U.S. patent application number 10/296179 was filed with the patent office on 2004-02-05 for method for automatically moving on the ground a tool mounted at the end of an articulated arm.
Invention is credited to Riberon, Yves, Robert-Peillard, Jean-Claude.
Application Number | 20040020084 10/296179 |
Document ID | / |
Family ID | 8850682 |
Filed Date | 2004-02-05 |
United States Patent
Application |
20040020084 |
Kind Code |
A1 |
Riberon, Yves ; et
al. |
February 5, 2004 |
Method for automatically moving on the ground a tool mounted at the
end of an articulated arm
Abstract
The invention concerns a method for automatically moving on the
ground a tool mounted at the end of an articulated arm. It consists
in bringing the tool (7, 17, 27) onto a first point of the surface
and in calculating the co-ordinates of said point; in bringing the
tool onto a second point enabling to set a first axis of
co-ordinates of the working plan and to determine the furthermost
point to be reached on said axis; in bringing the tool onto a third
point close to the second co-ordinate axis and enabling to define
the position of the frame of reference of the working plan, then in
a fourth point delimiting the zone plane inside which the work will
be performed and in defining a working plan for the tool capable of
being superimposed with the working surface so as to enable it to
cover, by discontinuous or continuous movements, the entire working
surface.
Inventors: |
Riberon, Yves; (Genas,
FR) ; Robert-Peillard, Jean-Claude; (Communay,
FR) |
Correspondence
Address: |
Oliff & Berridge
PO Box 19928
Alexandria
VA
22320
US
|
Family ID: |
8850682 |
Appl. No.: |
10/296179 |
Filed: |
January 9, 2003 |
PCT Filed: |
May 22, 2001 |
PCT NO: |
PCT/FR01/01584 |
Current U.S.
Class: |
37/447 |
Current CPC
Class: |
F41H 11/18 20130101 |
Class at
Publication: |
37/447 |
International
Class: |
E02F 003/36 |
Foreign Application Data
Date |
Code |
Application Number |
May 26, 2000 |
FR |
00/06794 |
Claims
1. A method for automatically moving over an area of ground, a tool
that is mounted at the end of an articulated arm, characterized in
that it consists in defining and calculating a surface known as the
working surface from several successive touchings of the tool onto
the ground, then in moving the tool (7, 17, 27) over the working
surface.
2. The method as claimed in claim 1, characterized in that it
consists, after defining the working surface, in defining a working
pattern for the tool (7, 17, 27) that can be superposed with the
working surface so as to allow it, through discontinuous or
continuous displacements, to cover the entire working surface.
3. The method as claimed in claim 2, characterized in that it
consists in bringing the tool (7, 17, 27) onto a first point of the
surface and in calculating the coordinates of this point which is
considered to be the point of origin of the working pattern, in
bringing the tool to a second point to orient a first axis of
coordinates of the working pattern and to determine the furthest
point to be reached along this axis, in bringing the tool to a
third point near the second axis of coordinates to define the
position of the frame of reference of the working pattern, then to
a fourth point delimiting the region of the plane within which the
work will be carried out.
4. The method as claimed in one of claims 2 and 3, characterized in
that it consists in defining a working pattern in which the points
reached later by the tool (7, 17, 27) are arranged in two
perpendicular directions in a sequence such that a step
characteristic of the shape of the head of the tool in one
direction is followed by a step characteristic of the size of the
head of the tool in said direction.
5. The method as claimed in one of claims 1 to 4, characterized in
that it consists in controlling the various movements and
displacements of the tool using a computer (10).
6. The method as claimed in claim 5, characterized in that it
consists in supplying the computer (10) with the coordinates of the
four points, from which the computer defines a process of
displacement of the tool over the entire working surface and
controls the members which displace it.
7. The method as claimed in one of claims 5 and 6, characterized in
that during the work on a surface, the computer (10) stores in
memory the various points reached by the tool, and any points of
the surface which might not have been reached, so as to work on
them later.
