Contact determination method, contact determination system, and program

Abstract

To provide a technique whereby a placed object can be shaped into a desired shape using a work machine, this contact determination method comprises: acquiring information relating to the position of at least one of one or more movable parts provided in the work machine (S11); and determining contact between the work machine and the object on the basis of the result of comparing the amount of change in the position of the movable part specified according to the position-related information, and a threshold value indicating an amount of change serving as a reference for determining contact between the work machine and the object (S12).　

Description

[Technical Field]

[0001] The present invention relates to a contact determination device, a contact determination system, a contact determination method, and a program. [Background technology]

[0002] In the construction industry, labor shortages and the transfer of skills due to factors such as the aging of on-site workers and a decrease in the number of young workers are becoming urgent issues. Therefore, there is technology that remotely controls the discharge of soil excavated by a work machine to assist the operator's skills. For example, Patent Document 1 discloses a control device that discharges excavated soil generated at a construction site or the like to a specified location. The control device disclosed in Patent Document 1 performs control to prohibit the output of a soil discharge operation signal when the direction in which a rotating body operated by a loading command signal faces is within a specified area. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2019-151972 Summary of the Invention [Problem to be solved by the invention]

[0004] The control device disclosed in Patent Document 1 can load earth and sand onto a cargo vehicle (such as a dump truck) without spilling the earth and sand by discharging the earth and sand at a position where the cargo vehicle (such as a dump truck) is located.

[0005] On the other hand, when a cargo vehicle loaded with earth and sand etc. travels on public roads, the shape (package) of the loaded earth and sand etc. needs to be adjusted. For example, the earth and sand needs to be loaded in an even manner so that it does not spill while traveling. However, while the technology disclosed in Patent Document 1 makes it possible to load the discharged earth onto a cargo vehicle without spilling it, it does not take into consideration the shape of the discharged earth.

[0006] Therefore, even if earth and sand are loaded onto a cargo vehicle using the technology disclosed in Patent Document 1, if the earth and sand is not shaped, there may be cases where measures to prevent the earth and sand from spilling while the vehicle is moving are insufficient. Furthermore, in cases where the operator cannot visually determine the shape of the load, as in the case of automated driving, or when an operator lacks the skills to determine the shape of the load, it is not possible to perform operations such as adjusting the position of the earth and sand to be discharged.

[0007] One aspect of the present invention has been made in consideration of the above-mentioned problems, and one example of its purpose is to provide a technology that can shape a placed object into a desired shape using a work machine. [Means for solving the problem]

[0008] (delete)

[0009] A contact determination method according to one aspect of the present invention includes acquiring information relating to the position of at least one of one or more movable parts provided on a work machine, and determining contact between the work machine and an object based on the result of comparing an amount of change in the position of the movable part identified in accordance with the information relating to the position with a threshold indicating an amount of change that serves as a criterion for determining contact between the work machine and an object.

[0010] A contact determination system according to one aspect of the present invention comprises an acquisition means for acquiring information relating to the position of at least one of one or more movable parts of a work machine, and a determination means for determining contact between the work machine and an object based on the result of comparing the amount of change in the position of the movable part identified in accordance with the information relating to the position with a threshold indicating the amount of change that serves as a criterion for determining contact between the work machine and the object.

[0011] A contact determination program according to one aspect of the present invention is a program for causing a computer to function as a contact determination device, and causes the computer to function as: an acquisition means for acquiring information regarding the position of at least one of one or more movable parts of a work machine; and a determination means for determining contact between the work machine and an object based on the result of comparing the amount of change in the position of the movable part identified in accordance with the information regarding the position with a threshold indicating the amount of change that serves as a criterion for determining contact between the work machine and an object. [Effects of the Invention]

[0012] According to one aspect of the present invention, a placed object can be shaped into a desired shape using a work machine. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a schematic diagram illustrating a configuration of a collision determination system according to a first exemplary embodiment of the present invention. [Figure 2] 1 is a schematic diagram showing the configuration of a backhoe and a bulldozer applied to a collision determination system according to a first exemplary embodiment. FIG. [Figure 3] 1 is an example of a graph showing the change in the position of a backhoe bucket over time. [Figure 4] 1 is an example of a flowchart illustrating a flow of a collision determination method according to the first exemplary embodiment. [Figure 5] FIG. 1 is a block diagram illustrating a configuration of a collision determination device according to an exemplary embodiment. [Figure 6] FIG. 10 is a block diagram showing the configuration of a collision determination system according to a second exemplary embodiment. [Figure 7] FIG. 10 is a schematic diagram showing a working state of the backhoe according to the second exemplary embodiment. [Figure 8] This is a schematic diagram showing the procedure for leveling soil using a backhoe bucket. [Figure 9] 10 is a graph showing the actual movement of the bucket when descent control is performed. [Figure 10]10 is an example of a flow diagram showing the flow of a motion control method executed by a motion control device according to an exemplary embodiment 2. FIG. [Figure 11] 10 is an example of a flowchart illustrating the flow of a contact determination method executed by a contact determination device according to an exemplary embodiment 2. [Figure 12] 10 is a schematic diagram illustrating a contact determination method according to a first modification of the second exemplary embodiment. FIG. [Figure 13] 10 is a schematic diagram showing a contact determination method according to a second modification of the second exemplary embodiment. FIG. [Figure 14] FIG. 10 is a block diagram showing the configuration of a collision determination system according to an exemplary embodiment 3. [Figure 15] FIG. 10 is a block diagram showing the configuration of a collision determination device according to an exemplary embodiment 4. [Figure 16] FIG. 10 is a block diagram showing the configuration of a contact determination system including a work machine according to a fifth exemplary embodiment. [Figure 17] FIG. 10 is a configuration diagram for realizing a collision determination device by software. DETAILED DESCRIPTION OF THE INVENTION

[0014] Exemplary Embodiment 1 A first exemplary embodiment of the present invention will be described in detail with reference to the drawings. This exemplary embodiment is a basic form of the exemplary embodiments described below.

[0015] (Configuration of Contact Detection System 1) 1 is a schematic diagram showing the configuration of a contact determination system 1 according to exemplary embodiment 1. In this exemplary embodiment, a contact determination system 1 that determines whether or not a moving part of a backhoe 40 has come into contact with earth and sand, which is the object of work, will be described.

[0016] As shown in the figure, the contact determination system 1 includes an acquisition unit 11 and a determination unit 12. The acquisition unit 11 and the determination unit 12 are communicatively connected to a controller 44 of the backhoe 40 via a communication network 50. The communication network 50 is a wireless (e.g., 4G, 5G, local 5G, LTE, Wifi (registered trademark), etc.) or wired (e.g., LAN, optical fiber, etc.) network, and may be an intranet used within a work area or the Internet. In FIG. 1, the acquisition unit 11 and the determination unit 12 are connected to the controller 44 via the wireless communication network 50. The acquisition unit 11 and the determination unit 12 are, respectively, one form of an acquisition means and a determination means recited in the claims.

[0017] The acquisition unit 11 acquires information regarding the position of at least one of one or more movable parts provided in the backhoe 40. The position may be a rotational position or a translational position. For example, the rotational position is the rotation angle of the movable part when the movable part is a rotating member. For example, the translational position is the amount of translation of the movable part when the movable part is a translating member. As an example, this information is detected by a sensor described later and transmitted to the acquisition unit 11.

[0018] The position according to this exemplary embodiment may be a relative position based on a reference point on the backhoe 40, or may be an absolute position in a space including the backhoe 40 and the object. Information about the position is information from which the relative or absolute position of the movable part of the backhoe 40 can be derived. Information about the position is information from which the position of the movable part (hereinafter, the position of the movable part may also be referred to as the posture) can be derived. The movable parts of the backhoe 40 will be described later.

[0019] The determination unit 12 determines whether the work machine has come into contact with an object based on a comparison result between the amount of change in the position of the movable part, determined based on the position information, and a threshold value indicating the amount of change that serves as a criterion for determining whether the backhoe 40 has come into contact with the object (earth and sand). The amount of change in position refers to the amount of change in the relative or absolute position of the movable part. Specifically, it may be an amount equivalent to the first-order derivative of the position data (e.g., the amount of movement velocity of the movable part) or an amount equivalent to the second-order derivative of the position data (e.g., the amount of movement acceleration of the movable part). The threshold value is used to determine whether or not there has been contact between the work machine and the object, and can be set according to various conditions, such as the type of work machine, the type of work, and the type and characteristics of the object. Therefore, a threshold value that is predetermined for each condition based on experiments or estimations can be used. "In advance" may be set before the contact determination is made. For example, this may be set at any time, such as during initial setup for autonomous operation (e.g., during calibration when the work machine is brought to the work site), during input during inspection before work begins, or during maintenance or inspection. The contact determination system 1 may also include a calculation unit (not shown) that calculates the amount of change in position.

[0020] Contact in the contact detection is not limited to surface contact, but also includes the insertion of a rod-shaped member into an object or the insertion of a surface-shaped member into an object. Specifically, it also includes the insertion of a fork-shaped member or blade-shaped member attached to the tip of the arm of a work machine for ground leveling or construction into an object such as soil or sand.

