JP2731679B2 - Mower boundary detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grass presence / absence detection sensor for projecting a grass presence / absence detection signal to grass on the front side of a vehicle body to detect the presence or absence of the grass at predetermined intervals along the vehicle width direction. The present invention relates to a boundary detection device for a mowing machine, comprising: a grass presence detection unit that detects presence / absence; and a boundary determination unit that determines a boundary between an unprocessed work place and a processed work place based on information of the grass presence detection means. .

[0002]

2. Description of the Related Art A boundary detecting device for a mower of this type is used, for example, in a self-propelled lawn mowing vehicle for cutting grass as grass without manual intervention. For example, a grass presence / absence detection sensor composed of a reflection type photo interrupter projects the grass on the front side of the vehicle body while changing the projection direction of the optical signal for grass presence detection along the vehicle width direction, and reflects the reflected light. The presence of grass detected the grassy state while the absence of reflected light detected the grassless state. Then, based on the detection result of the grass presence state at predetermined intervals along the vehicle body width direction, for example, a grassed position located closest to the processed work place in the unprocessed work place and a most unprocessed work in the processed work place are obtained. An intermediate position between the grassless position located on the ground side and the unprocessed work land and the processed work land is determined.

Conventionally, however, the grass presence / absence detection sensor is configured to detect the presence or absence of grass in a state where the grass enters 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. In this case, the grass presence / absence detection signal is always on, that is, there is grass. Or it is always off, that is, without grass. In the former case, it is erroneously detected that the front side of the vehicle body is an unprocessed work site, that is, the boundary is not located on the front side of the vehicle body but is located on the processed work side side. As a result, if the steering control is performed based on this boundary detection information, the mowing work cannot be performed because the position is unnecessarily shifted to the processed work site side, whereas in the latter case, the entire front side of the vehicle body is processed. As a result of being erroneously detected as being a work place, that is, the boundary is not located on the front side of the vehicle body and is located off the unprocessed work side, steering control is performed based on this boundary detection information. In such a case, the position is unnecessarily shifted to the unprocessed work site side, so that uncut leaves are generated. Eventually, in both cases, the vehicle body may jump out of the work place and come into contact with other objects, possibly damaging the vehicle body or the like.

In a case where the detection position of the grass presence detection sensor at predetermined intervals along the vehicle width direction is changed by a mechanical moving mechanism operated by a driving force from a motor or the like, Not only does the sensor move improperly due to an increase in the operating load of the mechanical moving mechanism due to the attachment of cut grass and the like, but also when the load is excessive, the mechanical mechanism or the motor may be damaged. Was.

Therefore, in order to avoid these problems, if the grass presence / absence detection signal is always 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. Automatic driving is started again from. However, in this case, the work is interrupted every time the sensor is detected abnormally, so that another problem that the work efficiency is reduced occurs.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to prevent the occurrence of erroneous detection of the presence or absence of grass due to the attachment of cut grass or the like and to ensure the accuracy of boundary detection. It is another object of the present invention to provide a boundary detection device for a mowing machine in which a malfunction or damage of a moving operation means for detecting the presence or absence of grass due to entanglement of cut grass or the like is avoided.

[0008]

A first feature of the boundary detecting device for a mower according to the present invention is that a grass height limiting means for guiding grass downward and restricting the grass from projecting upward is provided on the body. It is provided in the front part, and the above-mentioned grass presence detection means is provided in the upper part of the above-mentioned grass height restriction means, and in the back side position from the front end.

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 of the body. .

[0010]

According to the first feature of the present invention, when the grass on the front side of the vehicle reaches the front end of the grass height limiting means provided at the front of the vehicle, the grass is guided downward and protrudes upward. The grass presence detection sensor which constitutes the grass presence detection means provided above the grass height limitation means and at a position behind the front end thereof does not directly contact the grass, and Therefore, the boundary detection can be properly performed without, for example, cutting grass or the like adhering to the detection surface and erroneously detecting the presence or absence of the grass.

