Work machine

Abstract

To provide a work machine capable of notifying an operator at an earlier stage of the risk of a work machine tipping over during remote operation.SOLUTION: A work machine 1 comprises a dynamic center-of-gravity position estimation unit 41 that estimates ZMP of the work machine, a support range calculation unit 40 that calculates a support range L of a vehicle body, an operator position determination unit 42 that determines positions P1 to P8 of the operator relative to the vehicle body from acquired position information, a determination range setting unit 431 that sets a high stability range L1 inside the support range L, a determination range correction unit 430 that generates a corrected high stability range L11 based on the positions P1 to P8, a vehicle body stability calculation unit 43 that determines that stability is high if the ZMP is within a corrected high stability range L11 and determines that stability is low if the ZMP is not within the corrected high stability range L11, and a buzzer 33 that outputs determination information from the vehicle body stability calculation unit 43.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] An example of a work machine is a hydraulic excavator. A hydraulic excavator has a lower traveling body, and an upper rotating body is attached to the upper part of the lower traveling body via a rotating device. A work device for performing work such as excavating earth and sand is attached to the upper rotating body. The work device includes a boom connected to the upper rotating body so as to be able to move up and down, and an arm connected to the tip of the boom so as to be able to rotate up and down. A bucket is attached to the tip of the arm as an attachment for performing work such as excavation, and is connected via a link mechanism.

[0003] Work machines such as hydraulic excavators must operate with high vehicle stability to prevent the vehicle body from tipping over during work. Vehicle stability is an index that indicates how unlikely the vehicle body is to tip over, and Patent Document 1, for example, discloses a work machine that can determine vehicle stability. The control cabin of the work machine is equipped with an information output device that notifies the operator on board of the determination result.

[0004] In addition to work machines operated by an operator who rides on them, it is also common for work machines to be equipped with a wireless communication receiver and operated by an operator with a corresponding transmitter from a position where the work machine can be seen. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6877385 Summary of the Invention [Problem to be solved by the invention]

[0006] Incidentally, when an operator operates a work machine remotely using a transmitter without being on board, the operator must visually check the inclination of the work machine and the condition of the road surface to estimate the stability of the work machine's body. With remote operation, the operator cannot physically feel the inclination of the work machine as he or she can when operating from on board, so it is more difficult to operate the work machine while preventing it from tipping over than when operating from on board. In particular, areas that are shaded by the work machine from the operator's perspective are blind spots, making it difficult to operate the work machine while preventing it from tipping over if it tips in the direction of the blind spot. An object of the present invention is to provide a work machine that prevents the work machine from tilting in a blind spot and tipping over when the work machine is remotely operated while being visually monitored from a nearby location without being on board. [Means for solving the problem]

[0007] A working machine according to an aspect of the present invention comprises a vehicle body, a work implement attached to the vehicle body, a posture information acquisition device that acquires posture information of the vehicle body and the work implement, and a control device that controls the vehicle body and the work implement based on the posture information acquired by the posture information acquisition device, and further comprises an operator position information acquisition device that acquires position information of an operator who remotely operates the vehicle body, and the control device comprises a dynamic center of gravity position estimation unit that estimates the dynamic center of gravity position of the working machine based on the posture information, a support range calculation unit that calculates a support range made up of ground contact points of the vehicle body based on dimensional information of the vehicle body, an operator position determination unit that determines the relative position of the operator with respect to the vehicle body from the position information acquired by the operator position information acquisition device, and a dynamic center of gravity position calculation unit that calculate ... the dynamic center of gravity position of the working machine based on dimensional information of the vehicle body, an operator position determination unit that determines the dynamic center of gravity position of the working machine based on the posture information acquired by the operator position information acquisition device, and a dynamic center of gravity position calculation unit that calculates the dynamic center of gravity position of the working machine based on the posture information, a dynamic center of gravity position calculation unit that calculates the dynamic center of gravity position of the working machine based on dimensional information of the vehicle body, an operator position determination unit that determines the dynamic center of gravity position of the working machine based on the posture information acquired by the operator position information acquisition device, and a dynamic center of gravity position calculation unit that calculates the dynamic center of gravity position of the working machine based on the posture information, a dynamic center of gravity position calculation unit that calculates the dynamic center of gravity position of the working machine based on the posture The vehicle stability control system includes a judgment range setting unit that sets a stability judgment range on the inside, a judgment range correction unit that corrects the stability judgment range to generate a narrower corrected stability judgment range based on the position of the operator calculated by the operator position judgment unit, a vehicle body stability calculation unit that judges that the stability of the vehicle body is high if the dynamic center of gravity position is within the corrected stability judgment range and judges that the stability of the vehicle body is low if the dynamic center of gravity position is not within the corrected stability judgment range, and an information output device that outputs judgment information from the vehicle body stability calculation unit, wherein the judgment range correction unit corrects the stability judgment range so that the range on the opposite side of the operator position across the vehicle body is narrower, and the information output device outputs the judgment information when the vehicle body stability calculation unit judges that the stability of the vehicle body is low. [Effects of the Invention]

