Work machine and work machine control method

Abstract

To achieve both prevention of contact with an obstacle and prevention of instability due to braking.SOLUTION: The work machine restricts the operation of the traveling body, the revolving body, and the work implement by the operating device when the obstacle is detected while the operation amounts of the traveling body, the revolving body, and the work implement are less than a threshold. The work machine does not limit the operation of at least one of the traveling body and the revolving body when the obstacle is detected while the operation amount of at least one of the traveling body and the revolving body exceeds the threshold. The work machine restricts the operation of driving the work implement when the obstacle is detected while the operation amounts of the traveling body and the revolving body are less than the threshold value and the operation of driving the work implement is performed.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a work machine and a method for controlling a work machine. [Background technology]

[0002] Patent Document 1 discloses a technique for restricting the operation of a work machine in accordance with the detection results of an object present in the vicinity of the work machine. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7441699 Summary of the Invention [Problem to be solved by the invention]

[0004] When an obstacle such as a person or object is detected near a work machine, the operation of the work machine is restricted to avoid contact with the obstacle. However, sudden braking can cause the work machine to become unstable. Therefore, work machines are required to be able to both prevent contact with obstacles and prevent instability due to braking. An object of the present disclosure is to provide a work machine and a control method for a work machine that can simultaneously prevent contact with an obstacle and prevent instability due to braking. [Means for solving the problem]

[0005] According to one aspect of the present invention, a work machine is a work machine comprising a running body, a rotating body that can rotate relative to the running body, and a work machine, and is equipped with an operating device that accepts operation of the running body, the rotating body, and the work machine, an obstacle detection unit that detects obstacles present around the work machine, and a limiting unit that limits control of the work machine by the operating device based on the results of the obstacle detection, wherein the limiting unit limits operation of the running body, the rotating body, and the work machine by the operating device when the obstacle is detected while the operation amount of the running body, the rotating body, and the work machine is less than a threshold, does not limit operation of at least one of the running body and the rotating body when the obstacle is detected while the operation amount of at least one of the running body and the rotating body exceeds the threshold, and limits the operation to drive the work machine when the obstacle is detected while the operation amount of the running body and the rotating body is less than the threshold and an operation to drive the work machine is being performed. [Effects of the Invention]

[0006] According to the above aspect, the work machine can achieve both prevention of contact with an obstacle and prevention of instability due to braking. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a perspective view showing the appearance of a work machine according to a first embodiment. [Figure 2] 1 is a diagram showing the configuration of an operation device of a work machine according to a first embodiment. FIG. [Figure 3] 1 is a schematic block diagram showing the configuration of a drive system that drives a work machine according to a first embodiment and a control system that controls the drive system. [Figure 4] 4 is a flowchart showing the behavior of the work machine according to the first and second embodiments when a person is detected. [Figure 5] FIG. 10 is a perspective view showing the appearance of a work machine according to a second embodiment. [Figure 6] FIG. 10 is a schematic block diagram showing the configuration of a drive system that drives a work machine according to a second embodiment and a control system that controls the drive system. DETAILED DESCRIPTION OF THE INVENTION

[0008] First Embodiment <Configuration of work machine 10> Hereinafter, the embodiments will be described in detail with reference to the drawings. Fig. 1 is a perspective view showing the appearance of a work machine 10 according to a first embodiment. The work machine 10 shown in Fig. 1 is a small backhoe excavator (mini excavator). The work machine 10 includes a traveling body 110, a rotating body 120, a work implement 130, and a blade 140.

[0009] The traveling body 110 supports the work machine 10 so that the work machine 10 can travel. The traveling body 110 includes two crawlers 111 provided on the left and right, and a track frame 112 that supports the crawlers 111.

[0010] The rotating unit 120 is supported on the running unit 110 so as to be able to rotate about a rotation center. The rotating unit 120 has a floor frame 121, a driver's seat 122 arranged on the floor frame 121, a canopy 123 arranged above the driver's seat 122, and an operating device 124 for operating the work machine 10.

[0011] 2 is a diagram showing the configuration of the operating device 124 of the work machine 10 according to the first embodiment. The operating device 124 includes a left operating lever 124a, a right operating lever 124b, a left traveling lever 124c, a right traveling lever 124d, a swing pedal 124e, and a blade lever 124f. The left working lever 124a and the right working lever 124b are levers for operating the up / down, front / rear and rotation of the rotating body 120. The up / down, front / rear and rotation of the working machine 130 includes raising and lowering the boom 132, pushing and pulling the arm 133, and digging and dumping the bucket 134. The left travel lever 124c is a lever for driving the left crawler 111 forward and backward. The right travel lever 124d is a lever for driving the right crawler 111 forward and backward. The swing pedal 124e is a pedal for swinging the work machine 130. The blade lever 124f is a lever for driving the blade 140 up and down.

