Work machine control device

Abstract

To provide a control device of a work machine capable of planning a transporting route of the work machine excellent in efficiency and followability.SOLUTION: A control device of a work machine creates a plurality of route candidates of a transporting route TR without including a route of which curvature radius is smaller than a minimum turning radius of the work machine based on the basis of position information (x1,y1), (x2,y2) on a loading position LP and an unloading position DP, and a loading direction θ1 of the work machine at the loading position LP, and an unloading direction θ2 of the work machine at the unloading position DP. Further, the control device of the work machine calculates an evaluation value of each of route candidates based on at least the route length, the radius, or the number of turning positions of each of the plurality of the route candidates, and selects a route candidate highest in evaluation value from among the plurality of route candidates as the transporting route TR.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present disclosure relates to a control device for a work machine. [Background technology]

[0002] Conventionally, there have been known work control devices for loading and transporting vehicles. For example, Patent Document 1 below discloses a work control device for a loading and transporting vehicle that repeatedly performs one cycle of loading and transporting work, in which the vehicle loads a load at a loading position in a loading dock, returns to a dumping dock via a turning point, unloads the load at the dumping dock, and then moves from the dumping dock to the loading dock again via the turning point (paragraph 0008, claim 1, etc. of the same document).

[0003] The conventional work control device for a loading and transporting vehicle comprises input means, calculation means, and control means. The input means inputs teaching data for the vehicle positions and vehicle attitude angles at the loading site, the turning point, and the dumping site. The calculation means calculates the positions of each point on a planned travel route connecting the loading site, the turning point, and the dumping site based on the teaching data input by the input means. The control means controls the loading and transporting vehicle so that it moves along each point on the planned travel route calculated by the calculation means and performs the loading and transporting work. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 10-212035 Summary of the Invention [Problem to be solved by the invention]

[0005] As described above, the conventional work control device for a loading and transporting vehicle requires input of teaching data for the vehicle position and vehicle attitude angle at each of the loading site, the turning point, and the unloading site to the input means. Therefore, depending on the content of the teaching data input to the input means, it may not be possible to plan an efficient route for the loading and transporting vehicle. For example, if teaching data for the vehicle position is set inside the minimum turning radius of the loading and transporting vehicle or in a blind spot of an obstacle, an inefficient route including many turning points may be planned, or the loading and transporting vehicle may not be able to track the vehicle position or vehicle attitude angle.

[0006] The present disclosure provides a control device for a work machine that is capable of planning an efficient and highly responsive transport route for the work machine. [Means for solving the problem]

[0007] One aspect of the present disclosure is a control device for a work machine that plans a transport route in which a load is loaded at a loading position, reversing from the loading position to a turning position, and moving forward from the turning position to unload the load at a loading / unloading position, the control device for a work machine is characterized in that it generates multiple route candidates for the transport route that do not include a route with a radius of curvature smaller than the minimum turning radius of the work machine based on position information of the loading position and the loading / unloading position, the loading orientation of the work machine at the loading position, and the loading / unloading orientation of the work machine at the unloading position, calculates an evaluation value for each of the multiple route candidates based on at least one of the route length, curvature, or number of turning positions of the each of the multiple route candidates, and selects the route candidate with the highest evaluation value from the multiple route candidates as the transport route. [Effects of the Invention]

[0008] According to the above aspect of the present disclosure, it is possible to provide a control device for a work machine that is capable of planning an efficient and highly responsive transport route for the work machine. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a perspective view of a work machine illustrating a first embodiment of a control device for a work machine according to the present disclosure. [Figure 2] FIG. 2 is a block diagram showing a schematic configuration of the work machine of FIG. 1. [Figure 3] FIG. 3 is a block diagram of an automatic driving control device included in the control device of the work machine of FIG. 2. [Figure 4] An example of map information recorded in the automatic driving control device of Figure 3. [Figure 5] An example of a work instruction input to the automatic driving control device in Figure 3. [Figure 6] FIG. 4 is a flowchart showing the processing flow of a route planning unit of the automatic driving control device of FIG. 3. [Figure 7] 7 is an example of a transportation route generated by the processing of FIG. 6. [Figure 8] 7 is an example of a route candidate generated by the process of generating route candidates in FIG. 6. [Figure 9] 9 is a graph showing the curvature of the candidate paths in FIG. 8; [Figure 10] FIG. 7 is a flowchart showing details of the process of selecting a transportation route in FIG. 6. [Figure 11] 10 is an example of a loading position in a second embodiment of a control device for a work machine according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of a control device for a work machine according to the present disclosure will be described with reference to the drawings.