[0008] According to the present invention, it is possible to notify the operator at an earlier stage of the risk of the work machine tipping over during remote operation, and to prevent the work machine from tipping over. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram showing the appearance of a hydraulic excavator. [Figure 2] 1 is a block diagram showing a system configuration according to an embodiment of the present invention; [Figure 3] FIG. 2 is a diagram illustrating the arrangement of each receiving antenna and their reception ranges. [Figure 4] FIG. 10 is a diagram illustrating a highly stable range. [Figure 5] FIG. 10 is a diagram illustrating an example of a post-correction high stability range. [Figure 6] FIG. 10 is a diagram illustrating another example of a post-correction high stability range. [Figure 7] FIG. 10 is a diagram illustrating an example of a post-correction high stability range in a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The following description and drawings are examples for explaining the present invention, and appropriate omissions and simplifications have been made for clarity of explanation. Furthermore, in the following description, identical or similar elements and processes are given the same reference numerals, and duplicate explanations may be omitted. Note that the content described below merely shows an example of an embodiment of the present invention, and the present invention is not limited to the following embodiment, and can be implemented in various other forms.

[0011] FIG. 1 is a diagram showing the appearance of a work machine 1. In this embodiment, a hydraulic excavator will be used as an example of the work machine 1. The work machine 1 comprises a lower traveling body 2, an upper rotating body 3, and a front work implement 4. The upper rotating body 3 is rotatably mounted on the lower traveling body 2, and together with the lower traveling body 2, constitutes a vehicle body 18. The front work implement 4 is rotatably mounted relative to the upper rotating body 3. A cab 17 is provided in front of the upper rotating body 3. Inside the cab 17, there is provided a driver's seat where an operator sits, and a work operation device made up of work operation levers for operating the work machine 1, etc. In FIG. 1, the left-right direction in the figure corresponds to the fore-and-aft direction of the vehicle body 18, and the direction perpendicular to the plane of the page corresponds to the left-right direction of the vehicle body 18.

[0012] The front working implement 4 includes a boom 5, an arm 6, and a bucket 7. The boom 5 is rotatably mounted on the upper rotating body 3 and is driven by a boom cylinder 8. The arm 6 is rotatably mounted at the tip of the boom 5 and is driven by an arm cylinder 9. The bucket 7, rotatably mounted at the tip of the arm, is driven by a bucket cylinder 10. The bucket cylinder 10 is connected to the arm 6 by a link 11 and to the bucket 7 by a link 12.

[0013] The upper rotating body 3, boom 5, arm 6, and link 11 are respectively equipped with a vehicle body IMU 13, a boom IMU 14, an arm IMU 15, and a bucket IMU 16. IMU is an abbreviation for Inertial Measurement Unit, and can detect three-axial angles (or angular velocities) and accelerations. That is, the vehicle body IMU 13 can acquire the rotation direction and rotation angular velocity of the upper rotating body 3, as well as the tilt angles of the upper rotating body 3 in the front-to-back and left-to-right directions. In addition, the IMUs 14, 15, and 16 can acquire the rotation angles and angular velocities of the boom 5, arm 6, and bucket 7, respectively. In this way, the vehicle body IMU 13, the boom IMU 14, the arm IMU 15, and the bucket IMU 16 function as a posture information acquisition device 31 that acquires posture information of the upper rotating body 3 and the boom 5, arm 6, and bucket 7 that constitute the front work implement 4.

[0014] Figure 2 is a block diagram showing the system configuration of this embodiment. The controller 30 mounted on the work machine 1 has a microcomputer consisting of a CPU, ROM, RAM, and rewritable non-volatile memory such as flash memory (not shown), as well as computer programs and peripheral circuits stored in the ROM. The controller 30 functions as a support range calculation unit 40, a dynamic center of gravity position estimator 41, an operator position determiner 42, and a vehicle body stability calculation unit 43 by running a computer program on the CPU to perform calculation processing. Memory 44 pre-stores dimensional information of the vehicle body 18 used by the support range calculation unit 40, threshold information used by the vehicle body stability calculation unit 43, and the like. A buzzer 33 is provided inside the cab 17 and the vehicle body 18 of the work machine 1 to sound an alarm to the operator operating the cab and nearby workers, etc.

[0015] The work machine 1 is configured to be able to be operated using an indoor operation device 171 inside the cab 17 (on-board operation), and also to be able to be operated without being on-board (remote operation) using a remote control operation device 35, which is a remote operation device, in a state where the work machine 1 can be seen from outside the cab 17. A switching operation unit 172 is provided in the cab 17 for switching between on-board operation and remote operation. In the example shown in FIG. 2 , the mode has been switched to remote operation, and the operator remotely operates the work machine 1 using the remote control operation device 35. Signals are exchanged between the remote control operation device 35 and the work machine 1 by a communication device 34. The operator operating the remote control operation device 35 wears an RFID (Radio Frequency Identification) tag 110. Work information of the work machine 1 is transmitted via the communication device 34 to a management office 100 located away from the work site. A receiving device is provided in the management office 100, and the work information of the work machine 1 is presented to staff at the management office 100 via the receiving device.

