JPH0829005B2 - Self-driving lawnmower - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a lateral position of a vehicle body with respect to a boundary in order to automatically drive a lawnmower along a boundary between uncut and already cut land. The present invention relates to an automatic traveling lawnmower work vehicle equipped with a boundary detection device for discriminating between.

[Conventional technology]

In the above-mentioned automatic traveling lawnmower work vehicle of the type described above, conventionally, for example, as shown in FIG. 7, two photointerrupter type lawn presence / absence detection sensors (S ₁ ) and (S ₂ ) form one set. In the state in which the steering control sensor is configured and the vehicle body (V) is properly along the boundary (L) between the uncut land (B) and the already cut land (C), the presence or absence of two grasses The sensors are arranged side by side in the lateral direction of the vehicle body so that the boundary (L) is located between the detection sensors (S ₁ ) and (S ₂ ). In other words, when the sensor (S ₂ ) on the uncut side detects the presence of uncut grass and the sensor (S ₁ ) on the cut side does not detect uncut grass, the vehicle body (V) with respect to the boundary (L). 2)
It is judged that the vehicle body (V) is located on the uncut side with respect to the boundary (L) when both the grass presence detection sensors (S ₁ ) and (S ₂ ) detect uncut grass, and , The state in which both uncut grasses are not detected is determined to be on the cut side (see Japanese Utility Model Laid-Open No. 58-125912).

Since the steering control sensor may be run with the boundary located on the left side of the vehicle body or with the boundary located on the right side, two sets of left and right are provided. Become.

By the way, in the case where a plurality of parallel working strokes are reciprocated by repeatedly moving forward and backward for each stroke, one set of steering control consisting of two pairs of grass presence detection sensors is used. Two sets of sensors will be provided on the front and rear sides of the vehicle body.

[Problems to be Solved by the Invention]

In the above conventional configuration, since one set of steering control sensors is composed of two turf presence / absence detection sensors, for example, when the boundaries are located on the left and right sides of the vehicle body, the forward and backward movements are repeated. In order to correspond to each case of automatic traveling, a total of eight pairs of turf presence / absence detection sensors are used, which is disadvantageous in that the device configuration becomes complicated and expensive.

The present invention has been made in view of the above circumstances,
An object of the present invention is to make it possible to accurately determine the position of the vehicle body with respect to the boundary and appropriately correct the positional deviation of the vehicle body with respect to the boundary while reducing the number of installed grass presence detection sensors.

[Means for solving the problem]

The characteristic configuration of the automatic traveling lawnmower according to the present invention is
A sensor for detecting the presence or absence of grass is provided at one end of the vehicle body in the lateral width direction, near the boundary.
One sensor is provided at the end of the gutter away from the boundary in the widthwise direction of the vehicle body, and one of the two sensors for detecting the presence or absence of grass has a boundary between the uncut land and the already cut land as the vehicle body. When the vehicle body is located on the left side of the vehicle body, it is provided on the left side of the vehicle body so as to be located on the boundary in a state where the vehicle body is properly along the boundary, and the other sensor is When the boundary is located on the right side of the vehicle body, the vehicle body is provided on the right side of the vehicle body so as to be positioned on the boundary in a state where the vehicle body is properly along the boundary, and, A storage unit that stores a set number of detection states of each of the sensors each time the vehicle travels a set distance or a set time elapses, and a sensor on the uncut ground based on the storage information of the storage unit. The number of times uncut grass was detected by the A discriminating means for discriminating the position of the vehicle body in the lateral width direction with respect to the boundary based on the ratio of the number of times the above sensor detects uncut grass or the size of the difference is provided, and the discriminating result obtained by the discriminating means. Based on the above, steering control means is provided for steering control so as to correct the position of the vehicle body in the lateral width direction with respect to the boundary to an appropriate position.