[0011] [Embodiment 1] Fig. 1 is a perspective view of a work machine 100 illustrating a first embodiment of a control device for a work machine according to the present disclosure. Fig. 2 is a block diagram showing a schematic configuration of the work machine 100 of Fig. 1.

[0012] Although details will be described later, the construction machine control device 200 of this embodiment is configured to be mounted on, for example, the construction machine 100, and to control the operation of each part of the construction machine 100 so as to enable automatic operation of the construction machine 100. The construction machine 100 is, for example, a wheel loader. Note that the construction machine 100 is not limited to a wheel loader, and may be, for example, another construction machine capable of transporting a load, such as a rigid dump truck or a hydraulic excavator.

[0013] The work machine 100 is equipped with, for example, a front body 101F, a rear body 101R, a center joint 101C, a pair of front wheels 102F, and a pair of rear wheels 102R. The work machine 100 is also equipped with an engine 103, a power transmission mechanism 104, a front differential 105F, a rear differential 105R, a front wheel brake 106F, and a rear wheel brake 106R. The work machine 100 is also equipped with, for example, a lift arm 107, a bucket 108, and a hydraulic unit 110. The work machine 100 is also equipped with, for example, a user interface 121, a positioning device 122, and a work machine control device 200.

[0014] The front body 101F and the rear body 101R are connected via a center joint 101C, for example, so that they are rotatably connected to each other about a rotation axis that is parallel to the height direction of the work machine 100. A pair of front wheels 102F and a pair of rear wheels 102R are provided on the front body 101F and the rear body 101R, respectively. The engine 103 generates power by rotating under the control of, for example, a control device 200 of the work machine.

[0015] The power transmission mechanism 104 transmits, for example, the power of the engine 103 to a front differential 105F and a rear differential 105R. The front differential 105F and the rear differential 105R transmit the power transmitted from the engine 103 via the power transmission mechanism 104 to a pair of front wheels 102F and a pair of rear wheels 102R, respectively. This causes the pair of front wheels 102F and the pair of rear wheels 102R to rotate, allowing the work machine 100 to travel.

[0016] The lift arm 107 has, for example, a pair of left and right arm sections that extend from the front body section 101F towards the front of the work machine 100, and a connecting section that connects the pair of arm sections at the longitudinal center. One longitudinal end of the lift arm 107 is attached to the upper part of the front body section 101F via a rotation shaft that is parallel to the width direction of the work machine 100. As a result, the lift arm 107 is provided so as to be able to rotate up and down around the rotation shaft attached to the upper part of the front body section 101F.

[0017] A bucket 108 is attached to the other longitudinal end of the lift arm 107 via a rotation shaft that is parallel to the width direction of the work machine 100. As a result, the bucket 108 is provided so as to be rotatable up and down about the rotation shaft that is attached to the tip of the lift arm 107 on the side opposite to the one longitudinal end that is connected to the front body part 101F.

[0018] The hydraulic device 110 includes, for example, a hydraulic pump 111, a control valve 112, a pair of steering cylinders 113, a pair of lift cylinders 114, and a bucket cylinder 115. The hydraulic pump 111 is driven, for example, by the engine 103, and pumps hydraulic oil to the control valve 112 to generate hydraulic pressure.

[0019] The control valve 112 is controlled, for example, by the work machine control device 200, and supplies the hydraulic pressure of the hydraulic oil pumped from the hydraulic pump 111 to the front wheel brake 106F and the rear wheel brake 106R. This operates the front wheel brake 106F and the rear wheel brake 106R, braking the pair of front wheels 102F and the pair of rear wheels 102R, and enabling the work machine 100 to slow down or stop.

[0020] Furthermore, the control valve 112 is controlled, for example, by the work machine control device 200, and supplies hydraulic oil pumped from the hydraulic pump 111 to one of the pair of steering cylinders 113. As a result, one of the pair of steering cylinders 113 extends and the other of the pair of steering cylinders 113 contracts. As a result, the front body 101F turns right or left relative to the rear body 101R, centered on the center joint 101C.

