CN118202122A - Work machine, method of controlling work machine, and system - Google Patents

Abstract

The work machine is provided with: a vehicle body; a travel wheel; a steering actuator; a hinge actuator; a steering angle sensor; a hinge angle sensor; an object sensor; and a controller. The vehicle body comprises: a rear frame; and a front frame. The front frame is connected to the rear frame so as to be rotatable left and right. The steering actuator steers the running wheel left and right. The hinge actuator changes a hinge angle between the front frames of the rear frames. The object sensor detects an object around the work machine and outputs a signal indicating the presence or absence of the object. The controller sets a detection range around the work machine. The controller sets the detection range according to the steering angle and the articulation angle.

Description

Work machine, method of controlling work machine, and system

Technical Field

The present disclosure relates to work machines, methods of controlling work machines, and systems.

Background

Conventionally, in a work machine, a technique for detecting a person or an obstacle around the work machine by a sensor such as a radar is used. For example, patent document 1 discloses a forklift equipped with an object detection system. The object detection system includes a radar device such as a millimeter wave radar. The radar device detects whether or not an object is present by transmitting an electric wave or an ultrasonic wave, and receiving an electric wave or an ultrasonic wave reflected by the object.

In the object detection system, when all objects that intrude into the measurable range of the radar device are detected and an alarm is given, the alarm is frequently given. Therefore, in the object detection system described above, the controller sets a detection range around the forklift, and when an object is detected within the detection range, the controller issues an alarm. In addition, the detection range varies according to the speed and steering angle of the forklift truck.

Prior art literature

Patent literature: japanese patent application laid-open No. 2021-28266

Disclosure of Invention

Problems to be solved by the invention

In the object detection system, the detection range is changed according to the vehicle speed and the steering angle, and thus it can be appropriately determined whether or not an object is present around the forklift. However, it is not sufficient to apply only the above-described technique to a work machine having a large degree of freedom in the posture of the vehicle body, such as a motor grader. The purpose of the present invention is to appropriately determine whether or not an object is present in the vicinity of a work machine.

Means for solving the problems

A work machine according to a first aspect of the present invention includes: a vehicle body; a travel wheel; a steering actuator; a hinge actuator; a steering angle sensor; a hinge angle sensor; an object sensor; and a controller. The vehicle body includes: a rear frame; and a front frame. The front frame is connected to the rear frame so as to be rotatable left and right. The running wheel is supported by the vehicle body. The steering actuator steers the running wheel left and right. The hinge actuator changes a hinge angle between the rear frame and the front frame. The steering angle sensor detects a steering angle of the running wheel. The hinge angle sensor detects a hinge angle. The object sensor detects an object around the work machine and outputs a signal indicating the presence or absence of the object. The controller sets a detection range around the work machine. The controller determines whether an object is present in the detection range based on a signal from the object sensor. The controller sets the detection range according to the steering angle and the articulation angle.

A method according to a second aspect of the present invention is a method for controlling a work machine. The work machine includes: a rear frame; a vehicle body; a travel wheel; a steering actuator; an articulated actuator. The vehicle body includes: a rear frame; and a front frame. The front frame is connected to the rear frame so as to be rotatable left and right. The running wheel is supported by the vehicle body. The steering actuator steers the running wheel left and right. The hinge actuator changes a hinge angle between the rear frame and the front frame. The method comprises the following steps: detecting a steering angle; detecting a hinge angle; receiving a signal indicating the presence or absence of an object in the vicinity of the work machine; setting a detection range of the periphery of the working machine according to the steering angle and the hinging angle; based on the signal from the object sensor, the presence or absence of an object in the detection range is determined.

The system according to the third aspect of the present invention is a system for controlling a work machine. The work machine includes: a rear frame; a vehicle body; a travel wheel; a steering actuator; an articulated actuator. The vehicle body includes: a rear frame; and a front frame. The front frame is connected to the rear frame so as to be rotatable left and right. The running wheel is supported by the vehicle body. The steering actuator steers the running wheel left and right. The hinge actuator changes a hinge angle between the rear frame and the front frame. The system is provided with: a steering angle sensor; a hinge angle sensor; an object sensor; and a controller. The steering angle sensor detects a steering angle of the running wheel. The hinge angle sensor detects a hinge angle. The object sensor detects an object around the work machine and outputs a signal indicating the presence or absence of the object. The controller sets a detection range around the work machine. The controller determines whether an object is present in the detection range based on a signal from the object sensor. The controller sets the detection range according to the steering angle and the articulation angle.

Effects of the invention

In the present invention, the detection range of the peripheral object of the work machine is set based on the steering angle and the articulation angle. This makes it possible to appropriately determine whether or not an object is present around the work machine.

Drawings

Fig. 1 is a perspective view showing a work machine according to an embodiment.

Fig. 2 is a side view showing a work machine.

Fig. 3 is a plan view showing a front portion of the work machine.

Fig. 4 is a front view showing the front of the work machine.

Fig. 5 is a schematic diagram showing a configuration of a control system of the work machine.

Fig. 6 is a plan view showing an example of the detection range.

Fig. 7 is a flowchart showing a process for setting the detection range.

Fig. 8 is a flowchart showing a process for setting the detection range.

Fig. 9 is a plan view showing a detection range according to the process of modification 1.

Fig. 10 is a plan view showing a detection range according to the process of modification 2.

Fig. 11 is a plan view showing a detection range according to the process of modification 3.

Fig. 12 is a plan view showing a detection range according to the process of modification 3.

Fig. 13 is a plan view showing the detection range according to the process of modification 4.

Fig. 14 is a plan view showing the detection range according to the process of modification 5.

Fig. 15 is a plan view showing the detection range according to the process of modification 5.

Fig. 16 is a plan view showing the detection range according to the process of modification 6.

Fig. 17 is a plan view showing the detection range according to the processing of modification 7.

Fig. 18 is a plan view showing the detection range according to the processing of modification 7.

Fig. 19 is a plan view showing the detection range according to the processing of modification 8.

Fig. 20 is a plan view showing a detection range according to the process of modification 8.

Fig. 21 is a plan view showing a detection range according to the process of modification 9.

Fig. 22 is a plan view showing the detection range according to the process of modification 9.

Fig. 23 is a plan view showing a detection range according to the process of modification 9.

Fig. 24 is a plan view showing the detection range according to the process of modification 9.

Fig. 25 is a plan view showing the detection range of the modification.

Detailed Description

Embodiments of the present invention will be described with reference to the following drawings. Fig. 1 is a perspective view showing a work machine 1 according to an embodiment. Fig. 2 is a side view of the work machine 1. As shown in fig. 1, the work machine 1 includes: a vehicle body 2; travel wheels 3a,3b,4a-4D; work machine 5. The vehicle body 2 includes: a front frame 11; a rear frame 12; a driving unit 13; a power chamber 14.

The rear frame 12 is connected to the front frame 11. The front frame 11 is rotatably coupled to the rear frame 12 with respect to the rear frame 12. As will be described later, the front frame 11 is rotatable to the left and right with respect to the rear frame 12.

In the following description, in each of the front-rear, left-right directions of the vehicle body 2, the front frame 11 and the rear frame 12 are defined as being straight in a state where the hinge angle of the front frame 11 with respect to the rear frame 12 is zero.

