JPH08255018A - Position error correcting device for automatic traveling vehicle - Google Patents

Abstract

PURPOSE: To provide the device which corrects the current position of own vehicle with a signal sent from a reference position on the ground for the vehicle which recognizes the current position by various sensors and can automatically travel. CONSTITUTION: A lawn mower 1 as the traveling vehicle is equipped with a geomagnetic sensor, a speed sensor, a GPS sensor, an optical fiber gyro, a controller, etc., and mows a lawn along a target track P1 in a lawn mowed area E1 such as a soccer ground where an unmanned self-travel is possible. An error correcting device 1000 installed in the field irradiates an error correcting device L1 with laser light. A photodetecting element provided on the vehicle 1 sends a photodetection signal to the controller to correct an error in the position of the vehicle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an autonomous vehicle such as a work vehicle capable of unmanned driving.

[0002]

2. Description of the Related Art For example, a riding type lawnmower has a driving seat, an engine, an operating device, etc. on a frame, controls steering and driving of wheels, and is a power driven cutting unit. To cut the lawn. By mounting an automatic control device on this type of traveling vehicle, unmanned autonomous driving is possible.

[0003]

In this type of automatic traveling vehicle, it is necessary to equip a sensor for detecting the present position, traveling direction, traveling speed, etc. of the vehicle. As the sensor, a sensor such as a geomagnetic sensor, an acceleration sensor, a GPS sensor, an optical fiber gyro or the like can be used in addition to the speed sensor that detects the rotation of the wheels. However, an unmanned vehicle may cause an error in the current position of the vehicle detected by the various sensors described above. This error has the property of being accumulated in proportion to the traveling distance of the vehicle. The present invention
The present invention provides a device that corrects the current position of a vehicle during unmanned operation.

[0004]

SUMMARY OF THE INVENTION A position error correction device for an automatic traveling vehicle according to the present invention includes a vehicle frame, an engine mounted on the frame, wheels driven by the power of the engine, and a travel operation device. A control device for controlling the traveling operation device, a body mounted on the vehicle, a light receiving element mounted on a side portion of the body, and means for outputting a signal received by the light receiving element to the control device, It is provided with a unit for receiving a signal input and calculating a correction of the current position of the vehicle, and a unit fixed to the ground for emitting a laser beam toward the vehicle.

[0005]

The automatic vehicle recognizes its own current position by various sensors, but there is an error between the position when receiving light from a fixed position on the ground and the recognized position of the own vehicle. Sometimes, the current position of the vehicle is corrected based on the light receiving position.

[0006]

1 is a plan view of a traveling vehicle showing an embodiment of the present invention, and FIG. 2 is a side view thereof. The traveling vehicle generally denoted by reference numeral 1 has a traveling vehicle body 10 and a body 300 that is exteriorly mounted on the traveling vehicle body 10. The traveling vehicle body 10 is, for example, a self-propelled lawnmower, and the main frame 20 is supported by two front wheels 22 and one rear wheel 24. The engine 30 is mounted on the main frame 20 and the hydraulic pump 2
00 and 250 are driven. In this lawnmower, a fuel tank 34, a battery 32, and the like are arranged in the vicinity of the engine 30, which is hydraulically supplied with power for traveling and driving force of a lawn cutting unit and the like.

A seat 50 for an operator is mounted on the central upper portion of the main frame 20, and a steering device 52 is arranged in front of the seat 50. Around the seat 50, in addition to the manual brake lever 54 and the control switch 80 of the cutting unit, a forward pedal and a reverse pedal (not shown) of the vehicle are arranged. The body 300 mounted on the traveling vehicle body 10 includes a bumper body 310 that surrounds the main frame 20 with a curved surface. An engine cover 320 that covers the periphery of the engine 30 and a front cover 330 that covers the front part of the vehicle body are attached to the upper portion of the bumper body 310. These bodies are made of plastic or the like and are appropriately coated.