[0021] This creates an angular difference between the front body 101F and the rear body 101R, making it possible to turn the work machine 100 to the right or left. In other words, the work machine 100 is equipped with an articulated steering mechanism, and turns by rotating the front body 101F relative to the rear body 101R about a rotation axis that is parallel to the height direction of the work machine 100.

[0022] Furthermore, the control valve 112 is controlled by, for example, the work machine control device 200, and distributes hydraulic oil pumped from the hydraulic pump 111 to a pair of lift cylinders 114 and a bucket cylinder 115. This causes the bucket cylinder 115 to extend, and the bucket 108 can be rotated upward via a bell crank attached to the connecting portion of the lift arm 107. As a result, the bucket 108 can scoop up a load such as soil and sand, crushed stone, or minerals from the ground surface and load the load into the bucket 108.

[0023] Furthermore, by extending the pair of lift cylinders 114 and rotating the lift arms 107 upward, the bucket 108 that has scooped up the load can be lifted upward. Also, by retracting the bucket cylinder 115, the bucket 108 can be rotated downward via a bell crank, and the load loaded in the bucket 108 can be dropped and unloaded from the bucket 108. Also, by retracting the pair of lift cylinders 114, the lift arms 107 can be rotated downward and the bucket 108 can be lowered. This makes it possible to load loads from the ground surface into the bucket 108 again.

[0024] The user interface 121 is, for example, an information terminal such as a personal computer (PC), tablet terminal, or smartphone, and is connected via wireless communication to be able to communicate information with the work machine control device 200. The positioning device 122 is, for example, a receiver for the Global Navigation Satellite System (GNSS), and is connected to the work machine control device 200, outputting position information of the work machine 100 to the work machine control device 200. Note that the positioning device 122 is not limited to a GNSS receiver, and it is also possible to adopt SLAM (Simultaneous Localization and Mapping), which uses a camera or laser radar to simultaneously estimate the self-position and create an environmental map.

[0025] The work machine control device 200 can be configured, for example, by one or more microcontrollers. The work machine control device 200 includes, for example, an automatic driving control device 210, a hydraulic control device 220, an engine control device 230, and a cruise control device 240. The automatic driving control device 210, the hydraulic control device 220, the engine control device 230, and the cruise control device 240 may all be configured as a single device, or each may be configured as a separate device, or several devices may be combined into a plurality of devices.

[0026] The automatic driving control device 210 receives work instructions and evacuation instructions from, for example, the user interface 121. In addition, the automatic driving control device 210 receives position information of the work machine 100 from, for example, the positioning device 122. In addition, although not shown, the automatic driving control device 210 receives pressure information corresponding to the weight of the load loaded into the bucket 108 from, for example, a pressure sensor that detects the pressure of the hydraulic oil in the cylinder of the bucket cylinder 115. Based on the input information, the automatic driving control device 210 generates a hydraulic control signal, an engine control signal, and a traveling control signal, and outputs them to the hydraulic control device 220, the engine control device 230, and the traveling control device 240, respectively.

[0027] Based on a hydraulic control signal input from the automatic driving control device 210, the hydraulic control device 220 controls the distribution of hydraulic oil from the control valve 112 to the front wheel brake 106F, the rear wheel brake 106R, the pair of steering cylinders 113, the pair of lift cylinders 114, and the bucket cylinder 115. This controls the operations of the front wheel brake 106F, the rear wheel brake 106R, the pair of steering cylinders 113, the pair of lift cylinders 114, and the bucket cylinder 115 described above.

[0028] The engine control device 230 controls the rotation speed of the engine 103 based on an engine control signal input from the automatic driving control device 210. This controls the amount of hydraulic oil discharged from the hydraulic pump 111 and the power transmitted to the pair of front wheels 102F and the pair of rear wheels 102R via the power transmission mechanism 104, the front differential 105F, and the rear differential 105R.

[0029] The travel control device 240 controls, for example, the gear ratio and rotation direction of the power transmission mechanism 104, thereby switching the rotational speed and torque of the pair of front wheels 102F and the pair of rear wheels 102R of the work machine 100, and switching the forward or reverse direction of the work machine 100.