[0021] The controller 44 is mounted on the backhoe 40 and controls the operation of the backhoe 40 based on the received operation control signal. "Mounted" refers to being built into the backhoe 40 or being retrofitted to a typical commercially available backhoe (e.g., by placing a small computer on the passenger seat). For example, if the backhoe 40 is designed for autonomous operation, it is built in when it is sold commercially. However, if the backhoe is designed for on-board operation, a small computer with a built-in control program may be retrofitted as the controller 44. When retrofitting a backhoe that is operated by a person on board, an attachment may be attached to a lever, and the backhoe may be operated by operating the lever through commands from the attachment. Note that the controller 44 may be installed near the backhoe (within a range where communication is possible via a communication network) and transmit control signals to the backhoe 40 from there. The operation control signals are signals that control the operation of each part of the backhoe 40, and are generated by a motion control device (described later) and transmitted to the controller 44.

[0022] (Backhoe configuration) The configuration of a backhoe 40 to which the contact detection system 1 is applied will be described with reference to the drawings. 201 in FIG. 2 is a schematic diagram showing the configuration of the backhoe 40. Normally, the backhoe 40 is not operated by a person on board, but performs work under remote control using a controller 44. Remote control includes a method in which a worker in a different location operates the backhoe by sending a signal to the controller 44, or a method in which an autonomous control device in a different location performs autonomous control by sending a signal to the controller 44.

[0023] As shown in 201 in Fig. 2, the backhoe 40 includes a traveling section 49, a main body 45 attached to the traveling section 49, and a controller 44. The backhoe 40 includes various sensors (not shown) for detecting the attitude, i.e., the position, of each part of the backhoe 40. Note that instead of or in addition to the sensors that detect the attitude, i.e., the position, of each part of the backhoe 40, a camera or a distance measuring device may be placed in the work area, and the attitude or position of each part of the backhoe 40 may be detected from information obtained by these devices.

[0024] The travel unit 49 is a travel unit that enables the backhoe 40 to move forward, backward, turn right, and turn left. The travel unit 49 travels using, for example, an endless track belt. The movable unit includes a main body 45, a boom 41 (first movable unit) connected to the main body 45, an arm 42 (second movable unit) connected to the tip of the boom 41, and a bucket 43 (third movable unit) connected to the tip of the arm 42. The acquisition unit 11 acquires information regarding the rotational position of at least any one of these movable units.

[0025] The main body 45 can rotate on the running part 49 within a plane that is approximately parallel to the ground. "Approximately parallel" does not only mean perfectly parallel, but also means that unevenness or inclination within a certain range of error is considered to be essentially parallel. When the backhoe 40 is on level ground, the plane that is parallel to the ground is a horizontal plane, so hereinafter, for convenience, a plane that is approximately parallel to the ground will be referred to as a "horizontal plane."

[0026] The boom 41 can rotate back and forth around the boom axis 46 in a plane that is approximately perpendicular to the horizontal plane. "Approximately perpendicular" does not only mean completely perpendicular, but also means that something that is inclined within a certain range of error is considered to be substantially perpendicular. The arm 42 can rotate back and forth around the arm axis 47 in the same rotation plane as the boom 41. The bucket 43 can rotate back and forth around the bucket axis 48 in the same rotation plane as the arm 42. The posture of the backhoe 40 changes as each part of the movable part rotates. The movable parts refer to the main body 45, boom 41, arm 42, and bucket 43.

[0027] The spatial position of each movable part can be derived from its swing angle. For example, the position of arm shaft 47 relative to a predetermined position of traveling part 49 can be derived from the swing angle of main body 45 and the swing angle of boom 41. The position of bucket shaft 48 can be derived from the position of arm shaft 47 and the swing angle of arm 42. The position of the bottom of bucket 43 can be derived from the position of bucket shaft 48 and the swing angle of bucket 43.

[0028] The various sensors each detect information relating to the position of the movable parts of the backhoe 40. Information relating to the position of the movable parts includes, for example, but is not limited to, the rotation angle of each part of the movable parts. In this exemplary embodiment, each of the sensors detects the rotation angle of the main body 45, the boom 41, the arm 42, or the bucket 43. The rotation angle (position information) detected by the sensor is transmitted to the acquisition unit 11.

[0029] Specifically, the sensor that detects the rotation angle of the main body 45 is, for example, a gyro sensor. This sensor may also be an encoder that detects the number of rotations of the motor that rotates the main body 45. The sensor that detects the rotation angle of the boom 41 is an inclination sensor or gyro sensor that detects the angle of the boom 41 from the horizontal plane. This sensor may also be an encoder that detects the travel distance of the rod of the hydraulic cylinder that rotates the boom 41. Similarly, the sensor that detects the rotation angle of the arm 42 is, for example, an inclination sensor, gyro sensor, or encoder that detects the angle of the arm 42 with respect to the boom 41. The sensor that detects the rotation angle of the bucket 43 is, for example, an inclination sensor, gyro sensor, or encoder that detects the angle of the bucket 43 with respect to the arm 42.

[0030] The controller 44 has a processor, memory, and a communication interface (none of which are shown). The controller 44 reads and executes a program stored in the memory to acquire detected values ​​from the sensors and transmits the acquired detected values ​​to an operation control device (not shown) via the communication interface. The controller 44 also reads and executes a program stored in the memory to control each part of the backhoe 40 in accordance with operation control signals received from the operation control device (not shown) via the communication interface.

[0031] For example, the controller 44 rotates part or all of the main body 45, the boom 41, the arm 42, and the bucket 43 in accordance with the operation control signal. For example, when part or all of the main body 45, the boom 41, and the arm 42 are rotated, the position of the bucket 43 changes, and the bucket 43 moves. Also, for example, when the bucket 43 is rotated, the bucket 43 performs an operation of scooping up or releasing earth and sand, which is the target object TO.

[0032] (Bulldozer configuration) In this exemplary embodiment, the applicable work machine is not limited to the backhoe 40, but can also be a bulldozer, for example. The configuration of a bulldozer 40a to which the contact determination system 1 is applied will be described with reference to the drawings. Reference numeral 202 in FIG. 2 is a schematic diagram showing the configuration of the bulldozer 40a. Like the backhoe 40, the bulldozer 40a is not normally operated by a person on board, and performs work under remote control using a controller 44.

[0033] 2, the bulldozer 40a includes a traveling section 49, a main body 45a attached to the traveling section 49, and a controller 44. The bulldozer 40a includes various sensors (not shown) for detecting the attitude, i.e., the position, of each section of the bulldozer 40a.

[0034] The following describes the differences from the backhoe 40 described above.

[0035] The movable parts of bulldozer 40a include a main body 45a, a cylinder 41a (first movable part) and a rod 42a (second movable part) attached to the main body 45a, and a blade 43a (third movable part) attached to the tip of rod 42a.

[0036] The bulldozer 40a translates the rod 42a back and forth to move the blade 43a back and forth. This allows the bulldozer 40a to push aside earth and sand, which is the target object TO, and perform ground leveling, etc. In addition, the blade 43a can be moved up and down by rotating the cylinder 41a up and down with a hydraulic cylinder (not shown). Alternatively, the blade 43a itself may be rotated up and down with a hydraulic cylinder (not shown). The movable parts of the bulldozer 40a refer to the cylinder 41a, the rod 42a, and the blade 43a.

[0037] The various sensors detect the state of the bulldozer 40a. The state of the bulldozer 40a is, for example, but not limited to, the rotation angle or translation amount of each movable part. In this exemplary embodiment, the sensors are a sensor that detects the rotation angle of the main body 45a, a sensor that detects the rotation angle of the cylinder 41a, a sensor that detects the translation amount of the rod 42a, and a sensor that detects the rotation angle of the blade 43a. These sensors are similar to the sensors used in the backhoe 40. That is, the sensor that detects the rotation angle can be a gyro sensor or an encoder, etc. The sensor that detects the translation amount can be an encoder, etc. that detects the movement amount of the rod 42a. The rotation angle or translation amount detected by the sensors is transmitted to the acquisition unit 11.

[0038] As described above, the work machine to which the contact determination system 1 is applied is not limited to the backhoe 40, but includes other work machines that excavate, shape, collect, or transport objects, such as excavators, bulldozers, and wheel loaders. Furthermore, the objects handled by the work machine according to this exemplary embodiment are not limited to earth and sand, but include granular materials such as grains and gravel, powders such as cement, and amorphous objects such as rubble. Furthermore, the objects are not limited to amorphous objects, but may be immovable objects such as structures or the ground, for which it is desired to determine whether or not there is contact with a moving part.

[0039] (position change amount) Next, a specific example of the amount of change in position will be described with reference to the drawings. For example, consider the case where the bucket 43 of the backhoe 40 is used to level the soil loaded on a cargo vehicle. The soil that has just been dumped onto the cargo vehicle is higher near the center and lower toward the periphery, or the soil remains in a state where large unevenness remains. Therefore, an operation control unit (not shown) presses the bottom of the bucket 43 against the higher mounds of soil to level the soil so as to reduce the difference in elevation.

[0040] Specifically, the operation control unit transmits to the controller 44 a descent control signal for lowering the bucket 43, which has been positioned above the convex portion of the soil and sand in advance, at a constant speed. Upon receiving this descent control signal, the controller 44 executes control for lowering the bucket 43. The control for lowering the bucket 43 can be executed by controlling the rotational position of the arm 42 or the boom 41 to change.

