Work machine, and remote control device

Abstract

To suppress deviations in recognition of an actual positional relationship with a transport vehicle, and to accurately load soil and sand onto a transport vehicle with high precision while moving a bucket on a locus with minimal loss.SOLUTION: A work machine comprises: an object detection device detecting surrounding objects; a travel sensor detecting operation of a travel body; a displacement sensor detecting displacement of the travel body; a drive device driving the travel body, a swing body, and a front work device; and a control device controlling the drive device on the basis of detection results of the object detection device, the travel sensor, and the displacement sensor. The control device: calculates, on the basis of a detection signal of the object detection device, a position of an object serving as a reference for control of the travel body, the swing body, and the front work device; controls the swing body and the front work device on the basis of the position of the object; and re-calculates, on the basis of detection signals of the travel sensor and the displacement sensor, the position of the object when the travel body is displaced while operation of the travel body is stopped.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a work machine such as a hydraulic excavator and a remote control device. [Background technology]

[0002] 2. Description of the Related Art In recent years, in working machines such as hydraulic excavators and bulldozers, automation and semi-automation of work has been progressing, for example, in which a control system intervenes in controlling the working machine in response to specific operations by an operator.

[0003] As an example of automatic control of a hydraulic excavator, a technology has been disclosed in which after the bucket is moved towards a target position, the destination area is recognized by a sensor, and the bucket position is corrected if the bucket position deviates from the actual target position recognized by the sensor (Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2022-77328 Summary of the Invention [Problem to be solved by the invention]

[0005] Hydraulic excavators are sometimes used as loading machines that load excavated soil and sand onto a dump truck, which is a transport vehicle. When automating or semi-automating the loading of soil and sand onto a transport vehicle, the control system is required to have high accuracy in identifying the relative position of the transport vehicle with respect to the hydraulic excavator. However, the hydraulic excavator may have its tracks slip on the ground due to a reaction force when excavating the ground, and the vehicle body may be pulled to the excavation position. In this case, the hydraulic excavator moves relative to the transport vehicle, but since this movement is not instructed by the operator or the control system, the actual relative positions of the hydraulic excavator and the transport vehicle are shifted from the relative positions recognized by the control system. When automatic loading control is executed in this state, the position where the soil is loaded by the hydraulic excavator is shifted, causing soil to spill from the transport vehicle, etc., resulting in reduced productivity.

[0006] In contrast, in the case of the technology described in Patent Document 1, after the bucket is moved toward the target position, a sensor recognizes the actual target position and corrects the bucket position as necessary. Therefore, even if the relative positions of the hydraulic excavator and the transport vehicle are shifted, the bucket position is corrected before releasing the soil, and the deviation in the loading position can be corrected.

[0007] However, in the technology of this document, the bucket is moved toward the target position, and then the bucket position is checked and corrected, so the bucket does not necessarily move to the loading position along the shortest trajectory, which can result in lost time in bucket movement, and productivity decreases if such an operation is repeated.

[0008] An object of the present invention is to provide a work machine and a remote control device that can suppress discrepancies in the recognition of the actual positional relationship with a transport vehicle, and accurately load soil and sand onto a transport vehicle while moving a bucket on a trajectory with minimal loss. [Means for solving the problem]

[0009] In order to achieve the above object, the present invention provides a work machine including a running body, a rotating body rotatably provided on the upper part of the running body, and a front work machine attached to the rotating body, the work machine comprising: an object detection device that detects objects around the work machine, a running sensor that detects the movement of the running body, a displacement sensor that detects the displacement of the running body, a drive unit that drives the running body, the rotating body, and the front work machine, and a control device that controls the drive unit based on detection results of the object detection device, the running sensor, and the displacement sensor, the control device calculates the position of an object that serves as a reference for control of the running body, the rotating body, and the front work machine based on a detection signal from the object detection device, controls the rotating body and the front work machine based on the position of the object, and recalculates the position of the object based on the detection signals from the running sensor and the displacement sensor if the running body is displaced while the operation of the running body is stopped. Effect of the Invention

[0010] According to the present invention, it is possible to suppress deviations in recognition of the actual positional relationship with the transport vehicle, and to load soil and sand onto the transport vehicle with high accuracy while moving the bucket on a trajectory with minimal loss. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a side view of a hydraulic excavator, which is an example of a work machine according to a first embodiment of the present invention. [Diagram 2] FIG. 2 shows an example of a work site of the work machine of FIG. 1. [Diagram 3] A functional block diagram of a control device provided in the work machine of FIG. [Figure 4] 1 is a flowchart showing an example of a processing procedure performed by a control device provided in a work machine according to a first embodiment of the present invention. [Diagram 5] A diagram showing how unintended movement of a hydraulic excavator can occur [Figure 6] 10 is a flowchart showing an example of a processing procedure performed by a control device provided in a work machine according to a second embodiment of the present invention. [Figure 7] 10 is a flowchart showing an example of a processing procedure performed by a control device provided in a work machine according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0013] In this embodiment, a large hydraulic excavator capable of automatic operation will be described as an example of a work machine that is an automatic loading machine. However, the present invention is not limited to large hydraulic excavators, and can also be applied to work machines that are the subject of automatic operation in cooperation with other vehicles, such as small hydraulic excavators and large crane vehicles. Furthermore, the present invention is not limited to automatic operation, and can also be applied to operation assist control that semi-automatically assists the operation of an operator and operation assist control for remote operation.

