Cycle planner for an earthmoving machine

A method for determining a series of work cycles for an earthmoving machine is disclosed. The method includes the steps of determining a plurality of parameters, modeling a volume of material to be moved, planning a series of work cycles to move the volume of material, and determining a level of productivity of the series of work cycles. The method also includes the steps of repeating the above steps a predetermined number of times and choosing an optimal series of work cycles to move the volume of material.

TECHNICAL FIELD 
This invention relates generally to a method for determining an optimal 
series of work cycles for an earthmoving machine and, more particularly, 
to a method for modeling a series of work cycles and responsively 
determining an optimal series of work cycles for the earthmoving machine. 
BACKGROUND ART 
Earthmoving machines, e.g., track-type tractors and the like, are 
frequently used to move earth from a first location to a second location. 
For example, track-type tractors may be used to move a volume of earth 
from a first location to expose a layer of ore for subsequent mining. The 
volume of earth may then be moved to a second location, where the ore has 
already been mined. This continual process is common in open pit mining 
operations, as only a relatively small area of ore is exposed at any given 
time. As a result, the earth that is moved is used to reclaim the portion 
of the land that has previously been mined. 
Mining sites such as the one described above must operate as efficiently as 
possible to save costs. Currently, the process of moving earth is 
performed by operators who are required to plan work cycles of the 
earthmoving machines based on experience and personal preference. It is 
difficult, if not impossible, for an operator of an earthmoving machine to 
determine the optimal series of work cycles to move a volume of earth that 
would result in the most cost efficient operation. 
The present invention is directed to overcoming one or more of the problems 
as set forth above. 
DISCLOSURE OF THE INVENTION 
In one aspect of the present invention a method for determining a series of 
work cycles for an earthmoving machine is disclosed. The method includes 
the steps of determining a plurality of parameters, modeling a volume of 
material to be moved, planning a series of work cycles to move the volume 
of material, and determining a level of productivity of the series of work 
cycles. The method also includes the steps of repeating the above steps a 
predetermined number of times and choosing an optimal series of work 
cycles to move the volume of material. 
In another aspect of the present invention a method for determining a 
series of work cycles for an earthmoving machine is disclosed. The method 
includes the steps of determining a plurality of parameters, modeling a 
volume of material to be moved, planning a first series of work cycles to 
move the volume of material, and determining a level of productivity of 
the first series of work cycles. The method also includes the steps of 
planning a second series of work cycles to move the volume of material, 
determining a level of productivity of the second series of work cycles, 
and choosing one of the first and second series of work cycles to move the 
volume of material. 
In yet another aspect of the present invention a method for modeling a 
volume of material to be moved by an earthmoving machine is disclosed. The 
method includes the steps of determining a volume of material to be moved, 
determining a series of segments of the volume of material, and 
determining a series of segment work cycles for each segment.

BEST MODE FOR CARRYING OUT THE INVENTION 
Referring to the drawings, and with particular reference to FIG. 1, a 
diagrammatic illustration of an earthmoving machine 100 is shown. The 
earthmoving machine 100 of FIG. 1 is depicted as a track-type tractor 102. 
However, other types of earthmoving machines, e.g., motor graders, wheel 
loaders, excavators, and the like, may benefit from use of the present 
invention. Preferably, the earthmoving machine 100 includes an earthmoving 
implement 104. As shown in FIG. 1, the track-type tractor 102 includes an 
earthmoving implement 104, which is depicted as a bulldozer blade. Other 
types of earthmoving implements may be used with the present invention, 
e.g., motor grader blades, buckets, scrapers. 
With reference to FIG. 2, a diagrammatic illustration of a work site 200 as 
embodied for use with one aspect of the present invention is shown. The 
work site 200 is shown as an open pit mining site. However, other work 
sites requiring material to be moved could benefit from the features of 
the present invention. In the open pit mining site illustrated in FIG. 2, 
material is moved from a first location 202 to a second location 204 to 
expose an ore seam 206, e.g., a coal seam, for mining. The second location 
204 previously contained material covering the ore seam 206, but was moved 
in the same manner as above to a third location (not shown). Open pit 
mining operations where volumes of material are repeatedly shifted to 
previously mined sections are commonly used in the mining industry. The 
movement of material exposes ore in relatively small areas, and the moved 
material is used to reclaim sections of land previously mined. 
