JPH07184413A - Apparatus for detecting boundary of reaped track and autonomously traveling working vehicle - Google Patents

Abstract

PURPOSE:To surely detect the boundary between a non-reaped field and a reaped field independent of the working environment such as dust and mud even in the case of short grass or lawn length to cause small difference of the grass length between the non-reaped field and the reaped field. CONSTITUTION:Plural shafts 11a, 11b rotatably supported under a chassis are arranged in parallel in the lateral direction of the chassis. Each shaft 11a, 11b is provided with a swinging member 12a, 12b having a length nearly equal to or longer than the ground height of each shaft and fixed in a state suspended from the shaft. A sleigh-formed plate 13a, 13b is rotatably attached to the lower end of each swinging member 12a, 12b and the plate is provided with a rotary angle sensor 14a, 14b to detect the rotation angle of each shaft 11a, 11b. The length of the swinging member 12a, 12b is selected to be nearly equal to or longer than the ground height of each shaft 11a, 11b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cut mark boundary detecting device for detecting a cut mark boundary between an uncut land and an already cut land in a grass / lawn mowing work area, and a cut mark detected by the cut mark boundary detecting device. The present invention relates to an autonomous traveling vehicle that autonomously travels along a boundary to perform grass and lawn mowing work.

[0002]

2. Description of the Related Art Conventionally, for an autonomous vehicle that is autonomously autonomously traveling, there is a technique in which an electric wire is buried underground and a magnetic sensor detects a magnetic field generated by the electric wire as self-position detection for autonomous traveling. Although proposed (for example, Japanese Patent Laid-Open No. 1-
No. 312610), a golf course, a river embankment, a field such as a park, etc., where an autonomous traveling area is large, such as an autonomous traveling vehicle that performs unmanned work such as mowing and lawn mowing.
It is difficult to embed the electric wire in the whole area, and the installation cost becomes large.

In order to cope with this, a boundary between an uncut land as an unprocessed work site and an already cut land as a processed work site, that is, a cut boundary, is detected in the grass / lawn mowing work area, and this cut boundary is detected. An autonomous mobile work vehicle has been developed that autonomously travels along the road to perform grass and lawn mowing work.

Regarding the detection of the boundary of the cut mark, Japanese Patent Laid-Open No. Sho 61-61
No. 139304, a monitor camera captures an image of a boundary portion, and the captured image is binarized by an average brightness difference.
At the time of value conversion, the positive and negative signs of the differential value are detected and compared with the traveling direction of the vehicle to identify whether it is worked / unworked / boundary or unworked / worked / boundary,
A technique is disclosed in which only the necessary boundary is found in the current work process and the vehicle autonomously travels along this boundary.

Further, Japanese Patent Publication No. 4-39286 discloses that
A scanning sensor composed of two photointerrupter type optical sensors in which a pair of a light emitting element and a light receiving element are arranged at positions facing each other through a slit is suspended on the vehicle body so as to be aligned in the left-right direction with respect to the vehicle body. Each of the optical sensors is attached to the front end of each frame before and after being fixed to the lawnmower and detects the presence of lawn passing between the light emitting element and the light receiving element. , Which is above, and the combination of the detection results, that is,
The state where the optical sensor on the boundary side and outside the vehicle body detects the already cut land and the optical sensor inside the vehicle body detects the uncut area is defined as the state along the cut line boundary. A technique is disclosed in which a positional relationship with a vehicle body is discriminated and the vehicle autonomously travels along a cut mark boundary.

[0006]

However, the copying traveling by image processing as in the first prior art requires a video camera and an image processing device, which leads to an increase in cost, and the image pickup surface of a camera lens or the like. If dust, mud, etc. adheres,
A clear image cannot be obtained, it becomes difficult to detect the boundary, and maintenance and inspection work such as cleaning of the imaging surface such as the camera lens needs to be done frequently, and it is also necessary to take waterproof measures on the video camera. There are inconveniences such as.

Further, as shown in the second prior art example, a scanning sensor comprising two photo interrupter type optical sensors in which a light emitting element and a light receiving element are arranged in a pair so as to face each other through a slit is used. In this case, if dust, mud, or the like adheres to the light-emitting surface of the light-emitting element and the light-receiving surface of the light-receiving element, the light from the light-emitting element is always blocked, and even if it is already cut, it is erroneously detected as uncut. There is a disadvantage that autonomous traveling along the cut boundary becomes impossible.Furthermore, the copying sensor has a structure in which a slit in which a light emitting element and a light receiving element are arranged to face each other is rigidly fixed to the frame of the lawnmower, so In order to prevent damage to the scanning sensor due to collision with the ground, it is necessary to secure a certain space (ground clearance) between the scanning sensor and the ground. The grass length is low If the difference ShibaTake with non cutting locations and Sundekari land is small, there is a disadvantage that can not be detected Kariato boundaries.

