JPH07147804A - Unit for preventing deviation of autonomously traveling working vehicle from working area - Google Patents

Abstract

PURPOSE:To improve a working efficiency of an autonomously traveling working vehicle, by reliably preventing a deviation of the vehicle out of a working area and making its high speed traveling possible in the working area. CONSTITUTION:When a lawn mowing working vehicle arrives at an end point of a working route and passes through a space between a projector and a receptor, the light is blocked and ON-OFF signal is generated and transmitted to a photoelectric sensor information receiver 55. When receiving an ON-OFF signal from the receptor 42, the photoelectric sensor information receiver 55 outputs it to a traveling control unit 56 by obtaining an information at the end point location on the line of working route to make the lawn mowing working vehicle turn its direction for preventing a deviation to the outside of a working area. In this way, a high speed traveling of the vehicle in the working area becomes possible to improve a working efficiency markedly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work area deviation preventing device for an autonomous traveling work vehicle which prevents the autonomous traveling work vehicle from departing from the work area.

[0002]

2. Description of the Related Art Generally, in an autonomous vehicle which performs unmanned work such as grass cutting and lawn cutting in various fields such as golf courses, river banks, parks, etc., the technology for measuring the self-position is important for autonomous driving. As a technique for measuring this self-position, there is a conventional technique disclosed in JP-A-63-2476.
As disclosed in Japanese Unexamined Patent Publication No. 12 and the like, a technique of receiving a radio wave transmitted from a positioning satellite to measure its own position, and as disclosed in Japanese Laid-Open Patent Publication No. 2-132321, There is a dead reckoning technology that estimates the position of a vehicle from the direction of travel.

However, in the former technique, due to the error of the clocks of the satellite and the receiver, the error of the orbit of the satellite, the delay of the radio wave due to the ionosphere, the delay of the radio wave due to the atmosphere, multipath, etc., unmanned in a relatively narrow area. Positioning accuracy is insufficient for moving autonomous work vehicles, and with the latter technology,
Errors accumulate in proportion to the distance traveled.

Therefore, in the autonomous work vehicle, the previous work is performed by the marker or the image processing without using the above-mentioned self-positioning technique using satellites or self-positioning technique by dead-reckoning in a specific work area. In many cases, a mark is detected, and a copying run is performed along the detected work mark.

[0005]

By the way, in order to improve the work efficiency of the autonomously traveling work vehicle, it is desirable to autonomously travel as fast as possible within the work area.

However, in any of the above-mentioned techniques of autonomous traveling control using satellite, autonomous traveling control by dead reckoning navigation, and autonomous traveling control by copying traveling, there is a time lag in distance measurement, so autonomous operation is performed at high speed within the work area. When running, there is a risk of deviating from the work area, and it may be difficult to return to the original work area in some cases.

The present invention has been made in view of the above circumstances, and enables high-speed traveling within a work area by reliably preventing the autonomous vehicle from departing from the work area.
It is an object of the present invention to provide a work area deviation preventing device for an autonomous traveling work vehicle that can improve work efficiency.

[0008]

According to the present invention, there is provided work area deviation detection means for detecting an autonomously traveling work vehicle which is arranged on the outer circumference of a specific work area and crosses the outer circumference, and wirelessly transmits a detection signal. A control means for receiving a detection signal from the work area deviation detection means to control the steering system of the autonomous traveling work vehicle and preventing deviation from the work area.

[0009]

According to the present invention, when the autonomously traveling work vehicle crosses the outer circumference of the work area within a specific work area, a detection signal is transmitted from the work area deviation detecting means arranged on the outer circumference.
Then, the detection signal is received by the control means to control the steering system of the autonomously traveling work vehicle, thereby preventing deviation from the work area.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. The drawings show an embodiment of the present invention, FIG. 1 is a block diagram of a control device, and FIG. 2 is an explanation showing a lawnmower equipped with a D-GPS mobile station, a D-GPS fixed station, and a light-emitter / receiver. FIG. 3 is an explanatory view showing the configuration of a cut mark boundary detection mechanism, FIG.
Is an explanatory view showing the operation of the cut boundary detecting mechanism, FIG. 5 is an explanatory view showing an arrangement example of light projecting and receiving devices, FIG. 6 is an explanatory view showing the configuration of the steering control system, and FIG. 7 is a traveling route and a work area. Illustration,
8 and 9 are flowcharts of the main control routine, FIG.
0 and FIG. 11 are flowcharts of the autonomous traveling control routine, FIG. 12 is a flowchart of the cut boundary detection routine,
FIG. 13 is a flowchart of the D-GPS wireless communication routine.