[0014] (First embodiment) <Work machinery> 1 is a side view of a hydraulic excavator 1, which is an example of a work machine according to a first embodiment of the present invention. The hydraulic excavator 1 includes a traveling body 5, a rotating body 3, a front work unit 4, drive units 7a and 7b, an object detection device 8, and a control device 6.

[0015] -Traveling vehicle- The traveling body 5 has a traveling motor, and travels when the traveling motor is driven by the drive device 7b, moving the hydraulic excavator 1 forward, backward, left and right, and turning (pivoting) on ​​the spot. The traveling body 5 is of a crawler type, but can also be of a wheel type.

[0016] -Rotating body- The rotating body 3 is rotatably provided on the upper part of the running body 5, and a rotary motor is driven by a drive unit 7a to rotate left and right relative to the running body 5. The rotating body 3 also includes a driver's cab 2 for an operator to operate the hydraulic excavator 1, drive units 7a and 7b, a control device 6, etc.

[0017] -Front work equipment- The front working mechanism 4 is attached to the rotating body 3 and includes, for example, a boom 4a, an arm 4b, and a bucket 4c. The boom 4a is driven by a boom cylinder 4d, the arm 4b by an arm cylinder 4e, and the bucket 4c by a bucket cylinder 4f. The boom cylinder 4d, the arm cylinder 4e, and the bucket cylinder 4f are driven by a drive device 7a.

[0018] -Drive unit- The drive unit 7 includes a drive unit 7a that drives the front working mechanism 4 and the rotating body 3, and a drive unit 7b that drives the traveling body 5. The drive unit 7 is made up of various hydraulic devices such as a hydraulic pump and a control valve. An engine (internal combustion engine) can be used as the prime mover that drives the hydraulic pump, and an electric motor may be used instead of the engine.

[0019] -Object detection device- The object detection device 8 is a sensor that detects objects (including the terrain and the ground surface) around the hydraulic excavator 1, and is connected to the control device 6 via a signal line. In this embodiment, the object detection device 8 detects the relative position of an object around the hydraulic excavator 1 with respect to the object detection device 8 and the distance from the object detection device 8 to the object, and outputs the detection result. The object detection device 8 acquires data corresponding to the distance from the object detection device 8 to the target object around the hydraulic excavator 1, and this data is input to the control device 6 as an output signal from the object detection device 8. For the object detection device 8, for example, a stereo camera, a LiDAR (Light Detection And Ranging) device, or the like can be used. It is also possible to provide a plurality of object detection devices 8 or combine a plurality of types of devices with different methods to expand the measurement area and improve the measurement accuracy.

[0020] -Sensor- The hydraulic excavator 1 shown in Fig. 1 includes a motion detection sensor 10a (Fig. 3) provided on the drive unit 7a, a travel sensor 10b (Fig. 3) provided on the drive unit 7a, and a displacement sensor (described later) that detects the displacement of the travelling body 5. The motion detection sensor 10a includes a sensor that detects the motion of the front working implement 4 and a sensor that detects the motion of the revolving body 3. Each of these sensors is connected to the control device 6 via a signal line.

[0021] -Sensor that detects the operation of the front work equipment As a sensor for detecting the operation of the front work implement 4, for example, a pressure sensor for detecting the pressure of the bottom side oil chamber and the rod side oil chamber of the boom cylinder 4d, the arm cylinder 4e, and the bucket cylinder 4f, respectively, can be used. In addition, an angle sensor for detecting the angles of the boom 4a, the arm 4b, and the bucket 4c can also be used as a sensor for detecting the operation of the front work implement 4. An IMU (Inertial Measurement Unit) for detecting the acceleration, angular velocity, angle, etc. of the boom 4a, the arm 4b, and the bucket 4c, and a sensor for detecting each operation signal related to the boom 4a, the arm 4b, and the bucket 4c can also be used as a sensor for detecting the operation of the front work implement 4. Furthermore, when an electric motor or the like is used for the drive device 7a, an ammeter or a voltmeter can also be used as a sensor for detecting the operation of the front work implement 4.

[0022] Sensor that detects the movement of the rotating body As a sensor for detecting the operation of the rotating body 3, for example, a pressure sensor for detecting the port pressure of the rotating motor can be used. In addition, an angle sensor for detecting the angle of the rotating body 3 relative to the running body 5 can also be used as a sensor for detecting the operation of the rotating body 3. An IMU for detecting the acceleration, angular velocity, angle, etc. of the rotating body 3, or a sensor for detecting an operation signal related to the rotating body 3 can also be used as a sensor for detecting the operation of the rotating body 3. Furthermore, when an electric motor or the like is used for the driving device 7a, an ammeter or a voltmeter can also be used as a sensor for detecting the operation of the rotating body 3.