In view of the above circumstances, the present invention is not affected by the environment in which it is used, such as dust and mud, and the grass on the uncut area is low and the grass height is low. It is a first object of the present invention to provide a cut mark boundary detection device that reliably detects a cut mark between uncut land and already cut land even when the difference in grass height is small. Further, it is a second object of the present invention to provide an autonomous traveling work vehicle in which the above-described cut boundary detection device is applied to an autonomous traveling work vehicle to surely perform autonomous traveling along the cut boundary regardless of the use environment. To aim.

[0009]

In order to achieve the first object, a cut boundary detecting device according to the present invention has a plurality of shafts rotatably supported on the lower part of a vehicle body arranged side by side in the lateral direction of the vehicle body.
A swing member having a length substantially the same as or longer than the ground height of each shaft is fixed to the plurality of shafts, respectively, and a sled plate is rotatably suspended at the lower end of each swing member. ,
A rotation angle sensor for detecting a rotation angle of each of the axes is provided.

In order to achieve the above-mentioned second object, the autonomous traveling work vehicle according to the present invention has a plurality of rotatably supported shafts arranged side by side in the left-right direction of the vehicle body under the vehicle body of the autonomous traveling work vehicle. , A swing member having substantially the same length as the ground height of each shaft or longer than that is suspended and fixed to each of the plurality of shafts, and a sled plate is rotatably suspended at the lower end of each swing member. However, it is equipped with a rotation angle sensor that detects the rotation angle of each axis, inputs the signal from the rotation angle sensor, and when the difference from the rotation angle of each axis is a certain value or more, move that position to the grass / lawn mowing work. The present invention is characterized by including a control unit that detects a cut mark boundary between an already-cut land and an uncut land in a region and controls the steering mechanism based on the position data of the cut mark boundary.

[0011]

In the above-described cut boundary detecting device, sled-shaped plates positioned in parallel in the left-right direction of the vehicle body are moved up and down in accordance with the length of grass and lawn, and accordingly, the shafts are rotatably supported at the lower portion of the vehicle body. Rotates via the swing member, and the rotation angle of each shaft is detected by the rotation angle sensor.

Further, in the above-mentioned autonomous traveling work vehicle, sled-like plates which are arranged in parallel in the lateral direction of the vehicle body depending on the length of grass and turf are respectively moved up and down as the vehicle advances and are rotatably supported at the lower portion of the vehicle body. Each shaft is rotated via the swing member, and a signal corresponding to the rotation angle of each shaft is output from the rotation angle sensor to the control device, and the control device causes the difference in the rotation angle of each shaft to be a certain value or more. At that time, the position is taken as the position data of the cut mark boundary between the existing and uncut areas in the grass / lawn mowing work area, and the steering mechanism is controlled based on this position data to follow the cut mark boundary. Autonomous driving is performed.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. The drawing shows an embodiment of the present invention, and FIG. 1 shows a D-GP.
FIG. 3 is an explanatory view showing a lawnmower equipped with a mobile station for S and a fixed station for D-GPS, FIG. 2 is a plan view showing a mounting position relationship between a cutting blade mechanism and a cut boundary detection device in the lawn mowing vehicle, and FIG. Is an explanatory view showing the configuration of the cut boundary detection device, FIG. 4 is an explanatory diagram showing the operation of the cut boundary detection device, FIG. 5 is a block diagram of the control device, FIG. 6 is an explanatory view showing the configuration of the steering control system, 7 is an explanatory view showing a traveling route and a work area, FIGS. 8 to 10 are flowcharts of a main control routine, and FIGS. 11 and 12 are flowcharts of an autonomous traveling control routine. FIG. 13 is a flowchart of the cut boundary detection routine, and FIG. 14 is a D-GPS.
Wireless communication routine flow chart, FIG. 15 and FIG.
FIG. 6 is an explanatory diagram showing a vehicle shift state at the end of one stroke due to grass / lawn mowing work.

In FIG. 1 (a), reference numeral 1 denotes an autonomous traveling work vehicle that is self-propelled and is unmanned. In this embodiment, it is a lawn mowing work vehicle for performing grass and lawn mowing work on a golf course or the like. This lawnmower vehicle 1 is driven by an engine, and the steering angles of the front and rear wheels can be independently controlled.
Satellite radio receiver for receiving radio waves from satellites and measuring own position, dead reckoning sensor for measuring current position based on traveling history, sensor for detecting obstacles, grass and lawn mowing A sensor or the like for detecting a cut boundary for performing a contour running along the cut boundary in the work area is mounted, and highly accurate autonomous running 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 arranged at a known point. So as to feed back the correction information (differential information) to the mobile station, so-called differential GPS (hereinafter abbreviated as D-GPS).
Is a mobile station GPS receiver for.

As is well known, the causes of GPS positioning errors include satellite and receiver clock errors, satellite orbit errors, ionospheric radio wave delay, atmospheric radio wave delay, and multipath. 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.

