U.S. patent number RE39,834 [Application Number 10/430,727] was granted by the patent office on 2007-09-11 for apparatus and method for three-dimensional contouring.
This patent grant is currently assigned to Michigan Technological University, Somero Enterprises, Inc.. Invention is credited to Charles A. Hallstrom, Carl B. Kieranen, Nils P. Ruonavaara, Glen R. Simula, James D. Waineo.
United States Patent |
RE39,834 |
Kieranen , et al. |
September 11, 2007 |
**Please see images for:
( Certificate of Correction ) ** |
Apparatus and method for three-dimensional contouring
Abstract
A contouring device and method for contouring
three-dimensionally curved surfaces includes an elongated
contouring assembly that is supported at opposite ends by a pair of
fluid cylinders. The fluid cylinders are controlled to raise and
lower the ends of the contouring assembly independently of each
other, thereby allowing the contouring assembly to create a
three-dimensionally curved surface as it passes over an area to be
contoured. The control of one of the fluid cylinders is based on a
comparison of the measured position of a first end of the
contouring assembly with a profile of the surface to be leveled
that is stored in a computer memory. The measurement of the
position of the first end of the contouring assembly is achieved by
a tracking device which tracks the position of a target positioned
on the first end of the contouring assembly and which determines
the three dimensional position of the target. A proximity sensor
measures the position of the second end of the contouring assembly
from a surface and outputs a control signal that adjusts the height
of the second end of the contouring assembly to follow the surface.
Alternatively, a second target positioned on the second contouring
assembly end is tracked by a second tracking device to determine
the three-dimensional position of the second end. The contouring
assembly preferably has a plow, rotating auger, and a vibratory
screed positioned adjacent and parallel to one another in an
orientation transverse to the direction of motion of the contouring
assembly. The plow, rotating auger, and vibratory screed are all
pivotable about an axis parallel to their longitudinal direction. A
pivot or tilting controller controls the tilting of the plow,
rotating auger, and vibratory screed to follow the slope of the
profile stored in computer memory.
Inventors: |
Kieranen; Carl B. (Chassell,
MI), Hallstrom; Charles A. (Calumet, MI), Simula; Glen
R. (Hancock, MI), Ruonavaara; Nils P. (Atlantic Mine,
MI), Waineo; James D. (Chassell, MI) |
Assignee: |
Michigan Technological
University (Houghton, MI)
Somero Enterprises, Inc. (Jaffrey, NH)
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Family
ID: |
22657416 |
Appl.
No.: |
10/430,727 |
Filed: |
May 6, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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Reissue of: |
09179648 |
Oct 27, 1998 |
06227761 |
May 8, 2001 |
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Current U.S.
Class: |
404/84.5;
404/118; 404/120; 404/83; 404/84.05; 404/84.1; 404/84.2 |
Current CPC
Class: |
E01C
19/006 (20130101); E01C 19/40 (20130101) |
Current International
Class: |
E01C
23/07 (20060101); E01C 23/085 (20060101) |
Field of
Search: |
;404/83,118,101,102,104,114,84.05-84.8,120 ;172/4.5 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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3623570 |
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Jan 1988 |
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DE |
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0102060 |
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Jul 1984 |
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EP |
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0102060 |
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Jul 1984 |
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EP |
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1182385 |
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Feb 1970 |
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GB |
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1047961 |
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Feb 1989 |
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JP |
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53878 |
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Sep 1942 |
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NL |
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9401774 |
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Mar 1996 |
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NL |
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9401812 |
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Jan 1994 |
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WO |
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Other References
Spectra-Physics BLADE-PRO Motorgrader Control System Owner's
Manual; 1992. cited by other .
Screed King, TSK 308 Brochure published more than one year prior to
filing date of current application. cited by other .
Scrrr-eed Concrete Screed Attachment by Van-Boh Systems, Inc.
Brochure dated Jan. 1998. cited by other .
English-language abstract of previously submitted European Patent
0102060. cited by other .
English-language abstract of previously submitted German patent
DE3623570. cited by other .
English-language abstract of previously submitted Netherlands
Patent NL9401774. cited by other .
Exhibit D Partial English-language translation of previously
submitted German Patent DE3623570 (column 5, line 13, to end of
specification). cited by other .
European Search Report dated Feb. 19, 2002 for application EP 99 30
8506, which is a foreign counterpart to the present application,
namely U.S. Appl. No. 09/792,760. cited by other .
Examiner report dated Jul. 24, 2002 from the Australian Patent
Office regarding Australian patent application 52585/99, which is
the Australian counterpart to the grandparent of the present
application, namely U.S. Appl. No. 09/179,648. cited by other .
Walt Moore, "Grade-Control System Creates Virtual Stringline,"
Construction Equipment, Mar. 18, 1998, pp. 105-106. cited by other
.
Trimble, "Site Vision GPS Automatic Grade Control System: Technical
Notes, " pp. 1-8, Copyright 1997-2001. cited by other .
Topcon, "Motorgrader System Four Plus" brochure, Copyright 1998.
cited by other.
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Primary Examiner: Addie; Raymond
Attorney, Agent or Firm: Van Dyke, Gardner, Linn &
Burkhart, LLP
Claims
The embodiments of the invention in which an exclusive property or
privilege is claimed are as follows:
1. A surface smoothing device comprising: a contouring assembly
having a first and second end, said contouring assembly able to be
moved over an area to be contoured to contour at least one of
material positioned on a reference surface and the material of the
reference surface to a desired surface shape; a stored profile of
the desired shape of the surface; a first sensing apparatus that
uses a first method to sense the position and height of said first
end of said contouring assembly, the height of said first end of
said contouring assembly being sensed without respect to the
reference surface; a second sensing apparatus that uses a second
method to sense the .[.position and.]. height of said second end of
said contouring assembly .Iadd.above one of the material positioned
on a reference surface and the material of the reference surface
adjacent said contouring assembly.Iaddend., said second method
being different from said first method; and a controller that
adjusts the height of said first end of said contouring assembly
based on the position and height sensed by said first sensing
apparatus and said stored profile and that .Iadd.independently
.Iaddend.adjusts the height of said second end of said contouring
assembly based on the .[.distance between said second end of said
contouring assembly and a physical reference.]. .Iadd.height sensed
by said second sensing apparatus of said second end of said
contouring assembly above one of the material positioned on a
reference surface and the material of the reference surface
.Iaddend.adjacent said contouring assembly.[., such as the
reference surface, a previously placed paved surface, a rail, a
board, a string or a wire.]. .
2. The device of claim 1 wherein said contouring assembly includes
a screed that screeds uncured concrete.
3. The device of claim 2 further including an auger positioned
adjacent a side of said screed, said auger oriented substantially
parallel to said screed.
4. The device of claim 3 further including a plow positioned
adjacent a side of said auger opposite said screed such that said
auger is intermediate said plow and said screed, said plow oriented
substantially parallel to said auger.
5. The device of claim 4 wherein said contouring assembly is
mounted on a boom cantilevered from a base, said contouring
assembly able to be moved toward side base on said boom for
spreading and smoothing the uncured concrete.
6. The device of claim 2 wherein said controller adjusts the height
of said first end of said contouring assembly by controlling a
fluid cylinder attached to said first end of said contouring
assembly.
7. The device of claim 6 wherein said controller sends at least one
pulse width modulated control signal to a valve that controls the
fluid flow to said hydraulic cylinder.
8. The device of claim 1 wherein said first sensing apparatus
comprises: a target positioned on said first end of said contouring
assembly; a tracking device that tracks the movement of said target
as said target is moved, said tracking device able to measure the
position of said target in three dimensions; and, a transmitter
that transmits the three dimensional position measurement to said
controller.
9. The device of claim 1 wherein said second sensing apparatus
comprises a proximity sensor positioned on said second end of said
contouring assembly.
10. The device of claim 1 wherein said surface smoothing device
includes a base able to be positioned adjacent a surface to be
smoothed, said contouring assembly mounted for movement with
respect to said base while said base remains stationary whereby
said surface is contoured by said contouring assembly.
11. .Iadd.A surface smoothing device comprising: a contouring
assembly having a first and second end, said contouring assembly
able to be moved over an area to be contoured to contour at least
one of material positioned on a reference surface and the material
of the reference surface to a desired surface shape; a stored
profile of the desired shape of the surface; a base able to be
positioned adjacent the surface to be smoothed, said contouring
assembly mounted for movement with respect to said base while said
base remains stationary whereby said surface is contoured by said
contouring assembly;.Iaddend. .[.The device of claim 10 wherein.].