[0023] Sensors that detect the movement of moving objects The travel sensor 10b is a sensor that detects the operation of the running body 5, and may be, for example, a pressure sensor that detects each port pressure of the left and right running motors. In addition, an IMU that detects the acceleration, angular velocity, angle, etc. of the running body 5, or a sensor that detects an operation signal related to the running body 5 may be used as a sensor that detects the operation of the running body 5. Furthermore, when an electric motor or the like is used for the drive device 7b, an ammeter or a voltmeter may be used as a sensor that detects the operation of the running body 5.

[0024] Sensor that detects the displacement of the moving object In addition, as a displacement sensor that detects the displacement of the running body 5, a positioning device (position and orientation measuring instrument) 9 that acquires the position of the rotating body 3 and the object detection device 8 mentioned above are installed, and at least one of the positioning device 9 and the object detection device 8 can be used as a displacement sensor to detect basic data for calculating the amount of change in the position and orientation of the running body 5.

[0025] The positioning device 9 is a sensor that can acquire the position and azimuth angle based on an arbitrary point at the site of the hydraulic excavator 1. For example, a Global Navigation Satellite System (GNSS) or a GNSS compass that calculates the direction from the difference in the positions of GNSS mobile stations installed at intervals on the rotating body 3 can be used as the positioning device 9. The position and direction of the rotating body 3 can be converted to the position and direction of the running body 5 based on data such as the angle of the rotating body 3 relative to the running body 5, dimensional data of the rotating body 3 and the running body 5, and the positions of the GNSS mobile stations relative to the rotating body 3.

[0026] <Control device> The control device 6 is an on-board computer that controls the drive device 7 based on the detection results of the object detection device 8, the travel sensor 10b, the positioning device 9, the motion detection sensor 10a, etc., and controls the running body 5, the revolving body 3, and the front work unit 4, and is, for example, a programmable electronic device equipped with a CPU and a memory. As described above, the control device 6 is connected to sensors such as the object detection device 8, the positioning device 9, the motion detection sensor 10a, and the travel sensor 10b via signal lines, and is also connected to the operation device of the cab 2 and each of the control target devices included in the drive devices 7a and 7b via signal lines. For example, the control device 6 issues commands to the drive devices 7a and 7b in response to operation signals input from an operation device (not shown) in accordance with the operation of an operator in the cab 2, and drives the front work unit 4, the revolving body 3, and the running body 5. In addition, the control device 6 has the function of generating command signals for automatically or semi-automatically controlling the front working mechanism 4, the rotating body 3, and the running body 5 according to an automatic driving program or semi-automatically driving program without the operation of an operator, and outputting the command signals to the drive devices 7a, 7b.

[0027] - Overview of control device processing - Fig. 2 is a diagram showing an example of an operating site of the hydraulic excavator 1. In the example shown in Fig. 2, the hydraulic excavator 1 is performing an excavation and loading operation in which the hydraulic excavator 1 excavates the ground, scoops up soil and sand into a bucket 4c, and loads the soil and sand into a tray of a dump truck 11 (transport vehicle) by a combined operation of the front working implement 4 and the swing mechanism 3.

[0028] The main functions of the control device 6 will be briefly described below. First, the control device 6 calculates the position of an object that is the reference for controlling the traveling body 5, the revolving body 3, and the front working machine 4 based on the detection signal of the object detection device 8, controls the revolving body 3 and the front working machine 4 based on the position of the object, and recalculates the position of the object based on the detection signals of the travel sensor 10b and the displacement sensor (the positioning device 9 or the object detection device 8) if the traveling body 5 is displaced while the operation of the traveling body 5 is stopped. Specifically, the control device 6 calculates the position of the object (for example, a specific area 12 on the ground to be leveled, or a tray area 14a of a dump truck 11 for loading soil and sand) in a three-dimensional reference coordinate system 13 whose positional relationship with the traveling body 5 is invariable based on the detection signal of the object detection device 8, and stores the calculated position of the object in a memory. The control device 6 calculates the attitude and trajectory of the bucket 4c based on the position of the held object, and executes automatic control or semi-automatic assist control of the revolving body 3 and the front work unit 4 so that the bucket 4c moves along the calculated trajectory with the calculated attitude. While repeating such excavation and loading operations, the control device 6 judges whether the traveling body 5 has stopped based on the detection signal of the travel sensor 10b, and judges whether the traveling body 5 has been displaced to a preset threshold value or more based on the detection signal of the displacement sensor (positioning device 9 or object detection device 8). At that time, the displacement amount of the traveling body 5 is calculated by the control device 6 based on at least one of the detection signals of the positioning device 9 and the object detection device 8. In other words, the control device 6 judges whether the traveling body 5 has moved or turned even though the operator or the control device 6 has not instructed the operation of the traveling body 5.

[0029] When the running body 5 starts to operate, or when the running body 5 is displaced by a preset threshold value or more while the running body 5 is stopped, the control device 6 recalculates the position of the object, deletes the currently held data on the position of the object, and updates the position of the object to the recalculated data. Thereafter, the control device 6 controls the rotating body 3 and the front working implement 4 based on the updated position of the object in the same manner as before the update.