The driving unit 13 and the power chamber 14 are disposed on the rear frame 12. The driver 13 is provided with a driver seat, not shown. The power chamber 14 is disposed behind the driving unit 13. The front frame 11 extends forward from the rear frame 12.

The running wheels 3a,3b,4a-4D are rotatably supported on the vehicle body 2. The running wheels 3a,3b,4a-4D include: front wheels 3a,3b; rear wheels 4A-4D. The front wheels 3a,3b are disposed apart from each other in the left-right direction. Front wheels 3a,3b are mounted to the front frame 11. Rear wheels 4A-4D are mounted to rear frame 12.

Work implement 5 is movably connected to vehicle body 2. The work machine 5 includes: a support member 15; blade 16. The support member 15 is movably connected to the vehicle body 2. The support member 15 supports a blade 16. The support member 15 includes: a drawbar 17 and a rotating disc 18. The traction lever 17 is disposed below the front frame 11.

The drawbar 17 is connected to a front portion 19 of the front frame 11. The drawbar 17 extends rearward from a front portion 19 of the front frame 11. The traction lever 17 is supported swingably with respect to the front frame 11 in at least the up-down direction and the left-right direction of the vehicle body 2. Such as the front portion 19 comprising a ball joint. The traction lever 17 is rotatably connected with respect to the front frame 11 via a ball joint.

The rotary disk 18 is connected to the rear of the drawbar 17. The rotary disk 18 is rotatably supported with respect to the traction lever 17. Blade 16 is connected to rotating disk 18. Blade 16 is supported by a drawbar 17 via a rotating disc 18. As shown in fig. 2, blade 16 is rotatably supported on rotary disk 18 about tilt axis 21. The tilt shaft 21 extends in the left-right direction.

Fig. 3 is a plan view of the front portion of the work machine 1. As shown in fig. 3, the work machine 1 includes: a first steering shaft 43A; the second steering shaft 43B. The first steering shaft 43A and the second steering shaft 43B are provided to the front frame 11. The first steering shaft 43A and the second steering shaft 43B extend in the up-down direction. The front wheel 3A is rotatably supported about the first steering shaft 43A. The front wheel 3B is rotatably supported about the second steering shaft 43B. That is, the front wheels 3a,3b are steerable running wheels.

The work machine 1 includes: a plurality of steering actuators 41a,41b for steering the front wheels 3a,3b. A plurality of steering actuators 41a,41b are used to steer the front wheels 3a,3b. For example, the plurality of steering actuators 41a,41b may be hydraulic cylinders. A plurality of steering actuators 41a,41b are connected to the front wheels 3a,3b, respectively. The plurality of steering actuators 41a,41b are expanded and contracted by oil pressure. In the following description, the expansion and contraction of the hydraulic cylinder including the plurality of steering actuators 41a,41b is referred to as "stroke operation".

The plurality of steering actuators 41a,41b includes: a left steering cylinder 41A; right steering cylinder 41B. The left steering cylinder 41A and the right steering cylinder 41B are disposed apart from each other in the left-right direction.

The left steering cylinder 41A is connected to the front frame 11 and the front wheels 3A. The right steering cylinder 41B is connected to the front frame 11 and the front wheels 3B. The front wheels 3a,3B are steered according to the stroke motions of the left steering cylinder 41A and the right steering cylinder 41B.

The work machine 1 includes: and a hinge shaft 44. The hinge shaft 44 is provided to the front frame 11 and the rear frame 12. The hinge shaft 44 extends in the up-down direction. The front frame 11 and the rear frame 12 are rotatably connected to each other about a hinge shaft 44.

In the following description, a state in which the front frame 11 and the rear frame 12 are rotated about the hinge shaft 44 to bend the vehicle body 2 is referred to as a "hinge state". In addition, a state that is not in a hinge state, that is, a state in which the front frame 11 and the rear frame 12 are aligned in a straight line is referred to as a "straight line state".

The work machine 1 includes: a plurality of hinge actuators 27, 28. A plurality of hinge actuators 27, 28 are used to rotate the front frame 11 relative to the rear frame 12. For example, the plurality of articulated actuators 27, 28 are hydraulic cylinders. A plurality of hinge actuators 27, 28 are connected to the front frame 11 and the rear frame 12. The plurality of hinge actuators 27, 28 are extended and contracted by oil pressure.

The plurality of hinge actuators 27, 28 includes: a left articulated cylinder 27; right hinge cylinder 28. The left hinge cylinder 27 and the right hinge cylinder 28 are disposed apart from each other in the left-right direction.

The left hinge cylinder 27 is connected to the front frame 11 and the rear frame 12 on the left side of the vehicle body 2. The right hinge cylinder 28 is connected to the front frame 11 and the rear frame 12 on the right side of the vehicle body 2. The front frame 11 is rotated left and right with respect to the rear frame 12 by the stroke motion of the left and right hinge cylinders 27 and 28.

Fig. 4 is a front view of the front of the work machine 1. As shown in fig. 4, the work machine 1 includes: and a tilting mechanism 6. The tilting mechanism 6 tilts the front wheels 3a,3b to the left and right. The tilting mechanism 6 includes: a front bridge 56; a roll bar 57; a roll actuator 60. The front bridge 56 extends from the front frame 11 to the left and right. The front bridge 56 is rotatably supported by the front frame 11 about a pivot 58.

The front bridge 56 is connected to the front wheels 3A via wheel brackets 59A. The front bridge 56 rotatably supports the front wheels 3A about the roll axis 54A. The front bridge 56 is connected to the front wheels 3B via wheel brackets 59B. The front bridge 56 rotatably supports the front wheels 3B about the roll axis 54B. The roll shafts 54a,54b extend in the front-rear direction.

The roll bar 57 extends leftward and rightward through the front frame 11. The roll bar 57 connects the front wheels 3a,3b to each other. The roll bar 57 is connected to the front wheels 3A via a wheel bracket 59A. The roll bar 57 is connected to the front wheels 3B via a wheel bracket 59B.

The roll actuator 60 is used to tip (roll) the front wheels 3a,3b. The roll actuator 60 is, for example, a hydraulic cylinder. The roll actuator 60 is connected to the front frame 11 and the front wheels 3a,3b. The roll actuator 60 expands and contracts by oil pressure. That is, the front wheels 3a,3b are rotated about the roll axes 54a,54b by the expansion and contraction of the roll actuator 60. Thus, the front wheels 3a,3b are tilted to the left and right.

As shown in fig. 2, the work machine 1 includes: a plurality of actuators 22-26 for changing the posture of work machine 5. For example. The plurality of actuators 22-25 are hydraulic cylinders. The actuator 26 is a rotary actuator. In the present embodiment, the actuator 26 is a hydraulic motor. The actuator 26 may also be an electric motor.

A plurality of actuators 22-25 are coupled to work implement 5. The plurality of actuators 22-25 are expanded and contracted by oil pressure. The plurality of actuators 22 to 25 are extended and retracted to change the posture of the work implement 5 with respect to the vehicle body 2.

In detail, the plurality of actuators 22-25 includes: a left lift cylinder 22; a right lift cylinder 23; a drawbar shift cylinder 24; blade tilting cylinder 25.