[Action]

Since grass does not grow continuously, the grass presence detection sensor randomly repeats the state of detecting the presence of uncut grass and the state of not detecting it as the vehicle travels. Paying attention to the amount of uncut grass in the lateral direction of the vehicle body while running for a set distance or for a set time, the amount of uncut grass on the boundary between uncut land and already cut land is
It can be considered to be about half the amount of uncut grass on uncut ground. This is because traveling on the boundary approximates to traveling while detecting uncut ground and already cut ground alternately. Therefore, when the vehicle body is traveling properly along the boundary,
The sensor on the uncut ground always detects uncut grass, but the sensor on the boundary increases the number of times the uncut grass is detected as the vehicle body shifts to the uncut side with respect to the boundary. ,
In addition, the number of times the presence of uncut grass is detected decreases with the shift to the already-cut area.

Further, the ratio of each of the two sensors detecting uncut grass with respect to the entire detection result during traveling for the set distance or for the set time is higher as the lawn is denser, depending on the density of the lawn. Will be. That is, when the density of turf is high, the rate of detecting uncut grass in the uncut grass is higher than that in the rough area, and the rate of detecting uncut grass in the cut grass is also rough. It will be higher than that.

Therefore, each time the vehicle body travels for a set distance or each time a set time elapses, the detected state of each of the two sensors is stored separately, and the detected state of the set number stored in association with each sensor is stored. Among them, if the ratio or the difference between the number of times the sensor on the uncut ground detects uncut grass and the number of times the sensor on the boundary detects uncut grass, regardless of the density of the grass, Compared with the number of times obtained by the sensor, the number of times obtained by the sensor on the boundary greatly differs depending on whether the sensor on the boundary is on uncut ground or on already cut ground. Since the ratio of the number of times the uncut grass is detected or the size of the difference is different depending on the deviation of the cut grass and the deviation toward the cut land, the position in the lateral width direction with respect to the boundary should be accurately determined. And the car based on the discrimination result There is for steering control such well along the boundary.

〔The invention's effect〕

As a result, it is possible to accurately determine the position of the vehicle body with respect to the boundary and maintain the position of the vehicle body with respect to the boundary, while reducing the number of installed grass presence detection sensors.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 5, a mower (2) is mounted on the lower abdomen of a vehicle body (V) having a pair of left and right front wheels (1F) and a pair of left and right rear wheels (1R), so that weeds, grass, etc. A work vehicle for lawn mowing used for mowing work is configured.

In the figure, (3) is a steering handle for boarding and manipulating.

However, each of the front wheels (1F) and the rear wheels (1R) is configured as a so-called four-wheel steering type and four-wheel drive type so as to function as both steering wheels and driving wheels.

Then, as shown in FIG. 6, a plurality of work steps arranged in the lateral direction of the vehicle body are defined as one work step including a section from one side of the uncut land (B) as a square unprocessed work area to the opposite side. In each work stroke, the vehicle automatically travels along the boundary (L) between the uncut land (B) and the already cut land (C) as the processed work land, and reaches the end of one work stroke. By repeating the turn of moving to the starting end of the next work stroke adjacent to the work stroke, each work stroke is reciprocated to automatically perform the lawn mowing work within a predetermined range.

However, in the present embodiment, as will be described later, the automatic work starts immediately after the first work stroke without dividing the planned work area into the rectangular uncut land (B) surrounded by the already cut land (C). The work distance can be started, and the reference distance for the work stroke is automatically set based on the travel distance in the first work stroke, and each time the work vehicle travels the set reference distance, I am trying to turn automatically toward the work process.

Further, the work vehicle is configured to travel back and forth through a plurality of work strokes while switching between forward and backward movements for each stroke. Therefore, the turn for moving to the next work stroke is accompanied by traveling the reference distance. In the forward traveling state or the backward traveling state, the vehicle body is not changed, and the vehicle is moved toward the next work stroke side by side, and then the forward and backward movements are switched.

Further, the work vehicle is configured to be able to be driven not only by automatic running but also by boarding operation in which the work vehicle is boarded and artificially driven.

