Hydraulic shovel control system and hydraulic shovel control method

Abstract

A hydraulic shovel control system according to an embodiment of the present invention is for a hydraulic shovel including a bucket, and comprises a processing circuit. The processing circuit involves dividing terrain data relating to an excavation area (80), which can be excavated without moving the hydraulic shovel, into a plurality of areas (9) arranged in a lattice shape, and calculating the average ground surface height of each of the areas (9). When deviation between the minimum value and the maximum value of the average ground surface heights of the areas (9) is smaller than a prescribed value, the processing circuit determines an excavation procedure such that the bucket will pass through all the areas (9). When the deviation is larger than the prescribed value, the processing circuit determines an excavation procedure such that the bucket will pass through at least one area (9) that, among the areas (9), is relatively high in the average ground surface height.

Description

Hydraulic excavator control system and hydraulic excavator control method

[0001] The present disclosure relates to a hydraulic excavator control system and a hydraulic excavator control method.

[0002] Hydraulic excavators have been used for excavation work for some time. A hydraulic excavator includes a rotating body, a boom that moves up and down relative to the rotating body, an arm swingably connected to the tip of the boom, and a bucket swingably connected to the tip of the arm.

[0003] For example, Patent Document 1 describes a method for excavation work using a hydraulic excavator, in which an excavation site is divided into excavation zones arranged in a grid pattern and the order in which each excavation zone is to be excavated is determined. For example, the excavation order is determined so that the excavation zone starts from the excavation zone on the same side as the driver's seat of the hydraulic excavator and goes to the excavation zone on the opposite side, and also goes from the excavation zone at a higher position to the excavation zone at a lower position.

[0004] Japanese Patent Application Publication No. 11-247230

[0005] In the method for determining the excavation sequence in Patent Document 1, the "order from the highest excavation area to the lowest excavation area" is presumably based on the assumption that the excavation site is generally sloped. In contrast, in actual terrain, each excavation area has unevenness. Therefore, it is desirable to determine an appropriate excavation procedure that matches the terrain shape.

[0006] Therefore, an object of the present disclosure is to provide a hydraulic excavator control system and a hydraulic excavator control method that can determine an appropriate excavation procedure in accordance with the shape of the terrain.

[0007] From one aspect, the present disclosure provides a control system for a hydraulic excavator including a bucket, the control system comprising a processing circuit, wherein the processing circuit is configured to divide topographical data of an excavation area that can be excavated without movement of the hydraulic excavator into a plurality of areas arranged in a grid pattern, calculate an average ground surface height for each of the plurality of areas, and, if a deviation between a minimum value and a maximum value of the average ground surface heights for the plurality of areas is smaller than a predetermined value, determine an excavation procedure such that the bucket passes through all of the areas, and, if the deviation is larger than the predetermined value, determine an excavation procedure such that the bucket passes through at least one area of ​​the plurality of areas that has a relatively high average ground surface height.

[0008] From another aspect, the present disclosure provides a control method for a hydraulic excavator including a bucket, the control method comprising: dividing topographical data of an excavation area that can be excavated without the hydraulic excavator moving into a plurality of areas arranged in a grid pattern; calculating an average ground surface height for each of the plurality of areas; and, if the deviation between the minimum and maximum values ​​of the average ground surface heights for the plurality of areas is smaller than a predetermined value, determining an excavation procedure such that the bucket passes through all of the areas; and, if the deviation is larger than the predetermined value, determining an excavation procedure such that the bucket passes through at least one area of ​​the plurality of areas that has a relatively high average ground surface height.

[0009] According to the present disclosure, a hydraulic excavator control system and a hydraulic excavator control method are provided that are capable of determining an appropriate excavation procedure in accordance with the shape of the terrain.