[0041] FIG. 3 is an example of a graph showing the change in the position of the bucket 43 over time. The vertical axis of FIG. 3 represents the height position of the bucket 43 (the rotational position of the arm 42 or the boom 41), and the horizontal axis represents time. When the controller 44 lowers the bucket 43 from above the soil toward the soil at a constant speed, the bucket 43 descends at a controlled constant speed from time t1 until time t2. However, when the bottom surface of the bucket 43 comes into contact with the soil at time t2, the bucket 43 presses against the soil, and the speed of descent changes (specifically, decreases) due to the reaction force from the soil. In other words, the change in the position of the bucket becomes gentler from time t2. In other words, the slope becomes smaller after time t2.

[0042] The controlled descent speed from time t1 to time t2 is defined as v1, and the descent speed from time t2 to time t3 is defined as v2. The descent speeds v1 and v2 are examples of the aforementioned amount of change in position. The collision detection system 1 includes a calculation unit (not shown) that calculates the descent speeds v1 and v2, which are the amount of change in position, from information about the position (height information). Note that the descent speed is the speed in the direction in which the position decreases, so both v1 and v2 are positive values.

[0043] (Contact determination) Here, the determination unit 12 may determine that the bucket 43 and the earth and sand are in contact when v2 is less than or equal to the threshold value T1. However, the threshold value T1 is set to a value smaller than the controlled descent speed v1.

[0044] Furthermore, the determination unit 12 may determine that the bucket 43 and the earth and sand are in contact when the descent speed v2, which is the amount of change in position, is less than or equal to the threshold value T1 within the time interval T that is the criterion for determining the contact between the bucket 43 and the earth and sand. In the example shown in FIG. 3, the time interval from time t2 to time t3 is T, the descent speed during this time interval T is v2, and v2 < T1. Therefore, the determination unit 12 determines that the bucket 43 and the earth and sand are in contact. The determination result of the determination unit 12 is transmitted to the operation control device. When the operation control unit receives the determination result that the bucket 43 and the earth and sand are in contact, as an example, it transmits a signal to stop the descent control of the bucket 43 to the controller 44. When the controller 44 receives the signal to stop the descent control of the bucket 43 from the operation control device, it stops the descent control of the bucket 43. Therefore, in the example shown in FIG. 3, the position of the bucket does not change after time t3. The time interval T that is the criterion for determining the contact between the bucket 43 and the earth and sand can be set in advance. "In advance" is as described in the explanation of the threshold value indicating the amount of change of the movable part.

[0045] The threshold value T1 is set to a value smaller than the controlled descent speed v1. The descent speed v1 can be grasped in advance as to what value it will be according to the operation control signal by the operation control device and the specifications of the hydraulic cylinder in the backhoe 40, etc.

[0046] As described above, the contact detection system 1 according to this exemplary embodiment is configured to include an acquisition means for acquiring information about the position of at least one of one or more movable parts of the work machine, and a determination means for determining contact between the work machine and an object based on the results of comparing the amount of change in the position of the movable part identified in accordance with the information about the position with a threshold value indicating the amount of change that serves as a reference for determining contact between the work machine and the object. Therefore, the contact detection system 1 according to this exemplary embodiment calculates the amount of change in position from information about the position of the movable part, and determines contact between the work machine and the object based on this result. This ensures that contact can be determined reliably, resulting in the effect of allowing a placed object to be shaped into a desired shape using the work machine.

[0047] (Contact judgment method) Next, a contact determination method S1 according to this exemplary embodiment will be described with reference to the drawings. Fig. 4 is an example of a flow diagram showing the flow of the contact determination method S1 executed by the contact determination system 1 according to this exemplary embodiment.

[0048] As shown in the figure, the contact determination method S1 includes the following steps. In step S11, the acquisition unit 11 acquires information regarding the position of at least one of one or more movable parts provided on the work machine. For example, the acquisition unit 11 acquires information regarding the position of the bucket 43 of the backhoe 40. The content of the position and the information regarding the position is the same as that described for the acquisition unit 11 of the contact determination system 1.

[0049] In step S12, the determination unit 12 determines whether the work machine has come into contact with the object based on the result of comparing the amount of change in the position of the movable part, which is specified based on the information related to the position, with a threshold value indicating the amount of change that serves as a criterion for determining whether the work machine has come into contact with the object. For example, the determination unit 12 determines that the bucket 43 has come into contact with the object, i.e., earth and sand, if the descent speed of the bucket 43, which is the amount of change in position calculated from the information related to the position of the bucket 43, is equal to or less than the threshold value indicating the amount of change that serves as a criterion for determining whether the bucket 43 has come into contact with earth and sand. Specific examples of the amount of change in position and the determination of contact are the same as those described for the determination unit 12 of the contact determination system 1.

[0050] In addition, the determination unit 12 may determine that the bucket 43 has come into contact with the object, which is soil or sand, if the amount of change in position is less than or equal to a threshold value during a time interval that serves as a reference for determining contact between the work machine and the object.

[0051] As described above, the contact detection method S1 according to this exemplary embodiment is configured to acquire information about the position of at least one of one or more movable parts of the work machine, and determine contact between the work machine and an object based on the results of comparing the amount of change in the position of the movable part specified in accordance with the information about that position with a threshold indicating the amount of change that serves as a reference for determining contact between the work machine and the object. Therefore, the contact detection method S1 according to this exemplary embodiment has the effect of being able to shape a placed object into a desired shape using the work machine.

[0052] (Contact determination device) Next, the contact determination device 100 according to this exemplary embodiment will be described with reference to the drawings. Fig. 5 is a block diagram showing the configuration of the contact determination device 100 according to this exemplary embodiment.

[0053] As shown in the figure, the contact detection device 100 includes an acquisition unit 11 that acquires information about the position of at least one of one or more movable parts equipped on the work machine, and a determination unit 12 that performs contact detection between the work machine and an object based on the results of comparing the amount of change in position of the movable part specified in accordance with the information about the position with a threshold value that indicates the amount of change that serves as a reference for determining contact between the work machine and the object. The configurations of the acquisition unit 11 and the determination unit 12 are the same as those of the acquisition unit 11 and determination unit 12 of the contact detection system 1, and therefore a description thereof will be omitted here. Furthermore, the content of the position and the information about the position, as well as specific examples of the amount of change in position and contact detection, are the same as those described for the acquisition unit 11 and determination unit 12 of the contact detection system 1.

[0054] As an example, the contact determination device 100 determines contact between the bucket of a backhoe, which is a work machine, and earth and sand, which is the object of work. Specifically, the acquisition unit 11 acquires information about the position of the bucket (e.g., the turning angle) detected by various sensors arranged on the backhoe, for example. Then, the amount of change in the bucket position is calculated from the information about the bucket position, and based on the result of comparing the amount of change with a threshold, it determines whether the bucket has come into contact with the object.

[0055] The contact determination device 100 may include a calculation unit (not shown) that calculates the amount of change in position from information related to the position. In this case, the determination unit 12 refers to the descent speed of the bucket, which is the amount of change in the bucket position calculated by the calculation unit, and determines that the bucket has come into contact with the object, which is earth and sand, if the descent speed of the bucket is equal to or less than a threshold value.

[0056] In addition, the determination unit 12 may determine that the bucket has come into contact with the object, which is earth and sand, if the amount of change in position is less than a predetermined threshold value during a time interval that serves as a reference for determining contact between the work machine and the object.

[0057] As described above, the contact determination device 100 according to this exemplary embodiment is configured to include an acquisition means for acquiring information about the position of at least one of one or more movable parts of the work machine, and a determination means for determining contact between the work machine and an object based on the results of comparing the amount of change in the position of the movable part specified in accordance with the information about that position with a threshold indicating the amount of change that serves as a reference for determining contact between the work machine and the object. Therefore, the contact determination device 100 according to this exemplary embodiment has the effect of being able to shape a placed object into a desired shape using the work machine.

[0058] As described above, in this exemplary embodiment, contact with an object is determined based on the amount of change in the position of at least one of one or more movable parts provided in the backhoe 40. Here, it is also possible to configure the backhoe 40 to be capable of acquiring the excavation reaction force or the amount of change in the excavation reaction force, and to perform contact determination based on the excavation reaction force or the amount of change in the excavation reaction force. However, since the detection accuracy of the excavation reaction force is generally lower than the detection accuracy of the position of the movable part, as described in this exemplary embodiment, contact determination with an object can be performed more accurately based on the amount of change in the position of the movable part.

[0059] Furthermore, as described above, in this exemplary embodiment, contact with an object is determined based on the result of comparing the amount of change in the position of at least one of one or more movable parts provided in the backhoe 40 with a threshold value. Here, the threshold value is different from the so-called target control amount for moving the movable part of the backhoe 40 along the target trajectory, and is a value determined in advance for contact determination. In other words, the threshold value can be determined in advance depending on the object, etc. that is the target of contact determination.

[0060] Exemplary Embodiment 2 (Configuration of contact detection system 1A) A second exemplary embodiment of the present invention will be described in detail with reference to the drawings. Note that components having the same functions as those described in the first exemplary embodiment are given the same reference numerals, and their description will be omitted as appropriate.

[0061] 6 is a block diagram showing the configuration of a contact determination system 1A according to exemplary embodiment 2. As shown in the figure, the contact determination system 1A includes a contact determination device 100A and an operation control device 150.

[0062] The contact determination device 100A and the operation control device 150 are connected to a controller 44 of a backhoe 40, which is a work machine, via a communication network 50 so as to be able to communicate information. The backhoe 40 is equipped with a controller 44. The communication network 50 and the backhoe 40 have the same configuration as the communication network 50 and the backhoe 40 described in the first exemplary embodiment. In this exemplary embodiment, the operation of each device will be described using as an example a case where the backhoe 40 performs work to level earth and sand loaded on a dump truck 60.