Therefore, 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 location outside the vehicle,
As shown in, the antenna 31 of the fixed station GPS receiver,
Fixed station 3 with antenna 32 of a wireless communication device for transmitting differential information to a mobile station GPS receiver
0 is placed.

As the dead reckoning sensor, a geomagnetic sensor 4 and a wheel encoder 5 are used for the lawnmower 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, in the lower part of the body of the lawnmower working vehicle 1,
A cutting blade mechanism 9 provided with a plurality of cutting blades 9a such as mowers for performing grass / lawn mowing work, and cut mark boundary detection devices 10a, 10b for detecting the cut mark boundaries of grass / lawn mowing work are provided. ing.

As shown in FIG. 2, the cut boundary detecting device 1
0a and 10b are disposed on the frame 1b fixed to the lower part of the vehicle body 1a on the left side in the forward direction F of the lawn mowing work vehicle 1, and are disposed respectively before and after the cutting blade mechanism 9 so that the grass / turf height is increased. Two sets of mechanisms for detecting the are arranged in parallel in the lateral direction of the vehicle body. As shown in the front view of FIG. 3 (a) and the side view of FIG. 3 (b), each of the mechanisms includes a shaft 1 a, a shaft 1 a, and a frame 1 b extending from a lower portion of the vehicle body 1 a of the lawnmower working vehicle 1. 1
Rocking members 12a rotatably supported via 1b,
At the lower end of 12b, sled-shaped plates 13a and 13b that move up and down according to the grass / turf height are rotatably suspended. The sled-shaped plates 13a and 13b are
Regardless of whether the lawn mowing vehicle 1 is moving forward or backward, the grass and lawn are smoothed and the board 1
In order to guide them to the lower portions of 3a and 13b and prevent them from being caught, their front and rear directions are each formed in a sled shape.
The swing members 12a and 12b are connected to the left and right shafts 11 respectively.
It is fixed to a and 11b respectively, and the left and right shafts 11
The respective rotation angles are detected by the rotation angle sensors 14a and 14b formed of rotary encoders and the like attached to a 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 the lawn mower 1
When it moves, it moves up and down according to the height of the grass / turf, the swinging members 12a, 12b rotate, and the respective rotation angles are detected by the rotation angle sensors 14a, 14b.

Therefore, as shown in FIG. 4, one sled plate 13a in the cut boundary detecting device 10a (10b).
Is located on the cut land in the grass / lawn mowing work area, and the other sled plate 13b is located on the uncut land, through the swinging members 12a and 12b pivotally supporting the sled plates 13a and 13b. When the difference between the rotation angles θ1 and θ2 of the shafts 11a and 11b becomes large, and the difference between the rotation angles θ1 and θ2 is equal to or more than a preset constant value, both sled-shaped plates of the vehicle body 1a of the lawn mower 1 are provided. A cut mark boundary between the already-cut land and the uncut land is located between 13a and 13b, whereby the cut mark boundary can be detected.

The rocking member can be detected even when the grass / turf length in the uncut area is low and the difference in grass / turf length between the uncut area and the already-cut area is small. 12a, 12b
The length from the upper end to the lower end of the shaft is set to be substantially the same as or higher than the ground clearance of the shafts 11a and 11b.

Further, in the present embodiment, in the grass and lawn mowing work by the lawn mowing vehicle along the cut line boundary, the already-cut land C is always positioned on the left outer side of the vehicle body 1a, and uncut residue is prevented. In order to realize a predetermined lawn mowing overlap amount O, the positions between the sled-shaped plates 12a and 12b are set to the positions shown in FIG.
As shown in FIG. 5, the cutting blade mechanism 9 is set to be inside the tangent to the left cutting blade 9a in the front-back direction of the vehicle body 1a. As a result, due to the difference in the rotation angles, the sled-shaped plates 13a,
It is detected that the cut boundary line L between the already-cut land C and the uncut land B is located between 13b, and the lawn mowing vehicle 1 along the cut-line boundary line L between the already-cut land C and the uncut land B is detected. During the grass / lawn mowing work by the contour traveling of, it becomes possible to position the cut line boundary L inside the cutting blade 9a, and the uncut grass / lawn is prevented.

Further, as shown in FIG. 5, the lawnmower working vehicle 1 is equipped with a control device 50 composed of a microcomputer and the like.
Along with connecting actuators, mobile station GPS
The receiver 15 and the wireless communication device 16 for receiving the differential information from the fixed station 30 are connected to the D-GP.
A self-positioning function by S, a self-positioning function by dead-reckoning, and an autonomous traveling control function for controlling autonomous traveling are realized.