[0016] The operator position acquisition device 32 is equipped with receiving antennas 32a, 32b, 32c, and 32d attached to the front, left, right, and rear of the vehicle body 18 (for example, the upper rotating body 3), and receives signals from an RFID (Radio Frequency Identification) tag 110 worn by the operator. FIG. 3 is a diagram illustrating the arrangement of the receiving antennas 32a, 32b, 32c, and 32d and their reception ranges A1 to A4. FIG. 3 is a plan view of the work machine 1 as seen from above, with the reception ranges A1 to A4 superimposed. In FIG. 3, the X-axis represents the fore-and-aft direction of the vehicle body 18 of the work machine 1, with the positive direction being the forward direction. Similarly, the Y-axis represents the left-right direction of the vehicle body 18, with the positive direction being the right direction.

[0017] The support range calculation unit 40 calculates the support range L of the work machine 1 as shown in FIG. 4 using dimensional information of the undercarriage 2 that is pre-stored in the memory 44 of the controller 30. In FIG. 4, the X-axis and Y-axis are set in the same way as in FIG. 3. The support range L is a convex range formed by the contact points between the undercarriage 2 and the ground surface when the work machine 1 is standing upright on flat ground as shown in FIG. 1. Therefore, when the contact points between the undercarriage 2 and the ground surface form part of a rectangle, the support range L becomes a rectangular range (X1≦X≦X2 and Y1≦Y≦Y2) as shown in FIG. 4. In the case of a work machine whose body is bendable, such as a wheel loader, the shape of the support range L changes depending on the bending state (see, for example, JP 2023-149733 A).

[0018] The dynamic center-of-gravity position estimating unit 41 estimates the dynamic center-of-gravity position of the work machine 1. The dynamic center-of-gravity position is a center-of-gravity position that takes into account the influence of inertial forces that occur when the lower traveling body 2 travels or when the front working implement 4 or upper rotating body 3 operates, relative to the static center-of-gravity position of the work machine 1. For example, in the technology described in Japanese Patent No. 6877385, ZMP (Zero Moment Point) is used as an index that represents the dynamic center-of-gravity position. An example in which the ZMP is used as the dynamic center-of-gravity position will be described below.

[0019] The ZMP is calculated as the point where the extension of the resultant vector of gravity, centrifugal force, and inertial force acting on the center of gravity intersects with the ground. When the work machine 1 is stopped and only gravity is acting, the ZMP coincides with the projection of the static center of gravity onto the ground surface. Therefore, the ZMP can be treated as the projection of the center of gravity taking into account both dynamic and static states, and by using the ZMP as an index, it is possible to handle both cases where the object is stationary and when it is moving in a unified manner.

[0020] Gravity, inertial force, external force, and their moments act from the work machine 1 to the ground surface, but according to D'Alembert's principle, these are balanced by the ground reaction force and ground reaction force moment that act as reactions from the ground surface to the work machine 1. Stability determination using the ZMP is a determination method based on D'Alembert's principle that uses the ZMP as an evaluation index for determining the stability of a structure (work machine 1). If the ZMP is located inside the support range L (see Figure 4) of the work machine 1, it can be said that the work machine 1 is stably in contact with the ground surface. The closer the ZMP is to the center of the support range L, the higher the stability, and if the ZMP is inside the support range L, the work machine 1 can perform work without lifting up. On the other hand, if the ZMP is located outside the support range L, there is a possibility that the work machine 1 will lift up. Therefore, by using the ZMP as the dynamic center of gravity position, the stability of the work machine 1 can be determined by comparing the ZMP with the support range L formed at the contact point between the work machine 1 and the ground surface.

[0021] 1. Estimation of dynamic center of gravity (ZMP) Details of the method for calculating the ZMP as the dynamic center-of-gravity position are described in Japanese Patent No. 6877385, and the main points will be briefly explained below. The dynamic center-of-gravity position estimator 41 performs calculations in two coordinate systems: a world coordinate system (o-xyz system) and a machine-referenced coordinate system (O-XYZ system). The world coordinate system is a coordinate system based on the direction of gravity, with the z-axis pointing in the opposite direction to gravity. The machine-referenced coordinate system is a coordinate system based on the lower running structure 2, with the origin O being the point where the upper rotating structure 3 touches the ground surface on the rotation center line, and the X-axis is set in the longitudinal direction of the lower running structure 2, the Y-axis is set in the lateral direction, and the Z-axis is set in the direction of the rotation center line. The relationship between the world coordinate system and the machine-referenced coordinate system is detected using the vehicle body IMU 13 of the attitude information acquisition device 31.

[0022] The dynamic center-of-gravity position estimator 41 calculates a position vector and an angular velocity vector for each of the lower traveling structure 2, upper rotating structure 3, boom 5, arm 6, and bucket 7 based on the rotation direction, rotation angular velocity, and forward / backward and left / right tilt angles of the upper rotating structure 3 output from the attitude information acquisition device 31, and the rotation angles and angular velocities of the boom 5, arm 6, and bucket 7. For example, the position of the center of gravity of each component of the lower traveling structure 2, upper rotating structure 3, boom 5, arm 6, and bucket 7 is treated as a mass point, and the dynamic center-of-gravity position estimator 41 calculates the position vector and angular velocity vector of each mass point by assuming that the mass of each component is concentrated at each mass point. The dynamic center-of-gravity position estimator 41 then converts the calculated position vector and angular velocity vector into values ​​based on the machine reference coordinate system (O-XYZ).

