Patent Application
20220282459
The present invention relates to an operation assistance system for a work machine.
In a work machine with a work implement, such as a hydraulic excavator, an operation assistance function is known, which detects a worker or an obstacle around the work machine, notifies the result of detection to an operator, or decelerates and stops the operation of the work implement in order to prevent the work machine from coming into contact with the worker or the obstacle around the work machine (Patent Literature 1).
In the work machine, a work assistance function is also known, which controls the work implement so that the work implement does not go out of a work area set in advance, including a height, a depth, a turning angle, or the like (Patent Literature 2).
Using such a work assistance function can prevent the work implement from coming into contact with and destroying electric wires or underground objects and may improve work efficiency. In addition, when there is a limitation on the area in a turning direction, the work assistance function can prevent the work implement from running over a road during the work performed on the roadside of the road, for example.
However, in the case of a work machine incorporating both operation assistance and work assistance functions described above, an area of the operation assistance function and an area (work area) of the work assistance function need be set individually, and an operator or the like may find such area setting inconvenient. In addition, when an area of the operation assistance function is set inside of a work area or the operator forgets to enable the operation assistance function, the operator may fail to recognize an object entering the work area, resulting in a collision of the work machine with the object.
The present invention provides an operation assistance system for a work machine having both operation assistance and work assistance functions, capable of reducing the inconvenience to an operator or the like of setting an area of the operation assistance function and an area of the work assistance function, and preventing a collision of the work machine with an object in a work area.
In view of the foregoing, the operation assistance system for a work machine of the present invention has the operation assistance function of stopping the work machine when an object is detected in a stop area set in advance based on detection information from a detection device that detects an object around the work machine with a work implement and the work assistance function of preventing the work machine from going out of a work area set in advance based on attitude information of the work machine. When the work area is set, the operation assistance system sets the work area as the stop area.
According to the present invention, it is possible to reduce the inconvenience to an operator or the like of setting an area of the operation assistance function and an area of the work assistance function, and prevent a collision of the work machine with an object in a work area.
Other problems, configurations, and advantageous effects will become apparent from the following description of embodiments.
Hereinafter, embodiments of the present invention will be described with reference to the drawings. Parts having the same function are denoted by the same reference numbers throughout the drawings, and repeated description thereof may be omitted. It should be noted that the present embodiments describe the hydraulic excavator as one of the examples of the work machine. However, as long as the work machine can incorporate both operation assistance and work assistance functions, the present invention is not limited to the hydraulic excavator and can be applied generally to the work machines, such as wheel loaders, cranes, bulldozers, dumps, or road machines.
The turning body 3 includes a cab 4, a machine room 5, and a counterweight 6. The cab 4 is provided on the left side of the front part of the turning body 3. The machine room 5 is provided on the rear side of the cab 4. The counterweight 6 is provided on the rear side of the machine room 5, that is, at the rear end of the turning body 3.
In addition, the turning body 3 is equipped with a work implement 7. The work implement 7 is provided on the right side of the cab 4, at the center of the front part of the turning body 3. The work implement 7 includes a boom 8, an arm 9, a bucket 10, a boom cylinder 11, an arm cylinder 12, and a bucket cylinder 13. The proximal end of the boom 8 is rotatably attached to the front part of the turning body 3 via a boom pin. The proximal end of the arm 9 is rotatably attached to the distal end of the boom 8 via an arm pin. The proximal end of the bucket 10 is rotatably attached to the distal end of the arm 9 via a bucket pin. Further, the boom cylinder 11, the arm cylinder 12, and the bucket cylinder 13 are hydraulic cylinders each driven by the hydraulic oil. The boom cylinder 11 drives the boom 8. The arm cylinder 12 drives the arm 9. The bucket cylinder 13 drives the bucket 10. This allows the hydraulic excavator 1 to perform digging operation, loading operation, and the like at construction sites.
A turning motor 14 is disposed at the center of the turning body 3. Driving the turning motor 14 allows the turning body 3 to rotate with respect to the traveling body 2.
