Work machine control system

Abstract

To provide a work machine control system enabling a plurality of work machines to efficiently work at a work site.SOLUTION: At a work site where a first work machine (1A) and a second work machine (1B) respectively work, a work machine control system (100) controls operation of at least the second work machine. The work machine control system has a control part (50) that generates a command signal to make the second work machine cooperatively operate according to movement of the first work machine so as to prevent the first work machine and the second work machine from interfering with each other. Characteristics information related to characteristics of a spring damper virtually set between a first specific site and a second specific site is used to generate the command signal.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a control system for a work machine. [Background technology]

[0002] Conventionally, there is known a work machine having a machine body and a work attachment supported on the machine body so as to be able to be raised or lowered. For example, the work attachment includes a boom, an arm, and a bucket. Patent Document 1 discloses a technology for automatically controlling such a work machine as an autonomous driving machine.

[0003] By applying such an automatic driving machine for a work machine to a work site, productivity can be improved. For example, the automatic driving machine can perform simple tasks such as operating in a predetermined area. As a result, the operator can free his / her hands to perform other tasks in parallel with the operation of the automatic driving machine. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2021-131004 A Summary of the Invention [Problem to be solved by the invention]

[0005] At many work sites, multiple work machines may operate in close proximity to each other when carrying soil or performing other tasks. If all of these work machines are operated by humans, they can operate each other without stopping their own work while watching the movements of the other work machines. However, an automated driving machine such as that described in Patent Document 1 operates according to a predetermined work plan, and therefore there is a possibility that the two may come into contact and interfere with each other if the surrounding work machines approach each other unexpectedly.

[0006] An object of the present invention is to provide a work machine control system that is capable of efficiently carrying out work using a plurality of work machines at a work site. [Means for solving the problem]

[0007] A first aspect of the present invention provides a work machine control system for controlling operation of at least a second work machine at a work site where a first work machine and a second work machine are working, the system including a control unit that generates a command signal for the second work machine to operate in coordination in accordance with movement of the first work machine so as to prevent at least one of interference between the first work machine and the second work machine and interference between tasks between the first work machine and the second work machine, the control unit determines, based on operation information relating to at least the movement of the first work machine, characteristic information relating to characteristics of a spring damper that is virtually set between the first specific portion and the second specific portion so as to be displaced in accordance with the distance between the first specific portion of the first work machine and the second specific portion of the second work machine, and control parameters for controlling the second work machine, and generates the command signal based on the determined characteristic information and control parameters.

[0008] According to this configuration, by optimizing the operation of the second working machine on the cooperative side, it is possible to carry out efficient work while preventing the machines from coming into contact with each other or preventing interference between the different works.

[0009] A control system according to a second aspect of the present invention may be the control system according to the first aspect described above, wherein the control unit determines the characteristic information and the control parameters based on the operation information and preset automatic stop information for stopping the movement of the second work machine.

[0010] According to this configuration, the characteristic information and control parameters are determined taking into consideration the stop information for stopping the movement of the second work machine in advance, so that interference between the first work machine and the second work machine can be prevented with a high degree of accuracy.

[0011] A control system according to a third aspect of the present invention is the control system according to the first or second aspect described above, further comprising a database that pre-stores reference operation information corresponding to a movement of the first work machine, reference characteristic information corresponding to the characteristic information, and reference control parameters corresponding to the control parameters in association with one another, and the control unit may input input information that is the current operation information of the first work machine to the database, identify the reference operation information corresponding to the input information, and generate the command signal using the reference characteristic information and the reference control parameter that correspond to the identified reference operation information.

[0012] According to this configuration, by extracting optimal control parameters and characteristic information from multiple data sets stored in the database, it is possible to prevent interference between the first work machine and the second work machine with a high degree of accuracy.

[0013] A control system according to a fourth aspect of the present invention is the control system according to any one of the first to third aspects described above, wherein the first work machine is operated and operated by an operator on board, or is operated by remote control, and the second work machine is operated by automatic control.

[0014] According to this configuration, even when the operator operates the first work machine from a remote location, there is no need to pay much attention to the movement of the second work machine, and both the first work machine and the second work machine can be efficiently operated while preventing interference between them. In particular, when the first work machine is remotely controlled, the database also stores the operator's characteristics together with the control parameters, etc., so that the second work machine can be coordinated to match the skill and operation characteristics of the current remote control operator. This allows the second work machine to operate in accordance with the skill, operation characteristics, and work pace of the remote control operator, improving the comfort of the operator during work. For example, the operator can work at his or her own pace and does not have to worry about the second work machine. Effect of the Invention

[0015] According to the present invention, a work machine control system is provided that is capable of efficiently carrying out work using a plurality of work machines at a work site. [Brief description of the drawings]

[0016] [Figure 1] 1 is a side view of a work machine according to an embodiment of the present invention. [Diagram 2] 1 is a schematic diagram showing a working site of a work machine according to an embodiment of the present invention; [Diagram 3] FIG. 2 is a diagram showing a work plan for a first work machine and a second work machine according to an embodiment of the present invention. [Figure 4] FIG. 2 is a block diagram of a control system according to an embodiment of the present invention. [Diagram 5] 5 is a schematic diagram illustrating a spring damper virtually set by the control system according to the embodiment of the present invention; FIG. [Figure 6] 4 is a flowchart of an overall process executed by a control system according to an embodiment of the present invention. [Figure 7] 4 is a flowchart for explaining details of a calculation process executed by a control system according to an embodiment of the present invention. [Figure 8] FIG. 2 is a schematic diagram of a calculation process executed by a control system according to an embodiment of the present invention. [Figure 9] FIG. 2 is a schematic diagram of a database of a control system according to an embodiment of the present invention. [Figure 10] 10 is a flowchart showing how the control system according to the embodiment of the present invention calculates characteristic information and control parameters. [Figure 11] 1 is a schematic diagram illustrating a turning operation of a work machine according to an embodiment of the present invention. FIG. [Figure 12] 13 is a flowchart showing how a control system according to another embodiment of the present invention calculates characteristic information and control parameters. [Figure 13]2 is a schematic diagram illustrating the movement of a work machine controlled by a control system according to an embodiment of the present invention. FIG. [Figure 14] 2 is a schematic diagram illustrating the movement of a work machine controlled by a control system according to an embodiment of the present invention. FIG. [Figure 15] 2 is a schematic diagram illustrating the movement of a work machine controlled by a control system according to an embodiment of the present invention. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[0018] 1 shows a side view of a hydraulic excavator 1 (working machine) according to a first embodiment of the present invention. The hydraulic excavator 1 includes a lower traveling body 10 (lower main body) capable of traveling on the ground G (traveling surface), an upper rotating body 12 (upper main body) rotatably supported on the lower traveling body 10, and a movable work attachment 20 (attachment) mounted on the upper rotating body 12. The lower traveling body 10 and the upper rotating body 12 correspond to the body of the hydraulic excavator 1.