[0023] The dynamic center of gravity position estimation unit 41 uses the position vectors and acceleration vectors of each mass point converted into the machine reference coordinate system (O-XYZ) to calculate the ZMP (dynamic center of gravity position) of the work machine 1 using the ZMP equation in the following equation (1), which is derived from the balance of moments generated by gravity, inertial force, and external force.

number

[0024] In formula (1), r zmp:ZMP (dynamic center of gravity) position vector m i : mass of the i-th particle r i : position vector of the i-th mass point r'' i :Acceleration vector acting on the i-th mass point (including gravitational acceleration) M j :jth external force moment s k : kth external force application point position vector F k :kth external force vector The vector is a three-dimensional vector consisting of X, Y, and Z components. For example, the ZMP position vector r zmp The X component is Xzmp, the Y component is Yzmp, and the Z component is Zzmp.

[0025] 2. Determining the operator position As described above, the operator position acquisition device 32 receives a signal from the RFID tag 110 worn by the operator as operator position information. The operator position determination unit 42 of the controller 30 determines the position of the operator relative to the work machine 1 based on the operator position information acquired by the operator position acquisition device 32.

[0026] The reception ranges A1 to A4 of the receiving antennas 32a, 32b, 32c, and 32d of the operator position acquisition device 32 are as shown in Figure 3. For example, assuming that an operator wearing RFID 110 is at position P1, position P1 is located within reception range A2, and therefore the radio wave reception strength of the receiving antenna 32b on the left side in the figure is the strongest. Therefore, the operator position determination unit 42 can determine that the operator is on the left side as seen from the work machine 1, based on the radio wave reception strength of each of the receiving antennas 32a to 32d.

[0027] Furthermore, if the operator is at position P2, position P2 is located within both reception ranges A2 and A4, and therefore the radio wave reception strength of both receiving antennas 32b and 32d will be large. Therefore, the operator position determination unit 42 can determine that the operator is located diagonally to the rear left when viewed from the work machine 1. As the receiving antennas 32a to 32d are mounted in four locations on the front, rear, left and right sides of the body 18 in this way, the operator position determination unit 42 can determine in which of the eight directions the operator is located relative to the work machine 1, based on the radio wave reception strength of each of the receiving antennas 32a to 32d.

[0028] <3. Calculation of vehicle stability> The vehicle body stability calculation unit 43 calculates vehicle body stability from the support range L calculated by the support range calculation unit 40, the ZMP (dynamic center of gravity position) calculated by the dynamic center of gravity position estimation unit 41, and the operator position calculated by the operator position determination unit 42. In the work machine 1 of this embodiment, by operating the switching operation unit 172, it is possible to select between on-board operation operation using the indoor operation device 171 and remote operation operation using the remote control operation unit 35.

[0029] (3-1. Calculation of vehicle stability during on-board operation and driving) First, we will explain how to calculate vehicle body stability when the vehicle is operated and driven using the indoor operating device 171. As mentioned above, if the ZMP (Xzmp, Yzmp) goes outside the support range L, the vehicle body 18 will lift up. Therefore, a range is set to warn the operator before the vehicle body 18 actually lifts up. Specifically, as shown in FIG. 4, a high stability range L1 (X-th≦X≦X+th and Y-th≦Y≦Y+th) surrounded by a dashed line is set in the approximate center of the support range L, and the range indicated by symbol L2 around the high stability range L1 is set as a low stability range L2. The high stability range L1 is a range in which the vehicle body stability is determined to be higher than that of the low stability range L2. During the vehicle is operated and driven, vehicle body stability is calculated based on the high stability range L1, and a warning is issued when the ZMP (dynamic center of gravity position) goes outside the high stability range L1.

[0030] When the ZMP (Xzmp, Yzmp) is located within the high stability range L1, the vehicle body stability calculation unit 43 determines that the vehicle body stability is high. When the ZMP (Xzmp, Yzmp) is located within the low stability range L2, the vehicle body stability calculation unit 43 determines that the vehicle body stability is low. As for the method of setting the above-mentioned threshold values X+th, X-th, Y+th, Y-th, for example, it is determined by actually boarding the vehicle body 18 and operating the work machine 1, and setting it to a value at which the operator feels danger from the inclination of the vehicle body 18, etc.

[0031] When the ZMP (Xzmp, Yzmp) deviates from the high stability range L1, that is, when any of Xzmp > X+th, Xzmp < X-th, Yzmp > Y+th, Yzmp < Y-th is satisfied, the buzzer 33 as the information output device generates an alarm sound to alert the operator and the workers around the work machine 1. Also, a warning may be displayed on the monitor display of the remote control operation machine 35 via the communication device 34, or the buzzer of the remote control operation machine 35 may be sounded to give a warning. Furthermore, in addition to warning the operator by the remote control operation machine 35, warning information may be transmitted to the receiving device of the management office 100 via the communication device 34.

