JPH0937610A - Operation of unmanned mower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently mow a ground with an autonomously travelable mower. SOLUTION: An automatic mower 1 has wheels, a driving system, and internal sensors such as an optical fiber gyrocompass and a vehicle speed sensor, and can autonomously travel. The mowing unit in the mower 1 can mow on either of forward and backward travels. The mower 1 mows the first mowing region P1 in the forward direction and subsequently mows the adjacent region P2 in the backward direction. The mower is steered only in the approximately same distances in the left and right directions for the lateral movement of the mower only in a mowing distance C1 , thus enabling to cancel the accumulated error of the optical fiber gyrocompass for the achievement of a correct operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic mobile work machine equipped with an autonomous navigation system having various sensors, and more particularly to an operating system for an automatic lawnmower.

[0002]

2. Description of the Related Art By mounting an autonomous navigation device having an angle sensor, a vehicle speed sensor, etc. on a lawnmower capable of automatic traveling, unmanned automatic driving and lawnmower work can be performed.

[0003]

The autonomous navigation system requires a sensor such as an optical fiber gyro for detecting the turning of the vehicle and a vehicle speed sensor for measuring the moving amount of the vehicle, and detects an obstacle or the like. It is also necessary to provide a sensor that activates the vehicle and a sensor that performs an emergency stop when the vehicle comes into contact with an obstacle. Using the information of these sensors, the vehicle can travel to the destination along the route given beforehand based on the map information given beforehand.

However, in this autonomous navigation system, it is necessary to accurately position the vehicle at the start position of the movement route and to accurately match the direction of the vehicle at the start. Further, since the autonomous navigation device travels while estimating the current position by accumulating the movement amount of the vehicle from the start position and the change in the steering angle, the error of the vehicle speed sensor and the error of the angle sensor are accumulated and the map is displayed. There is an error between the scheduled current position of the vehicle and the actual current position of the vehicle. In particular, the optical gyro used as a sensor for detecting the direction of the lawnmower has a characteristic that errors in angle detection are accumulated when the lawnmower is steered in the same turning direction.

The present invention provides an operation control system for a lawnmower equipped with an autonomous navigation system and having high accuracy in the working direction.

[0006]

An unmanned lawn mower to which the present invention is applied includes a lawn mowing unit capable of performing lawn mowing in either forward or backward traveling directions. The optical fiber gyroscope, which detects the traveling direction of the vehicle, accumulates errors when turning continues only in one direction, but has high accuracy when turning is made by the same amount alternately in the left and right directions. The operation system of the present invention achieves efficient lawn mowing in consideration of the above characteristics.

[0007]

This mobile work machine is provided with an autonomous navigation device and a radio navigation device. Therefore, under conditions where the radio navigation device cannot be used, autonomous operation is performed by autonomous navigation, and when the radio navigation device is available, Correct the current location by autonomous navigation to achieve more accurate autonomous driving.

[0008]

1 is a plan view of a mobile work machine according to the present invention, and FIG.
Is a side view. The mobile work machine, generally designated by reference numeral 1,
Mobile work machine 10 and body 1 mounted on main body 10
2 The mobile work machine body 10 is, for example, a lawn mower, and includes a main frame 20 and a main frame 20.
It has two front wheels 22 and one rear wheel 24 for supporting.
At the bottom of the frame 20, the grass cutting unit 7
0 is provided, and an engine 30 is provided above the frame 20. The engine drives the hydraulic pump 40, and the pressure oil generated by the hydraulic pump 40 drives and steers the wheels, raises and lowers the lawn mowing unit, and drives the cutter.

On both sides of the frame 20, a fuel tank 32,
A hydraulic pump tank 34 and the like for the hydraulic pump are provided. A seat 50 for an operator and a steering wheel 60 are arranged on the frame 20. When manned driving, the body 12 is opened and the operator gets on and operates. Around the seat 50, operation levers 80 and 82 for manned driving are arranged.