[0063] Note that the components of the contact determination device 100A and the motion control device 150 do not have to be contained in a single device, but may be separated and located in multiple devices. This is also true for other exemplary embodiments. For example, in FIG. 6, the object position acquisition unit 151 and the motion control unit 153 of the motion control device 150 may be located in the motion control device 150, and the trajectory generation unit 152 may be located in the cloud. Trajectory generation may then be performed on the cloud, and the trajectory information may be transmitted to the motion control unit 153.

[0064] The contact determination device 100A includes an acquisition unit 110, a determination unit 120A, and a memory unit 130. The acquisition unit 110 acquires a signal transmitted from a sensor mounted on the backhoe 40. The sensor detects at least one of information on the rotation angle and the translation amount, which is information on the position of the movable part of the backhoe 40, and transmits the information to the acquisition unit 110.

[0065] The determination unit 120A determines whether the movable part has come into contact with an object. The determination unit 120A includes a change amount calculation unit 121, an elapsed time calculation unit 122, and a contact determination unit 123. The change amount calculation unit 121 calculates the amount of change in the position of the movable part of the backhoe 40. The change amount calculation unit 121 may be the calculation unit that calculates the amount of change in position described in exemplary embodiment 1. The elapsed time calculation unit 122 calculates how long the amount of time during which the amount of change in the position of the movable part of the backhoe 40 continuously satisfies a condition related to a predetermined threshold has continuously elapsed. The contact determination unit 123 determines whether the movable part has come into contact with an object by referring to the calculated amount of change in position and the time during which the amount of change has continued.

[0066] The memory unit 130 records the movable part position information MPI and the threshold information THI. The movable part position information MPI is information relating to the position of the movable part of the backhoe 40. Information relating to the position of the movable part is sequentially transmitted from the sensor to the acquisition unit 110, and the acquisition unit 110 sequentially records the information as movable part position information MPI. Note that the memory unit 130 may store the movable part position information MPI or the threshold information THI, etc., in association with the reception time or absolute time.

[0067] The threshold information THI is information relating to at least one of a threshold value and a time interval. In this exemplary embodiment, as the threshold information THI, vt is recorded in the storage unit 130 as a threshold value for the bucket descent speed when leveling earth and sand using the bucket 43 of the backhoe 40, and T is recorded as a time interval for which the bucket descent speed continues. As an example, the threshold information THI may be set manually by an operator, or information on another site or device may be acquired via a communication network.

[0068] (Generation of target trajectory) The trajectory generation unit 152 of the motion control device 150 generates a target trajectory for at least one of one or more movable parts, which extends beyond the surface of the object as seen from the at least one movable part. As an example, the motion control device 150 generates a target trajectory for the bucket 43, which extends beyond (inside) the surface of the soil and sand TO as seen from the bucket 43. The motion control unit 153 of the motion control device 150 generates a control signal for moving the bucket 43 along the target trajectory and sends it to the controller 44. The motion control device 150 corresponds to the motion control device described in the first exemplary embodiment.

[0069] Specifically, the movement control device 150 includes an object position acquisition unit 151, a trajectory generation unit 152, and a movement control unit 153. The movement control device 150 is one form of the movement control means described in the claims.

[0070] The object position acquisition unit 151 acquires the position of the object. As an example, the object position acquisition unit 151 acquires information indicating the position of the object from a sensor arranged near the work site. The sensor is, for example, a three-dimensional sensor (3D sensor) such as a three-dimensional LiDAR (Light Detection and Ranging), a stereo camera, or a TOF (Time of Flight) camera, or a depth camera. The object position acquisition unit 151 derives the position of the object (an absolute position in the work space, or a relative position with respect to the backhoe 40) using distance information acquired from the three-dimensional LiDAR.

[0071] The trajectory generation unit 152 generates a target trajectory (hereinafter simply referred to as "trajectory") for moving the movable part (e.g., bucket 43) of the backhoe 40 based on the acquired position of the object and the work content. The trajectory may be a straight trajectory or a trajectory including a curve. The bucket 43 can also be moved linearly by adjusting the rotation angles of the boom 41 and the arm 42. Note that if the acquired position of the object is an absolute position, the absolute position of the backhoe 40 must also be acquired. For example, by using 3D LiDAR or the like, it is possible to acquire both the absolute position of the object within the work area and the absolute position of the backhoe 40. The work content defines the operations to be performed by the backhoe, such as bucket movement, rotation of the upper rotating body (main body) between the excavation object and the loaded cargo, excavation (determining the excavation point (excavation position), moving the bucket to the excavation position, scooping and lifting the object), dumping, leveling, etc. Note that the work content is different from the operation along the trajectory generated by the trajectory generating unit, and refers to the content of the work that is the purpose of the work machine, and an operation control signal for controlling the operation for that purpose is generated separately. In other words, an operation control signal according to the operation to be executed next is transmitted to the controller 44. Specifically, based on the information on the position of the target object, the excavation point (excavation position) is determined, the bucket is moved to the excavation position, the target object is scooped up, lifted, etc., and the next operation control signal is generated.

[0072] The operation control unit 153 generates a control signal for controlling the backhoe 40 so that the movable part moves along the generated trajectory, and transmits the signal to the controller 44.

[0073] (Backhoe 40 operation and collision detection) Next, an example of work performed by the backhoe 40 will be described. FIG. 7 is a schematic diagram showing the working state of the backhoe 40 according to this exemplary embodiment. In this exemplary embodiment, the backhoe 40 performs leveling work on the object TO (earth and sand) loaded on the dump truck 60. The leveling work is a work to reduce unevenness in the earth and sand to make it as flat as possible. Specifically, it is a work to press the convex parts of the earth and sand from above with the bottom surface of the bucket 43 of the backhoe 40. The structure of the movable parts of the backhoe 40 is as described in the exemplary embodiment 1.

[0074] The leveling work will be described in detail with reference to Fig. 8. Fig. 8 is a schematic diagram showing the procedure for leveling the earth and sand TO using the bucket 43 of the backhoe 40.

[0075] As shown in 801 in FIG. 8, first, the bucket 43 is placed above the convex portion of the soil / sand TO. At this time, the attitude of the bucket 43 is controlled so that the bottom surface of the bucket 43 is approximately horizontal. The placement position is the start point of the trajectory ORB along which the bucket 43 will move, which has been generated in advance by the trajectory generation unit 152. The trajectory generation unit 152 references the work content indicating the work of pressing the soil / sand TO using the bucket 43 (leveling work) and the position of the convex portion of the soil / sand TO acquired by the target object position acquisition unit 151, and generates in advance the start point and end point TP along which the bucket 43 will move, as well as a route indicated by a dotted line connecting the start point and end point TP. Such a route including the start point and end point is called the trajectory ORB.

[0076] Next, as shown in 802 in Figure 8, the control signal sent by the motion control device 150 causes the bucket 43 to descend along the trajectory ORB toward the end point TP. As shown in the figure, the bucket 43 comes into contact with a convex portion of the soil TO midway along the trajectory ORB, but the motion control device 150 continues to control the descent toward the end point TP. Through this control, the soil TO is pressed and leveled by the bucket 43.

[0077] Next, if a predetermined condition is satisfied, the determination unit 120A determines that the bucket 43 has come into contact with the earth and sand TO and transmits this to the operation control device 150. When the operation control device 150 receives the determination result that the bucket 43 has come into contact with the earth and sand TO, it stops the descent control. Then, for example, it starts ascent control to raise the bucket 43 along a new ascending trajectory ORB. As a result, as shown in 803 in FIG. 8, the bucket 43 rises along the new ascending trajectory ORB toward the terminal point TP. Details of the determination process performed by the determination unit 120A will be described later.

[0078] (Determination based on the difference between the target motion control and the actual motion) Figure 9 is a graph showing the actual movement of bucket 43 when such descent control is performed. The vertical axis of Figure 9 represents the height (m) of bucket 43, and the horizontal axis represents time. Before time t1, motion control device 150 controls bucket 43 to descend at a speed of v0 toward a height of 2.7 (m), which is the control target point (end point). As a result, bucket 43 descends at the speed of v0 and approaches the height of the control target point.

[0079] At time t1, the motion control device 150 acquires information that the height of the bucket 43 has fallen below 2.7 (m), which is the control target point, and changes the height of the control target point to 1.58 (m), and further sets the descent speed to v1, which is greater than v0. As a result, the bucket 43 continues to descend at the descent speed v1 from t1. Note that there is a slight time lag between the start of control and the actual appearance of control movement.

[0080] After time t2, the descent speed of the bucket 43 slows down to v2. This means that the bottom of the bucket 43 has come into contact with the soil TO. The descent speed v2 after t2 is equal to or less than a threshold vt of the amount of change in position that is set in advance as a criterion for determining contact. Then, between t2 and t3, the descent speed is equal to or less than the threshold vt. The threshold vt is set to, for example, 0.2 (m / sec). Note that the threshold vt is the descent speed of the bucket 43, but it may also be determined by, for example, the swing angular velocity of the boom 41. The threshold for the swing angular velocity of the boom 41 can be set to, for example, 1 (° / sec) in the downward direction.

[0081] Furthermore, the time interval from t2 to t3 is the time interval T that is preset as a criterion for contact determination. That is, this means that the amount of change v2 in position is equal to or less than the threshold value vt during the time interval T. The time interval T is set to, for example, 0.5 (seconds).