[0012] The work implement 130 is hydraulically driven and supported on the front part of the revolving body 120 so as to be drivable up and down and forward and backward.

[0013] The work implement 130 includes a swing bracket 131, a boom 132, an arm 133, and a bucket 134 as a work implement. Other examples of work implements include end attachments such as a clam bucket, tilt bucket, tilt rotator, grapple, and lifting magnet. In the work machine 10 shown in FIG. 1 , the work implement 130 is provided in front of the driver's seat 122.

[0014] The swing bracket 131 is rotatably attached to the front of the rotating body 120 via a swing pin that extends in the vertical direction. The base end of the boom 132 is rotatably attached to the swing bracket 131 via a boom pin extending in the vehicle width direction. The arm 133 connects the boom 132 and the bucket 134. The base end of the arm 133 is rotatably attached to the tip of the boom 132 via an arm pin that extends in the vehicle width direction. The bucket 134 is rotatably attached to the tip of the arm 133 via a bucket pin extending in the vehicle width direction. The bucket 134 functions as a container for storing excavated earth and sand.

[0015] The blade 140 is rotatably attached to the front of the vehicle 110 via a blade pin extending in the vehicle width direction.

[0016] Drive and control systems 3 is a schematic block diagram showing the configuration of a drive system 200 that drives the work machine 10 according to the first embodiment, and a control system 300 that controls the drive system 200. The drive system 200 includes an engine 201, a hydraulic oil pump 202, a control valve 203, a pilot pump 204, a lock solenoid 205, a pilot valve 206, a travel motor 207, a swing motor 208, a swing cylinder 209, a boom cylinder 210, an arm cylinder 211, a bucket cylinder 212, and a blade cylinder 213.

[0017] The engine 201 is a power source that drives the hydraulic oil pump 202 . The hydraulic oil pump 202 is a variable displacement pump driven by the engine 201. The hydraulic oil pump 202 supplies hydraulic oil to each actuator (right traveling motor 207R, left traveling motor 207L, swing motor 208, swing cylinder 209, boom cylinder 210, arm cylinder 211, bucket cylinder 212, and blade cylinder 213) via a control valve 203.

[0018] The control valve 203 controls the flow rate and direction of hydraulic oil supplied from the hydraulic oil pump 202. The control valve 203 has a spool inside, and the spool is operated by the hydraulic pressure of the pilot oil supplied from the pilot pump 204, thereby controlling the flow rate and direction of the hydraulic oil. Specifically, the control valve 203 has inlet ports corresponding to the forward movement of the right crawler 111, the retraction of the right crawler 111, the forward movement of the left crawler 111, the retraction of the left crawler 111, the right rotation of the rotating body 120, the left rotation of the rotating body 120, the raising of the boom 132, the lowering of the boom 132, the pushing of the arm 133, the pulling of the arm 133, the digging of the bucket 134, the dumping of the bucket 134, the raising of the blade 140, the lowering of the blade 140, the right swing of the swing bracket 131, and the left swing of the swing bracket 131, and hydraulic oil is supplied from each port to the corresponding actuator.

[0019] The pilot oil supplied to the control valve 203 is returned to the tank from an outlet port. The control valve 203 has a first outlet port that collects and discharges pilot oil that commands the right crawler 111 to move forward, the right crawler 111 to move backward, the left crawler 111 to move forward, and the left crawler 111 to move backward, a second outlet port that collects and discharges pilot oil that commands the right rotation of the rotating unit 120, the left rotation of the rotating unit 120, and the pulling of the arm 133, and a third outlet port that collects and discharges pilot oil that commands the raising of the boom 132, the lowering of the boom 132, the pushing of the arm 133, the digging of the bucket 134, the dumping of the bucket 134, the raising of the blade 140, the lowering of the blade 140, the right swing of the swing bracket 131, and the left swing of the swing bracket 131. Branch oil lines that connect the oil line connecting the control valve 203 and the pilot valve 206 to each outlet port are provided with check valves to prevent backflow of pilot oil.

[0020] The pilot pump 204 is a variable displacement pump driven by the engine 201. The pilot pump 204 supplies pilot oil to the control valve 203 via a pilot valve 206. The lock solenoid 205 is a solenoid valve provided in the pipe connecting the pilot pump 204 and the pilot valve 206. The lock solenoid 205 receives an input of a control signal and opens or closes the pipe connecting the pilot pump 204 and the pilot valve 206 in accordance with the control signal. In other words, the lock solenoid 205 can stop the supply of pilot oil upstream of the pilot valve 206. Pilot valve 206 controls the hydraulic pressure of pilot oil supplied from pilot pump 204 in response to operation of operating device 124. Pilot valve 206 branches the pilot oil in response to each of the following operations: advancing right crawler 111, retracting right crawler 111, advancing left crawler 111, retracting left crawler 111, right rotation of rotating body 120, left rotation of rotating body 120, raising boom 132, lowering boom 132, pushing arm 133, pulling arm 133, digging bucket 134, dumping bucket 134, raising blade 140, lowering blade 140, right swing of swing bracket 131, and left swing of swing bracket 131, and supplies the branched pilot oil to control valve 203.