The lawn mowing unit 70 includes a housing 71.
And a grass box 72 connected to the housing 71.
Cutter blade 73 arranged in the housing 71
Is rotatably driven by an actuator (not shown), and the cut grass is stored in the grass box 72. The lawn mowing unit 70 can perform lawn mowing regardless of whether the lawnmower 1 moves forward or backward.

In principle, the mobile work machine 1 is a machine that moves and works by unmanned operation, and is equipped with a controller 200 for that purpose. In addition, the mobile work machine 1 may be equipped with a GPS device for grasping its own position, and a communication device for receiving data from a fixed station in order to improve position detection.

FIG. 4 is a block diagram showing the system configuration of the mobile work machine. A mechanism for driving and operating the mobile work machine includes a hydraulic pump 100 driven by an engine 30, and pressure oil sent from the hydraulic pump controls the steering angle of the steered wheels 24 via an operating cylinder 110. The steering control device 120 has a steering control mechanism 124 driven by a steering control actuator, and the control amount is detected by each steering sensor 126. When manned, the steering wheel 50 is manually operated.

The pressure oil is sent to the hydraulic motor 130 and drives all the wheels 22, 24. The travel control device 140 has a drive control mechanism 144 driven by a travel control actuator 142, and the control amount is controlled by a travel control angle sensor 146.
Detected in. Specifically, the angle of the accelerator opening is controlled,
To be detected. During manned operation, the accelerator pedal 90 is manually operated.

A hydraulic motor 150 driven by pressure oil drives the cutters of the cutter units 70 and 72. The cutter drive control device 160 has a drive control mechanism 164 driven by a cutter drive actuator 162, and the control amount is detected by an operation confirmation sensor 166. During manned operation, it is manually operated by the operation lever 80. The hydraulic cylinder 170 driven by pressure oil moves the lawn mowing unit 70 up and down, and the cutter up-and-down controller 180 moves up and down.
It has a drive control mechanism 184 driven by a cutter drive actuator 182, and the control amount is the operation confirmation sensor 1
Detected at 86. During manned operation, it is manually operated by the operation lever 80.

The controller 200 includes map information means 21.
0, work path generating means 220, trajectory target value means 230,
Position estimation means 240, error correction means 250, target speed /
The direction calculation means 260 is provided. The output of the target speed / direction calculation means 260 is sent to the control device of each device via the operation command means. The engine is started via the engine control device 310 by the main switch of the switch box 330. The bumper switch 320 provided on the bumper of the vehicle body frame 20 detects that the vehicle body has contacted an obstacle, stops the engine, and executes an emergency stop.

The mobile work machine has various sensors for performing unmanned movement and work. The obstacle recognition sensor 340 detects surrounding obstacles using ultrasonic waves or the like.
The internal sensor 400 equipped on the mobile work machine includes a geomagnetic sensor 410, an optical fiber gyro 420, and a vehicle speed sensor 4.
30 to detect the traveling direction and movement amount of the machine. The steering angle sensor 126 detects the steering angle, and the traveling control sensor 1
46 detects the accelerator angle. The mobile work machine 1 can perform automatic running and work by unmanned operation based on the information from these sensors and the map information provided in the controller.

The mobile work machine 1 has a GPS sensor 500 in addition to the internal sensors 400. This G
The PS sensor 500 can receive a radio wave from a GPS satellite and calculate a current position. Further, it has a device 510 for receiving GPS data from a fixed station installed near the work area, and the controller 200 receives this data via the communication interface 520. This GP
By providing the S system, the mobile work machine can accurately recognize its current position.