.Iadd.a first sensing apparatus that uses a first method to sense
the position and height of said first end of said contouring
assembly, the height of said first end of said contouring assembly
being sensed without respect to the reference surface,
.Iaddend.said first sensing apparatus .[.comprises.].
.Iadd.comprising .Iaddend.a tracking laser and an infrared sensor
positioned remotely from said base and a target positioned on said
first end of said contouring assembly, said infrared sensor able to
sense an infrared source on said target and said tracking laser
able to track the movement of said target.Iadd.; a second sensing
apparatus that uses a second method to sense the height of said
second end of said contouring assembly, said second method being
different from said first method; and a controller that adjusts the
height of said first end of said contouring assembly based on the
position and height sensed by said first sensing apparatus and said
stored profile and that adjusts the height of said second end of
said contouring assembly based on the distance between said second
end of said contouring assembly and a physical reference adjacent
said contouring assembly.Iaddend..
12. The device of claim 11 wherein said second sensing apparatus
comprises an ultrasonic sensor.
13. The device of claim 1 wherein said first and second sensing
apparatuses operate without physically contacting the ground.
14. The device of claim 1 wherein said first sensing apparatus
utilizes global positioning satellites to sense the position and
height of said first end of said contouring assembly.
15. A surface contouring device for contouring a surface over a
sub-grade comprising: a base; a boom movably mounted on said base;
a contouring assembly mounted on said boom, said contouring
assembly having a first end and a second end, said contouring
assembly mounted on said boom for movement with respect to said
base and able to smooth a surface while being moved on said boom
while said base remains stationary; and, a control system able to
independently adjust the heights of said first and second ends of
said contouring assembly as said contouring assembly moves whereby
said contouring assembly is capable of smoothing a three
dimensional surface, said control system including a first sensor
that senses the height of said first end of said contouring
assembly using a first method, and a second sensor that senses the
height of said second end of said contouring assembly using a
second method, said second method different from said first method,
a least one of said first and second methods sensing the height of
said first or second end of said contouring assembly without
reference to said sub-grade.
16. The device of claim 15 wherein said contouring assembly
includes a vibratory screed and an auger disposed substantially
parallel to said vibratory screed.
17. The device of claim 16 further comprising a pivoting mechanism
able to pivot said vibratory screed and said auger in order to
conform to the three dimensional surface, said pivot mechanism able
to pivot said vibratory screed and said auger about an axis
substantially parallel to said vibratory screed and said auger.
18. The device of claim 15 wherein said control system comprises: a
target positioned at one of said first end of said contouring
assembly and a location remote from said first of said contouring
assembly, a tracking device positioned at the other of said first
end of said contouring assembly and the position remote from said
contouring assembly, said tracking device measuring the position of
said target in three dimensions; and a distance measuring sensor
attached at said second end of said contouring assembly.
19. The device of claim 18 wherein said contouring assembly
includes a vibrating screed able to vibrate and smooth freshly
poured concrete.
20. The device of claim 15 wherein said control system comprises at
least two fluid cylinders able to independently raise and lower
said first and second ends of said contouring assembly.
21. The device of claim 19 wherein said control system includes a
distance measuring sensor for controlling the height of one of said
first said second ends of said contouring assembly.
22. The device of claim 19 wherein said distance measuring sensor
is one of a laser sensor and an ultrasonic sensor.
23. The device of claim 15 wherein said contouring assembly
comprises a plurality of discrete segment pivotally attached
together, said control system able to adjust the heights of each of
said discrete segments independently of each other.
24. The device of claim 15 wherein said control system includes a
position sensor that measures the position of said contouring
assembly in three dimensions.
25. .[.The device of claim 24 wherein said position sensor
comprises:.]. .Iadd.A surface contouring device for contouring a
surface over a sub-grade comprising: a base; a boom movably mounted
on said base; a contouring assembly mounted on said boom, said
contouring assembly having a first end and a second end, said
contouring assembly mounted on said boom for movement with respect
to said base and able to smooth a surface while being moved on said
boom while said base remains stationary; and a control system able
to independently adjust the heights of said first and second ends
of said contouring assembly as said contouring assembly moves
whereby said contouring assembly is capable of smoothing a three
dimensional surface, said control system including a first sensor
that senses the height of said first end of said contouring
assembly using a first method, and a second sensor that senses the
height of said second end of said contouring assembly using a
second method, said second method different from said first method,
at least one of said first and second methods sensing the height of
said first or second end of said contouring assembly without
reference to said sub-grade, said control system further including
a position sensor that measures the position of said contouring
assembly in three dimensions, said position sensor comprising: a
plurality of reference points positioned at known
locations;.Iaddend. a first .Iadd.wire extendably connected to said
contouring assembly and a first one of said plurality of reference
points;.Iaddend. .[.and.]. a second wire .[.having first and second
ends;.]. .Iadd.extendably connected to said contouring assembly and
a second one of said plurality of reference points; and.Iaddend.
.[.a pair of reference points to which the first end of said first
and second wires is affixed; a pair of rollers attached to said
contouring assembly, said first and second wires attached to and
wound on said rollers at said second end, said rollers able to wind
and unwind as said contouring assembly is moved;.]. a .[.pair of.].
.Iadd.plurality of .Iaddend.distance measuring encoders that
measure the .[.number of rotations of said rollers.].
.Iadd.extension of said first and second wires .Iaddend.as said
contouring assembly moves.[.; and a pair of angle encoders that
measure the angles formed between each of said first and second
wires and said contouring assembly.]. .
26. The device of claim 25 further including: a laser beam that
rotates and thereby defines a plane at a specific height; and a
laser sensor disposed on said contouring assembly that detects the
height of said laser sensor with respect to said plane.
27. The device of claim 24 wherein said control system comprises: a
tracking device that tracks the movement of said contouring
assembly and measures the position of said contouring assembly in
two dimensions; a laser beam that rotates and thereby defines a
plane at a specific height; a laser sensor disposed on said
contouring assembly that detects the height of said laser sensor
with respect to said plane; and a gyroscope mounted on said
contouring assembly that measures the orientation of said
contouring assembly.
28. A method for smoothing a surface over a sub-grade to a desired
three dimensional shape, comprising: storing said desired
three-dimensional shape in a computer memory; providing a
contouring assembly having a first and second end; moving said
contouring assembly over said three-dimensional surface to be
smoothed; using a first method to determine the position of said
first end of said contouring assembly in three dimensions as said
contouring assembly moves, said position of said first end of said
contouring assembly being determined without respect to the height
of the sub-grade; adjusting the height of said first end of said
contouring assembly to correspond to the height of said desired
three-dimensional shape; using a second method different from said
first method to determine the height of said second end of said
contouring assembly from a surface independently of the
determination of the position of the first end of said contouring
assembly; and adjusting the height of said second end of said
contouring assembly to maintain a constant height above said
surface.
29. The method of claim 28 wherein the determining of the position
of said first end of said contouring assembly in three dimensions
comprises: positioning a tracking device in a stationary location
at a position remote from said contouring assembly; tracking the
location of said first end of said contouring assembly with said
tracking device; and transmitting the location of said first end of
said contouring assembly from said tracking device to a controller
that controls said first end of said contouring assembly.
30. The method of claim 29 wherein the transmitting of the location
of said first end of said contouring assembly is performed by a
radio link between said transmitting device and said
controller.
31. The method of claim 28 wherein the determining of the height of
said second end of said contouring assembly from the surface is
performed by an ultrasonic proximity sensor.
32. The method of claim 28 wherein the determining of the height of
said second end of said contouring assembly from the surface is
performed by a laser proximity sensor.
33. The method of claim 28 wherein the step of determining the
position of said first end of said contouring assembly in three
dimensions comprises: measuring the distance of said contouring
assembly away from two known reference points; measuring the height
of said first end of said contouring assembly with respect to a
known height reference; measuring the angles formed between each of
said reference points and said contouring assembly; and calculating
the position of said first end of said contouring assembly based on
the measurements of height and distance and the angular
measurements.