8. A device for automatically moving over an area of ground, a tool
mounted at the end of an articulated arm, for implementing the
method as claimed in one of claims 1 to 7, characterized in that it
comprises a carrier vehicle (2), on the chassis (3) of which a
turret (5) is mounted to pivot about a vertical axis (A1), this
turret being equipped with an arm (6) consisting of several
elements (6a, 6b, 6c) articulated about horizontal axes (A2, A3,
A4) and at the end of which a tool (7, 17, 27) is mounted, the
turret (5) comprising an angular sensor (C1) determining the angle
it makes with the chassis and each element (6a, 6b, 6c) of the arm
comprising an angular sensor (C2, C3, C4) supplying its inclination
with respect to the horizontal.
9. The device as claimed in claim 8, characterized in that it
comprises a computer (10) equipped with a program for controlling
the displacement of the tool (7, 17, 27) to cover the surface that
is to be made safe, this computer (10) receiving the values
supplied by the various angular sensors (C1, C2, C3, C4) and
delivering at output electrical signals that control electrical
directional control valves (E1, E2, E3, E4) hydraulically powering
the motor (12) that turns the turret (5) and the various rams (13,
14, 15) that actuate the elements of the arm (6a, 6b, 6c) until the
angular values are equal to the calculated values.
Description
[0001] The subject of the present invention is a method for
automatically displacing, over an area of ground, a tool mounted at
the end of an articulated arm, and to a device for implementing
it.
[0002] The articulated arm equipped with the tool may, for example,
be the arm of a motorized shovel, mounted to pivot about a vertical
axis on the chassis of the vehicle.
[0003] When an operator needs, using a tool mounted at the end of
such an arm, to work on a very precise area of ground, he runs into
difficulties in that he manually commands the displacement of the
tool, and is situated a significant distance, of the order of 5 to
6 m, away from the tool and does not always have an accurate view
of the area in which the tool is working. It is therefore not easy,
particularly taking account of the play in the articulation of the
various elements of the arm, to displace the tool over the surface
that is to be worked in such a way as to leave no region of the
ground unworked.
[0004] It is important for work on an area of ground to be very
systematic in certain applications, such as the search for
antipersonnel mines that may be buried in the ground. Making the
ground safe entails leaving no surface unreached by the detection
tool.
[0005] The object of the invention is to provide a method which
allows the working of the ground to be made systematic, so as to
avoid leaving unworked areas.
[0006] To this end, the method for automatically moving over an
area of ground, a tool that is mounted at the end of an articulated
arm, to which it relates, consists in defining and calculating a
surface known as the working surface from several successive
touchings of the tool onto the ground, then in moving the tool over
the working surface.
[0007] Furthermore, this method consists, after defining the
working surface, in defining a working pattern for the tool that
can be superposed with the working surface so as to allow it,
through discontinuous or continuous displacements, to cover the
entire working surface.
[0008] According to one embodiment, this method is characterized in
that it consists in bringing the tool onto a first point of the
surface and in calculating the coordinates of this point which is
considered to be the point of origin of the working pattern, in
bringing the tool to a second point to orient a first axis of
coordinates of the working pattern and to determine the furthest
point to be reached along this axis, in bringing the tool to a
third point near the second axis of coordinates to define the
position of the frame of reference of the working pattern, then to
a fourth point delimiting the region of the plane within which the
work will be carried out.
[0009] According to another feature, this method consists in
defining a working pattern in which the points reached later by the
tool are arranged in two perpendicular directions in a sequence
such that a step characteristic of the shape of the head of the
tool in one direction is followed by a step characteristic of the
size of the head of the tool in said direction.
[0010] Advantageously, the method according to the invention
consists in controlling the various movements and displacements of
the tool using a computer. This allows the operator's task to be
made easier and allows him to reach regions which are not always
directly in his sight.
[0011] In practice, this method consists in supplying the computer
with the coordinates of the four points, from which the computer
defines a process of displacement of the tool over the entire
working surface and controls the members which displace it.
[0012] However, the operator may, at any time, interrupt the
operating and displacement cycle of the tool to control it
manually.
[0013] According to another feature of the invention, during the
work on a surface, the computer stores in memory the various points
reached by the tool, and any points of the surface which might not
have been reaached, so as to work on them later.
[0014] According to another possibility, the operator can select a
working area which is reached directly and automatically
independently of the performing of the working pattern commanded by
the computer.
[0015] A device for implementing this method comprises a carrier
vehicle, on the chassis of which a turret is mounted to pivot about
a vertical axis, this turret being equipped with an arm consisting
of several elements articulated about horizontal axes and at the
end of which a tool is mounted, the turret comprising an angular
sensor determining the angle it makes with the chassis and each
element of the arm comprising an angular sensor supplying its
inclination with respect to the horizontal.