The left lift cylinder 22 and the right lift cylinder 23 are disposed apart from each other in the left-right direction. The left and right lift cylinders 22, 23 are connected to the traction rod 17. The left and right lift cylinders 22, 23 are connected to the front frame 11 via a lifter bracket 29. The traction rod 17 swings up and down according to the stroke motions of the left and right lift cylinders 22 and 23. Thereby, the blade 16 moves up and down.

The drawbar shift cylinder 24 is connected to the drawbar 17 and the front frame 11. The drawbar shift cylinder 24 is connected to the front frame 11 via a lifter bracket 29. The drawbar shift cylinder 24 extends obliquely downward from the front frame 11 toward the drawbar 17. The drawbar 17 swings left and right according to the stroke operation of the drawbar shift cylinder 24.

Blade tilt cylinders 25 are connected to the rotating disc 18 and blade 16. Blade 16 rotates about tilt axis 21 in accordance with the stroke of blade tilt cylinder 25.

An actuator 26 is connected to the drawbar 17 and the rotating disc 18. The actuator 26 rotates the rotary disk 18 relative to the drawbar 17. Thereby, blade 16 rotates about the rotation axis extending in the up-down direction.

Fig. 5 is a schematic diagram showing a configuration of a control system of the work machine 1. As shown in fig. 5, the work machine 1 includes: a drive source 31; a hydraulic pump 32; a power transmission device 33. The work machine 1 includes: a steering valve 42A; a hinge valve 42B; a roll valve 42C; work implement valve 34. The drive source 31 is, for example, an internal combustion engine. Alternatively, the drive source 31 may be an electric motor or a hybrid of an internal combustion engine and an electric motor.

The hydraulic pump 32 is driven by the drive source 31, and discharges hydraulic oil. The hydraulic pump 32 supplies hydraulic oil to the steering valve 42A, the articulation valve 42B, the roll valve 42C, and the work implement valve 34. Thus, the plurality of steering actuators 41a,41b, the plurality of articulation actuators 27, 28, the roll actuator 60, and the plurality of actuators 22-26 are operated. In fig. 5, only one hydraulic pump 32 is shown, but a plurality of hydraulic pumps may be provided.

The steering valve 42A is connected to the hydraulic pump 32 and the plurality of steering actuators 41a,41b via an oil pressure circuit. The steering valve 42A controls the flow rate of the hydraulic oil supplied from the hydraulic pump 32 to the plurality of steering actuators 41a,41b. The plurality of steering actuators 41a,41b perform a stroke operation by supplying the hydraulic oil of the hydraulic pump 32 to the steering valve 42A.

The articulated valve 42B is connected to the hydraulic pump 32 and the plurality of articulated actuators 27, 28 via an oil pressure circuit. The articulated valve 42B controls the flow rate of the hydraulic oil supplied from the hydraulic pump 32 to the plurality of articulated actuators 27, 28. The plurality of articulated actuators 27, 28 perform a stroke operation by supplying the hydraulic oil of the hydraulic pump 32 to the articulated valve 42B.

The roll valve 42C is connected to the hydraulic pump 32 and the roll actuator 60 via a hydraulic circuit. The roll valve 42C controls the flow rate of the hydraulic oil supplied from the hydraulic pump 32 to the roll actuator 60. By supplying the hydraulic oil of the hydraulic pump 32 to the roll valve 42C, the roll actuator 60 performs a stroke operation.

Work implement valve 34 is connected to hydraulic pump 32 and to plurality of actuators 22-26 via an oil pressure circuit. Work implement valve 34 includes: a plurality of valves respectively connected to the plurality of actuators 22-26. Work implement valve 34 controls the flow rate of hydraulic oil supplied from hydraulic pump 32 to the plurality of actuators 22-26.

The power transmission device 33 transmits the driving force from the driving source 31 to the rear wheels 4A-4D. The power transmission device 33 may also include a torque converter and/or a plurality of speed change gears. Alternatively, the power transmission device 33 may be a transmission such as HST (Hydraulic Static Transmission) or HMT (Hydraulic Mechanical Transmission).

The work machine 1 includes: a steering operation member 45; a hinge operation member 46; a roll operation member 47; work machine operating member 48; a shift operating member 49; an accelerator operation member 50.

The steering operation member 45 is operable by an operator to steer the front wheels 3a,3 b. The steering operation member 45 is a lever such as a joystick. Alternatively, the steering operation member 45 may be a member other than a lever. For example, the steering operation member 45 may be a steering wheel. The steering operation member 45 outputs a steering operation signal indicating an operation of the steering operation member 45 by an operator.

The hinge operation member 46 can be operated by an operator to rotate the front frame 11 with respect to the rear frame 12. The hinge operation member 46 is a lever such as a joystick. Or the hinge operation member 46 may be a member other than a lever. The hinge operation member 46 outputs a hinge operation signal indicating an operation of the hinge operation member 46 by an operator.

The roll operating member 47 can be operated by an operator to tip the front wheels 3a,3 b. The roll operating member 47 is a lever such as a joystick. Alternatively, the roll operation member 47 may be a switch or other member such as a touch panel. The roll operation member 47 outputs a roll operation signal indicating an operation of the roll operation member 47 by the operator.

Work implement operating member 48 is operable by an operator to change the posture of work implement 5. Work machine operating member 48 includes, for example, a plurality of work machine bars. Alternatively, work implement operating member 48 may be a switch or other member such as a touch panel. Work implement operation member 48 outputs a signal indicating an operation of work implement operation member 48 by the operator.

The shift operating member 49 is operable by an operator to switch between forward and reverse of the work machine 1. The shift operating member 49 includes, for example, a shift lever. Alternatively, the shift operating member 49 may be a switch or other member such as a touch panel. The shift operating member 49 outputs a signal indicating an operation of the shift operating member 49 by the operator.

The accelerator operation member 50 is operable by an operator to cause the work machine 1 to travel. The accelerator operation member 50 includes, for example, an accelerator pedal. Alternatively, the accelerator operation member 50 may be a switch or other member such as a touch panel. The accelerator operation member 50 outputs a signal indicating an operation of the accelerator operation member 50 by an operator.

As shown in fig. 5, the work machine 1 includes: a controller 37. The controller 37 includes: a storage device 38; a processor 39. The processor 39 is, for example, a CPU, and executes a program for controlling the work machine 1. The storage device 38 includes: storage such as RAM and ROM, and auxiliary storage such as SSD or HDD. The storage device 38 stores programs and data for controlling the work machine 1.

The controller 37 controls the power transmission device 33 in accordance with the operation of the shift operating member 49. Thereby, the traveling direction of the work machine 1 can be switched between forward and backward. In addition, the speed stage of the power transmission device 33 can be switched. Or the shift operating member 49 can be mechanically coupled to the power transmission device 33. The forward and reverse gears of the power transmission device 33 or the speed change gear may be switched by mechanically transmitting the operation of the shift operation member 49 to the power transmission device 33.

The controller 37 controls the drive source 31 and the power transmission device 33 in accordance with the operation of the accelerator operation member 50. Thereby, the work machine 1 is driven. The controller 37 controls the hydraulic pump 32 and the work implement valve 34 in accordance with the operation of the work implement operation member 48. Thereby, work implement 5 is operated.