For this unmanned operation, various sensors and control devices are mounted. Controller 100 of control device
Are arranged around the seat 50. GP that uses a satellite as a sensor to detect the position and traveling direction of the vehicle
S (Global Positioning System) sensor 12
1 and the geomagnetic sensor 123 are equipped. Before and after the bumper body 310, an object sensor 111 for detecting an obstacle and a contact sensor 113 for stopping the vehicle when touching an obstacle or a person are arranged. A ground sensor 112 for detecting that the vehicle is on the ground is also provided. The traveling position of the vehicle can be detected by using the GPS sensor 121 and the geomagnetic sensor 123. However, in order to more accurately control the work range of lawn mowing and the like, a vehicle speed sensor 140 for contacting the ground and detecting the vehicle speed is provided.

FIG. 3 is an explanatory diagram showing the system configuration of the traveling vehicle of the present invention. The engine 30 drives two hydraulic pumps 200 and 250. First hydraulic pump 200
Is a turf cutting unit and a hydraulic pump for steering operation. The output of the hydraulic pump 200 is sent to the vertical movement cylinder 62 of the front cutting unit 60 and the vertical movement cylinder 72 of the rear cutting unit 70 via the control valve unit 40A to perform the vertical movement of the cutting units 60, 70. . This hydraulic pressure is sent to the hydraulic motors 202 and 204 which drive the cutting units 60 and 70, and rotationally drives the cutting units. This cutting unit 60,
Reference numeral 70 has a fixed blade and a reel blade, and by rotationally driving the reel blade, grass can be sharply cut between the fixed blade and the fixed blade.

The output of the control valve unit 40A is also supplied to the steering hydraulic motor 210. The steering hydraulic motor 210 is connected to the steering 52, and when the steering 52 is operated, the steering hydraulic motor 210 sends hydraulic pressure to the cylinder 212 that steers the rear wheel 24. The steering cylinder 212 steers the rear wheel 24. The second hydraulic pump 250 is a hydraulic pump for transmission, and its output is output via the control valve unit 40B to the hydraulic motor 252 for driving the front wheels 22 and the rear wheels 2.
4 to the driving hydraulic motor 254. By alternately depressing the forward pedal 90 and the reverse pedal 92 provided in the driver's seat, the forward and reverse movements of the vehicle are achieved via the control valve unit 40B. The rear wheel 24 is equipped with a disc brake 25, which is mechanically braked by a manual brake lever 54.

The controller 100 having a board computer receives information from the obstacle recognition sensor 110 mounted on the bumper body 310. The obstacle recognition sensor 110 has a contact sensor 111, a ground sensor 112, and an objective sensor 113. Further, information is also input from sensors such as the geomagnetic sensor 121, the acceleration sensor 122, the GPS sensor 123, and the optical fiber gyro 124 that detect the traveling of the vehicle. Further, the actual position of the vehicle is detected and the error correction signal 126 is also given to the controller 100.

The traveling vehicle 1 can select an unmanned operation mode and a manned operation mode, and has a switch 102 for switching between the operation modes. A door interlock switch 138 is provided to confirm the unmanned operation mode and the manned operation mode. Steering motor 23 for controlling hydraulic motor 210 for steering to achieve unmanned operation
0, the controller 100 sends an output signal to the steering motor 230 according to the information of the steering angle sensor 130. Similarly, an actuator 136 for operating the forward pedal 90 and the reverse pedal 92 is provided, and the depression amount of the pedal is controlled via the accelerator amount detection sensor 134. The ignition switch 36 that starts the engine 30 is
When the contact sensor 111 of the obstacle recognition sensor 110 directly operates and touches an obstacle or a person, the ignition switch 36 is shut off and the operation of the engine 30 is stopped. The rotation speed of the engine 30 is controlled by the throttle lever 37.

1 and 2 show a state in which the traveling vehicle 1 is driven unmanned. Front cover 330 of body 300
Then, the engine cover 320 is closed and the side surface is formed in an oval shape. The planar shape is also a substantially elliptical shape. The front portion 312 of the bumper body 310 is formed in a shape that covers the reel blade of the front cutting unit 60, and prevents foreign matter from being wound into the reel blade. The steering wheel 52 is foldable as necessary and is accommodated during unmanned operation. When driven unattended in this state, the streamlined body has an extremely novel design, making it easy to draw attention. Front cover 330, engine cover 3
20 may be formed of transparent plastic, and may be colored with an appropriate design.