[0021] The travel motor 207 is driven by hydraulic oil supplied from the hydraulic oil pump 202 via a control valve 203, and drives the crawler 111. The swing motor 208 is driven by hydraulic oil supplied from the hydraulic oil pump 202 via a control valve 203, and drives the rotating body 120 to rotate. The swing cylinder 209 is driven by hydraulic oil supplied from the hydraulic oil pump 202 via the control valve 203, and rotates the swing bracket 131 about an axis parallel to the rotation axis of the rotating body 120, thereby swinging the work implement 130 left and right. The boom cylinder 210 is driven by hydraulic oil supplied from the hydraulic oil pump 202 via the control valve 203, and drives the boom 132 up and down. The arm cylinder 211 is driven by hydraulic oil supplied from the hydraulic oil pump 202 via the control valve 203, and drives the arm 133 back and forth. The bucket cylinder 212 is driven by hydraulic oil supplied from the hydraulic oil pump 202 via a control valve 203 to drive the bucket 134 for dumping or excavation. The blade cylinder 213 is driven by hydraulic oil supplied from the hydraulic oil pump 202 via a control valve 203 to drive the blade 140 up and down.

[0022] The control system 300 includes a camera 301 , a human detection device 302 , a first hydraulic switch 303 , a second hydraulic switch 304 , a third hydraulic switch 305 , and a relay 306 . The cameras 301 are provided on the left, right, and rear of the revolving unit 120 and capture images of the surroundings of the work machine 10. The human detection device 302 detects people present around the work machine 10 from the image captured by the camera 301. Specifically, the human detection device 302 extracts people from the image and determines whether or not the person is present inside a predetermined distance from the work machine 10 based on the extracted position on the image. People present around the work machine 10 are an example of an obstacle, and the human detection device 302 is an example of an obstacle detection unit.

[0023] The first hydraulic switch 303 detects whether the hydraulic pressure of the pilot oil for controlling the left rotation of the rotating body 120 in the pipe connecting the pilot valve 206 and the control valve 203 exceeds a predetermined pressure threshold, and outputs a signal indicating the detection result to the relay 306. The pressure threshold is set to a pressure value (e.g., 1.5 MPa) at which the presence or absence of an operation can be detected. In other words, the first hydraulic switch 303 detects a valid left rotation operation. The second hydraulic switch 304 detects whether the hydraulic pressure of the pilot oil for controlling the right rotation of the rotating body 120 in the pipe connecting the pilot valve 206 and the control valve 203 exceeds a predetermined pressure threshold, and outputs a signal indicating the detection result to the relay 306. In other words, the second hydraulic switch 304 detects a valid operation for right rotation. The third hydraulic switch 305 detects whether the hydraulic pressure in the pipe connected to a first outlet port that collects and discharges pilot oil that commands the forward movement of the right crawler 111, the reverse movement of the right crawler 111, the forward movement of the left crawler 111, and the reverse movement of the left crawler 111 exceeds a predetermined pressure threshold, and outputs a signal indicative of the detection result to the relay 306. In other words, the third hydraulic switch 305 detects a valid operation for traveling.

[0024] Note that, although the work machine 10 according to the first embodiment is equipped with three hydraulic switches, this is not limited to this. For example, a work machine 10 according to another embodiment may have a collecting pipe with a check valve that joins a pipe through which pilot oil for controlling the left rotation of the rotating body 120 passes, and a pipe through which pilot oil for controlling the right rotation of the rotating body 120 passes, and thereby detect the presence or absence of a rotation operation using a single hydraulic switch instead of the first hydraulic switch 303 and the second hydraulic switch 304. Furthermore, a work machine 10 according to another embodiment may have a collecting pipe with a check valve that joins a pipe through which pilot oil for controlling the left rotation of the rotating body 120 passes, and a pipe through which pilot oil for controlling the right rotation of the rotating body 120 passes, and a first outlet port, and thereby detect the presence or absence of a rotation operation using a single hydraulic switch instead of the first hydraulic switch 303, the second hydraulic switch 304, and the third hydraulic switch 305. In other embodiments, instead of the third hydraulic switch 305, the work machine 10 may have a plurality of hydraulic switches 305 that detect pilot oil that respectively indicates the forward movement of the right crawler 111, the reverse movement of the right crawler 111, the forward movement of the left crawler 111, and the reverse movement of the left crawler 111.

