JPH064128A - Border detecting device for lawn mowing machine - Google Patents

Abstract

PURPOSE:To stably detect the border between unmown and a mown place without being affected by disturbance by correcting lawn presence information into lawn absence information unless other lawn presence information is present nearby the position of the lawn presence information in currently sampled lawn presence/absence information. CONSTITUTION:A border deciding means 100 decides the border between the unmown place and mown place by sampling pieces of information of means 22 and 23 which detect whether or not there is the lawn at specific intervals in the breadth direction of a machine body. The border deciding means 100 corrects the lawn presence information into the lawn absence information unless there is other lawn presence information nearby the lawn presence information in the currently sampled lawn presence/absence information. Further, the border deciding means 100 ORs the lawn presence information with the current corrected detection information and last and several precedent pieces of lawn absence information. Then the border deciding means 100 decides the border according to the information obtained by the OR operation. Consequently. the influence of the disturbance is precluded.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to lawn presence / absence detecting means for detecting the presence or absence of lawn at predetermined intervals along the lateral direction of a vehicle body, and the information of the lawn presence / absence detecting means for sampling unprocessed work sites and processing. The present invention relates to a boundary detection device for a lawnmower work vehicle, which is provided with a boundary determination means for determining a boundary with a completed work site.

[0002]

2. Description of the Related Art This type of boundary detection device for lawnmower work vehicles is used, for example, in a self-propelled work vehicle for performing lawn mowing work without manpower. Lawn presence / absence data (for example, 8 pieces) is sampled at predetermined intervals along the lateral direction of the vehicle body for each traveling distance, and is located on the most processed work site side (that is, the cut side) of the sampled lawn presence / absence data. The midpoint between the position of the data with grass on the unprocessed work site side (that is, the uncut side) and the position of the data without grass on the adjacent processed work site side is used as the boundary between the unprocessed work site and the processed work site. Had been determined. The working vehicle is steering-controlled based on the boundary information so that the vehicle body is maintained at the proper steering position.

[0003]

By the way, normally, on the side of the processed work site where the mowing work has already been completed, originally the data with grass should not be detected, but for example, mowed grass and dust, etc. When there is, the data with grass may be detected by being surrounded by the data without grass. At this time, in the above-mentioned conventional means, it is determined that the boundary suddenly enters the processed work site side. Further, generally, the turf planting state of the lawn mowing work site is not uniform over the entire surface thereof, and the sparse and dense state is usually changed depending on the place. In this case, in the above-mentioned conventional means, for example, even in the case of straight line cutting and mowing, the processed work site enters the unprocessed work site side near the sparse condition due to the influence of the sparse grass, It is determined that the boundary is curved to the unprocessed work side. Therefore, when the steering control is performed based on the boundary detection information by the above-mentioned conventional means, it is arranged so as to follow the position of the boundary suddenly entering the processed work site side or the position of the boundary curved to the unprocessed work site side. As a result of the steering control, although the original boundary between the two work sites is, for example, a straight line, hunting due to unnecessary steering operation etc. occurs and the traveling becomes unstable, and the time required for the work is long. Therefore, there was a problem that the work efficiency was lowered.

The present invention has been made in view of the above circumstances, and its object is to avoid being affected by disturbance such as the presence of foreign matter such as mowed grass and dust or the density of turf planting. An object of the present invention is to obtain a boundary detection device capable of stably detecting a boundary between an unprocessed work site and a processed work site.

[0005]

According to a first characteristic configuration of a boundary detection device for a lawnmower work vehicle according to the present invention, the boundary determination means includes the presence / absence information of the grass sampled at the predetermined intervals and the previously sampled data. In the turf presence / absence information array in which the turf presence / absence information for each predetermined interval is aligned with the position for each predetermined interval in the lateral direction of the vehicle body, another turf presence information in the turf presence / absence information in the turf presence / absence information sampled at this time When there is no grass information, the grass information is corrected to the no grass information.

A second characteristic configuration is that the boundary determining means has the grass presence / absence information sampled this time and subjected to the correction processing, and one or more grasses sampled before this time and subjected to the correction processing a plurality of times. It is configured such that a logical sum operation is performed on the grass presence information with respect to the detection information of the presence / absence information at each of the predetermined intervals, and the boundary is determined based on the information obtained by the logical sum operation.