Then, as will be described later, the start and stop of the automatic traveling and the start of the turn in the first work stroke can be remotely instructed from outside the vehicle body.

Explaining the control configuration of the work vehicle, as shown in FIG. 1, steering hydraulic cylinders (4F) and (4R) for individually operating the front and rear wheels (1F) and (1R), respectively, Control valves (5F), (5R), hydraulic continuously variable transmission (6) that can be switched between forward and reverse and forward and backward, a speed change motor (7) for speed change operation, and various travel controls stored in advance A control device (8) using a microcomputer for operating the control valves (5F), (5R) and the speed change motor (7), based on information and detection information of various sensors described later, start / stop of automatic traveling, And a transmitter (9) for instructing each start of a turn, and a receiver (10) for receiving instruction information from the transmitter (9) and inputting the instruction information to the control device (8). There is.

In the figure, (E) is an engine for driving the front and rear wheels (1F), (1R) and the mower (2), and is linked to the transmission (6). (11) is a speed change pedal for artificially operating the speed change device (6) during boarding operation, (12) is a speed change arm of the speed change device (6), and includes the speed change motor (7) and the speed change motor (7). Speed change pedal (1
The gear shift motor (7) and the gear shift pedal (11) are interlockingly connected so that the gear shift operation can be performed by any one of 1).

(13) is a clutch mechanism for connecting and disconnecting the transmission motor (7) to the transmission arm (12) and is operated by a manual operation type clutch lever (14) (see FIG. 5). It is like this. That is, the clutch lever (14) is operated to disengage during the boarding maneuver to disconnect the linkage between the speed change motor (7) and the speed change device (6), and to be turned on during the automatic running to operate the speed change motor (7).
And the transmission (6) are linked.

Further, (SW) is a clutch switch for detecting the operation state of the clutch lever (14). In other words, the control device (8) determines whether it is a boarding maneuver or an automatic running based on the detection information of the clutch switch (SW).

By the way, the front and rear wheels (1F) and (1R) are configured to function as steering wheels as well as driving wheels as shown in FIG. , (1R)
Parallel steering type that steers in the same phase, four-wheel steering type that steers in the opposite phase, front wheels (1F) or rear wheels (1
It is possible to select and use two types of steering types, a two-wheel steering type that steers only R). Although not shown, the steering type to be used is artificially selected during boarding operation, and automatically switched based on the detection information of various sensors described later during automatic traveling.

Next, various sensors mounted on the work vehicle will be described.

As shown in FIG. 4 and FIG. 5, a scanning sensor (S ₁ ) as a grass presence / absence detecting sensor for detecting the presence / absence of uncut grass,
(S ₂ ) is provided at the tip of each of the four sensor support arms (15) extending from both ends of the working range of the mower (2) in both the front and rear directions of the vehicle body. ing.

However, the vehicle body (V) 2 pieces of the scanning sensor in a state located at the left and right respectively with respect to _{(S 1), (S 2} ) one of (S _1), the boundary (L) is the body ( When the vehicle body (V) is located on the left side of the vehicle body (V), the vehicle body (V) is located on the boundary (L) while being properly aligned with the boundary (L). ) Is provided on the left side, and the other (S ₂ ) is such that the boundary (L) is the vehicle body (V).
When the vehicle body (V) is positioned on the right side of the vehicle body (V), the vehicle body (V) is positioned on the boundary (L) while being properly aligned with the boundary (L).
It is provided on the right side of.

Each of the scanning sensors (S ₁ ) and (S ₂ ) is provided with a pair of a light projecting section and a light receiving section that are arranged so as to face each other in the lateral direction of the vehicle body, and is configured as a so-called photo interrupter type. The state where the light traveling from the light projecting portion to the light receiving portion is blocked by the uncut grass is present, that is, the uncut grass (B).
Is detected, and the state in which the light is not blocked is detected as the absence of uncut grass, that is, the cut land (C).