[0025] The relay 306 switches the lock solenoid 205 on / off in accordance with the detection results of the human detection device 302, the first hydraulic switch 303, the second hydraulic switch 304, and the third hydraulic switch 305. Specifically, the relay 306 closes the lock solenoid 205 when a human being is detected within a predetermined distance from the work machine 10 and no valid operation for left turning, right turning, or traveling is detected. On the other hand, even if a human being is detected within the predetermined distance from the work machine 10, the relay 306 does not close the lock solenoid 205 when a valid operation for left turning, right turning, or traveling is detected. Furthermore, the relay 306 opens the lock solenoid 205 when a human being within the predetermined distance from the work machine 10 is no longer detected. For example, the relay 306 outputs to the lock solenoid 205 a signal related to the logical product of the negative OR of the detection signals of the first hydraulic switch 303, the second hydraulic switch 304, and the third hydraulic switch 305 and the detection signal from the human detection device 302. In other words, the relay 306 and the lock solenoid 205 are an example of a limiting section that limits the control of the work machine 10 by the operating device 124 based on the result of detecting an obstacle.

[0026] <<Explanation of operation>> 4 is a flowchart showing the behavior of the work machine 10 according to the first and second embodiments when a person is detected. The person detection device 302 executes a process to detect a person around the work machine 10 based on the image captured by the camera 301, and outputs a signal indicating the person detection result to the relay 306 (step S1). Furthermore, the first hydraulic switch 303, the second hydraulic switch 304, and the third hydraulic switch 305 detect the presence or absence of pilot oil flow related to left turning, right turning, and traveling, respectively, and output a signal indicating the pilot oil detection result to the relay 306 (step S2). Note that the work machine 10 according to the first embodiment does not detect the presence or absence of pilot oil flow related to the operation of the work implement 130.

[0027] If the work machine 10 is not operating (step S3: NO) and the signal output from the human detection device 302 indicates that no human has been detected (step S4: NO), the signal output from the relay 306 is False, and the lock solenoid 205 is open. Therefore, the work machine 10 does not restrict the operation of the traveling body 110, the revolving body 120, and the work implement 130 (step S5). On the other hand, if the work machine 10 is not operating (step S3: NO) and the signal output from the human detection device 302 indicates that a human has been detected (step S4: YES), the signal output from the relay 306 is True, and the lock solenoid 205 is closed. In this case, the work machine 10 restricts the operation of the traveling body 110, the revolving body 120, and the work implement 130 (step S6).

[0028] When the work machine 10 is operating (step S3: YES) and the signal output from the human detection device 302 indicates that no human has been detected (step S7: NO), the signal output from the relay 306 is False, and the lock solenoid 205 is open. Therefore, the work machine 10 does not restrict the operation of the traveling body 110, the revolving body 120, and the work implement 130 (step S8). When the work machine 10 is operating (step S3: YES) and the signal output from the human detection device 302 indicates that a human has been detected (step S7: YES), and only the work implement is operating (step S9: YES), the signal output from the relay 306 is True, and the lock solenoid 205 is closed. Therefore, the work machine 10 restricts the operation of the traveling body 110, the revolving body 120, and the work implement 130 (step S10).

[0029] When the work machine 10 is operating (step S3: YES) and the signal output from the human detection device 302 indicates that a person has been detected (step S7: YES), and at least the running body 110 or the revolving body 120 is operating (step S9: NO), the signal output from the relay 306 is False, and the lock solenoid 205 is open. Therefore, the work machine 10 does not restrict the operation of the running body 110, the revolving body 120, and the work implement 130 (step S8).

[0030] Here, the operation of the work machine 10 will be explained using several scenarios. First, the operation of the work machine 10 in a scene (scene 1) in which a person approaches the work machine 10 while the work machine 10 is not being operated will be described. In scene 1, because the work machine 10 is not being operated, pilot oil does not flow from the pilot valve 206 to the control valve 203. Therefore, the first hydraulic switch 303, the second hydraulic switch 304, and the third hydraulic switch 305 all output detection signals indicating that the hydraulic pressure does not exceed a predetermined pressure (False). Furthermore, because a person has approached the work machine 10, the human detection device 302 outputs a detection signal indicating that a person has been detected within a predetermined distance (True). The NOR of the detection signals from the three hydraulic switches is True, and the detection signal from the human detection device 302 is True, so the logical product of these is True. Therefore, the lock solenoid 205 is closed by a signal from the relay 306, and pilot oil is no longer supplied to the pilot valve 206. As a result, in scene 1, the work machine 10 does not drive regardless of whether the operating device 124 is operated or not. This makes it possible to prevent contact with nearby people due to unexpected operation of the work machine 10.