[0030] Conversely, when the traveling body 5 is stopped and the displacement of the traveling body 5 during that time is less than the threshold value, the control device 6 determines that the currently held position of the object is still valid and continues to hold the position of the object currently held in the memory as valid data. In this case, the control device 6 does not perform recalculation processing of the object position, but controls the rotating body 3 and the front working implement 4 based on the continuously held position of the object.

[0031] -Control device function block- Figure 3 is a functional block diagram of the control device 6 provided in the work machine of Figure 1. Control of the front work implement 4 and the like and processing for updating objects are realized by the various functions illustrated in the functional block diagram of Figure 3.

[0032] 3, the control device 6 includes a control target value acquisition unit 6a, a control target value storage unit 6b, a control output unit 6c, a relative information change detection unit 6d, and a control target value update instruction unit 6e. The control target value acquisition unit 6a, the control target value storage unit 6b, the control output unit 6c, the relative information change detection unit 6d, and the control target value update instruction unit 6e are, for example, functions of the control device 6, and may be virtually realized by software or may be realized by hardware such as an electronic circuit.

[0033] -Control target value acquisition section- The control target value acquisition unit 6a receives distance data (output signal of the object detection device 8) from the object detection device 8, and calculates the relative distance of the object from the hydraulic excavator 1 based on the distance data. The object is, for example, a dump truck 11 (FIG. 1) to which the hydraulic excavator 1 loads soil and sand, or a specific area 12 (FIG. 1) of the ground that the hydraulic excavator 1 levels. For example, when the dump truck 11 is the object, the control target value acquisition unit 6a identifies the dump truck 11 based on distance data around the hydraulic excavator 1, and calculates the relative distance from the hydraulic excavator 1 to the tray of the dump truck 11. The relative distance is expressed, for example, as a three-dimensional vector 14b indicating the position on the reference coordinate system 13 (FIG. 2) of a center point 14c of a tray area 14a of the dump truck 11, which is the target discharge position of soil and sand. The control target value acquisition unit 6a transmits the calculated data of the relative distance to the object to the control target value storage unit 6b as data of the position of the object.

[0034] -Control target value storage section- The control target value storage unit 6b has a memory, and when it receives the relative distance data to the target object from the control target value acquisition unit 6a, it stores the relative distance data in the memory. When it receives the relative distance data from the control target value acquisition unit 6a, it discards the currently stored relative distance data, stores the newly received relative distance data from the control target value acquisition unit 6a in the memory, and updates the relative distance data. Also, when it receives an update instruction from the control target value update instruction unit 6e as described below, the control target value storage unit 6b transmits an instruction to the control target value acquisition unit 6a to newly calculate and output the relative distance data, and replaces the newly input relative distance data from the control target value acquisition unit 6a with the currently stored relative distance data to update it. The control target value storage unit 6b outputs the stored relative distance data to the control output unit 6c.

[0035] -Control output section- The control output unit 6c calculates control signals for driving and controlling the revolving body 3, the front work unit 4, and the traveling body 5, and outputs control signals to the drive unit 7 (drive units 7a, 7b). As an example of drive control, when the object is a dump truck 11, the control output unit 6c calculates the attitude and shortest trajectory of the bucket 4c required for loading into the dump truck 11 based on the relative distance data received from the control target value holding unit 6b, calculates control signals for the front work unit 4 and the revolving body 3 so that the bucket 4c moves at the calculated attitude and trajectory, and outputs the control signals to the drive unit 7a. When the object is an area 12 on the ground shown in FIG. 2, the control output unit 6c calculates the attitude and trajectory of the front work unit 4 for leveling the ground, calculates a control signal for the front work unit 4 so that the bucket 4c moves at the calculated attitude and trajectory, and outputs the control signal to the drive unit 7a.

[0036] - Relative information change detection section - The relative information change detection unit 6d detects unintended movement (change in the position of the traveling body 5) or turning (change in the direction of the traveling body 5) of the hydraulic excavator 1 based on the output signal of the positioning device 9 or the object detection device 8. Unintended movement or turning refers to, for example, movement or turning of the traveling body 5 occurring even though the control output unit 6c has not commanded the drive unit 7b to drive the traveling body 5. When the relative information change detection unit 6d detects movement or turning of the traveling body 5 as described below while detecting the stationary state of the traveling body 5 based on the output signal of the travel sensor 10b (for example, in a state where no drive command is output from the control output unit 6c to the traveling body 5 or the travel motor is stopped), the relative information change detection unit 6d outputs the amount of movement or turning as a displacement amount to the control target value update instruction unit 6e.

[0037] For example, the relative information change detection unit 6d can calculate the amount of movement and turning angle of the running body 5 based on the amount of movement and rotation of the reference coordinate system 13 of the hydraulic excavator 1 in the on-site coordinate system 15 (a coordinate system based on the ground and including the global coordinate system), which is the coordinate system of the operating site of the hydraulic excavator 1, based on the output of the positioning device 9.

