Work machine control system and work machine

Abstract

To properly control a work machine according to an excavation amount in automatically excavating an object to be excavated and transporting to a target position to load.SOLUTION: A control system of a work machine includes an automatic operation control device 200 controlling an operation of a work machine having a work tool and a load acquisition device 142 measuring a movable load of an object in the work tool. The automatic operation control device 200 comprises a motion management portion 211 setting a target position that is a movement destination of the work machine. The motion management portion 211 decides the target position according to the movable load acquired by the load acquisition device 142.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a control system for a work machine, and a work machine equipped with the control system for the work machine. [Background technology]

[0002] BACKGROUND ART A work machine and a control system for the work machine have been proposed that automatically excavate an object to be excavated and load it at a predetermined loading position.

[0003] For example, Patent Document 1 discloses an automatic excavation technology in which "an automatic excavation machine automatically performs a series of processes of excavating an object with the excavator and loading the excavated material onto a loading target, the automatic excavation machine comprises a measuring instrument for determining the distance from the excavator to the excavation object and the loading target, an excavation object recognition means for recognizing the three-dimensional shape of the excavation object based on the output of the measuring instrument, an excavation target position calculation means for calculating the excavation target position of the recognized excavation object, a loading target position calculation means for calculating the relative position of the loading target with respect to the excavator and the relative attitude of the excavator with respect to the loading target based on the output of the measuring instrument, and calculating the loading target position based on the calculation results, an automatic positioning means for automatically positioning a work machine at the calculated excavation target position and loading target position, an automatic excavation control means for automatically excavating at the excavation target position, and an automatic loading control means for automatically loading the excavated material at the loading target position (abstract excerpt)." [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 10-88625 Summary of the Invention [Problem to be solved by the invention]

[0005] When excavating within a work area, the amount of excavation may be either excessive or insufficient. However, the technology disclosed in Patent Document 1 does not anticipate such situations. Therefore, the technology disclosed in Patent Document 1 does not allow for appropriate control of the work machine according to the amount of excavation.

[0006] The present invention has been made in consideration of the above circumstances, and aims to provide a technology for appropriately controlling a work machine according to the amount of excavation when automatically excavating an excavation object, transporting it to a target location, and loading it. [Means for solving the problem]

[0007] In order to achieve the above object, a representative aspect of the present invention is a control system for a work machine having an automatic driving control device that controls the operation of a work machine having a work implement, a load acquisition device that measures the live load of an object inside the work implement, and a positioning device that acquires the current position of the work machine, wherein the automatic driving control device comprises: a behavior management unit that sets a target position to which the work machine is to move; a route planning unit that generates a target route that is a travel route between the current position acquired by the positioning device and the target position set by the behavior management unit; and an action generation unit that generates a control signal for operating the work machine in accordance with the target route generated by the route planning unit, wherein the behavior management unit determines the target position in accordance with the live load acquired by the load acquisition device, and the action generation unit drives the work machine to travel to the target position, and the action generation unit generates a control signal for operating the work machine in accordance with the target route generated by the route planning unit. of It is characterized by generating a control signal for loading onto the loading target. [Effects of the Invention]

[0008] According to the present invention, when an excavation target is automatically excavated, transported to a target position, and loaded, the work machine can be appropriately controlled according to the excavation volume. Note that problems, configurations, and effects other than those described above will become clear from the description of the following embodiments. [Brief explanation of the drawings]

[0009] [Figure 1]FIG. 1 is an explanatory diagram for explaining an overview of a first embodiment. [Figure 2] 1 is a schematic diagram of the appearance of a wheel loader according to a first embodiment. FIG. [Figure 3] FIG. 1 is a configuration diagram of a control system for a wheel loader according to a first embodiment. [Figure 4] FIG. 2 is a hardware configuration diagram of the control system according to the first embodiment. [Figure 5] FIG. 1 is a functional block diagram of an automatic driving control device according to a first embodiment. [Figure 6] 5(a) to 5(c) are explanatory diagrams for explaining map data according to the first embodiment. [Figure 7] FIG. 1A is an explanatory diagram for explaining an example of a work instruction according to the first embodiment, and FIGS. 1B to 1D are explanatory diagrams for explaining an example of a target route according to the first embodiment. [Figure 8] 4A is an explanatory diagram for explaining an example of upper and lower limit data of excavation volume according to the first embodiment, and FIG. 4B is an explanatory diagram for explaining an example of lower limit data of loading volume according to the first embodiment. [Figure 9] 10 is a flowchart of a behavior management process according to the first embodiment. [Figure 10] FIG. 11 is an explanatory diagram for explaining an example of lower limit correction data according to the second embodiment. [Figure 11] 10 is a flowchart of a behavior management process according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of a work machine assistance system according to the present invention will be described with reference to the drawings.

[0011] <<First Embodiment>> First, an overview of the first embodiment will be described using Fig. 1. In this embodiment, a work machine 100 such as a wheel loader that autonomously travels within a work area 300 excavates an excavation target 310 and transports the excavated object to a loading target 320 in accordance with work instructions. The loading target 320 is a hopper, a dump truck, or the like.

[0012] Below, a construction machine 100 that achieves this and its control system will be described. Here, a wheel loader will be used as an example of the construction machine 100.

[0013] FIG. 2 is a diagram showing a schematic view of the exterior of the wheel loader 100 of this embodiment, and FIG. 3 is a diagram showing a control system 180 of the wheel loader 100 of this embodiment.

[0014] The wheel loader 100 comprises a vehicle body 110 and an articulated work machine 120 attached to the front of the vehicle body 110.

[0015] The work implement 120 is a work device driven by at least one actuator. The work implement 120 shown in Figure 2 includes a bucket 121, a lift arm 122, a bell crank 123, a bucket link 124, a lift cylinder 125, a bucket cylinder 126, and a steering cylinder 112.

[0016] The bucket 121 is a work implement provided at the front of the vehicle body. The lift cylinder 125 and the bucket cylinder 126 are hydraulic actuators (hydraulic cylinders) that drive the bucket 121 and the lift arm 122, respectively, and are attached between the work implement 120 and the vehicle body 110. One lift arm 122 and one lift cylinder 125 are provided on each side of the vehicle body 110.