[0031] Next, the operation of the work machine 10 in a situation (second situation) in which a person approaches the work machine 10 while the revolving unit 120 is being operated to swing left will be described. In the second situation, the revolving unit 120 is being operated to swing left, so the first hydraulic switch 303 outputs a detection signal indicating that the hydraulic pressure exceeds a predetermined pressure (True). As a result, the NOR of the detection signals from the three hydraulic switches is False. Therefore, the NOR of the detection signals from the three hydraulic switches and the detection signal from the person detection device 302 is False. Therefore, the relay 306 maintains the lock solenoid 205 in an open state. As a result, in the second situation, the work machine 10 continues to swing left, and the revolving unit 120 does not stop suddenly. This makes it possible to prevent instability in the work machine 10 caused by a sudden stop of the revolving unit 120. In the case of a mini excavator such as that shown in FIG. 1, it is not uncommon for workers to work in the vicinity of the work machine 10 while it is in operation, and so long as the operator and the workers are paying sufficient attention, it is safer to continue operating the work machine 10 than to make an emergency stop which could cause instability.

[0032] Next, the operation of the work machine 10 in a situation (third situation) in which a person approaches the work machine 10 while the traveling object 110 is traveling will be described. In the third situation, the traveling object 110 is being operated to travel, so the third hydraulic switch 305 outputs a detection signal indicating that the hydraulic pressure exceeds a predetermined pressure (True). As a result, the NOR of the detection signals from the three hydraulic switches is False. Therefore, the NOR of the detection signals from the three hydraulic switches and the detection signal from the human detection device 302 is False. Therefore, the relay 306 maintains the lock solenoid 205 in an open state. As a result, in the second situation, the traveling object 110 continues to travel and does not suddenly stop. This makes it possible to prevent instability in the work machine 10 caused by a sudden stop of the traveling object 110.

[0033] Next, the operation of the work machine 10 in a situation (fourth situation) in which a person approaches the work machine 10 while the work machine 130 is operating without swinging or traveling will be described. In the fourth situation, the work machine 130 is being operated, but the swing unit 120 and the traveling unit 110 are not, so the NOR of the detection signals from the three hydraulic switches is True. Therefore, the NOR of the detection signals from the three hydraulic switches and the detection signal from the human detection device 302 is True. This causes the relay 306 to close the lock solenoid 205. That is, in the fourth situation, when the human detection device 302 detects a person, the drive of the work machine 130 is stopped. Therefore, the work machine 10 can prevent the work machine 130 from coming into contact with a nearby person due to the work machine 130 being stopped. The inertial system related to the swing and travel includes the swing unit 120 and the work implement 130, whereas the inertial system related to the drive of the work implement 130 does not include the swing unit 120. Furthermore, the weight of the work implement 130 is lighter than the weight of the swing unit 120. Therefore, the inertial force generated when the work implement 130 is suddenly stopped is smaller than the inertial force generated when the swing and travel are suddenly stopped. Therefore, stopping the work implement 130 is unlikely to cause instability in the work machine 10.

[0034] Next, the operation of the work machine 10 in a situation (fifth situation) in which a person approaches the work machine 10 while the work implement 130 is being driven while the revolving unit 120 is being operated to rotate right will be described. In the fifth situation, the revolving unit 120 is being operated to rotate right, so the second hydraulic switch 304 outputs a detection signal indicating that the hydraulic pressure exceeds a predetermined pressure (True). As a result, the NOR of the detection signals from the three hydraulic switches is False. Therefore, the NOR of the detection signals from the three hydraulic switches and the logical product of the detection signal from the human detection device 302 is False. Therefore, the relay 306 maintains the lock solenoid 205 in an open state. As a result, in the fifth situation, the work machine 10 continues to rotate left and the work implement 130 continues to be driven, and the revolving unit 120 and the work implement 130 do not suddenly stop. By continuing to rotate the revolving unit 120, it is possible to prevent instability in the work machine 10 caused by a sudden stop of the revolving unit 120. Here, the reason why the work machine 10 allows the driving of not only the rotating unit 120 but also the work implement 130 will be explained. When there is a person near the work machine 10, the operator of the work machine 10 may intend to rotate the rotating unit 120 while raising the boom 132 or pulling the arm 133, thereby preventing the work implement 130 from coming into contact with the person. In such a situation, if the work machine 10 stops only the driving of the work implement 130, the rotating unit 120 may rotate without raising the boom 132 or pulling the arm 133, which could result in contact between the work implement 130 and the person. Therefore, in the fifth situation in which a person approaches the work machine 10 while the rotating unit 120 is operating to turn right and the work implement 130 is driving, the possibility of the work implement 130 coming into contact with the person can be reduced by maintaining not only the rotation but also the driving of the work implement 130.