[0038] Furthermore, the relative information change detection unit 6d may be configured to calculate the amount of movement and the amount of turning of the vehicle 5 based on a change in the value of the vector 14b calculated based on the output of the object detection device 8. Compared to processing a three-dimensional image of an object using the object detection device 8, the displacement determination process using the object detection device 8 has a small calculation load and can be executed frequently and reasonably. For example, by using SLAM (Simultaneously Localization and Mapping) technology, it is possible to identify the position and direction of the vehicle 5 while identifying the position of the dump truck 11 based on the relative distance data from the object detection device 8.

[0039] -Control target value update instruction section- When the control target value update instruction unit 6e receives the amount of displacement from the relative information change detection unit 6d, the control target value update instruction unit 6e determines whether or not the relative distance data held by the control target value holding unit 6b needs to be updated based on the received amount of displacement, and outputs an update instruction to the control target value holding unit 6b if it determines that an update is necessary. For example, when the following condition is satisfied, the control target value update instruction unit 6e determines that the relative distance data held by the control target value holding unit 6b needs to be updated. Displacement ≧ Threshold value...(Equation 1)

[0040] The threshold value used for the movement judgment can be, for example, a value at which the bucket 4c of the front working implement 4 deviates from the area of ​​the target object (for example, the tray area 14a), and is preset and stored in the memory. The smaller the threshold value is set, the more frequently update instructions are output from the control target value update instruction unit 6e to the control target value storage unit 6b.

[0041] When the threshold value is set based on the condition that the soil or the like discharged from the bucket 4c deviates from the tray area 14a, for example, the distance between the center of the toe of the bucket 4c and the center point 14c of the tray area 14a at the start of the soil discharge operation (bucket dump) is set as the soil discharge position deviation, and the movement amount and turning angle of the traveling body 5 at which the soil discharge position deviation of a preset distance occurs can be set as the threshold value. As an example, the set distance for the soil discharge position deviation can be set to a value of 50% of the width dimension of the bucket 4c. When the hydraulic excavator 1 loads soil into the dump truck 11, in order to efficiently fully load the dump truck 11, it is necessary to discharge the soil accurately at the center point 14c of the tray area 14a. If the bucket 4c deviates from the center point 14c during soil discharge, soil may spill from the tray, and the dump truck 11 may not be fully loaded or more soil discharges than necessary may be required to fully load the dump truck 11, resulting in a decrease in productivity. Therefore, setting the threshold value based on the size of the bucket 4c is a reasonable example for maintaining high productivity.

[0042] <Operation> Fig. 4 is a flowchart showing an example of a processing procedure by the control device 6. The processing in Fig. 4 is executed by the control device 6 while the control device 6 is energized.

[0043] When a start signal is received from a key switch (not shown) provided in the operator's cab 2 or from the remote operation device 100, the control device 6 starts the process of FIG. 4 as step S100.

[0044] In step S101, the control device 6 detects the dump truck 11 from the distance data obtained by measuring the distance around the vehicle body and received from the object detection device 8 by the control target value acquisition unit 6a.

[0045] In the next step S102, the control device 6 calculates a vector 14b that is a relative distance to the center point 14c of the tray area 14a of the dump truck 11 by the control target value acquisition unit 6a.

[0046] When the procedure proceeds to step S103, the control device 6 determines whether the moving body 5 is stopped and whether the movement or turning of the moving body 5 is detected by the relative information change detection unit 6d, and when the moving body 5 is displaced even though the moving body 5 is stopped, calculates the amount of displacement and transmits it to the control target value update instruction unit 6e. Specifically, step 103 includes a determination of whether the moving body 5 is stopped (step S103a) and a determination of whether the moving body 5 is displaced (step S103b). When the moving body 5 is intentionally driven based on the output signal of the travel sensor 10b (no), the control device 6 returns the procedure from step S103a to step S101, detects the dump truck 11, and recalculates the vector 14b. If the moving object 5 is not being driven intentionally (yes), the control device 6 calculates the position and orientation of the moving object 5 based on the output of the positioning device 9 or the object detection device 8, and determines whether they are different from the position and orientation of the moving object 5 currently stored in the memory (S103b). As a result, if the moving object 5 has been displaced (yes), the control device 6 advances the procedure from step S103b to step S104, and if the moving object 5 has not been displaced (no), the control device 6 skips step S103b to step S104 and advances the procedure to step S105.

[0047] When the procedure proceeds to step S104, the control device 6 executes the judgment of the above-mentioned formula 1 by the control target value update instruction unit 6e to judge whether or not the relative distance data currently held by the control target value holding unit 6b needs to be updated. If step S103b is performed multiple times while the running object 5 is currently stopped, the total value of the multiple displacement amounts is substituted for the displacement amount in formula 1. If the condition of formula 1 is not met and the relative distance data does not need to be updated (no), the control device 6 proceeds from step S104 to step S105. On the other hand, if the condition of formula 1 is met and the relative distance data needs to be updated (yes), the control device 6 proceeds from step S104 to step S106.

[0048] When the procedure proceeds to step S105, the control device 6 holds the relative distance data currently held in the control target value holding unit 6b as is.

