The current disclosure relates to systems for controlling machines operating at a worksite and, more particularly, relates to a control system and a method for controlling an earthmoving machine operating at the worksite.
Worksites, such as mine sites, landfills, and construction sites, undergo topographical transformation by machines and/or workers performing various tasks thereat. Machines, such as dozers, excavators, motor graders, and wheel loaders, are deployed at the worksite to perform a mission. The mission can include digging, grading, and leveling, for altering a terrain at the worksite, based on an excavation plan.
The machines can be operated autonomously or semi-autonomously to execute the mission. While operating in the autonomous or the semi-autonomous manner, it is desired to minimize or eliminate need of an operator's intervention. Commands generated for moving the machines and their associated work implements are often generated by a planning system. However, multiple parameters are required to be considered and/or set prior to creation and implementation of such excavation plans, which otherwise may affect command generation and impact operation efficiency of the machines. A small error during consideration of the parameters may render the excavation plan invalid or unacceptable and may impact overall efficiency of the machines.
In one aspect of the current disclosure, a control system for controlling an earthmoving machine operating at a worksite is provided. The control system includes a receiving unit configured to receive a first input indicative of a terrain profile of the worksite, a second input indicative of a target terrain profile for the worksite, and a third input indicative of characteristics of the earthmoving machine. The control system further includes a mission planning controller in communication with the receiving unit. The mission planning controller is configured to generate an excavation plan based on the first input, the second input, and the third input. The mission planning controller is further configured to control operation of the earthmoving machine, based on the generated excavation plan, to obtain an excavated terrain profile. The mission planning controller is further configured to determine whether the excavated terrain profile matches with the target terrain profile, and operate the earthmoving machine, based on inputs indicative of the excavated terrain profile, the second input, the third input, and an extent of match between the excavated terrain profile and the target terrain profile.
In another aspect of the current disclosure, a method for controlling an earthmoving machine operating at a worksite is provided. The method includes receiving a first input indicative of a terrain profile of the worksite, receiving a second input indicative of a target terrain profile for the worksite, and receiving a third input indicative of characteristics of the earthmoving machine. The method further includes generating an excavation plan based on the first input, the second input, and the third input. The method further includes controlling operation of the earthmoving machine, based on the generated excavation plan, to obtain an excavated terrain profile. The method further includes determining whether the excavated terrain profile matches with the target terrain profile, and operating the earthmoving machine, based on inputs indicative of the excavated terrain profile, the second input, the third input, and an extent of match between the excavated terrain profile and the target terrain profile.
In yet another aspect of the current disclosure, an earthmoving machine is provided. The earthmoving machine includes a work implement for engaging ground surface of a worksite and a control system for operating the earthmoving machine. The control system includes a mission planning controller configured to receive a first input indicative of a terrain profile of the worksite, a second input indicative of a target terrain profile for the worksite, and a third input indicative of characteristics of the earthmoving machine. The mission planning controller is further configured to generate an excavation plan based on the first input, the second input, and the third input. The mission planning controller is further configured to adjust the work implement, based on the generated excavation plan, to obtain an excavated terrain profile. The mission planning controller is further configured to determine whether the excavated terrain profile matches with the target terrain profile, and operate the earthmoving machine, based on inputs indicative of the excavated terrain profile, the second input, the third input, and an extent of match between the excavated terrain profile and the target terrain profile.
Other features and aspects of this disclosure will be apparent from the following description and the accompanying drawings.
The operator station 106 may be located proximal to the worksite 100 or may be located remotely from the worksite 100. The operator station 106 may include data repository (not shown) having details including, but not limited to, terrain information of the worksite 100, number of active machines at the worksite 100, characteristics of the machines 102. The operator station 106 may further be equipped with multiple devices capable of receiving data, processing the data, and communicating the processed data via communication channels 108 to the machines 102.
The operator station 106 further includes a control system 110, hereinafter referred to as the system 110. The system 110 is configured to be in communication with the multiple devices located at the operator station 106, the machines 102 located at the worksite 100, and a perception unit 302. The system 110 is configured to control operation of the machines 102 based on the processed data from the multiple devices, and inputs received from the operator and the perception unit 302.