[0030] Figure 3 is a block diagram of the automatic driving control device 210 included in the work machine control device 200 of Figure 2. The automatic driving control device 210 includes, for example, a map information recording unit 211, a behavior management unit 212, a route planning unit 213, and an action generation unit 214. The automatic driving control device 210 is configured, for example, by a central processing unit (CPU), memory, a timer, and one or more microcontrollers and firmware equipped with input / output units (not shown). Each unit of the automatic driving control device 210 shown in Figure 3 represents, for example, each function of the automatic driving control device 210 that is realized by the CPU executing a program recorded in memory.

[0031] FIG. 4 is a schematic diagram showing an example of map information MI recorded in the map information recording unit 211 of the automatic driving control device 210 of FIG. 3. The map information MI includes, for example, position information p0, p1, ..., which are a plurality of coordinate points on an XY coordinate system, and line segment information connecting each piece of position information p0, p1, .... Each piece of position information p0, p1, ... is also assigned attribute information such as the loading positions of loads O1, O2, ... to be loaded onto the work machine 100, loading and unloading positions such as dump trucks D1, D2, ... or dump sites where the work machine 100 unloads the loads O1, O2, ..., or obstacles OB that the work machine 100 must avoid. Note that the map information MI may be information stored in advance in the memory of the control device 200 of the work machine, or may be information generated and updated based on the detection results of external sensors mounted on the work machine 100, such as laser radar or SLAM.

[0032] 3, the behavior management unit 212 receives map information MI from the map information recording unit 211, work instructions WI from the user interface 121, and current position information PI of the work machine 100 from the positioning device 122. In addition, the behavior management unit 212 receives a transport route TR from, for example, a route planning unit 213. The behavior management unit 212 outputs a loading position LP and a loading / unloading position DP, which are target positions, to the route planning unit 213, for example, based on the input work instructions WI.

[0033] Furthermore, the behavior management unit 212 generates an operation mode OM for the work machine 100 based on the input information and outputs it to the operation generation unit 214. The operation mode OM for the work machine 100 includes, for example, a loading mode for excavating a load and loading it into the bucket 108, and a loading / unloading mode for unloading the load from the bucket 108 onto a dump truck, a dump site, or the like. The behavior management unit 212 may also transmit the operation mode OM for the work machine 100 to the user interface 121 as one piece of notification information.

[0034] Fig. 5 is a table showing an example of work instructions WI input to the behavior management unit 212 of the automatic driving control device 210 in Fig. 3. The work instructions WI include, for example, the types O1, O2, ... of cargo to be loaded into the bucket 108, the target loading amounts W1, W2, ... of each of the cargoes O1, O2, ..., the loading position LP which is the excavation position, and the loading / unloading position DP to the dump trucks D1, D2 or the dump site.

[0035] 4 and 5, the position information of the loading position LP, which is the excavation position, for the load O1 is p8, the position information of the loading / unloading position DP, which is the loading position onto the dump truck D1, is p6, and the position information of the loading / unloading position DP, which is the release position of the surplus load O1 that has exceeded the target loading amount W1, is the same as the loading position LP, p8. Also, the position information of the loading position LP, which is the excavation position, for the load O2 is p1, the position information of the loading / unloading position DP, which is the loading position onto the dump truck D2, is p2, and the position information of the loading / unloading position DP, which is the release position of the surplus load O2 that has exceeded the target loading amount W2, is the same as the loading position LP, p1.

[0036] The route planning unit 213 receives as input from the behavior management unit 212 the loading position LP and the loading / unloading position DP as target positions, as well as the position information PI of the work machine 100 from the positioning device 122, and as input map information MI from the map information recording unit 211. Based on the input information, the route planning unit 213 generates a transport route TR, which will be described later, and outputs it to the behavior management unit 212 and the operation generation unit 214.

[0037] The operation generation unit 214 receives the operation mode OM from the behavior management unit 212, the transport route TR from the route planning unit 213, and the position information PI of the work machine 100 from the positioning device 122. The operation generation unit 214, for example, generates a traveling operation for the work machine 100 to travel along the transport route TR. The operation generation unit 214 also generates, for example, loading operations and unloading operations for the cargo O1, O2... in accordance with the operation mode OM of the work machine 100. The operation generation unit 214 generates, for example, a hydraulic control signal HPS and a traveling control signal TCS corresponding to the generated traveling operations, loading operations, and unloading operations, and outputs these to the hydraulic control device 220 and the traveling control device 240, respectively.