34. .Iadd.A method for smoothing a surface over a sub-grade to a
desired three dimensional shape, comprising: storing said desired
three-dimensional shape in a computer memory; providing a
contouring assembly having a first and second end; moving said
contouring assembly over said three-dimensional surface to be
smoothed; using a first method to determine the position of said
first end of said contouring assembly in three dimensions as said
contouring assembly moves, said position of said first end of said
contouring assembly being determined without respect to the height
of the sub-grade, said first method to determine position
comprising:.Iaddend. .[.The method of claim 33 wherein the step of
measuring the distance of said contouring assembly away from two
known reference points comprises:.]. (.Iadd.a) measuring the
distance of said contouring assembly away from two known reference
points by .Iaddend.affixing the ends of two wires to said
contouring assembly.[.;.]. .Iadd., .Iaddend.affixing the other ends
of said two wires to separate .Iadd.ones of the .Iaddend.reference
points positioned at known locations.[.;.]. .Iadd., .Iaddend.and
determining the length of each of said two wires from said
contouring assembly to each said reference point.Iadd.; (b)
measuring the height of said first end of said contouring assembly
with respect to a known height reference; (c) measuring the angles
formed between each of said reference points and said contouring
assembly; and (d) calculating the position of said first end of
said contouring assembly based on the measurements of height and
distance and the angular measurements; adjusting the height of said
first end of said contouring assembly to correspond to the height
of said desired three-dimensional shape; using a second method
different from said first method to determine the height of said
second end of said contouring assembly from a surface independently
of the determination of the position of the first end of said
contouring assembly; and adjusting the height of said second end of
said contouring assembly to maintain a constant height above said
surface.Iaddend..
35. .[.The method of claim 28 wherein the steps of determining.].
.Iadd.A method for smoothing a surface over a sub-grade to a
desired three dimensional shape, comprising: storing said desired
three-dimensional shape in a computer memory; providing a
contouring assembly having a first and a second end; moving said
contouring assembly over said three-dimensional surface to be
smoothed; using a first method to determine the position of said
first end of said contouring assembly in three dimensions as said
contouring assembly moves, said position of said first end of said
contouring assembly being determined without respect to the height
of the sub-grade, said first method to determine .Iaddend.the
position of said first end of said contouring assembly in three
dimensions .[.comprises.]. .Iadd.comprising.Iaddend.:
(.Iadd.a.Iaddend.) determining the location of said first end of
said contouring assembly in two dimensions with respect to a first
reference; and (.Iadd.b.Iaddend.) determining the location of said
first end of said contouring assembly in a third dimension with
respect to a second reference; .Iadd.adjusting the height of said
first end of said contouring assembly to correspond to the height
of said desired three-dimensional shape; using a second method
different from said first method to determine the height of said
second end of said contouring assembly from a surface independently
of the determination of the position of the first end of said
contouring assembly; and adjusting the height of said second end of
said contouring assembly to maintain a constant height above said
surface.Iaddend..
36. The method of claim 35 wherein said first and second references
are laser emitting devices.
Description
BACKGROUND OF THE INVENTION
This invention relates generally to methods and devices for
contouring or smoothing freshly poured concrete, sand, gravel,
dirt, or other like loose, spreadable materials, and, more
particularly, to an apparatus and method for contouring and
placement of such materials with a vehicle either positioned
adjacent the materials to be contoured or driven through the
materials to be contoured.
In the past, the screeding or smoothing of uncured concrete by
screeding machines has been primarily limited to flat, one or two
dimensional surfaces. In order to screed a three dimensional
concrete surface, the screeding apparatus was required to follow
predetermined or preset forms, such as wires, boards, or rails,
stationed along both sides of the surface to be screeded. Each end
of the screed would follow the predetermined physical form. By
using preset physical forms of different shapes or slopes on either
side of the surface to be screeded, it is possible to create a
smooth surface having a three dimensional curvature. The use of
present physical forms, however, presents several
disadvantages.
The creation of the physical forms is a labor intensive process
that increases the time and expense necessary to establish a
contoured surface. The preset physical forms also typically only
approximate the desired shape of the surface to be contoured,
thereby decreasing the quality of the contoured surface. For
example, if the physical form consists of a wire, it is virtually
impossible to accurately define a desired curvature. Rather, the
wire approximates the curvature by a series of successive straight
segments. These and other disadvantages of prior screeding
techniques have led to the desire to reduce reliance on preset
physical forms.
In the past, non-concrete contouring machines have been developed
for contouring three dimensional surfaces without the use of preset
physical forms. These devices, however, require contact sensors for
creating a profile of the subbase over which a material is placed
and contoured. These devices have also been limited to earth
grading, asphalt laying, or other non-concrete leveling tasks. An
example of such a prior device is disclosed in U.S. Pat. No.
5,549,412 issued to Malone. This patent discloses a device for
profiling and paving asphalt surfaces in three dimensions. The
paving device includes a data storage device for storing the
profile of the subbase to be contoured. The accuracy of the profile
is dependent upon the frictional and physical characteristics of
the contact sensor with respect to the subbase. The contact nature
of the sensor may introduce errors into the profile creation that
are undesirable.
Some prior art grading machines have also been dependent upon the
profile of the subbase. Such machines can only be effectively used
after the subbase has been contoured to the desired shape. This
increases the amount of work required to screed a concrete surface.
Some prior art grading devices have also required the generation of
the profile by running the sensors over the subgrade prior to the
contouring step. This profile generation step may result in
additional inaccuracies due to alignment errors of the contact
sensor during the contouring step when compared with the profiling
step. This further increases the inaccuracies in the system.
Another disadvantage of the prior art is the required use of
multiple sensors to determine the position of the contouring
structure in three dimensions. For example, in U.S. Pat. No.
4,807,131 issued to Clegg, a grading system is disclosed that uses
a laser reference beam in combination with a pair of wheel
encoders. The laser reference beam is used to establish the
vertical height of the grading blade while the encoders measure the
horizontal position of the grading blade. The use of multiple
sensors increases the complexity and associated cost of the grading
system, and is therefore undesirable for many applications.
SUMMARY OF THE INVENTION
The present invention is an improved device and method for
contouring poured uncured concrete, sand, gravel, dirt, or like
loose, spreadable viscous fluid or plastic materials on the ground
or on suspended decks, parking structures, or other surfaces. The
present invention provides a device and method for contouring three
dimensional curved surfaces without the necessity of preset
physical forms on both sides of the surface to be contoured. The
present invention also provides a simple and effective way for
contouring surfaces that overcomes the measurement inaccuracies of
various prior art machines.
In one aspect, the invention is an improved control system for
controlling a contouring machine while a contouring assembly on the
machine is moved over an area to be contoured. The system includes
a controller for controlling the height of a first end of the
contouring assembly. One of a tracking device and a target are
positioned on the first end of the contouring assembly and the
other of the tracking device and the target is positioned remotely
from the contouring assembly. The tracking device tracks the
position of the target and measures the position of the target in
three dimensions as the assembly is moved over the area to be
contoured. The measurement of the target is used by a controller
which adjusts the height of the first end of the contouring
assembly to correspond to a stored profile of the desired shape of
the surface to be contoured.
According to a second aspect, the invention is a device for
contouring a surface which includes a contouring assembly having
first and second ends. A first sensing apparatus is positioned on
one end of the assembly, while a second sensing apparatus that is
different from the first sensing apparatus is positioned on the
second end of the assembly. A controller adjusts the height of the
first end of the assembly based on a stored profile of the desired
shape of the surface to be contoured. The controller adjusts the
height of the second end of the assembly based on the distance
between the second end of the assembly and a reference surface
along one side of the area to be contoured.
According to a third aspect, the invention is a device for
contouring a surface that includes a boom movable mounted on a
base. A contouring assembly is mounted at an end of the boom
opposite to the base, and the assembly has a first and second end
that are independently adjusted by a control system. As the
contouring assembly is moved over the area to be contoured, the
independent control of the first and second ends of the assembly
allows the device to contour a three dimensional surface.
According to a fourth aspect, the invention is a contouring
assembly for contouring a surface to its desired shape. The
invention includes a support having first and second ends, an
elongated contouring assembly, and a height adjustment mechanism
attached to the support and the contouring assembly. The height
adjustment mechanism is adapted to adjust the height of the
contouring assembly with respect to the support based on the
desired shape of the surface to be contoured. The contouring
assembly is pivotally attached to the support and controlled by a
pivot adjustment mechanism that pivots the contouring assembly
about a pivot axis based also on the desired shape of the surface
to be contouring.
In another aspect, the invention is a method for contouring a
surface to a desired three dimensional shape and includes the steps
of storing the desired three dimensional shape in a computer memory
and providing a contouring assembly having first and second ends.