[0017] The lift arm 122 is rotatably supported by the vehicle body 110, and rotates up and down (moves up and down) in accordance with the extension and retraction of the lift cylinder 125. The bucket 121 rotates (dumps or crowds) in accordance with the extension and retraction of the bucket cylinder 126.

[0018] One end of the lift cylinder 125 is connected to the lift arm 122, and the other end is connected to the vehicle body 110. One end of the bucket cylinder 126 is connected to the bell crank 123, and the other end is connected to the vehicle body 110. The link mechanism that operates the bucket 121 of the wheel loader 100 shown in FIG. 2 is a Z-link type (bell crank type) that uses the bell crank 123.

[0019] The vehicle body 110 is provided with four wheels (a front right tire 131FR, a front left tire 131FL, a rear right tire 131RR (see FIG. 2), and a rear left tire 131RL). Hereinafter, unless there is a need to distinguish between them, they will be collectively referred to as tires 131. Each tire 131 is driven by a power transmission device that uses the engine 111 (see FIG. 3) as a power source. Driving force is transmitted to the ground via each tire 131, causing the wheel loader 100 to move forward or backward.

[0020] The wheel loader 100 also has an articulated steering mechanism, and turns by creating an angle difference between the front and rear of the vehicle body around an axis that is vertical to the vehicle body as the steering cylinder 112 extends and retracts.

[0021] As shown in FIG. 3 , the wheel loader 100 includes an engine 111, a steering cylinder 112, a driving force transmission device 113, a hydraulic pump 114, a control valve 115, a center joint 132C, brakes 133F and 133R, a front differential 134F, a rear differential 134R, a positioning device 141, a load acquisition device 142, a control system 180, and a user interface 190.

[0022] As shown in FIG. 3, the control system 180 includes an automatic driving control device 200, a hydraulic control device 160, an engine control device 150, and a driving control device 170.

[0023] The engine 111 is a power source of the wheel loader 100. The engine 111 drives a hydraulic pump 114 and a driving force transmission device 113.

[0024] The driving force transmission device 113 transmits the driving force of the engine 111 to the front right tire 131FR and the front left tire 131FL via the center joint 132C and the front differential 134F, and to the rear right tire 131RR and the rear left tire 131RL via the center joint 132C and the rear differential 134R, thereby accelerating the wheel loader 100.

[0025] Furthermore, the hydraulic pump 114 is driven by the engine 111 and supplies hydraulic oil to the control valve 115. The hydraulic oil is distributed by the control valve 115 and drives the steering cylinder 112, lift cylinder 125, bucket cylinder 126, and brakes 133F, 133R. The steering cylinder 112, lift cylinder 125, and bucket cylinder 126 expand and contract as a result of the supply of hydraulic oil, thereby changing the angle between the front and rear of the vehicle body, the angle of the lift arm 122 relative to the front of the vehicle body, and the angle of the bucket 121. Furthermore, when the brakes 133F, 133R are closed by the hydraulic oil, the rotation of the tires 131FR, 131FL, 131RR, and 131RL is suppressed, and the wheel loader 100 decelerates and stops.

[0026] The positioning device 141 acquires current position information of the wheel loader 100. The positioning device 141 is a Global Navigation Satellite System (GNSS). However, the positioning device 141 is not limited to this. The positioning device 141 may perform positioning using a known Simultaneous Localization and Mapping (SLAM) method using a camera or Light Detection and Ranging (LiDAR).

[0027] The load acquisition device 142 acquires live load information of the bucket 121. The load acquisition device 142 includes, for example, a pressure sensor attached to the lift cylinder 125 and a calculation device. The pressure sensor acquires the bottom pressure of the lift cylinder 125, and the calculation device calculates the live load of the object excavated by the bucket 121 from the bottom pressure. The calculation device calculates the live load by, for example, detecting the weight of the bucket 121 when it is empty in advance and subtracting the weight of the bucket 121 from the total weight including the bucket 121 and the load. The calculation result is transmitted to the automatic driving control device 200 as load information. Note that the sensor that acquires the load is not limited to a pressure sensor. For example, it may be a strain sensor or the like.

[0028] The user interface 190 may be a PC, tablet terminal, smartphone, or other device that can input work instructions, which will be described later.

[0029] The automatic driving control device 200 generates an engine control signal, a hydraulic control signal, and a driving control signal in accordance with work instructions from the user interface 190, current location information from the positioning device 141, and load information from the load acquisition device 142, and transmits them to the engine control device 150, the hydraulic control device 160, and the driving control device 170, respectively.

[0030] In response to these signals, the engine control device 150 controls the rotation speed of the engine 111, the hydraulic control device 160 controls the opening and closing degree of the control valve 115, and the driving control device 170 controls the gear ratio and rotation direction of the driving force transmission device 113.

[0031] The control system 180 is a computer for executing various information processes relating to the operation of the wheel loader 100, and is realized by, for example, a microcomputer.

[0032] 4 is a diagram showing an example of the hardware configuration of the control system 180. The control system 180 includes a CPU (Central Processing Unit) 221, a memory 182, a storage device 183, and an input / output interface (I / F) 184. The control system 180 may further include a communication interface (I / F) 185. The CPU 181, memory 182, and storage device 183 may be provided for each unit in the control system 180. A plurality of configurations may be used in combination.

[0033] CPU 181 loads a program stored in storage device 183 into memory 182 and executes it. The memory is, for example, RAM (Random Access Memory) and functions as a work area. Storage device 183 is ROM (Read Only Memory), flash memory, etc., and stores programs, data used in processing by CPU 181, data generated during processing, data generated by processing, etc.

[0034] In this embodiment, each function of the control system 180 is realized by, for example, the CPU 181 loading a program stored in the storage device 183 into the memory 182 and executing it.

[0035] The input / output I / F 184 is an interface for inputting and outputting data. In this embodiment, data is input and output to and from a user interface 190. In this embodiment, the operator of the wheel loader 100 inputs work instructions via the user interface 190.