[0010] FIG. 1 is a schematic side view of a hydraulic excavator. FIG. 2 is a diagram showing a hydraulic circuit incorporated in the hydraulic excavator. FIG. 3 is a schematic configuration diagram of a hydraulic excavator control system according to an embodiment. FIG. 4 is a flowchart showing the process performed by a processing circuit of the control system when determining an excavation procedure. FIG. 5 is a plan view showing an excavation area divided into a plurality of areas. FIGS. 6A and 6B are diagrams showing an example of a first step of the excavation procedure. FIGS. 7A to 7C are diagrams showing an example of a second step of the excavation procedure. FIGS. 8A and 8B are diagrams showing excavation areas of modified examples.

[0011] Fig. 1 shows a hydraulic excavator 1, and Fig. 3 shows a control system 4 for the hydraulic excavator 1. The hydraulic excavator 1 includes a traveling body 11, a rotating body 12 rotatably supported on the traveling body 11, a boom 13 that moves up and down relative to the rotating body 12, an arm 14 swingably connected to the tip of the boom 13, and a bucket 15 swingably connected to the tip of the arm 14. In this embodiment, the traveling body 11 includes a pair of crawlers, but the traveling body 11 may also include a plurality of wheels.

[0012] 2 , the hydraulic excavator 1 further includes travel motors 31, 32 that drive the pair of crawlers, respectively, a swing motor 33 that swings the swing body 12, a boom cylinder 34 that raises and lowers the boom 13, an arm cylinder 35 that swings the arm 14, and a bucket cylinder 36 that swings the bucket 15. These hydraulic actuators, together with the pump device 21, constitute the hydraulic circuit 2. More specifically, the pump device 21 is connected to a valve unit 22, and the valve unit 22 is connected to the hydraulic actuators.

[0013] In this embodiment, the pump device 21 includes a variable displacement hydraulic pump 21a with a variable tilt angle, and a regulator 21b that changes the tilt angle of the hydraulic pump 21a. For example, the hydraulic pump 21a is an axial piston swash plate pump or bent axis pump. The hydraulic pump 21a is driven by an engine or an electric motor mounted on the hydraulic excavator 1. In this embodiment, the discharge flow rate of the pump device 21 is controlled by an electric positive control system. However, the discharge flow rate of the pump device 21 may also be controlled by another system, such as a hydraulic negative control system or a load sensing system.

[0014] The valve unit 22 includes two travel control valve devices 23, 24, a swing control valve device 25, a boom control valve device 26, an arm control valve device 27, and a bucket control valve device 28. The two travel control valve devices 23, 24 control the flow of hydraulic oil supplied from the pump device 21 to the travel motors 31, 32, respectively. The swing control valve device 25 controls the flow of hydraulic oil supplied from the pump device 21 to the swing motor 33. The boom control valve device 26 controls the flow of hydraulic oil supplied from the pump device 21 to the boom cylinder 34. The arm control valve device 27 controls the flow of hydraulic oil supplied from the pump device 21 to the arm cylinder 35. The bucket control valve device 28 controls the flow of hydraulic oil supplied from the pump device 21 to the bucket cylinder 36.

[0015] Each of the control valve devices 23 to 28 may include, for example, a pilot-operated spool valve and a pair of electromagnetic proportional valves that output pilot pressure to the spool valve. In this case, the valve unit 22 includes a housing, a plurality of spools slidably held in the housing, and a plurality of electromagnetic proportional valves attached to the housing corresponding to a plurality of pilot chambers formed in the housing. The housing may be a single block or may be divided into a plurality of blocks. Alternatively, each of the control valve devices 23 to 28 may be an electromagnetic spool valve.

[0016] 3 , the control system 4 for the hydraulic excavator 1 includes a plurality of attitude angle sensors 5, an external sensor 6, and a controller 7. The controller 7 controls the above-mentioned pump device 21 and control valve devices 23 to 28. The attitude angle sensor 5, the external sensor 6, the pump device 21, and the control valve devices 23 to 28 are connected to the controller 7 by wire or wirelessly. Note that if the pump device 21 is controlled by a hydraulic negative control method or a load sensing method, the pump device 21 does not need to be controlled by the controller 7.