[0038] Furthermore, the motion generator 214 calculates the required engine 103 rotation speed from, for example, the traveling motion, the loading motion, and the unloading motion. The motion generator 214 outputs, for example, an engine control signal ECS including the engine 103 rotation speed to the engine control device 230. The traveling control signal TCS generated by the motion generator 214 may be, for example, the accelerator and brake pedal operation amounts, the steering operation amount, and the forward / reverse switch switching signal, similar to the manual operation of the work machine 100. Furthermore, the hydraulic control signal HPS generated by the motion generator 214 may be, for example, the operation amount of the operating levers of the lift arm 107 and the bucket 108.

[0039] Fig. 6 is a flow diagram showing the processing flow of the route planning unit 213 of the automatic driving control device 210 of Fig. 3. Fig. 7 is a diagram showing an example of a transport route TR planned by the work machine control device 200 according to the processing flow PF shown in Fig. 6. Here, the transport route TR is a route of the work machine 100 that loads a load O1 at a loading position LP, moves backward from the loading position LP to a turning position CP, moves forward from the turning position CP, and unloads the load O1 at a loading / unloading position DP.

[0040] 6, the route planning unit 213 first executes a process P1 for acquiring information. In this process P1, the route planning unit 213 acquires, for example, a loading position LP and a loading / unloading position DP as target positions from the behavior management unit 212, and acquires map information MI from the map information recording unit 211.

[0041] Next, the route planning unit 213 executes process P2 for setting targets based on, for example, the acquired loading position LP and loading / unloading position DP. In process P2, the route planning unit 213 sets the coordinates x1, y1 of the loading position LP and the loading orientation θ1 as targets, and also sets the coordinates x2, y2 of the loading / unloading position DP and the loading / unloading orientation θ2 as targets, as shown in Fig. 7. Here, the loading orientation θ1 at the loading position LP and the loading / unloading orientation θ2 at the loading / unloading position DP are set in advance for, for example, the loading position LP and the loading / unloading position DP, and are recorded in memory of the control device 200 of the work machine.

[0042] The loading orientation θ1 and the loading / unloading orientation θ2 are, for example, the azimuth angles of the work machine 100 at the loading position LP and the loading / unloading position DP. The azimuth angle of the work machine 100 is, for example, the angle that the direction facing forward of the work machine 100 makes with respect to the X-axis when the front body 101F and the rear body 101R of the work machine 100 are aligned in a straight line in the fore-and-aft direction. That is, in the example shown in Fig. 7, the work machine 100 is specified to face in the directions of arrows A1 and A2 at the loading position LP and the loading / unloading position DP, respectively, with no angle formed between the front body 101F and the rear body 101R.

[0043] Next, the path planning unit 213 executes process P3 to set candidate turning positions. Here, a turning position is a position where the work machine 100 stops and changes direction after reversing from the loading position LP or the loading / unloading position DP, and includes a turning orientation, which is the azimuth angle of the work machine 100 at the turning position. At least one turning position is required to move from the loading position LP to the loading / unloading position DP. The path planning unit 213 sets one or more candidate turning positions based on, for example, the loading position LP and loading orientation θ1, and the loading / unloading position DP and loading / unloading orientation θ2, which were set in the previous process P2.

[0044] In the example shown in Figure 7, for example, a first turning position CP, a second turning position CP', and a third turning position CP" are set as candidate turning positions. The first turning position CP and the second turning position CP' are set, for example, on the bisector L3 of the included angle between a first straight line L1 that passes through the loading position LP and is parallel to the loading orientation θ1, and a second straight line L2 that passes through the loading / unloading position DP and is parallel to the loading / unloading orientation θ2. The third turning position CP" is set, for example, on the second straight line L2.

[0045] Next, the route planning unit 213 executes process P4 to discard the transport route TR planned in the previous process flow PF, and then executes process P5 to generate new route candidates for the transport route TR. In process P5, the route planning unit 213 plans route candidates, for example, by selecting the loading position LP and unloading position DP set in the previous processes P2 and P3, and one of the turning positions CP, CP', and CP". Here, the route planning unit 213 generates route candidates for the transport route TR that do not include a route with a radius of curvature smaller than the minimum turning radius of the work machine 100, for example.