[0019] The lower traveling body 10 is capable of traveling on the ground surface G. As an example, the lower traveling body 10 includes a crawler-type traveling unit.

[0020] The upper rotating body 12 has a rotating frame 121 supported by the lower traveling body 10, a cab 13 mounted on the rotating frame 121, and a counterweight 15. The cab 13 allows an operator (worker, operator) to board, and various devices for operating the hydraulic excavator 1 are disposed therein. The counterweight 15 is disposed at the rear portion of the rotating frame 121, and functions as a weight for balancing the hydraulic excavator 1.

[0021] The work attachment 20 is attached (supported) to the upper rotating body 12 so as to be movable relative to the upper rotating body 12, and performs a predetermined work on the ground or the like. The work attachment 20 includes a boom 21 connected to the front end of the revolving frame 121 so as to be rotatable in the hoisting direction about a horizontal central axis of rotation, an arm 22 connected to the tip of the boom 21 so as to be rotatable about the horizontal central axis of rotation, and a bucket 23 (tip attachment) connected to the tip of the arm 22 so as to be rotatable about the horizontal central axis of rotation. In this embodiment, the central axes of rotation of the boom 21, the arm 22, and the bucket 23 are set parallel to each other. The boom 21 and the arm 22 constitute a hoisting body of the hydraulic excavator 1. The hydraulic excavator 1 further includes a boom cylinder 21S that expands and contracts to hoist (rotate) the boom 21, an arm cylinder 22S that expands and contracts to rotate the arm 22, and a bucket cylinder 23S that expands and contracts to rotate the bucket 23. Each of these cylinders comprises a hydraulic cylinder.

[0022] Bucket 23 includes a plurality of teeth 23H (tips, claws). The plurality of teeth 23H are arranged at intervals in a direction perpendicular to the plane of FIG. 1 (left-right direction), and are provided so as to protrude from the main body of bucket 23. When hydraulic excavator 1 performs excavation work on ground surface G, work attachment 20 moves so that the plurality of teeth 23H of bucket 23 penetrates into the ground surface.

[0023] The cab 13 is mounted on the front of the rotating frame 121 and constitutes a driver's cab for operating the hydraulic excavator 1. In other words, within the cab 13, an operator can perform operations for running the lower traveling structure 10, rotating the upper rotating structure 12, and operating the work attachment 20. Note that, as will be described later, when the hydraulic excavator 1 is remotely operated or automatically controlled, it is not necessary for the operator to be in the cab 13.

[0024] FIG. 2 is a schematic diagram showing the state of a work site of the hydraulic excavator 1 according to this embodiment. FIG. 3 is a diagram showing the work plan of the α machine 1A (remotely controlled machine, first work machine) and the β machine 1B (automatically controlled machine, second work machine) according to this embodiment. In FIG. 3, each work content and its start time are respectively shown. The α machine 1A and the β machine 1B correspond to the hydraulic excavator 1 described above, and are given identifiable names for the purpose of explanation. In this embodiment, as shown in FIG. 2 and FIG. 3, at the work site, the α machine 1A transports soil from point A1 to point B1, and the β machine 1B transports soil from point B2 to point C1 (hereinafter referred to as A1, B1, B2, C1). The β machine 1B dumps soil onto the bed of a truck at C1. B1 and B2 are set close to each other, and as shown in FIG. 2, they form one pile of soil B. Thus, in this embodiment, the α machine 1A and the β machine 1B cooperate to transport soil from A1 onto the bed of a truck. In addition, in some of the following figures, including FIG. 2, the α machine 1A and the β machine 1B are shown in plan views, i.e., views seen from above the machine bodies, for ease of explanation. Meanwhile, the pile of soil B and the dump truck are shown in side views seen from the horizontal direction. The α machine 1A and the β machine 1B can perform the above work by rotating back and forth like windshield wipers in a plan view. Specifically, the α machine 1A and the β machine 1B rotate back and forth so as to alternately work on the pile of soil B without interfering with each other's work and movement.

[0025] Here, the α machine 1A is a remote-controlled machine operated by an operator from a remote location, and the β machine 1B is an automatically controlled machine having a cooperative nature. That is, the α machine 1A is operated by an operator from a remote location in accordance with the work plan of FIG. 3, and performs work as shown in FIG. 2 in response to this operation. The work plan includes position information of the teeth 23H of the bucket 23 that moves back and forth between A1 and B1, and the work plan may include information on the change in attitude (trajectory) of the work attachment 20 to realize the position of the teeth 23H. Furthermore, each work plan may be set in advance so that the hydraulic excavator 1 travels back and forth between two points n times (n is a natural number).

[0026] On the other hand, the β machine 1B, which is set to operate automatically, can operate according to a preset work plan, but in this embodiment, the work plan of the β machine 1B is modified as necessary to prevent interference between the α machine 1A and the β machine 1B. That is, the β machine 1B can operate in coordination with the movement of the α machine 1A. As a result, work can be performed efficiently at the work site while avoiding interference between the α machine 1A and the β machine 1B. In other words, an operator who remotely operates the α machine 1A can perform work without paying much attention to interference with the β machine 1B. In this embodiment, such coordinated operation of the β machine 1B is controlled by the control system 100.