[0017] The attitude angle sensor 5 detects the attitude of the hydraulic excavator 1 as attitude information. In this embodiment, the attitude angle sensor 5 includes a vehicle body attitude angle sensor 51, a swing attitude angle sensor 52, a boom attitude angle sensor 53, an arm attitude angle sensor 54, and a bucket attitude angle sensor 55.

[0018] The external sensor 6 is attached to the revolving unit 12. As shown in Fig. 5 , the external sensor 6 measures the topography of an excavation area 80 that is located in front of the revolving unit 12 at the excavation site 8 and that can be excavated by the hydraulic excavator 1 without moving, and acquires topography data for the excavation area 80. The excavation area 80 is an area that can be excavated by a combination of swinging and pulling the bucket 15 (the pulling operation of the bucket 15 is achieved by movements of the bucket 15, arm 14, and boom 13) while the hydraulic excavator 1 is positioned in a fixed position. In this embodiment, the contour of the excavation area 80 is rectangular.

[0019] The topographical data is a collection of point data indicating three-dimensional coordinates at grid positions at predetermined intervals (for example, 10 cm) in the excavation area 80. The external sensor 6 is, for example, a LiDAR (Light Detection And Ranging) or a stereo camera.

[0020] 3, the controller 7 includes a processing circuit 70. The processing circuit 70 acquires attitude information from the plurality of attitude angle sensors 5 and acquires terrain data from the external sensor 6, and generates a control command to be output to a controlled object based on the acquired attitude information and terrain data.

[0021] The processing circuit 70 includes a processor 71, a system memory 72, and a storage memory 73. The processor 71 may include a CPU. The system memory 72 may include a RAM. The storage memory 73 may include a hard disk, a flash memory, or a combination thereof. The storage memory 73 stores a program 73a.

[0022] The controller 7 may include at least one user interface 74. The user interface 74 may be located in the cockpit. For example, the user interface 74 includes an input interface and an output interface. For example, the input interface may be a touch panel, a steering wheel, a lever, a switch, or the like. For example, the output interface may be a display.

[0023] The controller 7 may include at least one communication interface 75. The communication interface 75 includes an interface that communicatively connects an external device to the controller 7 via a wired or wireless connection. The communication interface 75 may include an interface that communicatively connects to a communication network such as the Internet via a wired or wireless connection.

[0024] In this embodiment, an automatic excavation program is included in the programs 73a stored in the storage memory 73. The automatic excavation program is a program for causing the hydraulic excavator 1 to perform excavation work by automatic operation, and the automatic excavation program read from the storage memory 73 is executed by the processor 71, whereby the processing circuit 70 executes the automatic excavation process.

[0025] In this embodiment, the processing circuitry 70 determines an excavation procedure for each excavation area 80 shown in Fig. 5. Fig. 4 is a flowchart showing the process performed by the processing circuitry 70 when determining an excavation procedure.

[0026] First, the processing circuit 70 divides the topographical data of the excavation area 80 acquired from the external sensor 6 into a plurality of areas 9 arranged in a grid pattern (step S1). When the direction from the excavation area 80 toward the hydraulic excavator 1 is defined as the vertical direction and the direction perpendicular to the vertical direction is defined as the horizontal direction, the number of areas 9 in the vertical and horizontal directions can be determined appropriately. In this embodiment, the number of areas 9 in the vertical direction is three and the number of areas 9 in the horizontal direction is three.

[0027] The vertical length L of each area 9 is smaller than the maximum excavation distance of the hydraulic excavator 1, and the horizontal width W of each area 9 is equal to or smaller than the width Wb of the bucket 15 of the hydraulic excavator 1. For example, the vertical length L of each area 9 is half the maximum excavation distance of the hydraulic excavator 1, and the horizontal width W of each area 9 is equal to the width Wb of the bucket 15. In FIG. 4 , the horizontal width W of each area 9 is approximately two-thirds the width Wb of the bucket 15.