[0007]

According to the first characteristic configuration of the present invention, the two-dimensional array (that is, the array of the turf presence information sampled this time and the previous time sampled) is arranged at the predetermined intervals along the lateral direction of the vehicle body. This corresponds to a state in which the work target is viewed in plan), and when the grass-existing data is isolated in the area surrounded by the grass-excluding data, the grass-excluding data is replaced with the grass-excluding data. To be done. In other words, even if the grass is erroneously detected as turf in the processed work area due to, for example, mowed grass or dust, the turf presence information is corrected so that the erroneous data is removed. The boundary is determined based on

According to the second characteristic configuration, the grass presence / absence information sampled this time, that is, the grass presence / absence data at predetermined intervals along the lateral direction of the vehicle body, and the grass presence / absence data sampled one or more times before this time. After the removal processing is performed on the grass-existing data isolated in the area of the grass-existing data, a logical sum operation is performed on the grass-existing data at the same data position in the lateral direction of the vehicle body. That is, if there is at least one turf existence data in the sampling data of any one of the above-described times at a certain data position in the vehicle body lateral direction, the result of the logical sum operation at that data position is the turf existence data. In other words, the processed work area (area of turf-free data) that had partially entered the unprocessed work area (area of turf-containing data) was modified to move to the processed work area side. The boundary is determined based on the grass presence information.

[0009]

Therefore, according to the first characteristic configuration of the present invention, even if foreign matter such as grass and dust that has already been cut off is present on the untreated work site side, it is not affected by them. In addition, the boundary between the unprocessed work site and the processed work site can be stably detected, and accordingly, the steering control of the lawnmower work vehicle can be stably and favorably performed based on the boundary information.

According to the second characteristic constitution, in addition to the effect of the first characteristic constitution, for example, the boundary between the untreated work site and the treated work site is affected by the density of the turf planting state. Even if it looks like it is partially curved toward the unprocessed work site, it is possible to detect a boundary that naturally changes smoothly, for example, in a straight line or in a curved line. Based on the above, the steering control of the lawnmower work vehicle can be performed more stably and satisfactorily.

[0011]

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

As shown in FIGS. 4 to 5, a rotary blade 2 for lawn mowing is attached to a lower portion of a vehicle body V on which an engine E is mounted, and front steering wheels 1F for steering are attached to 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.

On the rear side of the vehicle body V, there are spiked wheels 16 that rotate by contact with the ground, and a pair of left and right gear mechanisms 17 that transmit the rotational force of the spiked wheels 16.
And a pair of left and right rotating brushes 18 that rotate around a horizontal axis by receiving the rotational driving force transmitted from the pair of left and right gear mechanisms 17, respectively, and further, the pair of left and right rotating brushes 18 respectively. Is arranged in an oblique state in which the inner side position of the rotation axis of the vehicle body is located on the rear side of the vehicle body with respect to the outer side position of the vehicle body. Then, as the vehicle travels, the rotating brush 18
When the blade is rotated, the grass cut by the rotary blade 2 is blown obliquely to the left and right of the vehicle body V, and the rotary blade 2 cuts the grass in the uncut side area, that is, it is determined as described below. The cut grass is prevented from accumulating in the vicinity of the boundary L between the unprocessed work site A and the processed work site B.

As shown in FIG. 2, on the front side of the vehicle body V,
Four grass height detection sensors S1, S2, S3, S4, which are reflection type photointerrupters for detecting the presence or absence of uncut grass
Are distributed through a swing mechanism 23 that swings the vehicle body V in the vehicle width direction, and the turf height detection sensors S1,
S2, S3, and S4 detect a grass-free state in which the grass has not been mowed if the grass height is large, and detect a grass-less condition in which the grass has been mowed if the grass height is small. . Therefore,
The lawn height detection sensors S1, S2, S3, S4 constitute a lawn presence / absence detection sensor 22.

In the swinging mechanism 23, a front end bifurcated arm 24, whose base end is rotatably attached to the front end of the vehicle body V so as to be rotatable around the longitudinal axis, is positioned by a spring 27 in the machine advancing direction. The cam mechanism 25 is arranged such that the eccentric cam 25A abuts the auxiliary arm 24A attached to the base end of the arm 24. The turf height detection sensors S1 and S2 or the turf height detection sensors S3 and S4, which are arranged at a distance W in the vehicle width direction, are attached to the bifurcated distal ends of the arms 24 via mounting members 26. It is installed. The mounting member 26 is formed by the turf height detecting sensors S1, S2 or the turf height detecting sensor S.
In order to adjust the ground height of S3 and S4, the vertical position is adjusted by the vertical adjustment mechanism provided in the middle thereof, and then the tip side portion 26B is fixed (see FIG. 6). With the above configuration, when the eccentric cam 25A is rotated by the sensor swing motor m (see FIG. 1), the arm 24
Swings in the vehicle width direction, and a pair of left and right lawn height detection sensors S
1, S2 or turf height detection sensors S3, S4 are reciprocally scanned in the lateral direction of the vehicle body.