[0027] Fig. 4 is a block diagram of the control system 100 according to this embodiment. Note that Fig. 4 also illustrates a portion of the configuration of the β machine 1B.

[0028] The hydraulic excavator 1 (α machine 1A, β machine 1B) includes an operation unit 61, a shovel control unit 62, and a drive unit 63.

[0029] The operation unit 61 includes an operation lever operated by an operator. That is, the operation unit 61 accepts operations for operating the hydraulic excavator 1. The operations include traveling of the lower traveling body 10, rotating of the upper rotating body 12, driving of the work attachment 20 (boom 21, arm 22, bucket 23), and the like. Normally, the operation unit 61 is disposed in the cab 13, but in the case of a machine operated remotely like the α machine 1A, the operation unit 61 or an operation unit having the same structure as the operation unit 61 is disposed in a remote location. In addition, in the case of an automatically controlled machine like the β machine 1B, the operation unit 61 does not function during automatic control.

[0030] The operation unit 61 also includes an input unit such as a touch panel, input buttons, and switches. The input unit accepts input of various information. As an example, the input unit accepts information for switching between automatic control, manual control, semi-automatic control (assisted control), remote control, and the like of the hydraulic excavator 1.

[0031] A display device (not shown) is disposed in the cab 13 of the hydraulic excavator 1. The display device is a liquid crystal display provided in the cab 13, and displays various information related to the operation of the hydraulic excavator 1, the progress of processing by the control system 100, and the like, and notifies the operator. At this time, the display device receives a predetermined display command signal, and displays various information to be notified to the operator in response to the display command signal. The information includes attitude information of the working attachment 20 and position information of each hydraulic excavator 1. The display device is also capable of displaying map information at the work site, and can display position information of the α machine 1A and the β machine 1B on the map. Note that the above display is an example, and may be disposed outside the cab 13, for example. That is, the display may be configured to notify the site manager of each piece of information in addition to notifying the operator of each piece of information. Note that in this embodiment, since the β machine 1B is an automatically controlled machine, there is a possibility that an operator is not on board the cab 13. For this reason, another display device similar to the above display device may be disposed in a remote location or in a management office within the work site.

[0032] During normal work, the shovel control unit 62 inputs a drive command signal to the drive unit 63 in accordance with the content of the operation received by the operation unit 61. As a result, the operations of the lower traveling body 10, the upper rotating body 12, the work attachment 20, and the like are controlled. Furthermore, when the hydraulic excavator 1 operates in the automatic operation mode, the shovel control unit 62 inputs a drive command signal to the drive unit 63 so that the teeth 23H of the bucket 23 move along a preset design surface. The drive command signal is based on a virtual trajectory along which the teeth 23H move at the work site, and the trajectory may be stored in advance in a memory unit of the α machine 1A by teaching or the like.

[0033] The driving unit 63 drives various structures of the hydraulic excavator 1 (α machine 1A, β machine 1B), and drives the lower traveling body 10, the upper rotating body 12, the work attachment 20, and the like, which are operated by the operation unit 61. In particular, the driving unit 63 can move the work attachment 20 so that the bucket 23 excavates the ground. At this time, the driving unit 63 receives a predetermined command signal (drive command signal) and drives the work attachment 20 in response to the command signal. As a result, the attitude of the work attachment 20 relative to the upper rotating body 12 can be changed. In addition, the driving unit 63 rotates the upper rotating body 12 in response to the command signal. As a result, the upper rotating body 12 can move back and forth between two points as shown in FIG. 2. The driving unit 63 includes hydraulic circuits such as a hydraulic pump, a hydraulic motor, and a control valve.

[0034] On the other hand, the control system 100 includes a control device 50, a first motion detection unit 64, and a second motion detection unit 71.

[0035] The control device 50 is installed, for example, in an administrative office adjacent to the work site. The control device 50 can perform two-way communication with each of the α machine 1A and the β machine 1B via, for example, wireless communication, and can transmit and receive command signals and the like. In another embodiment, the control device 50 may be installed in a remote location away from the work site. Also, the β machine 1B may be equipped with the control device 50.

[0036] The control device 50 is composed of a CPU (Central Processing Unit), a ROM (Read Only Memory) that stores a control program, a RAM (Random Access Memory) used as a working area for the CPU, etc. The control device 50 functions to have each of the functional parts of an operation plan acquisition part 51, an optimum calculation part 52, a rotation control part 53, and a storage part 54, by the CPU executing the control program stored in the ROM. These functional parts do not have physical entities, but correspond to units of functions executed by the control program.

[0037] It should be noted that all or a part of the control device 50 is not limited to being provided in the hydraulic excavator 1, and when the hydraulic excavator 1 is remotely controlled, the control device 50 may be provided in a location different from the hydraulic excavator 1. Furthermore, the control program may be transmitted to the control device 50 from a remote server (management device) or cloud and executed therein, or the control program may be executed on the server or cloud, and various control signals generated may be transmitted to the control device 50.

[0038] When the α machine 1A and the β machine 1B start working together, the operation plan acquisition unit 51 acquires information about the work plan that is set in advance and stored in the memory unit 54. The control device 50 may communicate with each of the α machine 1A and the β machine 1B, and the operation plan acquisition unit 51 may acquire information about the work plan stored in the memory unit of each hydraulic excavator 1. In this embodiment, the α machine 1A is a remotely controlled machine, and therefore it is sufficient for an operator staying in the remote location to know information about the work plan of the α machine 1A. Therefore, the operation plan acquisition unit 51 may acquire only the work plan of the β machine 1B, without acquiring the work plan of the α machine 1A.