[0028] Next, the processing circuit 70 calculates the average ground surface height H for each of the plurality of areas 9 (step S2). That is, the average ground surface height H for each area 9 is calculated by dividing the sum of the height coordinates of the point data for that area 9 by the number of point data.

[0029] Thereafter, the processing circuit 70 calculates the deviation ΔH (=Hmax-Hmin) between the maximum value Hmax and the minimum value Hmin of the average ground surface height H of the multiple areas 9 that make up the excavation region 80, and compares the calculated deviation ΔH with a predetermined value V (step S3). The predetermined value V is an index for determining whether the excavation region 80 has few or many irregularities. For example, the predetermined value V is a value in the range of 50 cm to 100 cm.

[0030] If the deviation ΔH is smaller than the predetermined value V (NO in step S3), the processing circuit 70 determines the excavation procedure to be the first procedure, and if the deviation ΔH is larger than the predetermined value V (YES in step S3), the processing circuit 70 determines the excavation procedure to be the second procedure. Note that although in FIG. 4 the process proceeds to step S4 when ΔH=V, it may also proceed to step S5 when ΔH=V.

[0031] When the deviation ΔH is smaller than the predetermined value V, in other words, when there are few irregularities in the excavation area 80, the first procedure is a procedure in which the bucket 15 passes through all areas 9, as shown in Figures 6A and 6B. More specifically, the bucket 15 is pulled while swinging along vertical line 81 shown in Figure 6A, and the bucket 15 is pulled while swinging along vertical line 82 shown in Figure 6B. Note that if the bucket 15 can pass through all areas 9 simply by pulling the bucket 15 at a plurality of swing positions, there is no need to pull the bucket 15 while swinging.

[0032] In this embodiment, as shown by hatching in Fig. 6A , when the bucket 15 is pulled while swinging along the vertical line 81, the entire areas 91, 94, and 98 in the left row and approximately two-thirds of the left side of the areas 92, 95, and 98 in the center row are excavated. Also, as shown by hatching in Fig. 6B , when the bucket 15 is pulled while swinging along the vertical line 82, the entire areas 93, 97, and 99 in the right row and approximately one-third of the right side of the areas 92, 95, and 98 in the center row are excavated (approximately the central one-third has already been excavated in the previous operation). Note that the pulling operation of the bucket 15 along the vertical line 82 may be performed first, and then the pulling operation of the bucket 15 along the vertical line 81 may be performed thereafter.

[0033] When the deviation ΔH is greater than the predetermined value V, in other words, when the excavation area 80 is significantly uneven, the second procedure is a procedure in which the bucket 15 passes through at least one area 9 among the areas 9 in which the average ground surface height H is relatively high, as shown in Figures 7A to 7C. For example, the areas 9 in which the average ground surface height H is relatively high are the rear area 91 of the left column, the middle and front areas 95 and 98 of the center column, and the middle area 96 of the right column. In this case, the bucket 15 is pulled while swinging along the vertical line 83 shown in Figure 7A, the bucket 15 is pulled without swinging along the vertical line 84 shown in Figure 7B, and the bucket 15 is pulled while swinging along the vertical line 85 shown in Figure 7C.

[0034] As shown by hatching in Figure 7A, when the bucket 15 is pulled while swinging along vertical line 83, the entire back area 91 of the left column and approximately two-thirds of the left side of the back area 92 of the center column are excavated. As shown by hatching in Figure 7B, when the bucket 15 is pulled along vertical line 84 without swinging, the entire middle and front areas 95, 98 of the center column, approximately one-third of the right side of the middle and front areas 94, 96 of the left column, and approximately one-third of the left side of the middle and front areas 96, 99 of the right column are excavated. As shown by hatching in Figure 7C, when the bucket 15 is pulled while swinging along vertical line 85, approximately two-thirds of the right side of the center area 96 of the right column are excavated (approximately one-third of the left side of area 96 and approximately two-thirds of the right side of the center area 95 of the center column have already been excavated in the previous operation). The pulling operation of the bucket 15 along the vertical lines 83 to 85 may be performed in any order.