4 and 5 show a state in which the traveling vehicle 1 of the present invention is driven by a manned person. In the vehicle of this embodiment, the engine cover 320 slides backward on the slide rail 380 fixed to the main frame 20 of the traveling vehicle body 10. Since the front cover 330 is fixed to the main frame 20, the space S is formed between the front cover 330 and the front cover 330 by opening the engine cover 320.

On the front cover side of the engine cover 320, a window 350 is openably and closably mounted via a hinge arm 340. The window 350 is held open by the stopper 355. The driver D uses the space S to get in the seat 50, returns the steering wheel 52 to a predetermined position, and drives the traveling vehicle 1. The configuration of the traveling vehicle body 10 is the same as that described with reference to FIGS.

FIG. 6 is a plan view of a traveling vehicle equipped with a driving lamp for displaying the state of the present invention, and FIG. 7 is a side view. The driving lamp 280 for displaying the state is attached to the upper portion of the window 350 in front of the highest portion of the body 300 of the vehicle. The operation lamp 280 is, for example, a horizontally long LED lamp and has 10 lamps. Then, a different display is displayed according to the unmanned driving state of the vehicle.

FIG. 8 is an explanatory diagram showing a position error correcting device for an automatic vehicle according to the present invention. The position error detection device 126 mounted on the vehicle 1 includes a plurality of light receiving elements 126a,
The light receiving element 126a has a correction signal input 126b for detecting and receiving light, and a correction signal holding circuit 126c for holding the correction signal input 126b. The correction signal holding circuit 126c outputs the correction signal output 126e to the controller 10
Output to 0 and a reset signal input terminal 126
d and reset the correction signal.

On the other hand, a portable error compensating apparatus indicated by reference numeral 1000 as a whole is provided with a casing 1020 having a handle 1010, and the casing 1020 comprises a column 1030,
It is placed on the field F by the base 1040.
The error correction device 1000 can be moved to an arbitrary place by the handle 1010. The casing 1020 is equipped with a power supply 1100, a laser driving device 1120, and an issuing element 1130, and emits a laser beam 1150. Position error detection device 1 equipped in the lawn mower 1
The light receiving element 126a of No. 26 outputs the correction signal 126e when receiving the laser beam 1050.

FIG. 9 is a plan view for explaining the mechanism for correcting the position error of the automatic lawnmower 1 according to the present invention. The automatic lawnmower 1 uses the geomagnetic sensor 12 as described above.
1, it is equipped with an acceleration sensor 122, a GPS sensor 123, an optical fiber gyro 124, and the like, and can run by itself. A case will be described in which, for example, a soccer field SG is formed as the lawn mowing target area E _{1 in} the field F of the lawn, and the lawn in the soccer field SG is cut by unmanned driving.

The soccer ground SG is a rectangular ground defined by side lines SL and end lines EL, and a center line CL is defined in the center.
The automatic lawnmower 1 sets a target locus P ₁ on the soccer ground SG, and executes lawn mowing while traveling independently along the target locus P ₁ . Now, it is assumed that the automatic lawnmower 1 has completed lawn mowing on the soccer field SG along the locus P ₂ and has reached the center line CL. The error correction position L ₁ is set on the center line CL,
The error correction device 1000 irradiates the center line CL with the laser beam 1150.

The lawnmower 1 naturally describes that its own position has reached the center line CL by self-sustaining running. Therefore, when attached to the lawnmower 1,
When the position error detection device 126 receives the laser beam 1150, if the center line CL positions recognized by itself match, there is no position error due to self-sustained travel. However, if there is a deviation in this timing, an error occurs in the position recognition of self-sustained travel, so correction is made to cancel this error. With this correction, the automatic lawnmower learns the error occurrence and the correction amount. Therefore, it is not necessary to frequently correct this position error.

In the present invention, the light-receiving element is attached only to one side of the vehicle body of the automatic lawnmower 1 to simplify the apparatus. Further, the laser light 1150 emitted from the light emitting element 1130 expands as it goes far away. Therefore, it is desirable to execute the error correction process when the error correction device 1000 and the automatic lawnmower 1 are as close to each other as possible. Since the error correction device 1000 of the present invention is portable, the lawn mowing target area E ₁ on the field F is
It can be installed in the vicinity of, and the error correction with good system can be achieved. In addition, the pattern of error correction is used for the automatic lawn mower 1
After learning, even if the error correction device 1000 is removed, the automatic lawnmower 1 can run by itself with less position error.