[0039] The optimum calculation unit 52 generates a command signal for the β machine 1B to operate in cooperation with the α machine 1A in response to the movement of the α machine 1A so as to prevent the α machine 1A and the β machine 1B from interfering with each other in the cooperative work, or the work from interfering with each other. Here, the interference between the α machine 1A and the β machine 1B means interference (contact) between the machines, and the interference between the work means that one work machine is temporarily waiting to accomplish the work of the other work machine. In this embodiment, the optimum calculation unit 52 generates a command signal for correcting the movement of the β machine 1B based on the movement (movement speed) of the α machine 1A acquired by the first movement detection unit 64 so as to prevent the two from interfering with each other, or the work from interfering with each other, based on the movement (movement speed) of the α machine 1A acquired by the first movement detection unit 64. The swing control unit 53 inputs the command signal corrected by the optimum calculation unit 52 to the β machine 1B. As a result, the β machine 1B operates as if a part of the work plan set in advance has been changed.

[0040] The storage unit 54 stores information relating to the work plan of the hydraulic excavator 1. The information is prepared as time transitions of parameters such as acceleration, deceleration, maximum speed, acceleration start time, and deceleration start time with a predetermined work start time as a reference. Note that the method of storing information relating to the work plan is not limited to this.

[0041] The first movement detection unit 64 (first position information acquisition unit) detects information related to the movement of the α machine 1A and inputs it to the control device 50. Similarly, the second movement detection unit 71 (second position information acquisition unit) detects information related to the movement of the β machine 1B and inputs it to the control device 50. Since the first movement detection unit 64 and the second movement detection unit 71 have the same configuration, the configuration of the first movement detection unit 64 will be described below.

[0042] First, the first operation detection unit 64 detects and acquires information regarding the attitude of the work attachment 20 relative to the upper rotating body 12. As an example, the first operation detection unit 64 includes three sensors attached to the boom cylinder 21S, arm cylinder 22S, and bucket cylinder 23S, respectively, and detects the stroke (extension amount, length) of each cylinder. The stroke of each cylinder detected by each sensor is used to calculate the position and attitude of the boom 21, arm 22, and bucket 23. Note that, in order to calculate the position and attitude of the boom 21, arm 22, and bucket 23, angle sensors that detect the rotation angles of the boom 21, arm 22, and bucket 23, respectively, may be used instead of the cylinder stroke sensors.

[0043] Secondly, the first operation detection unit 64 acquires position information of the hydraulic excavator 1. As an example, the first operation detection unit 64 can acquire main body coordinate information, which is information on the absolute coordinates at the work site of a main body reference point provided in advance on the upper rotating body 12. The first operation detection unit 64 has an antenna that constitutes the main body reference point. The antenna is disposed, for example, on the upper surface of the cab 13, and functions as a GNSS mobile station. Meanwhile, a GNSS (Global Navigation Satellite System) reference station is provided (not shown) in order to acquire the main body coordinate information. The GNSS reference station is a reference station that is disposed at the work site or at a position closest to the work site. Note that, as the GNSS, in addition to the well-known GPS (Global Positioning System), satellite positioning systems such as GLONASS (Global Navigation Satellite System), Galileo, and Quasi-Zenith Satellite System (QZSS) may be adopted.

[0044] Thirdly, the first operation detection unit 64 may be capable of detecting the attitude of the hydraulic excavator 1 with respect to the ground. In this case, the first operation detection unit 64 includes an IMU (Inertial Measurement Unit) mounted on the upper rotating body 12. The IMU detects information related to the attitude of the hydraulic excavator 1 (upper rotating body 12) with respect to the ground G. In other words, the IMU detects the attitude and angle (inclination) of the hydraulic excavator 1 machine body.

[0045] The position information of the bucket 23 (first specific part) of the α machine 1A can be acquired by the above-described first operation detection unit 64. At this time, the first operation detection unit 64 can detect the position of the bucket 23 of the α machine 1A based on three-dimensional coordinates, with a predetermined specific position in the work site as the origin.

[0046] With a similar configuration, the second operation detection unit 71 can also detect the position of the bucket 23 (second specific portion) of the β machine 1B based on three-dimensional coordinates, with the specific position serving as the origin.

[0047] FIG. 5 is a schematic diagram for explaining a spring damper virtually set by the control system 100 according to the present embodiment. In FIG. 5, the α machine 1A, which is remotely controlled, and the β machine 1B, which is automatically controlled, are illustrated. The control system 100 virtually sets a spring damper between each bucket 23 so that the spring damper is displaced according to the distance between the bucket 23 of the α machine 1A and the bucket 23 of the β machine 1B. In the spring damper, the viscosity coefficient of the damper is defined as c, and the spring constant of the spring is defined as ks (both are characteristic information related to the characteristics of the spring damper). When the two buckets 23 suddenly approach each other, the virtual damper applies a brake and the elastic energy of the spring is accumulated. In other words, when the buckets 23 suddenly approach each other, the control system 100 can suppress interference between the buckets 23 by setting the viscosity coefficient c and the spring constant ks to optimal values. At this time, the control system 100 controls the operation of the β machine 1B so that the bucket 23 of the β machine 1B exhibits behavior in accordance with the above characteristic information that is set to the optimal value.

[0048] FIG. 6 is a flowchart of the entire process executed by the control system 100 according to this embodiment. For example, when an operator of the α machine 1A staying in a remote location presses a predetermined start button, the control system 100 starts the cooperative operation process of the α machine 1A and the β machine 1B. The start button is not limited to being placed in the cab 13, and may be provided on a terminal (PC, tablet, smartphone) or a remote operation device placed outside the cab 13. In this process, the operator remotely controls the α machine 1A by his / her own operation, while the β machine 1B is automatically controlled according to a work plan set in advance. Furthermore, the operation of the β machine 1B is corrected by the control system 100 as needed to avoid interference with the α machine 1A. Note that the bucket 23 of the α machine 1A is placed at A1 in FIG. 2, and the bucket 23 of the β machine 1B is placed at C1 by a worker at the work site in advance. Note that the initial position of such a bucket 23 is not limited to being placed by the worker.