According to the second characteristic configuration, the moving operation means for moving the grass presence / absence detection sensor along the width direction of the body directly contacts the grass similarly to the grass presence / absence detection sensor. It is located at a distance from the grass, and it is possible to avoid the problem that the movement load becomes large due to the entanglement of cut grass etc. on the operation mechanism and the movement operation becomes abnormal. As a result, the boundary detection can be performed properly, and damage to, for example, the operation mechanism or the like under an excessive load can be prevented.

[0012]

Therefore, according to the first characteristic configuration of the present invention, erroneous detection of the presence or absence of grass due to the attachment of cut grass or the like is effectively prevented, and the accuracy of boundary detection is ensured. , 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 and the like are effectively avoided, and the reliability of the apparatus is improved. 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 lawn mower as a mower will be described below with reference to the drawings.

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

A guard plate 11 is provided at a lower front portion of the vehicle body V so as to cover a lower portion on the front side of the vehicle body other than a portion where the front wheel 1F is located, with its lower surface extending along the horizontal direction. The tip of the turf extending 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 grass height limiting means for guiding the grass, that is, the grass, to the lower side 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 swingable about a vertical axis by a bearing portion 13 fixed to the vehicle body V at an upper portion of the vehicle and at a position behind the front end thereof. It is provided in a state where it is supported so as not to fall. Two grass height detection sensors each comprising a pair of reflective photointerrupters whose detection directions are set to form a predetermined angle (for example, 15 degrees) on the lower front side of each of the pair of left and right cylindrical bodies 12. S1, S2 or S3, S4 are distributed, and a total of four turf height detection sensors S
1, S2, S3, and S4 change their detection positions along the lateral width direction of the vehicle body V as the pair of right and left cylinders 12 are rocked by the rocking mechanism 23 described later.
The presence or absence 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 presence of turf is detected, while if there is no reflected light, the absence of turf in which the turf is cut is detected. Therefore,
The grass height detection sensors S1, S2, S3, and S4 constitute a grass presence detection sensor that projects a signal for grass presence detection, that is, grass presence detection grass, on the front side of the vehicle body.

The swing mechanism 23 includes an arm 24 projecting inward from the upper side of one (right) side of the pair of left and right cylindrical bodies 12 and a longitudinal axis centered at a tip end of the arm 24. The eccentric cam 25 is arranged so as to be in contact with the rolling wheel 24A pivotally supported therearound, and a sensor swing motor m provided at an upper portion thereof for rotating the eccentric cam 25 is provided. The arm 24 is urged by a spring material (not shown) in a direction in which the arm 24 comes into contact with the eccentric cam 25. Further, an arm 26 is provided so as to protrude forward from the upper side surface of each of the pair of left and right cylindrical bodies 12 toward the front of the vehicle body, and tips of the left and right arms 26 are linked by link rods 28 pivotally supported at both ends thereof. Are linked. With the above configuration, when the eccentric cam 25 is rotated by the sensor swing motor m, the right cylindrical body 12 swings in the vehicle width direction, and in conjunction with this, the left cylindrical body 12
Also swings in the vehicle width direction, and a pair of right and left turf height detection sensors S
The turf presence / absence detection positions of the turf height detection sensors S3 and S4 are reciprocally scanned in the vehicle width direction. Therefore, the rocking mechanism 23 constitutes a moving operation means for moving the grass presence / absence detection sensor, that is, the grass height detection sensors S1, S2, S3, S4, in the vehicle width direction.

As shown in FIG. 2, the turf presence / absence detection position is configured to detect the presence / absence of turf within a predetermined width W along 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 sensors S that are moved and scanned by the swing mechanism 23 are scanned.
3 and S4, the presence or absence of a turf at a position above the lower surface of the guard plate 11 by a predetermined height is detected at detection intervals obtained by dividing the width W into eight, whereby a pair of turf height detection sensors is provided. Eight turf presence / absence data D0-D7 or D8- by swing scanning of S1, S2 or S3, S4
D15 is obtained. Each of the data D0 to D15 is 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 rotation shaft of the eccentric cam 25. As described above, the grass presence / absence detection sensors, that is, the grass height detection sensors S1, S
2, S3, S4 and the rocking mechanism 23 constitute grass presence / absence detection means 22 for detecting the presence / absence of grass, that is, grass at predetermined intervals along the vehicle body width direction.

