JPH0678603A - Apparatus for detecting border of grass mower - Google Patents

Abstract

PURPOSE:To keep the border-detection accuracy and prevent the malfunction and damage of a moving operation means by preventing the error in the detection of the presence of grass caused by cut grass, etc., attached to the mower. CONSTITUTION:This apparatus is provided with a grass detection means 22 to detect the presence of grass at prescribed intervals along the lateral direction of the machine body by grass-detection sensors S1, S2, S3, S4 to detect the presence of grass by projecting a grass-detection signal on the grass in front of the machine body and a border-judging means 100 to determine the border between the untreated ground A and the treated ground B based on the information transmitted from the grass detection means 22. The grass-detection means 22 is positioned above a grass-height restriction means 11 placed at the front part of the machine body to restrict the upward protrusion of grass by guiding the grass downward and is placed behind the front end of the height-restriction means. The grass detection means 22 is provided with a moving operation means 23 to move the grass-detection sensors S1, S2, S3, S4 along the lateral direction of the machine body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a grass presence / absence detection sensor for projecting a grass presence / absence detection signal onto grass on the front side of a vehicle body to detect the presence / absence of the grass at predetermined intervals along the lateral direction of the vehicle body. The present invention relates to a boundary detection device for a grass mower provided with a grass presence / absence detection means for detecting the presence / absence and a boundary discrimination means for discriminating a boundary between an unprocessed work site and a processed work site based on information of the grass presence / absence detection means. .

[0002]

2. Description of the Related Art A boundary detecting device for a grass mower of this type is used, for example, in a self-propelled lawnmower work vehicle for performing the work of cutting grass as grass without manpower. In addition, for example, a grass presence detection sensor composed of a reflection type photo interrupter projects the grass light on the front side of the vehicle while changing the projection direction of the light signal for presence detection, along the vehicle width direction, and the reflected light The presence of grass was detected with grass, while the absence of reflected light was detected with grass. Then, from the detection result of the grass presence state at predetermined intervals along the lateral direction of the vehicle body, for example, the position with grass closest to the processed work site in the unprocessed work site and the most unprocessed work in the processed work site. An intermediate position between the grassless position located on the ground side and the unprocessed work site is treated as a boundary between the unprocessed work site and the processed work site.

However, conventionally, the grass presence / absence detecting sensor is configured to detect the presence / absence of the grass in a state of being thrust into the grass on the front side of the vehicle body.

[0004]

Therefore, in the above-mentioned prior art, cut grass or the like may adhere to the detection surface of the grass presence / absence detection sensor, and in that case, the grass presence / absence detection signal is always on, that is, grass is present. Or always off, i.e. grassless. Then, in the former case, it is erroneously detected that the front side of the vehicle body is the unprocessed work site, that is, the boundary is not located on the front side of the vehicle body and is located further away from the processed work site side. As a result, if the steering control is performed based on this boundary detection information, it is possible to displace more than necessary to the processed work site to perform effective mowing work, while in the latter case, the front side of the vehicle body has all been processed. As a result of erroneous detection that it is the work site, that is, the boundary is not on the front side of the vehicle body and is located on the unprocessed work site side than that, steering control is performed based on this boundary detection information. If this happens, the position of the unprocessed work will be displaced more than necessary, and uncut areas will be left behind. Eventually, in both cases, the vehicle body may jump out of the work site and come into contact with other objects, possibly damaging the vehicle body or the like.

Further, in the case of a configuration in which the detection position of the grass presence detection sensor at predetermined intervals along the lateral direction of the vehicle body is changed by a mechanical moving mechanism operated by a driving force from a motor or the like, Not only does the movement of the sensor not operate normally due to an increase in the operating load of the above mechanical movement mechanism due to the attachment of cut grass, etc., but the mechanical mechanism or motor may be damaged when the load is excessive. It was

Therefore, in order to avoid these problems, when the grass presence detection signal is constantly on or off for a certain period of time or more, it is regarded as a detection abnormality and the traveling is stopped and the sensor is cleaned. The automatic driving is started again from. However, in this case, since the work is interrupted each time the detection abnormality of the sensor occurs, another problem that the work efficiency is lowered occurs.