In addition, a left traveling motor 15a and a right traveling motor 15b are disposed in the traveling body 2. Driving the left traveling motor 15a and the right traveling motor 15b allows the traveling body 2 to travel while driving the left and right crawlers.
Hereinafter, the boom cylinder 11 for boom driving, the arm cylinder 12 for arm driving, the bucket cylinder 13 for bucket driving, the turning motor 14 for turning operation, and the left traveling motor 15a and the right traveling motor 15b for traveling operation may be referred to as the actuator of the hydraulic excavator 1. In addition, the traveling body 2 and the turning body 3 may be collectively referred to as the body of the hydraulic excavator 1.
A hydraulic pump 16 and an engine (prime mover) 17 are disposed inside of the machine room 5 (see
A body inclination sensor 18 is attached to the inside of the cab 4, a boom inclination sensor 19 is attached to the boom 8, an arm inclination sensor 20 is attached to the arm 9, and a bucket inclination sensor 21 is attached to the bucket 10. The body inclination sensor 18, the boom inclination sensor 19, the arm inclination sensor 20, and the bucket inclination sensor 21 are IMUs (Inertial Measurement Unit), for example. The body inclination sensor 18, the boom inclination sensor 19, the arm inclination sensor 20, and the bucket inclination sensor 21 measure a ground angle of the body, a ground angle of the boom 8, a ground angle of the arm 9, and a ground angle of the bucket 10, respectively. Further, a first GNSS antenna 23 and a second GNSS antenna 24 are attached to the rear part of the turning body 3 on the right and left sides. With signals obtained from the first GNSS antenna 23 and the second GNSS antenna 24, positional information of the body can be obtained.
In addition, a detection device 25 is attached to the turning body 3. The detection device 25 detects an object (obstacle) around the hydraulic excavator 1. In this example, the detection device 25 includes four devices: a front side detection device 25a for detecting an obstacle on the front side, a right side detection device 25b for detecting an obstacle on the right side, a rear side detection device 25c for detecting an obstacle on the rear side, and a left side detection device 25d for detecting an obstacle on the left side. In addition,
The detection device 25 is a stereo camera, for example, and can calculate a distance from the hydraulic excavator 1 to an obstacle (an object to be detected). Further, the detection device 25 may be any device as long as it can measure a distance to the object to be detected, such as a millimeter wave radar or a laser radar, or a device using magnetic field, for example.
In the hydraulic excavator 1, the actuator (11, 12, 13, 14, 15a, 15b) is driven by being supplied with hydraulic oil ejected from the hydraulic pump 16 driven by the engine 17. The amount and direction of the oil supplied to the actuator can be controlled by driving a flow rate control valve in a flow rate control valve unit 33.
For example, a turning flow rate control valve 34 is a flow rate control valve for controlling the amount of oil supplied to the turning motor 14. When the turning flow rate control valve 34 moves to the left in the figure, oil is supplied so that the turning motor 14 rotates to the left. The rotation speed of the turning motor 14 can be controlled according to the movement amount of the turning flow rate control valve 34. Meanwhile, when the turning flow rate control valve 34 moves to the right in the figure, oil is supplied so that the turning motor 14 rotates to the right.
The control of the turning flow rate control valve 34 is performed by controlling a solenoid proportional pressure reducing valve in a solenoid proportional pressure reducing valve unit 35. The solenoid proportional pressure reducing valve decompresses oil supplied from a pilot pump 37 and supplies the oil to the flow rate control valve according to an instruction from a controller 27.
For example, when a leftward turning solenoid proportional pressure reducing valve 36a is driven, the pressure oil is supplied so that the turning flow rate control valve 34 moves to the left in the figure. When a rightward turning solenoid proportional pressure reducing valve 36b is driven, the pressure oil is supplied so that the turning flow rate control valve 34 moves to the right in the figure.
