] FIG. 36 shows the construction of a computer graphic
apparatus in a 20th embodiment according to the present invention.
This constitution comprises a data base 51 for storing therein
functions of time representing expressions of motions, an angle
specifying unit 561, a function expression separator 562, a
key-frame motion generator 563, a function transformer 571, a
motion combining unit 564, a joint angle computing unit 52, a
rendering unit 53, and a display 54. The structure of this
embodiment is implemented by additionally disposing a function
transformer 571 preceding to the key-frame motion generator 563 of
the apparatus of the 19th embodiment shown in FIG. 35. An action
generated by the key-frame motion generator 563 is transformed by
the function transformer 571 into a function of time such as one
represented by the function (5). The motion represented by the
transformed result is registered to the data base 51 so as to be
used again in another processing later.
[0165] In short, according to the 20th embodiment, a motion which
has not been registered to the data base is generated in the key
frame method and is then transformed into a function of time, which
is registered to the data base so as to be employed again in an
operation later.
[0166] FIG. 37 shows an apparatus for creating a function of time
representing an action. The constitution includes a motion
measuring unit 581, a function transformer 582, and a data base 51
storing functions of time for expressions of motions. FIG. 38 shows
an example of a procedure used to create a function of time
representing an expression of a motion. First, the motion measuring
unit 581 measures an action (angle) of each joint of a person image
as a multiple-articulated object 1. In the example of FIG. 38, a
video camera 1802 is adopted to shoot an image of the object 1 in
motion such that based on an image 1803 presented on a screen for
each frame, the motion of each articulation is measured, which is
obtained, for example, as shown in a graph 1804. The function
transformer 582 then accomplishes a Fourier series expansion on the
measured data to obtain a function (representing an expression of a
motion) similar to the function (5). The resultant function of time
is then loaded in the data base 51.
[0167] Through the operation above, the apparatus can process an
actual action of a person image to create a function of time
representing an expression of the action.
[0168] FIG. 39 shows an apparatus for generating a function of time
representing an expression of a motion. The configuration includes
a motion measuring unit 581, a measured data correcting unit 591, a
function transformer 582, and a data base 51 for storing therein
functions of time for expressions of motions. This system is
materialized by adding the measured data correcting unit 591 to the
apparatus of FIG. 37. The measured data has a difference with
respect to actual data because of a measuring error and an
inappropriate measurement. In order to minimize the discrepancy
therebetween, the measured data correcting unit 591 accomplishes a
filtering operation and a correction on the measured data.
[0169] As a result of these operations, according to the apparatus
of FIG. 39, when an actual motion of a person image is measured,
any error appearing in the measuring operation can be removed to
appropriately create a function of time representing an expression
of the motion.
[0170] FIG. 40 shows a structure of an alternative apparatus for
generating a function of time representing an expression of a
motion. The configuration includes a key-frame motion generator
801, a function transformer 582, and a data base 51 storing
functions of time for expressions of motions. In this system, a
motion of a person image is first generated by the motion generator
801 in the key frame method. The generated motion (a change with
respect to time in the bending angle of each joint) is transformed
into a function of time representing the motion, which is then
registered to the data base 51.
[0171] As a result, the apparatus can produce, based on the motion
prepared according to the key frame method, a function of time
representing an expression of the motion.
[0172] FIG. 41 shows the constitution of a still another apparatus
for creating a function of time representing an expression of a
motion. The configuration includes a data base 51 loaded with
functions of time for expressions of motions and a function
correcting unit 811. In this system, the function correcting unit
811 is disposed to modify a function of time representing the
motion selected from the data base 51. The modifying operation here
includes a filtering operation of a function representing an
action, an interpolation on a motion function, and an operation to
obtain a mean value of a plurality of motion functions. The
modified functions are stored in the data base 51 so as to be used
again in an operation later.
[0173] With this provision, the apparatus of FIG. 41 modifies a
function of time representing the motion selected from the data
base 51 and then stores the modified function in the data base,
thereby enabling the resultant function to be employed again
later.