The present invention has been made in view of the above circumstances, and an object thereof is to prevent erroneous detection of grass presence detection due to adhesion of cut grass or the like and ensure boundary detection accuracy. At the same time, another object of the present invention is to obtain a boundary detection device for a mower, which avoids malfunction or damage of the moving operation means for detecting the presence or absence of grass due to tangling of cut grass or the like.

[0008]

According to a first characteristic configuration of a boundary detecting device for a mower according to the present invention, the grass height limiting means for guiding the grass downward and limiting the upward projection of the grass is a machine body. It is provided in the front portion, and the grass presence / absence detecting means is provided at an upper portion of the grass height limiting means and at a position rearward of the front end portion thereof.

A second characteristic configuration is that the grass presence / absence detection means is provided with a movement operation means for moving the grass presence / absence detection sensor along the lateral width direction of the machine body. .

[0010]

According to the first characteristic construction of the present invention, when the grass on the front side of the vehicle body reaches the front end portion of the grass height limiting means provided on the front portion of the vehicle body, it is guided downward and protrudes upward. The grass presence / absence detection sensor, which constitutes the grass presence / absence detection means provided on the upper side of the grass height limiting means and on the rear side of the front end portion thereof, does not directly contact the grass and Therefore, the boundary can be properly detected without being erroneously detected by the presence / absence of grass, for example, cut grass attached to the detection surface.

According to the second characteristic construction, the moving operation means for moving the grass presence / absence detection sensor along the lateral direction of the body directly contacts the grass like the grass presence / absence detection sensor. Since there is no such thing and it is located away from the grass, it avoids the problem that the operation operation becomes abnormal due to the heavy load when moving due to entanglement of cutting grass etc. to the operating mechanism. Thus, the boundary can be properly detected, and damage to the operating mechanism or the like when the load is excessive can be prevented.

[0012]

As described above, according to the first characteristic configuration of the present invention, the erroneous detection of the presence / absence of grass due to the attachment of cut grass or the like can be effectively prevented and the accuracy of boundary detection can be ensured. Based on this, the steering control of the mower can be properly executed.

Further, according to the second characteristic configuration, malfunction and damage of the moving operation means for detecting the presence or absence of grass due to entanglement of cut grass or the like can be effectively avoided, thereby improving the device reliability. The effect of the first characteristic configuration can be further enhanced.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a lawnmower working vehicle as a mower will be described below with reference to the drawings.

As shown in FIGS. 4 to 6, a rotary blade 2 for lawn mowing is attached to the lower portion of a vehicle body V on which an engine E is mounted, and front steering wheels 1F for steering are attached to the front and rear portions of the vehicle body V.
And a pair of left and right drive rear wheels 1L and 1R to which the driving force of the engine E is transmitted via the drive case 3 are attached to form a lawnmower work vehicle. The front wheel 1F is provided with a steering mechanism including a steering gear 1A that directly steers the front wheel, a steering motor M1 for automatic steering, and a motor gear 1B that transmits the driving force of the steering motor M1 to the steering gear 1A. It is attached to the vehicle body V, and
An encoder 14 that detects the number of rotations of the front wheel 1F is provided on the rotation shaft portion of the front wheel 1F. In addition, a fluxgate type geomagnetic sensor S0 using a toroidal core is installed in the vehicle body V in order to detect the current azimuth of the work vehicle during traveling.

At the lower front portion of the vehicle body V, there is provided a guard plate 11 that covers the lower portion on the front side of the vehicle body other than the portion where the front wheels 1F are located, with its lower surface extending along the horizontal direction. The tip of the grass that extends upward is the vehicle body V
As the vehicle travels, it is pushed in the traveling direction and enters the lower side of the guard plate 11. Therefore, the guard plate 11 constitutes a grass height limiting means for guiding the grass, that is, the grass downward, and limiting the upward projection of the grass, that is, the grass. The guard plate 11
As shown in FIG. 2, a pair of left and right cylindrical bodies 12 are oscillated around a vertical axis center by a bearing portion 13 fixed to the vehicle body V at a position on the upper side of the vehicle and on the rear side of the front end portion thereof. It is provided so as not to fall. Then, on the lower front surface side of each of the pair of left and right cylindrical bodies 12, two grass height detection sensors formed of a pair of reflective photointerrupters set so that their detection directions form a predetermined angle (for example, 15 degrees). S1, S2 or S3, S4 are arranged in a distributed manner, and a total of four grass height detection sensors S are provided.
1, S2, S3, and S4 change their detection positions along the lateral width direction of the vehicle body V as the pair of left and right cylindrical bodies 12 are rocked by a rocking mechanism 23 described later.
The presence of uncut grass is detected by emitting an optical signal for detection to the front side of the vehicle body and detecting the reflected light. That is, if there is reflected light, the turf-presence state is detected, while if there is no reflected light, the turf-plucked state is detected. Therefore,
The grass height detection sensors S1, S2, S3, S4 constitute a grass presence detection sensor for projecting a signal for detecting the presence of grass, that is, grass on the grass on the front side of the vehicle body to detect the presence of grass.