In FIG. 2 (a), reference numeral 1 indicates an unmanned and self-propelled autonomous vehicle, and in this embodiment,
It is a lawn mowing vehicle for grass and lawn mowing work at golf courses and the like.
This lawnmower vehicle 1 is driven by an engine and can control the steering angles of the front and rear wheels independently, and is a satellite radio wave for receiving a radio wave from a satellite to measure its own position. Receiver, dead-reckoning sensor for measuring the current position based on the traveling history, sensor for detecting obstacles running, cut marks for copying along grass boundaries in the grass / lawn mowing work area A sensor that detects the boundary,
In order to prevent deviation from the work area, a wireless receiver or the like that receives signals from light-emitters arranged on the outer periphery of the grass / lawn mowing work area is mounted, and highly accurate autonomous traveling can be performed.

In the present embodiment, the satellite radio receiver is a GPS receiver for receiving radio waves from GPS satellites to measure its own position, and position observation is performed by a fixed station placed at a known point. This is a mobile station GPS receiver for so-called differential GPS (hereinafter abbreviated as D-GPS) that performs the above-mentioned operation and feeds back correction information (differential information) to the mobile station.

As is well known, the causes of positioning errors by GPS are errors of clocks of satellites and receivers, errors of orbits of satellites, delay of radio waves by the ionosphere, delay of radio waves by the atmosphere, multipath, etc. In addition, the largest error factor is selectable availability (S / A)
There is a deliberate deterioration in accuracy called by the operator. Of the errors due to these factors, the in-phase error can be removed by using the correction information corresponding to each satellite captured by the fixed station at a known point, and the positioning accuracy at the mobile station is about several meters. Can be dramatically improved.

For this reason, the lawnmower vehicle 1 has an antenna 2 for a mobile station GPS receiver and an antenna 3 for a wireless communication device for receiving differential information from a fixed station.
Are installed upright, and at a known point outside the vehicle, as shown in FIG. 2B, the antenna 3 of the fixed station GPS receiver is installed.
1 and a fixed station 30 equipped with an antenna 32 of a wireless communication device for transmitting differential information to a mobile station GPS receiver.

As the dead reckoning sensor, a geomagnetic sensor 4 and a wheel encoder 5 are used for the lawnmower work vehicle 1.
And a non-contact sensor 6a, 6b such as an ultrasonic sensor or an optical sensor as the obstacle detection sensor.
Is attached to the front and rear of the lawnmower 1 and
Contact type sensors 7a, 7b using a micro switch or the like
Are attached to the front and rear ends of the lawnmower work vehicle 1.

Further, the lawnmower work vehicle 1 serves as a work area deviation detecting means for detecting an autonomous traveling work vehicle which is arranged on the outer circumference of a specific work area and crosses the outer circumference, and wirelessly transmits a detection signal. The antenna 8 for receiving the signal from the detector 40 is installed upright.

In the present embodiment, the detector 40 is a detector using a photoelectric sensor, and a plurality of detectors 40 are arranged so that the outer circumference of the grass / lawn mowing work area is approximated by a straight line, as shown in FIG. 2 (c). And a projector 41 for projecting light, and this projector 4
It is a combination with a light receiver 42 that receives the light from 1. Further, the light receiver 42 wirelessly transmits a detection signal (ON-OFF signal) when the lawnmower working vehicle 1 crosses between the light projector 41 and the light receiver 42 and light is blocked. Transmitter and its antenna 4
3 and 3 are provided.