Though not shown, the controller 27 is configured as a computer including a CPU (Central Processing Unit) that executes various operations, a storage unit such as a ROM (Read Only Memory), a HDD (Hard Disk Drive), or the like that stores programs for executing the operations by the CPU, a RAM (Random Access Memory) serving as a work area when the CPU executes the programs. The CPU loads various programs stored in the storage unit into the RAM and executes the programs so that the functions of the controller 27 are implemented.
The controller 27 calculates and outputs control signals to the solenoid proportional pressure reducing valve unit 35, the hydraulic pump 16, and a buzzer 28 based on a signal from a control lever 32, a signal from a monitor 31, a signal from the detection device 25 (detection information), a signal from the attitude sensor 30 including the turning angle sensor 22 and the like (attitude information), and a signal from a switch 29.
The control lever 32, the monitor 31, and the switch 29 are each disposed inside of the cab 4 and can be operated by an operator or the like. The control lever 32 sends an instruction on an operation amount of each actuator (11, 12, 13, 14, 15a, 15b) to the controller 27. The monitor 31 is used for setting a work area of the work assistance function, for setting a stop area, a deceleration area, and a notification area of the operation assistance function, and for switching between enabled and disabled states of the operation assistance function. That is, the monitor 31 functions as a switching device for switching between enabled and disabled states of the operation assistance function in the present embodiment. The switch 29 is used to switch between enabled and disabled states of the work assistance function. That is, the switch 29 functions as a switching device for switching between enabled and disabled states of the work assistance function in the present embodiment. The buzzer (notification unit) 28 is used to notify the operator or the like of an obstacle, when detected by the detection device 25, via a sound (notification sound).
As shown in
For example, coordinates of the bucket end P4, which may be a target point to be controlled by the work assistance function with respect to the body position P0, can be obtained by trigonometric functions based on the distance L0 from the body position P0 to the boom pin P1, the angle θ0 defined by the body position P0 and the boom pin P1, the body longitudinal inclination θ4, the boom length L1, the boom angle θ1, the arm length L2, the arm angle θ2, the bucket length L3, and the bucket angle θ3.
In addition, coordinates of other control points, for example, the pin P5 on the rod side of the arm cylinder 12, can be obtained by trigonometric functions based on the distance L5 from the arm pin P2 to the pin P5 on the rod side of the arm cylinder 12, and the angle θ5 defined by the direction from the boom pin P1 to the arm pin P2 and the direction from the arm pin P2 to the pin P5 on the rod side of the arm cylinder 12, in addition to the aforementioned dimensions.
The above-described angle information of the hydraulic excavator 1, including the body longitudinal inclination θ4, the boom angle θ1, the arm angle θ2, the bucket angle θ3, and the like, can be obtained based on the information from the body inclination sensor 18, the boom inclination sensor 19, the arm inclination sensor 20, and the bucket inclination sensor 21, for example.
For example, coordinates of the bucket end (claw top position) P4 in the body coordinates can be obtained by trigonometric functions based on the distance L from the body position P0 to the bucket end P4 and the turning angle θsw. The distance L from the body position P0 to the bucket end P4 can be calculated by trigonometric functions using the above-described attitude information of the hydraulic excavator 1. The turning angle θsw can be obtained based on the information from the turning angle sensor 22, for example.
In this way, the information (specifically, the control point positional information) obtained from the attitude sensor 30 including the turning angle sensor 22, the GNSS antennas (23, 24), and the inclination sensors (18, 19, 20, 21) is input to the controller 27 as the attitude information of the body.
(Operation Assistance Function)
With reference to
An area 39 enclosed by dotted lines is a deceleration area. When an object is detected in this area 39, the operation of the hydraulic excavator 1 is decelerated, and a notification sound is emitted from the buzzer 28.
An area 40 enclosed by diagonal lines is a stop area. When an object is detected in this area 40, the operation of the hydraulic excavator 1 is stopped, and a notification sound is emitted from the buzzer 28.