[0036] The storage device 183 includes a semiconductor memory such as a ROM or flash memory, but may include a magnetic storage device such as a hard disk drive instead.

[0037] Next, the automatic driving control device 200 will be described. Fig. 5 is a functional block diagram of the automatic driving control device 200 of this embodiment. The automatic driving control device 200 includes a behavior management unit 211, a route planning unit 212, and an action generation unit 213. The automatic driving control device 200 also includes map data 220.

[0038] If instructions are received from the outside without going through the user interface 190, a receiving unit is further provided.

[0039] The behavior management unit 211 determines a target position and transmits it to the path planning unit 212. The behavior management unit 211 also acquires work instructions, the current position, load information, and the target path, and determines the operation mode of the wheel loader 100. Furthermore, when the wheel loader 100 performs excavation, the behavior management unit 211 of this embodiment uses the load information to determine whether the excavation amount is appropriate. Then, the target position is determined according to the determination result. For this reason, the behavior management unit 211 of this embodiment calculates the target excavation amount (target live load) WB, and its upper limit (excavation amount upper limit; upper limit value) WBmax and lower limit (excavation amount lower limit; lower limit value) WBmin.

[0040] When determining the operation mode, the behavior management unit 211 acquires a work instruction from the user interface 190. The current position is acquired from the positioning device 141. Load information is acquired from the load acquisition device 142. Then, the target route is acquired from the route planning unit 212. The behavior management unit 211 also transmits the determined operation mode to the operation generation unit 213 and also transmits it to the user interface 190 as notification information.

[0041] In this embodiment, the operation modes include, for example, a traveling mode, an excavation mode, a loading mode, and a dumping mode. The traveling mode is a mode in which the wheel loader 100 travels. Here, traveling refers to, for example, an operation in which the wheel loader 100 travels along a target route by accelerating and decelerating the vehicle body 110 and extending and retracting the steering cylinder 112. The excavation mode, loading mode, and dumping mode are modes in which the wheel loader 100 excavates, loads, and dumps soil, respectively. Here, excavation refers to, for example, an operation in which the vehicle body 110 is accelerated and decelerated to plunge the bucket 121 into an excavation target, and then the lift arm 122 is raised by intermittently extending the lift cylinder 125 and the bucket cylinder 126, thereby intermittently crowding the bucket 121 until it reaches a full crowd state, thereby scooping up the excavation target into the bucket 121. Loading is an operation in which, for example, while accelerating or decelerating the vehicle body 110, the lift cylinder 125 is extended to raise the lift arm 122 while approaching the loading target, causing the bucket 121 to reach the top of the loading target, and then the bucket cylinder 126 is retracted to dump the bucket 121 and drop the object in the bucket 121 onto the loading target. Discharging is an operation in which, for example, the bucket cylinder 126 is retracted at the discharge position to dump the bucket 121 and drop the object in the bucket 121 to the discharge position. When the operation generation unit 213, which will be described later, receives instructions for these operation modes from the behavior management unit 211, it outputs predetermined control signals to each unit according to each operation mode, and controls the operation of the wheel loader 100.

[0042] The route planning unit 212 uses the map data 220 to calculate a target route, which is a travel route from the current position of the wheel loader 100 to the target position, and transmits it to the behavior management unit 211 and the action generation unit 213. The route planning unit 212 receives the target position from the behavior management unit 211. In addition, it receives the current position from the positioning device 141.

[0043] In the travel mode, the operation generation unit 213 generates a travel operation signal to cause the wheel loader 100 to travel from the current position to the target position along the target route. The operation generation unit 213 transmits the travel operation signal to the travel control device 170 as a travel control signal and to the hydraulic control device 160 as a hydraulic control signal. The operation generation unit 213 also generates work operation signals for the driving force transmission device 113 and each hydraulic cylinder to perform excavation, loading, or soil discharge according to the operation mode.

[0044] The motion generator 213 also calculates the required engine speed from the traveling motion and the working motion, and transmits it as an engine control signal to the engine control device 150. For example, similar to conventional manual operation, the traveling control signal may be the accelerator and brake pedal operation amount, the steering operation amount, and the forward / reverse switch switching signal. Furthermore, the hydraulic control signal may be the lever operation amount of the lift arm 122 and the bucket 121.

[0045] Next, the map data 220 will be described. The map data 220 is stored in advance in the storage device 183. Fig. 6(a) is a diagram for explaining the map data 220 of this embodiment, and Fig. 6(b) and Fig. 6(c) are examples of the map data 220 of this embodiment.

[0046] The map data 220 includes a plurality of points (nodes) within the work area and line segments (arcs) connecting them. For example, when the work area is defined by the coordinate system shown in Fig. 4(a), the map data 220 includes coordinates 222 and attributes 223 of each point 221, as shown in Fig. 6(b), and information on end points 225 and 226 of each line segment 224, as shown in Fig. 6(c). In the figure, Q1 and Q2 are excavation targets, R1 and R2 are loading targets, and O1 is an obstacle.

[0047] Next, the work instructions 230 and the target route 240 will be described.

[0048] 7(a) shows an example of a work instruction 230. The work instruction 230 includes, for example, an identifier (ID) 231 assigned to each work instruction, a type of object 232, a target loading amount (target loading load) 233, a loading position 234, an excavation position 235, and a dumping position 236. The behavior management unit 211 carries out this work instruction 230 every time it is received from the user interface 190.

[0049] For example, the work instruction 230 with the identifier Ins01 is an instruction to excavate the object M1 at the excavation position Q1, load it at the loading position R1, and complete the work when the loading amount reaches W1. Note that in the work instruction 230 with the identifier Ins01, if the excavation amount is excessive or insufficient, the soil discharge position 236 where the soil is discharged is the same position as the excavation position Q1.

[0050] When the behavior management unit 211 receives the work instruction 230 with this identifier Ins01, it first sets the operation mode to the travel mode, sets the digging position Q1 (p8) as the target position, and transmits it to the path planning unit 212.