The controller 37 obtains the operation amount of the steering operation member 45 based on the steering operation signal from the steering operation member 45. The controller 37 controls the steering valve 42A in accordance with the steering operation signal, thereby expanding and contracting the plurality of steering actuators 41a,41 b. Thereby, the controller 37 changes the steering angle θs of the front wheels 3a,3 b.

As shown in fig. 3, the steering angle θs is an angle by which the front wheels 3A,3B are turned relative to the front frame 11 about the first steering shaft 43A and the second steering shaft 43B. In detail, the steering angle θs is a rotation angle of the front wheels 3a,3b with respect to the first center line L1 of the front frame 11. The first center line L1 extends in the front-rear direction of the front frame 11.

The steering angle θs is changed from the neutral position to the left and right in accordance with the stroke operation of the plurality of steering actuators 41a,41 b. The steering angle θs in the neutral position is zero degrees. The front wheels 3a,3b are arranged parallel to the first center line L1 of the front frame 11 in the neutral position. In fig. 3, 3A 'and 3B' show the front wheels in a state in which the steering angle θs is steered rightward from the neutral position.

The controller 37 obtains the operation amount of the hinge operation member 46 based on the hinge operation signal from the hinge operation member 46. The controller 37 controls the hinge valve 42B. For example, the controller 37 controls the hinge valve 42B according to the hinge operation signal, thereby telescoping the left and right hinge cylinders 27 and 28. Thereby, the controller 37 changes the hinge angle θa.

As shown in fig. 3, the hinge angle θa is an angle by which the front frame 11 rotates with respect to the rear frame 12 about the hinge shaft 44. In detail, the hinge angle θa is an angle formed by the first center line L1 of the front frame 11 and the second center line L2 of the rear frame 12.

The second center line L2 extends in the front-rear direction of the rear frame 12. The second center line L2 passes through the hinge shaft 44 when the work machine 1 is viewed from above. The hinge angle θa changes from the neutral position to the left and right. The articulation angle θa of the neutral position is zero. The hinge angle θa in the left direction is a positive value, and the hinge angle θa in the right direction is a negative value.

In the case where the hinge angle θa is zero, the direction of the second center line L2 coincides with the direction of the first center line L1. That is, when the hinge angle θa is zero, the vehicle body 2 is in a straight line state. In fig. 3, the front frame 11 is shown rotated by the hinge angle θa about the hinge shaft 44.

The controller 37 obtains the operation amount of the roll operation member 47 based on the roll operation signal from the roll operation member 47. The controller 37 controls the roll valve 42C. For example, the controller 37 controls the roll valve 42C according to the roll operation signal to extend and retract the roll actuator 60. Thereby, the controller 37 changes the roll angle θl in accordance with the operation of the roll operation member 47 by the operator.

As shown in fig. 4, the roll angle θl is a tilting angle in the lateral direction of the front wheels 3a,3b when the vehicle body 2 is viewed from the front. For example, when the vehicle body 2 is viewed from the front, the roll angle θl is a tilting angle at which the front wheels 3a,3b tilt about the roll axes 54a,54 b.

In the following description, a state in which the front wheels 3a,3b stand upright with respect to the horizontal plane (3 a,3b shown by solid lines) is referred to as a neutral position of the front wheels 3a,3 b. The front wheels 3a,3b are in neutral position and the roll angle thetal is zero degrees. In fig. 4, 3A ',3B' show the front wheel inclined leftward by the roll angle θl from the neutral position.

The work machine 1 includes: a steering angle sensor 51; a hinge angle sensor 52; a roll angle sensor 53. The steering angle sensor 51 is for detecting a steering angle θs of the front wheels 3a,3 b. The steering angle sensor 51 outputs a signal indicating the steering angle θs.

The hinge angle sensor 52 is used to detect the hinge angle of the front frame 11 with respect to the rear frame 12. The hinge angle sensor 52 outputs a signal indicating the hinge angle θa. The roll angle sensor 53 is for detecting the roll angle θl of the front wheels 3a,3 b. The roll angle sensor 53 outputs a signal indicating the roll angle θl.

The steering angle sensor 51, the articulation angle sensor 52, and the roll angle sensor 53 may be IMUs (inertial measurement units). Alternatively, the steering angle sensor 51, the articulation angle sensor 52, and the roll angle sensor 53 may be cameras, respectively. In this case, the controller 37 may calculate the steering angle θs and the articulation angle θa and the roll angle θl by analyzing the images acquired by the respective sensors 51 to 53.

Alternatively, the steering angle sensor 51, the articulation angle sensor 52, and the roll angle sensor 53 may be sensors that detect the stroke amounts of the steering actuators 41a,41b, the stroke amounts of the articulation cylinders 27, 28, and the stroke amounts of the roll actuators 60, respectively. In this case, the controller 37 may calculate the steering angle θs, the articulation angle θa, and the roll angle θl based on the stroke amounts of the steering actuators 41a,41b, the stroke amounts of the articulation cylinders 27, 28, and the stroke amount of the roll actuator 60, respectively.

Or the steering angle sensor 51 may directly detect the steering angle θs. The hinge angle sensor 52 may directly detect the hinge angle θa. The roll angle sensor 53 may directly detect the roll angle θl.

As shown in fig. 5, the work machine 1 includes: object sensors 61, 62; and an output device 63. The object sensors 61 and 62 detect objects around the work machine 1. The object sensors 61, 62 are radar devices such as millimeter wave radar. Alternatively, the object sensors 61 and 62 may be other types of sensors such as ultrasonic sensors, cameras, and LIDAR (Light Detection AND RANGING) devices. The object sensor outputs a signal indicating the presence or absence of a peripheral object of the work machine 1.

The object sensors 61, 62 include: a first object sensor 61; a second object sensor 62. The first object sensor 61 detects an object in front of the vehicle body 2. The first object sensor 61 is mounted to, for example, the front frame 11. Alternatively, the first object sensor 61 may be mounted in another place such as the driver 13. The second object sensor 62 detects an object behind the vehicle body 2. The second object sensor 62 is attached to, for example, the rear frame 12, or the second object sensor 62 may be attached to the driver 13 or other positions of the power chamber 14.

The output device 63 is, for example, a display. The output device 63 displays an image in accordance with a command signal from the controller 37. Or the output device 63 may be a speaker. The output device 63 may output a voice according to a command signal from the controller 37.

The controller 37 sets detection ranges 71 and 72 around the work machine 1, and determines whether or not an object is present in the detection ranges 71 and 72 based on signals from the object sensors 61 and 62. For example, as shown in fig. 6, the controller 37 sets a first detection range 71 in front of the vehicle body 2. The controller 37 sets the second detection range 72 at the rear of the vehicle body 2. When the object 100 is detected within the detection ranges 71 and 72, the controller 37 causes the output device 63 to output an alarm.

The controller 37 stores a first reference range 73 of the first detection range 71 and a second reference range 74 of the second detection range 72. The first reference range 73 and the second reference range 74 are set based on a width (hereinafter, referred to as "vehicle width") L0 of the vehicle body 2. The width of the first reference range 73 and the width of the second reference range 74 are the same as the maximum vehicle width L0 of the work machine 1 except for the work implement 5, respectively.