On the other hand, at the lower part of the vehicle body of the lawnmower work vehicle 1, a cutting blade mechanism 9 such as a mower for performing grass / lawn mowing work.
And a cut mark boundary detection mechanism 10 for detecting a cut mark boundary of grass / lawn mowing work.

The cut boundary detecting mechanism 10 is constituted by arranging two sets of mechanisms for detecting heights of grass and lawn in parallel on the left and right sides of the vehicle body. The front view of FIG. As shown in the side view of FIG. 2b), each mechanism has a grass, a lower end of each swinging member 12a, 12b rotatably supported by the vehicle body 1a of the lawn mower 1 via shafts 11a, 11b. Sled-shaped plates 13a and 13b that move up and down according to the length of the grass are rotatably suspended. The rocking members 12a, 12
b is fixed to the left and right shafts 11a and 11b, respectively, and the respective rotation angles are detected by the rotation angle sensors 14a and 14b attached to the left and right shafts 11a and 11b, respectively. .

The vehicle body 1 through the swing members 12a and 12b.
The sled-shaped plates 13a and 13b suspended on a are light enough not to crush grass / turf, and when the lawn mowing vehicle 1 moves, it moves up and down according to the height of the grass / turf. The swinging members 12a and 12b rotate, and the respective rotation angles are detected by the rotation angle sensors 14a and 14b.

Further, as shown in FIG. 1, the lawnmower vehicle 1 is equipped with a control device 50 including a microcomputer and the like, and sensors and actuators are connected to the control device 50. , Mobile station GP
The S receiver 15, the wireless communication device 16 for receiving the differential information from the fixed station 30, and the wireless communication device 17 for receiving the detection signal from the detector 40 are connected,
A self-positioning function by D-GPS, a self-positioning function by dead-reckoning, and an autonomous traveling control function for controlling autonomous traveling are realized, and a detection signal from the detector 40 is received to mow the lawn in the work area. The steering system of the vehicle 1 is controlled to realize a function as control means for preventing deviation from the work area.

Specifically, the cut boundary detection unit 51 to which the rotation angle sensors 14a and 14b of the cut boundary detection mechanism 10 are connected, the dead reckoning position detection unit to which the geomagnetic sensor 4 and the wheel encoder 5 are connected. 52, the mobile station GPS
DG to which the receiver 15 and the wireless communication device 16 are connected
The PS position detector 53, the obstacle detector 54 to which the contactless sensors 6a and 6b and the contact sensors 7a and 7b are connected, the photoelectric sensor information receiver 55 to which the wireless communication device 17 is connected, Each detector 51, 52, 53,
54 and 55 are connected to a travel control unit 56, a work data storage unit 57 that stores a work data map referred to by the travel control unit 56, and a vehicle that performs vehicle control according to an instruction from the travel control unit 56. A control unit 58 is provided in the control device 50, and further, the vehicle control unit 5
A drive control unit 59, a steering control unit 60, and a cutting blade control unit 61 are provided to drive the respective mechanical units of the lawnmower work vehicle 1 based on the output from 8.

The cut boundary detection unit 51 processes the rotation angle signals from the rotation angle sensors 14a and 14b of the cut boundary detection mechanism 10 in accordance with the grass / turf height, and cuts the grass / turf boundary. Detect the position. That is, in the grass / lawn mowing work area, as shown in FIGS. 4A and 4B, the rotation angle θ1 detected by one rotation angle sensor 14a and the rotation angle θ1 detected by the other rotation angle sensor 14b. When the difference from the turning angle θ2 is a certain value or more, the position is detected as a cut boundary between the cut and uncut portions, and the position data of the cut boundary is used as the travel control unit 5
Output to 6.

The dead reckoning position detecting unit 52 integrates the vehicle speed detected by the wheel encoder 5 to obtain the traveling distance, and accumulates the traveling distance in correspondence with the change in the traveling direction detected by the geomagnetic sensor 4. By doing so, the travel history from the reference point is calculated, the current position of the vehicle is measured, and the positioning data is output to the travel control unit 56. The sensors connected to the dead reckoning position detector 52 include the geomagnetic sensor 4 and the wheel encoder 5.
The combination is not limited to the above, and a gyro or the like may be combined.