Referring now to FIGS. 3 and 4, and in particular to FIG. 3, a volume of 
material 302 to be moved is shown. The volume of material 302 typically is 
created by loosening an area with explosives, resulting in a loose volume 
of material known as a blast pile. The volume of material 302 may then be 
moved to the second location 204 using earthmoving machines 100 such as 
track-type tractors 102. 
The volume of material 302 is shown divided into segments in FIG. 3. In 
FIG. 4, an illustration of a segment of material 304 is shown. The segment 
of material 304 is further divided up into segment work cycles 402. 
Preferably, each segment work cycle 402 represents an amount of material 
that an earthmoving machine l00 is capable of moving in one pass. 
In the preferred embodiment, each segment is determined based on an 
estimated amount of time required to move the segment, e.g., each segment 
may take one hour to move. The width, shape, and angle of each segment 
contributes to the estimated amount of time to move the segment. 
Preferably, the determination of each segment follows a set of constraints. 
For example, each segment is preferably created to allow downhill removal 
of material, the segments sequence from the top of the volume of material 
302 to the bottom of the volume of material 302, and each segment is 
created to be productive for moving material. 
Referring now to FIGS. 5-8, a sequence of steps illustrating an aspect of 
the present invention is shown. In FIG. 5, a first slice line 502 is drawn 
through the volume of material 302. The first slice line 502 defines a 
first segment of material to be moved 504. 
In FIG. 6, the first segment of material to be moved 504 has been moved and 
is depicted as a first segment of material moved 602. In FIG. 7, a second 
slice line 702 is drawn through the volume of material 302. The second 
slice line 702 defines a second segment of material to be moved 704. 
With reference to FIG. 8, the second segment of material to be moved 704 
has been moved and is now depicted as a second segment of material moved 
802. 
The steps shown in FIGS. 5-8 are repeated until the volume of material 302 
has been moved from the first location 202 to the second location 204, 
thus exposing the ore seam 206, as is shown in FIG. 2. 
Referring now to FIG. 9, a flowchart illustrating a preferred method of the 
present invention is shown. It is noted that the present invention relates 
to modeling the volume of material 302 to be moved, and planning a series 
of work cycles to simulate moving the volume of material 302. The steps 
are repeated with different series of work cycles to determine an optimal 
series of work cycles to move the volume of material 302. From these steps 
in simulation, the earthmoving machine 100 may then be controlled to move 
the volume of material 302 using the optimal series of work cycles. 
In a first control block 902 in FIG. 9, parameters of the earthmoving 
machine 100 and the volume of material 302 are determined. Parameters of 
the earthmoving machine l00 may include, but are not limited to, the size 
of the earthmoving machine 100, the size of the earthmoving implement 104, 
and the earthmoving capabilities of the earthmoving machine 100, e.g., an 
available power output of the earthmoving machine 100. Parameters of the 
volume of material 302 may include, but are not limited to, the 
composition of the material to be moved, e.g., sand, clay, rock; and the 
amount of moisture contained in the material. In addition, other 
parameters, such as the operator's visibility, may be determined. 
In a second control block 904, the volume of material 302 to be moved is 
modeled. In the preferred embodiment, the modeled volume of material 302 
is determined from a knowledge of the terrain from GPS, and from basic 
assumptions of the typical size of an area created as a blast pile. 
In a third control block 906, a series of work cycles is planned that would 
move the volume of material. In the preferred embodiment, the series of 
work cycles is an accumulation of the segment work cycles for the segments 
of the volume of material 302. The series of work cycles also includes an 
order in which the segment work cycles would be performed. 