The swing mechanism 23 includes an arm 24 projecting inward from the upper side surface of one side (right side) of the pair of left and right cylindrical bodies 12, and a vertical axis core at the tip of the arm 24. It is composed of an eccentric cam 25 arranged so as to come into contact with a rotating wheel 24A pivotally supported around it, and a sensor swinging motor m provided on the upper part for rotating the eccentric cam 25. The arm 24 is urged by a spring material (not shown) or the like in a direction of contacting the eccentric cam 25. Arms 26 are provided so as to project from the upper side surfaces of the pair of left and right cylindrical bodies 12 toward the front side of the vehicle body, and the tip ends of these left and right arms 26 are linked by link bars 28 whose both ends are pivotally supported. It is connected. With the above configuration, when the eccentric cam 25 is rotated by the sensor swinging motor m, the right cylindrical body 12 swings in the vehicle width direction, and in conjunction with this, the left cylindrical body 12 is swung.
Also swings in the vehicle width direction, and a pair of left and right lawn height detection sensors S
1, S2 or the respective grass presence / absence detection positions of the grass height detection sensors S3, S4 are reciprocatingly scanned in the vehicle width direction. Therefore, the rocking mechanism 23 constitutes a movement operation means for moving the grass presence / absence detection sensor, that is, the grass height detection sensors S1, S2, S3, S4 along the lateral direction of the vehicle body.

As shown in FIG. 2, the lawn presence / absence detection position is configured to detect the presence / absence of lawn within a predetermined width W in the vehicle width direction near the tip of the guard plate 11. . That is, the turf height detection sensors S1 and S2 or the turf height detection sensor S that are moved and scanned by the swing mechanism 23.
The presence of grass at a predetermined height above the lower surface of the guard plate 11 is detected by the sensors S3 and S4 at a detection interval obtained by dividing the width W into eight parts. Eight lawn presence / absence data D0 to D7 or D8 to by swing scanning of S1, S2 or S3, S4
D15 is obtained. The data D0 to D15 are digital data indicating "1" when there is grass and "0" when there is no grass. The detection interval is determined by detecting the swing angle of the right cylindrical body 12 with a potentiometer G provided on the rotating shaft of the eccentric cam 25. From the above, the grass presence detection sensor, that is, the grass height detection sensors S1 and S
2, S3, S4 and the swinging mechanism 23 constitute a grass presence / absence detection means 22 for detecting the presence or absence of grass, that is, grass at predetermined intervals along the lateral direction of the vehicle body.

As shown in FIG. 7 and FIG. 8, the driving rear wheels 1L, 1R located on the turning center side at the time of turning are floated on the inside of the pair of left and right driving rear wheels 1L, 1R. It is capable of moving up and down between a descending state in which it descends and an ascending state in which the rear drive wheels 1L and 1R located on the side of the center of turning after the turn is completed are grounded, and the center of turning is formed in the state of lowering. A pair of left and right lifting grounding bodies 9 are attached to the vehicle body V through a grounding mechanism, and
The grounding portion 9A of the lifting / lowering grounding body 9 that grounds to the ground is supported by the base end side of the lifting / lowering grounding body 9 in a rotatable state about the vertical axis. In the grounding mechanism, the bent portions of a pair of left and right doglegged links 4 are swingably attached to the drive case 3 around respective fulcrums P1 and P2, and a lifting grounding body 9 is attached to one end of the link 4. A spring 5 for urging the elevating grounding body 9 upward is attached to the other end, and the other end of the link 4 is grounded to the elevating grounding body 9 against the urging force of the spring 5. It is composed of a cam mechanism 6 for rocking operation. The cam mechanism 6 includes a cam 6A,
A set of gears 7 for rotating the cam 6A, and this gear 7
And a grounding motor 8 connected to the cam 6
Every time A rotates 90 °, a pair of left and right lifting grounding bodies 9
Each of the left and right driving rear wheels 1L and 1R on the side of the elevating and lowering grounding body 9 descends so as to levitate, and rises so as to ground the levitated driving rear wheels 1L and 1R. The states and are alternately repeated.