Specifically, the dead reckoning position detection to which the cut boundary detection unit 51 to which the rotation angle sensors 14a and 14b of the cut boundary detection device 10 are connected, the geomagnetic sensor 4 and the wheel encoder 5 is connected. The unit 52, the D-GPS position detection unit 53 to which the mobile station GPS receiver 15 and the wireless communication device 16 are connected, and the obstacle detection unit to which the non-contact type sensors 6a and 6b and the contact type sensors 7a and 7b are connected. 54, a travel control unit 55 to which these detection units 51, 52, 53, 54 are connected, and a work data storage unit 5 in which a work data map referred to by the travel control unit 55 is stored.
6. The control device 50 is provided with a vehicle control unit 57 that controls a vehicle in accordance with an instruction from the traveling control unit 55. Further, based on the output from the vehicle control unit 57, each mechanical unit of the lawnmower working vehicle 1 is controlled. For driving, a drive control unit 58, a steering control unit 59, and a cutting blade control unit 60 are provided.

The cut boundary detecting section 51 processes the rotation angle signals from the rotation angle sensors 14a and 14b of the cut boundary detecting device 10 according to the grass / turf heights to cut the grass / turf length. Detect the boundary position. That is, as described above (see FIGS. 4A and 4B), the rotation angle θ1 detected by one rotation angle sensor 14a and the rotation detected by the other rotation angle sensor 14b in the grass / lawn mowing work area. When the difference from the angle θ2 is a certain value or more, the position is detected as a cut boundary between the cut land B and the uncut land C, and the position data of the cut boundary is output to the traveling control unit 57. .

The dead reckoning position detector 52 integrates the vehicle speed detected by the wheel encoder 5 to obtain a traveling distance, and accumulates the traveling distance in correspondence with a change in 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 55. still,
The sensor connected to the dead reckoning position detection unit 52 is not limited to the combination of the geomagnetic sensor 4 and the wheel encoder 5, but a gyro or the like may be combined.

The D-GPS position detecting section 53 includes a group of GPS satellites captured through 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 from the 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 sent to the travel controller 55. Output.

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.

The D-GPS fixed station section 34 processes the positioning information from the satellite group 70 received via the fixed station GPS receiver 33 to create differential correction data. The differential correction data is converted into wireless communication packet data in the D-GPS information transmitting unit 35 and transmitted 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. However, a radio transmitting differential information is used. 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.

Further, the obstacle detecting section 54 detects an unpredictable obstacle by the non-contact type sensors 6a, 6b and the contact type sensors 7a, 7b, and outputs a detection signal to the traveling control section 55.

The traveling control unit 55 obtains the vehicle speed information based on the output of the wheel encoder 4, and each positioning from the cut boundary detection unit 51, dead reckoning position detection unit 52, and D-GPS position detection unit 53. Data is appropriately selected, the error amount between the current position of the vehicle and the target position is calculated by referring to the work data in the work data storage unit 56, and the travel route and the vehicle control instruction are determined. .

In this case, when moving to the work area,
When the positioning accuracy in the D-GPS position detecting unit 53 is compared with a set level and the set level is satisfied, the positioning data from the D-GPS position detecting unit 53 is used, and when the set level is not satisfied, The autonomous traveling control is performed using the positioning data from the dead reckoning position detecting unit 52. In the grass / lawn mowing work in the work area, the cut boundary detection unit 5
The data from 1 is used to control copying travel. When an obstacle is detected by the obstacle detection unit 54, an instruction to avoid the obstacle or stop the vehicle is issued.

The work data storage unit 56 comprises a ROM area in which fixed data is stored and a RAM area in which work data under control is stored.
Topographic data of the work area for grass and lawn mowing work in the M area
Data and terrain data of the entire area including a plurality of work areas are stored in advance. In the RAM area, as described later, in order to correct positioning data by dead reckoning, D- Positioning data of GPS is stored.

The vehicle control unit 57 converts the instruction from the traveling control unit 55 into a specific control instruction amount and outputs it to the drive control unit 58, the steering control unit 59, and the cutting blade control unit 60. As a result, the drive control unit 58 controls the vehicle traveling control actuator 17 such as the shift actuator, the forward / reverse switching actuator, the throttle actuator, the brake actuator, and the like to perform traveling control. The hydraulic pump 21 is controlled to generate hydraulic pressure for driving each functional unit, and the steering control unit 59 causes the front wheel steering angle sensor 25 to operate.
a, steering control (steering amount feedback control) is performed through the front wheel steering hydraulic control valve 22a and the rear wheel steering hydraulic control valve 22b based on the input from the rear wheel steering angle sensor 25b.
The cutting blade control unit 60 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, the front wheel steering hydraulic control valve 22a and the rear wheel steering hydraulic control valve 22b controlled by the steering control unit 59 are connected, and the hydraulic control valves 22a and 22b are respectively 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 59,
The steering control unit 59 controls the steering mechanisms 24a and 24b via the hydraulic pressure control valves 22a and 22b so as to eliminate the deviation between the detected steering angle and 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 to 10, in step S101, the G-DPS is used to measure the preparation position 80 which is the current self position. This position measurement is
Converting D-GPS positioning data such as latitude and longitude (altitude data is also added as necessary) into geodetic system data stored in the work data storage unit 56. Done by. In addition, data conversion to this geodetic system is performed by D-GPS.
It may be performed by the position detection unit 53 or the travel control unit 55.