The controller 37 sets the detection ranges 71, 72 according to the steering angle θs, the articulation angle θa, and the roll angle θl. The controller 37 changes the detection ranges 71, 72 from the reference ranges 73, 74 according to the steering angle θs, the articulation angle θa, and the roll angle θl. A method for setting the detection ranges 71 and 72 by the controller 37 will be described below. Fig. 7 and 8 are flowcharts showing the processing executed by the controller 37 to set the detection ranges 71 and 72.

As shown in fig. 7, in step S1, the controller 37 obtains a steering angle θs. The controller 37 obtains the steering angle θs from the signal from the steering angle sensor 51. In step S2, the controller 37 acquires the hinge angle θa. The controller 37 obtains the hinge angle θa from the signal from the hinge angle sensor 52. In step S3, the controller 37 acquires the roll angle θl. The controller 37 obtains the roll angle θl from the signal from the roll angle sensor 53.

In step S4, the controller 37 determines whether the steering angle θs is 0 degrees. In step S5, the controller 37 determines whether the hinge angle θa is 0 degrees. In step S6, the controller 37 determines whether the roll angle θl is 0 degrees.

In the case where the steering angle θs, the articulation angle θa, and the roll angle θl are 0 degrees, the controller 37 sets the reference ranges 73, 74 as the detection ranges 71, 72 in step S7. That is, when the working machine 1 is traveling in a straight line without turning or rolling, the controller 37 sets the reference ranges 73 and 74 as the detection ranges 71 and 72. In detail, as shown in fig. 6, the controller 37 sets the first reference range 73 as the first detection range 71. In addition, the controller 37 sets the second reference range 74 as the second detection range 72.

In step S6, if the roll angle θl is not 0 degrees, the process proceeds to step S8. In step S8, the controller 37 sets the detection ranges 71, 72 by changing the reference ranges 73, 74 in accordance with the processing of the modification 1. Fig. 9 is a plan view showing detection ranges 71 and 72 according to the processing of modification 1.

As shown in fig. 9, in the process of modification 1, the controller 37 expands the detection ranges 71, 72 to the same side as the direction in which the front wheels 3a,3b roll in the left-right direction (hereinafter referred to as "roll direction"). That is, when the working machine 1 is not steered and is traveling straight while rolling in a straight state, the controller 37 expands the detection ranges 71 and 72 to the same side as the rolling direction.

For example, in the case where the front wheels 3a,3b are tilted to the left, the controller 37 expands the first detection range 71 to the left from the first reference range 73. The controller 37 expands the second detection range 72 from the second reference range 74 to the left. The controller 37 does not expand the detection ranges 71 and 72 rightward. In this case, the widths Lall of the detection ranges 71 and 72 are expressed by the following expression (1).

Lall＝L0+Ll (1)

Ll is the increment of the detection range at the time of roll. The roll increment Ll represents the displacement amount of the front wheels 3a,3b in the lateral direction outward due to the roll. The roll increment Ll is expressed by the following expression (2).

Ll＝D×cosθl (2)

As shown in fig. 4, D is the outer diameter of the front wheels 3a,3 b. Although not shown, in the process of modification 1, when the front wheels 3a,3b are tilted to the right, the controller 37 expands the first detection range 71 to the right from the first reference range 73 and expands the second detection range 72 to the right from the second reference range 74.

In step S5, in the case where the hinge angle θa is not 0 degrees, the process advances to step S9. In step S9, the controller 37 determines whether the roll angle θl is 0 degrees. In step S9, when the roll angle θl is 0 degrees, the process advances to step S10.

In step S10, the controller 37 sets the detection ranges 71, 72 by changing the reference ranges 73, 74 in accordance with the processing of the modification 2. Fig. 10 is a plan view showing detection ranges 71 and 72 according to the processing of modification 2. As shown in fig. 10, in the process of modification 2, the controller 37 bends the detection ranges 71 and 72 according to the turning radius of the work machine 1 corresponding to the articulation angle θa. That is, when the work machine 1 turns in the articulated state without turning or rolling, the detection ranges 71 and 72 are curved in accordance with the turning paths A1 and A2 of the work machine 1.

For example, when the work machine 1 turns to the left in the articulated state, the controller 37 bends the detection ranges 71 and 72 to the left. The controller 37 stores data indicating a relationship between the articulation angle θa and the turning radius of the work machine 1, and can calculate the turning radius from the articulation angle θa by referring to the data. The widths Lall of the detection ranges 71 and 72 are the same as the widths of the reference ranges 73 and 74, as shown in the following equation (3).

Lall＝L0 (3)

Although not shown, in the process of modification 2, when the work machine 1 turns right in the articulated state, the controller 37 bends the detection ranges 71 and 72 to the right.

In step S9, in the case where the roll angle θl is not 0 degrees, the process advances to step S11. In step S11, the controller 37 sets the detection ranges 71 and 72 by changing the reference ranges 73 and 74 in accordance with the processing of the change 3. Fig. 11 and 12 are plan views showing detection ranges 71 and 72 according to the processing of modification 3.

As shown in fig. 11 and 12, in the process of modification 3, the controller 37 bends the detection ranges 71 and 72 according to the turning radius of the work machine 1 corresponding to the articulation angle θa and the roll angle θl, and expands the detection ranges 71 and 72 to the same side as the roll direction. That is, when the work machine 1 turns in the articulated state while not turning, the controller 37 bends the detection ranges 71 and 72 in accordance with the turning locus of the work machine 1 and enlarges the detection ranges 71 and 72 to the same side as the roll direction, as in the process of modification 2. For example, the controller 37 may store data indicating a relationship between the articulation angle θa and the roll angle θl and the turning radius of the work machine 1, and calculate the turning radius of the work machine 1 from the articulation angle θa and the roll angle θl by referring to the data.

For example, as shown in fig. 11, when the work machine 1 turns left while being tilted left in an articulated state, the controller 37 bends the detection ranges 71 and 72 to the left, and expands the detection ranges 71 and 72 to the left by the increment Ll. As shown in fig. 12, when the work machine 1 turns left in an articulated state while rolling right, the controller 37 bends the detection ranges 71 and 72 to the left and expands the detection ranges 71 and 72 to the right by the increment Ll. The width Lall of the detection ranges 71, 72 is expressed by the above expression (1).

Although not shown, in the process of modification 3, when the working machine 1 turns right in the articulated state, the controller 37 bends the detection ranges 71 and 72 to the right and expands the detection ranges 71 and 72 to the same side as the roll direction.

In step S4, in the case where the steering angle θs is not 0 degrees, the process proceeds to step S12 shown in fig. 8. In step S12, the controller 37 determines whether the hinge angle θa is 0 degrees. In step S13, the controller 37 determines whether the roll angle θl is 0 degrees. In the case where both the articulation angle θa and the roll angle θl are 0 degrees, the process advances to step S14.

In step S14, the controller 37 sets the detection ranges 71 and 72 by changing the reference ranges 73 and 74 in accordance with the processing of the change 4. Fig. 13 is a plan view showing detection ranges 71 and 72 according to the processing of modification 4. As shown in fig. 13, in the process of modification 4, the controller 37 bends the detection ranges 71 and 72 according to the turning radius of the work machine 1 corresponding to the steering angle θs. That is, when the work machine 1 is turned by steering in a straight line without rolling, the detection ranges 71 and 72 are curved in accordance with the turning locus of the work machine 1.