[0082] If the descent speed of the bucket 43 becomes equal to or less than a set threshold value vt within a predetermined time interval T, the determination unit 120A determines that the bucket 43 has come into contact with the earth and sand TO and transmits the determination result to the operation control device 150. Upon receiving the determination result, the operation control device 150 stops controlling the descent of the bucket 43. Therefore, there is almost no change in the height of the bucket 43 from t3 onwards. Note that although the height of the bucket 43 has dropped slightly due to the collapse of earth and sand, for example, the descent control of the bucket 43 is not being performed.

[0083] Although the amount of change in position described above is exemplified as the descending velocity, the amount of change in position is not limited to the translational velocity, and translational acceleration, turning angular velocity, turning angular acceleration, etc. However, when calculating acceleration, errors due to noise in the sensor signal become large, so it is preferable to reduce noise using, for example, a filter.

[0084] As described above, in the contact detection system 1A according to this exemplary embodiment, the motion control device 150 is configured to include a trajectory generation unit 152 that generates a target trajectory for at least one of one or more movable parts, the target trajectory extending beyond the surface of the object as viewed from at least one of the movable parts. In other words, whether or not the movable part has come into contact with the object is determined while the movable part is moving along the generated target trajectory. Therefore, the contact detection system 1A according to this exemplary embodiment eliminates the risk that the movable part will not reach the object and reduces the risk that the movable part will continue moving even after coming into contact with the object, allowing the movable part to be stopped at an appropriate position. This provides the effect of enabling a placed object to be shaped into a desired shape using a work machine.

[0085] (Operation control method) The above-described operation control method for a work machine will now be described with reference to the drawings. Fig. 10 is an example of a flow diagram showing the flow of the operation control method S130A executed by the operation control device 150.

[0086] As shown in the figure, the operation control method S130A includes the following steps. In step S131, the acquisition unit 110 acquires the position of an object. For example, the acquisition unit 110 acquires information indicating the position of the earth and sand that is the object being worked on by the backhoe from a sensor placed near the work site (any position that provides a bird's-eye view of the work site, and may be, for example, a ceiling, pillar, or beam). Note that if the position information of the object indicates the absolute position of the object, the acquisition unit 110 must also acquire information indicating the absolute position of the work machine.

[0087] In step S132, the trajectory generating unit 152 generates a target trajectory. Specifically, the trajectory generating unit 152 generates a target trajectory that extends further back than the surface of the object as seen from at least one of the movable parts. For example, when a backhoe uses a bucket to perform shaping work on soil and sand, the trajectory generating unit 152 refers to position information of the soil and generates a target trajectory that extends further back (inside) than the surface of the soil and sand as seen from the bucket.

[0088] In step S133, the operation control unit 153 controls the operation of the bucket. Specifically, the operation control unit 153 generates an operation control signal for moving the bucket along the target trajectory and transmits it to the controller of the backhoe. The controller controls the movement of the bucket based on the received operation control signal.

[0089] In step S134, the operation control unit 153 determines whether or not a determination result indicating that the work machine has come into contact with the object has been received from the contact determination device 100A. The contact determination process executed by the contact determination device 100A will be described later.

[0090] If the determination result that the work machine has come into contact with the object has not been received (step S134: NO), the flow returns to step S133.

[0091] If a determination result that the work machine has come into contact with the object is received (step S134: YES), the flow proceeds to step S135, where the operation control unit 153 ends bucket operation control (stops the bucket). This ends the operation control process. Note that if it is determined that contact has occurred and control of moving the bucket 43 along the target trajectory has ended, the next operation control may be performed. For example, in the case of work to level soil and sand, the bucket 43 may be raised and moved to the next leveling position to perform the leveling work, or if the backhoe's next work content is not notified, the bucket may be placed on the ground and placed in a standby position.

[0092] By using the above-described operation control method, a placed object can be shaped into a desired shape using a work machine.

[0093] (Contact judgment method) Next, a contact determination method S100A for determining whether or not a work machine has come into contact with an object will be described with reference to the drawings. Fig. 11 is an example of a flow diagram showing the flow of the contact determination method S100A executed by the contact determination device 100A.

[0094] As shown in the figure, the contact determination method S100A includes the following steps. In step S111, the acquisition unit 110 acquires the current (latest) position information of the moving part of the work machine. For example, the acquisition unit 110 sequentially acquires detection values ​​from a rotation angle sensor, encoder, etc., arranged on the backhoe 40 while the work machine is in operation. "Sequential acquisition" means that the detection value at that time is acquired every certain unit time. The unit time may be, for example, several milliseconds to several tens of milliseconds. Note that the elapsed time calculation unit 122 starts measuring the elapsed time from the point when the position information of the moving part is acquired for the first time after the start of the contact determination process.

[0095] In step S112, the acquisition unit 110 stores the acquired position of the movable part. Specifically, the acquisition unit 110 records the acquired detection value in the storage unit 130 as sequential movable part position information MPI.

[0096] In step S121, the change amount calculation unit 121 of the determination unit 120A acquires the current movable part position information and the movable part position information one unit time ago from the position information recorded in the storage unit .

[0097] In step S122, the change amount calculation unit 121 calculates the amount of change in the movable part position per unit time from the acquired movable part position information. For example, the change amount calculation unit 121 calculates the moving speed of the movable part by subtracting the movable part position one unit time ago from the current movable part position and dividing the result by the unit time.

[0098] In step S123, the contact determination unit 123 determines whether the calculated change is equal to or less than a threshold value. For example, the contact determination unit 123 determines whether the calculated travel speed is equal to or less than a threshold value stored in the storage unit 130. This threshold value may be set according to the work content of the work machine or the object. Examples of the work content include compacting the surface height of the soil loaded on a dump truck until it is lower than the height of the dump vessel (frame), or reducing the maximum height difference of the unevenness of the soil surface to a predetermined value or less. For example, the threshold value may be set taking into account the strength of the loading area. For example, in the case of compacting the soil loaded on a dump truck, the threshold value may be set small (e.g., 0.1 m / s) taking into account the strength of the dump truck. On the other hand, in the case of compacting the soil loaded in a loading area, such as in landfill work, the threshold value may be set large (e.g., 0.2 m / s). Examples of the object include soil, crushed stone, industrial waste, etc.

[0099] In step S123, if it is determined that the calculated amount of change is not equal to or less than the threshold value (S123: NO), the process proceeds to step S125. Then, in step S125, the elapsed time from the current time to the start of measurement is reset, and the process returns to step S111.

[0100] If it is determined in step S123 that the calculated change amount is equal to or less than the threshold value (S123: YES), the process proceeds to step S124. In step S124, elapsed time calculation unit 122 updates the elapsed time, and the flow proceeds to step S126.

[0101] In step S126, the elapsed time calculation unit 122 determines whether the elapsed time is equal to or greater than a threshold value. The threshold value here refers to the above-mentioned preset time interval T. This threshold value may be set depending on the type of work performed by the work machine or the target object. If it is determined in step S126 that the elapsed time is not equal to or greater than the threshold value (S126: NO), the process returns to step S111. At this time, the elapsed time is not reset.

[0102] If it is determined in step S126 that the elapsed time is equal to or greater than the threshold (S126: YES), the process proceeds to step S127, where the contact determination unit 123 determines that the movable part and the object have come into contact with each other, and the contact determination process ends. This determination result is transmitted to the operation control device 150.

[0103] As described above, the contact detection method according to this exemplary embodiment is configured to calculate the amount of change in the position of the movable part based on the position information of the movable part, and compare the amount of change with a set threshold to determine whether or not the movable part has come into contact with an object. In other words, the above method determines whether or not the movable part has come into contact with an object while the movable part is moving along the generated target trajectory. Therefore, the contact detection method according to this exemplary embodiment eliminates the risk that the movable part will not reach the object, reduces the risk that the movable part will continue moving even after coming into contact with the object, and allows the movable part to be stopped at an appropriate position. This provides the effect of enabling a placed object to be shaped into a desired shape using a work machine.

[0104] (Collision detection variation 1) Next, a first modification of the contact determination method according to the second exemplary embodiment will be described with reference to the drawings. Fig. 12 is a schematic diagram showing the first modification of the contact determination method according to the first exemplary embodiment.

[0105] As shown in the figure, there are cases where control is performed to keep the bucket 43 of the backhoe 40 in contact with the ground without the operator having to board and operate it. In this case, if the bucket 43 is pressed too hard against the ground, a problem occurs in that the front part of the backhoe 40 will lift up. Therefore, it is necessary to accurately determine whether the bucket 43 has touched the ground. In such cases, contact between the bucket 43 and the ground is determined.

[0106] First, the target object position acquisition unit 151 of the operation control device 150 acquires position information of the bucket 43 before it touches down and the ground where it will be placed. Next, the trajectory generation unit 152 generates a target trajectory whose end point is a position where the bucket 43 is deeper than the ground (into the ground). The reason for using a position deeper than the ground (into the ground) as the end point is that if a target trajectory is generated with the ground position as the end point, there is a risk that a position that does not touch the ground will be set as the end point due to measurement errors in the ground position, etc. The end point may be slightly deeper than the ground (into the ground); for example, in the case of a 30-ton class backhoe, it may be set to a position when the bucket is 20 cm underground.

[0107] Next, the operation control unit 153 generates an operation control signal for moving the bucket 43 along the generated target trajectory and transmits it to the controller 44. The controller 44, which has received the operation control signal, controls the movement of the bucket 43 in accordance with the operation control signal.