[0049] When the process is started, the operation plan acquisition unit 51 of the control device 50 of the control system 100 acquires the work plan and work conditions of the β machine 1B on the automatic control side (step S1). The work conditions are information about the automatic stop position that is set in advance and stored in the storage unit 54 (automatic stop information). As an example, the automatic stop position is shown by the dashed line P in FIG. 5. The information is a position at which the swing operation of the β machine 1B is automatically stopped to prevent interference when the bucket 23 of the β machine 1B approaches the bucket 23 of the α machine 1A. Note that this position is set as a relative position to the bucket 23 of the α machine 1A. By setting the automatic stop information in advance in this way, when the bucket 23 of the α machine 1A and the bucket 23 of the β machine 1B approach each other beyond a predetermined threshold, the β machine 1B stops operating at the automatic stop position that was set in advance. Then, after the soil discharge work of the α machine 1A is completed and the α machine 1A moves away from the pile B (FIG. 2), the β machine 1B can resume work.

[0050] 6, in parallel with step S1, the operation plan acquisition unit 51 acquires turning data of the α machine 1A on the remote control side (step S2). The turning data is data related to the turning operation of the α machine 1A operated by an operator at a remote location, and includes information on the turning angle that changes from moment to moment. As described above, this information is detected by the first operation detection unit 64.

[0051] Next, the optimum calculation unit 52 (FIG. 4) of the control device 50 estimates the current rotation speed (angular velocity) of the α unit 1A from the rotation angle information acquired above (step S3). The rotation speed can be calculated by differentiating the transition of the rotation angle using a known method. Next, the optimum calculation unit 52 determines the rotation speed of the β unit 1B on the automatic control side based on the rotation speed of the α unit 1A on the remote control side (step S4). As an example, the optimum calculation unit 52 determines the rotation speed of the β unit 1B so that the rotation speed of the α unit 1A and the rotation speed of the β unit 1B are the same.

[0052] Next, the optimum calculation unit 52 determines the control parameters of the β machine 1B (step S5). The control parameters include various parameters for controlling the movement of the β machine 1B. The optimum calculation unit 52 also determines the parameters (characteristic information) of a virtual spring damper in the same manner.

[0053] Next, based on the parameters determined by the optimum calculation unit 52, the rotation control unit 53 (Figure 4) inputs a command signal to the shovel control unit 62 of the β machine 1B, thereby driving the drive unit 63 of the β machine 1B and executing the rotation operation of the β machine 1B on the automatic control side (step S6).

[0054] Next, the turning control unit 53 recognizes the current position (turning angle) of the β machine 1B based on the detection result of the second operation detection unit 71. As a result, if the work of the β machine 1B is completed according to the preset work plan (YES in step S7), the control device 50 ends the cooperative control process. On the other hand, if the work of the β machine 1B is not completed according to the preset work plan (NO in step S7), the control device 50 returns to step S2 and continues the subsequent processes.

[0055] Fig. 7 is a flowchart for further explaining the details of the calculation process executed by the control system 100 according to this embodiment. Note that the process enclosed by the dashed line in Fig. 7 is executed for each turning operation of the α machine 1A.

[0056] In Fig. 7, in process G1, the swing speed of the remote excavator, i.e., the α unit 1A, is estimated. This process corresponds to step S3 in Fig. 6, and for this purpose, in process G1, time series data (changes in swing angle) for one swing operation of the α unit 1A is input to the control device 50. When the swing speed σ of the α unit 1A is estimated through process G1, the swing speed of the β unit 1B on the automatic control side is determined accordingly (process G4, step S4). This estimated swing speed σ is also used in process G5 described later.

[0057] When the rotation speed of the β machine 1B is determined in process G4, the control parameters of the β machine 1B are determined in process G6. This process G6 corresponds to step S5 in Fig. 6. In this embodiment, the control parameters include Kp and Kd, which will be described later.

[0058] On the other hand, in process G5 of Fig. 7, the optimum calculation unit 52 of the control device 50 determines the parameters of a virtual spring damper. Prior to this, the optimum calculation unit 52 acquires information on the automatic stop position of the β machine 1B from the memory unit 54. Once the characteristic information consisting of the spring constant ks and the viscosity coefficient c is determined, the torque due to the spring damper is calculated in process G7. This torque is the torque that the spring damper including the determined characteristics provides to the upper rotating body 12 of the β machine 1B.

[0059] As shown in Fig. 7, processes G2 and G3 are performed in advance for torque calculation in process G7. In process G2, the distance between the two end attachments is calculated based on position information of the end attachment (bucket 23) of the α machine 1A acquired from the first operation detection unit 64 and position information of the bucket 23 of the β machine 1B acquired from the second operation detection unit 71. Although not shown in Fig. 7, information on the actual swing angle of the α machine 1A is also used.

[0060] Meanwhile, the position information of both end attachments is also used in process G3. Specifically, whether or not a spring damper force is generated is determined in process G3 based on the relative positional relationship between the two end attachments. Note that even if the two end attachments are far apart, there are patterns in which the spring damper force is generated. For example, in FIG. 2, when the α machine is located between A1 and B1 while rotating toward A1, if the β machine rotates from C1 toward B2, the speed is increased by the spring damper force to match the pace of the α machine. Also, whether or not the spring damper is generated is determined according to the work situation, such as when an attachment is near B2 during excavation and soil removal work at B2 or C1 and is about to stop. For this reason, if the spring damper force is not generated in the first place, information that torque calculation is unnecessary (or the torque is zero) is input to process G7.

[0061] In process G6, the control parameters of the β machine 1B on the automatic control side are determined, and in process G7, the torque by the spring damper is calculated, and based on this information, in process G8, the rotation control of the β machine 1B is executed. This process corresponds to step S6 in Fig. 6. In process G8, the control parameters Kp, Kd determined in process G6 are input, and also information corresponding to the difference between information on the work plan (target rotation angle) of the β machine 1B and information on the actual rotation angle of the β machine 1B is input.