For example, as shown in fig. 13, when the work machine 1 turns left by turning, the controller 37 bends the detection ranges 71 and 72 to the left. For example, the controller 37 may store data indicating a relationship between the steering angle θs and the turning radius of the work machine 1, and calculate the turning radius from the steering angle θs by referring to the data. The widths Lall of the detection ranges 71 and 72 are the same as the widths of the reference ranges 73 and 74, as shown in the above formula (3). Although not shown, in the process of modification 4, when the work machine 1 turns right by turning, the controller 37 bends the detection ranges 71 and 72 to the right.

In step S13, in the case where the roll angle θl is not 0 degrees, the process advances to step S15. In step S15, the controller 37 sets the detection ranges 71 and 72 by changing the reference ranges 73 and 74 in accordance with the processing of the change 5. Fig. 14 and 15 are plan views showing detection ranges 71 and 72 according to the processing of modification 5.

As shown in fig. 14 and 15, in the process of modification 5, the controller 37 bends the detection ranges 71 and 72 according to the turning radius of the work machine 1 corresponding to the steering angle θs and the roll angle θl, and expands the detection ranges 71 and 72 to the same side as the roll direction. That is, when the work machine 1 turns by steering while rolling in a straight state, the controller 37 bends the detection ranges 71 and 72 in accordance with the turning locus of the work machine 1, and expands the detection ranges 71 and 72 to the same side as the rolling direction. The controller 37 stores data indicating a relationship between the steering angle θs and the roll angle θl and the turning radius of the work machine 1, and can calculate the turning radius of the work machine 1 from the steering angle θs and the roll angle θl by referring to the data.

For example, as shown in fig. 14, when the work machine 1 turns left by turning to the left while rolling to the left, the controller 37 bends the detection ranges 71 and 72 to the left and expands the detection ranges 71 and 72 to the left by the increment Ll. As shown in fig. 15, when the work machine 1 turns left by turning while rolling to the right, the controller 37 bends the detection ranges 71 and 72 to the left and expands the detection ranges 71 and 72 to the right by the increment Ll. The width Lall of the detection ranges 71, 72 is expressed by the above formula (1).

Although not shown, in the process of modification 5, when the work machine 1 turns right by turning, the controller 37 bends the detection ranges 71 and 72 to the right and expands the detection ranges 71 and 72 to the same side as the roll direction.

In step S12, in the case where the hinge angle θa is not 0 degrees, the process advances to step S16. In step S16, the controller 37 determines whether the steering angle θs and the value opposite to the positive and negative of the articulation angle θa are the same (i.e., θs= - θa). In the case where the steering angle θs is the same as the value opposite to the positive and negative of the articulation angle θa, the process advances to step S17. In step S17, the controller 37 determines whether the roll angle θl is 0 degrees. In the case where the roll angle θl is 0 degrees, the process advances to step S18.

In step S18, the controller 37 changes the reference ranges 73 and 74 in accordance with the processing of the change 6, thereby setting the detection ranges 71 and 72. Fig. 16 is a plan view showing detection ranges 71 and 72 according to the processing of modification 6.

As shown in fig. 16, when the steering angle θs is equal to or opposite to the articulation angle θa, the work machine 1 moves straight in the articulated state. In the process of modification 6, the controller 37 expands the reference ranges 73, 74 in the right-left direction according to the hinge angle θa. The controller 37 expands the first detection range 71 from the first reference range 73 on the opposite side to the bending direction (hereinafter, referred to as "hinge direction") of the front frame 11 with respect to the rear frame 12 in the left-right direction. In addition, the controller 37 expands the second detection range 72 from the second reference range 74 on the same side as the hinge direction.

For example, as shown in fig. 16, when the work machine 1 is straight in a state in which the front frame 11 is bent leftward with respect to the rear frame 12, the controller 37 expands the first detection range 71 rightward from the first reference range 73 and expands the second detection range 72 leftward from the second reference range 74. In this case, the widths Lall of the detection ranges 71, 72 are expressed by the following expression (4).

Lall＝L0+La (4)

La is the increment of the detection range in the hinge state. As shown in fig. 4, the increment La in the articulated state indicates the displacement amount of the front wheels 3a,3b in the articulated state to the outside in the left-right direction. The increment La in the hinge state is represented by the following formula (5).

La＝Lf×sinθa (5)

As shown in fig. 3, lf is the distance between the hinge shaft 44 and the center P1 of the front bridge 56. Although not shown, in the process of modification 6, when the front frame 11 is straight in a state of being bent rightward with respect to the rear frame 12, the controller 37 expands the first detection range 71 leftward from the first reference range 73, and expands the second detection range 72 rightward from the second reference range 74.

In step S17, in the case where the roll angle θl is not 0 degrees, the process advances to step S19. In step S19, the controller 37 sets the detection ranges 71 and 72 by changing the reference ranges 73 and 74 in accordance with the processing of the change 7. Fig. 17 and 18 are plan views showing detection ranges 71 and 72 according to the processing of modification 7.

As shown in fig. 17, in the process of the modification 7, the controller 37 expands the reference ranges 73, 74 in the right-left direction according to the hinge angle θa, and expands the detection ranges 71, 72 on the same side as the roll direction. That is, when the work machine 1 is tilted and is moving straight in the articulated state, the controller 37 expands the detection ranges 71 and 72 from the reference ranges 73 and 74 in the right-left direction according to the articulation angle θa, and expands the detection ranges 71 and 72 from the reference ranges 73 and 74 on the same side as the tilt direction.

For example, as shown in fig. 17, when the work machine 1 is traveling straight in a left-hand articulated state while being tilted to the left, the controller 37 expands the first detection range 71 to the right by an increment La and expands the first detection range 71 to the left by an increment Ll. The controller 37 further expands the second detection range 72 by an increment La to the left and expands the second detection range 72 by an increment Ll to the left. In this case, the widths Lall of the detection ranges 71, 72 are expressed by the following expression (6).

Lall＝L0+La+Ll (6)

However, as shown in fig. 18, when the roll direction is opposite to the hinge direction, the controller 37 does not perform the increment Ll when the roll is enlarged for the detection ranges 71, 72. That is, the controller 37 performs the process of the modification 7 described above when the roll direction is the same as the hinge direction.

Although not shown, in the process of modification 7, when the front frame 11 is straight in the rightward hinge state while being tilted rightward, the controller 37 expands the first detection range 71 by the increment La leftward and expands the first detection range 71 by the increment Ll rightward. The controller 37 expands the second detection range 72 rightward by the increment La and expands the second detection range 72 rightward by the increment Ll.

In step S16, in the case where the steering angle θs and the value opposite to the positive and negative of the articulation angle θa are different (i.e., θs+.θa), the process proceeds to step 20.

In step S20, the controller 37 determines whether the roll angle θl is 0 degrees. In the case where the roll angle θl is 0 degrees, the process advances to step S21. In step S21, the detection ranges 71 and 72 are set by changing the reference ranges 73 and 74 in accordance with the processing of the change 8. Fig. 19 and 20 are plan views showing detection ranges 71 and 72 according to the processing of modification 8.

As shown in fig. 19, in the process of modification 8, when the turning direction and the articulated direction of the work machine 1 are the same, the controller 37 bends the detection ranges 71 and 72 according to the turning radius of the work machine 1 corresponding to the articulated angle θa and the steering angle θs. That is, when the work machine 1 turns at the steering angle θs according to the articulation angle θa in the non-roll state, the detection ranges 71 and 72 are curved in accordance with the turning locus of the work machine 1.