[0174] FIG. 42 shows a constitution of a computer graphic apparatus
in a 21st embodiment according to the present invention. The
structure of this embodiment includes a data base 51 storing
functions of time for expressions of motions, a function selector
821 for selecting a function of time for a joint constituting a
body of a multiple-articulated object, a temporary storages 822 to
824 for temporarily storing therein selected functions of time for
the associated joints, a function composing unit 825, a joint angle
computing unit 52, a rendering unit 53, and a display 54. The
system of this embodiment is adopted to present an action of a
person image as a multiple-hinged object in which the upper-half
body of the person image conducts a walking action and the
lower-half body thereof achieves a running action. In this example,
the system accomplishes operations as follows. The function
selector 821 selects from the data base 51 functions of time for
the walking action of the upper-half of the body, which are stored
in the temporary storage 822. Subsequently, the function selector
821 similarly selects functions of time for the running action of
the lower-half of the body, which are stored in the temporary
storage 823. The function composing unit 825 then combines the
functions of the upper-half of the body with those of the
lower-half thereof. Based on the resultant function of time, the
joint angle computing unit 52 achieves computations to determine
actions of the respective joints. The rendering unit 53 processes
the resultant data to obtain a position and a posture of the person
image in the three-dimensional fashion. Information of the position
and the posture is then projected onto a two-dimensional space so
as to be displayed on a screen of the display 54.
[0175] Resultantly, according to the 21st embodiment, a function of
time can be selected for each articulation of the person image such
that actions of the respective joints are combined with each other
to achieve a motion of the person image.
[0176] FIG. 43 shows a motion editor 305 available as an editing
section of the configurations of FIGS. 12 to 42. The motion editor
305 is adopted to input various parameters and the like of the
respective emobiment, for example, from a screen. The configuration
of the editor 305 includes a motion expression specifying part 951,
a path and speed specifying part 952, and a key-frame motion
correcting part 953.
[0177] In the screen example of FIG. 44, the motion expression
specifying part 951 is used, for example, to select a function
representing an expression of a motion in the embodiments above and
to adjust weights applied to the selected functions. The motion
expression specifying part 951 outputs a function (related to a
spectral intensity and a phase angle for a motion of each joint)
representing a motion desired by the user.
[0178] FIG. 45 shows a screen display example of the path and speed
specifying part 952 in which a moving path, a moving speed, and an
expression of a motion is specified for an image of a person in the
embodiments above. This part 952 produces data indicating a bending
angle of each joint of the person image for each frame of the
picture.
[0179] In a screen example of the key-frame motion correcting part
953 of FIG. 46, a portion of an expression of a motion represented
by functions of time is separated from the function expressing so
as to be generated according to the key frame method.
[0180] In the embodiments described above, description has been
given of examples in which a computer graphic system is adopted to
represent an image of a person so as to control an action of the
person image. However, the results obtained from the joint angle
computing unit 12 may be used as instructions for actions, namely,
action control signals of a multiple-articulated robot having a
real size of the associated object, thereby implementing a robot
control system driving the robot.
[0181] A description will now be given of such an example. FIG. 47
shows the constitution of an apapratus controlling a robot in a
22nd embodiment according to the present invention. As compared
with the control apparatus of FIG. 1, the object contour storage 15
is dispensed with. Namely, the contour storage 15 is replaced with
a robot 2000 shown in FIG. 48; moreover, the rendering unit 14 is
substituted for actuators A. Each actuator A is disposed to bend an
associated joint of the robot 2000 depending on a joint bending
angle computed by the joint angle computing unit 12. In
consequence, like in the case of the embodiments, the respective
articulations are actuated in a harmonized manner based on a basic
function for an action such as "walk" or "run" selected by the
basic motion selector 11. Moreover, as already described in
conjunction with the embodiments, when the basic motion function
storage 10 is supplied with, in addition to the actions such as
"walk" and "run", feature components, for example, a characteristic
element representing an emotional expression of a person, the robot
2000 can be actuated in a motion such as "walk merrily" or "run
sadly".
* * * * *