[0062] The parameters for the turning control of the β machine 1B set in process G8 are converted into torque values, which are then added to the torque value due to the spring damper force calculated in process 7 and converted into a turning torque command value. This command value is used for the machine control (hydraulic control) of the β machine 1B in process G9, and finally, in process G10, the turning operation of the β machine 1B is executed. Information on the turning angle that changes due to the turning operation of the β machine 1B is also fed back to process G8.

[0063] FIG. 8 is a schematic diagram of the arithmetic processing executed by the control system 100 according to this embodiment. FIG. 9 is a schematic diagram of the database of the control system 100. The storage unit 54 (FIG. 4) of the control system 100 includes the databases shown in FIGS. 8 and 9. As shown in FIG. 9, the database stores a plurality of sets of data including the parameters σ, Xs, Kp, Ki, Kd, ​​ks, and c, together with assigned numbers. These pieces of information stored in the database correspond to the reference operation information (σ), reference control parameters (Kp, Ki, Kd), and reference characteristic information (ks, c) in the present invention. The method of calculating each parameter using this database will be described in detail below. Note that the following description is an example in which a PD controller is used, so in the database of FIG. 9 in this case, Ki=0 is stored.

[0064] As a first process, the optimum calculation unit 52 of the control device 50 acquires data on the rotation speed σ(t) of the α machine 1A and the automatic stop position Xs(t) of the β machine 1B. Both of these are functions with time t as a variable.

[0065] As a second process, the optimum calculation unit 52 calculates nearby data sets. Here, if the distances of the respective data sets are d1, d2, d3, ..., then di is defined by the following formula 1. Then, the optimum calculation unit 52 selects n nearby data sets from the database in ascending order of di based on formula 1.

[0066]

number

[0067] As a third process, the optimum calculation unit 52 performs a weighting process according to the distance di. In this case, the weight wi is set as shown in the following formula 2.

[0068]

number

[0069] As the fourth process, the optimum calculation unit 52 calculates each parameter based on the known local linear averaging method. As an example, for Kp, if the number of neighboring data sets is n=3, the latest Kp, Kp_new, is calculated by the following formula 3.

[0070]

number

[0071] Although the above describes Kp, the latest values ​​of the other parameters are calculated in the same manner.

[0072] As a fifth process, the optimum calculation unit 52 stores the new data set calculated above in the database, and deletes redundant data. The new data set is composed of [σ(t), Xs(t), Kp_new, Ki_new, Kd_new, ks_new, c_new]. Here, the deletion of redundant data sets needs to be executed only when a data set very similar to the new data set already exists.

[0073] Here, the calculation of each parameter by the optimum calculation unit 52 can employ either a method using a database as described above or a method not using a database.

[0074] FIG. 10 is a flowchart showing how the control system 100 according to this embodiment calculates characteristic information and control parameters. The flowchart in FIG. 10 is a simplified version of the flowcharts in FIG. 6 and FIG. 7 in order to explain the flow of calculation for each parameter. This flowchart corresponds to the dashed line portion in FIG. 7, and processing is executed at a different timing from other portions. For example, the control of other portions is executed every 0.1 sec, while the control of the dashed line portion in FIG. 7 is executed every time the first operation detection unit 64 detects the end of one rotation operation of the α machine 1A. As shown in FIG. 10, when the rotation data of the remotely controlled α machine 1A is acquired in step S11, the rotation speed of the α machine 1A is estimated in step S12. Furthermore, the control parameters Kp and Kd of the β machine 1B are calculated in step S13, and the rotation control of the β machine 1B is executed in step S14.

[0075] On the other hand, when information on the automatic stop position of the β machine 1B is acquired in step S21, the spring constant ks and viscosity coefficient c of the spring damper are calculated in step S22, and the torque by the spring damper is calculated in step S23.

[0076] Here, as explained above, a calculation method using a database can be adopted in steps S13 and S22.

[0077] Next, a description will be given of a mode in which the control parameters of the β machine 1B are calculated based on the automatic stop position and remote swing speed σ of the β machine 1B, and the characteristic information of the spring damper is determined using a database. FIG. 11 is a schematic diagram illustrating the swing operation of the hydraulic excavator 1 according to this embodiment. FIG. 12 is a flowchart showing how a control system 100 according to another embodiment of the present invention calculates characteristic information and control parameters. This other embodiment differs from the previous embodiment in that a database is used to calculate the characteristic information (ks, c) of the spring damper, but a predetermined calculation formula is used to calculate the control parameters (Kp, Kd) of the β machine 1B without using a database.

[0078] 12, when the turning data of the remotely controlled α machine 1A is acquired in step S31, the turning speed of the α machine 1A is estimated in step S32. Furthermore, the control parameters Kp, Kd of the β machine 1B are calculated in step S33, and the turning control of the β machine 1B is executed in step S34.

[0079] On the other hand, when information on the automatic stop position of the β machine 1B is acquired in step S41, the spring constant ks and viscosity coefficient c of the spring damper are calculated from the database in step S42 using the rotation speed σ of the α machine 1A acquired in the previous step S32, and the torque due to the spring damper is calculated in step S43.

[0080] Here, the calculation method of the control parameters in step S33 will be described in more detail. Referring to Fig. 11, when the movements of the α machine 1A and the β machine 1B are regarded as an equation of motion of a rotating rod, the movements can be expressed as in the following formula 4.

[0081]

number

[0082] where I is the moment of inertia (kg m 2 ), ω is the angular velocity (rad / sec), τ is the torque (N·m), D is the viscosity coefficient (Pa·sec) in the movement (hydraulic pressure, friction, etc.) of the working attachment 20 of the hydraulic excavator 1, and θ is the arm angle (rad). Note that a dot above the symbol in equation 4 indicates a differential. Here, M is the weight of the hydraulic excavator 1 (kg), and L is the arm length (m).

[0083] When Equation 4 is Laplace transformed using a known method, it can be expressed as Equation 5 below.

[0084]

number

[0085] As is well known, s means a variable after Laplace transformation. Equation 5 includes elements of a first-order lag and an integral system, and its solution can be obtained by considering it as a well-known PD controller. Therefore, consider the closed loop transfer function shown in Equation 6.