[0049] When the procedure proceeds to step S106, the control device 6 transmits an instruction to update the relative distance data from the control target value update instruction unit 6e to the control target value storage unit 6b, transmits an instruction to recalculate the relative distance data from the control target value storage unit 6b to the control target value acquisition unit 6a, and updates the relative distance data currently stored in the control target value storage unit 6b with the relative distance data newly calculated by the control target value acquisition unit 6a. As the process of step S106, a process of returning the procedure to step S101 is illustrated in FIG.

[0050] If necessary, processing of step S106 is performed and the reliability of the relative distance data is confirmed in step S105, then the control device 6 proceeds to step S107, where it calculates control signals for the rotating body 3 and the front work machine 4 that realize automatic excavation and loading or semi-automatic excavation and loading based on the latest highly reliable relative distance data held by the control target value holding unit 6b, and outputs control signals to the drive devices 7a, 7b.

[0051] In the next step S108, the control device 6 determines whether or not to end operation of the hydraulic excavator 1, and if operation is to be continued (no), the procedure returns to step S103a, and if operation is to be ended (yes), the procedure in Fig. 2 ends. The control device 6 can determine whether or not to end operation based on, for example, a signal that is input when a key switch provided in the operator's cab 2 is turned off, or a signal that commands the end of operation that is transmitted from a remote control device.

[0052] By repeatedly executing the above steps S100-S108, the excavation and loading operation is repeated without recalculating the relative distance data as long as the running body 5 does not displace beyond the threshold value (step S107), and as a result, if the running body 5 is displaced beyond the threshold value, the relative distance data is recalculated and the excavation and loading operation is performed.

[0053] <Remote control device> As illustrated in FIG. 1, the elements corresponding to the cab 2 and the control device 6 may be located outside the body of the hydraulic excavator 1. The remote operation device 100 illustrated in FIG. 1 is an example of the cab 2 and the control device 6 installed outside the hydraulic excavator 1. The remote operation device 100 has an operation device (not shown) corresponding to the operation device provided in the cab 2 and a remote control device 101 corresponding to the control device 6, and is installed in a location other than the operation site of the hydraulic excavator 1, for example, a server room capable of wireless communication with the hydraulic excavator 1. An operator gets on the remote operation device 100 in the server room and operates the operation device while watching the camera image transmitted from the hydraulic excavator 1, and the hydraulic excavator 1 operates according to an operation signal transmitted from the remote control device 101 to the hydraulic excavator in response to the operation. The remote control device 101 can execute the same processes as the control device 6, except that the remote control device 101 transmits and receives input of output signals from various sensors and output of command signals to the driving devices 7a and 7b via wireless communication.

[0054] <Effects> When the hydraulic excavator 1 excavates the ground, the traveling body 5 slides along the ground and is pulled to the excavation site due to the reaction between the ground and the hydraulic excavator 1. Generally, the traveling body 5 is not driven during excavation and is therefore stationary, but the relative positions of the hydraulic excavator 1 and the dump truck 11 change unexpectedly due to the sliding of the traveling body 5, and the reference coordinate system 13 (Fig. 2) of the hydraulic excavator 1 moves in the on-site coordinate system 15 as shown by the thick arrow in Fig. 5.

[0055] However, since this movement of the reference coordinate system 13 is not based on an instruction from the operator or the control device 6, if the device distance data update process is not performed, the automatic loading control is performed in a state where the identified relative position is shifted from the actual relative position between the hydraulic excavator 1 and the dump truck 11. In other words, as shown in Fig. 5, the automatic loading control is performed in a state where the tray area 14a recognized by the control device is shifted from the actual tray position of the dump truck 11. In this case, soil and sand may spill from the dump truck 11, reducing productivity.

[0056] In contrast, in this embodiment, even if the hydraulic excavator 1 moves unintentionally due to an excavation reaction force, when a predetermined displacement of the unintended traveling body 5 is detected, the relative distance data is recalculated, so that high productivity can be maintained by highly accurate excavation and loading control based on highly reliable relative distance data. Furthermore, while a predetermined displacement of the unintended traveling body 5 is not detected, the excavation and loading control is repeatedly performed without calculating the relative distance data each time, and the calculation load of the control device 6 is reduced by suppressing the calculation frequency of the relative distance data, so that the hydraulic excavator 1 can be operated smoothly. Therefore, as described above, a certain level of reliability of the relative distance data is ensured at the time when the bucket 4c starts to move, so that the bucket 4c can be moved to the target position on a trajectory calculated in advance, and wasteful operation of the hydraulic excavator 1 can be reduced.

[0057] As described above, according to the hydraulic excavator 1 of this embodiment, it is possible to suppress discrepancies in the perception of the actual positional relationship with the dump truck 11, and to load soil and sand onto the transport vehicle with high accuracy while moving the bucket on a trajectory with minimal loss, thereby maintaining high productivity.

[0058] Second embodiment 6 is a flow chart showing an example of a processing procedure by a control device provided in a work machine according to a second embodiment of the present invention. The same processes as those in the first embodiment are given the same step numbers as in FIG. 4, and the explanations thereof will be omitted as appropriate.