[0035] In addition, in the second, third, and fifth scenes, if the travel and swing operations are subsequently ended while there is a person near the work machine 10, the NOR of the detection signals from the three hydraulic switches becomes True. As a result, the lock solenoid 205 is closed by a signal from relay 306, and pilot oil is no longer supplied to the pilot valve 206. In other words, in the second, third, and fifth scenes, driving of the work machine 10 is permitted only while the work machine 10 continues to be driven, and once the swing or travel operation of the work machine 10 stops, the drive of the work machine 10 is locked thereafter. This makes it possible to prevent contact with nearby people due to unexpected operation of the work machine 10.

[0036] Next, the operation of the work machine 10 in a situation (sixth situation) in which there is no longer a person near the work machine 10 while the lock solenoid 205 has stopped the supply of pilot oil will be described. In the sixth situation, because the supply of pilot oil is stopped by the lock solenoid 205, all hydraulic switches output detection signals indicating that the hydraulic pressure does not exceed a predetermined pressure (False), regardless of whether the operation device 124 is operated. On the other hand, when there is no longer a person near the work machine 10, the human detection device 302 outputs a detection signal indicating that no person has been detected within a predetermined distance (False). The NOR of the detection signals from the three hydraulic switches is True, and the detection signal from the human detection device 302 is False, so the logical product of these is False. Therefore, the signal from the relay 306 opens the lock solenoid 205, and pilot oil begins to be supplied to the pilot valve 206. In other words, when there is no longer a person near the work machine 10, the restriction on operation of the traveling unit 110, the revolving unit 120, and the work implement 130 by the operation device 124 is released.

[0037] In this way, the work machine 10 according to the first embodiment restricts the operation of the running body 110, the rotating body 120, and the work implement 130 by the operation device 124 when an obstacle (person) is detected while no operation is being performed to drive the running body 110, the rotating body 120, and the work implement 130. Furthermore, the work machine 10 does not restrict the operation of the running body 110 and the rotating body 120 when an obstacle is detected while an operation is being performed to drive at least one of the running body 110 and the rotating body 120. The work machine 10 restricts the operation of driving the work implement 130 up, down, forward, or backward when an obstacle is detected while no operation is being performed to drive the running body 110 and the rotating body 120 and an operation is being performed to drive the work implement 130 up, down, forward, or backward. This allows the work machine 10 to both prevent contact with an obstacle and prevent instability due to braking.

[0038] Note that the work machine 10 according to the first embodiment stops the drive of the work implement 130 if a person is detected when only the work implement 130 is being driven. In other words, the work machine 10 according to the first embodiment also stops the drive of the work implement 130 if a person is detected when an operation to drive the swing cylinder 209 or the blade 140 is being performed. On the other hand, this is not limited to this. For example, the work machine 10 according to other embodiments may maintain the operation of the swing cylinder 209 and the blade 140 even if a person is detected when an operation to drive the swing cylinder 209 or the blade 140 is being performed. Note that the swing operation is an operation to drive the work implement 130 left and right, and is not an operation to drive the work implement 130 up and down, or forward and backward.

[0039] Second Embodiment The work machine 10 according to the first embodiment has a swing cylinder 209 and is configured to be able to swing the work implement 130 in the left-right direction. In contrast, the work machine 10 according to the second embodiment has an offset mechanism that moves the work implement 130 parallel to the vehicle width direction. 5 is a perspective view showing the appearance of a work machine 10 according to the second embodiment. The work implement 130 according to the second embodiment does not include a swing bracket 131. The boom 132 of the work implement 130 according to the second embodiment includes a first boom 132A, a second boom 132B, a boom bracket 132C, and a link rod 132D.

[0040] The base end of the first boom 132A is mounted to the revolving unit 120 via a boom pin so as to be rotatable in the vertical direction. The base end of the second boom 132B is connected to the tip of the first boom 132A via a first offset pin extending in the vertical direction of the boom 132. The second boom 132B is mounted so as to be rotatable in the left-right direction relative to the first boom 132A around the first offset pin. The boom bracket 132C is connected to the tip of the second boom 132B via a second offset pin extending in the vertical direction of the boom 132. The boom bracket 132C is mounted so as to be rotatable in the left-right direction relative to the second boom 132B around the second offset pin.

[0041] The tip of the first boom 132A and the boom bracket 132C are connected by a link rod 132D. By providing the link rod 132D, the directions in which the first boom 132A and the boom bracket 132C face always match, even if the second boom 132B tilts left or right.

[0042] FIG. 6 is a schematic block diagram showing the configuration of a drive system 200 that drives a work machine according to the second embodiment and a control system 300 that controls the drive system. The drive system 200 of the work machine 10 according to the second embodiment is equipped with an offset cylinder 214 instead of the swing cylinder 209. The offset cylinder 214 rotates the second boom 132B relative to the first boom 132A.