The perception unit 302 is configured to capture the terrain profile 104 of the worksite 100. The terrain profile 104 may include terrain data, such as elevation, material type, material properties, slip coefficient, and other data of the terrain profile 104. In an example, the perception unit 302 may be embodied as an aerial unit, such as a drone, to perform an automated survey of the worksite 100. For such purpose, the perception unit 302 may be equipped with survey systems, such as stereo photography cameras, or LASER, or RADAR, to capture the terrain profile 104 of the worksite 100. It may be understood here that the perception unit 302 captures the terrain profile 104 through stereo photos or through multiple frames which may constitute a video as well. Since the perception unit 302 can be embodied as devices capable of being disposed aerially above the worksite 100, the perception unit 302 is illustrated outside the operator station 106. In another example, the perception unit 302 may either be mounted on the operator station 106 or at an appropriate location in the worksite 100, where the perception unit 302 is capable of capturing the terrain profile 104 of the worksite 100 from a distance.
The machine 102 further includes a cab 220 having multiple input devices (not shown). The multiple input devices are configured to receive operational commands from either the operator station 106 or a remote control device (not shown), to control operation of the machine 102 and operate the work implement 202 of the machine 102. The machine 102 can be operated either autonomously or semi-autonomously. When the machine is operated in semi-autonomous manner, the machine 102 can be controlled by the remote control device present at the operator station 106 or by an operator using the remote control device at the worksite 100. When operating autonomously, operational commands are communicated to the machine 102 from the operator station 106 or from the remote control device (not shown) through wireless communication. On receipt of such operational commands, the machine 102 executes operations based on the received operational commands.
The perception unit 302 is configured to be in communication with a receiving unit 304 and capture the terrain profile 104 of the worksite 100. Upon capturing the terrain profile 104, the perception unit 302 is configured to generate a first input ‘I-1’.
The receiving unit 304 in communication with the perception unit 302 is configured to receive a first input ‘I-1’ indicative of the terrain profile 104 of the worksite 100. In one embodiment, the communication between the perception unit 302 and the receiving unit 304 may be established through the network 301. In another embodiment, a separate communication channel may be provided for the communication between the perception unit 302 and the receiving unit 304. The receiving unit 304 is further configured to be in communication with a user interface 306 of the system 110.
In one embodiment, the user interface 306 may include devices, including but not limited to, a computer device having a display. The user interface 306 enables a user or the operator to feed a target terrain profile (indicated by reference numeral 408 in
The target terrain profile may be designed based on a requirement by the operator and/or the customer. Additionally, the target terrain profile may be designed based on a current terrain at the worksite 100. Factors such as type of constituent material and distribution of the constituent material in the worksite 100 may also be considered while designing the target terrain profile. For the purpose of this description, data pertaining to the target terrain profile is considered as a second input ‘I-2’. Accordingly, the receiving unit 304 is configured to receive the second input ‘I-2’ indicative of the target terrain profile. The receiving unit 304 of the system 110 is further configured to be in communication with the machine 110 operating at the worksite 100.
The system 110 is located in the operator station 106 and is configured to be in communication with the machine 102 through the network 301 and the communication channels 108, for controlling the operation of the machine 102. In an example, the network 301 may be a wireless network.
The receiving unit 304 is further configured to receive a third input ‘I-3’ indicative of characteristics of the machine 102. The characteristics of the machine 102 may be available at the data repository located at the operator station 106 or a central server (not shown) present at a remote location. The characteristics of the machine 102 may include, but not limited to, width ‘W’ (as shown in
The system 110 further includes a mission planning controller 310, hereinafter referred to as the controller 310. The term “controller” is meant to be used in its broadest sense to include one or more controllers and/or microprocessors that may be associated with the machine 102 and that may cooperate in controlling various functions and operations of the machine 102.