As the contouring assembly is moved over the area to be leveled,
the position of the first end of the contouring assembly is
determined in three dimensions. The height of the first end of the
contouring assembly is then adjusted to correspond to the height of
the desired three dimensional shape. The distance between the
second end of the contouring assembly and a reference surface is
also determined as the contouring assembly is moved over the area
to be contoured, and the height of the second end of the contouring
assembly is adjusted to maintain a constant height above the
reference surface.
In yet another aspect, the invention is a kit for modifying a
previously existing one or two dimensional or screeding machine in
order to allow it to be capable of contouring three dimensionally
curved surfaces. The kit is preferably adapted for use with
previous one or two dimensional leveling machines which include a
leveling assembly with first and second ends that are each
uniformly controlled by height adjustment mechanisms. The kit
includes a target for attaching to either the first or the second
end of the leveling assembly, and a tracking device that tracks the
target and measures its position in three dimensions. A control
system is included with the kit that operates each height
adjustment mechanism independently of the other based on the
measured position of the target. The independent control of the
height adjustment mechanisms allows a three dimensionally curved
shape to be contoured, if desired. In different embodiments, the
kit may include different components. For example, the kit may
include a segmented screed, in addition to the previously listed
components, to allow screeding a surface the approximates a higher
degree of curvature. In other embodiments the kit may include a
pair of wires for attaching to two separate reference points, a
pair of distance encoders that measure the length of the wires as
the leveling or smoothing assembly moves, and a pair of angle
encoders that measure the angles defined between the wires and the
leveling assembly. A control system is included in the kit that
determines the position of the leveling assembly based on the
length of each of the wires from the two reference points.
In another aspect, the invention is a contouring machine comprising
a screed for spreadable materials including poured, uncured
concrete, a height adjustment mechanism for adjusting the height of
the screed on the contouring machine, a target, a tracking device
which tracks the target and measures the position of the target in
at least two dimensions, one of the target and tracking device
positioned on the machine and the other of the target and tracking
device positioned at a location remote from the machine, and a
controller for controlling the height adjustment mechanism based on
the position of the target with respect to the tracking device.
This aspect of the invention also includes a method for moving the
screed over the spreadable material and adjusting the height of the
screed as the screed is moved over the spreadable material such
that the spreadable material is contoured.
Accordingly, the present contouring device and method provide
improvements and advantages over prior contouring devices and
methods. The invention allows the smoothing of either a one, two,
or three dimensional curved surface without the use of contact
sensors, and also without the use of preset physical forms on both
sides of the contouring device. The present invention thereby
eliminating substantial time and labor expenses while providing
improved accuracy in the final, contoured surface. The use of a
single measuring device for tracking the position of one end of the
contouring assembly further reduces the complexity and cost of the
invention. The invention does not require passing the device over
the surface to be contoured prior to the actual contouring step,
thereby reducing the number of steps involved in the contouring
process. Moreover, the contouring device does not have to be moved
in a predetermined direction during the contouring process, thereby
simplifying the contouring procedure. The invention can smooth a
surface either independently of the subbase, or dependent on the
subbase, if desired. The invention can also be used as a kit to
retrofit existing leveling machines that are only capable of
smoothing one or two dimensional surfaces.
These and other objects, advantages, purposes, and features of the
invention will become more apparent from the study of the following
description when read in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a first embodiment of the
contouring device according to the present invention;
FIG. 2 is an elevational view of the contouring device of FIG. 1
illustrating the movement of a boom in phantom;
FIG. 3 is a plan view of the contouring device of FIG. 1
illustrating the movement of the boom in phantom;
FIG. 4 is a schematic illustration of the contouring device and
tracking device;
FIG. 5 is a block diagram of a control system for controlling a
first end of a contouring assembly on the contouring device;
FIG. 6 is a block diagram of a hydraulic control system for the
contouring assembly;
FIG. 7 is an exploded, perspective view of the contouring
assembly;
FIG. 8 is an enlarged, fragmentary, perspective, exploded view of a
tilting assembly for tilting the contouring assembly;
FIG. 9a is an enlarged, fragmentary, elevational view of the
contouring assembly of the present invention depicted in an
unrotated orientation;
FIG. 9b is an enlarged, fragmentary, elevational view of the
contouring assembly depicted as rotated in a counter-clockwise
orientation;
FIG. 9c is an enlarged, fragmentary, elevational view of the
contouring assembly depicted as rotated in a clockwise
direction;
FIG. 10 is a flowchart illustrating the method of the present
invention for contouring a three dimensional surface;
FIG. 11 is a flowchart illustrating a method for creating a stored
profile of the desired surface to be contoured;
FIG. 12 is a front, elevational view of a contouring device
according to a second embodiment of the present invention;
FIG. 13 is a plan view of a contouring device according to a third
embodiment of the present invention; and
FIG. 14 is a plan view of a contouring device according to a fourth
embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will now be described with reference to the
accompanying drawings wherein like reference numerals correspond to
like elements in the several drawings. A contouring device or
machine 20 according to the present invention is depicted in FIG.
1. Contouring machine 20 includes a base 22 upon which an operator
24 controls contouring machine 20. Base 22 includes a platform 38
upon which an upper frame 40 is rotatably mounted. Base 22 can be
moved to any desired location by wheels 42 which are powered by a
motor onboard base 22. Platform 38 is securely planted at a desired
location by four stabilized legs 44 that are retractable when
contouring machine 20 is driven to different locations. A boom 26
is telescopingly mounted on a front end of upper frame 40. A
support beam 27 is affixed to boom 26 at an end opposite upper
frame 40. A contouring member preferably includes a contouring
assembly 28 mounted on support 27 by way of a right and left
hydraulic cylinder 52 and 54, respectively. Hydraulic cylinders 52
and 54 independently raise and lower the respective ends of
contouring assembly 28 with respect to support 27. Other than the
controls for independently controlling the individual ends of
contouring assembly 28 and tilting it about an axis as depicted in
FIGS. 9a-c, the structure of contouring machine 20 is the same as
that disclosed in commonly assigned U.S. Pat. No. 4,930,935 issued
to Quenzi et al., and which is incorporated herein by
reference.
When contouring machine 20 is to be used to contour a surface, it
is positioned adjacent an area of raw material 30 which is to be
contoured (FIGS. 2 and 3). For purposes of discussion hereafter, it
will be assumed that material 30 is freshly poured, uncured
concrete, and that the contouring machine includes a screed or
contouring unit or member adapted for spreading, distributing,
smoothing, leveling and/or grading such uncured concrete. This
assumption is for purposes of discussion only, and it will be
understood that material 30 can be any of a variety of other loose,
gradable materials, such as dirt, sand, or earth. It will also be
further understood that contouring machine 20 can be used to smooth
material 30 to have a one, two, or three dimensional surface. The
contouring member could also be a blade or other earth moving or
material moving device. In operation, the boom 26 is extended away
from upper frame 40. Preferably, concrete 30 is deposited in the
area to be contoured prior to boom 26 being extended. Thereafter,
boom 26 is extended over the poured concrete without contacting the
concrete. The boom is then retracted toward and into upper frame 40
while contouring assembly 28 contours the uncured concrete 30 as
boom 26 is retracted. Alternately, machine 20 can be moved through
the concrete, or other material, as set forth in Quenzi U.S. Pat.
No. 4,930,935.
Contouring assembly 28 includes a right and left side 46 and 48,
respectively, as viewed from operator position 24 (FIGS. 1-3).
Support 27 extends between right and left sides of contouring
assembly 28. Right hydraulic cylinder 52 is mounted at right end 46
of support 27 and adjustably raises and lowers right side 46 of
contouring assembly 28 with respect to support 27. Left hydraulic
cylinder 54 is mounted on left side 48 of support 27 and adjustably
raises and lowers left side 48 of contouring assembly 28 with
respect to support 27. By independently controlling right hydraulic
cylinder 52 and left hydraulic cylinder 54, the cross slope of
contouring assembly 28 can be adjusted as desired in a plane
transverse to the direction of motion of contouring assembly 28
when boom 26 is retracted. By adjusting the cross slope of
contouring assembly 28, a three dimensional curved surface can be
produced over a given large area by contouring machine 20.
Alternatively, by adjusting the height of right and left sides 46
and 48 of contouring assembly 28 uniformly, a one or two
dimensional surface can be created.