Then, in step S102, the work data
The terrain data of the first work area 82 is referred to with reference to the data storage unit 56.
Is read out, a route 81 from the measured preparation position 80 to the work start point is generated, and the process proceeds to step S103. Step
In S103, the vehicle is moved to the work start position by executing the autonomous traveling control routine of FIGS. 11 and 12 which will be described later, and in step S104, the cutting blade control hydraulic control valve 26 is opened to open the cutting blade mechanism. The hydraulic pressure is supplied to 9, and the cutting blade 9a is operated to start grass / lawn mowing work.

Then, in step S105, it is checked whether or not it is the first work, and if 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 6
The amount of error from the current position for the route of the first stroke (one column) is calculated.

Then, 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, the process proceeds to step S110, and it is checked whether or not the end point of one stroke (one column) has been reached from the current vehicle position based on the positioning data, for example. Returning to step S106, the grass and lawn mowing work is continued, and when the terminal point is reached, the process proceeds from step S110 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, since it is the first work, the steps S120 to S1
Returning to 05, it is checked again whether or not it is the first operation, and when it is the second operation or later, the process branches from step S105 to step S111, and the cut land C and the uncut land B by the previous grass / lawn mowing work.
The work route is traced along the cut line boundary line L.

That is, in step S111, the vehicle body is laterally shifted by the width of the cutting blade and moved to the next work position. Here, as shown in FIG. 15, the first time (first row) by the D-GPS / dead-reckoning navigation in steps S106 to S110 described above.
When the grass and lawn mowing work is completed by the forward movement F of the vehicle, the steering mechanisms 24a and 24b are controlled based on the data set in advance in the work data storage unit 56, and the forward blade F of the vehicle controls the respective cutting blades 9a. After laterally shifting the lawn mowing work vehicle 1 by the amount obtained by subtracting the preset lawn mowing overlap amount O from the width W according to, the steering mechanism is controlled to move the vehicle body 1a to the grass and lawn mowing work for the first time. The vehicle is set in parallel, the reverse rotation transmission mechanism (not shown) is controlled to bring the vehicle into the reverse R state, and grass and lawn mowing work is started by following along the cut line boundary line L between the already-cut land C and the uncut land B.

Then, in step S112, FIG.
Of the cutting edge boundary detection device 10b on the rear side of the vehicle body 1a is selected at the time of grass / lawn mowing work by the vehicle retreating R, and the rotation angle sensors 14a and 14b of the cutting edge boundary detection device 10b. Based on the signal from, the boundary of the cut by the previous work is detected. Then, in step S113, it is determined whether or not the cut boundary can be detected. When the cut boundary line L between the already-cut land C and the uncut land B is captured, step S1
The process proceeds to step 14, and it is determined whether this process is the first execution. If it is the first execution, the process returns to step S112 without correcting the steering amounts of the front and rear wheel steering mechanisms 24a and 24b.

Here, as described above, since the distance between the sled-shaped plates 13a and 13b of the cut boundary detecting device 10b (10a) is set at the position where the lawn mowing overlap amount O is obtained, after lateral shift, During the first execution of the stroke, the sled-shaped plates 13a and 13b are always positioned so as to straddle the cut boundary line L, and the cut boundary detection device 10b detects the cut boundary, and steps S113 and S114 are performed. The procedure returns to step S112 via.

Then, in step S114, when the routine is executed for the second time in this step, the process proceeds to step S115,
When the routine was executed last time, it was judged whether or not the cut boundary line could be captured.If the cut boundary was also captured last time, the steering amount is not changed and the steering state is maintained as it is. In step S118, it is checked whether or not the one stroke end point has been reached, and if the one stroke end point has not been reached, the flow returns to the aforementioned step S112 to detect the cut mark boundary due to the previous work,
In step S113, it is determined whether the cut boundary has been captured.

As a result, when the cut boundary cannot be captured, the process proceeds from step S113 to step S116, and each steering amount (target steering angle) of the front and rear wheels is corrected according to the previous situation of the cut boundary detection. For example, when the previous routine is executed, the difference between the rotation angles θ1 and θ2 by the rotation angle sensors 14a and 14b of the cut boundary detection device 10b is equal to or larger than the set value, and the cut boundary is detected in the state of θ1 <θ2. Therefore, when θ1 = θ2 this time, the value of θ1 is substantially the same as the previous time, and the value of θ2 becomes smaller than the previous time, the backward moving direction of the vehicle body 1a of the lawnmower work vehicle 1 is the rightward backward direction (the cut area C Direction), and the target steering angle is corrected so that the front and rear wheel steering mechanisms 24a and 24b are operated in the opposite direction by a predetermined amount. Further, when the value of θ1 is smaller than that of the previous time and the value of θ2 is substantially the same as the previous time, it is determined that the backward traveling direction has shifted to the left side of the backward direction (the uncut area B direction), and the target steering angle is similarly set in the opposite direction. Fix it. Further, if the cut boundary has not been captured last time, the target rudder angle correction amount is increased by a predetermined amount in the same direction as the previous correction.