In some examples, the controller 310 may be a processor that may include a single processing unit or a number of processing units, all of which include multiple computing units. The explicit use of the term ‘processor’ should not be construed to refer to software and/or hardware capable of executing a software application. Rather, the controller 310 may be implemented as one or more microprocessors, microcomputers, digital signal processors, central processing units, state machine, logic circuitries, and/or any device capable of manipulating signals based on operational instructions. Among the capabilities mentioned herein, the controller 310 may also be configured to receive, transmit, and execute computer-readable instructions. For example, the controller 310 may operate in a logical fashion to perform desired operations, execute control algorithms, store and process images.
In some embodiments, the controller 310 may be embodied as non-transitory computer readable medium. In an example, the non-transitory computer readable medium may include a memory, such as RAM, ROM, a flash memory, and a hard drive, and/or a data repository integrated therein. The computer readable medium may also be configured to store electronic data associated with operation of the machine 102.
In the current disclosure, the controller 310 is communicatively coupled with the receiving unit 304 and is configured to generate an excavation plan (indicated by reference numeral 414 in
Based on the generated excavation plan, the controller 310 is configured to control operation of the machine 102 to obtain an excavated terrain profile (indicated by reference numeral 424 in
Upon execution of each excavation plan, the perception unit 302 captures the excavated terrain profile and generates inputs indicative of the excavated terrain profile. Subsequently, the receiving unit 304 may receive real-time inputs, from the perception unit 302, indicative of the excavated terrain profile. Further, the controller 310 is configured to determine whether the excavated terrain profile matches with the target terrain profile. The manner in which the controller 310 compares the excavated terrain profile and the target terrain profile is described with respect to
In cases where the controller 310 determines that the excavated terrain profile matches with the target terrain profile, the controller 310 may stop controlling the operation of the machine 102. In an example, the controller 310 may notify the operator that the target terrain profile is achieved. However, in cases where the controller 310 determines that the excavated terrain profile is not matching with the target terrain profile, the controller 310 is configured to generate additional excavation plans. The machine 102 may then be operated by the controller 310, to execute the additional excavation plans, based on inputs indicative of the excavated terrain profile, the second input ‘I-2’, the third input ‘I-3’, and an extent of match between the excavated terrain profile and the target terrain profile.
Further, the controller 310 generates the superimposed diagram 410 based on the first two-dimensional diagram 404 and the second two-dimensional diagram 406, as shown in
As described earlier, the controller 310 generates the excavation plan 414, based on the terrain profile 104, the target terrain profile 408, and the characteristics of the machine 102. The excavation plan 414 includes multiple nodes and multiple segments, where each segment connects two consecutive nodes and is indicative of an excavation path for the machine 102. Among the multiple nodes, a first node 416 is defined at a beginning of a predefined portion, such as the exemplary portion 402, of the worksite 100 and at the predetermined depth ‘X’ from the terrain profile 104, based on the characteristics of the machine 102 and the target terrain profile 408. A second node 418 of the multiple nodes is defined at a point of intersection of the target terrain profile 408 and a locus of the first node 416 tracing a path spaced apart at the predetermined depth ‘X’ along the terrain profile 104. In case the second node 418 cannot be defined based on the locus of the first node 416 mentioned hereinabove, the second node 418 is defined at a point of intersection of the target terrain profile 408 and an inclined line extending from the first node 416. The inclined line is associated with a predetermined slope. In an example, the predetermined slope for the inclined line may be determined based on the terrain profile 104. For instance, the predetermined slope may vary based on elevation of the terrain profile 104 with respect to a horizontal ground surface at the worksite 100. In an aspect of the current disclosure, minimum number of nodes in the excavation plan 414 may be two for the uneven surface. In case the terrain profile 104 includes elevations and pits, the number of nodes may increase to three or four based on complexity of the terrain profile 104 and the target terrain profile 408.