[0051] The route planning unit 212 generates a target route 240 from the current position to the target position p8 and transmits it to the behavior management unit 211 and the action generation unit 213. Here, when the current position is p0, an example of the target route 240 generated by the route planning unit 212 is shown in FIG. 7(b). As shown in this figure, the target route 240 includes passing points 241 including positions from the current position to the target position, and an FNR 242 indicating the traveling direction between each point. In the FNR 242, forward movement is represented by F and reverse movement is represented by R.

[0052] In executing this work instruction 230, the behavior management unit 211 of this embodiment determines the target position after excavation according to the live load information acquired by the load acquisition device 142. For example, if the actual excavation amount determined by the live load information is less than the excavation amount upper limit WBmax and equal to or greater than the excavation amount lower limit WBmin, the loading position 234 is set as the target position. In other cases, the soil discharge position 236 is set as the target position.

[0053] Furthermore, multiple work instructions 230 may be received at once. In this case, the behavior management unit 211 executes the multiple work instructions sequentially.

[0054] Next, a method for calculating the target excavation volume WB and its upper limit (excavation volume upper limit) WBmax and lower limit (excavation volume lower limit) WBmin by the behavior management unit 211 of this embodiment will be described.

[0055] The target excavation volume WB is determined by the target loading volume (target loading weight) WT of the work instruction 230, the current loading volume WA, and the standard excavation volume WS of the bucket 121 of the wheel loader 100. The current loading volume WA is obtained by adding the excavation volume up to the current time (actual excavation volume). The actual excavation volume is the live load information of the bucket 121 acquired from the load acquisition device 142.

[0056] The behavior management unit 211 first calculates the remaining loading amount WR, which is the difference between the target loading amount WT and the already loaded amount WA. Then, the remaining loading amount WR is compared with the standard excavation amount WS, and the smaller value is set as the target excavation amount WB. The behavior management unit 211 calculates and updates the target excavation amount WB using this procedure every time loading is completed.

[0057] This is to excavate as much as possible in one excavation without exceeding the standard excavation volume. Excavating as much as possible is to reduce the number of operations, i.e., the total work time, and keeping the excavation volume within the standard excavation volume is to prevent spillage of the load.

[0058] For example, if the target loading volume WT is 10 tons and the standard excavation volume WS of the bucket 121 is 4 tons, the first target excavation volume WB is 0 because the amount already loaded is 0, and the remaining loading volume WR is 10 tons. Therefore, the target excavation volume WB is calculated as 4 tons, which is the smaller of the remaining loading volume WR (10 tons) and the standard excavation volume WS (4 tons). The second target excavation volume WB is calculated as 4 tons, which is the smaller of the remaining loading volume WR (10 tons - 4 tons = 6 tons) and the standard excavation volume WS (4 tons). The third target excavation volume WB is calculated as 2 tons, which is the smaller of the remaining loading volume WR (6 tons - 4 tons = 2 tons) and the standard excavation volume WS (4 tons).

[0059] Furthermore, once the target excavation volume WB is determined, the behavior management unit 211 identifies an upper excavation volume limit WBmax and a lower excavation volume limit WBmin. The lower excavation volume limit WBmin is determined by the distance (route distance) L1 of the target route. An example of the relationship between the target excavation volume WB, the upper excavation volume limit WBmax, the lower excavation volume limit WBmin, and the route distance L1 is shown in FIG. 8(a). This data is stored in advance in the storage device 183 or the like as excavation volume upper and lower limit data 510.

[0060] As shown in this figure, the excavation volume upper limit WBmax is a value obtained by adding a predetermined fixed margin (upper limit margin) to the target excavation volume WB. The upper limit margin is specified, for example, as a percentage of the target excavation volume WB. The upper limit margin may be changed, for example, in response to the request of the loading side (dump truck). In this case, for a 10-ton truck, if the upper limit margin is 1 ton, the upper limit margin is specified as 10%, for example.

[0061] The excavation volume lower limit WBmin is a value obtained by subtracting a margin (lower limit margin) that varies depending on the path distance L1 from the target excavation volume WB. The lower limit margin is specified, for example, as a percentage of the target excavation volume WB. Furthermore, as shown in this figure, the lower limit margin is set to a larger value, for example, the shorter the path distance L1. In other words, the shorter the path distance L1, the smaller the value of the excavation volume lower limit WBmin.

[0062] In this embodiment, the wheel loader 100 excavates at the excavation position, then moves to the loading position and performs loading. Therefore, the path distance L1 is the distance from the excavation position to the loading position. In such an environment, if the path distance L1 is short, even if the excavation amount is insufficient, it is more efficient to travel to the loading position and perform the next excavation rather than releasing the soil and excavating again, as this will increase the amount that can be loaded per hour.

[0063] Every time the target excavation volume WB is updated, the behavior management unit 211 calculates the excavation volume upper limit WBmax and the excavation volume lower limit WBmin using the excavation volume upper and lower limit data 510. Note that instead of the excavation volume upper and lower limit data 510, an upper limit margin and a lower limit margin may be stored in the storage device 183.

[0064] When calculating the target excavation volume WB, the behavior management unit 211 calculates the already loaded volume WA and the remaining loaded volume WR. A predetermined margin (loading volume margin) may also be set for the target loading volume WT used at this time. An example of the relationship between the loading volume margin set for the target loading volume WT and the route distance L1 is shown in FIG. 8(b). This data is stored in advance in the storage device 183 or the like as loading volume lower limit data 520.

[0065] As shown in this figure, a loading amount margin is set for the target loading amount WT, and is set as the loading amount lower limit WTmin. The loading amount margin is stored in advance in the storage device 183 or the like. When calculating the remaining loading amount WR, the behavior management unit 211 sets the remaining loading amount WR to 0 if the already loaded amount WA is less than the target loading amount WT but is equal to or greater than the loading amount lower limit WTmin. As a result, if the already loaded amount WA is equal to or greater than the loading amount lower limit WTmin, the target excavation amount becomes 0, and it is determined that the work is complete.