[0108] The control to move the bucket 43 is executed, for example, by changing the swing angle of the boom shaft 46 so that the swing angle of the boom 41 with respect to the ground becomes smaller. Then, the determination unit 120A calculates the amount of change in the swing angle from the swing angle information of the boom shaft 46, and when the calculated amount of change becomes smaller than a set threshold amount of change, determines that the bucket 43 has touched the ground, and transmits the determination result to the operation control device 150. In response to this, the operation control device 150 ends the ground contact operation control.

[0109] In this case, the threshold value may be, for example, an amount smaller than the controlled amount of change, because it is sufficient to determine when the bucket 43 will no longer move. By controlling in this manner, the grounding operation of the bucket 43 can be performed with high accuracy.

[0110] (Collision detection variation 2) Next, a second modification of the contact determination method according to the second exemplary embodiment will be described with reference to the drawings. Fig. 13 is a schematic diagram showing the contact determination method according to the second modification.

[0111] In the second modification, when the bucket 43 is used to excavate or shape the earth and sand TO, contact between the bucket 43 and the earth and sand TO is determined.

[0112] When excavating or shaping the soil TO, the blade portion (or teeth portion) 43b at the tip of the bucket 43 is inserted into the soil TO. If the blade portion 43b is not inserted into the soil TO by enough, the excavation or shaping will not be performed sufficiently. Conversely, if the blade portion 43b is inserted into the soil TO by too much, the bucket 43 may not move or the front part of the backhoe 40 may lift up. Therefore, it is necessary to insert the bucket 43 into the soil TO by an appropriate amount. In such cases, contact between the bucket 43 and the soil TO can be determined so that the blade portion 43b can be inserted into the soil TO at an appropriate position.

[0113] First, the object position acquisition unit 151 of the operation control device 150 acquires position information of the bucket 43 and the surface of the soil and sand TO before the bucket 43 is inserted into the soil and sand TO. Next, the trajectory generation unit 152 generates a target trajectory whose end point is a position where the blade portion 43b is deeper (inside) than the surface of the soil and sand TO. The end point may be sufficiently deeper than the ground surface (into the ground); for example, in the case of a 30-ton class backhoe, the end point may be a position 2 m underground.

[0114] Next, the operation control unit 153 generates an operation control signal for moving the bucket 43 along the generated target trajectory and transmits it to the controller 44. The controller 44, which has received the operation control signal, controls the movement of the bucket 43 in accordance with the operation control signal. At this time, the orientation of the bucket 43 is such that the blade portion 43b faces the surface of the soil and sand TO.

[0115] The control for moving the bucket 43 is performed, for example, by changing the swing angle of the arm shaft 47 so that the bucket 43 approaches the soil TO. The determination unit 120A then calculates the amount of change in the swing angle from the swing angle information of the arm shaft 47, and when the calculated amount of change is smaller than a set threshold value for the amount of change, determines that the bucket 43 has been properly inserted into the soil TO, and transmits the determination result to the operation control device 150.

[0116] In response to this, the motion control device 150 ends the inserting motion control and starts excavation motion control for rotating the bucket 43 or ground leveling motion control for moving the bucket 43 back and forth.

[0117] In this case, the threshold value is set based on a pre-measured change in position when the bucket 43 is properly inserted into the soil TO. By controlling in this manner, the bucket 43 can be inserted into the soil TO with high precision.

[0118] Exemplary Embodiment 3 A third exemplary embodiment of the present invention will be described in detail with reference to the drawings. Note that components having the same functions as those described in the first and second exemplary embodiments are denoted by the same reference numerals, and their description will not be repeated.

[0119] 14 is a block diagram showing the configuration of a contact determination system 1B according to this exemplary embodiment. As shown in the figure, the contact determination system 1B includes a contact determination device 100B and an operation control device 150.

[0120] The contact determination device 100B and the operation control device 150 are connected to a backhoe 40, which is a work machine, via a communication network 50 so as to be able to communicate information. The backhoe 40 is equipped with a controller 44. The communication network 50 and the backhoe 40 have the same configurations as the communication network 50 and the backhoe 40 described in exemplary embodiment 1. In this exemplary embodiment, the contact determination system 1B can also be used, for example, when the backhoe 40 performs work to level soil loaded on a dump truck 60, as described in exemplary embodiment 2.

[0121] The contact determination device 100B includes an acquisition unit 110, a determination unit 120B, and a memory unit 130. The acquisition unit 110 acquires a signal transmitted from a sensor mounted on the backhoe 40. The sensor detects at least one of information on the rotation angle and the translation amount, which is information on the position of the movable part of the backhoe 40, and transmits the information to the acquisition unit 110.

[0122] The acquisition unit 110 further acquires information about the work content of the backhoe 40 or the object of work by the backhoe 40. This information is referenced when the threshold setting unit 124, which will be described later, sets at least one of a threshold and a time interval.

[0123] The determination unit 120B determines whether the movable part has come into contact with an object. The determination unit 120B includes a change amount calculation unit 121, an elapsed time calculation unit 122, a contact determination unit 123, and a threshold setting unit 124. The change amount calculation unit 121, the elapsed time calculation unit 122, and the contact determination unit 123 have the same configurations as the change amount calculation unit 121, the elapsed time calculation unit 122, and the contact determination unit 123 described in the exemplary embodiment 2. The threshold setting unit 124 sets at least one of a threshold for the amount of change in position and a time interval according to the work content of the backhoe 40 or the object of the work acquired by the acquisition unit 110. The threshold setting unit 124 is one form of the setting means recited in the claims.

[0124] The threshold setting unit 124 may be a threshold setting model trained by machine learning to use various conditions such as the work content and work conditions as input data and to output an optimal threshold. For example, an expert may be asked to perform work using an actual work machine while changing the type and properties of the object, and data such as the amount of change in the position of the movable part at which the operation of moving the movable part is terminated may be obtained, to create training data, which may then be used to train the threshold setting model.

[0125] The storage unit 130 records the movable part position information MPI and the threshold information THI. The movable part position information MPI is as described in the exemplary embodiment 2. The threshold information THI is information related to at least one of the threshold and the time interval set by the threshold setting unit 124.

[0126] The threshold values ​​and time intervals are determined in advance depending on the type of work machine, the work content of the work machine, the properties of the work object, the work environment, etc., and at least one of the threshold values ​​and time intervals paired with such various conditions is recorded in the memory unit 130 as threshold value information THI.

[0127] The operation control device 150 includes an object position acquisition unit 151, a trajectory generation unit 152, and an operation control unit 153. The object position acquisition unit 151, the trajectory generation unit 152, and the operation control unit 153 have the same configurations as the object position acquisition unit 151, the trajectory generation unit 152, and the operation control unit 153 described in the second exemplary embodiment.

[0128] As described above, in the contact detection system 1B according to this exemplary embodiment, the acquisition unit 110 further acquires information about the work content of the work machine or the object. The determination unit 120B is further configured to include a threshold setting unit 124 that sets at least one of a threshold and a time interval according to the work content or the object acquired by the acquisition unit 110. Therefore, the contact detection system 1B according to this exemplary embodiment can determine whether or not a contact has occurred between the work machine and the object by comparing the amount of change in the position of the movable part with at least one of a threshold and a time interval. Furthermore, the threshold or time interval is set with reference to the work content of the work machine or the information about the object. Therefore, the contact detection system 1B according to this exemplary embodiment has the advantage of being able to more accurately determine whether or not a contact has occurred compared to a method that detects the position of the object, calculates the distance between the movable part and the object, and determines whether or not contact has occurred based on whether or not the object has moved that distance.

[0129] Exemplary Embodiment 4 A fourth exemplary embodiment of the present invention will be described in detail with reference to the drawings. Note that components having the same functions as those described in the first to third exemplary embodiments are denoted by the same reference numerals, and their description will not be repeated.

[0130] 15 is a block diagram showing the configuration of a contact determination device 100C according to this exemplary embodiment. As shown in the figure, the contact determination device 100C includes the contact determination device 100B and an operation control device 150.

[0131] The contact determination device 100C includes an acquisition unit 110, a determination unit 120C, and a memory unit 130. The acquisition unit 110 acquires a signal transmitted from a sensor mounted on the backhoe 40. The sensor detects at least one of information on the rotation angle and the translation amount, which is information on the position of the movable part of the backhoe 40, and transmits the information to the acquisition unit 110.

[0132] The contact determination device 100C is connected to a backhoe 40, which is a work machine, so as to be able to communicate information with it via a communication network 50. The backhoe 40 is equipped with a controller 44. The communication network 50 and the backhoe 40 have the same configurations as the communication network 50 and the backhoe 40 described in exemplary embodiment 1. In this exemplary embodiment, the contact determination device 100C can also be used, for example, when the backhoe 40 performs work to level soil loaded on a dump truck 60, as described in exemplary embodiment 2.

[0133] The determination unit 120C includes a change amount calculation unit 121, an elapsed time calculation unit 122, a contact determination unit 123, a threshold setting unit 124, an object position acquisition unit 151, a trajectory generation unit 152, and an operation control unit 153.

[0134] The change amount calculation unit 121, the elapsed time calculation unit 122, the contact determination unit 123, and the threshold setting unit 124 have the same configuration as the change amount calculation unit 121, the elapsed time calculation unit 122, the contact determination unit 123, and the threshold setting unit 124 included in the determination unit 120B described in exemplary embodiment 3.