[0086]

number

[0087] To solve the transfer function of Equation 6, a reference trajectory is defined as shown in Equation 7 below.

[0088]

number

[0089] Here, α2 = M2 × L2 2 If β2 = 3 × D2 and K2 = 3, the control parameters (gain K p , K d ) are shown respectively.

[0090]

number

[0091]

number

[0092] The spring constant ks and viscosity coefficient c may be calculated using the following method. Specifically, if the automatic operation stop position of the β machine 1B is set at a position where the rotation angle is 120 degrees, the spring constant is determined so that the input of the controller and the torque due to the spring are balanced at this 120 degree position. The relationship between the input of the controller and the torque due to the spring is shown in the following formula 10.

[0093]

number

[0094] Dis_att at the end of formula 10 corresponds to the distance between the buckets 23 (tip attachments) of the α machine 1A and the β machine 1B. Therefore, by solving the equation at the end of formula 10, the spring constant ks can be determined.

[0095] On the other hand, regarding the viscosity coefficient c, let us consider converging to the target turning angle without overshooting during the turning operation of the β machine 1B at maximum acceleration. Here, in the work conditions shown in FIG. 2, maximum acceleration means a state in which the α machine 1A is located at 180 degrees, i.e., at point A, and the β machine 1B is located at 0 degrees, i.e., at point C, and the β machine 1B starts turning toward point B2. In this case, an optimal c is selected in advance by trial and error through simulation calculation. Then, only the viscosity coefficient c may be calculated from the database in the same manner as the first to fifth processes described using FIG. 9.

[0096] Next, a description will be given of a pattern for controlling the swing operation of the β machine 1B obtained by the calculation method in each of the above embodiments. Figures 13, 14, and 15 are schematic diagrams for explaining the movement of the hydraulic excavator 1 controlled by the control system 100 according to one embodiment of the present invention.

[0097] In the example of Fig. 13, the α machine 1A controlled remotely is turning from point B1 to the A1 side, while the β machine 1B controlled by the automatic controller is turning toward point B2 with a delay as shown by arrow D1. In this case, a torque that speeds up the turning motion of the β machine 1B is generated by the virtual spring damper. As a result, the turning motion of the β machine 1B is accelerated, and the work of the β machine 1B can be performed efficiently while preventing interference between the α machine 1A and the β machine 1B.

[0098] In the example of Fig. 14, this corresponds to a case where the α machine 1A controlled remotely is turning from point A1 to B1, while the β machine 1B controlled by the automatic controller is turning toward point B2 with a delay as shown by arrow D2. In this case, a torque that slows down the turning speed of the β machine 1B is generated by a virtual spring damper. As a result, the turning motion of the β machine 1B is decelerated, and the α machine 1A can turn from point B1 to A1, while preventing interference between the α machine 1A and the β machine 1B, and then the β machine 1B can reach point B2.

[0099] The example in FIG. 15 corresponds to a case where the α machine 1A, which is remotely controlled, is located at point B1 and has not yet started to turn to point A1, while the β machine 1B is approaching point B2. In other words, it corresponds to a case where the β machine 1B is turning toward an area where there is a possibility of a collision between the two. In this case, a torque that slows down the turning speed of the β machine 1B is generated by the virtual spring damper as shown by arrow D3. In addition, the control parameters and spring damper characteristic information of the β machine 1B are set so that the torque command value generated by the controller and the torque generated by the spring damper are balanced at the automatic stop position P preset for the β machine 1B.

[0100] As described above, in the control system 100 according to each embodiment of the present invention, the control device 50 generates a command signal for the β machine 1B, which is automatically controlled according to the movement of the remotely controlled α machine 1A, to operate in coordination with the α machine 1A so as to prevent interference between the α machine 1A and the β machine 1B, or interference between the operations of the α machine 1A and the β machine 1B. More specifically, the control device 50 determines characteristic information ks and c related to the characteristics of a spring damper virtually set between the buckets 23 of the α machine 1A and the bucket 23 of the β machine 1B so as to displace according to the distance between the two buckets, and control parameters Kp and Kd for controlling the β machine 1B, based on operation information related to the movement of the α machine 1A, and generates the command signal (drive command signal) for the β machine 1B based on the determined characteristic information and control parameters.

[0101] According to this configuration, by optimizing the operation of the cooperative β machine 1B, it is possible to perform efficient work while preventing the machines from coming into contact with each other. Note that in this manner, the operation mode of the α machine 1A and the β machine 1B in which the β machine 1B operates cooperatively in accordance with the movement of the α machine 1A may be any of the automatic mode, manual mode, and semi-automatic mode. In the manual mode and semi-automatic mode, a command signal (assist signal) output by the control system is input to the shovel control unit 62 of the hydraulic excavator 1, making it possible to assist the operation of the operator. Also, the work machine represented by the hydraulic excavator 1 may be another machine such as a bulldozer.

[0102] In the above configuration, the control device 50 may determine the characteristic information and the control parameters based on the operation information and automatic stop information for stopping the movement of the β machine 1B that is set in advance.

[0103] According to this configuration, the characteristic information and control parameters are determined taking into consideration the stopping information for stopping the movement of the β machine 1B in advance, so that interference between the α machine 1A and the β machine 1B can be prevented with high accuracy.

[0104] In this embodiment, the control device 50 further includes a database that stores in advance reference motion information corresponding to the motion of the α machine 1A, reference characteristic information corresponding to the characteristic information, and reference control parameters corresponding to the control parameters in association with each other. The control device 50 inputs input information, which is the current motion information of the α machine 1A, into the database, identifies the reference motion information corresponding to the input information, and generates the command signal using the reference characteristic information and the reference control parameters corresponding to the identified reference motion information. Note that various types of reference information are information that are previously obtained by experiments or the like and stored in the database. Meanwhile, the input information is current motion information detected by the first motion detection unit 64 or the like. The reference motion information is data that is optimal (closest) to the input information among the information stored in the database, and the reference characteristic information and the reference control parameters are information included in one data set associated with the reference motion information.