As shown in FIGS. 7 and 8, inside the pair of left and right driving rear wheels 1L and 1R, the driving rear wheels 1L and 1R located on the turning center side during turning are lifted from the ground. It can move up and down between a descending state in which it descends and an ascending state in which the driven rear wheels 1L, 1R located on the turning center side after turning is completed so as to contact the ground, and form the turning center in the descending state. A pair of left and right lifting type grounding bodies 9 are attached to the vehicle body V via a grounding mechanism.
The grounding portion 9A of the liftable grounding body 9 grounded on the ground is supported by the base end side of the liftable grounding body 9 so as to be rotatable around a vertical axis. The grounding mechanism attaches the bent portions of the pair of left and right U-shaped links 4 to the drive case 3 so as to be swingable around respective fulcrums P1 and P2, and attaches a vertically movable grounding body 9 to one end of the link 4. A spring 5 for urging the liftable grounding body 9 upward is attached to the other end, and the other end of the link 4 is grounded against the urging force of the spring 5. And a cam mechanism 6 for swinging operation. The cam mechanism 6 includes a cam 6A,
A set of gears 7 for rotating the cam 6A;
And a grounding motor 8 connected to the
Each time A rotates 90 °, a pair of left and right lifting type grounding bodies 9
Are respectively lowered so as to float the pair of left and right driving rear wheels 1L and 1R on the side of the lifting type grounding body 9, and ascending so as to ground the floating driving rear wheels 1L and 1R. The state is alternately repeated.

As shown in FIG. 1, a control device H using a microcomputer is provided. The control device H includes the geomagnetic sensor S0, the turf height detection sensors S1, S2,
Signals from S3 and S4, the potentiometer G, and the encoder 14 are input. In addition, a drive signal is output from the control device H to the steering motor M1, the sensor swing motor m, and the grounding motor 8. The control device H is connected to a memory MEM for storing information.

The memory MEM and the geomagnetic sensor S
0, the direction of the first work step K1 in which the worker turns the vehicle body V at the start of the work, that is, the direction indicated by the boundary L between the unprocessed work place A and the processed work place B (see FIG. 3). and by storing in the memory MEM as a reference azimuth theta ₀ the angle theta between the geomagnetic direction J of the geomagnetic sensor S0 detects the direction indicated by the boundary L of the processed work locations B and untreated work areas a Reference azimuth setting means 10 for setting as the reference azimuth is configured.

The controller H is used to determine a boundary L between the unprocessed work site A and the processed work site B based on the detection information of the grass presence detector 22.
0 is configured. The boundary discriminating operation will be described with reference to the state of FIG. 2 as an example. In the eight turf presence / absence data D0 to D7 obtained as described above, the unprocessed work site A closest to the processed work site B side is determined. Bit position (D3) of data "1" and processed work place B closest to unprocessed work place A side
Is determined as the position of the boundary L with respect to the bit position (D2) of the data “0”.

Next, the steering control of the control device 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 determined as appropriate steering positions in the vehicle width direction.
, Ie, eight turf presence / absence data D0 to D7
(Or D8 to D15) of bit D3 (or D3)
11) and the intermediate position between bit D4 (or D12) is
The deviation amount deviated from the position of the determined boundary L is the position deviation X of the steering position.
The steering control is performed such that the steering wheel M1 is controlled to zero so that the proper steering position travels along the boundary L. That is, when the vehicle body V is shifted to the unprocessed work place A side, the vehicle body V is corrected and steered to the processed work place B side (the left side in the traveling direction in FIG.
If it is shifted to the side, the vehicle body V is corrected and steered to the unprocessed 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 flowchart shown in FIG.