[0032] (3-2. Calculation of vehicle body stability during remote operation) Next, the calculation of the vehicle body stability during remote operation performed by the remote control operation machine 35 will be described. When the operator does not board and operates the work machine 1 remotely by the remote control operation machine 35, the operator cannot physically feel the inclination of the work machine 1 because they are not on board the work machine 1. Therefore, the operator will perform remote operation while visually checking the inclination of the work machine 1. However, when the work machine 1 is inclined in the blind spot direction behind the work machine 1, it is difficult to check the inclination, and there is a possibility that it will be noticed later than when it is inclined in other directions.

[0033] For example, if the operator is at position P1 in Figure 3, the right side of the work machine 1, which is opposite the operator across the work machine 1, is in the operator's blind spot. If the vehicle body 18 tilts in the operator's blind spot, it is difficult to visually confirm the tilt of the vehicle body 18, and it takes longer for the operator to realize that the tilt is approaching the danger range than if the tilt is in another direction. Therefore, when operating remotely using the remote control device 35, the high stability range L1 is corrected depending on the direction in which the operator is facing relative to the work machine 1, and warning information about tilt in the blind spot is presented to the operator at an earlier stage.

[0034] When remote control driving is selected by the switching operation unit 172, a post-correction high stability range L11 is generated by the judgment range correction unit 430 of the vehicle body stability calculation unit 43. The judgment range correction unit 430 generates a smaller post-correction high stability range L11 inside the high stability range L1 based on the operator position calculated by the operator position determination unit 42. For example, if the operator is at position P1 in Figure 3, the judgment range correction unit 430 generates a post-correction high stability range L11 as shown in Figure 5. In this case, the low stability range L2 is corrected to a post-correction low stability range L21.

[0035] The corrected high stability range L11 surrounded by the dashed line in FIG. 5 is a range that satisfies the conditions “X-th ≦ X ≦ X+th” and “Y-th ≦ Y ≦ Y+th1”. That is, the threshold value Y+th is corrected to Y+th1. When an operator is at the position P1 on the left side of the working machine 1, the positive direction of the Y-axis on the right side of the working machine 1 becomes the blind spot direction. In that case, correction is made so as to narrow the high stability range L1 on the side of the blind spot direction (the positive side in the Y-axis direction). That is, the threshold value Y+th is corrected to the threshold value Y+th1 (<Y+th). In this case, when the ZMP (Xzmp, Yzmp) is within the corrected high stability range L11, that is, when the conditions “X-th ≦ Xzmp ≦ X+th” and “Y-th ≦ Yzmp ≦ Y+th1” are satisfied, the vehicle body stability is determined to be high. On the other hand, when the ZMP (Xzmp, Yzmp) is outside the corrected high stability range L11, that is, when any of Xzmp > X+th, Xzmp < X-th, Yzmp > Y+th1, and Yzmp < Y-th is satisfied, the vehicle body stability is determined to be low.

[0036] And when the ZMP (Xzmp, Yzmp) is outside the corrected high stability range L11, that is, when any of Xzmp > X+th, Xzmp < X-th, Yzmp > Y+th1, and Yzmp < Y-th is satisfied, an alarm sound is generated by the buzzer 33, and alarm information is transmitted to the remote control operation machine 35 and the management office 100 via the communication device 34. As a result, regarding the inclination of the working machine 1 in the positive direction of the Y-axis (blind spot direction), an alarm is issued earlier in the case of remote operation than in the case of boarding operation, and the safety for preventing falls during remote operation by the operator can be improved.

[0037] FIG. 6 is a diagram showing the post-correction high stability range L11 when the operator operating the remote control unit 35 is at position P2 relative to the work machine 1. For an operator at position P2, which is to the left rear of the work machine 1, the blind spot is to the right front of the work machine 1. In this case, the judgment range correction unit 430 generates the post-correction high stability range L11 by correcting the area including the blind spot of the high stability range L1 (see FIG. 4), which is the area surrounded by the dashed line. In FIG. 6, the post-correction high stability range L11 surrounded by the dashed line is a range that satisfies the conditions "X-th≦X≦X+th1" and "Y-th≦Y≦Y+th1". In other words, the thresholds X+th and Y+th are corrected to X+th1 and Y+th1, respectively.

[0038] As shown in Fig. 3, when receiving antennas 32a to 32d are mounted at four locations on the front, rear, left, and right sides of the vehicle body 18, the operator position determination unit 42 can determine in which of eight directions (front of the vehicle body, front left of the vehicle body, left of the vehicle body, rear left of the vehicle body, rear right of the vehicle body, right of the vehicle body, and front right of the vehicle body) the operator is located relative to the work machine 1, based on the radio wave reception strength of each of the receiving antennas 32a to 32d. In Figs. 5 and 6, the eight directions are shown as operator position P1 (left of the vehicle body), position P2 (rear left of the vehicle body), position P3 (rear of the vehicle body), position P4 (rear right of the vehicle body), position P5 (right of the vehicle body), position P6 (front right of the vehicle body), position P7 (front of the vehicle body), and position P8 (front left of the vehicle body).