[0046] Fig. 8 is a diagram showing an example of the route candidate CR generated in the process P5 for generating the route candidate in Fig. 6. Fig. 9 is a graph showing the curvature of the route candidate CR in Fig. 8. The route planning unit 213 generates, for example, a route Rab that reverses straight from point A corresponding to the loading position LP to point B, a route Rba that reaches point C while increasing the curvature from point B in a positive direction at a constant rate of change, and a route Rcd that reaches point D corresponding to the turning position CP while decreasing the curvature from point C in a positive direction at a constant rate of change.

[0047] Furthermore, the path planning unit 213 generates, for example, a path Rde that reaches point E while increasing the curvature from point D in the negative direction at a constant rate of change, a path Ref that reaches point F while decreasing the curvature from point E in the negative direction at a constant rate of change, and a path Rfg that moves forward in a straight line from point F to point G corresponding to the loading / unloading position DP. That is, in this embodiment, the curved portion of each path candidate CR generated by the path planning unit 213 of the work machine control device 200 is, for example, a clothoid curve. Note that the path planning unit 213 may also simultaneously generate path candidates in the opposite direction, for example, moving backward from point G to point D and moving forward from point D to point A.

[0048] Next, the route planning unit 213 executes process P6 to determine whether or not a route candidate can be generated. In process P6, if a route candidate was generated in the previous process P5, the route planning unit 213 determines that a route candidate can be generated (Yes), executes process P7 to save the generated route candidate, and executes the next process P8. On the other hand, in process P6, if a route candidate was not generated in the previous process P5, the route planning unit 213 determines that a route candidate cannot be generated (No), and executes the next process P8 without executing process P7 to save the route candidate.

[0049] In process P8, the route planning unit 213 determines whether or not there are any unselected turning positions CP, CP', CP". In this process P8, if the route planning unit 213 determines that there are unselected turning positions CP, CP', CP" (Yes), it executes process P9 to select one of the unselected turning positions CP, CP', CP", and again repeats processes P5 to P8 to generate route candidates.

[0050] As a result, the route planning unit 213 generates multiple route candidates for the transport route TR that do not include a route with a radius of curvature smaller than the minimum turning radius of the work machine 100. On the other hand, if the route planning unit 213 determines in process P8 that there are no unselected turning positions CP, CP', CP" (No), it executes process P10 to determine whether or not there are any route candidates stored in the memory of the control device 200 of the work machine.

[0051] In process P10, if the route planning unit 213 determines that there are no route candidates recorded in memory (No), it executes process P11 to notify the behavior management unit 212 and the action generation unit 214 that a route candidate could not be generated, and ends the process flow PF shown in Fig. 6. In this case, the action generation unit 214 notifies the user, for example, via the user interface 121, that a route candidate could not be generated.

[0052] On the other hand, if the route planning unit 213 determines in process P10 that there are route candidates recorded in memory (Yes), it executes process P12 to select a transportation route TR from the multiple route candidates. In process P12, the route planning unit 213 calculates an evaluation value for each of the multiple route candidates based on at least one of the route length, curvature, or number of turning points of each of the multiple route candidates, and selects the route candidate with the highest evaluation value from the multiple route candidates as the transportation route TR.

[0053] Figure 10 is a flow diagram showing details of process P12 for selecting a transportation route TR in Figure 6. When process P12 shown in Figure 10 starts, the route planning unit 213 first executes process P121 for selecting one route candidate from multiple route candidates. Next, the route planning unit 213 executes, for example, process P122 for calculating the route length, process P123 for calculating the maximum curvature, and process P124 for calculating the number of turning back positions for the selected route candidate.

[0054] Next, the route planning unit 213 executes process P125 to calculate an evaluation value for each route candidate based on at least one of the route length, curvature, or number of turning positions of the selected route candidate. Specifically, when the route length of the route candidate is used as an index of the evaluation value, an evaluation value calculation formula is set so that the shorter the route length, the higher the evaluation value. When curvature is used as an index of the evaluation value, an evaluation value calculation formula is set so that the smaller the maximum curvature, the higher the evaluation value. When the number of turning positions is used as an index of the evaluation value, an evaluation value calculation formula is set so that the fewer the number of turning positions, the higher the evaluation value.

[0055] From the above viewpoint, the calculation formula for the evaluation value EV of a route candidate can be set, for example, as shown in the following formula (1), where α, β, and γ are coefficients, Lr is the route length of the route candidate, Cmax is the maximum curvature of the route candidate, and Nc is the number of turning points of the route candidate. Note that the evaluation value EV of a route candidate may also be calculated using other indices, such as increasing the evaluation value EV as the gradient of the route candidate decreases.