[0043] The behavior of the control system 300 in the work machine 10 according to the second embodiment is similar to that in the first embodiment. Therefore, the work machine 10 according to the second embodiment can prevent contact with obstacles and prevent instability due to braking, just like the first embodiment, even when the work implement 130 has an offset mechanism.

[0044] Note that the work machine 10 according to the second embodiment stops the drive of the work implement 130 if a person is detected when only the work implement 130 is being driven. In other words, the work machine 10 according to the second embodiment also stops the drive of the work implement 130 if a person is detected when an operation to drive the offset cylinder 214 is being performed. On the other hand, this is not limited to this. For example, the work machine 10 according to other embodiments may maintain the operation of the offset cylinder 214 and the blade 140 even if a person is detected when an operation to drive the offset cylinder 214 or the blade 140 is being performed. Note that the offset operation is an operation to drive the work implement 130 left and right, and is not an operation to drive the work implement 130 up and down, or forward and backward.

[0045] Other Embodiments Although one embodiment has been described in detail above with reference to the drawings, the specific configuration is not limited to the above, and various design modifications are possible. That is, in other embodiments, the order of the above-described processes may be changed as appropriate. Furthermore, some processes may be executed in parallel. The control system 300 according to the embodiment described above controls whether or not to stop the supply of pilot oil using the relay 306, but this is not limited to this. For example, in a work machine 10 according to another embodiment, a limiting unit that limits the drive of the work machine 10 may be implemented in a computer. In this case, the pilot oil may be controlled as a result of calculation based on signals from the human detection device 302 and each hydraulic switch.

[0046] Furthermore, although the work machine 10 according to the embodiment described above restricts the drive of the work machine 10 based on the detection results of people in the vicinity of the work machine 10, this is not limited to this. For example, a work machine 10 according to another embodiment may restrict the drive of the work machine 10 based on the detection results of obstacles other than people (vehicles, rocks, etc.).

[0047] Furthermore, while the work machine 10 according to the embodiment described above uses the pressure switches 303-305 to detect whether or not the work machine 10 is operating to travel or swing, this is not limiting. For example, the work machine 10 according to other embodiments may detect whether or not the work machine 10 is operating to travel or swing using a flow meter that measures the flow rate of pilot oil, a pressure gauge that measures the internal pressure of an oil line, or the like, instead of a pressure switch. Furthermore, a controller (not shown) provided in the control system 300 may detect whether or not the work machine 130 is operating to travel or swing from the angles of the various levers of the operating device 124 or the amount of depression of the pedal. In this case, the controller can measure the amount of operation for traveling and swing. In this case, the controller may limit the drive of the work machine 130 so that the work machine 130 gradually decelerates rather than suddenly stopping its drive, by changing the opening of the lock solenoid 205 according to the amount of operation.

[0048] Furthermore, while the work machine 10 according to the embodiment described above controls the control valve 203 using pilot oil, this is not limiting. For example, the control valve 203 according to other embodiments may be an electromagnetic control valve. In this case, the operating device 124 outputs the operation amount to the control valve 203 as an electric signal, and the control valve 203 determines the flow rate of hydraulic oil in accordance with the electric signal. In this case, the computer (control device) of the control system 300 determines whether or not to drive the work machine 10 based on the operation amount related to swinging or traveling obtained by reading the electric signal output from the operating device 124. In other words, the control device may determine whether or not to output the electric signal supplied from the operating device 124 to the control valve 203 based on the result of human detection and the operating state. In this case, the control device may limit the drive of the work machine 130 so that the drive of the work machine 130 is gradually decelerated rather than being suddenly stopped by rewriting the electric signal output from the operating device 124, rather than blocking it.

[0049] Furthermore, the work machine 10 according to the embodiment described above continues the operation of the running body 110 and the rotating body 120 even if a person is detected when an operation to drive at least one of the running body 110 and the rotating body 120 is being performed, but this is not limited to this. For example, a work machine 10 according to another embodiment may limit the operation of the running body 110 and the rotating body 120 when a person is detected while the running body 110 or the rotating body 120 is being driven, if the amount of operation is sufficiently small or the speed is sufficiently low. This is because, when the running body 110 and the rotating body 120 are traveling at low speeds, there is little chance that instability will occur due to braking. In this case, the pressure threshold value of the hydraulic switch may be set to a value higher than the pressure value at which the presence or absence of operation in the above-described embodiment can be detected.