Incidentally, the steps S115 to S116.
When I proceeded to, I was in the state that the target rudder angle was corrected because the cut mark boundary could not be captured the last time the routine was executed.
If this state is maintained when the cut boundary can be captured,
Since the vehicle goes too far in the opposite direction to the cut line B, the target steering angle is corrected in the opposite direction by a predetermined amount.

When the target rudder angle, that is, the steering amount of each of the front and rear wheels is determined, the process proceeds to step S117, and the front wheel steering hydraulic control valve 22a, the rear wheel steering hydraulic control valve 22b, the front wheel hydraulic cylinder 23a, the rear wheel are controlled. The front wheel steering mechanism 24a and the rear wheel steering mechanism 24b are respectively driven via the hydraulic cylinders 23b for control so as to obtain the target steering angles of the front and rear wheels.

Thereafter, in step S118, it is checked whether or not the one stroke end point is reached based on the self-position data, for example, 1
When the end point of the stroke is not reached, the above step S1
Returning to step 12, the contour traveling along the cut boundary is continued, and when the end point of one stroke is reached, the self position is detected in step S119 described above, and the work of one section (work area 82) is completed in step S120. Judge whether or not.

Here, the grass by the retreat R of the lawnmower 1
When the end point of one stroke of lawn mowing is reached and all the work in one section (work area 82) is not completed yet, in step S111 via step S105, as shown in FIG.
The steering mechanisms 24a and 24b are controlled by the data set in advance in the work data accumulating section 56, and in the vehicle retreating state, the lawn mowing overlap amount O from the width W by each cutting blade 9a is controlled.
After laterally shifting the lawnmower 1 by the amount obtained by subtracting, the steering mechanisms are controlled to be in a parallel state with the previous work, the vehicle is set to the forward F state, and the front side of the vehicle body 1a is set in steps S112 to S118. The grass / lawn mowing work is performed by following the cut boundary line L based on the output of the cut boundary detecting device 10a.

Then, steps S105 to S120 are repeated until the work in one section (work area 82) is completed, and the grass / lawn mowing work in one section is continued by the follow-up traveling by forward and backward movement.
When the work of one section is completed, the cutting blade control hydraulic control valve 2
6 is closed to stop the operation of the cutting blade mechanism 9, and step S1
The process proceeds from step 20 to step S121, and it is determined whether or not the work for all the sections has been completed. Here, the next work area 85 is still available.
Since the operation in step S102 has not been completed, the process returns to step S102 described above, and when the route 84 from the work area 82 to the work area 85 is generated by the same procedure, the next operation is performed according to the autonomous traveling control routine of FIGS. 11 and 12. Move to the work area 85 and perform grass and lawn mowing work.

Eventually, when the work of all the sections is completed, the process proceeds from step S121 to step S122, and the work data storage unit 5
6, when the route 87 to the return position 88 is generated,
In step S123, the autonomous traveling control routine of FIGS.
Follow the chin to the return position 88, finish the routine and stop the vehicle.

Next, the autonomous traveling on the routes 81, 84 and 87 by the autonomous traveling control routine shown in FIGS. 11 and 12 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 56. 81, 84, and 87 themselves may be stored in the work data storage unit 56 in advance.

In the self-position measurement by D-GPS, much better accuracy can be obtained as compared with 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 56, and step S2
At 03, it is determined whether or not the positioning accuracy of D-GPS satisfies the set level.

When the D-GPS positioning accuracy satisfies the set level, the process proceeds to step S204, and the moving speed of the lawnmower work vehicle 1 is set to the normal speed stored in the work data storage unit 56. Control so that in step S205, G
When the error amount of the vehicle position is obtained from the position information of the DPS 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 target position is reached, the vehicle is stopped and the routine is exited 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 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 56 so that the dead-reckoning cumulative error caused by the vehicle slip is minimized. S2
At 11, 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 amounts of the front and rear wheels are determined in accordance with the error amount. In step S213, 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 RAM area of the work data storage unit 56 in step S217.

After that, the process proceeds to step S218, the preset data accumulation set time is compared with the data accumulation 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 the D-GPS, and when the set time elapses, the accumulation of the positioning data by the D-GPS ends. Proceed 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 is compared with the target position, and in step S222. , Determine whether the true target position has been reached. As a result, when it is determined that the true target position is reached, when it is determined that the vehicle is stopped and the routine is exited in step S225 described above and the true target position is not reached, When the dead reckoning positioning data is corrected by the average value of the positioning data by D-GPS in step S223, the process proceeds to step S224, a route to the true target position is generated, and the process returns to step S210. The traveling is restarted, and the above processing is repeated until the true target position is reached.