[0039] In this case, regarding the correction of the threshold when generating the corrected high stability range L11, whether to correct X+th → X+th1, X-th → X-th1, Y+th → Y+th1, or Y-th → Y-th1 depends on the position of the operator. The thresholds to be corrected at each position P1 to P8 are as follows: Position P1 (left side of vehicle) ... Y-axis positive threshold Y+th Position P2 (rear left of vehicle body)... X-axis positive direction threshold X+th and Y-axis positive direction threshold Y+th Position P3 (rear of vehicle) ... X-axis positive direction threshold X+th Position P4 (rear right of vehicle body)... X-axis positive direction threshold X+th and Y-axis negative direction threshold Y-th Position P5 (right side of the vehicle body) … Y-axis negative direction threshold value Y-th Position P6 (front right of the vehicle body) … X-axis negative direction threshold value X-th and Y-axis negative direction threshold value Y-th Position P7 (front of the vehicle body) … X-axis negative direction threshold value X-th Position P8 (front left of the vehicle body) … X-axis negative direction threshold value X-th and Y-axis positive direction threshold value Y+th

[0040] As described above, in the case of on-vehicle operation driving, when any one of the four conditions "Xzmp > X+th, Xzmp < X-th, Yzmp > Y+th, Yzmp < Y-th" is satisfied, it is determined that the ZMP (Xzmp, Yzmp) is out of the high-stability range L1. On the other hand, in the case of remote operation driving, the threshold values X+th, X-th, Y+th, Y-th in the above four conditions "Xzmp > X+th, Xzmp < X-th, Yzmp > Y+th, Yzmp < Y-th" are corrected for one or two of X+th → X+th1 (< X+th), X-th → X-th1 (> X-th), Y+th → Y+th1 (< Y+th), Y-th → Y-th1 (> Y-th1) according to the positions P1 to P8 as described above.

[0041] Specifically, when the operator's position is at position P1, as shown in FIG. 5, when any of "Xzmp > X + th, Xzmp < X - th, Yzmp > Y + th1, Yzmp < Y - th" is satisfied, it is determined that ZMP(Xzmp, Yzmp) is outside the corrected high-stability range L11. In the case of position P2, as shown in FIG. 6, when any of the conditions "Xzmp > X + th1, Xzmp < X - th, Yzmp > Y + th1, Yzmp < Y - th" is satisfied, it is determined that ZMP(Xzmp, Yzmp) is outside the corrected high-stability range L11. In the case of position P3, when any of the conditions "Xzmp > X + th1, Xzmp < X - th, Yzmp > Y + th, Yzmp < Y - th" is satisfied, it is determined that ZMP(Xzmp, Yzmp) is outside the corrected high-stability range L11. In the case of position P4, when any of "Xzmp > X + th1, Xzmp < X - th, Yzmp > Y + th, Yzmp < Y - th1" is satisfied, it is determined that ZMP(Xzmp, Yzmp) is outside the corrected high-stability range L11.

[0042] In the case of position P5, when any of the conditions "Xzmp > X + th, Xzmp < X - th, Yzmp > Y + th, Yzmp < Y - th1" is satisfied, it is determined that ZMP(Xzmp, Yzmp) is outside the corrected high-stability range L11. In the case of position P6, when any of "Xzmp > X + th, Xzmp < X - th1, Yzmp > Y + th, Yzmp < Y - th1" is satisfied, it is determined that ZMP(Xzmp, Yzmp) is outside the corrected high-stability range L11. In the case of position P7, when any of the conditions "Xzmp > X + th, Xzmp < X - th1, Yzmp > Y + th, Yzmp < Y - th" is satisfied, it is determined that ZMP(Xzmp, Yzmp) is outside the corrected high-stability range L11. In the case of position P8, when any of "Xzmp > X + th, Xzmp < X - th1, Yzmp > Y + th1, Yzmp < Y - th" is satisfied, it is determined that ZMP(Xzmp, Yzmp) is outside the corrected high-stability range L11.

[0043] (Modified Example) In addition, when the threshold values X+th, X-th, Y+th, and Y-th are corrected as described above corresponding to positions P1 to P8, the corrected low stability range L21 for determining that the vehicle body stability is low becomes too large. For some operators performing remote operations, even if the vehicle body 18 tilts in a direction that the operator can confirm, the vehicle body stability may be determined to be low, which may cause annoyance. In such a case, the range setting shown in FIG. 6 may be used as the range setting shown in FIG. 7.

[0044] As shown in FIG. 7, when the operator's position is position P2, the corrected high stability range L11 is the sum of the range satisfying "X+th1≦X≦X+th" and "Y-th≦Y≦Y+th1" and the range satisfying "X-th≦X≦X+th1" and "Y-th≦Y≦Y+th". Therefore, when any one of the four conditions "Xzmp>X+th, Xzmp<X-th, Yzmp>Y+th, Yzmp<Y-th" is satisfied, or when "Xzmp>X+th1" and "Yzmp>Y+th1" are satisfied, it is determined that ZMP(Xzmp, Yzmp) is outside the corrected high stability range L11.