The D-GPS position detector 53 includes a group of GPS satellites captured via the mobile station GPS receiver 15 (at least four in the case of three-dimensional positioning and at least three in the case of two-dimensional positioning). ) Navigation message from 70,
That is, satellite clock correction coefficient, orbit information, satellite calendar,
The position of the vehicle is measured with high accuracy based on positioning information such as satellite arrangement and the differential information received from the fixed station 30 via the wireless communication device 16, and the positioning data is output to the travel control unit 56. .

The fixed station 30 for the D-GPS position detector 53 is a D- to which a fixed station GPS receiver 33 is connected.
GPS fixed station section 34, D-GPS for transmitting the differential information from this D-GPS fixed station section 34
The information transmitter 35 includes a wireless communication device 36 connected to the D-GPS information transmitter 35.

In the D-GPS fixed station section 34, the satellite group 70 received via the fixed station GPS receiver 33.
And processing the positioning information from to create differential correction data. This differential correction data is
The D-GPS information transmission unit 35 converts the packet data into wireless communication data and transmits the packet data via the wireless communication device 36.

In the present embodiment, the D-GPS fixed station 30 is installed as a specific device for the mobile station of the lawnmower work vehicle 1, but it is a radio that transmits differential information. Existing D-GP with stations
It is also possible to use an S fixed station or an existing D-GPS fixed station that transmits differential information via a communication satellite.

The obstacle detecting section 54 includes the non-contact type sensors 6a and 6b and the contact type sensors 7a and 7a.
An obstacle that cannot be predicted is detected by 7b, and a detection signal is output to the traveling control unit 56.

Further, the photoelectric sensor information receiving section 55 is
The detection signal from the light receiver 42 is received, the end point of the work route in the grass / lawn mowing work area is detected, and output to the traveling control unit 56. The light receiver 42 includes a photoelectric sensor light receiver 44, a photoelectric sensor transmitter 45, and a wireless transmitter 46.
The photoelectric sensor light receiving unit 44 receives the light from the projector 41 and converts the light into an electric signal, the photoelectric sensor transmitting unit 45 converts the light signal into a wireless signal, and the photoelectric sensor information via the wireless transmitter 46. It is adapted to be transmitted to the receiving unit 55.

For example, the lawn mowing vehicle 1 travels in parallel work paths as shown in FIG.
When performing lawn mowing work, two sets of the light projector 41 and the light receiver 42 are arranged so as to sandwich the end of each row of the work path, and light is projected from the light projector 41. When the lawnmower 1 reaches the end point of the work route and crosses between the projector 41 and the photoreceiver 42, the light is blocked, and an ON-OFF signal is output to the photoelectric sensor information receiver 55. Sent.

In the photoelectric sensor information receiving section 55, an ON-OFF signal from the photodetector 42 is used to indicate the work path 1
The end point position information of the row is obtained and output to the traveling control unit 56,
The traveling direction of the lawn mowing vehicle 1 is changed to prevent the lawn mowing vehicle 1 from departing from the work area. As a result, it is possible to drive at high speed within the work area, and work efficiency can be significantly improved.

In the traveling control unit 56, the cut boundary detection unit 51, the dead reckoning position detection unit 52, the D-GP.
Each positioning data from the S position detection unit 53 is selected as appropriate, the error amount between the current position and the target position is calculated by referring to the work data of the work data storage unit 57, and the travel route and the vehicle control instruction are determined. .

In this case, when moving to the work area,
When the positioning accuracy of the D-GPS position detector 53 is compared with a set level and the set level is satisfied, the D-GP
When the positioning data from the S position detecting unit 53 is used and the set level is not satisfied, the autonomous traveling control is performed using the positioning data from the dead reckoning position detecting unit 52. Then, in the grass / lawn mowing work in the work area, the data from the cut boundary detecting unit 51 and the photoelectric sensor information receiving unit 5 are used.
The data from 5 is used to control the copying travel.