[0135] The object position acquisition unit 151, the trajectory generation unit 152, and the operation control unit 153 have the same configuration as the object position acquisition unit 151, the trajectory generation unit 152, and the operation control unit 153 included in the operation control device 150 described in exemplary embodiment 3.

[0136] That is, the contact determination device 100C according to this exemplary embodiment has a configuration in which the components of the operation control device 150 are included in the determination unit 120B of the contact determination device 100B described in the third exemplary embodiment.

[0137] As described above, the contact determination device 100C according to this exemplary embodiment employs the following configuration. That is, the trajectory generation unit 152 generates a target trajectory for at least one of one or more movable units, the target trajectory extending beyond the surface of the object as viewed from the at least one movable unit. The operation control unit 153 generates an operation control signal for moving the movable unit along the target trajectory. During this movement, the contact determination unit 123 determines that the movable unit has come into contact with the object if the amount of change in the position of the movable unit is equal to or less than the threshold set by the threshold setting unit 124. Then, the operation control unit 153 generates an operation control signal for stopping the movement of the movable unit.

[0138] With the above configuration, it is determined whether the movable part has come into contact with the object while it is moving along the generated target trajectory. This eliminates the risk that the movable part will not reach the object and reduces the risk that the movable part will continue moving even after coming into contact with the object, allowing the movable part to be stopped at an appropriate position. This provides the effect of enabling the placed object to be shaped into a desired shape using a work machine.

[0139] Exemplary Embodiment 5 A fifth exemplary embodiment of the present invention will be described in detail with reference to the drawings. Note that components having the same functions as those described in the first to fourth exemplary embodiments are denoted by the same reference numerals, and their description will not be repeated.

[0140] 16 is a block diagram showing the configuration of a contact determination system according to this exemplary embodiment. As shown in the figure, the contact determination system according to this exemplary embodiment includes a storage unit 140, a motion control device 150, and a backhoe 40, which is a work machine.

[0141] The configuration of the storage unit 140, the operation control device 150, and the communication network 50 is the same as that of the storage unit 140 described in the second exemplary embodiment. 130 , the configuration of the operation control device 150 and the communication network 50 is similar.

[0142] The backhoe 40 includes a controller 44 and a contact determination device 100. The contact determination device 100 has the same configuration as described in the exemplary embodiment 1. The contact determination device 100 and the controller 44 are connected to a storage unit 140 and an operation control device 150 via a communication network 50 so as to be able to communicate information.

[0143] The acquisition unit 11 of the contact determination device 100 acquires information indicating at least one of the rotational position and translational position of the movable part of the backhoe 40. This information is detected by a sensor (not shown) and transmitted to the acquisition unit 11 via wired or wireless connection. The determination unit 12 of the contact determination device 100 determines whether the backhoe 40 has come into contact with the object, i.e., earth and sand, based on the result of comparing the amount of change in the position of the movable part of the backhoe 40 with a preset threshold value. The result of the contact determination is transmitted to the operation control unit 153 of the operation control device 150 via the communication network 50. When the operation control unit 153 receives the determination result that the backhoe 40 has come into contact with earth and sand, it generates an operation control signal to stop movement control of the movable part of the backhoe 40 and transmits it to the controller 44.

[0144] As described above, the contact determination system according to this exemplary embodiment employs a configuration in which the backhoe 40, which is a work machine, is provided with the contact determination device 100. This allows the placed object to be shaped into a desired shape using the work machine.

[0145] (Variation 3) In exemplary embodiment 5, the contact determination device 100 provided in the backhoe 40 is the contact determination device 100 described in exemplary embodiment 1, and includes an acquisition unit 11 and a determination unit 12. However, the contact determination device provided in the backhoe 40 is not limited to this, and may be the contact determination device 100A, 100B, or 100C described in exemplary embodiments 2, 3, and 4. In this case, the storage unit 140 shown in FIG. 16 does not need to be provided. Furthermore, when the contact determination device 100C is used, the storage unit 140 and the operation control device 150 shown in FIG. 16 do not need to be provided.

[0146] [Software implementation example] Some or all of the functions of the contact determination devices 100, 100A, 100B, and 100C (hereinafter referred to as "contact determination devices 100, etc.") may be realized by hardware such as an integrated circuit (IC chip), or by software.

[0147] In the latter case, the contact determination device 100 and the like are realized, for example, by a computer that executes instructions of a program, which is software that realizes each function. An example of such a computer (hereinafter referred to as computer C) is shown in FIG. 17. The computer C includes at least one processor C1 and at least one memory C2. The memory C2 stores a program P for operating the computer C as the contact determination device 100 and the like. In the computer C, the processor C1 reads and executes the program P from the memory C2, thereby realizing each function of the contact determination device 100 and the like.

[0148] The processor C1 may be, for example, a central processing unit (CPU), a graphics processing unit (GPU), a digital signal processor (DSP), a micro processing unit (MPU), a floating point number processing unit (FPU), a physics processing unit (PPU), a microcontroller, or a combination thereof. The memory C2 may be, for example, a flash memory, a hard disk drive (HDD), a solid state drive (SSD), or a combination thereof.

[0149] The computer C may further include a RAM (Random Access Memory) for expanding the program P during execution and for temporarily storing various data. The computer C may also include a communication interface for transmitting and receiving data to and from other devices. The computer C may also include an input / output interface for connecting input / output devices such as a keyboard, mouse, display, and printer.

[0150] Furthermore, the program P can be recorded on a non-transitory tangible recording medium M that can be read by the computer C. Such a recording medium M can be, for example, a tape, a disk, a card, a semiconductor memory, or a programmable logic circuit. The computer C can acquire the program P via such a recording medium M. The program P can also be transmitted via a transmission medium. Such a transmission medium can be, for example, a communication network or broadcast waves. The computer C can also acquire the program P via such a transmission medium.

[0151] [Appendix 1] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. For example, embodiments obtained by appropriately combining the technical means disclosed in the above-described embodiments are also included in the technical scope of the present invention.

[0152] [Appendix 2] Some or all of the above-described embodiments can also be described as follows: However, the present invention is not limited to the following described aspects.

[0153] (Appendix 1) A contact detection method including: acquiring information relating to the position of at least one of one or more movable parts provided on a work machine; and determining contact between the work machine and an object based on the result of comparing an amount of change in the position of the movable part specified in accordance with the information relating to the position with a threshold indicating an amount of change that serves as a criterion for determining contact between the work machine and an object.

[0154] According to the above configuration, contact can be reliably determined, and therefore the placed object can be shaped into a desired shape using a work machine.

[0155] (Appendix 2) 2. The contact determination method of claim 1, further comprising calculating an amount of change in the position.

[0156] According to the above configuration, the amount of change in position is calculated and contact is determined based on this, so that contact can be determined reliably.

[0157] (Appendix 3) 3. The contact determination method according to claim 1, wherein the criteria for determining contact include that the amount of change in position is equal to or less than the threshold value.

[0158] According to the above configuration, the amount of change in position is compared with a threshold value that indicates the amount of change that serves as a reference for determining whether the work machine has come into contact with an object. By confirming an appropriate amount of change in position in advance through experiments or the like and setting the threshold value, it is possible to more reliably determine whether the work machine has come into contact with an object.

[0159] (Appendix 4) A contact determination method as described in Appendix 3, wherein the criteria for determining contact include the amount of change in position being less than or equal to the threshold value during a time interval that is a criterion for determining contact between the work machine and an object.

[0160] According to the above configuration, the amount of change in position is compared with a threshold value indicating the amount of change that serves as the reference for determining contact between the work machine and an object during a time interval that serves as the reference for determining contact between the work machine and an object. As a result, even if the amount of change falls below the threshold due to an accidental event, it does not affect the contact determination. This allows for more reliable contact determination.

[0161] (Appendix 5) 5. A contact determination method according to claim 4, further comprising: acquiring information relating to the work content of the work machine or the object; and setting at least one of the threshold value and the time interval according to the work content or the object.

[0162] According to the above configuration, at least one of the threshold value and the time interval is set by referencing information about the work content of the work machine or the object, thereby making it possible to more reliably determine contact.

[0163] (Appendix 6) A contact determination method as described in any one of Appendices 1 to 5, wherein the at least one movable part is a first movable part connected to the main body of the work machine, a second movable part connected to the first movable part, or a third movable part connected to the second movable part, and the acquiring step acquires information regarding the rotational position of the at least one movable part.

[0164] According to the above configuration, it is possible to more reliably determine whether a rotating movable part of a work machine has come into contact with an object.

[0165] (Appendix 7) The method according to any one of claims 1 to 5, further comprising generating a target trajectory of the at least one of the one or more movable parts, the target trajectory extending beyond the surface of the object as viewed from the at least one movable part. 6 10. A contact determination method according to any one of the above.

[0166] According to the above configuration, it is possible to prevent the movable part from not reaching the target object or from being pressed excessively against the target object.

[0167] (Appendix 8) A contact determination system comprising: an acquisition means for acquiring information relating to the position of at least one of one or more movable parts of a work machine; and a determination means for determining contact between the work machine and an object based on the result of comparing the amount of change in the position of the movable part specified in accordance with the information relating to the position with a threshold indicating the amount of change that serves as a criterion for determining contact between the work machine and an object.

[0168] According to the above configuration, the same effect as that of Supplementary Note 1 can be obtained.