That is, even if 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. If the position accuracy is not obtained, the dead-reckoning navigation is performed to the target position and then stopped, and in the stopped state, the D-GPS positioning data is accumulated for a set time and the average value is taken to obtain the accurate current position. You can know. If the dead-reckoning position is displaced, the dead-reckoning positioning data is corrected by the average value of the set times of the D-GPS positioning data.
It is possible to always perform accurate autonomous driving.

Next, a description will be given of the process of detecting a cut mark boundary in the copying run in the grass / lawn mowing work area. In this cut mark boundary detection processing, in step S301 of FIG.
Based on the data in 0, it is judged whether the lawn mowing vehicle 1 is currently in the forward traveling state or the backward traveling state, and when traveling forward, the process proceeds to step S302, and the rotation of the cut boundary detecting device 10a on the front side of the vehicle body is rotated. The output signals from the angle sensors 14a and 14b are selected, and when the vehicle is moving backward, the process proceeds to step S303, where the rotation angle sensor 14a of the cut boundary detecting device 10b on the rear side of the vehicle body,
The output signal from 14b is selected.

Then, in step S304, data such as grass and lawn mowing height in the target work area is set, and the flow advances to step S305 to select the selected cut boundary detecting device (10a).
Alternatively, by the signals from the respective rotation angle sensors 14a and 14b of 10b), the respective swinging members 12a for suspending the left and right sled-shaped plates 13a and 13b which move up and down according to the height of the grass / lawn cutting.
The rotation angles θ1 and θ2 of 12b are detected.

Then, the process proceeds to step S306, and it is checked whether or not a predetermined time set in advance to give a unit time has passed. If the predetermined time has not passed, the process returns to step S305 and the angle data is returned. Accumulation of. After that, when a predetermined time has elapsed and a predetermined number of angle data are accumulated, the process proceeds from step S306 to step S307, the accumulated left and right angle data is averaged, and set in step S301. Convert to left and right grass / turf height by referring to the data.

Then, from step S307 to step S308, it is checked whether or not there is a difference (corresponding to a step difference in grass / turf height) between the left and right grass / turf heights converted in step S307, If there is no difference equal to or more than the predetermined value, step S3
If it is judged that the cut line L between the already-cut land C and the uncut land B cannot be captured (there is no cut line), the routine goes through 09, and if there is a difference of a predetermined value or more, the step Proceed to S310 to promote the current position as the boundary line between the already-cut land C and the uncut land B, and exit the routine.

Here, each of the cut boundary detecting devices 10a, 10
The sled-shaped plates 13a and 13b of b are rocking members 12a and 1b.
2b measures the length from the upper end to the lower end of each shaft 11a, 1
Since it is set to be approximately the same as or longer than the ground clearance of 1b, it always contacts the upper surface of grass / turf. Therefore, even if the grass / turf length of the uncut land B in the grass / lawn mowing work area is short and the difference between the grass / turf lengths of the already-cut land C and the uncut land B is small, it is possible to surely make the cut boundary. It can be detected.

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 via the wireless communication devices 16 and 36 in step S402. , And proceeds to step S403 to obtain the differential information from the fixed station 30 by wireless data communication.

Then, when the operation proceeds to 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 vehicle position. Then, the positioning information is transmitted to the travel control unit 5
When it is sent to step 5, 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, in the grass and lawn mowing work, the uncut land B is always on the right side in the forward direction of the lawn mowing vehicle 1 (left side in the backward direction) with respect to the already-cut land C, and the cut mark boundary is set. Although the detection devices 10a and 10b are installed on the lower part of the vehicle body on the left side in the forward direction, the uncut land B may be on the left side in the forward direction (right side in the reverse direction) with respect to the already-cut land C. In this case, the cut boundary detecting device is installed on the lower right side of the vehicle body in the forward direction. Further, in order to deal with both the left-right relationship between the already-cut land C and the uncut land B, the cut mark boundary detection devices may be installed respectively on the right side and the left side in the forward direction under the vehicle body.

Further, in this embodiment, movement from the preparation position 80 to the work area 82, movement between the work areas 82 and 85, work traveling of the first one stroke (first column) in each work area 82 and 85, In addition, the movement from the work area 85 to the return position 88 is performed by D-GPS or dead reckoning by unmanned autonomous driving, but these may be driven by manned vehicles.

Further, as shown in FIG. 17, the grass / lawn mowing work may be performed in the grass / lawn mowing area in a circular manner (in a spiral shape). In this case, the grass / lawn mowing operation on the outermost first lap is performed by D-. GP
S or dead reckoning is carried out, and the second and subsequent laps are carried out by following the cut boundary. In this case, it is possible to deal only with the cut boundary detection device 10a on the front side in the vehicle traveling direction, the cut boundary detection device 10b on the rear side can be omitted, and the main control routine described above can be omitted. In step S110 in step S110, it is determined whether or not the grass / lawn mowing work has completed one lap, so that it is determined as the end point of one stroke, and by following the circular shape, steps S111 and S118 are not necessary, and the cut boundary is always maintained. Since only the detection device 10a is used, steps S301 to S303 in the cut boundary detection routine are unnecessary.