In the example shown in
The areas of the operation assistance function are fixed with respect to the coordinates P0 of the traveling body 2, and will not move even through the turning operation of the hydraulic excavator 1. In the traveling operation of the hydraulic excavator 1, the areas of the operation assistance function simultaneously move along with the movement of the hydraulic excavator 1. It should be noted that the areas of the operation assistance function may be defined with respect to the global coordinates. In this case, the areas of the operation assistance function will not move even through the traveling operation of the hydraulic excavator 1.
The deceleration factor calculation unit 41 calculates a deceleration factor based on the detection information from the detection device 25 and the operation assistance area information set on the monitor 31 (setting information on each area of the operation assistance function) (see
With such a configuration, the operation assistance function of the controller 27 can control each actuator so as to decelerate or stop the operation of the hydraulic excavator 1 when an object is detected in each area of the operation assistance function set in advance based on the detection information from the detection device 25.
If a determination result of step S103 is Yes, the process proceeds to step S106, where it is determined whether a detected object is in a stop area. If a determination result of step S106 is No, the process proceeds to step S107, where a deceleration factor of an actuator is calculated according to the position of the detected object. Next, in step S108, it is determined whether the operation assistance function is in an enabled state based on an output from the monitor 31. If a determination result of step S108 is No, the process proceeds to step S109, where the required speed of the actuator is directly set as the speed limit of the actuator, and a control instruction is output to the solenoid proportional pressure reducing valve corresponding to the actuator and the process ends. That is, in step S109, the operation assistance function directly ends. If a determination result of step S108 is Yes, the process proceeds to step S110, where a speed limit of the actuator is calculated based on the deceleration factor of the actuator and the required speed of the actuator, and a control instruction is output to the solenoid proportional pressure reducing valve corresponding to the actuator. Next, in step S111, a notification sound is output from the buzzer 28 at a notification sound level (
If a determination result of step S106 is Yes, the process proceeds to step S112, where a deceleration factor (0 herein) of the actuator is calculated. Next, in step S113, it is determined whether the operation assistance function is in an enabled state based on an output from the monitor 31. If a determination result of step S113 is No, the process proceeds to step S114, where the required speed of the actuator is directly set as the speed limit of the actuator, and a control instruction is output to the solenoid proportional pressure reducing valve corresponding to the actuator and the process ends. That is, in step S114, the operation assistance function directly ends. If a determination result of step S113 is Yes, the process proceeds to step S115, where a speed limit of the actuator is calculated based on the deceleration factor of the actuator and the required speed of the actuator, and a control instruction is output to the solenoid proportional pressure reducing valve corresponding to the actuator. Finally, the process proceeds to S116, where a notification sound is output from the buzzer 28 at a notification sound level (
(Work Assistance Function)
With reference to
It should be noted that the shape of the work area of the work assistance function need not be a rectangle, and any shape can be set. In addition, a method for setting a work area of the work assistance function is not limited to the illustrated example.
It should be noted that the control point of the work machine used for controlling the actuator may be set in advance by an operator or the like, or may be set through the calculation by the controller 27 based on the attitude information of the hydraulic excavator 1 or the like. Examples of the control point may include the rear end of the turning body 3, the back face of the bucket 10, the end of the entire hydraulic excavator 1 that can be calculated by the controller 27, or the like, in addition to the above-described points.
The required speed calculation unit 42 calculates a required speed of each actuator based on an operation signal (operation amount) received from the control lever 32. The distance calculation unit 52 calculates a distance between a control point and an outer edge of the work area based on the control point positional information obtained from the attitude sensor 30, the work area information (setting information on the work area) set on the monitor 31, and the required speed received from the required speed calculation unit 42. Herein, the required speed is used to obtain a moving direction of the control point, and the distance to the outer edge of the work area in the moving direction of the control point is calculated. The deceleration factor calculation unit 41 calculates a deceleration factor of the actuator based on the distance received from the distance calculation unit 52 (see
With such a configuration, the work assistance function of the controller 27 can control each actuator so as to prevent the control point of the hydraulic excavator 1 from going out of the work area of the work assistance function set in advance based on the attitude information (control point positional information) of the hydraulic excavator 1.