[0066] Next, the flow of behavior management processing, mainly by the behavior management unit 211, of the automatic driving control device 200 when a work instruction 230 is acquired will be described. FIG. 9 shows the processing flow of the behavior management processing of this embodiment. The current position is acquired from the positioning device 141 at predetermined time intervals. In the following processing, the automatic driving control device 200 uses the latest current position acquired at that time.

[0067] First, upon receiving the work instruction 230, the behavior management unit 211 first sets an initial target excavation volume WB and a loading volume lower limit WTmin (step S1100). Here, the target loading volume 233 in the work instruction 230 is set as the initial remaining loading volume WR, and is compared with the standard excavation volume WS to determine the target excavation volume WB using the above method. In addition, the target loading volume 233 is set as WT, and the loading volume lower limit WTmin is calculated using the loading volume margin.

[0068] Next, the behavior management unit 211 sets the excavation position as the target position (step S1101). Here, the excavation position is acquired from the work instruction 230 (excavation position 235).

[0069] Then, the behavior management unit 211 acquires the target route (step S1102). Here, the behavior management unit 211 transmits the target position to the route planning unit 212. The route planning unit 212 uses the map data 220 to generate the target route using the current position and the target position.

[0070] For example, suppose that work Ins01 of the work instruction 230 is being performed and the position of the wheel loader 100 when this work instruction is received is p0. In this case, the current position is p0 in the map data 220. Furthermore, the excavation position Q1 is p8 in the map data 220. The target route 240 created in this case is as shown in FIG. 7(b). That is, the route planning unit 212 creates a route that advances in order between each point from p0 to p8.

[0071] Thereafter, the behavior management unit 211 controls the wheel loader 100 to move to the excavation position (step S1103). The behavior management unit 211 sets the operation mode of the wheel loader 100 to a traveling mode and transmits this to the behavior generation unit 213. The behavior management unit 211 also causes the path planning unit 212 to transmit the generated target path to the behavior generation unit 213. The behavior generation unit 213 generates and outputs various control signals to travel to the target position along the target path.

[0072] Once the wheel loader 100 has reached the excavation position, the behavior management unit 211 causes the wheel loader 100 to perform excavation (step S1104). In traveling mode, the behavior management unit 211 compares the current position with the target position each time it acquires it from the positioning device 141. If the current position matches the target position, it determines that the wheel loader 100 has arrived at the excavation position. The behavior management unit 211 then sets the operation mode to excavation mode and transmits this to the action generation unit 213. In response to this, the action generation unit 213 generates and outputs various control signals to perform excavation.

[0073] When the excavation is completed, the behavior management unit 211 acquires the actual excavation amount (step S1105). Here, information on the live load of the bucket 121 is acquired from the load acquisition device 142, and this is used as the actual excavation amount.

[0074] Next, the behavior management unit 211 proceeds to loading processing. Specifically, first, a loading position is set to the target position (step S1106). The loading position is acquired from the work instruction 230 (loading position 234).

[0075] Then, the behavior management unit 211 acquires the target route (step S1107). Here, the behavior management unit 211 transmits the target position to the route planning unit 212. The route planning unit 212 uses the map data 220 to generate the target route using the current position and the target position.

[0076] For example, when performing work Ins01 of the work instruction 230, the current position is p8 in the map data 220. Furthermore, the loading position R1 is p6 in the map data 220. The target route 240a created in this case is as shown in FIG. 7(c). In this case, the route planning unit 212 creates a route that moves backward from point p8 via point p7 to point p9, and then moves forward via point p7 to point p6.

[0077] Furthermore, when performing work Ins02 of the work instruction 230, the robot moves from excavation position Q2 to loading position R2. In this case, the current position is p1 in the map data 220, and the target position is p2 in the map data. The target route 240b created in this case is as shown in FIG. 7(d). In this case, the route planning unit 212 creates a route that moves backward from point p1 via point p4 to point p5, and then moves forward via p4 and p3 to p2.

[0078] Next, the behavior management unit 211 calculates and sets an excavation volume upper limit WBmax and an excavation volume lower limit WBmin (step S1108). The behavior management unit 211 calculates the excavation volume upper limit WBmax based on the excavation volume upper and lower limit data 510 in accordance with the target excavation volume WB. The behavior management unit 211 also calculates the route distance L1 using the target route and map data 220. Then, the behavior management unit 211 calculates the excavation volume lower limit WBmin based on the excavation volume upper and lower limit data 510 in accordance with the target excavation volume WB and the route distance L1.

[0079] The calculation of the excavation volume upper limit WBmax and the excavation volume lower limit WBmin is not limited to this timing, but may be performed between the setting of the target excavation volume WB and the determination of the adequacy of the excavation volume, which will be described later.

[0080] Thereafter, the behavior management unit 211 determines whether the actual excavation amount is within the allowable excavation amount range (step S1109). The allowable excavation amount range is between the upper excavation amount limit WBmax and the lower excavation amount limit WBmin (less than the upper excavation amount limit and greater than or equal to the lower excavation amount limit).

[0081] If it is within the allowable range (S1109; Yes), the behavior management unit 211 controls the wheel loader 100 to move to the loading position (step S1121). Here, the behavior management unit 211 sets the operation mode of the wheel loader 100 to a traveling mode and transmits this to the behavior generation unit 213. Also, the path planning unit 212 transmits the generated target path to the behavior generation unit 213. The behavior generation unit 213 generates and outputs various control signals to cause the wheel loader 100 to travel along the target path to the target position.

[0082] Once the wheel loader 100 has moved to the loading position, the behavior management unit 211 causes the wheel loader 100 to start loading (step S1122). Each time the behavior management unit 211 acquires the current position from the positioning device 141, it compares it with the target position, and if the current position matches the target position, it determines that the wheel loader 100 has arrived at the loading position. Then, it sets the operation mode to loading mode and transmits this to the operation generation unit 213. In response to this, the operation generation unit 213 generates and outputs various control signals to perform loading.

[0083] When loading is completed, the behavior management unit 211 updates the target excavation volume WB (step S1123). Here, the behavior management unit 211 adds the actual excavation volume acquired in step S1106 to the already loaded volume WA to update the already loaded volume WA. Then, the remaining loading volume WR is calculated, and compared with the standard excavation volume WS using the above method to calculate a new target excavation volume WB.