Contouring assembly 28 preferably includes one or more of a plow
32, a vibrating screed or contouring beam 34, and a rotating auger
36 (FIGS. 1, 2, 7 and 9a-9c). Plow 32, screed 34, and auger 36 all
extend generally parallel to each other and are oriented transverse
to the direction of motion of contouring assembly 28 as it is
extended and retracted by boom 26. Plow 32, auger 36, and screed 34
are all mounted on a center beam 29 that extends parallel to plow
32, auger 36 and screed 34. Plow 32 is positioned on a leading side
41 of contouring assembly 28 (when boom 26 is being retracted) and
serves to push excess concrete away from auger 36 and vibrating
screed 34 while also determining the initial grade for the concrete
or other material 30. Auger 36 is positioned between plow 32 and
vibrating screed 34 and extends downwardly approximately 3/4 of an
inch further than plow 32. A motor 43 attached at left side 48 of
center beam 29 rotates auger 36. Auger 36 rotates and moves the
excess concrete or material 30 in a direction from left side 48
toward right side 46, although motion in the opposite direction
from right side 46 to left side 48 could also be used. Vibrating
screed or contouring beam 34 is located adjacent auger 36.
Vibrating screed 34 is constructed to vibrate by way of an
eccentrically weighted motor system as disclosed in commonly
assigned U.S. Pat. No. 4,930,935, and smooths the uncured concrete
as it passes over the area to be contoured, after plow 32 and auger
36 have removed excess concrete and spread and distributed the
concrete generally evenly across the path of travel of assembly 28.
Screed 34 extends downwardly approximately 1/4 of an inch farther
than auger 36.
Leveler assembly 28 can also include, if desired, an oscillating
engaging member (not shown) of the type described and disclosed in
commonly assigned, copending application entitled SCREEDING
APPARATUS AND METHOD INCORPORATING OSCILLATING ATTACHMENT, filed
Mar. 31, 1998, which is incorporated herein by reference. As
described therein, an oscillating engaging member is located
between auger 36 and screed 34 and oriented generally parallel
thereto. The oscillating member oscillates in its longitudinal
direction, parallel to contouring assembly 28, and further serves
to smooth and distribute the concrete prior to the final leveling
of screed 34.
A target 56 is located atop right hydraulic cylinder 52 (FIGS.
1-5). Target 56 comprises an infrared heat source and comer-cube
laser reflecting mirror. The position of target 56 is tracked by an
infrared tracking device 58 (FIGS. 4-5) as contouring assembly 28
is moved over the surface to be contoured. In the currently
preferred embodiment, tracking device 58 emits a laser beam 60 that
is reflected by target 56 back to tracking device 58. From the
reflected beam, tracking device 58 computes the distance between
itself and target 56. Tracking device 58 further includes servo
motors and infrared sensors which control the orientation of
emitted laser beam 60 such that it will follow (i.e. track) target
56 wherever it is moved. From the distance measured to target 56
and the angles measured by tracking device 58 at which laser beam
60 is emitted from tracking device 58, tracking device 58 is able
to calculate the position of target 56 in three dimensions (e.g. X,
Y, and Z) from a known reference point. Tracking device 58 further
includes a radio transmitter that transmits the measured position
of target 56 to a receiver 62 on base 22. In the currently
preferred embodiment, tracking device 58 provides an updated
measurement of the position of target 56 approximately four times
every second. This frequency of position measurement updating has
been found to be sufficient in the current embodiment. Other
frequencies can, of course, be used. Tracking device 58 is a
commercially available device, such as automatic tracking
system-machine control (ATS-MC) available from
Geotronics/Spectra-Precision of Dayton, Ohio, and the internal
structure will not be described further herein. Target 56 is a
combination corner cube laser reflector and infrared heat source
which is also commercially available in conjunction with tracking
device 58. An acceptable target for carrying out the present
invention is manufactured by Geotronics/Spectra Precision from
Dayton, Ohio, under model No. Tracker Target (RMT 360). Other
commercially available tracking and target measurement systems may
also be acceptable.
The position of target 56 as measured by tracking device 58 is
transmitted through a radio modem 64 (FIG. 5) to a control system
55 for controlling right side 46 of contouring assembly 28. Control
system 55 receives the transmitted position information at a second
radio modem 66 on contouring machine 20. Radio modem 66
communicates the position information through a communications port
68 which forwards the position information to a tracking processor
70. Tracking processor 70 takes the received position information
from tracking device 58 and translates the position information
from tracking device 58's frame of reference to the site frame of
reference. Tracking device 58 only measures position information
with respect to itself, and processor 70 converts this into
position information with respect to the site to be leveled. The
translation of coordinate frames of reference is based upon an
initialization procedure undertaken prior to contouring, which is
described more fully below. Tracking processor 70 outputs the
translated position information (X, Y, and Z) to a main processor
72. Main processor 72 has access to the profile of the desired
shape of the surface to be contoured stored in some form of memory,
such as RAM (not shown). Main processor 72 compares the translated
position information received from tracking processor 70 with the
coordinate information of the stored profile of the surface to be
contoured. Main processor 72 then calculates the difference in the
measured height (Z axis) of right side 46 of contouring assembly 28
and the corresponding desired height (Z axis) in the stored
profile. As an example, if tracking processor 70 transmits to main
processor 72 measured location information of X=10, Y=15, and Z=5,
main processor 72 will search the stored profile for the stored Z
coordinate (height) at the location X=10 and Y=15. Main processor
72 will then compare the Z coordinate (height coordinate) stored in
memory with the measured Z axis coordinate received from tracking
processor 70. The difference between these two Z axis coordinates
represents an error of the height of right side 46 of contouring
assembly 28. In this example, if the stored Z axis coordinate at
X=10 and Y=15 is 3, then the error signal will be 2.
Main processor 72 transmits the error signal to a pulse width
modulated processor 74. Pulse width modulated processor 74
generates a pulse width modulated signal that is proportional to
the error signal it received from main processor 72. The pulse
width modulated signal is output to one of two solenoid valves 86
and 88 that control right hydraulic cylinder 52 (FIGS. 5-6).
Solenoid valves 86 and 88 control oil flow in hydraulic system 80
of contouring machine 20. The height of right side 46 of contouring
assembly 28 is thereby adjusted to currently correspond to the
stored profile of the surface to be contoured. The control of right
hydraulic cylinder 52 is independent of the control of left
hydraulic cylinder 54, which is described below.
Right and left hydraulic cylinders 52 and 54 are controlled by a
single hydraulic system 80 illustrated in FIG. 6. Hydraulic system
80 includes a hydraulic pump 82 and a manifold 84 that branches out
to right and left hydraulic cylinders 52 and 54. A right raise
solenoid valve 86 controls the flow of hydraulic fluid to right
cylinder 52 such that right cylinder 52 is raised. Right lower
solenoid valve 88 controls the flow of hydraulic fluid to right
cylinder 52 such that right cylinder 52 is lowered. Left lower
solenoid valve 90 and left raise solenoid valve 92 similarly
control the lowering and raising of left hydraulic cylinder 54,
respectively. As described above, right solenoid valves 86 and 88
are controlled by a control system 55 depicted in FIG. 5. Left
solenoid valves 90 and 92 are controlled based upon the output of a
distance measuring sensor 78, described below. Solenoid valves 86,
88, 90, 92 may be any of conventional solenoid operated, hydraulic
valves which are electrically operated to either fully open or
fully close. Alternately, valves 86, 88, 90, 92 may be proportional
hydraulic valves which variably adjust between fully open and fully
closed positions in proportion to the electrical voltage
applied.
Left hydraulic cylinder 54 is controlled by a separate control
system than that used to control right hydraulic cylinder 52. Left
hydraulic cylinder 54 is controlled based upon a distance detected
by a proximity sensor or distance measuring sensor 78 attached at
left side 48 of contouring assembly 28 (FIGS. 1, 2, and 9a-9c).
Distance measuring sensor 78 measures its vertical distance above
whatever reference surface or form it is located over. Typically
the distance measuring sensor 78 will be located above a previously
contoured section of concrete. However, distance measuring sensor
78 may alternatively be positioned over any of a variety of
different preset physical forms. In either case, distance measuring
sensor 78 will provide a signal representing its distance from the
surface below it. The signal provided by distance measuring sensor
78 is communicated to a separate controller (not shown) that
adjusts the height of left side 48 of contouring assembly 28 in
order to maintain in at a desired height. The controller for left
side 48 of contouring assembly 28 adjusts the height of left side
48 by controlling left hydraulic cylinder 54. Distance measuring
sensor 78, along with its associated controller, ensures that the
surface contoured by contouring machine 20 will smoothly correspond
to a previously contoured surface to the left of and adjacent to
the surface currently being contoured. In the currently preferred
embodiment, distance measuring sensor 78 is an ultrasonic sensor,
which may be of the type sold by Spectra-Physics of Dayton, Ohio
under model no. ST2-20. It will be understood, however, that
distance measuring sensor 78 can be any of a variety of different
technology based sensors, such as laser sensors, mechanical
sensors, or other types.