For example, when the work machine 1 turns to the left (θs > - θa) based on the articulation angle θa and the steering angle θs, the controller 37 bends the detection ranges 71, 72 to the left. The controller 37 stores data indicating the relationship between the articulation angle θa and the steering angle θs and the turning radius of the work machine 1, and may calculate the turning radius from the articulation angle θa and the steering angle θs by referring to the data. The widths Lall of the detection ranges 71 and 72 are the same as the widths of the reference ranges 73 and 74, as shown in the above formula (3).

Although not shown, in the process of modification 8, the turning direction and the articulated direction of work machine 1 are the same, and when work machine 1 turns to the right (θs < - θa) based on the articulated angle θa and the steering angle θs, controller 37 bends detection ranges 71 and 72 to the right.

As shown in fig. 20, in the process of modification 8, when the steering angle θs is different from the value opposite to the positive and negative values of the articulation angle θa and the turning direction and the articulation direction of the work machine 1 are opposite, the controller 37 bends the detection ranges 71 and 72 according to the turning radius of the work machine 1 corresponding to the articulation angle θa and the steering angle θs and expands the reference ranges 73 and 74 in the left-right direction according to the articulation angle θa.

For example, as shown in fig. 20, when the articulation direction is left and the turning direction of the work machine 1 is right, the controller 37 expands the first detection range 71 rightward from the first reference range 73 and bends the first detection range 71 rightward. Further, the controller 37 expands the second detection range 72 from the second reference range 74 to the left, and bends the second detection range 72 to the right. In this case, the width Lall of the detection ranges 71, 72 is expressed by the above formula (4).

Although not shown, in the process of modification 8, when the steering angle θs and the articulation angle θa are different in positive and negative values and the articulation direction is right, and the turning direction of the work machine 1 is left, the controller 37 expands the first detection range 71 from the first reference range 73 to the left and bends the first detection range 71 to the left. Further, the controller 37 expands the second detection range 72 from the second reference range 74 to the right, and bends the second detection range 72 to the left.

In step S20, in the case where the roll angle θl is not 0 degrees, the process advances to step S22. In step S22, the controller 37 sets the detection ranges 71 and 72 by changing the reference ranges 73 and 74 in accordance with the processing of the change 9. Fig. 21 to 24 are plan views showing detection ranges 71 and 72 according to the processing of modification 9.

As shown in fig. 21 and 22, in the process of modification 9, when the articulation direction and the turning direction of the work machine 1 are the same, the controller 37 bends the detection ranges 71, 72 according to the turning radius of the work machine 1 corresponding to the articulation angle θa, the steering angle θs, and the roll angle θl, and expands the detection ranges 71, 72 on the same side as the roll direction. That is, when turning based on the articulation angle θa and the steering angle θs while rolling, the controller 37 may bend the detection ranges 71 and 72 in accordance with the turning locus of the work machine 1 and expand the detection ranges 71 and 72 on the same side as the rolling direction. The controller 37 stores data indicating the relationship between the articulation angle θa, the steering angle θs, the roll angle θl, and the turning radius of the work machine 1, and calculates the turning radius of the work machine 1 from the articulation angle θa, the steering angle θs, and the roll angle θl by referring to the data.

For example, as shown in fig. 21, when the work machine 1 turns to the left based on the articulation angle θa and the steering angle θs while rolling to the left, the controller 37 bends the detection ranges 71 and 72 to the left and expands the detection ranges 71 and 72 to the left by the increment Ll. As shown in fig. 22, when the work machine 1 turns to the left based on the articulation angle θa and the steering angle θs while rolling to the right, the controller 37 bends the detection ranges 71 and 72 to the left and expands the detection ranges 71 and 72 to the right by the increment Ll. The width Lall of the detection ranges 71, 72 is expressed by the above expression (1).

Although not shown, in the process of modification 9, when the work machine 1 turns right in the same direction as the turning direction of the work machine 1, the controller 37 bends the detection ranges 71 and 72 to the right, and expands the detection ranges 71 and 72 on the same side as the roll direction.

As shown in fig. 23, in the process of modification 9, when the articulation direction is opposite to the turning direction of the work machine 1 and the roll direction is the same as the articulation direction, the controller 37 bends the detection ranges 71 and 72 according to the turning radius of the work machine 1 corresponding to the articulation angle θa, the steering angle θs, and the roll angle θl, expands the reference ranges 73 and 74 in the right-left direction according to the articulation angle θa, and expands the detection ranges 71 and 72 on the same side as the roll direction.

For example, as shown in fig. 23, when the articulation direction is left, the turning direction of the work machine 1 is right, and the roll direction is left, the controller 37 expands the first detection range 71 from the first reference range 73 to the right by the increment La in the articulated state, expands the first detection range 71 from the first reference range 73 to the left by the increment Ll in the roll state, and bends the first detection range 71 to the right. The controller 37 expands the second detection range 72 from the second reference range 74 to the left by an increment La, expands the second detection range 72 from the second reference range 74 to the left by an increment Ll, and bends the second detection range 72 to the right. In this case, the widths Lall of the detection ranges 71, 72 are expressed by the above formula (6).

Note that, although not shown, when the articulation direction is right, the turning direction of the work machine 1 is left, and the roll direction is right, the controller 37 expands the first detection range 71 from the first reference range 73 by an increment La to the left, expands the first detection range 71 from the first reference range 73 by an increment Ll to the right, and bends the first detection range 71 to the left. The controller 37 expands the second detection range 72 by an increment La rightward from the second reference range 74, expands the second detection range 72 by an increment Ll rightward from the second reference range 74, and bends the second detection range 72 leftward.

However, as shown in fig. 24, in the process of modification 9, when the articulation direction is opposite to the turning direction of the work machine 1 and the roll direction is opposite to the articulation direction, the increment Ll at the time of extending the detection ranges 71 and 72 is not performed. In this case, the width Lall of the detection ranges 71, 72 is expressed by the above formula (4).

In the work machine 1 of the present embodiment described above, the detection ranges 71 and 72 of the objects around the work machine 1 are set based on the articulation angle θa, the roll angle θl, and the steering angle θs. This makes it possible to appropriately determine whether or not an object is present around the work machine 1.

Although the above description has been given of one embodiment of the present invention, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the gist of the present invention.

The structure of the work machine 1 is not limited to the above, and may be modified. For example, the structure of work implement 5 may be changed. A part of the control system of the work machine 1 may be disposed outside the work machine 1. For example, the various operating members 46-50 and the output device 63 of the work machine 1 may be disposed outside the work machine 1.

The controller 37 may be constituted by a plurality of controllers. The above-described processing may be distributed to a plurality of controllers for execution. A part of the plurality of controllers may be disposed outside the work machine 1.

The processing in the case where the object is detected in the detection ranges 71, 72 is not limited to the above embodiment, and may be modified. For example, when an object is detected in the detection ranges 71 and 72, the controller 37 may perform processing such as stopping the work implement 3 and/or the vehicle body 2, or restricting the operation.