[0035] 7A to 7C show an example in which four areas 91, 95, 96, and 98 are areas 9 with a relatively high average ground surface height H, but there may be only one area 9 with a relatively high average ground surface height H. In other words, the areas 9 with a relatively high average ground surface height H are selected in descending order of average ground surface height H from among the areas 9 with an average ground surface height H that is higher than the average value obtained by dividing the sum of the average ground surface heights H of all areas 9 by the number of areas 9. The number of areas 9 to be selected is determined appropriately depending on the excavation situation. Alternatively, if there are areas 9 with a relatively high average ground surface height H in the same category as the area 9 with the highest average ground surface height H, an excavation trajectory may be set in which the bucket 15 passes through all of those areas 9.

[0036] The processing circuit 70 drives the hydraulic excavator 1 to excavate the excavation area 80 in accordance with the determined excavation procedure. Specifically, the processing circuit 70 controls the pump device 21, the swing control valve device 25, the boom control valve device 26, the arm control valve device 27, and the bucket control valve device 28 so that the determined excavation procedure is executed. Thereafter, the processing circuit 70 repeats the processing of steps S1 to S5 described above for the adjacent excavation area 80.

[0037] As described above, in this embodiment, the excavation procedure for the excavation area 80 is determined based on the average ground surface height H of the multiple areas 9 that make up the excavation area 80, so it is possible to determine an appropriate excavation procedure that matches the shape of the terrain. This makes it possible to eliminate unnecessary excavation and improve construction efficiency. Note that improving construction efficiency means shortening the takt time or, if the hydraulic excavator 1 is equipped with an engine, reducing fuel consumption, etc.

[0038] Furthermore, the size of each area 9 is appropriately set because the vertical length L of each area 9 is smaller than the maximum excavation distance of the hydraulic excavator 1 and the horizontal width W of each area 9 is equal to or smaller than the width Wb of the bucket 15 of the hydraulic excavator 1. This makes it possible to formulate an operation plan that is optimal for the shape of the bucket 15. As a result, it is possible to obtain effects such as reducing the number of excavation operations and obtaining a clean construction surface.

[0039] Furthermore, since the hydraulic excavator 1 is driven to excavate the excavation area 80 in accordance with the determined excavation procedure, automatic operation can be performed with high construction efficiency.

[0040] <Modifications> The present disclosure is not limited to the above-described embodiment, and various modifications are possible without departing from the gist of the present disclosure.

[0041] For example, the control system 4 may include, in addition to the controller 7, a server capable of communicating with the controller 7 via a network, and the processing circuit of the server may function as the processing circuit 70 described above.

[0042] Furthermore, the control system 4 does not necessarily need to include the external sensor 6, and topographical data of the entire excavation site 8 may be stored in advance in the storage memory 73 of the controller 7. Alternatively, the processing circuit 70 may obtain topographical data of the entire excavation site 8 from a server via a network.

[0043] The contour of the excavation area 80 does not necessarily have to be rectangular. For example, the contour of the excavation area 80 may be a trapezoid with slanted horizontal sides as shown in Fig. 8A, or a trapezoid with slanted vertical sides as shown in Fig. 8B.

[0044] The functions of the elements disclosed herein can be performed using circuits or processing circuits, including general-purpose processors, special-purpose processors, integrated circuits, application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), conventional circuits, and / or combinations thereof, configured or programmed to perform the disclosed functions. Processors are considered processing circuits or circuits because they include transistors and other circuitry. In this disclosure, a circuit, unit, or means is hardware that performs the recited functions or hardware that is programmed to perform the recited functions. The hardware may be hardware disclosed herein or other known hardware that is programmed or configured to perform the recited functions. Where the hardware is a processor, which is considered a type of circuit, the circuit, means, or unit is a combination of hardware and software, and the software is used to configure the hardware and / or processor.