[0056] EV=α(1 / Lr)+β(1 / Cmax)+γ(1 / Nc)...(1)

[0057] Next, the route planning unit 213 executes process P126 to determine whether or not there is an unselected route candidate. In process 126, if the route planning unit 213 determines that an unselected route candidate exists among the multiple route candidates recorded in memory (Yes), it selects the unselected route candidate in the above-mentioned process P121 and repeats processes P122 to P125. On the other hand, if the route planning unit 213 determines in process 126 that an unselected route candidate does not exist among the multiple route candidates recorded in memory (No), it executes process P127 to select a transportation route TR.

[0058] In process P127, the route planning unit 213 selects the route candidate with the highest evaluation value from among the multiple route candidates as the transportation route TR, and ends process P12 shown in Fig. 10. Thereafter, the route planning unit 213 executes process P13 to notify the behavior management unit 212 and the action generation unit 214 of the selected transportation route TR, as shown in Fig. 6, and ends process flow PF shown in Fig. 6.

[0059] The operation of the control device 200 for a work machine according to this embodiment will now be described.

[0060] 4 and 7, for example, the work machine control device 200 plans a transport route TR that loads a load O1 at a loading position LP, moves backward from the loading position LP to a turning position CP, moves forward from the turning position CP, and unloads the load O1 at a loading / unloading position DP. As described above, the work machine control device 200 generates multiple route candidates for the transport route TR that do not include a route with a radius of curvature smaller than the minimum turning radius of the work machine 100, based on the position information p8(x1, y1), p6(x2, y2) of the loading position LP and the loading / unloading position DP, the loading orientation θ1 of the work machine 100 at the loading position LP, and the loading / unloading orientation θ2 of the work machine 100 at the loading / unloading position DP. In addition, the work machine control device 200 calculates an evaluation value for each of the multiple route candidates based on at least one of the route length, curvature, or number of turning positions of each of the multiple route candidates, and selects the route candidate with the highest evaluation value from the multiple route candidates as the transport route TR.

[0061] With this configuration, the work machine control device 200 of this embodiment can plan a transport route TR for the work machine 100 that is efficient and has excellent tracking ability. More specifically, the work machine control device 200 of this embodiment can automatically plan an efficient transport route TR that includes appropriate turning positions in accordance with obstacles and site conditions, without the need to input teaching data for turning positions. More specifically, by increasing the evaluation value of a candidate route that has a shorter route length, smaller curvature, and fewer turning positions, for example, it is possible to plan a transport route TR that can reduce the energy consumption of the work machine 100 and limit the load on the road surface and the work machine 100.

[0062] Furthermore, when generating multiple route candidates, the control device 200 for a work machine of this embodiment sets the turning back positions CP, CP' of each route candidate on the bisector L3 of the included angle between a first straight line L1 that passes through the loading position LP and is parallel to the loading orientation θ1, and a second straight line L2 that passes through the loading and unloading position DP and is parallel to the loading and unloading orientation θ2, as shown in Figure 7. With this configuration, the control device 200 for a work machine of this embodiment can make the curved portions of the route candidate before and after the turning back positions CP, CP' have the same shape or the same curvature, thereby shortening the route length of the route candidate and reducing the maximum curvature.

[0063] Furthermore, in the construction machine control device 200 of this embodiment, the routes Rbc, Rcd, Rde, and Ref, which are the curved portions of each route candidate CR generated, are clothoid curves, as shown in Figures 8 and 9. By making the curved portions of the route candidate CR clothoid curves in this way, there is no discontinuity in curvature even at points where the straight line sections of the routes Rab and Rfg switch with the curved sections of the routes Rbc and Ref. This allows the construction machine 100 to reliably follow the transport route TR selected from multiple route candidates.

[0064] As described above, according to this embodiment, it is possible to provide a control device 200 for a work machine that is capable of planning a transport route TR for the work machine 100 that is efficient and has excellent tracking ability.

[0065] [Embodiment 2] 1 to 3 and 5 to 10 of the above-described embodiment will be used to explain a second embodiment of a control device for a work machine according to the present disclosure, with reference to Fig. 11. Fig. 11 is a diagram showing an example of a loading position LP of the second embodiment of the control device for a work machine according to the present disclosure.