Generation of the excavation plan 414 with respect to
Considering that the machine 102 will be deployed at the beginning of the exemplary portion 402 of the worksite 100, the controller 310 generates the excavation plan 414 based on the terrain of the three segments, the target terrain profile 408, and the characteristics of the machine 102. Based on the generated two-dimensional diagram of the terrain profile 104 in first segment ‘S1’, the first node 416 of the excavation plan 414 is defined at the beginning of the exemplary portion 402 and at the predetermined depth ‘X’ from the terrain profile 412. In an example, the predetermined depth ‘X’ from the terrain profile 412 may be set to at least 50 percent of the width ‘W’ of the work implement 202 of the machine 102. However, the predetermined depth ‘X’ may be selected from a range, for example, between 30 percent and 75 percent. The first node 416 is displayed on the superimposed diagram 410 already present on the user interface 306.
For the purpose of defining the second node 418 of the excavation plan 414, the controller 310 may plot a locus of the first node 416, such that the locus is spaced at a distance equal to the predetermined depth ‘X’ along the terrain profile 104. At a point where the locus intersects the target terrain profile 408, the second node 418 is defined. In cases where such locus condition does not yield an intersection point between the terrain profile 104 and the target terrain profile 408, the controller 310 may plot an inclined line extending from the first node 416 and intersecting the target terrain profile 408. The inclined line may be associated with a predetermined slope. In one example, the predetermined slope may be 20 percent. However, for some exemplary portions of the worksite 100 where the above two ways of defining the second node 418 does not hold good, the controller 310 may define the second node 418 at an end of such exemplary portion of the worksite 100. Further, the controller 310 plots a first line segment 422 between the first node 416 and the second node 418. The first line segment 422 indicates the excavation path for the machine 102 in the segment-1.
In order to have the excavation plan 414 executed by the machine 102, the controller 310 communicates operational commands to the machine 102 through the communication channel 108. For example, the controller 310 may communicate the operational commands to an electronic control module (ECM) of the machine 102. In one embodiment, the operational commands may include adjusting penetration of the work implement 202 into the terrain profile 104 at the beginning of the exemplary portion 402. For instance, the penetration of the work implement 202 may be set to 50 percent of the width ‘W’ of the work implement 202. That is, the work implement 202 may be penetrated to half width into the terrain profile 104. In an embodiment, adjusting the penetration of the work implement 202 into the terrain profile 104 may be based on type of constituent material in the first segment ‘S1’. For instance, the predetermined depth ‘X’ from the terrain profile 104 may be set to 30 percent when constituent material in first segment ‘S1’ is hard. Besides operational commands for adjusting penetration of the work implement 202, operational commands concerning movement of the machine 102 may also be communicated by the controller 310.
Additionally, based on the inclination of the terrain profile 104 of first segment ‘S1’, operational commands for controlling movement of the machine 102 may also be communicated. That is, the operational commands may also include setting speed of the machine 102 travelling along the inclined terrain profile in the first segment ‘S1’. Accordingly, the controller 310 controls the operation of the machine 102 until the machine 102 reaches the second node 418, to obtain the excavated terrain profile 424 (see
In operation, the machine 102 moves material present along the excavation path and travels until a front end of the tracks 210 of the machine 102 reaches the third node 502, thereby obtaining the excavated terrain profile 424. Upon reaching the third node 502, the material is dumped into pit 506 to form a first dump 508. Thereafter, the operational commands received from the controller 310 may cause the machine 102 to retrace the excavation path in a reverse direction until the machine 102 reaches the beginning of the exemplary portion 402 of the worksite 100.