The work data storage unit 57 is composed of a ROM area for storing fixed data and a RAM area for storing work data under control execution. In the ROM area, work for performing grass / lawn mowing work is performed. The terrain data of the area, the terrain data of the entire area including a plurality of work areas, and the like are stored in advance, and in the RAM area, as described later,
In order to correct the dead reckoning positioning data, the D-GPS positioning data is accumulated within a set time.

The vehicle control unit 58 converts the instruction from the traveling control unit 56 into a specific control instruction amount and outputs it to the drive control unit 59, the steering control unit 60, and the cutting blade control unit 61. As a result, in the drive controller 59, the hydraulic pump 21
To generate hydraulic pressure for driving each functional unit,
In the steering control unit 60, steering control (steering amount feedback control) is performed via the front wheel steering hydraulic control valve 22a and the rear wheel steering hydraulic control valve 22b based on the inputs from the front wheel steering angle sensor 25a and the rear wheel steering angle sensor 25b. The cutting blade control unit 61 performs servo control of the cutting blade mechanism 9 via the cutting blade control hydraulic control valve 26.

As shown in FIG. 6, the steering system of the lawnmower working vehicle 1 includes a hydraulic pump 2 driven by an engine 20.
1, a front wheel steering hydraulic control valve 22a and a rear wheel steering hydraulic control valve 22b controlled by the steering control section 60 are connected, and the hydraulic control valves 22a and 22b are connected to
Front wheel hydraulic cylinder 23a, rear wheel hydraulic cylinder 23b
Are respectively connected to each of the hydraulic cylinders 23a, 2
3b, front wheel steering mechanism 24a, rear wheel steering mechanism 24b
Are driven independently.

When the steering angles of the front and rear wheels detected by the steering angle sensors 25a and 25b attached to the steering mechanisms 24a and 24b are input to the steering control section 60, the detected steering angles are The steering control unit 60 controls the steering mechanisms 24a and 24b via the hydraulic control valves 22a and 22b so as to eliminate the deviation from the target steering angle.

The case where unmanned grass / lawn mowing work is performed on a plurality of divided work areas as shown in FIG. 7 will be described below. In this case, assuming that the lawn mowing vehicle 1 is waiting at an arbitrary preparation position 80 before starting work, it moves to the first work area 82, the grass / lawn mowing work in this work area 82, and the next from the work area 82. The movement to the work area 85, the grass / lawn mowing work in the work area 85, and the movement to the return position 88 are autonomously performed according to the programs shown in FIGS.

First, in the main control routine shown in FIGS. 8 and 9, in step S101, the preparation position 80, which is the current self-position, is measured using the D-GPS. This position measurement is
It is performed by converting the D-GPS positioning data such as longitude and latitude (altitude data is also added if necessary) into geodetic system data stored in the work data storage unit 57. Data conversion to this geodetic system is performed by D-GPS.
It may be performed by the position detection unit 53 or the traveling control unit 56.

Next, in step S102, the topographical data of the first work area 82 is read out by referring to the work data storage unit 57, and a route 81 from the measured preparation position 80 to the work start point is generated, and in step S103. Go to. Step
In S103, the vehicle is moved to the work start position by executing the autonomous traveling control routine of FIGS. 10 and 11 which will be described later, and in step S104, the cutting blade control hydraulic control valve 26 is opened to cause the cutting blade mechanism 9 to operate. Supply the hydraulic pressure and operate the cutting blade to start grass and lawn mowing work.

Then, in step S105, it is checked whether or not it is the first work, and when it is the first work, the process proceeds from step S105 to step S106, and is performed by the D-GPS or dead reckoning during autonomous driving in step S103. After detecting its own position, in step S107, the work data storage unit 5
Work 1 in work area 82 with reference to work data 7
The amount of error from the current position for the route of the first stroke (one column) is calculated.

Next, the process proceeds to step S108, and the step
The steering amount for each target steering angle of the front and rear wheels is determined according to the error amount obtained in S107, and in step S109, the front wheel steering mechanism is operated via the front wheel steering hydraulic control valve 22a and the rear wheel steering hydraulic control valve 22b. 24a and the rear wheel steering mechanism 24b are respectively driven, and the front wheel steering angle sensor 25a and the rear wheel steering angle sensor 25b detect the front wheel steering angle and the rear wheel steering angle to perform control so as to obtain the target steering angle.