[0016] In a frame of reference attached to the chassis, two axes of
which are situated in a horizontal plane, it is possible to
calculate the coordinates of the end point of the tool with
knowledge, on the one hand, of the distances between the
articulation axes of the various elements of the arm and, on the
other hand, of the angle that each element makes with respect to
the horizontal. The angle formed by the main direction of the tool
with respect to the ground is chosen by the operator, according to
the terrain, and maintained throughout the phase of work. When this
is the case, it is possible to calculate the angles of the turret
with respect to the chassis and of the articulated elements with
respect to the horizontal, with knowledge of the coordinates of the
end point of the tool. Thus, calculated angular values correspond
to each of the points in the space that can be reached by the end
of the tool.
[0017] According to another feature, this device comprises a
computer equipped with a program for controlling the displacement
of the tool to cover the surface that is to be made safe, this
computer receiving the values supplied by the various angular
sensors and delivering at output electrical signals that control
electrical directional control valves hydraulically powering the
motor that turns the turret and the various rams that actuate the
elements of the arm until the angular values are equal to the
calculated values.
[0018] In any event, the invention will be clearly understood with
the aid of the description which follows, with reference to the
appended diagrammatic drawing which, by way of nonlimiting
examples, depicts several embodiments of a device for implementing
this method for working an area of ground:
[0019] FIG. 1 is a perspective view of a device intended to make an
area of ground safe;
[0020] FIG. 2 is a view thereof from above;
[0021] FIG. 3 is a view of a diagram for controlling the tool;
[0022] FIG. 4 is a view of a diagram of the displacement of the
tool over the ground;
[0023] FIG. 5 is a view of a second tool, consisting of a
one-footed vibrating device;
[0024] FIG. 6 is a view of a diagram of the displacement of this
tool over the ground;
[0025] FIG. 7 is a view of the end of the arm of a device, equipped
with a metal detector;
[0026] FIG. 8 is a view of a diagram of the displacement of this
metal detector with respect to the ground.
[0027] FIG. 1 depicts a carrier vehicle 2 comprising a chassis 3
mounted on wheels and able to be stabilized horizontally by
stabilizing rams 4. Mounted on the chassis 3 is a turret 5 which
can pivot about a vertical axis A. The turret comprising an angular
sensor C1 which makes it possible to determine the angle formed by
the turret with respect to the chassis. Articulated about a
horizontal axis A2 to the turret is an arm 6 consisting of three
elements 6a, 6b and 6c, the element 6b being articulated to the
element 6a about a horizontal axis A3 and the element 6c being
articulated to the end of the element 6b about an axis A4. The
elements 6a, 6b and 6c are equipped respectively with angular
sensors C2, C3 and C4 to determine the angle that each element
makes with the horizontal.
[0028] Fixed to the end of the element 6c is the tool 7 which
comprises parallel rods 8 each equipped, at its lower end, with a
foot 9 for resting on the ground. The tool 7 is also equipped with
a device for vibrating the rods 8 and the feet 9, which device is
known per se and not depicted.
[0029] In a frame of reference attached to the chassis, two of the
axes, X and Y, of which are placed in a horizontal plane, it is
possible to calculate the coordinates of the end point of the tool
with knowledge, on the one hand, of the lengths of the various
elements 6a, 6b, 6c and of the angles at the axes A1, A2, A3 and
A4. In the embodiment depicted in the drawing, the vertical axis
corresponding to the axis of rotation of the turret is defined by
the reference Z.
[0030] As shown in FIG. 3, the device according to the invention is
equipped with a computer 10 receiving the signals representing the
angular values of the sensors C1, C2, C3 and C4. At output, the
computer delivers electrical signals controlling electrical
directional control valves E1, E2, E3 and E4 powering the motor 12
that turns the turret 5, and rams 13, 14 and 15 that drive the
respective elements 6a, 6b and 6c, respectively.