During the excavation operation of the machine 102 along the excavation path, the perception unit 302 captures the excavated terrain profile 424 and generates inputs indicative of the excavated terrain profile 424. The receiving unit 304 of the system 110 receives real-time inputs indicative of the excavated terrain profile 424. Owing to the communication between the controller 310 and the receiving unit 304, the controller 310 determines whether the excavated terrain profile 424 matches with the target terrain profile 408. In an example, the matching of the excavated terrain profile 424 and the target terrain profile 408 may be performed by comparing two-dimensional diagram of the excavated terrain profile 424 with that of the target terrain profile 408. When the excavated terrain profile 424 is not matching with the target terrain profile 408, the controller 310 is configured to generate additional excavation plans 510, 512, and 514 (as shown in
Due to the first dump 508, terrain of the second segment ‘S2’ extends by a distance corresponding to a width of the first dump 508. The controller 310 then defines the third node 502 at a point on the excavated terrain profile 424, such that the third node 502 is located at a maximum travel point which is not lower than the second node 418. As the machine 102 executes each of the excavation plans 510, 512, and 514 along respective excavation paths, the first node 416 and the third node 502 get re-defined. As such, the machine 102 travels longer distance until it reaches the third node 502, thereby filing the pit 506 with additional dump of material, such as a second dump 518, a third dump 520, and so on, until the pit 506 is filled and the machine 102 encounters a wall 524. It will be understood that the material dumped into the pit 506 may be loose soil, and movement of the machine 102 over such loose soil may cause compactness of the soil in the pit 506. Any decrease in level of the material in the pit 506 due to movement of the machine 102 thereon may be compensated by dumping additional material into the pit 506 to achieve a flat terrain.
In case material is left over in segment-1 as overburden even after filling the pit 506, the controller 310 operates the machine 102 by generating further excavation plans. The machine 102 moves material from segment-1 and over segment-2 until the wall 524 is encountered. Since the machine 102 has reached a maximum travel path, the controller 310 controls the machine 102 to dump the material at the wall 524, where such dumping forms a heap 526. By executing such operation repeatedly, the machine 102 may be able to back stack multiple heaps as shown in
Referring to
Referring to
For the illustration purpose of the current disclosure, an area of the second exemplary portion 616 defined at the left of the pivot point 626 is referred to as the cut zone and an area of the second exemplary portion 616 at the right of the pivot point 626 is referred to as the fill zone. Thus, the pivot point 626 may be configured to define the cut zone and the fill zone at the worksite 100. The controller 310 may communicates the operational commands to the machine 102 via the communication channel 108 to perform the excavation operations in the cut zone until the material is removed therefrom to achieve the target terrain profile 618. Referring to the first and second exemplary portions 602, 616 described in
Referring to
Similarly, in the fill zone, the excavation plan 624 may be defined based on elevation of each successive point with respect to the target terrain profile 618. Specifically, the elevation of each successive point may be determined based on the target terrain profile 618 to be achieved and the operator's desire. In the illustrated aspect of the current disclosure, an empirical relation to determine the excavation plan 624 in the fill zone may be: Excavation Plan=min (target terrain profile, Operator's desire). In other aspects of the current disclosure, the excavation plan 624 may be determined based on various mathematical and/or empirical relations between the terrain profile 104, the target terrain profile 618, and the operational characteristics of the machine 102. Thus, the controller 310 may be configured to generate the excavation plan 624 in the cut zone and the fill zone based on the target terrain profile 618 and the operator's desire. The excavation plan 610 for the first exemplary portion 602 may also be generated based on the empirical relations as described above.
The excavation plan 624 may also be determined based on certain criteria that design of the excavation plan 624 have to be limited in such a way that the excavation plan 624 does not go below the target terrain profile 618 in the cut zone and does not go above the target terrain profile 618 in the fill zone. Also, as the material is required to be removed from the cut zone, the work implement 202 of the machine 102 is adjusted in such a way that the work implement 202 does not go below the target terrain profile, and hence any potential damage to coal layer may be avoided. Whereas, in the fill zone, as the material required to be dumped, the machine 102 may pile the material in dump locations of the fill zone on a slope not exceeding the predefined slope of the target terrain profile 618. Such that the machine 102 and other earthmoving equipment may climb and modify the piled material to achieve the target terrain profile 618.
Referring to
The system 110 of
The second input ‘I-2’ may be received from the operator station 106 through the communication channel 108 and the network 301. Further, characteristics of the machine 102 may be stored in a memory (not shown) of the controller 310. As such, the controller 310 may receive or retrieve the characteristics of the machine 102 from the memory.