[0105] According to this configuration, by extracting optimal control parameters and characteristic information from a plurality of data sets stored in the database, interference between the α machine 1A and the β machine 1B can be prevented with high accuracy.

[0106] In the above configuration, the α machine 1A may be operated by an operator on board or by remote control, and the β machine 1B may be operated by automatic control.

[0107] According to this configuration, even when an operator operates the α machine 1A by boarding the α machine 1A or when the operator operates the α machine 1A from a remote location, there is no need to pay much attention to the movement of the β machine 1B, and the operations of both machines can be efficiently performed while preventing interference between the α machine 1A and the β machine 1B. In particular, when the α machine 1A is remotely controlled, the database also stores the operator's characteristics together with control parameters, etc., so that the β machine 1B can be coordinated to match the skill and operation characteristics of the current remote control operator. This allows the β machine 1B to operate in accordance with the skill, operation characteristics, and work pace of the remote control operator, improving the comfort of the operator during work. For example, the operator can work at his or her own pace and does not have to worry about the β machine 1B.

[0108] The control system 100 according to the embodiment described above can include the following characteristic technical ideas. That is, the operation speed of the remote α machine 1A is estimated using operation information of the remote α machine 1A acquired in real time. Furthermore, the operation speed of the automatic β machine 1B is updated in accordance with the operation speed of the remote α machine 1A. Then, it is assumed that a virtual spring damper force is generated between the remote α machine 1A and the automatic β machine 1B, and the operation speed of the automatic β machine 1B is adjusted by this force. As a result, it is possible to realize a coordinated operation of the automatic β machine 1B in accordance with the movement of the remote α machine 1A.

[0109] In this way, by realizing the coordinated operation of the automated β machine 1B in accordance with the operation of the remote α machine 1A, it is possible to improve the work productivity of a work site having multiple work machines. Also, the automated side can perform operations in accordance with the work speed and operation skills of the remote operator. Furthermore, the remote operator operating the α machine 1A can comfortably and safely concentrate on his or her own work without having to be aware of the operation of the automatic control β machine 1B. Also, the automatic control β machine 1B can efficiently perform work at a speed that matches the remote operator.

[0110] In addition, in this embodiment, since the database can store various information, it is possible to store in advance the motion speed and working conditions of the remote operator (such as the stopping position for the automatic β machine 1B to avoid contact for safety reasons), as well as the control parameters and virtual spring damper parameters of the automatic β machine 1B that can realize efficient cooperative work under those conditions. In addition, the estimated motion speed of the remote α machine 1A and working conditions such as the specified stopping position can be input, and the control parameters and the like of the automatic β machine 1B can be appropriately adjusted using the database. At this time, data obtained in the past can be effectively utilized based on the update of the database.

[0111] In the above description, the remotely controlled α machine 1A and the automatically controlled β machine 1B are used, but the α machine 1A may be operated by an operator actually riding in the cab 13 instead of being remotely controlled, or may be automatically controlled like the β machine 1B. In this case, since both the α machine 1A and the β machine 1B are automatically controlled, it is desirable to set in advance which hydraulic excavator 1 should have priority for its work.

[0112] Although one embodiment of the work machine control system 100 according to the present invention has been described above, the present invention is not limited to the above embodiment.

[0113] In the above embodiment, the control system 100 has been described as being mounted on part of a work site or on the hydraulic excavator 1, but part of the control system 100 may be disposed at a location remote from the hydraulic excavator 1. In this case, the structure of the control system 100 mounted on the hydraulic excavator 1 and the structure disposed at a location remote from the hydraulic excavator 1 may transmit and receive information via wireless communication or the like.

[0114] In the above embodiment, the bucket 23 has been described as the specific part of each hydraulic excavator 1, but the specific part may be a part of the work attachment 20 other than the bucket 23. Also, a part of the hydraulic excavator 1 other than the work attachment 20 may be the specific part. [Explanation of symbols]

[0115] 1. Hydraulic excavator (working machine) 10 Undercarriage 100 Control System 12 Upper rotating body 13 Cab 1A α machine (1st working machine) 1B β machine (2nd working machine) 20 Work attachment 21 Boom 22 Arm 23 Bucket 50 Control device (control unit) 51 Motion plan acquisition unit 52 Optimal Calculation Unit 53 Rotation control section 54 Storage section 61 Operation section 62 Excavator control unit 63 Drive unit 64 First motion detection unit (first position information acquisition unit) 71 second motion detection unit (second position information acquisition unit)

Claims

1. A work machine control system that controls an operation of at least a second work machine at a work site where a first work machine and a second work machine work, comprising: a control unit that generates a command signal for causing the second work machine to operate in cooperation with the first work machine in response to movement of the first work machine so as to prevent at least one of interference between the first work machine and the second work machine and interference between the tasks of the first work machine and the second work machine, The control unit determines, based on operation information relating to at least the movement of the first work machine, characteristic information relating to characteristics of a spring damper that is virtually set between a first specific portion of the first work machine and a second specific portion of the second work machine so as to displace in accordance with the distance between the first specific portion and the second specific portion of the second work machine, and control parameters for controlling the second work machine, and generates the command signal based on the determined characteristic information and control parameters.

2. 2. The work machine control system according to claim 1, wherein the control unit determines the characteristic information and the control parameters based on the operation information and preset automatic stop information for stopping the movement of the second work machine.

3. a database that pre-stores reference operation information corresponding to a movement of the first working machine, reference characteristic information corresponding to the characteristic information, and reference control parameters corresponding to the control parameters in association with each other; 3. The work machine control system according to claim 1 or 2, wherein the control unit inputs input information that is the current operation information of the first work machine into the database, identifies the reference operation information that corresponds to the input information, and generates the command signal using the reference characteristic information and the reference control parameter that correspond to the identified reference operation information.

4. 3. A work machine control system according to claim 1 or 2, wherein the first work machine is operated by an operator on board or is operated by remote control, and the second work machine is operated by automatic control.

Images