(Characteristic Configuration of Operation Assistance Function According to First Embodiment)
With reference to
When the work assistance function is in an enabled state via the switch 29 and the work area 51 is set via the monitor 31, the stop area 40 will be extended from the area shown in the left illustration to the diagonally-lined area shown in the right illustration, and will be set to be overlaid on the work area 51. In other words, the work area 51 set via the monitor 31 will be set as the stop area 40. Specifically, in other words, the stop area 40 will be set (extended) so as to match with the work area 51 set via the monitor 31. At this time, when the operation assistance function is in a disabled state, the operation assistance function will be (automatically) enabled so as to enable the stop area 40 of the operation assistance function, and as described above, the stop area 40 will be set to be overlaid on the work area 51, that is, the work area 51 will be set as the stop area 40. In addition, when the notification area 38 and the deceleration area 39 of the operation assistance function are set, they will further be set outside of the stop area 40 set (extended) as described above.
The work area determination unit 53 sets a work area based on a work area input set on the monitor 31 and a work assistance enabled/disabled state input that is the input information of the switch 29. When the work assistance function is in an enabled state, the work area determination unit 53 outputs the work area input set on the monitor 31 as work area information. The operation assistance enabled/disabled state determination unit 54 switches between enabled and disabled states of the operation assistance function based on an operation assistance enabled/disabled state input (enabled or disabled setting of the operation assistance function) set on the monitor 31 and the work area information received from the work area determination unit 53. Specifically, even when the operation assistance function is set in a disabled state, when there is an output from the work area determination unit 53, the operation assistance enabled/disabled state determination unit 54 enables the operation assistance function and outputs the setting of the operation assistance function. When there is no output from the work area determination unit 53, the operation assistance enabled/disabled state determination unit 54 directly outputs the setting of the operation assistance function set on the monitor 31. The operation assistance area determination unit 55 calculates and outputs each area of the operation assistance function based on the operation assistance area input (setting information on each area of the operation assistance function) received from the monitor 31, the work area information received from the work area determination unit 53, and the operation assistance enabled/disabled state received from the operation assistance enabled/disabled state determination unit 54 as described with reference to
The operation assistance area information received from the operation assistance area determination unit 55 and the operation assistance enabled/disabled state received from the operation assistance enabled/disabled state determination unit 54 are used for the calculation process of the operation assistance function as described with reference to
It should be noted that in the above-described embodiment, when the operation assistance function can be switched between enabled and disabled states by the monitor 31, which serves as a switching device for switching between enabled and disabled states of the operation assistance function, and the work assistance function can be switched between enabled and disabled states by the switch 29, which serves as a switching device for switching between enabled and disabled states of the work assistance function, and when the work assistance function is in an enabled state and the work area 51 is set, the controller 27 (or the operation assistance function thereof) enables the operation assistance function (even when the operation assistance function is in the disabled state) and sets the work area 51 as the stop area 40.
However, when the work assistance function cannot be switched between enabled and disabled states, for example, when the work area 51 is set, the controller 27 (or the operation assistance function thereof) may enable the operation assistance function (even when the operation assistance function is in the disabled state) and set the work area 51 as the stop area 40. In addition, when both of the operation assistance function and the work assistance function cannot be switched between enabled and disabled states, for example, when the work area 51 is set, the controller 27 (or the operation assistance function thereof) may set the work area 51 as the stop area 40.
As described above, in the first embodiment, the operation assistance system for a work machine has the operation assistance function of stopping the hydraulic excavator (work machine) 1 when an object is detected in the stop area 40 set in advance based on the detection information from the detection device 25 that detects an object around the hydraulic excavator (work machine) 1 with the work implement 7 and the work assistance function of preventing the hydraulic excavator (work machine) 1 from going out of the work area 51 set in advance based on the attitude information of the hydraulic excavator (work machine) 1. When both of the operation assistance function and the work assistance function can be switched between enabled and disabled states, and when the work assistance function is in an enabled state and the work area 51 is set, the operation assistance system enables the operation assistance function and sets the work area 51 as the stop area 40.