[0059] This embodiment differs from the first embodiment in that the motion detection sensor 10a is used as a displacement sensor, and the need to update the relative distance data (data on the position of the target object) is determined based on the number of excavation operations detected by the motion detection sensor 10a while the traveling body 5 is stopped. Considering that the traveling body 5 may be displaced for each excavation operation, this embodiment converts the amount of displacement of the traveling body 5 into the number of excavation operations. Except for this point, this embodiment is similar to the first embodiment, including the hardware configuration.

[0060] In Fig. 4, steps S100-S103a and S105-S108 are the same as those in the first embodiment. In this embodiment, when the determination in step S103a is satisfied, the control device 6 shifts the procedure to step S104', and detects an excavation operation by the front work unit 4 based on a detection signal from the operation detection sensor 10a related to the operation of the front work unit 4 by the relative information change detection unit 6d, and when the number of excavation operations during the current stop of the traveling body 5 reaches a preset number set as a threshold value, it determines that the traveling body 5 has been displaced by more than the threshold value during the current stop of the traveling body 5. If the number of excavation operations is more than the set number (yes), the control device 6 shifts the procedure from step S104' to step S106 to update the relative distance data, and if the number of excavation operations does not reach the set number (no), the control device 6 shifts the procedure from step S104' to step S105 to hold the current relative distance data.

[0061] As sensors related to the operation of the front working implement 4, as described above, at least one of pressure sensors that detect the pressure in the bottom side oil chamber and rod side oil chamber of a hydraulic cylinder that drives a front working implement such as the boom cylinder 4d, an angle sensor that detects the angle of a driven member of the front working implement 4 such as the boom 4a, an IMU, an operation sensor that detects an operation signal, etc. can be used.

[0062] As an example, when a pressure sensor is used, it is possible to determine that an excavation operation has been performed based on the output signal of the pressure sensor during the last operation of the hydraulic excavator before execution of step S104' (step S107), for example, by detecting an excavation reaction force equal to or greater than a set value based on the oil chamber pressure of the arm cylinder 4e during arm crowding.When an angle sensor, IMU, or operation sensor is used, it is possible to determine the excavation operation based on the trajectory and operation pattern of the bucket 4c calculated based on the output signals of those sensors during operation of the hydraulic excavator.

[0063] The above-mentioned set number as a threshold value can be set by previously taking statistics on the amount of displacement of the traveling body 5 per excavation operation and determining the number of excavation operations at which the amount of displacement of the traveling body 5 reaches the threshold value.

[0064] In this embodiment as well, the same effects as in the first embodiment can be obtained.

[0065] Third embodiment 7 is a flow chart showing an example of a processing procedure by a control device provided in a work machine according to a third embodiment of the present invention. The same processes as in the first embodiment are given the same step numbers as in FIG. 4, and the explanation will be omitted as appropriate.

[0066] This embodiment differs from the first embodiment in that the motion detection sensor 10a is used as a displacement sensor, and whether or not the relative distance data (data on the position of the target object) needs to be updated is determined based on the presence or absence of a specific motion detected by the motion detection sensor 10a while the running object 5 is stopped. The specific motion is, for example, a motion that tilts the running object 5, and a representative example is a jacking-up motion.

[0067] When the amount of lifting operation of the boom 4a of the front work unit 4 is small during ground leveling operation, the bucket 4c is pressed against the ground, and the front of the traveling body 5 is lifted up by the reaction force between the front work unit 4 and the ground, resulting in a jack-up operation. When the traveling body 5 is inclined in this manner, the contact area between the traveling body 5 and the ground is reduced, and the traveling body is likely to slip on the ground due to the operation of the front work unit 4 and the rotating body 3, and the traveling body 5 moves or turns even though the traveling body 5 is not moving. When a specific operation that tilts the traveling body 5 is performed, such as this jack-up operation, there is a possibility that the traveling body 5 will be displaced (especially turn) beyond a threshold value. In this embodiment, taking this into consideration, when a specific operation that may cause the traveling body 5 to move significantly is detected, it is deemed that the traveling body 5 has been displaced beyond a threshold value. Except for this point, this embodiment, including the hardware configuration, is the same as the first embodiment.

[0068] In FIG. 4, steps S100-S103a and S105-S108 are the same as those in the first embodiment. In this embodiment, if the determination in step S103a is satisfied, the control device 6 shifts the procedure to step S104'', where the relative information change detection unit 6d detects a specific operation by the front working unit 4 based on a detection signal from the operation detection sensor 10a related to the operation of the front working unit 4, and if the specific operation is detected, determines that the traveling unit 5 has been displaced by a threshold value or more while the traveling unit 5 is currently stopped. If the specific operation is detected (yes), the control device 6 shifts the procedure from step S104'' to step S106 and updates the relative distance data, and if the specific operation is not detected (no), the control device 6 shifts the procedure from step S104'' to step S105 and holds the current relative distance data.