[0045] The program disclosed herein may be stored in a computer-readable storage medium. The storage medium is a non-transitory, tangible medium. The storage medium may be built into or external to a computer (e.g., a mobile information terminal, a personal computer, a server, etc.). The storage medium may include RAM, ROM, EEPROM, storage, etc., and may be, for example, a hard disk, a flash memory, an optical disk, etc. The program stored in the storage medium may be executed on a computer to which the storage medium is directly connected, or on a computer connected to the storage medium via a communication network (e.g., the Internet).

[0046] <Summary> In a first aspect, the present disclosure provides, from one aspect, a control system for a hydraulic excavator including a bucket, the hydraulic excavator control system being configured to divide topographical data of an excavation area that can be excavated without the hydraulic excavator moving into a plurality of areas arranged in a grid pattern, calculate an average ground surface height for each of the plurality of areas, and, if a deviation between a minimum value and a maximum value of the average ground surface heights for the plurality of areas is smaller than a predetermined value, determine an excavation procedure such that the bucket passes through all of the areas, and, if the deviation is larger than the predetermined value, determine an excavation procedure such that the bucket passes through at least one area of ​​the plurality of areas that has a relatively high average ground surface height.

[0047] According to the above configuration, the excavation procedure for the excavation area is determined based on the average ground surface height H of the multiple areas that make up the excavation area, so it is possible to determine an appropriate excavation procedure that matches the shape of the terrain. This makes it possible to eliminate unnecessary excavation and improve construction efficiency. Note that improving construction efficiency means shortening the takt time or, if the hydraulic excavator is equipped with an engine, reducing fuel consumption, etc.

[0048] As a second aspect, in the first aspect, when the direction from the excavation area toward the hydraulic excavator is defined as the vertical direction and the direction perpendicular to the vertical direction is defined as the horizontal direction, the length of each of the plurality of areas in the vertical direction may be shorter than the maximum excavation distance of the hydraulic excavator, and the width of each of the plurality of areas in the horizontal direction may be equal to or smaller than the width of the bucket. With this configuration, the size of each area is appropriately set, making it possible to create an operation plan that is optimal for the shape of the bucket. As a result, it is possible to achieve effects such as reducing the number of excavation operations and obtaining a clean construction surface.

[0049] As a third aspect, in the first or second aspect, the processing circuit may drive the hydraulic excavator so as to excavate the excavation area in accordance with the determined excavation procedure. With this configuration, automatic operation can be performed with high construction efficiency.

[0050] As a fourth aspect, in any of the first to third aspects, for example, the above-mentioned hydraulic excavator control system may further include an external sensor that measures the topography of the excavation area, and the processing circuit may acquire the topography data from the external sensor.

[0051] In a fifth aspect, from another aspect, the present disclosure provides a control method for a hydraulic excavator including a bucket, the hydraulic excavator control method comprising: dividing topographical data of an excavation area that can be excavated without movement of the hydraulic excavator into a plurality of areas arranged in a grid pattern; calculating an average ground surface height for each of the plurality of areas; and, if a deviation between a minimum value and a maximum value of the average ground surface heights for the plurality of areas is smaller than a predetermined value, determining an excavation procedure such that the bucket passes through all of the areas; and, if the deviation is larger than the predetermined value, determining an excavation procedure such that the bucket passes through at least one area of ​​the plurality of areas that has a relatively high average ground surface height.