As best seen in FIG. 8, contouring assembly 28 is preferably
pivotally mounted about a pair of orthogonal pivot axes at each end
of the contouring assembly 28 with respect to support beam 27 by
means of a tilting assembly 83. The mechanical structure for
tilting contouring assembly 28 is the same as that disclosed in
commonly assigned U.S. Pat. No. 4,930,935 issued to Quenzi et al.
Each tilting assembly 83 includes a rectangular pivot yoke 85 that
is fitted between laterally spaced portions of a pair of end plates
87, 87a and that is secured for pivotal movement in a vertical
plane on a generally horizontal axis 118 extending parallel to the
direction of elongation of the contouring assembly 28 by means of
securing bolts 89 and bushings 91 passing through end plates 87,
87a and pivot yoke 85 (FIGS. 7 and 8). A hydraulic fluid cylinder
95 is pivotally secured to the upright end plates 87, 87a by means
of a laterally extending pivot axle 97 secured to one end of the
cylinder and pivotally mounted in bushings 99 extending inwardly
from end plates 87, 87a. A cylinder rod 101 extends from the
opposite end of fluid cylinder 95 and is secured by a pivot pin 103
between a pair of spaced upright plates 105 which are rigidly
secured to one end of pivot yoke 85. The horizontal pivot axis 118
provided by yoke 85 and bolts and bushings 89, 91 is vertically
aligned and centered above the rotational axis of auger 36.
Accordingly, operation of the fluid cylinder 95 to retract cylinder
rod 101 causes counterclockwise rotation of the contouring assembly
28 about axis 118 on bolts and bushings 89, 91 as shown in FIG. 9b,
thereby raising plow 32 and lowering vibratory screed 34 (Step 119
of FIG. 5). Extending cylinder rod 101 raises vibratory screed 34
and lowers plow 32 by causing clockwise rotation around horizontal
pivot axis 118 (Step 117 of FIG. 5; FIG. 9c). In either case, since
the rotational auger 36 is vertically aligned with the pivot axis
118, rotation via fluid cylinder 95 causes little variation in the
position or height of rotational auger 36. Accurate positioning of
plow 32 ahead of auger 36 and vibratory screed 34 prevents
"tearing" of the concrete surface which could otherwise occur if
the plow 32 followed the auger 36. "Tearing" of the smoothed,
contoured surface is also prevented by maintaining a constant
vertical relationship between plow 32, auger 36, and vibratory
screed 34 despite any deflection of boom 26 caused by gravity or
sloped working surfaces. Contouring machine 20 can also be equipped
with a self-leveling system such as that disclosed in commonly
assigned U.S. Pat. No. 4,930,935. The self-leveling system is
employed when an essentially flat surface is to be smoothed.
It will be understood that alternate power sources other than
cylinders 95 may be substituted to rotate contouring assembly 28 on
axis 118 such as hydraulic motors that rotate threaded rods which
engage pivotable members on yokes 85.
Contouring assembly 28 is mounted on a rectilinear leveler assembly
support beam 27 secured to the underside of boom 26 such that
support beam 27 extends parallel to the axial extent of contouring
assembly 28 (FIG. 8). At left and right sides of support 27, right
and left hydraulic cylinders 52 and 54 are respectively mounted.
Each hydraulic cylinder includes a vertically extending cylinder
tube 53 through which is slidably mounted an inner elevation tube
57 on bearings pressed inside tube 53. The lower end of each inner
elevation tube 57 includes a tubular pivot foot 61 (FIG. 8) which
is slightly smaller than the internal lengthwise dimension of pivot
yoke 85 such that it may be pivotally secured inside yoke 85 by a
pivot bolt 63. Pivot bolt 63 passes through the yoke in a direction
perpendicular to the horizontal direction of elongation of
contouring assembly 28 and the horizontal pivot axis 118 provided
by bolts 89 and bushings 91 described above. Pivot bolts 63 at
either end of the contouring assembly on elevation tubes 57 allow
the lateral tilt of the contouring assembly to be adjusted by
raising and lowering tubes 57. Thus, the lateral incline or slope
of support beam 27, and thus plow 32, auger 36, and vibratory
screed 34 mounted thereon may be adjusted with respect to beam 27
to various slopes and ground contours, thereby permitting
contouring of a three dimensionally curved surface over a
relatively large area.
OPERATION OF CONTOURING MACHINE 20
The steps of operation of contouring machine 20 are depicted in
FIG. 10 in flowchart form. An initial step 94 requires the creation
of a computer map of the desired surface profile to be contoured.
The surface profile information can be taken from either actual
measurement data from the work site (step 120), or it may be based
on architectural data from a theoretical work site plan (step 122).
Regardless of its source, the surface profile map is then loaded
and stored in a computer on board the contouring machine 20 during
an initial step 96. An example of the general algorithm for
creating this profile is described below, although it will be
understood that a variety of different algorithms may be used
within the scope of the invention.
In initialization step 98, the location of tracking device 58 with
respect to the site is determined (FIG. 10). Initialization step 98
is required because tracking device 58 can be positioned anywhere
within approximately a one mile radius in sight of the surface to
be contoured. Without knowing the position of tracking device 58
relative to the site, the position information transmitted from
tracking device 58 would be of no value to contouring machine 20.
Therefore, the position of tracking device 58 must be determined
relative to the work site. While initialization step 98 can be done
in a variety of ways, one acceptable way is to carry a portable
target 56A (not shown) to several known site locations and read and
record the measurements produced by tracking device 58. By taking
at least three such measurements, the correlation between the
tracking device 58 frame of reference and the work site frame of
reference can be established.
After initialization, the retraction of boom 26 begins the movement
of contouring assembly 28 over the area to be contoured. As
contouring assembly 28 moves over the surface to be contoured, the
three dimensional location (i.e. X, Y, and Z) of target 56 is
continuously measured by tracking device 58 (step 100) (FIG. 10).
The position of target 56 relative to tracking device 58 is
transmitted to tracking processor 70 where this position
information is translated to the frame of reference of the site
(step 102). The translation of step 102 is based upon the
information obtained during initialization step 98. At step 104,
main processor 72 looks up the height (Z value) of the stored
profile corresponding to the X,Y location of target 56 as
determined by tracking device 58. From the stored work site map
profile, main processor 72 determines what Z value target 56 should
be at for that X, Y location. Main processor 72 then compares the
desired Z value from the stored profile with the measured Z value
transmitted from tracking device 58.
At step 106 (FIG. 10) main processor 72 calculates a height error
signal, which is the difference between the desired Z value from
the stored work site map profile and the measured Z value from
tracking device 58. The error signal is transmitted from main
processor 72 to pulse width modulated processor 74. At step 107
pulse width modulated processor 74 computes a pulse width modulated
control signal that is transmitted to either right raise solenoid
valve 86 or right lower solenoid valve 88, depending upon the sign
of the error signal. The width of the pulse width modulated signal
corresponds to the magnitude of the error signal calculated by main
processor 72. The width of the pulse width modulated signal is also
dependent upon the sign of the error signal calculated by main
processor 72 because different volumes of hydraulic fluid have to
be metered depending upon which direction (up piston side or down
rod side) of right hydraulic cylinder 52 is to be moved. The up or
down movement of right hydraulic cylinder 52 moves right side 46 of
contouring assembly 28 up or down independently of left side 48.
Contouring machine 20 is thereby capable of not only contouring
flat surfaces, but also approximating three dimensionally curved
surfaces.