Then, during automatic traveling, two of the four scanning sensors provided at the front and rear ends of the vehicle body, which are located on the front side with respect to the traveling direction of the vehicle body, are used to detect the vehicle body (V) with respect to the boundary (L). It is determined whether the position in the width direction is shifted to the left or right.

The configuration for determining the lateral width direction position of the vehicle body (V) with respect to the boundary (L) using the _two scanning sensors (S ₁ ) and (S ₂ ) on the front side of traveling will be described later. .

As shown in FIGS. 1 and 5, in order to detect the inclination of the vehicle body (V) with respect to the reference azimuth set based on the length direction of the work stroke, that is, the length direction of the boundary (L), An orientation sensor (S ₃ ) using a geomagnetic sensor is attached to the rear end of the vehicle body.

As shown in FIG. 1, there is provided a rotation speed sensor (S ₄ ) that is rotationally driven by the output of the transmission (6) and outputs a set number of pulse signals per unit rotation speed. Is configured to detect the traveling distance of the vehicle body (V).

Further, a potentiometer (R ₀ ) for detecting a target steering angle by the steering handle (3), potentiometers (R ₁ ), (R ₂ ) for detecting steering angles of the front and rear wheels (1F), (1R), respectively, Further, a vehicle speed detecting potentiometer (R ₃ ) is provided, which indirectly detects the forward / backward switching state and the vehicle speed in forward / reverse traveling by detecting the operating state of the transmission (6). .

That is, using the control device (8), based on the detection information of the various sensors and various control information stored and set in advance, as the vehicle body (V) reaches the end portion of each work stroke, Travel control means for controlling to automatically travel along each work stroke while automatically turning toward the next work stroke, and two scanning sensors (S ₁ ) on the front side of the travel every time the vehicle travels a set distance. , (S ₂ ) each store the number of times each of the uncut grasses has been detected by a set number, and based on the storage information of the storage means (100), the above-mentioned information for the boundary (L) is stored. Each of the discriminating means (101) for discriminating the lateral position of the vehicle body (V) and the steering control means for steering the vehicle body (V) based on the discrimination result by the discriminating means (101) are configured. Will be.

Next, the control operation for automatically traveling the work vehicle along the work stroke will be described in detail based on the flowchart shown in FIG.

First, the clutch lever (13) is turned on and off, the transmission (6) and the transmission motor (7) are linked, and the transmitter (9) is instructed to start automatic traveling. .

When the receiver (10) receives an instruction to start traveling, the control device (8) determines the orientation detected by the orientation sensor (S ₃ ), that is, the vehicle body orientation at the time of traveling start, in a plurality of work strokes. After setting and storing the respective reference directions, the transmission (6) is operated to start traveling so that the vehicle body (V) travels at the set vehicle speed.

Then, the as-detected orientation by the orientation sensor (S ₃₎ is maintained at the set dead zone with respect to the reference azimuth, will steering control based on the orientation detection information of the sensor (S _3).

That is, as described above, when the work is started without dividing the planned work range into the rectangular uncut land (B), the uncut land (B) is not included in the first work process (first process). Since the boundary (L) with the already cut land (C) is not formed,
Since it is not possible to determine the deviation in the vehicle lateral direction with respect to the boundary (L) using the detection information of the scanning sensors (S ₁ ) and (S ₂ ), in the first stroke, the direction sensor (S ₃ ) The vehicle is automatically driven using only the detected information.

However, as shown in FIG. 6, in each work step after the first step, the uncut land (B) and the already-cut land (C) are separated from each other along with the progress of the cutting work by the mower (2). Boundary (L)
Is formed, so as to automatically run in the direction of each work stroke while preventing uncut residue,
Wherein said scanning sensor and the azimuth sensor _{(S 3) (S 1)} , (S 2)
Steering control will be performed using both of the detection information of.