FIG. 5 shows a state in which the lawnmower 1 mows the lawn M in the area G between the lines F ₁ and F ₂ which is the work target area. The lawn mowing area G is a flat field such as a soccer ground, and lawn mowing is performed on the lawn mowing work area as indicated by loci P ₁ and P ₂ . A good soccer ground can be formed by overlapping the lawn mowing trajectories P ₁ and P ₂ in the width direction. The width dimension D of the lawn mowing path is determined by the cutter blade 73.
Match the diameter dimension of. Therefore, the overlap amount can be adjusted by controlling the moving distance C _{1 in the} direction orthogonal to the traveling direction of the lawnmower 1.

FIG. 6 is a plan view showing an example of a lawnmower control method according to the present invention. The lawn mower 1 has an operation starting point S
_{In 1} , the direction is set to face N. The lawnmower 1 to which the operation command has been given starts acceleration from a stationary state and progresses toward the work start point P ₁ at a speed V ₁ .

[0020] is set on the work area F ₁ work start point P ₁
When it reaches, the lawnmower 1 lowers the lawn mowing unit 70 and starts lawn mowing while traveling in the forward direction FD. The lawnmower proceeds in the direction N direction at the working speed V ₂ and executes lawn mowing. Upon reaching the point P ₂ on the other in the work area F ₂ of the ground G, and stops the operation of the mowing unit 70, and shifting the speed V ₃ is switched to the transition speed V _11, performs rightward steering and leftward steering point Reach P ₃ and stop. In this state, the lawnmower moves in the direction E by the distance C ₁ . At this time, the angles of right steering and left steering are equalized, so that the optical gyro error is canceled and accurate angle measurement can be performed.

Next, the lawn mower starts to accelerate in the reverse direction RD, travels a distance L ₁ at a speed V ₁ , and reaches a point P ₄ .
At the point P ₄ , the lawn mowing unit is operated to perform lawn mowing while moving backward at the working speed V ₂ . When the point P ₅ is reached, the operation of the lawn mowing unit is stopped and the direction is maintained as it is.
Travel for distance L ₂ and stop at point P ₆ .

Next, the lawn mower starts traveling in the forward direction FD, shifts to speed V ₃ at speed V ₁₂ , performs right steering and then left steering, and reaches point P ₇ . Since the steering angles of the right steering and the left steering are equal in opposite directions, the error of the optical gyro is canceled and a highly accurate turning can be achieved.
The lawnmower unit is operated at the point P ₇ , the work speed is changed to the working speed V ₂ at the speed V ₁₃ , and the bearing N is maintained to move to the point P ₈ . At this time, the moving path of the lawnmower is separated from the immediately preceding moving path by a distance C _{1 in the} direction E.

The operation of the lawnmower unit is stopped at the point P ₈ , the operation proceeds to the point P _{9, and} then stopped. This process is the same as the process from the point P ₂ to the point P ₃ described above. The lawn mower starts moving backward from the point P ₉ and travels a distance L ₁ to start the lawn mowing from the point P ₁₀ . The lawn mowing is executed while moving backward at the speed V ₂ , and the operation of the lawn mowing unit is stopped at the point P ₁₁ . Hereinafter, the same traveling pattern is repeated. In the traveling pattern described above, the lawnmower is steered only when moving forward.

FIG. 7 shows another example of the traveling pattern. Even in this running pattern, the lawn mower starts traveling forward from the operation start point S _{1 in the} direction N, operates the lawn mower unit from the work start point P ₁ , and moves to the point P ₂ of the lawn mower unit. The operation is stopped, and right steering and left steering are executed while proceeding to the point P ₂ . Starting backward movement from the point P _{3 in the} direction S direction, stopping the operation of the lawnmower unit from the point P ₄ to the point P ₅ , and performing rightward steering and leftward steering in the reverse state while proceeding to the point P _6. . The forward movement is started from the point P ₆ toward the bearing N, and the lawn mowing is executed from the point P ₇ .

In this running pattern, the number of types of transition speeds is small, and operation control becomes easy. Further, since the approach section by going straight ahead can be provided immediately before the lawn mowing work, more uniform lawn mowing can be achieved.