[0069] The sensors used to determine a specific operation can be at least one of a pressure sensor that detects the pressure in the bottom side oil chamber and the rod side oil chamber of the hydraulic cylinder that drives the front working machine such as the boom cylinder 4d, an operation sensor that detects an operation signal, an IMU that detects the acceleration of the rotating body 3 and the running body 5, a positioning device 9, an object detection device 8, etc.

[0070] As an example, when a pressure sensor or an operation sensor is used, if the pressure in the rod side oil chamber of the boom cylinder 4d (oil chamber to which pressurized oil is supplied when the boom is raised) falls below a set value while the boom is being raised, it can be inferred that an unintentional jacking-up operation has been performed and the bucket 4c is being pressed hard against the ground, based on the output signals from the pressure sensor and the operation sensor during the last operation of the hydraulic excavator before execution of step S104'' (step S107). Also, if the pressure in the rod side oil chamber of the boom cylinder 4d (oil chamber from which pressurized oil is pushed out when the boom is lowered) falls below a set value while the amount of boom lowering operation exceeds a set value, it can be inferred that an intentional jacking-up operation has been performed. When an IMU, positioning device 9, or object detection device 8 is used, a specific operation can be determined based on the inclination of the traveling body 5 calculated based on the output signals from these sensors while the hydraulic excavator is in operation.

[0071] In this embodiment as well, the same effects as in the first embodiment can be obtained.

[0072] (Modification) The above embodiments can be combined as appropriate. For example, when the first embodiment and the second embodiment are combined, if the determination in step S104 in FIG. 4 is not satisfied (no), a flow may be established in which step S104' (FIG. 6) is further executed. When the first embodiment and the third embodiment are combined, if the determination in step S104 in FIG. 4 is not satisfied (no), a flow may be established in which step S104" (FIG. 7) is further executed. When the three embodiments are combined, if the determination in step S104 in FIG. 4 is not satisfied (no), a flow may be established in which step S104' (FIG. 6) and step S104" (FIG. 7) are further executed. [Explanation of symbols]

[0073] 1...hydraulic excavator (working machine), 3...rotating body, 4...front working machine, 4c...bucket, 5...traveling body, 6...control device, 7...driving device, 8...object detection device (displacement sensor), 9...positioning device (displacement sensor), 10a...motion detection sensor (displacement sensor), 10b...traveling sensor, 12...specific area (object), 14a...tray area (object), 101...remote control device

Claims

1. A work machine including a traveling body, a rotating body rotatably provided on an upper portion of the traveling body, and a front work implement attached to the rotating body, an object detection device for detecting objects around the work machine; A travel sensor for detecting the movement of the travel object; A displacement sensor for detecting a displacement of the traveling body; a drive device that drives the traveling body, the rotating body, and the front working machine; a control device that controls the drive device based on detection results of the object detection device, the travel sensor, and the displacement sensor, The control device includes: Calculating the position of an object that serves as a reference for control of the traveling body, the rotating body, and the front working machine based on the detection signal from the object detection device; Controlling the rotating body and the front working machine based on the position of the object; Based on the detection signals of the travel sensor and the displacement sensor, if the travel object is displaced while the motion of the travel object is stopped, the position of the object is recalculated. A working machine characterized by:

2. 2. The work machine according to claim 1, The displacement sensor is at least one of a positioning device that acquires a position of the rotating body and the object detection device, The control device calculates a displacement amount of the moving object based on a detection signal of at least one of the positioning device and the object detection device. A working machine characterized by:

3. 2. The work machine according to claim 1, the displacement sensor is a motion detection sensor that detects a motion of the front working implement, The control device detects an excavation operation by the front working machine based on a detection signal from the operation detection sensor, and when the number of times of the excavation operation while the traveling body continues to be stopped reaches a preset number of times, it determines that the traveling body has been displaced to a threshold value or more while the traveling body continues to be stopped. A working machine characterized by:

4. 2. The work machine according to claim 1, the displacement sensor is a motion detection sensor that detects a motion of the front working implement, The control device detects a specific motion based on a detection signal from the motion detection sensor, and when the specific motion is detected, determines that the moving body has been displaced by a threshold value or more while the moving body is stopped. A working machine characterized by:

5. 4. The work machine according to claim 3, A work machine, wherein the threshold value is a value at which a bucket of the front work machine deviates from a region of the object.

6. A remote control device communicates with a work machine including a running body, a rotating body rotatably provided on an upper portion of the running body, a front working machine attached to the rotating body, an object detection device that detects surrounding objects, a running sensor that detects the operation of the running body, a displacement sensor that detects the displacement of the running body, and a drive device that drives the running body, the rotating body, and the front working machine, and remotely controls the drive device based on detection results of the object detection device, the running sensor, and the displacement sensor, calculating a position of an object that serves as a reference for control of the traveling body, the rotating body, and the front working machine based on a detection signal of the object detection device received from the work machine; generating control signals for the rotating body and the front work implement based on the position of the object and transmitting the control signals to the work machine; Based on the detection signals of the travel sensor and the displacement sensor received from the work machine, if the travel object is displaced while the operation of the travel object is stopped, the position of the object is recalculated.

13. A remote control device comprising:

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