[0066] In the construction machine control device 200 of this embodiment, when generating multiple route candidates, the loading position LP includes multiple pieces of position information p11, p12, p13, ..., p1n, and the loading orientation θ1 includes loading orientations θ11, θ12, θ13, ..., θ1n for each of the multiple pieces of position information p11, p12, p13, ..., p1n of the loading position LP. In other words, the loading position LP of this embodiment is defined in the map information MI as, for example, an excavation range or loading range where a load such as a stockpile exists.

[0067] In this embodiment, the control device 200 of the work machine acquires, for example, in process P1 shown in Fig. 6, a plurality of pieces of position information p11, p12, p13, ..., p1n for the loading position LP and loading orientations θ11, θ12, θ13, ..., θ1n. Furthermore, in process P2 shown in Fig. 6, the control device 200 of the work machine sets each piece of position information p11, p12, p13, ..., p1n and loading orientations θ11, θ12, θ13, ..., θ1n as targets. Furthermore, in this process P2, the control device 200 of the work machine sets candidate steering positions for each of the set targets.

[0068] Therefore, in the above-mentioned process P12, the construction machine control device 200 of this embodiment also calculates evaluation values ​​for a plurality of route candidates that include each of the above-mentioned position information p11, p12, p13, ..., p1n and the loading orientations θ11, θ12, θ13, ..., θ1n. As a result, for example, it is possible to select the transport route TR with the shortest route length as the route candidate with the highest evaluation value. Therefore, according to this embodiment, it is possible to provide a construction machine control device 200 that is capable of planning a transport route TR for the construction machine 100 that is efficient and has excellent tracking ability.

[0069] The above has described in detail an embodiment of the work machine control device 200 according to the present disclosure using the drawings, but the specific configuration is not limited to this embodiment, and even if there are design changes and the like within the scope that does not deviate from the gist of the present disclosure, they are included in the present disclosure. [Explanation of symbols]

[0070] 100 Work Machinery 200 Control device for work machine Cmax Maximum curvature (curvature) CP Switching position CR route candidates DP loading / unloading position EV evaluation value L1 1st straight line L2 2nd straight line L3 Bisector of included angle LP loading position Lr Path length Nc Number of turning positions O1 cargo O2 cargo p1 Loading location information p11-p1n Loading position location information p2 Location information of loading and unloading points p6 Location information of loading and unloading points p8 Loading location information Rbc pathway (curved portion of pathway candidate) Rcd route (curved part of the route candidate) Rde route (curved portion of route candidate) Ref route (curved part of the route candidate) TR transport route θ1 Loading direction θ11-θ1n Loading direction θ2 Loading / unloading direction

Claims

1. A control device for a work machine that plans a transport route for a work machine that loads a load at a loading position, moves backward from the loading position to a turning position, moves forward from the turning position, and unloads the load at a loading / unloading position, The control device generating a plurality of route candidates for the transport route that do not include a route with a radius of curvature smaller than the minimum turning radius of the work machine based on position information of the loading position and the loading and unloading position by the work machine, the loading orientation of the work machine at the loading position, and the loading and unloading orientation of the work machine at the loading and unloading position; When generating the plurality of route candidates, the turning back position of each of the route candidates is set on a bisector of an included angle between a first straight line that passes through the loading position and is parallel to the loading orientation, and a second straight line that passes through the loading position and is parallel to the loading orientation, select at least one of the route length, curvature, or number of turning positions of each of the plurality of route candidates as an index of an evaluation value of each of the route candidates, and calculate an evaluation value of each of the route candidates so that if the selected index is the route length, the evaluation value becomes higher as the route length becomes shorter, if the selected index is the curvature, the evaluation value becomes higher as the curvature becomes smaller, or if the selected index is the number of turning positions, the evaluation value becomes higher as the number of turning positions becomes smaller; A control device for a work machine, characterized in that the route candidate with the highest evaluation value is selected as the transport route from among the plurality of route candidates.

2. 2. The control device for a work machine according to claim 1, wherein, when the plurality of route candidates are generated, the loading position includes a plurality of pieces of position information, and the loading orientation includes the loading orientation for each of the plurality of pieces of position information of the loading position.

3. 2. The control device for a work machine according to claim 1, wherein the curved portion of each of the route candidates is a clothoid curve.

Images