[0045] In the case of position P4, the corrected high stability range L11 is the sum of the range satisfying "X+th1≦X≦X+th" and "Y-th1≦Y≦Y+th" and the range satisfying "X-th≦X≦X+th1" and "Y-th≦Y≦Y+th". Therefore, when any one of the four conditions "Xzmp>X+th, Xzmp<X-th, Yzmp>Y+th, Yzmp<Y-th" is satisfied, or when "Xzmp>X+th1" and "Yzmp<Y-th1" are satisfied, it is determined that ZMP(Xzmp, Yzmp) is outside the corrected high stability range L11.

[0046] In the case of position P6, the post-correction high stability range L11 is the sum of the range satisfying "X-th ≦ X ≦ X-th1" and "Y-th1 ≦ Y ≦ Y+th", and the range satisfying "X-th1 ≦ X ≦ X+th" and "Y-th ≦ Y ≦ Y+th". Therefore, when any one of the four conditions "Xzmp > X+th, Xzmp < X-th, Yzmp > Y+th, Yzmp < Y-th" is satisfied, or when "Xzmp < X-th1" and "Yzmp < Y-th1" are satisfied, it is determined that ZMP(Xzmp, Yzmp) is outside the post-correction high stability range L11. <000021 <000021

[0047] <000021 In the case of position P8, the post-correction high stability range L11 is the sum of the range satisfying "X-th ≦ X ≦ X-th1" and "Y-th ≦ Y ≦ Y+th1", and the range satisfying "X-th1 ≦ X ≦ X+th" and "Y-th ≦ Y ≦ Y+th". Therefore, when any one of the four conditions "Xzmp > X+th, Xzmp < X-th, Yzmp > Y+th, Yzmp < Y-th" is satisfied, or when "Xzmp < X-th1" and "Yzmp > Y+th1" are satisfied, it is determined that ZMP(Xzmp, Yzmp) is outside the post-correction high stability range L11. <000021 <000021

[0048] <000021 <00 When the operator's position is at positions P1, P3, P5, or P7, it is the same as in the above-described embodiment, and the description is omitted. In the above-described FIGS. 5 to 7, the operator position determination unit 42 determined eight positions P1 to P8 regarding the operator's position. This is because, as shown in FIG. 3, the reception antennas 32a to 32d are arranged on the front, rear, left, and right of the vehicle body 18. That is, since the determinable operator positions depend on the number and arrangement of the reception antennas, the setting of the determinable operator positions and the post-correction high stability range L11 is not limited to the form shown in FIGS. 5 to 7. <000021 <000021

[0049] <000021 According to the embodiments and modified examples of the present invention described above, the following operational effects are achieved. <000021 <000022

[0050] <000022 (C1) As shown in Figures 1, 2, 5, 6, etc., the work machine 1 comprises a vehicle body 18, a front work implement 4 attached to the vehicle body 18, an attitude information acquisition device 31 that acquires attitude information (angles (or angular velocities) of three axes and acceleration) of the vehicle body 18 and the front work implement 4, and an operator position acquisition device 32 that acquires position information of an operator who remotely operates the vehicle body 18. The work machine 1 further comprises a dynamic center-of-gravity position estimation unit 41 that estimates the dynamic center-of-gravity position (ZMP) of the work machine 1 based on the attitude information, a support range calculation unit 40 that calculates a support range L formed by the ground contact points of the vehicle body 18 based on dimensional information of the vehicle body 18, an operator position determination unit 42 that determines the relative position of the operator with respect to the vehicle body 18 (positions P1 to P8) from the position information acquired by the operator position acquisition device 32, a determination range setting unit 431 that sets a stability determination range (high stability range L1) inside the support range L, and an operator position determination unit 432. The system is equipped with a judgment range correction unit 430 that corrects the high stability range L1 based on the operator's position calculated by the unit 42 to generate a narrower corrected stability judgment range (corrected high stability range L11), a vehicle body stability calculation unit 43 that determines that the stability of the vehicle body 18 is high if the dynamic center of gravity position (ZMP) is within the corrected high stability range L11, and that the stability of the vehicle body 18 is low if the dynamic center of gravity position (ZMP) is not within the corrected high stability range L11, and an information output device (buzzer 33) that outputs judgment information of the vehicle body stability calculation unit 43.

[0051] As described above, the work machine 1 corrects the high stability range L1 based on the operator's position to generate a narrower corrected high stability range L11, and if the ZMP is not within the corrected high stability range L11, it determines that the stability of the vehicle body 18 is low and outputs this determination information. This allows the operator remotely operating the work machine 1 to grasp the risk of the work machine 1 tipping over earlier using the output determination information, thereby improving tipping safety during remote operation. In particular, it makes it easy to grasp the risk of the work machine 1 tipping over in blind spots, which are difficult to determine visually. Methods for outputting the determination information include generating an alarm sound from the buzzer 33 provided on the vehicle body 18, presenting alarm information via the remote control device 35, or transmitting alarm information to the management office 100 via the communication device 34.

[0052] (C2) In (C1) above, as shown in Figures 1 and 2, if the vehicle body stability calculation unit 43 determines that stability is low, the buzzer 33, which is an information output device, outputs an alarm sound around the vehicle body 18. As a result, not only the operator but also workers working around the work machine can be notified of the risk of the work machine 1 tipping over, and they can be encouraged to take action to avoid the danger.