[0050] The control device of the control system 300 includes a processor, memory, auxiliary storage device, etc., which are connected via a bus, and executes programs to realize the above-mentioned functions. Examples of the processor include a CPU (Central Processing Unit), a GPU (Graphic Processing Unit), and a microprocessor. The program may be recorded on a computer-readable recording medium, such as a storage device including a magnetic disk, a magneto-optical disk, an optical disk, or a semiconductor memory. The program may be transmitted via a telecommunications line. All or part of the control system 300 may be realized using a custom LSI (Large Scale Integrated Circuit), such as an ASIC (Application Specific Integrated Circuit) or a PLD (Programmable Logic Device). Examples of PLDs include PAL (Programmable Array Logic), GAL (Generic Array Logic), CPLD (Complex Programmable Logic Device), and FPGA (Field Programmable Gate Array). Such integrated circuits are also included in the scope of the processor. [Explanation of symbols]

[0051] 10...Work machine 110...Traveling body 111...Crawler 112...Track frame 120...Swinging body 121...Floor frame 122...Driver's seat 123...Canopy 124...Operating device 124a...Left working lever 124b...Right working lever 124c...Left traveling lever 124d...Right traveling lever 124e...Swing pedal 124f...Blade lever 130...Work machine 131...Swing bracket 132...Boom 132A...First boom 132B...Second boom 132C...Boom bracket 132D...Link rod 133...Arm 134...Bucket 140...Blade 200...Drive system 201...Engine 202...Hydraulic oil pump 203...Control valve 204...Pilot pump 205...Lock solenoid 206...Pilot valve 207...Travel motor 208... Swing motor 209... Swing cylinder 210... Boom cylinder 211... Arm cylinder 212... Bucket cylinder 213... Blade cylinder 214... Offset cylinder 300... Control system 301... Camera 302... Person detection device 303... First hydraulic switch 304... Second hydraulic switch 305... Third hydraulic switch 306... Relay

Claims

1. A work machine comprising a running body, a rotating body that can rotate relative to the running body, and a work implement, an operation device that accepts operations of the traveling body, the rotating body, and the work machine; an obstacle detection unit that detects obstacles present around the work machine; a limiting unit that limits control of the work machine by the operation device based on the result of the obstacle detection; Equipped with The limiting portion is when the obstacle is detected while the operation amount of the traveling body, the revolving body, and the work machine is less than a threshold, restricting the operation of the traveling body, the revolving body, and the work machine by the operation device; When the obstacle is detected while the operation amount of at least one of the traveling body and the rotating body exceeds a threshold, the operation of at least one of the traveling body and the rotating body is not restricted, When the obstacle is detected while the operation amount of the traveling body and the rotating body is less than a threshold value and an operation to drive the work machine is being performed, the operation to drive the work machine is limited. Work machinery.

2. a pilot valve that controls the flow rate of pilot oil in accordance with the operation amount of the operating device; a control valve that controls the amount of hydraulic oil supplied to the traveling body, the rotating body, and the work machine in accordance with the hydraulic pressure of the pilot oil; Equipped with The limiting portion is determining whether or not an operation amount of the traveling body, the rotating body, and the work machine exceeds a threshold value based on the hydraulic pressure of the pilot oil; By stopping the supply of the pilot oil upstream of the pilot valve, the operation of the traveling body, the rotating body, and the work machine by the operation device is restricted.

2. The work machine according to claim 1.

3. When the obstacle detection unit no longer detects an obstacle present around the work machine, the restriction on the operation of the traveling body, the rotating body, and the work machine by the operation device is released.

2. The work machine according to claim 1.

4. The work machine includes a boom, an arm, and a bucket.

2. The work machine according to claim 1.

5. the work machine includes at least one of a swing cylinder that rotates the boom around an axis parallel to the rotation axis of the rotating body or an offset cylinder that translates the boom in the vehicle width direction, When the obstacle is detected while the operation amount of the swing cylinder or the offset cylinder exceeds a threshold, the operation of driving the work machine is limited.

5. The work machine according to claim 4.

6. The limiting portion is When the obstacle is detected while the operation amount of at least one of the traveling body and the rotating body exceeds a threshold, the operation of driving the work machine is not restricted.

2. The work machine according to claim 1.

7. A control method for a work machine including a traveling body, a rotating body that can rotate relative to the traveling body, a work implement, and an operation device that accepts operations of the traveling body, the rotating body, and the work implement, A step in which a work machine detects an obstacle present around the work machine; a step of limiting operation of the traveling body, the rotating body, and the work machine by the operation device when the obstacle is detected while the operation amount of the traveling body, the rotating body, and the work machine does not exceed a threshold; a step of limiting an operation to drive the work machine when the obstacle is detected while no operation to drive the traveling body and the rotating body is being performed and the operation amount of the work machine exceeds a threshold; Equipped with When the obstacle is detected while the operation amount of at least one of the traveling body and the rotating body exceeds a threshold, the work machine does not restrict the operation of at least one of the traveling body and the rotating body. A method for controlling a work machine.

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