Referring to FIG. 11, a flowchart illustrating a preferred method for 
planning a series of work cycles is shown. In a first control block 1102, 
the volume of material 302 to be moved is determined. In a second control 
block 1104, a series of segments of the volume of material 302 is 
determined. In a third control block 1106, a series of segment work cycles 
for each segment is determined as a function of the parameters of the 
earthmoving machine 100 and the volume of material 302. The determination 
of the series of segments and the series of segment work cycles is 
discussed above in greater detail with reference to FIGS. 3 and 4. 
Referring back to FIG. 9, in a fourth control block 908, a level of 
productivity of the series of work cycles is determined as a function of a 
predetermined optimization parameter. Preferably, a clock is initialized 
to zero prior to simulated earthmoving, and the predetermined optimization 
parameter is a function of time. However, the level of productivity could 
be a function of some other optimization parameter, such as work 
performed, machine wear, or fuel usage. 
In a first decision block 910, a determination is made to plan another 
series of work cycles. If the determination is yes, the volume of material 
302 is modeled with a new series of segments and a new series of segment 
work cycles. The new segments are determined by changing the width and the 
angle of each current segment within constraints. A new series of work 
cycles is planned which would move the volume of material 302. The level 
of productivity for the new series of work cycles is determined. The 
process is repeated a predetermined number of times, with a level of 
productivity being determined for each planned series of work cycles. 
In one embodiment, the number of times for repeating the above steps is 
determined in response to the level of productivity of the most current 
planned series of work cycles approaching the predetermined optimization 
parameter in value. In another embodiment, the number of times for 
repeating the above steps is determined in response to the difference in 
the level of productivity of the most current planned series of work 
cycles compared to the level of productivity of a previous planned series 
of work cycles being less than a predetermined threshold. Other 
embodiments for determining the number of times for repeating the above 
steps could be used without deviating from the spirit of the present 
invention. 
If the decision is made in the first decision block 910 not to plan another 
series of work cycles, control then proceeds to a fifth control block 912. 
In the fifth control block 912, the optimal series of work cycles for the 
earthmoving machine 100 to move the volume of material 302 is chosen. The 
chosen series of work cycles may then be used to control the earthmoving 
machine 100 to move the volume of material 302. In one embodiment, 
operator guidance is provided to allow better manual control of the 
earthmoving machine 100. In another embodiment, the earthmoving machine 
100 is controlled to operate autonomously. 
Referring now to FIG. 10, a flowchart illustrating an alternate embodiment 
of the present invention is shown. 
In a first control block 1002, parameters of the earthmoving machine 100 
and the volume of material 302 are determined. In a second control block 
1004, the volume of material 302 is modeled. In a third control block 
1006, a first series of work cycles to move the volume of material 302 is 
planned. In a fourth control block 1008, the level of productivity of the 
first series of work cycles is determined. 
Control then proceeds to a fifth control block 1010, where a second series 
of work cycles to move the volume of material 302 is planned. In a sixth 
control block 1012, the level of productivity of the second series of work 
cycles is determined. In a seventh control block 1014, one of the first 
and second series of work cycles is chosen as being the most optimal 
series of work cycles, i.e., having a higher level of productivity. 
It is understood that this embodiment may be extended to a third planned 
series of work cycles, or a fourth, or any desired number of series of 
work cycles without deviating from the spirit of the invention, as long as 
one series of work cycles is chosen as having a higher level of 
productivity than the other series of work cycles. 
Industrial Applicability 
The present invention provides a method to model and simulate multiple 
series of work cycles used to move a volume of material from a first 
location to a second location to determine an optimal series of work 
cycles to perform the task. The modeling and simulation may be performed 
by a processor located on board the earthmoving machine 100, or may be 
performed by a processor located at a remote site, such as at a site 
office. Once the present invention has determined the optimal series of 
work cycles, the earthmoving machine 100 may be controlled to perform the 
desired work cycles to move the material. 
Other aspects, objects, and features of the present invention can be 
obtained from a study of the drawings, the disclosure, and the appended 
claims.