[0053] (C3) In (C1) above, as shown in Figures 5 to 7, the judgment range correction unit 430 corrects the stability judgment range (high stability range L1) so as to narrow the range in the direction opposite the operator across the vehicle body 18. Because the direction opposite the operator across the vehicle body 18 is a blind spot, it is very difficult to visually determine the risk of tipping over in the blind spot of the work machine 1. For this reason, by using a corrected high stability range L11 obtained by correcting the high stability range L1 so as to narrow the range in the direction opposite the operator, it is possible to grasp the risk of tipping over in the blind spot at an earlier stage.

[0054] (C4) In (C1) above, as shown in Fig. 2 etc., a remote control device (remote control device 35) is provided for the operator to drive and operate the vehicle body 18 remotely, and the information output device (communication device 34) outputs determination information to the remote control device 35, which in turn presents the determination information to the operator. The determination information presented by the remote control device 35 allows the operator to recognize earlier the risk of the work machine 1 tipping over in a blind spot that is difficult to judge visually, and makes it possible to prevent tipping from occurring.

[0055] (C5) In (C1) above, as shown in Figures 1, 2, 4 to 6, etc., there is provided a remote control device (remote control operation machine 35) for an operator to drive and operate the vehicle body 18 remotely, and a switching operation unit 172 for switching between remote control operation by the remote control operation machine 35 and on-board operation operation by an operation device (indoor operation device 171) of the vehicle body 18, and when switched to remote operation operation by the switching operation unit 172, the vehicle body stability calculation unit 43 makes a judgment based on the corrected stability judgment range (corrected high stability range L11), and when switched to on-board operation operation by the switching operation unit 172, makes a judgment based on the stability judgment range (high stability range L1) instead of the corrected high stability range L11.

[0056] In this way, with the above-described configuration, the level of stability is determined based on the post-correction high stability range L11 suitable for remote operation during remote control operation, and the level of stability is determined based on the pre-correction high stability range L1 suitable for on-board operation during on-board operation operation. Therefore, optimal stability determination can be performed in both remote control operation and on-board operation operation.

[0057] The above-described embodiments and modifications are merely examples, and the present invention is not limited to these unless the features of the invention are impaired. Other embodiments that are conceivable within the scope of the technical idea of ​​the present invention are also included within the scope of the present invention. [Explanation of symbols]

[0058] 1...work machine, 2...lower running body, 3...upper rotating body, 4...front working machine, 5...boom, 6...arm, 7...bucket, 13...vehicle body IMU, 14...boom IMU, 15...arm IMU, 16...bucket IMU, 17...cab, 18...vehicle body, 30...controller, 31...posture information acquisition device, 32...operator position acquisition device, 33...buzzer (information output device), 34...communication device, 35...remote control device (remote operation device), 40...Support range calculation unit, 41...Dynamic center of gravity position estimation unit, 42...Operator position determination unit, 43...Vehicle stability calculation unit, 100...Administration office, 110...RFID tag, 171...Indoor operation device, 172...Switching operation unit, 430...Determination range correction unit, 431...Determination range setting unit, L...Support range, L1...High stability range (stability determination range), L2...Low stability range, L11...Corrected high stability range (corrected stability determination range), L21...Corrected low stability range

Claims

1. The car body and a work machine attached to the vehicle body; a posture information acquisition device for acquiring posture information of the vehicle body and the work machine; a control device that controls the vehicle body and the work implement based on the attitude information acquired by the attitude information acquisition device, an operator position information acquisition device that acquires position information of an operator who remotely operates the vehicle body; The control device a dynamic center-of-gravity position estimating unit that estimates a dynamic center-of-gravity position of the work machine based on the posture information; a support range calculation unit that calculates a support range formed by ground contact points of the vehicle body based on the dimensional information of the vehicle body; an operator position determination unit that determines a relative position of the operator with respect to the vehicle body from the position information acquired by the operator position information acquisition device; a determination range setting unit that sets a stability determination range inside the support range; a judgment range correction unit that corrects the stability judgment range based on the position of the operator calculated by the operator position determination unit to generate a narrower corrected stability judgment range; a vehicle body stability calculation unit that determines that the stability of the vehicle body is high when the dynamic center-of-gravity position is within the corrected stability determination range, and determines that the stability of the vehicle body is low when the dynamic center-of-gravity position is not within the corrected stability determination range; an information output device that outputs determination information from the vehicle body stability calculation unit; Equipped with the determination range correction unit corrects the stability determination range so that a range on an opposite side of the vehicle body from the position of the operator becomes narrower; The information output device outputs the determination information when the vehicle body stability calculation unit determines that the stability of the vehicle body is low. A work machine characterized by:

2. 2. The work machine according to claim 1, the information output device outputs the determination information to an operation device; The operating device presents the determination information to the operator of the work machine.

3. 2. The work machine according to claim 1, A switching operation unit is provided for switching between remote control operation and on-board operation using an operation device of the vehicle body, The vehicle body stability calculation unit When the switching operation is performed to the remote control operation by the switching operation unit, the determination is made based on the corrected stability determination range, When the switching operation unit switches to the boarding operation operation, the determination is made based on the stability determination range instead of the corrected stability determination range. Work machinery.

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