In addition to the vertical adjustability of contouring assembly 28
via hydraulic cylinders 52 and 54, contouring assembly 28 can also
be pivoted or tilted about an axis 118, as discussed previously
(FIGS. 9a-9c). After step 102, the tilt (i.e. pitch) of contouring
assembly 28 is optionally adjusted based on the stored work site
map profile of the surface to be contoured (FIG. 10). The control
of the tilt of contouring assembly 28 is optionally performed in
steps 104B, 110, and 112 by computer 72. Steps 104B, 110, and 112
are optional because contouring machine 20, in one embodiment, may
not include the ability to tilt contouring assembly 28. In step
104B, computer 72 determines the actual slope of contouring
assembly 28 relative to the work site. The determination of the
actual slope of contouring assembly 28 by computer 72 can be
accomplished by any of a variety of known sensors for measuring
tilt. In step 110 main processor 72 calculates the slope of the
stored profile for the current location of target 56. At step 112,
main processor 72 outputs a digital tilt control signal to a DAC
(Digital to Analog Conversion) board 114, which converts the
digital signal to an analog signal in the current embodiment of
this invention. DAC board 114 then passes the analog tilt control
signal on to a tilt controller 116 (FIG. 5). The tilt control
signal alters the tilt of contouring assembly 28 as illustrated in
FIGS. 9a-9c. If the slope of the stored profile is horizontal,
contouring assembly 28 is not tilted, as illustrated in FIG. 9a. If
the slope of the stored profile is positive in the direction that
contouring assembly 28 moves, contouring assembly 28 is rotated
counterclockwise (positive slope) as illustrated in FIG. 9b. The
extent of rotation corresponds to the slope of the stored profile.
If the stored profile is sloping in an opposite direction,
contouring assembly 28 is tilted in a clockwise direction (negative
slope), as illustrated in FIG. 9c. Again, the degree of rotation
corresponds to the slope of the stored profile. The tilting of
contouring assembly 28 allows contouring machine 20 to smooth a
surface that more accurately corresponds to the desired
profile.
Tracking profile 70, in addition to performing frame of reference
translations, monitors the received transmissions from tracking
device 58. If tracking processor 70 does not receive a transmission
from tracking device 58 for a time exceeding 2 to 5 seconds,
tracking processor 70 concludes that tracking device 58 has lost
track of target 56. Tracking device 70 outputs a corrective signal
instructing tracking device 58 to switch into a search mode. The
corrective signal passes through communications port 68 to radio
modem 66 where it is transmitted by radio to tracking device 58.
When tracking device receives the corrective signal, it switches to
a search mode. In the search mode, tracking device 58 moves an
infrared sensor "eye" (not shown) over the area where target 56 was
last detected in an effort to relocate target 56 and its infrared
heat source. The search mode is part of the commercially available
tracking devices that are suitable for use in the present
invention. The algorithm used to control the movement of laser beam
60 when tracking device 58 is in the search mode can be altered
from that built into the commercially available tracking devices,
if desired. If tracking device 58 does not relocate target 56 in
the search mode, tracking processor 70 sends a signal to main
processor 72. The signal can either cause the retraction of boom 26
to stop automatically, or it can display a message on a display
indicating the target has not yet been found allowing the operator
to manually take appropriate action. If tracking device 58 does
relocate target 56 within the allotted time, tracking device 58
switches out of the search mode and resumes its normal operation of
tracking and transmitting the position of target 56 to tracking
processor 70.
The creation of the desired profile to be contoured is illustrated
in FIG. 11. The profile can be entered into a computer either
directly from site measurements 120 or alternatively from user
entries 122 based upon engineering drawings or some other
previously created compilation of the desired profile. In either
case, the information is input into a file 124 that stores the X,
Y, and Z values for each of the points, or nodes, that are entered
into the computer. Sufficient nodes must be input into file 124 to
define the shape of the surface to be contoured. The computer can
either be the computer on board contouring machine 20, comprising
main processor 72, a keyboard 73, and a display 75, or it may be an
ordinary PC or other computer programmed as discussed herein.
From node file 124, a user selects three or four of these nodes to
define a surface at step 126. These three or four nodes may define
the entire surface to be contoured, or they may only define a
portion of the surface to be contoured, leaving the rest of the
surface to be defined by selecting additional nodes (see step 126).
Based on the selected nodes, the computer creates either a plane or
a curved surface that joins the selected nodes (step 128). If only
three nodes have been selected, the computer calculates three lines
joining these three nodes, thereby creating a triangle and defining
a plane. If the number of nodes that have been selected is four,
then the computer divides the nodes into two pairs and calculates a
line connecting each pair. The computer then calculates two
additional lines joining each pair of nodes to each other to
thereby define a quadrilateral. At step 128, the computer
calculates all the heights, or Z values, for the areas
circumscribed by the triangle or quadrilateral. The calculated Z
values are displayed in step 130. In step 132 the calculated
profile is stored in computer memory for use by contouring machine
20. Control of the profile creation process is returned to step
126, where a user can select additional nodes to create additional
surfaces, or to otherwise complete the profile. The more nodes that
are selected, the more complex the curvature of the profile can be.
While the calculation of the triangles or quadrilaterals joining
the selected nodes, along with the Z values defined by these
shapes, has been described as utilizing the calculation of lines,
it will be understood that other calculation algorithms can be used
within the scope of the invention, such as the calculation of arcs,
interpolation, splining, or any other suitable technique.
The generated profile of the desired shape of the surface to be
contoured can either follow the profile of the subbase or be
independent of the subbase. If the contoured surface is to be
independent of the subbase, nodes are selected having whatever Z
value is desired without regard to the subbase. Variations in the
height of the subbase will show up as variations in the thickness
of the contoured concrete. If the profile is to follow the shape of
the subbase, the profile is created by selecting nodes that are
located at a desired, constant height above the subbase.
Alternatively, nodes defining the subbase can be selected and a
predetermined height (corresponding to the thickness of the
concrete) can be automatically added in software to each of the Z
values for the nodes. In either case, the contoured surface of the
concrete or other material will follow the contours of the
subbase.
The independent control of right side 46 and left side 48 of
contouring assembly 28 allows contouring machine 20 to contour a
three dimensionally curved surface, if desired. If right and left
sides 46 and 48 are controlled to remain at the same height
throughout the screeding process, a two-dimensional surface can be
screeded. If right and left sides 46 and 48 are controlled to have
different heights throughout the screeding process, a three
dimensionally curved surface can be screeded. Distance measuring
unit 78 ensures that left side 48 of contouring assembly 28 will
follow a reference surface, such as a previously screeded section
of concrete, or another surface as desired, such as the ground, or
other physical form. If parallel sections of concrete are screeded,
distance measuring unit 78 ensures that new sections are screeded
seamlessly with the adjacent, existing screeded sections. It will
be understood that target 256 and distance measuring unit 78 can be
switched to opposite sides, if desirable. It will also be
understood that distance measuring unit 78 on left side 48 can be
either replaced or supplemented with another target 256a that is
tracked by another tracking device, as illustrated in FIG. 12.
ALTERNATIVE EMBODIMENTS
FIG. 12 illustrates an alternative embodiment of contouring or
screeding machine 220. Parts corresponding to the previous
embodiment are referenced by the same number increased by 200. In
this embodiment an additional target 256a is included at left side
248 of contouring assembly 228. A second tracking device 258 (not
shown) can be used to track second target 256a. When used in this
manner, distance measuring unit 278 does not need to be used and
the requirement for a preset form or surface along one side of the
surface is not present. The control for left hydraulic cylinder 254
is the same as that disclosed above with respect to right hydraulic
cylinder 52. Alternatively, distance measuring unit 278 can be used
when desired to control left hydraulic cylinder 54. Screeding
machine 220 therefore has the option of controlling left side 48 of
contouring assembly 28 with reference to either a stored profile or
a preset physical form, depending upon what is most suitable for
the application.
Contouring machine 220 can also be modified to include a plurality
of intermediate targets 256b and 256c (FIG. 12). In this
alternative embodiment contouring machine 220 includes a contouring
assembly 228 that is divided into segments 239a-c, which are
pivotally connected to each other. Each end of each segment 239, or
the pivot joint between the segments, is independently controlled
by a separate target 256 mounted on a hydraulic cylinder. A
separate tracking device 258 is used for each target 256. The use
of a segmented contouring assembly 228 allows a higher degree of
lateral (i.e. side-to-side) curvature to be approximated in the
contoured surface. Alternately, the height of each segment can be
controlled by reference to the relative height of the neighboring
segments. In this variation, only a single target and tracking
device are used rather than a separate target and tracking device
for each segment.
In still another embodiment, contouring machine 320 utilizes a
tracking device 358 in combination with a laser beam 359 that is
rotated to define a horizontal plane (FIG. 13). In this embodiment,
tracking device 358 determines only the X, Y location of right side
346 of contouring assembly 328. Right side 346 of contouring
assembly 328 includes a target 356 that is tracked by device 358.