FIG. 10 is a flow chart of the position error correction processing. When the process of error correction by a signal from the outside starts in step S10, the error correction signal is reset in step S11. If the automatic operation by the self-contained navigation is being performed in step S12, the automatic operation control is confirmed in step S13, and the presence or absence of the error correction signal input is detected in step S14. When the error correction signal is caught and there is an error between the position based on the self-contained navigation and the accumulated error due to the past navigation is canceled, step S
This error correction signal is reset by 16.

[0024]

The traveling vehicle of the present invention is equipped with a geomagnetic sensor, an acceleration sensor, a GPS sensor, an optical fiber gyro, and the like, and is capable of autonomous traveling. However, the current position of the vehicle calculated based on the signals of the various sensors described above may cause an error due to the traveling of the vehicle. This position error has the property of being accumulated in proportion to the traveling distance. In the present invention, the light emitting device is arranged at the reference position set on the ground, the light receiving device is provided on the vehicle side, and the signal when the light is received is sent to the control device. The control device corrects the current position of the own vehicle by the reference position that received this light.
The cause of the vehicle position error varies depending on driving conditions and the like and is not constant. The traveling vehicle passes through the reference position a plurality of times and executes the position correction process, thereby learning the tendency of the position error and omitting the subsequent correction.

[Brief description of drawings]

FIG. 1 is a plan view showing an unmanned operation state according to a first embodiment of the present invention.

FIG. 2 is a side view showing the unmanned operation state of the first embodiment of the present invention.

FIG. 3 is an explanatory diagram showing a system of a traveling vehicle.

FIG. 4 is a plan view showing a manned driving state according to the first embodiment of the present invention.

FIG. 5 is a side view showing a manned driving state according to the first embodiment of this invention.

FIG. 6 is a plan view of a vehicle including the light receiving element of the present invention.

FIG. 7 is a side view of a vehicle including the light receiving element of the present invention.

FIG. 8 is an explanatory diagram showing a configuration of a position error correction device.

FIG. 9 is a plan view showing the configuration of a position error correction device.

FIG. 10 is a flowchart of a position error correction process.

[Explanation of symbols]

 1 traveling vehicle 10 traveling vehicle main body 20 main frame 22, 24 wheels 30 engine 40 control valve unit 50 seat 52 steering 60, 70 cutting unit 100 controller 111 contact sensor 112 ground sensor 113 objective sensor 121 geomagnetic sensor 122 acceleration sensor 123 GPS sensor 124 Optical fiber gyro 126 Light receiving element 280 Operating status display lamp 300 Body 350 Window 1000 Portable error correction device 1150 Laser light

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kenjiro Fujii Inventor Kenjiro 4-6 Kanda Surugadai, Chiyoda-ku, Tokyo Inside the Industrial Equipment Division, Hitachi, Ltd. (72) Toshihiro Aono 502 Kintachi-cho, Tsuchiura-shi, Ibaraki Japan Co., Ltd. In the Tate Seisakusho Mechanical Research Laboratory (72) Inventor Tokuhisa Miyake 502 Kintate-cho, Tsuchiura City, Ibaraki Prefecture Inside the Nitate Seisakusho Research Laboratory (72) Inventor Masami Otomo 7-11 Higashi Narashino, Narashino City, Chiba Hitachi Keiyo Engineering Co., Ltd. Co., Ltd. (72) Inventor Kazuo Kobayashi 4-6, Surugadai Kanda, Chiyoda-ku, Tokyo Inside Industrial Equipment Division, Hitachi, Ltd.

Claims (1)

[Claims] 1. A frame of a vehicle, an engine mounted on the frame, wheels driven by the power of the engine, a traveling operating device, a control device for controlling the traveling operating device, and a side portion of a body. Light-receiving element equipped, means for outputting the signal received by the light-receiving element to the control device, means for calculating the correction of the current position of the vehicle in response to the input of the signal, and being fixed to the ground Position error correction device for an autonomous vehicle, which comprises a means for emitting laser light.