After that, in step S110, when the sensor information is received from the photoelectric sensor information transmitting section 45, the lawn mower 1
Is crossed over the outer circumference of the work area, the light from the projector 41 is blocked, and the signal from the receiver 42 is turned from ON to OFF to reach the end point of one stroke (one column).
If you checked in step 11 and you have not reached the end point,
The process returns to S106 to continue the grass and lawn mowing work, and when the terminal point is reached, the process proceeds from step S111 to step S119.

In step S119, the self position is detected by D-GPS or dead reckoning, and the process proceeds to step S120,
The detected self-position is the end of one section, and it is determined whether or not the work in one section is completed. In this case, work 1
Since it is the first time, the process from step S120 to step S105
Then, it is checked again whether or not it is the first work, and when it is the second or later work, the process branches from step S105 to step S112 to follow the work route 83 along the cut boundary.

That is, in step S112, the vehicle body is laterally shifted by the width of the cutting blade and moved to the next work position. In step S113, the cut boundary detection routine shown in FIG. The rotation angle sensor 14a of the mechanism 10,
Based on the signal from 14b, the cut boundary of the previous work is detected. Then, in step S114, the cut boundary and the vehicle position are compared to obtain an error amount for realizing the set lawn mowing overlap amount.

Next, the process proceeds to step S115, and when the steering amounts of the front and rear wheels are determined according to this error amount, step S116
The front wheel steering mechanism 24a and the rear wheel steering mechanism 2 are connected via the front wheel steering hydraulic control valve 22a and the rear wheel steering hydraulic control valve 22b.
4b are respectively driven and controlled to obtain the target rudder angle.

After that, in step S117, the sensor information is received again from the photoelectric sensor information transmitting unit 45, and in step S118.
Similarly, it is checked whether or not the one stroke end point is reached, and if the one stroke end point is not reached, the above-mentioned step S113 is performed.
Returning to step S3, the contour traveling is continued along the cut boundary, and when the end point of one stroke is reached, the self position is detected in step S119, and the work of one section (work area 82) is completed in step S120. Judge whether or not.

Then, steps S105 to S120 are repeated until the work in one section (work area 82) is completed, and when the work in one section is completed, the process proceeds from step S120 to step S121, and the work in all the sections is completed. Judge whether or not. Here, since the work in the next work area 85 has not been completed yet, the process returns to the step S102 described above, and if the route 84 from the work area 82 to the work area 85 is generated by the same procedure, FIG. In accordance with the autonomous traveling control routine of 11, the robot moves to the next work area 85 and performs grass and lawn mowing work.

Eventually, when all the work is completed, step S1
When the process proceeds from step 21 to step S122 and the route 87 to the return position 88 is generated by referring to the work data storage unit 57, the process moves to the return position 88 according to the autonomous traveling control routine of FIGS. Stop and stop the vehicle.

Next, the autonomous traveling on the routes 81, 84, 87 by the autonomous traveling control routine shown in FIGS. 10 and 11 will be described. In the main control routine described above, the routes 81, 84 and 87 are generated from the positioning data of the self position and the work data of the work data storage unit 57. However, the routes 81, 84 and 87 themselves are previously generated. It may be stored in the work data storage unit 57.

In the self-position measurement by D-GPS, much better accuracy can be obtained as compared with the case of a single GPS, but it is necessary for autonomous traveling control depending on the satellite capture state, the radio wave reception state, and the like. The accuracy required for timing may not be obtained. Therefore, when the current D-GPS accuracy information is obtained in step S201, in step S202
This accuracy information is compared with a prescribed position accuracy evaluation set value stored in advance in the work data storage unit 57, and step S2
At 03, it is determined whether or not the positioning accuracy of D-GPS satisfies the set level.