[0026]

As described above, the present invention can improve the workability of lawn mowing work by efficiently operating an unmanned lawnmower.

[Brief description of drawings]

FIG. 1 is a plan view of an unmanned lawn mower to which the present invention is applied.

FIG. 2 is a side view of an unmanned lawn mower to which the present invention is applied.

FIG. 3 is a view taken in the direction of arrow A in FIG. 2;

FIG. 4 is a block diagram of control of an unmanned lawn mower.

FIG. 5 is an explanatory view showing a working method of the lawnmower.

FIG. 6 is an explanatory view showing an operation method of the lawnmower.

FIG. 7 is an explanatory diagram showing an operating method of the lawn mower.

[Explanation of symbols]

 1 Lawn Mower 10 Vehicle Main Body 22 Front Wheel 24 Rear Wheel 70 Lawn Mowing Unit 73 Cutter Blade 200 Controller 400 Internal Sensor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuji Matsuda 7-1-1 Higashi Narashino, Narashino City, Chiba Prefecture Hitachi Industrial Co., Ltd. Industrial Equipment Division (72) Inventor Noriyuki Kamiya 7-1 Higashi Narashino, Narashino City, Chiba Prefecture Issue Hitachi Industrial Co., Ltd. Industrial Equipment Division (72) Inventor Toshihiro Aono 502 Jinritsucho, Tsuchiura-shi, Ibaraki Prefecture Hiritsu Manufacturing Co., Ltd. Mechanical Research Laboratory (72) Inventor Masami Otomo 7-1-1 Higashi Narashino, Narashino, Chiba Issue Hitachi Keiyo Engineering Co., Ltd. (72) Inventor Kenji Seino 7-1 Higashi Narashino, Narashino City, Chiba Prefecture Hitachi Keiyo Engineering Co., Ltd. (72) Inventor Kazuo Kobayashi 4-6 Kanda Surugadai, Chiyoda-ku, Tokyo Hitachi Industrial Equipment Division

Claims (2)

[Claims] 1. A vehicle having drive wheels and steered wheels, a lawn mowing unit mounted on the vehicle, an engine mounted on the vehicle, means for driving each wheel and the lawn mowing unit by the power of the engine, and a vehicle. It has an on-board controller and an autonomous navigation device that automatically drives the vehicle based on map information and information from internal sensors including the optical fiber gyro and vehicle speed sensor installed in the vehicle. From the point to the end point of work, go straight while moving forward in the first work area, and the vehicle with the operation of the lawn mowing unit stopped at the end point of work travels while steering the same amount in the left-right direction. And a step of moving the vehicle laterally by the cutting width and stopping, and a step of mowing the second work area adjacent to the first work area while the vehicle goes straight in the reverse direction. At the end of the work, the vehicle that stopped the operation of the lawn mowing unit goes straight forward for a certain distance and then stops. An operation method of an unmanned lawn mower, comprising: a step of moving laterally to a work start point of a third work area adjacent to the second work area. 2. A vehicle having drive wheels and steered wheels, a lawn mowing unit mounted on the vehicle, an engine mounted on the vehicle, means for driving each wheel and the lawn mowing unit by the power of the engine, and a vehicle It has an on-board controller and an autonomous navigation device that automatically drives the vehicle based on map information and information from internal sensors including the optical fiber gyro and vehicle speed sensor installed in the vehicle. From the point to the end point of work, go straight while moving forward in the first work area, and the vehicle with the operation of the lawn mowing unit stopped at the end point of work travels while steering the same amount in the left-right direction. And a step of moving the vehicle laterally by the cutting width and stopping, and a step of mowing the second work area adjacent to the first work area while the vehicle goes straight in the reverse direction. At the end of the work, the vehicle that stopped the operation of the lawnmower unit travels while steering in the left-right direction with almost the same amount of movement, moves the vehicle laterally by the cutting width and stops, and the vehicle moves forward. And a process of moving to a work start point of a third work area adjacent to the second work area.