[0084] Thereafter, the behavior management unit 211 determines whether the new target excavation volume WB is 0 or not (step S1124).

[0085] If the target excavation amount WB is not 0 (step S1124; No), excavation and loading are still required, so the process proceeds to step S1101.

[0086] On the other hand, if the target excavation volume WB is 0 (step S1124; Yes), it is determined that loading is complete, and the process ends.

[0087] Next, in step S1109, if the excavation amount is outside the excavation amount allowable range (S1109; No), the behavior management unit 211 proceeds to soil release processing.

[0088] Specifically, the behavior management unit 211 first determines whether or not the excavation amount is insufficient (step S1131). Here, it determines whether or not the actual excavation amount is less than the excavation amount lower limit WBmin.

[0089] If the actual excavation amount is less than the excavation amount lower limit WBmin (S1131; Yes; excavation amount is insufficient), the behavior management unit 211 notifies the user to excavate again (step S1132). Here, a message indicating that excavation will be performed again is generated and sent to the user interface 190 as notification information.

[0090] Thereafter, the behavior management unit 211 causes the wheel loader 100 to perform the soil discharge process (step S1134), and proceeds to step S1101. During the soil discharge process, the behavior management unit 211 sets the operation mode to the soil discharge mode and sends this to the action generation unit 213. In response to this, the action generation unit 213 generates and outputs various control signals to perform soil discharge.

[0091] Since the wheel loader 100 excavates while raising the tip of the bucket 121, the bucket 121 must be lowered when excavating again. At this time, the bucket 121 is moved backward once to lower it so that it does not hit the object to be excavated. Therefore, when excavating again, the process proceeds to step S1101 to return (move) to a position where excavation can be performed again, and the process of setting the excavation position to the target position is repeated again.

[0092] On the other hand, if the actual excavation volume is not less than the excavation volume lower limit WBmin (S1131; No), that is, if it is equal to or greater than the excavation volume upper limit WBmax (excavation volume is excessive), the process of step S1132 is not performed and the process proceeds to step S1133. This is because when the excavation volume is insufficient, there is a possibility that the excavation target itself is insufficient, whereas when the excavation volume is excessive, there is no need to worry about this. For this reason, the user is only warned when the excavation volume is insufficient. However, even when the excavation volume is excessive, the user may be notified to excavate again.

[0093] As described above, the control system 180 for the wheel loader 100 of this embodiment has an automatic driving control device 200 that controls the operation of the wheel loader 100, which has the bucket 121 as a work implement, and a load acquisition device 142 that measures the load of an object in the bucket 121. The automatic driving control device 200 has a behavior management unit 211 that sets a target position to which the wheel loader 100 is to move, and the behavior management unit 211 determines the target position in accordance with the load acquired by the load acquisition device 142.

[0094] Therefore, according to this embodiment, when automatically excavating an excavation object, transporting it to a target position, and loading it, the wheel loader 100 can be controlled to take appropriate action according to the load (excavation amount) in the bucket 121.

[0095] For example, if the load is within a predetermined excavation tolerance range, the target position is set as the loading position, and if it is outside the tolerance range, the target position is set as the soil dumping position. This allows the soil to be dumped and excavated again if the excavation amount is too much or too little.

[0096] Furthermore, in this embodiment, the value of the excavation volume lower limit WBmin, which determines the allowable excavation range, is changed according to the route distance L1, which is the distance between the excavation position and the loading position. Specifically, the shorter the route distance L1, the smaller the value of the excavation volume lower limit WBmin. As a result, according to this embodiment, the wheel loader 100 can be controlled to operate optimally according to the traveling distance.

[0097] <Variation 1> In the above embodiment, the behavior management unit 211 controls the work so that soil is released and excavation is resumed at the excavation position specified in the work instruction 230 even if the actual excavation volume is less than the excavation volume lower limit WBmin, but this is not limited to this.

[0098] For example, if the actual excavation volume is less than the excavation volume lower limit WBmin, the behavior management unit 211 notifies the user. The user may receive this notification and change the excavation position as necessary. For example, this may occur if there are not enough excavation targets at the excavation position. In this case, in step S1101, the excavation position newly set by the user is set as the target position.

[0099] <<Second embodiment>> Next, a second embodiment of the present invention will be described. In this embodiment, the excavation amount lower limit WBmin is changed depending on the number of times excavation is repeated due to an insufficient excavation amount. Below, this embodiment will be described, focusing on the configuration different from the first embodiment.

[0100] The configuration of the wheel loader 100, the configuration of its control system 180, and the hardware configuration and functional blocks of the automatic driving control device 200 of this embodiment are the same as those of the first embodiment. However, the processing of the behavior management unit 211 is different.

[0101] The behavior management unit 211 of this embodiment counts the number of times re-excavation is performed due to an insufficient excavation amount (the number of re-excavations). Furthermore, the greater the number of re-excavations, the smaller the excavation amount lower limit WBmin is set. This is because repeated re-excavations due to an insufficient excavation amount may be caused by a decrease in the number of objects that can be excavated. In this way, by correcting the excavation amount lower limit WBmin, it is possible to avoid repeated, unnecessary excavation even when the number of excavation objects decreases and it becomes difficult to ensure the excavation amount.

[0102] Specifically, when calculating the excavation amount lower limit, the behavior management unit 211 first determines the excavation amount lower limit WBmin as a lower limit candidate according to the path distance L1, as in the first embodiment. Then, according to a predetermined rule, the lower limit candidate is processed so that the greater the number of re-excavations, the smaller the value becomes, and a corrected excavation amount lower limit WBmin1 is calculated. For example, the lower limit candidate is multiplied by a coefficient corresponding to the number of re-excavations to determine the corrected excavation amount lower limit WBmin1. The coefficient is determined so that the greater the number of re-excavations, the smaller the corrected excavation amount lower limit WBmin1 becomes.

[0103] An example of the relationship between the number of re-digging times and the corrected excavation amount lower limit WBmin1 is shown in Fig. 10. This data is stored in advance as lower limit correction data 511 in the storage device 183 or the like.