The controller 310 is further configured to generate the excavation plan 414 based on the first input ‘I-1’, the second input ‘I-2’, and the third input ‘I-3’. Based on the generated excavation plan 414, the controller 310 is configured to adjust the work implement 202 and control movement of the machine 102 along the terrain profile 104 to obtain the excavated terrain profile 424. Since the perception unit 302 captures the excavated terrain profile 424 upon execution of each excavation plan 414, the perception unit 302 generates inputs indicative of the excavated terrain profile 424 as well. Owing to the connection between the controller 310 and the perception unit 302, the controller 310 receives real-time inputs, from the perception unit 302, indicative of the excavated terrain profile 424.
On receipt of such real-time inputs from the perception unit 302, the controller 310 is configured to determine whether the excavated terrain profile 424 matched with the target terrain profile 408. Further, the controller 310 generates operational commands to operate the machine 102 based on the inputs indicative of the excavated terrain profile 424, the second input ‘I-2’, the third input ‘I-3’, and an extent of match between the excavated terrain profile 424 and the target terrain profile 408.
In one embodiment, the machine 102 equipped with the system 110 may be considered as a master machine and multiple other machines operating simultaneously at the worksite 100 may be controlled by the system 110 of the master machine. For example, the master machine may generate excavation plans for other machines operating at the worksite 100. Since the machine 102 is in communication with the operator station 106, the operator at the operator station 106 may be notified regarding extent of completion of the excavation plans by each machine operating at the worksite 100.
The current disclosure relates to the system 110 and a method 800 for controlling the machine 102 operating at the worksite 100.
Various steps of the method 800 are described in conjunction with
At step 804, the method 800 includes receiving the second input ‘I-2’ indicative of the target terrain profile 408 for the worksite 100. The target terrain profile 408 may be indicative of a desired terrain at the worksite 100. Data pertaining to the target terrain profile 408 may be fed into the system 110. At step 806, the method 800 includes receiving the third input ‘I-3’ indicative of characteristics of the machine 102. In one example, the characteristics of the machine 102 may include, but not limited to, the width ‘W’ of the work implement 202 of the machine 102, length of the work implement 202 of the machine 102, width of the machine 102.
At step 808, the method 800 includes generating the excavation plan 414 based on the first input ‘I-1’, the second input ‘I-2’, and the third input ‘I-3’. The excavation plan 414 includes multiple nodes and multiple segments, where each segment connects two consecutive nodes. Each segment indicates the excavation path for the machine 102 executing the excavation plan 414. Since the generated excavation plan 414 is based on automatically gathered inputs, manual consideration of parameters for the purpose of generating the excavation plan 414 is eliminated.
At step 810, the method 800 includes controlling the operation of the machine 102 based on the excavation plan 414 to obtain the excavated terrain profile 424. In one embodiment, the method 800 may include generating operational commands, by the controller 310, and communicating the generated operational commands, via the communication channel 108, to the machine 102. In one example, the operational commands may include adjusting penetration of the work implement 202 of the machine 102 into the terrain profile 104. In another example, the operational command may also include setting of speed of movement of the machine 102 along the excavation path.
At step 812, the method 800 includes determining whether the excavated terrain profile 424 matches with the target terrain profile 408. At step 814, the method 800 includes operating the machine 102, based on inputs indicative of the excavated terrain profile 424, the second input ‘I-2’, the third input ‘I-3’, and an extent of match between the excavated terrain profile 424 and the target terrain profile 408.
Although not explicitly covered as steps in
Thus, the system 110 and the method 800 of the current disclosure provide an efficient way to generate excavation plans for earthmoving machines 102 operating at the worksite 100. Additionally, since the excavation plans are generated by the system 110, requirement of large number of workers at the operator station 106 may be avoided, thereby minimizing operational cost of generating excavation plans. Further, efficiency of executing the excavation plan 414 correctly may be increased which was otherwise low in present day planning systems.
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Number | Date | Country | |
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20190055715 A1 | Feb 2019 | US |