[0052] According to the above configuration, the excavation procedure for the excavation area is determined based on the average ground surface height H of the multiple areas that make up the excavation area, so it is possible to determine an appropriate excavation procedure that matches the shape of the terrain. This makes it possible to eliminate unnecessary excavation and improve construction efficiency. Note that improving construction efficiency means shortening the takt time or, if the hydraulic excavator is equipped with an engine, reducing fuel consumption, etc.

[0053] As a sixth aspect, in the fifth aspect, when the direction from the excavation area toward the hydraulic excavator is defined as the vertical direction and the direction perpendicular to the vertical direction is defined as the horizontal direction, the length of each of the plurality of areas in the vertical direction may be shorter than the maximum excavation distance of the hydraulic excavator, and the width of each of the plurality of areas in the horizontal direction may be equal to or smaller than the width of the bucket. With this configuration, the size of each area is appropriately set, making it possible to create an operation plan that is optimal for the shape of the bucket. As a result, it is possible to achieve effects such as reducing the number of excavation operations and obtaining a clean construction surface.

[0054] As a seventh aspect, in the fifth or sixth aspect, the hydraulic excavator may be driven so as to excavate the excavation area in accordance with the determined excavation procedure. According to this configuration, automatic operation can be performed with high construction efficiency.

[0055] As an eighth aspect, in any one of the fifth to seventh aspects, the topography data may be acquired from an external sensor that measures the topography of the excavation area, for example.

Claims

1. A control system having a processing circuit for a hydraulic excavator including a bucket, wherein the processing circuit is configured to: divide topographical data of an excavation area that can be excavated without the hydraulic excavator moving into a plurality of areas arranged in a grid pattern; calculate the average ground surface height for each of the plurality of areas; and, if a deviation between a minimum and a maximum of the average ground surface heights of the plurality of areas is smaller than a predetermined value, determine an excavation procedure such that the bucket passes through all of the areas; and, if the deviation is larger than the predetermined value, determine an excavation procedure such that the bucket passes through at least one area among the plurality of areas in which the average ground surface height is relatively high.

2. The hydraulic excavator control system according to claim 1, wherein, when a direction from the excavation area toward the hydraulic excavator is defined as a vertical direction and a direction perpendicular to the vertical direction is defined as a horizontal direction, the vertical length of each of the plurality of areas is smaller than a maximum excavation distance of the hydraulic excavator, and the horizontal width of each of the plurality of areas is equal to or smaller than a width of the bucket.

3. The hydraulic excavator control system according to claim 1 or 2, wherein the processing circuit drives the hydraulic excavator to excavate the excavation area according to a determined excavation procedure.

4. A hydraulic excavator control system according to claim 1 or 2, further comprising an external sensor for measuring a topography of the excavation area, and wherein the processing circuit acquires the topography data from the external sensor.

5. A control method for a hydraulic excavator including a bucket, comprising: dividing topographical data of an excavation area that can be excavated without the hydraulic excavator moving into a plurality of areas arranged in a grid pattern; calculating an average ground surface height for each of the plurality of areas; determining an excavation procedure such that the bucket passes through all of the areas if the deviation between the minimum and maximum of the average ground surface heights for the plurality of areas is smaller than a predetermined value; and determining an excavation procedure such that the bucket passes through at least one area among the plurality of areas in which the average ground surface height is relatively high if the deviation is larger than the predetermined value.

6. A hydraulic excavator control method according to claim 5, wherein, when a direction from the excavation area toward the hydraulic excavator is defined as a vertical direction and a direction perpendicular to the vertical direction is defined as a horizontal direction, the vertical length of each of the plurality of areas is smaller than a maximum excavation distance of the hydraulic excavator, and the horizontal width of each of the plurality of areas is equal to or smaller than a width of the bucket.

7. A hydraulic excavator control method according to claim 5 or 6, further comprising driving said hydraulic excavator so as to excavate said excavation area in accordance with a determined excavation procedure.

8. A hydraulic excavator control method according to claim 5 or 6, further comprising acquiring the topographical data from an external sensor that measures the topography of the excavation area.

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