[0104] The flow of behavior management processing by the automatic driving control device 200 in this embodiment will be described. FIG. 11 shows the processing flow of behavior management processing in this embodiment. It is assumed that the current position is acquired from the positioning device 141 at predetermined time intervals. In the following processing, the automatic driving control device 200 uses the latest current position acquired at that time. The following description will focus on the differences from the flow of behavior management processing in the first embodiment.

[0105] First, when a work instruction is acquired, the behavior management unit 211 first sets an initial target excavation volume WB and a loading volume lower limit WTmin, and initializes a counter n (n is an integer equal to or greater than 1) that counts the number of re-excavation attempts (step S2100). Here, the counter n is set to 1.

[0106] Next, the behavior management unit 211 sets an excavation position as a target position (step S1101), and then acquires a target route (step S1102).

[0107] Thereafter, the behavior management unit 211 controls the wheel loader 100 to move to the excavation position (step S1103). Once moved to the excavation position, the behavior management unit 211 causes the wheel loader 100 to perform excavation (step S1104). Once excavation is completed, the behavior management unit 211 acquires the actual excavation volume (step S1105).

[0108] Next, the behavior management unit 211 proceeds to loading processing. Specifically, first, a loading position is set to a target position (step S1106). Then, the behavior management unit 211 acquires a target route (step S1107). Then, the behavior management unit 211 calculates and sets an upper excavation volume limit WBmax and a lower excavation volume limit WBmin (step S1108).

[0109] Next, in this embodiment, the behavior management unit 211 corrects the excavation volume lower limit WBmin according to the number of re-excavations (step S2103). Here, the correction is made in accordance with count lower limit correspondence data, which is defined so that the greater the number of re-excavations, the smaller the value of the excavation volume lower limit WBmin. Then, the behavior management unit 211 obtains the corrected excavation volume lower limit WBmin1. Thereafter, the behavior management unit 211 determines whether the actual excavation volume is within the allowable range of the excavation volume (step S1109). The allowable range of the excavation volume is between the excavation volume upper limit WBmax and the corrected excavation volume lower limit WBmin1.

[0110] If it is within the allowable range (S1109; Yes), the behavior management unit 211 controls the wheel loader 100 to move to the loading position (step S1121). Once moved to the loading position, the behavior management unit 211 causes the wheel loader 100 to start loading (step S1122). Once loading is complete, the behavior management unit 211 updates the target excavation volume (step S1123). Thereafter, the behavior management unit 211 determines whether the target excavation volume is 0 or not (step S1124).

[0111] If the target excavation volume is not 0 (step S1124; No), excavation and loading are still required, so the process proceeds to step S1101. On the other hand, if the target excavation volume is 0 (step S1124; Yes), it is determined that loading is complete, and the process ends.

[0112] Next, in step S1109, if the excavation amount is outside the excavation amount allowable range (S1109; No), the behavior management unit 211 proceeds to soil release processing.

[0113] Specifically, the behavior management unit 211 first determines whether the excavation amount is insufficient (step S1131). If the actual excavation amount is less than the corrected excavation amount lower limit WBmin1 (S1131; Yes; excavation amount insufficient), the behavior management unit 211 first increments the number of re-excavations. Specifically, the counter is incremented by 1 (step S2131). Thereafter, the behavior management unit 211 notifies the user of the re-excavation (step S1132). Thereafter, the behavior management unit 211 causes the wheel loader 100 to perform soil discharge processing (step S1133), and proceeds to step S1101.

[0114] On the other hand, if the actual excavation amount is not less than the corrected excavation amount lower limit WBmin1 (S1131; No), that is, if it is equal to or greater than the excavation amount upper limit WBmax (excessive excavation amount), the processes of steps S2131 and S1132 are not performed, and the process proceeds to step S1133.

[0115] This is because when the excavation amount is insufficient, there is a possibility that the excavation target itself is insufficient, so a notification is sent to alert the user. On the other hand, when the excavation amount is excessive, there is no need to worry about this. However, even when the excavation amount is excessive, the user may be notified to excavate again.

[0116] As described above, in the construction machine control system 180 of this embodiment, the behavior management unit 211 further repeatedly controls the construction machine to release the excavated object and excavate it again when the live load (excavation amount) is less than the excavation amount lower limit WBmin, and the more times this is repeated, the smaller the value of the excavation amount lower limit is set to.

[0117] Therefore, according to this embodiment, even when the number of excavation objects themselves is reduced and there is a high possibility that an insufficient excavation amount has occurred, the wheel loader 100 can be controlled to take appropriate action.

[0118] <Variation 2> In this embodiment, as in the first embodiment, when re-excavation is required due to an insufficient excavation amount, the user may be configured to be able to change the excavation position.

[0119] <Variation 3> In this embodiment, as in the first embodiment, the shorter the path distance L1, the smaller the excavation amount lower limit WBmin is set, and the greater the number of re-excavations, the larger the excavation amount lower limit WBmin is set, but this is not limiting. For example, the excavation amount lower limit WBmin may change depending only on the number of re-excavations, regardless of the path distance L1.

[0120] <Other variations> In addition, in the above embodiments, the lower limit margin is described as decreasing continuously and monotonically according to the path distance L1, but the change in the lower limit margin is not limited to this. For example, the lower limit margin may decrease stepwise every predetermined distance. The change in the lower limit margin according to the number of re-excavation attempts may also be stepwise.

[0121] Furthermore, although the upper limit margin and the lower limit margin are determined as percentages of the target excavation volume WB, they are not limited to this and may be determined as absolute amounts.

[0122] In addition, in each of the above embodiments, the actual excavation amount obtained immediately after excavation is added directly to the loading amount, but this is not limited to this. For example, just before loading, live load information may be obtained again from the load acquisition device 142, and the value may be added to calculate the already loaded amount WA.

[0123] Furthermore, in the above-described embodiments, the case where the soil release position is set to the same position as the excavation position has been described as an example, but this is not limiting. The soil release position may be set to a position different from the excavation position. In this case, when the excavation amount is excessive or insufficient and soil release is to be performed, the soil release position is set to the target position, and the robot travels to the soil release position and then releases the soil. After releasing the soil, the robot again sets the excavation position to the target position and returns to the excavation position.