As shown in FIG. 1, a control device H utilizing a microcomputer is provided, and the control device H includes the geomagnetic sensor S0 and the lawn height detection sensors S1, S2.
Signals from S3, S4, the potentiometer G, and the encoder 14 are input. Further, the control device H outputs drive signals to the steering motor M1, the sensor swinging motor m, and the grounding motor 8. Further, the control device H is connected to a memory MEM for storing information.

The memory MEM and the geomagnetic sensor S
Using 0, the direction of the first work stroke K1 in which the vehicle body V is turned by the worker at the start of work, that is, the direction indicated by the boundary L between the unprocessed work site A and the processed work site B (see FIG. 3). By storing in the memory MEM the angle θ formed by the direction J of the geomagnetism detected by the geomagnetic sensor S0 as the reference azimuth θ ₀ , the direction indicated by the boundary L between the unprocessed work site A and the processed work site B is determined. Reference azimuth setting means 10 for setting the reference azimuth is configured.

Boundary discriminating means 10 for discriminating the boundary L between the unprocessed work site A and the processed work site B based on the detection information of the grass presence / absence detection means 22 using the control device H.
0 is configured. The boundary discrimination operation will be described by taking the state of FIG. 2 as an example. In the eight lawn presence / absence data D0 to D7 obtained as described above, the unprocessed work site A closest to the processed work site B is displayed. The bit position (D3) of the data "1" and the processed work site B closest to the unprocessed work site A side
An intermediate position with respect to the bit position (D2) of the data "0" is determined as the position of the boundary L.

Next, the steering control of the control unit H based on the obtained position information of the boundary L will be described.
The pair of turf height detection sensors S1, S2 or S3, S4 which are determined as proper steering positions in the lateral direction of the vehicle body.
Center position, that is, eight grass presence data D0 to D7
Bit D3 (or D8 of D8 to D15)
11) and the intermediate position between the bit D4 (or D12),
Since the deviation amount deviated from the determined position of the boundary L becomes the position deviation X of the steering position, this position deviation X
The steering motor M1 is controlled so as to be zero so that the proper steering position travels along the boundary L. That is, when the vehicle body V is deviated to the unprocessed work site A side, the vehicle body V is corrected and steered to the processed work site B side (left side in the traveling direction in FIG. 3), and the vehicle body V is processed.
When the vehicle body V is deviated to the side, the vehicle body V is corrected and steered to the untreated work site A side (the right side in the traveling direction in FIG. 3).

Next, the control operation of the control device H will be described with reference to the flow chart shown in FIG.

First, when the control is started,
Is the reference direction θ ₀Initialize and write
Remember, the steering direction of the front wheel 1F is based on this
Sub azimuth θ₀To match. Once you start running
The grass presence data D0 to D15 are sampled and updated at each separation.
To be new. Then, the boundary L of this grass presence data is
Based on the data D0 to D7 on the installed side, as described above
To detect the position of the boundary L and set the proper steering position of the vehicle body V.
The position deviation X with respect to it is detected.

Next, the azimuth deviation Δθ = θ−θ ₀ is calculated from the difference between the current detected azimuth θ and the reference azimuth θ ₀ . And
The position deviation X and the azimuth deviation Δθ are respectively multiplied by predetermined gain coefficients p and q to obtain a steering angle θ _ST by the following formula, and the steering operation is performed at the steering angle θ _ST .

[0027]

[Equation 1] θ _ST = p · X + q · Δθ

Then, the flow from the update of the lawn presence data D0 to D15 for each constant distance running to the steering operation at the steering angle θ _ST is repeated until the vehicle body V detects the headland. Incidentally, the detection of the headland is judged, for example, when all the grass presence data D0 to D15 are in the state of detecting the grass absence data "0".