The height, or Z position, of right side 346 of contouring assembly
328 is determined by the impingement of rotating laser beam 359, on
a pair of vertically movable laser arrays (not shown). The laser
arrays consist of a vertical array of laser receivers or sensors.
One of the laser arrays is positioned at right side 346 of the
contouring machine 320 while the other array is positioned at left
side 348. The vertical position of each of the laser arrays is
controlled to ensure that at least one of the sensors in the
vertical array remains in the plane defined by the rotating laser
beam 359. Laser beam 359 will impinge one or more of the laser
sensors that are of the same height as laser beam 359. By
determining which laser sensor is impinged, the array of laser
sensors allows the height of the sides of the contouring assembly
to be determined with respect to the horizontal plane created by
laser beam 359. The X,Y position of left side 348 of contouring
assembly 328 is determined from the output of a directional
gyroscope (not shown) mounted on contouring assembly 328. The
directional gyro is mounted in such an orientation to produce a
signal indicative of the horizontal direction of contouring
assembly 328 (e.g. north, south, etc.). This directional signal
allows a vector to be added to the X, Y, and Z locations of right
side 346 of contouring assembly 328 to thereby determine the
position of left side 348 of contouring assembly 328. In summary,
the X,Y position of right side 346 is determined from tracking
device 358 and target 356 mounted on right side 346. The Z position
of both right and left sides 346 and 348 is determined from the
reference laser plane created by rotating laser beam 359 and sensed
by the pair of sensor arrays on each side of contouring assembly
328. The Z position of left side 348 is determined from the
gyroscope in combination with the known location of right side 346.
Contouring machine 320 has the advantage of not requiring a
tracking device 358 that can track target 356 in three dimensions.
Tracking device 358 can therefore be a simpler and more inexpensive
device than tracking device 58. Contouring machine 320 includes a
base 322 and a telescoping boom 326, and is similarly used to
smooth uncured concrete 330 or other loose, spreadable material to
a desired shape or contour. As with contouring machine 20, the
concrete or other material 331 is contoured either independently
of, or with reference to, the subgrade 333.
In yet another embodiment, shown in FIG. 14, contouring or
screeding machine 420 utilizes a pair of wires 435a, 435b attached
at one end to the center of contouring assembly 428. The other ends
of wires 435 are attached at reference points 437a and b,
respectively, which are of known location. The wires are preferably
made of titanium or other sufficiently strong material. A laser
beam 459 is rotated to define a horizontal plane that is detected
by a vertical array of laser sensors (not shown) on contouring
assembly 428 which is similar to the array of receivers in machine
320 above. The vertical array of laser sensors allows the height of
contouring assembly 428 to be determined. As contouring assembly
428 is moved by telescoping boom 426, wires 435a and b unwind. A
pair of distance measuring encoders .Iadd.461 .Iaddend.are
positioned on the windings of each wire 435a, 435b and the encoders
allow contouring machine 420 to calculate the distance each wire
has extended from reference points 437a, b. By calculating the
length of unwound wires 435a, b, the X,Y position of contouring
assembly 428 is calculated. A pair of angle encoders are also
positioned on wires 435a, 435b and measure the angles between each
wire and contouring assembly 428. From the angular information
provided by the two angle encoders, along with the length of the
contouring assembly, the X,Y position of each end of the contouring
assembly can be determined. The positions of right and left sides
446,448 of contouring assembly 428 are compared by a
microprocessor, or other suitable electronic device, to the desired
position stored in the profile of the surface to be contoured.
Based on the difference between the measured positions and the
desired positions, right and left hydraulic cylinders 452 and 454
are adjusted by a controller (not shown) to follow the desired
profile. The controller may comprise one or more microprocessors
and valves for the hydraulic system, as disclosed in FIG. 5, or
other suitable form. The direction of motion of the leveler 428
(i.e. north, south, etc.) can be determined in a calibration step
when the direction does not change during the leveling pass or it
may be dynamically determined by a gyroscope or other suitable
means, or it may be determined from the changes in position of the
leveler as it moves.
It will also be understood that in any of the embodiments described
above, the location of tracking device 58 and target 56 can be
switched. In other words, target 56 can be a stationary target
positioned off of machine 20 at a known location while tracking
device 58 is positioned on board contouring machine 20. In this
alternate configuration, the necessity of transmitting by radio the
position information measured by tracking device 58 is eliminated
because tracking device 58 is already on board the contouring
machined. Tracking device 58 would be positioned on board
contouring machine 20 at any location where it would be able to
detect the movement of one end of contouring assembly 28 with
respect to target 56. In another variation, microprocessors 70, 72,
and 74 can also be located off board the vehicle in a separate
computer, if desired. In such a situation, only the pulse width
modulated signal of processor 74 is transmitted to machine 20,
along with the tilt control signal of processor 72.
In another embodiment (not shown), tracking device 58 and target 56
are replaced by a Global Positioning System (GPS) or Differential
Global Positioning System (DGPS). The GPS or DGPS receiver is
positioned either at the same location as target 56, or at any
other suitable location on right side 46 of contouring assembly 28.
The GPS or DGPS receiver detects its movement in three dimensions
as contouring assembly 28 is moved over the material to be
contoured. The three dimensional position information of the GPS or
DGPS receiver is communicated to tracking processor 70 and utilized
in the same manner the target 56 position information is
utilized.
In still another embodiment, the present invention is a kit for
retrofitting existing leveling or smoothing machines in order to
give them the capability of contouring three dimensionally curved
surfaces. The kit is preferably used with existing leveling
machines, such as that disclosed in U.S. Pat. No. 4,930,935. Such
existing leveling machines include a leveler assembly that is
controlled uniformly at both of its ends, thereby leveling only one
or two dimensionally curved surfaces. The existing machines
typically include a pair of laser sensors disposed at the ends of
the leveler assembly. A rotating laser beam is positioned at a
location remote from the leveling machine and at a designated
height. As the laser beam rotates, the laser defines a plane
located at a designated height above the surface to be smoothed.
The pair of sensors extend in a vertical direction and detect the
rotating laser beam. Based on where the laser beam impinges the
sensors, the height of the leveler with respect to the rotating
laser beam is determined. The height of the leveler is then
adjusted to correspond to the desired height of the surface to be
smoothed. The kit includes target 56 that can either be positioned
on the leveler assembly or remotely from the leveling machine. The
kit also includes tracking device 58 which is positioned at the
opposite location from target 56, i.e. either on the leveler
assembly or remote from it. A control system 67 (FIG. 5) is further
included with the kit to control the right and left sides of the
leveling assembly independently, thereby transforming the assembly
into a contouring assembly, such as contouring assembly 28. The
control system 67 also controls the pivot or tilt of the leveler as
explained above in the event the contouring assembly is pivotally
mounted. The control system can either control a pair of hydraulic
cylinders 52 and 54 based solely on the position of one or more
targets 56, or it can control cylinders 52 and 54 based on the
combination of the position of target 56 and the output of
proximity sensor 78. Proximity sensor 78 is also included in the
kit if one end of contouring assembly 28 is to follow a physical
form. If the leveling machine includes a leveler assembly with an
adjustable tilt or pitch, control system 67 can be programmed to
control the pitch of the level assembly based on the slope of the
surface to be smoothed.
The kit can also include other components when used to modify an
existing leveling machine to one of the alternative embodiments
described previously. For example, the kit may include a segmented
contouring assembly in which the height of each of the segments of
the assembly is individually adjustable, thereby allowing a greater
degree of three dimensional curvature to be contoured. Such a kit
for a segmented contouring assembly may also include additional
targets and tracking devices to be used to measure the position of
each of the segments. The position of each segment if fed into a
control system that controls each individual segment. In other
embodiments, the kit may include a pair of extendable wires that
are mounted at one end on the leveler assembly and attached at
their other ends to two separate reference points. Such a kit
further includes a pair of distance encoders that measure the
length of the wires and a pair of angle encoders that measure the
angles defined by the wires and the leveling assembly. A control
system is included that calculates the position of the leveler
assembly based on the length of the wires and adjusts the height of
the ends of the leveler independently, thereby allowing the
previously existing leveling machine to contour three dimensional
surfaces.
While the present invention has been described in terms of the
preferred embodiments depicted in the drawings and discussed in the
above specification, it will be understood by one skilled in the
art that the present invention is not limited to these particular
preferred embodiments, but includes any and all such modifications
that are within the spirit scope of the present invention as
defined in the appended claims.
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