[0124] Furthermore, in each of the above embodiments, the work instructions 230 have been described as being input by a user via the user interface 190, but the acquisition of these instructions is not limited to this. For example, the automatic driving control device 200 may be provided with a receiving unit, and the instructions may be received directly via the receiving unit. The receiving unit is realized by the communication I / F 185. In this case, the work instructions are created by a computer (management device) provided in a management center or the like, and transmitted to the automatic driving control device 200.

[0125] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments and includes various modifications. For example, while the above-described embodiments apply the present invention to a wheel loader, the application of the present invention is not limited to this and can also be applied to work machines other than wheel loaders, such as hydraulic excavators. Furthermore, the above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to those having all of the configurations described.

[0126] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the gist of the present invention. The present invention covers all technical matters included in the technical ideas described in the claims. The above-described embodiments are preferred examples, but a person skilled in the art can realize various alternatives, modifications, variations, or improvements from the contents disclosed in this specification, and these are included in the technical scope described in the appended claims. [Explanation of symbols]

[0127] 100: Work machine (wheel loader), 110: Body, 111: Engine, 112: Steering cylinder, 113: Drive force transmission device, 114: Hydraulic pump, 115: Control valve, 120: Work machine, 121: Bucket, 122: Lift arm, 123: Bell crank, 124: Bucket link, 125: Lift cylinder, 126: Bucket cylinder, 131: Tire, 131FL: Front left tire, 131FR: Front right tire, 131RL: Rear left Tire, 131RR: rear right tire, 132C: center joint, 133F: brake, 133R: brake, 134F: front differential, 134R: rear differential, 141: positioning device, 142: load acquisition device, 150: engine control device, 160: hydraulic control device, 170: driving control device, 180: control system, 181: CPU, 182: memory, 183: storage device, 184: input / output I / F, 185: communication I / F, 190: user interface, 200: Automatic driving control device, 211: Action management unit, 212: Route planning unit, 213: Action generation unit, 220: Map data, 221: Point, 222: Coordinates, 223: Attribute, 224: Line segment, 225: End point, 226: End point, 230: Work instruction, 231: ID, 232: Type, 233: Target loading amount, 234: Loading position, 235: Excavation position, 236: Discharge position, 240: Target route, 240a: Target route, 240b: Target route, 241: Passing point, 242: FNR, 300: working area, 310: excavation target, 320: loading target, 510: upper and lower limit data of excavation volume, 511: lower limit correction data, 520: lower limit data of loading volume, WA: Amount already loaded, WB: Target excavation volume, WBmax: Upper limit of excavation volume, WBmin: Lower limit of excavation volume, WBmin1: Lower limit of excavation volume after correction, WR: Remaining loading volume, WS: Standard excavation volume, WT: Target loading volume, WTmin: Lower limit of loading volume

Claims

1. an automatic driving control device that controls the operation of a work machine having a work implement; a load acquisition device that measures the load of an object in the work tool; a positioning device that acquires the current position of the work machine, The automatic driving control device includes: a behavior management unit that sets a target position to which the work machine is to be moved; a route planning unit that generates a target route, which is a travel route between the current position acquired by the positioning device and the target position set by the behavior management unit; a movement generating unit that generates a control signal for operating the work machine in accordance with the target path generated by the path planning unit; Equipped with the behavior management unit determines the target position in accordance with the live load acquired by the load acquisition device; the operation generating unit generates a control signal to cause the work machine to travel to the target position and load the object in the work implement onto a loading target. A control system for a work machine comprising:

2. 2. A work machine control system according to claim 1, The behavior management unit calculates a target live load based on a predetermined target live load for the loading object and a capacity of the working tool, and when the live load is less than an upper limit value and equal to or greater than a lower limit value predetermined as the target live load, sets a loading position where the loading object is located as the target position. A control system for a work machine comprising:

3. 2. A work machine control system according to claim 1, The behavior management unit calculates a target live load based on a predetermined target live load for a loading object and a capacity of the work tool, and when the live load is equal to or greater than a predetermined upper limit value for the target live load, sets a predetermined soil release position as the target position; The operation generation unit generates a control signal to cause the work machine to travel to the target position and to release the object in the work tool at the target position. A control system for a work machine comprising:

4. 2. A work machine control system according to claim 1, The behavior management unit calculates a target live load based on a predetermined target live load for a loading object and a capacity of the work tool, and when the live load is less than a predetermined lower limit value as the target live load, sets a predetermined soil release position as the target position; The operation generation unit generates a control signal to cause the work machine to travel to the target position and to release the object in the work tool at the target position. A control system for a work machine comprising:

5. 5. A work machine control system according to claim 4, When the load of the object in the work tool excavated at a predetermined first excavation position is less than the lower limit value and an operation of releasing the object in the work tool at the target position is executed, the behavior management unit sets a second excavation position different from the first excavation position as the target position. A control system for a work machine comprising:

6. 5. A work machine control system according to claim 4, the operation generating unit generates a travel control signal and a hydraulic control signal for loading an object into the work tool at a predetermined excavation position; The behavior management unit determines the lower limit value according to a route distance that is a distance from the excavation position to a loading position where the loading object is located. A control system for a work machine comprising:

7. 7. A work machine control system according to claim 6, The behavior management unit sets the lower limit value to a smaller value as the path distance becomes shorter. A control system for a work machine comprising:

8. A work machine control system according to claim 4 or 6, When the live load is less than the lower limit value, the behavior management unit repeatedly controls the work machine to release the excavated object and excavate it again, and the more times the repetition is performed, the smaller the lower limit value is set. A control system for a work machine comprising:

9. A control system for a work machine according to any one of claims 2 to 8, The behavior management unit sets the target live load to the smaller value of a value obtained by subtracting the load after loading onto the loading target from the target live load and the capacity of the work tool. A control system for a work machine comprising:

10. A work machine equipped with the work machine control system according to any one of claims 1 to 9.

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