In addition, when the deceleration area 39 is set outside of the stop area 40 and an object is detected in the deceleration area 39 based on the detection information from the detection device 25, the operation assistance system decelerates the hydraulic excavator (work machine) 1.
In addition, when the notification area 38 is set outside of the stop area 40 and an object is detected in the notification area 38 based on the detection information from the detection device 25, the operation assistance system makes a notification from the buzzer (notification unit) 28 provided in the operation assistance system.
According to the first embodiment, when the work area 51 is set, the operation assistance system sets the work area 51 as the stop area 40. Thus, in the operation assistance system for a work machine having both operation assistance and work assistance functions, it is possible to reduce the inconvenience to an operator or the like of setting an area of the operation assistance function and an area of the work assistance function (in particular, an area of the operation assistance function), and prevent a collision of the work machine with an object in a work area.
For example, as a variation of the configuration of the hydraulic excavator of the first embodiment, the hydraulic excavator 1 may receive, via communication with a server 56, positional information (detection information) of a worker 59 around the body as an output from a detection device 58 disposed outside of the body. In addition, the hydraulic excavator 1 may receive, via communication with the server 56, positional information and attitude information of the hydraulic excavator 1 as an output from a detection device (not shown) disposed outside of the body. In addition, an enabled or disabled state of the work assistance function of the hydraulic excavator 1 may be set from the outside of the body via the server 56, not via the switch 29. In addition, a work area of the work assistance function or areas of the operation assistance function of the hydraulic excavator 1, or an enabled or disabled state of the operation assistance function of the hydraulic excavator 1 may be set from the outside of the body via the server 56, not via the monitor 31. In addition, the hydraulic excavator 1 may be remotely operated from the outside of the body (control tower or cockpit) via the server 56, not via the control lever 32 disposed inside of the cab 4. In addition, the server 56 may calculate a notification instruction and a control instruction of the solenoid proportional pressure reducing valve and the like based on the work area of the work assistance function or the areas of the operation assistance function and the detection information of the object, and transmit them to the hydraulic excavator 1. In addition, when a worker 59 or a dump truck 60 is detected in the notification area 38, a notification of its entry into the notification area 38 may be made from a notification unit (not shown) worn by the worker 59, a notification unit 57 disposed at the site, or a notification unit (not shown) in the dump truck 60. In addition, the hydraulic excavator 1 may directly communicate with the detection device 58 or other devices, not via the server 56.
According to the second embodiment, as in the first embodiment, in the operation assistance system for a work machine having both operation assistance and work assistance functions, it is possible to reduce the inconvenience to an operator or the like of setting an area of the operation assistance function and an area of the work assistance function (in particular, an area of the operation assistance function), and prevent a collision of the work machine with an object in a work area.
In addition, when an area including the outside of the detectable range 62 of the detection device 58 is set as the work area 51, the operation assistance system sets as the work area 51 an area simultaneously satisfying both of the detectable range 62 and the area set as the work area 51. This allows appropriate setting of the work area 51 and the stop area 40.
It should be noted that the present invention is not limited to the aforementioned embodiments, and includes various modifications. Although the aforementioned embodiments have been described in detail to clearly illustrate the present invention, the present invention need not include all of the configurations described in the embodiments.
In addition, some or all of the aforementioned functions of the controller of the embodiments may be implemented as hardware by designing them as an integrated circuit, for example. Alternatively, the aforementioned functions of the controller of the embodiments may be implemented as software through analysis and execution of a program that implements each function by a processor. Information such as the program that implements each function, tables, and files can be stored in a storage device such as a hard disk, or a SSD (Solid State Drive); or a storage medium such as an IC card, an SD card, or a DVD, in addition to a storage device in the controller.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2020/013437 | 3/25/2020 | WO |