[0031] In practice, the operator displaces the tool until he makes
the end point of the tool coincide with a point he has chosen on
the surface of the ground that is it to be worked. Using the
angular values measured in this position, the coordinates of the
point are calculated in the origin frame of reference of the
machine and stored in memory. This operation is carried out four
times in succession. The first point thus determined is the point
of origin of the working pattern. The second point orients the
first axis of coordinates of the working pattern and determines the
maximum point to be reached along this axis. The third point
determined, and close to the second axis of coordinates, makes it
possible to define the position of the frame of reference of the
working pattern, and the fourth point delimits the area of the
plane within which the making-safe work will be performed.
[0032] It is understandable that all the coordinates of the points
of the working pattern are known and therefore that all the points
of the pattern situated inside the determined working region can be
reached in succession by the tool.
[0033] By way of example, the computer will, from software using
parameters such as the number of feet, the size of the feet in two
rectangular directions and the space in between two feet, control a
working pattern.
[0034] In the example depicted schematically in FIG. 4, the feet
are square and there are six of them. The six feet are placed in a
corner of the working surface by a command from the computer. This
is the position centered on the point 0. Once the feet have been
vibrated, they are displaced along the X-axis by a first step P1
corresponding to half the dimension of one foot. The feet occupy
the position, defined in chain line, and the feet are centered on
the point 1. In this second position, the feet cover the spaces
which were delimited between the feet, in the position 0, which
spaces were oriented parallel to the Y-axis. All the feet are then
displaced by a step P2, still along the X-axis, by a value equal to
2.5 times the size of all of the feet in the X-direction. The feet
are centered on the point 2. After vibrating, they are displaced by
the value of the first step P1, that is to say half the size of one
foot, to bring them into position 3 and so on along the X-axis. The
same procedure is followed along the Y-axis, it thus being possible
for the entire surface to be covered, without leaving any region
unexplored, by successive displacements with two different step
sizes.
[0035] This displacement is preferably automated and controlled by
the computer, as mentioned earlier. The computer stores in memory
those regions which have been reached by the tool, and possibly
regions which might not have been reached, particularly as a result
of the displacement of the tool perhaps not being perfectly linear
in both directions, given the rotation of the turret. In order to
obtain perfect linearity of the displacement of the tool in both
directions it would be possible to envision the tool having an
additional degree of freedom, allowing it to rotate about a
vertical axis about the element 6c, in order to keep it perfectly
parallel to itself as the turret turns on the chassis.
[0036] FIG. 5 depicts a second device, of which only the end of the
arm is depicted in the drawing, and which differs from the previous
device in the form of the tool. In this second device, the same
elements are denoted by the same references as previously. In this
device, the tool 17, also intended for making the ground safe,
comprises one foot 19 mounted at the end of a bar 18. This foot 19,
having been rested on the ground, can be set in vibration in a way
known per se. FIG. 6 shows the working pattern for the tool on the
ground. In this case also, the computer defines, in the two
directions X and Y, points on which the tool must come to rest in
succession as it is displaced over the ground. Given that there is
only one foot, in this instance, the step with which the foot is
displaced both in the X and Y directions, corresponds to a length
shorter than the dimension of the foot in the direction considered.
It may be noted that, in FIG. 6, a slight pivoting of the foot is
depicted to take account of the rotation of the turret on which the
arm is mounted. However, the computer modifies the angular position
of the arm so that in spite of the pivoting of the turret, the
points defined by the working pattern remain aligned.
[0037] FIG. 7 depicts a device in which the same elements are
denoted by the same references as previously. In this device, a
tool 27 is equipped with a metal detector 29 borne by a bar 28. As
shown in the drawing, the lower end of the bar 28 protrudes from
the metal detector to allow it to rest on the ground, particularly
to delimit the working plane.
[0038] As shown in FIG. 8, for determining the working pattern, the
surface taking into consideration is the square 30 inscribed inside
the circular detector 29. The displacement of the detector occurs
with a step, in either one of the two directions X or Y, which is
shorter than the dimension of the side of the square 30, so that
there is a region of overlap between one position and the next.
While the detector can be displaced stepwise, it is also possible
to perform continuous displacement, especially if the metal
detector does not rest on the ground but follows the surface
thereof from a distance.
[0039] As is evident from the foregoing, the invention provides a
vast improvement to the existing art by allowing automation of the
area of ground using a tool, making the working of this entire area
systematic.
[0040] As goes without saying, the tool could be other than those
described above, without thereby departing from the scope of the
invention.
* * * * *