When the positioning accuracy of D-GPS satisfies the set level, the process proceeds to step S204, and the moving speed of the lawnmower work vehicle 1 becomes the normal speed stored in the work data storage unit 57. Control, and in step S205, D
When the error amount of the vehicle position is obtained from the GPS position information and the route information, the steering amounts of the front and rear wheels are determined according to the error amount in step S206.

Next, in step S207, the front wheel steering mechanism 24a and the rear wheel steering mechanism 24b are respectively driven via the front wheel steering hydraulic control valve 22a and the rear wheel steering hydraulic control valve 22b to obtain the target steering angle. Control, step S208
Then, the current position measured by D-GPS is compared with the target position, and it is determined in step S209 whether or not the target position has been reached. As a result, when the target position is not reached,
Returning to step S204, the vehicle continues traveling while positioning the current position by the D-GPS, and when the vehicle reaches the target position, the vehicle is stopped and the routine exits in step S225.

On the other hand, if the positioning accuracy of the D-GPS does not satisfy the set level in step S203, the process branches from step S203 to step S210 and onward, and the dead reckoning autonomous driving is performed. That is, in step S210, the moving speed of the vehicle is set to the low speed stored in the work data storage unit 57 to minimize the dead-reckoning cumulative error caused by the slip of the wheels. Then, the error amount of the vehicle position is obtained from the position information and the route information based on dead reckoning.

Next, in step S212, the steering amount of the front and rear wheels is determined according to the error amount. In step 213, the front wheel steering mechanism 24a is operated via the front wheel steering hydraulic control valve 22a and the rear wheel steering hydraulic control valve 22b. The rear wheel steering mechanism 24b is driven to control the target steering angle. Then, in step S214, the current position by dead-reckoning and the target position are compared, and in step S215, it is determined whether or not the target position has been reached.

When the target position has not been reached, the process returns from step S215 to step S210 to continue autonomous traveling while positioning the current position by dead reckoning. When the target position is reached, the process proceeds from step S215 to step S216. When the current position is stopped, the current position is measured by the D-GPS and the positioning data is stored in the work data storage unit 57 in step S217.
In the RAM area.

After that, the process proceeds to step S218, the preset data storage set time is compared with the data storage time set in step S217, and it is checked in step S219 whether the set time has elapsed. Then, when the set time has not elapsed, the process returns to step S217 to continue accumulating the positioning data by D-GPS, and when the set time elapses, the accumulation of the positioning data by D-GPS ends and the process proceeds to step S220. .

In step S220, the accumulated positioning data by D-GPS is averaged, and the current position is obtained from this average value. Then, the process proceeds to step S221, the current position and the target position are compared, and in step S222, the true value is determined. It is determined whether the target position has been reached. As a result, if it is determined that the true target position has been reached, the vehicle is stopped and the routine exits in step S225, and if it is determined that the true target position has not been reached, the step In S223, when the dead reckoning positioning data is corrected by the average value of the positioning data by D-GPS, the process proceeds to step S224 to generate a route to the true target position, and the process returns to step S210 to restart the traveling,
The above processing is repeated until the true target position is reached.

That is, even when the positioning accuracy of the D-GPS is deteriorated, the positioning accuracy can be improved by staying at a certain point and continuing the measurement for a predetermined time, which is required by the D-GPS during autonomous traveling. When the position accuracy cannot be obtained, the dead reckoning navigation is performed to reach the target position and then stopped, and the D-GPS positioning data is accumulated for a set time in the stopped state and the average value is obtained to obtain the accurate current position. be able to. When the target position by dead reckoning is deviated, the dead reckoning positioning data is corrected by the average value of the set times of the D-GPS positioning data, so that reliable autonomous traveling can always be performed. is there.

Next, a description will be given of the process of detecting the boundary of the cut mark in the copying run in the grass / lawn mowing work area. In this cut boundary detection process, in step S301 of FIG. 12, data such as grass and lawn mowing height in the target work area is set, and in step S302, each rotation angle sensor 14a of the cut boundary detecting mechanism 10 is set. , 14b, the angles of the rocking members 12a, 12b for suspending the left and right sled-shaped plates 13a, 13b which move up and down according to the height of grass / lawn cutting are detected.