After the start of traveling, it is determined whether or not a turn start instruction is received, based on the reception information of the receiver (10) in the first stroke, and the number of revolutions is increased as the turn start instruction is received. A turn control for moving to the next work stroke after setting and storing the detected travel distance from the start of travel in each work stroke by the sensor (S ₄ ) to the time when the instruction to start the turn is received as the reference distance. Will be started.

Then, after turning toward the next work stroke, the traveling distance detected by the rotation speed sensor (S ₄ ) reaches the set reference distance, or the receiver (10) As described above, detection of both of the scanning sensors (S ₁ ) and (S ₂ ) and the direction sensor (S ₃ ) is performed so that the vehicle automatically travels along each work stroke until the worker receives an instruction to finish the work. The steering control is performed based on the information, and the vehicle body (V) is automatically driven along each work stroke.

When the mileage reaches the reference distance for each work stroke, the driver will turn toward the next work stroke, and when the instruction to finish the work is received, stop traveling and finish the work. become.

Basically, if the steering control is added,
When the azimuth detected by the azimuth sensor (S ₃ ) is out of the set dead zone with respect to the reference azimuth, a target steering angle for azimuth correction is set according to the deviation between the detected azimuth and the reference azimuth. Then, the direction of the vehicle body (V) is corrected by the two-wheel steering system that steers only the front wheel (1F) or the rear wheel (1R) that is on the front side with respect to the traveling direction of the vehicle body. When it is determined based on the detection information of the scanning sensors (S ₁ ) and (S ₂ ) that the displacement is with respect to the boundary (L), the target steering angle for scanning correction is determined according to the displacement direction. Is set, and the position in the lateral width direction with respect to the boundary (L) is corrected by the parallel steering type in which the front and rear wheels (1F) and (1R) are steered in the same phase.

However, although not shown, when both the orientation of the vehicle body (V) with respect to the reference azimuth and the position in the width direction with respect to the boundary (L) are deviated, the inclination with respect to the reference azimuth and the boundary (L) The target steering angles of the front and rear wheels (1F) and (1R) are set to the target steering angle for the azimuth correction and the target steering for the tracking correction so that both positions can be corrected simultaneously. The angle and the front and rear are respectively set to values added separately so that the steering angles of the front and rear wheels (1F) and (1R) are automatically different.

Next, based on the flowchart shown in FIG. 3, a configuration for determining the position of the vehicle body (V) with respect to the boundary (L) based on the detection information of the scanning sensors (S ₁ ) and (S ₂ ), Further, steering control (copy control) executed based on the determination information will be described in detail.

However, in the following description, as shown in FIGS. 4 to 6, the right side scanning sensor (S ₂ ) is the boundary (L).
It shall be run in the state of being located on the side.

That is, each time the vehicle body (V) travels a set distance (5 cm), the grass for reading and storing the detection data of each of the _two scanning sensors (S ₁ ) and (S ₂ ) located on the front side of the travel. After performing the process of updating the density calculation data, it is determined whether or not the stored data is the set number (20).

Then, when the stored data is the set number (20), the lawn density on both the boundary side and the uncut side is calculated separately based on the stored data, and the lawn density on the boundary side is calculated. , And the grass density on the boundary side with respect to the uncut side is calculated by dividing by the uncut side grass density.

To explain the calculation of the lawn density, the higher the lawn density is, the more the number of detecting the presence of uncut grass in the detection data stored for the set number is increased, and thus the number is stored. A value obtained by dividing the number of times each of the scanning sensors (S ₁ ) and (S ₂ ) detected uncut grass by the set number in the detection data for the set number is used as the lawn density.

However, until the stored data reaches the set number (20), the lawn density ratio (r) is provisionally set to 50% corresponding to a state in which there is no deviation from the boundary (L). I am doing it. After the stored data reaches the set number (20), the oldest data is erased every time new detection data is read, and the set number (20) is always used. The grass density ratio (r) is calculated every time the vehicle travels a set distance (5 cm).