The process for setting the detection ranges 71, 72 is not limited to the above embodiment, and may be modified. The controller 37 may set only the detection range to any one of the front and rear of the vehicle body 2. When the work machine 1 advances, the controller 37 may set the first detection range 71 in front of the vehicle body 2. When the work machine 1 is retracted, the controller 37 may set the second detection range 72 to the rear of the vehicle body 2.

The threshold values of the articulation angle θa, the steering angle θs, and the roll angle θl used in the process for determining the change of the detection ranges 71 and 72 are not limited to 0 degrees, and may be other values. For example, the threshold value of the articulation angle θa may be a small value that makes the work machine 1 be regarded as a straight state. The threshold value of the steering angle θs may be a small value such that the work machine 1 is regarded as not being steered to the left or right. The threshold value of the roll angle θl may be a small value such that the work machine 1 is regarded as not being tilted. The change of the detection ranges 71, 72 according to the roll direction may be omitted.

The controller 37 may add an arbitrary margin width in consideration of the detection error to the width Lall of the above-described detection ranges 71, 72. For example, as shown in fig. 25, the controller 37 may set the detection ranges 71 and 72 by adding the margin width Lt to the left and right of the reference ranges 73 and 74. The remaining margin widths Lt may be added to the left and right detection ranges 71 and 72, respectively, similarly to the detection ranges 71 and 72 determined by the processing of the above-described modifications 1 to 9.

In the above embodiment, the vehicle width of the front portion and the vehicle width of the rear portion of the vehicle body 2 are the same, but the vehicle width of the front portion and the vehicle width of the rear portion of the vehicle body 2 may be different. In this case, the controller 37 may calculate the width of the first detection range 71 using the front vehicle width as the width of the first reference range 73. The controller 37 may calculate the width of the second detection range 72 using the vehicle width at the rear as the width of the second reference range 74.

Industrial applicability

According to the present invention, it is possible to appropriately determine whether or not an object is present in the periphery of the work machine.

Description of the reference numerals

2: Vehicle bodies, 3a,3b: travel wheel, 11: front frame, 12: rear frame, 27, 28: hinge actuator, 37: controllers, 41a,41b: steering actuator, 51: steering angle sensor, 52: hinge angle sensor, 53: roll angle sensor, 60: roll actuators, 61, 62: object sensors, 71, 72: detection range, 73, 74: reference range, θa: hinge angle, θl: roll angle, θs: steering angle.

Claims (19)

1. A working machine is characterized by comprising:

A vehicle body including a rear frame and a front frame rotatably connected to the rear frame in a left-right direction;

A travel wheel supported by the vehicle body;

A steering actuator for steering the running wheel to the left and right;

A hinge actuator that changes a hinge angle between the rear frame and the front frame;

a steering angle sensor that detects a steering angle of the running wheel;

A hinge angle sensor that detects the hinge angle;

An object sensor that detects an object around the work machine and outputs a signal indicating the presence or absence of the object;

A controller that sets a detection range around the work machine, determines whether or not the object is present in the detection range based on a signal from the object sensor,

The controller sets the detection range according to the steering angle and the articulation angle.

2. The work machine of claim 1 wherein,

The controller sets a reference range of the detection range based on the width of the vehicle body,

And changing the detection range from the reference range according to the hinge angle.

3. The work machine of claim 2 wherein,

In the case where the work machine turns according to the articulation angle, the controller bends the detection range according to a turning radius of the work machine corresponding to the articulation angle.

4. A work machine according to claim 2 or 3, wherein,

When the direction of the articulation angle is opposite to the turning direction of the work machine, the controller expands the detection range from the reference range to the right and left directions according to the articulation angle.

5. The work machine of claim 4 wherein,

When the detection range is set in front of the front frame, the controller expands the detection range from the reference range in the left-right direction with respect to the front frame on the same side as the rear frame.

6. The work machine of claim 4 wherein,

When the detection range is set rearward of the rear frame, the controller expands the detection range from the reference range with respect to the rear frame on the same side as the front frame in the left-right direction.

7. The work machine according to claim 2, further comprising:

a roll actuator that changes a roll angle of the travel wheel;

A roll angle sensor that detects the roll angle,

The controller changes the detection range from the reference range according to the roll angle.

8. The work machine of claim 7 wherein,

The controller expands the detection range from the reference range on the same side in the left-right direction as the traveling wheel rolling direction.

9. The work machine of claim 8 wherein,

When the turning direction of the work machine is opposite to the direction of the articulation angle and the direction in which the traveling wheel is tilted coincides with the turning direction of the work machine, the controller does not expand the detection range corresponding to the roll angle.

10. A method for controlling a work machine, characterized in that,

The work machine includes: a vehicle body including a rear frame and a front frame rotatably connected to the rear frame in a left-right direction; a travel wheel supported by the vehicle body; a steering actuator for steering the running wheel to the left and right; a hinge actuator that changes a hinge angle between the rear frame and the front frame, the method comprising:

Detecting a steering angle of the running wheel;

detecting the articulation angle;

Receiving a signal indicating the presence or absence of an object in the vicinity of the work machine;

Setting a detection range at a periphery of the work machine based on the steering angle and the articulation angle;

and determining whether the object is present in the detection range based on a signal from the object sensor.

11. The method as set forth in claim 10, further comprising:

Setting a reference range of the detection range based on a width of the vehicle body;

and changing the detection range from the reference range according to the hinge angle.

12. The method as set forth in claim 11, further comprising:

When the work machine turns according to the articulation angle, the detection range is curved according to a turning radius of the work machine corresponding to the articulation angle.

13. The method according to claim 11 or 12, further comprising:

When the direction of the articulation angle is opposite to the turning direction of the work machine, the detection range is widened from the reference range to the left and right directions according to the articulation angle.

14. The method as set forth in claim 13, further comprising:

When the detection range is set in front of the front frame, the detection range is widened from the reference range on the same side as the rear frame with respect to the front frame in the left-right direction.

15. The method as set forth in claim 13, further comprising:

When the detection range is set to the rear of the rear frame, the detection range is widened from the reference range on the same side as the front frame with respect to the rear frame in the left-right direction.

16. The method of claim 11, wherein,

The work machine further includes: a roll actuator for changing a roll angle of the running wheel,

The method further comprises the steps of:

detecting the roll angle;

And changing the detection range from the reference range according to the roll angle.

17. The method as set forth in claim 16, further comprising:

the detection range is enlarged from the reference range on the same side in the left-right direction as the direction in which the running wheel is tilted.

18. The method of claim 17, wherein,

The turning direction of the work machine is opposite to the direction of the articulation angle, and the detection range corresponding to the roll angle is not enlarged when the direction of the travel wheel roll matches the turning direction of the work machine.

19. A system for controlling a work machine, characterized by:

the work machine includes: a vehicle body having a rear frame and a front frame connected to the rear frame so as to be rotatable left and right; a travel wheel supported by the vehicle body; a steering actuator for steering the running wheel to the left and right; a hinge actuator that changes a hinge angle between the rear frame and the front frame, the system including:

a steering angle sensor that detects a steering angle of the running wheel;

A hinge angle sensor that detects the hinge angle;

An object sensor that detects an object around the work machine and outputs a signal indicating the presence or absence of the object;

A controller that sets a detection range around the work machine, determines whether or not the object is present in the detection range based on a signal from the object sensor,

The controller sets the detection range according to the steering angle and the articulation angle.