When it is detected that the headland has been reached, it is further judged whether or not the stroke that has been traveled so far is the final stroke, and if it is the final stroke, the work is ended there, while the final stroke is made. Otherwise, drive rear wheel 1L, as described above,
The elevating grounding body 9 on one side of 1R is used as a turning center, and further, while steering is operated in the turning direction, the drive rear wheels 1L and 1R on the side other than the turning center are driven to move the vehicle body V to the unprocessed work site B side. The vehicle is turned, and the flow from the update of the lawn presence data D0 to D15 for each fixed distance traveling to the steering operation at the steering angle θ _ST is repeated until the vehicle body V detects the headland. During the turning operation, the direction of the vehicle body V is confirmed by the geomagnetic sensor S0.
Information on whether or not it has turned 80 °, and the encoder 14
Drive rear wheel 1L on the side other than the center of turning detected by
It is determined from the traveling amount of 1R that the vehicle is ready for the next work stroke.

[Embodiment] In the above embodiment, the grass presence detection sensors S1, S2, S3 and S4 for projecting a grass presence detection signal onto the grass on the front side of the vehicle body to detect the presence of the grass are used as reflection type photo interrupters. That is, although it is configured as an optical type, it may be configured by an ultrasonic sensor or the like that projects a signal other than light, for example, an ultrasonic signal to the front side and detects the reflected wave.

In the above embodiment, the grass presence / absence detecting means 22 for detecting the presence / absence of grass at predetermined intervals along the lateral direction of the vehicle body.
The presence / absence detection sensors S1, S2, S
Although S3 and S4 are configured to be moved along the width direction of the vehicle body, instead of moving them, a predetermined number of grass presence / absence detection sensors may be arranged along the width direction of the vehicle body.

Further, in the above embodiment, the lawn presence detecting means 22
The moving operation means 23 provided in the above is configured by a swing mechanism that swings the support body of the grass presence / absence detection sensors S1, S2, S3, S4, that is, the cylindrical body 12 about the vertical axis, but not the swing mechanism. For example, the support for the grass presence / absence detection sensors S1, S2, S3, S4 may be linearly moved along the lateral direction of the vehicle body.

Further, in the above embodiment, the grass height limiting means 11 for guiding the grass downward so as to limit the upward projection of the grass,
Although the guard plate is arranged so as to press down the grass on the lower surface thereof, it is not always necessary to form it into a plate shape, and for example, a mesh body in which a fine mesh is formed so as not to pass grass may be used.

Further, in the above-mentioned embodiment, the present invention is applied to the lawnmower work vehicle, but it can be applied to various mowers other than this.

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

[0036]

[Brief description of drawings]

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

FIG. 2 is a plan view of a grass presence detection unit.

FIG. 3 is an explanatory diagram of a work form

FIG. 4 is a schematic plan view of a vehicle body.

FIG. 5 is a schematic side view of a vehicle body.

FIG. 6 is a schematic front view of a vehicle body.

FIG. 7 is a rear view of the turning mechanism.

FIG. 8 is an operation explanatory view of the turning mechanism.

FIG. 9 is a flowchart of control operation.

[Explanation of symbols]

 S1, S2, S3, S4 Grass presence / absence detection sensor 22 Lawn presence / absence detection means A Unprocessed work area B Treated work area L Boundary 100 Boundary discrimination means 11 Grass height limiting means 23 Moving operation means

Claims (2)

[Claims] 1. A grass presence / absence detection sensor (S) for detecting the presence / absence of a grass presence / absence detection signal by projecting it onto the grass in front of the vehicle body.
1, S2, S3, S4) to detect the presence or absence of grass at predetermined intervals along the lateral direction of the vehicle body (2)
2) and a boundary discriminating means (100) for discriminating the boundary (L) between the unprocessed work site (A) and the processed work site (B) based on the information of the grass presence / absence detection means (22). And a grass height limiting means (11) for guiding the grass downward to limit upward projection of the grass, the grass presence / absence detecting means being provided. (22) is a boundary detection device for a mower, which is provided above the grass height limiting means (11) and at a position rearward of its front end. 2. The boundary detection device for a mower according to claim 1, wherein the grass presence / absence detection means (22) includes the grass presence / absence detection sensors (S1, S2, S3, S4) in a lateral direction of the machine body. A boundary detecting device for a mower, which is configured to include a moving operation means (23) for moving and moving.