Furthermore, the cut boundary detection devices 10a and 10b
The mounting position of the cutting blade mechanism is not limited to this embodiment, and may be provided before and after the cutting blade mechanism 9 in the lower part of the vehicle body. For example, the deck of the cutting blade mechanism 9 or the frame fixed to the cutting blade mechanism 9. It may be attached to.

[0079]

As described above, according to the cut boundary detecting device of the first aspect, the sled-like plates located in the left-right direction of the vehicle body move up and down depending on the height of the grass and the lawn, respectively. Since each shaft supported at the lower part rotates via the swing member, and the rotation angle of each shaft is detected by the rotation angle sensor, the difference between the rotation angles causes the cut marks on the cut and uncut land. Boundary can be discriminated, and unlike the previous example, which detects the cut boundary by the optical system, it surely cuts the uncut and uncut land on the work site without being affected by the environment of use such as dust and mud. It is possible to detect the cut boundary with the ground. Further, since the rocking member between the sled-shaped plate and the shaft is set to have a length substantially equal to or higher than the ground height of each shaft, when the grass / turf height at the work site is low. The sledge-shaped plate surely contacts the grass / turf, and even if there is little difference in the grass / turf length between the cut and uncut areas, the cut boundary between the cut and uncut areas can be reliably detected. .

Further, according to the autonomous traveling work vehicle of claim 2, sled-like plates positioned in parallel in the left-right direction of the vehicle body depending on the length of the grass / turf are respectively moved up and down as the vehicle advances, and are placed at the bottom of the vehicle body. Each shaft rotatably supported rotates via the swing member, and a signal corresponding to the rotation angle of each shaft is output from the rotation angle sensor to the control device. When the difference is a certain value or more, the position is used as the position data of the cut mark boundary between the already-cut land and the uncut land in the grass / lawn mowing work area, and the steering mechanism is controlled based on this position data. Autonomous traveling along the trace boundary makes it possible to reliably drive autonomously along the boundary line between the cut and uncut areas without being affected by the operating environment. The workability of grass and lawn cutting can be improved.

[Brief description of drawings]

FIG. 1 is a lawnmower equipped with a D-GPS mobile station and D-
Explanatory drawing showing fixed station for GPS

FIG. 2 is a plan view showing a mounting position relationship between a cutting blade mechanism and a cut boundary detecting device in a lawn mowing vehicle.

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

FIG. 4 is an explanatory diagram showing the operation of the cut boundary detecting device.

FIG. 5 is a block diagram of a control device.

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: Flow chart of main control routine

FIG. 9: Flow chart of main control routine (continued)

FIG. 10: Flow chart of main control routine (continued)

FIG. 11: Flow chart of autonomous traveling control routine

[Fig. 12] Flow chart of autonomous driving control routine (continued)

FIG. 13: Flow chart of cut edge detection routine

FIG. 14 is a flowchart of a D-GPS wireless communication routine.
To

FIG. 15 is an explanatory view showing a vehicle shift state at the end of one stroke by grass / lawn mowing work.

FIG. 16 is an explanatory diagram showing a vehicle shift state at the end of one stroke by grass / lawn mowing work.

[Fig. 17] An explanatory diagram of a case where grass and lawn mowing work is performed on a ring mowing

[Explanation of symbols]

 1 Lawn mowing work vehicle (autonomous traveling work vehicle) 1a Vehicle body 10a, 10b Mow boundary detection device 11a, 11b Shaft 12a, 12b Swing member 13a, 13b Sled-like plate 14a, 14b Rotation angle sensor 24a, 24b Steering mechanism 50 Control apparatus

Claims (2)

[Claims] 1. A swinging member in which a plurality of shafts rotatably supported on a lower portion of a vehicle body are arranged side by side in the left-right direction of the vehicle body, and the plurality of shafts have a length substantially the same as or higher than the ground clearance of each shaft. Are suspended and fixed, a sled-like plate is rotatably suspended on the lower end of each of the swing members, and a rotation angle sensor for detecting the rotation angle of each of the shafts is provided. Detection device. 2. A plurality of shafts that are rotatably supported are arranged side by side in the left-right direction of the vehicle body in the lower part of the body of the autonomously-operated work vehicle, and the plurality of shafts have a length substantially the same as the ground clearance of each shaft or that. Each of the rotation angle sensors has a rotation angle sensor for suspending and fixing a swinging member longer than the above, a plate rotatably suspended on a lower end portion of each of the swinging members, and detecting a rotation angle of each shaft. When the difference in the rotation angle of each axis is more than a certain value, the position is detected as the boundary between the cut and uncut areas in the grass and lawn mowing work area. An autonomous traveling work vehicle comprising a control device for controlling a steering mechanism based on the position data of the above.