First, when the control is started, at the start of traveling,
Is the reference azimuth θ. ₀Initially set to
And remember the steering direction of the front wheels 1F
Quasi-azimuth θ₀Adjust to When you start running, a certain mileage
The grass presence data D0 to D15 are sampled every
To renew. The boundary L in the turf presence data is
Based on the data D0 to D7 on the
To detect the position of the boundary L, and set the vehicle body V to the proper steering position.
Then, the position deviation X 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 equation, 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 updating of the turf presence / absence data D0 to D15 for each traveling of the fixed distance to the steering operation at the steering angle θ _ST is repeated until the vehicle body V detects the headland. The detection of the headland is determined, for example, when all of the turf presence / absence data D0 to D15 is in a state of detecting turf absence data “0”.

If it is detected that the vehicle has reached the headland, it is further determined whether or not the traveled route is the final travel. If the travel is the final travel, the work is terminated. If not, as described above, the driving rear wheel 1L,
The vehicle body V is moved to the unprocessed work place B side by driving the drive rear wheels 1L and 1R on the side not on the turning center while operating the steering in the turning direction with the lifting type grounding body 9 on one side of the 1R as the turning center. After turning, the flow from the update of the turf presence / absence data D0 to D15 for every fixed distance travel to the steering operation at the steering angle θ _ST is repeated until the vehicle body V detects the headland. At the time of the turning operation, the direction of the vehicle body V is confirmed by the geomagnetic sensor S0, and 1
Information on whether the vehicle has turned 80 ° and the encoder 14
, The driving rear wheel 1L on the side other than the turning center,
It is determined from the travel distance of 1R that the vehicle has moved to the next work process.

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

In the above embodiment, the grass presence detecting means 22 for detecting the presence or absence of grass at predetermined intervals along the width direction of the vehicle body.
The grass presence detection sensors S1, S2, S
3, S4 is configured to move along the vehicle width direction. However, instead of moving, for example, a predetermined number of grass presence / absence detection sensors may be arranged along the vehicle width direction.

In the above embodiment, the turf presence detecting means 22
The moving operation means 23 provided in the above is constituted by a swinging mechanism that swings the support of the grass existence detection sensors S1, S2, S3, and S4, that is, the cylindrical body 12 around the vertical axis, but is not a swinging mechanism. For example, a configuration may be employed in which the support of the grass presence detection sensors S1, S2, S3, and S4 is linearly moved along the vehicle width direction.

In the above embodiment, the grass height limiting means 11 for guiding the grass downward and restricting the grass from projecting upward is provided.
Although the guard plate is arranged so as to press the grass on the lower surface thereof, the guard plate is not necessarily required to be formed in a plate shape. For example, a net-like body having a fine mesh so as not to pass through the grass may be used.

In the above-described embodiment, the present invention is applied to a lawn mower. However, the present invention can be applied to various other mowers.

Incidentally, reference numerals are written in the claims for convenience of comparison with the drawings, but the present invention is not limited to the configuration of the attached drawings by the entry.

[0036]

[Brief description of the drawings]

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

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

FIG. 3 is an explanatory diagram of a work mode.

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 explanatory diagram of the operation of the turning mechanism.

FIG. 9 is a flowchart of a control operation.

[Explanation of symbols]

 S1, S2, S3, S4 Grass presence / absence detection sensor 22 Turf presence / absence detection means A Unprocessed work area B Processed work area L Boundary 100 Boundary determination means 11 Grass height restriction means 23 Movement operation means

Claims (2)

(57) [Claims] 1. A grass presence detection sensor (S) for projecting a grass presence detection signal onto grass on the front side of a vehicle body to detect the presence thereof.
1, S2, S3, S4), grass presence detecting means (2) for detecting the presence or absence of grass at predetermined intervals along the vehicle body width direction.
2) and a boundary determining means (100) for determining a boundary (L) between the unprocessed work place (A) and the processed work place (B) based on the information of the grass presence detecting means (22). A grass height limiting means (11) for guiding the grass downward and restricting the grass from projecting upward, provided at the front of the fuselage; (22) A mowing machine boundary detecting device provided above the grass height limiting means (11) and at a position behind the front end thereof. 2. The boundary detecting device for a mowing machine according to claim 1, wherein said grass presence detecting means (22) controls said grass presence detecting sensor (S1, S2, S3, S4) along a machine body width direction. A boundary detecting device for a mowing machine, comprising a moving operation means (23) for performing a moving operation.