Next, the routine proceeds to step S303, where it is checked whether or not a fixed time has elapsed. If the fixed time has not elapsed, then the operation proceeds to step S302 described above to accumulate angle data. After that, when a predetermined time has elapsed and a predetermined number of angle data are accumulated, the process proceeds from step S303 to step S304 to average the accumulated left and right angle data, and the data set in step S301 is referred to. Convert to left and right grass / turf length.

Then, the steps S304 to S3 are performed.
Go to 05, check whether there is a step greater than a predetermined value on the left and right grass / turf height converted in step S304.If there is no step more than the predetermined value, it is determined in step S306 that there is no boundary line. Returning to step S302, if there is a step difference equal to or larger than the predetermined value, the process proceeds to step S307 to capture the current position as a boundary line between the cut and uncut portions, and exits the routine.

Data communication between the fixed station 30 and the mobile station in D-GPS is performed by packet data by the D-GPS wireless communication routine shown in FIG. In this data communication, the mobile station GPS receiver 15 is initialized in step S401, and the fixed station GPS receiver 33 is initialized by data transmission through the wireless communication devices 16 and 36 in step S402. Then, the differential information from the fixed station 30 is obtained by wireless data communication.

Then, in step S404, the D-GP
The S position detection unit 53 applies the differential information from the fixed station 30 to the positioning data obtained from the mobile station GPS receiver 15 and performs the differential calculation to measure the own vehicle position. Then, the positioning information is transmitted to the travel control unit 5
When sent to step 6, the process returns to step S403 and the next data processing is repeated. In this case, the differential calculation with the fixed station 30 may be performed by a function unique to the mobile station receiver 15.

In this embodiment, the autonomous traveling in the work area is used as a model traveling. However, the present invention is not limited to this, and autonomous traveling and estimation in the work area by self-positioning using satellites are possible. The present invention may be applied to autonomous traveling in a work area by navigation, autonomous traveling in a work area in which self-positioning using satellites and self-positioning by dead reckoning are combined, and the like.

[0067]

As described above, according to the present invention, when the autonomous traveling work vehicle crosses the outer periphery of the specific work area, a detection signal is transmitted from the work area deviation detecting means arranged on the outer periphery, Since this detection signal is received by the control means to control the steering system of the autonomously traveling work vehicle, it is possible to reliably prevent the autonomously traveling work vehicle from departing from the work area, and to autonomously travel within the work area. Excellent effects such as high-speed traveling of the work vehicle and improved work efficiency can be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram of a control device.

FIG. 2 is a lawn mower equipped with a D-GPS mobile station and D-
Explanatory drawing showing a fixed station for GPS and an emitter / receiver

FIG. 3 is an explanatory diagram showing a configuration of a cut boundary detecting mechanism.

FIG. 4 is an explanatory diagram showing an operation of a cut boundary detecting mechanism.

FIG. 5 is an explanatory diagram showing an example of the arrangement of light emitters / receivers.

FIG. 6 is an explanatory diagram showing a configuration of a steering control system.

FIG. 7 is an explanatory diagram showing a travel route and a work area.

FIG. 8 is a flowchart of a main control routine.

FIG. 9 is a flowchart of a main control routine (continued)

FIG. 10 is a flowchart of an autonomous traveling control routine.

FIG. 11 is a flowchart of an autonomous traveling control routine (continued)

FIG. 12 is a flowchart of a cut boundary detection routine.

FIG. 13 is a flowchart of a D-GPS wireless communication routine.

[Explanation of symbols]

 1 Lawnmower work vehicle (autonomous traveling work vehicle) 40 Detector (work area deviation detection means) 50 Control device (control means)

Claims (1)

[Claims] 1. A work area deviation detection means (40) for detecting an autonomously traveling work vehicle (1) arranged on the outer circumference of a specific work area and crossing the outer circumference, and wirelessly transmitting a detection signal, And a control means (50) for receiving a detection signal from the work area deviation detection means (40) to control the steering system of the autonomous traveling work vehicle (1) and preventing deviation from the work area. A work area deviation prevention device for an autonomously-operated work vehicle.