[0169] (Appendix 9) 9. The collision determination system according to claim 8, further comprising a calculation means for calculating the amount of change in the position.

[0170] According to the above configuration, the same effect as that of Supplementary Note 2 can be obtained.

[0171] (Appendix 10) 10. The contact determination system according to claim 8, wherein the criteria for determining contact include that the amount of change in position is equal to or less than the threshold value.

[0172] According to the above configuration, the same effect as that of Supplementary Note 3 can be obtained.

[0173] (Appendix 11) A contact determination system as described in Appendix 10, wherein the criteria for determining contact include the amount of change in position being less than or equal to the threshold value during a time interval that is a criterion for determining contact between the work machine and an object.

[0174] According to the above configuration, the same effect as that of Supplementary Note 4 can be obtained.

[0175] (Appendix 12) The contact determination system described in Appendix 11, wherein the acquisition means further acquires information regarding the work content of the work machine or the object, and further includes setting means for setting at least one of the threshold value and the time interval according to the work content or the object.

[0176] According to the above configuration, the same effect as that of Supplementary Note 5 can be obtained.

[0177] (Appendix 13) A contact determination system as described in any one of Appendices 8 to 12, wherein the at least one movable part is a first movable part connected to the main body of the work machine, a second movable part connected to the first movable part, or a third movable part connected to the second movable part, and the acquisition means acquires information regarding the rotational position of the at least one movable part.

[0178] According to the above configuration, the same effect as that of Supplementary Note 6 can be obtained.

[0179] (Appendix 14) 14. The contact determination system according to any one of appendices 8 to 13, further comprising an operation control means for generating a target trajectory for at least one of the one or more movable parts, the target trajectory extending beyond the surface of the object as viewed from the at least one movable part.

[0180] According to the above configuration, the same effect as that of Supplementary Note 7 can be obtained.

[0181] (Appendix 15) A contact determination device comprising: an acquisition means for acquiring information relating to the position of at least one of one or more movable parts of a work machine; and a determination means for determining contact between the work machine and an object based on the result of comparing the amount of change in the position of the movable part specified in accordance with the information relating to the position with a threshold indicating the amount of change that serves as a criterion for determining contact between the work machine and an object.

[0182] According to the above configuration, the same effect as that of Supplementary Note 1 can be obtained.

[0183] (Appendix 16) 16. The collision determination device according to claim 15, further comprising a calculation means for calculating an amount of change in the position.

[0184] According to the above configuration, the same effect as that of Supplementary Note 2 can be obtained.

[0185] (Appendix 17) 17. The contact determination device according to claim 15, wherein the criteria for determining contact include that the amount of change in position is equal to or less than the threshold value.

[0186] According to the above configuration, the same effect as that of Supplementary Note 3 can be obtained.

[0187] (Appendix 18) A contact determination device as described in Appendix 17, wherein the criteria for determining contact include the amount of change in position being less than or equal to the threshold value during a time interval that is a criterion for determining contact between the work machine and an object.

[0188] According to the above configuration, the same effect as that of Supplementary Note 4 can be obtained.

[0189] (Appendix 19) The contact determination device according to claim 18, wherein the acquisition means further acquires information relating to the work content of the work machine or the object, and further includes setting means for setting at least one of the threshold value and the time interval according to the work content or the object.

[0190] According to the above configuration, the same effect as that of Supplementary Note 5 can be obtained.

[0191] (Appendix 20) The contact determination device according to any one of appendices 15 to 19, wherein the at least one movable part is a first movable part connected to the main body of the work machine, a second movable part connected to the first movable part, or a third movable part connected to the second movable part, and the acquisition means acquires information regarding the rotational position of the at least one movable part.

[0192] According to the above configuration, the same effect as that of Supplementary Note 6 can be obtained.

[0193] (Appendix 21) 21. The contact determination device according to any one of appendices 15 to 20, further comprising an operation control means for generating a target trajectory for at least one of the one or more movable parts, the target trajectory extending beyond the surface of the object as viewed from the at least one movable part.

[0194] According to the above configuration, the same effect as that of Supplementary Note 7 can be obtained.

[0195] (Appendix 22) A program for causing a computer to function as a contact determination device, the program causing the computer to function as: an acquisition means for acquiring information relating to the position of at least one of one or more movable parts of a work machine; and a determination means for determining contact between the work machine and an object based on the result of comparing the amount of change in the position of the movable part specified in accordance with the information relating to the position with a threshold indicating the amount of change that serves as a criterion for determining contact between the work machine and an object.

[0196] According to the above configuration, the same effect as that of Supplementary Note 1 can be obtained.

[0197] [Appendix 3] Some or all of the above-described embodiments can also be expressed as follows.

[0198] A contact determination device includes at least one processor. The processor executes an acquisition process for acquiring information regarding the position of at least any one of one or more movable parts of a working machine, a determination process for determining contact between the working machine and an object based on a comparison result between the amount of change in the position of the movable part specified according to the information regarding the position and a threshold value indicating the amount of change serving as a criterion for determining contact between the working machine and the object.

[0199] Note that this contact determination device may further include a memory, and a program for causing the processor to execute the acquisition process and the determination process may be stored in this memory. Further, this program may be recorded on a non-transitory tangible computer-readable recording medium.

Explanation of Signs

[0200] 1, 1A, 1B… Contact determination system 11… Acquisition unit 12… Determination unit 40… Backhoe 40a… Bulldozer 41… Boom 42… Arm 43… Bucket 44… Controller 45, 45a… Body 46… Boom axis 47… Arm axis 48… Bucket axis 49… Travel unit 50… Communication network 60… Dump truck 100, 100A, 100B, 100C… Contact determination device 110… Acquisition unit 120A, 120B, 120C… Determination unit 121… Amount-of-change calculation unit 122… Elapsed-time calculation unit 123… Contact determination unit 130… Storage unit 150… Operation control device 151… Object position acquisition unit 152...Trajectory generation part 153...Motion control unit

Claims

1. acquiring information relating to the position of at least one of one or more movable parts provided in the work machine; acquiring information about the work content of the work machine and the object of work performed by the work machine; setting a threshold value serving as a criterion for determining contact between the work machine and the object, for the amount of change in the position of the movable part specified in accordance with the information about the position, and a time interval serving as a criterion for determining contact between the work machine and the object, in accordance with the work content and the object; and determining whether the work machine has come into contact with the object based on a comparison result between the amount of change in position and the threshold value; Including, the criteria for determining the contact include whether the amount of change in the position is equal to or less than the threshold value during the time interval; When the work content indicates work of compacting the object at a loading location, the threshold value is set based on the strength of the loading location. Contact determination method.

2. Calculating the amount of change in the position The contact determination method according to claim 1 , further comprising:

3. At least one of the movable parts is a first movable part connected to a main body of the work machine; a second movable part connected to the first movable part; and a third movable part connected to the second movable part, In the acquiring step, information regarding the rotational position of at least one of the movable parts is acquired. The contact determination method according to claim 1 or 2.

4. A contact detection method described in any one of claims 1 to 3, further comprising generating a target trajectory for at least one of the one or more movable parts, the target trajectory extending beyond the surface of the object as viewed from the at least one movable part.

5. a first acquisition means for acquiring information relating to the position of at least one of one or more movable parts provided in the work machine; a second acquisition means for acquiring information about the work content of the work machine and the object of work performed by the work machine; a setting means for setting a threshold value serving as a criterion for determining contact between the work machine and the object, for the amount of change in position of the movable part specified in accordance with the information regarding the position, and a time interval serving as a criterion for determining contact between the work machine and the object, in accordance with the work content and the object; a determination means for determining whether the work machine has come into contact with the object based on a result of comparing the amount of change in position with the threshold value; Equipped with the criteria for determining the contact include whether the amount of change in the position is equal to or less than the threshold value during the time interval; When the work content indicates work of compacting the object at a loading location, the setting means sets the threshold value based on the strength of the loading location. Contact detection system.

6. a calculation means for calculating the amount of change in the position The collision determination system according to claim 5 , further comprising:

7. At least one of the movable parts is a first movable part connected to a main body of the work machine; a second movable part connected to the first movable part; and a third movable part connected to the second movable part, The first acquisition means acquires information about the rotational position of at least one of the movable parts. The collision determination system according to claim 5 or 6.

8. A program for causing a computer to function as a contact determination device, the program causing the computer to function as: first acquisition means for acquiring information relating to the position of at least one of one or more movable parts equipped on a work machine; second acquisition means for acquiring information relating to the work content of the work machine and an object of work performed by the work machine; setting means for setting, in accordance with the work content and the object, a threshold value that serves as a reference for determining contact between the work machine and the object for the amount of change in position of the movable part specified in accordance with the information relating to the position, and a time interval that serves as a reference for determining contact between the work machine and the object; and determination means for determining contact between the work machine and the object based on the result of comparing the amount of change in position with the threshold value, the criteria for determining the contact include whether the amount of change in the position is equal to or less than the threshold value during the time interval; When the work content indicates work of compacting the object at a loading location, the setting means sets the threshold value based on the strength of the loading location. program.

9. The program further includes a program that causes the computer to function as a calculation means for calculating the amount of change in the position. The program according to claim 8.

10. At least one of the movable parts is a first movable part connected to a main body of the work machine; a second movable part connected to the first movable part; and a third movable part connected to the second movable part, The first acquisition means acquires information about the rotational position of at least one of the movable parts. The program according to claim 8 or 9.

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