Next, based on the value of the grass density ratio (r), it is determined whether the position of the vehicle body (V) in the lateral width direction with respect to the boundary (L) is deviated to the uncut side or to the cut side. , And when it is determined that it is shifted to the uncut side or the already cut side,
By the steering control means, the target steering angle is set so as to move in parallel in the direction in which the deviation is corrected, and the steering operation is performed in the parallel steering type.

That is, when the lawn density ratio (r) is greater than 80%, it is determined that the vehicle body (V) is displaced to the uncut side with respect to the boundary (L), and the cut side ( When steering is performed in the OUT direction) and the lawn density ratio (r) is less than 20%, the vehicle body (V) is displaced to the cut side with respect to the boundary (L). If it is determined, the steering operation is performed toward the uncut side (IN direction), and when the lawn density ratio (r) is between 20% and 80%, the vehicle body (V) is at the boundary. It is determined that the front and rear wheels (1F) and (1R) are in the steering neutral state corresponding to the straight traveling state by judging that the front and rear wheels (1F) and (1R) are properly aligned with respect to the (L).

That is, in order to calculate the turf density, the detection data of each of the _two left and right scanning sensors (S ₁ ) and (S ₂ ) is the oldest every time the vehicle body (V) travels a set distance (5 cm). The process of updating the grass density calculation data, which stores new data while erasing the data, detects the detection states of both sensors (S ₁ ) and (S ₂ ) each time the vehicle body (V) travels a set distance. It corresponds to the storage means (100) for storing the set number of pieces, and based on the size of the turf density ratio (r),
The process for determining whether the lateral position of the vehicle body (V) with respect to the boundary (L) is shifted to the uncut side or to the cut side is performed by the uncut grass sensor (S ₁ ) Discriminating means for discriminating the lateral position of the vehicle body (V) with respect to the boundary (L) based on the size of the ratio between the number of times the vehicle is detected and the number of times the sensor (S ₂ ) on the boundary detects uncut grass. (Ten
It corresponds to 1). Further, the control device (8) is also provided with steering control means for performing steering control of the vehicle body (V) based on the discrimination result of the discrimination means (101), and the steering valve controls the control valve (5F). , (5R) control signal is output.

To explain the turn control, as described above, since the vehicle body (V) repeats forward and backward movements to reciprocate in each work stroke, the parallel steering type is used, for example, the maximum turning is performed. By moving a set distance at the corner to move it to the next work stroke side by side, the forward / backward movement and the copy sensor (S ₁ ) to be used,
(S ₂ ) will be switched back and forth.

[Another embodiment]

In the above embodiment, the storage means (100) is replaced by the copy sensor (S
_Although the detection data of ₁ ) and (S ₂ ) is stored every time the vehicle body (V) travels a set distance (5 cm), the detection data may be stored at each set time. . Further, after storing the set number of data, instead of erasing the oldest data and storing new data, after determining the position with respect to the boundary (L) based on the stored information of the set number, all stored data are stored. May be deleted and a set number of data may be newly stored, and the storage means (10
Various modifications can be made to the specific configuration of (0).

Further, in the above embodiment, the determining means (101) calculates the grass density on the uncut side and the grass density on the boundary side on the basis of the storage information of the storage means (100), and calculates the grass density of the grass density. Ratio (r)
Although the case where the position with respect to the boundary (L) is determined based on the above is illustrated, the determination may be performed based on the difference between the lawn density on the uncut side and the lawn density on the boundary side.

Further, in the above-mentioned embodiment, the case where only the deviation direction with respect to the boundary (L) is discriminated is illustrated, but the deviation is quantitatively discriminated according to the ratio (r) of the grass density and the magnitude of the difference. The target steering angle may be set according to the discriminated size, and the specific configuration of the discriminating means (101) and the usage form of the discriminant information can be variously changed.

Further, in the above-described embodiment, the case where the azimuth correction is performed by the two-wheel steering type is illustrated, but it may be performed by the four-wheel steering type.

Further, in the above embodiment, the case where the steering control is performed while also performing the azimuth correction is illustrated, but the steering control may be performed without the azimuth correction. However, in that case, it is advisable to perform the above-mentioned copying correction by steering only the front wheel (1F) or the rear wheel (1R) that is on the front side with respect to the traveling direction of the vehicle body.

Further, in the above-mentioned embodiment, the case where the vehicle is made to travel forward and backward by repeating forward and backward movements is illustrated. However, the vehicle is traveled in a form in which the traveling direction is reversed by 180 degrees, or uncut land adjacent to the already cut land (C) ( The vehicle may be driven in such a manner that each side circulates along the outer peripheral portion of B), and the specific configuration of each portion such as the traveling control means for automatically traveling the work vehicle can be variously changed.

However, in the case of traveling in a manner in which the traveling direction is reversed by 180 degrees, each time the traveling direction is reversed, the sensor (S ₁ ) located on the boundary of the _two scanning sensors (S ₂ ) (S ₂ ) The relationship between S ₂ ) and the sensor (S ₁ ) located on the uncut ground is interchanged to make a distinction.

It should be noted that reference numerals are added to the claims for convenience of comparison with the drawings, but the present invention is not limited to the structures of the accompanying drawings by the entry.

[Brief description of drawings]

The drawings show an embodiment of an automatic traveling lawn mowing work vehicle according to the present invention. Fig. 1 is a block diagram of a control configuration, Fig. 2 is a flow chart of traveling control, Fig. 3 is a flow chart of steering control, and Fig. 4 is shown. Is a front view of the work vehicle, FIG. 5 is a plan view of the same, and FIG.
The figure is an illustration of the work site. FIG. 7 is a front view of the conventional example. (B) ... uncut land, (C) ... already cut land, (L) ... boundary,
(V) ... vehicle body, (S ₁ ), (S ₂ ) ... grass presence detection sensor,
(100) ... storage means, (101) ... discrimination means.

Claims (2)

[Claims] 1. A turf presence / absence detecting sensor (S ₁ ) and (S ₂ ) for detecting the presence or absence of turf is provided at one end of a vehicle body (V) at a position near a boundary in the lateral width direction. , One of the two grass presence detection sensors (S ₁ ) and (S ₂ ) is provided at the end of the gutter away from the boundary of the vehicle body (V) in the width direction. S ₁ ) means that when the boundary (L) between the uncut land (B) and the already-cut land (C) is located on the left side of the vehicle body (V), the vehicle body (V) is opposed to the boundary (L). Is provided on the left side of the vehicle body (V) so as to be positioned on the boundary (L) in a state in which the sensor (S ₂ ) is properly aligned with the boundary (L). Is located on the right side of the vehicle body (V), the vehicle body (V) is located on the boundary (L) while being properly aligned with the boundary (L). On purpose so as to the vehicle body (V)
Of the sensors (S ₁ ) and (S ₂ ) which are provided on the right side of the vehicle and each time the vehicle body (V) travels a set distance or when a set time elapses. Based on the storage means (100) and the storage information of the storage means (100), the number of times the sensor (S ₁ or S ₂ ) on the uncut ground detects uncut grass and the sensor on the boundary (S ₂ or And a discriminating means (101) for discriminating the lateral position of the vehicle body (V) with respect to the boundary (L) based on the ratio of the number of times S ₁ ) has detected uncut grass or the size of the difference. The discrimination means (101)
An automatic traveling lawnmower provided with steering control means for steering control so as to correct the lateral position of the vehicle body (V) with respect to the boundary (L) to an appropriate position based on the discrimination result obtained in (1). Work vehicle. 2. The automatic traveling lawnmower vehicle according to claim 1, wherein the lawn presence / absence detecting sensors (S ₁ ) and (S ₂ ) are configured as a photo interrupter type.