Therefore, the presence or absence of turf at a predetermined ground height is determined by the turf height detection sensors S1 and S2 or the turf height detection sensors S3 and S4 that are oscillated and scanned by the oscillating mechanism 23 to determine the interval. W is detected at four detection intervals (which corresponds to a predetermined interval), whereby eight turf presence / absence data D0 to D7 are obtained by swing scanning of the pair of sensors S1, S2 or S3, S4. Each data D
0 to D7 are digital data indicating "1" when there is grass and "0" when there is no grass. The detection interval is the potentiometer G provided on the rotation shaft of the eccentric cam 25A.
It is determined by detecting the scanning position by. As described above, the presence / absence of turf for detecting presence / absence of turf at predetermined intervals along the lateral direction of the vehicle body by the turf presence / absence detection sensor 22 including the turf height detection sensors S1, S2, S3, S4 and the swing mechanism 23. The detection means 22 and 23 will be comprised.

Further, as shown in FIG.
Is pivotally supported and attached to the arm 24 so as to be swingable back and forth in the traveling direction with its upper base end serving as a fulcrum, and at a midway point thereof, a protruding portion 2 protruding forward of the machine body.
6A is provided, and a spring 28 for urging the attachment member 26 toward the front side of the machine body is provided between the protruding portion 26A and the tip end portion of the arm 24, and an adjustment for adjusting the angle of the attachment member 26 is provided. With the tip of the screw 29 abutting against the arm 24 by the urging force of the spring 28, the protrusion 2
6A is screwed and supported by internal fitting. As a result, the turf height detecting sensors S1, S2 or the turf height detecting sensor S3,
When S4 hits a foreign object, etc., it will fall rearward to avoid damage to the grass height detection sensor as much as possible, and the backward tilt is limited to only the grass height detection sensor hitting a foreign object. The detection operation of the other grass height detection sensors can be continuously performed.

As shown in FIG. 7 and FIG. 8, the driving rear wheels 1L and 1R located on the turning center side at the time of turning are floated on the inside of the left and right driving rear wheels 1L and 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 and a cam 6A.
And a grounding motor 8 connected to the gear 7 and a pair of gears 7 for rotating the
Each time it rotates, the pair of left and right lifting grounding bodies 9 are connected to each other by the pair of left and right driving rear wheels 1 on the side of the lifting grounding body 9.
The descending state in which the L and 1R are lowered so as to levitate and the ascending state in which the levitated rear drive wheels 1L and 1R are raised so as to contact the ground are alternately repeated.

As shown in FIG. 1, a control device H using a microcomputer is provided.
Signals from the lawn height detection sensors S1, S2, S3, S4, the potentiometer G, the geomagnetic sensor S0, and the encoder 14 are input to the. Further, a drive signal is output from the control device H 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 100 for discriminating the boundary L between the unprocessed work site A and the processed work site B by sampling the information of the lawn presence / absence detection means 22 and 23 using the control device H. Is configured. Then, the boundary determining means 100 arranges the turf presence / absence information for each of the predetermined intervals sampled this time and the turf presence / absence information for each of the predetermined intervals sampled last time so as to align the positions of the predetermined intervals in the lateral direction of the vehicle body. In the array of turf presence information, when there is no other turf presence information near the turf presence information in the turf presence information sampled this time, the turf presence information is corrected to turf absence information. , Turf presence information with respect to the detection information at each predetermined interval of the turf presence information sampled this time and subjected to the correction process and the turf presence information sampled before this time and subjected to the correction process one or more times Is performed, and the boundary L is discriminated based on the information obtained by the logical addition.

The boundary discriminating means 100 will be described in detail below. As shown in FIG. 9A, the grass presence information is sampled every time the vehicle travels a certain distance along the work stroke, and eight grass presence data corresponding to the detection information at the predetermined intervals are sampled once. D0 to D7 are obtained. Then, the eight grass presence data D0 to D7
Are repeatedly sampled, sequentially stored, and arranged two-dimensionally. In the example shown in the figure, a region of data “0” determined to have no grass penetrates into a part of the unprocessed worksite A side, and a data “0” determined to have grass is present in the processed worksite B. 1 "points (the ones that have already been mowed, detected dust, etc.) exist in isolation.

Then, in the arrangement of the above data, FIG.
As shown in 0, bits Dn-1, Dn + 1 and the previous data which are adjacent on both sides in the current data and are located so as to surround the bit Dn (indicated by *) in the current data The positions of the bits Dn, Dn-1, and Dn + 1 of 5 bits in total are defined as neighborhood positions, and the noted bit Dn
Even if (indicated by *) is data "1", if all the 5 bits in the vicinity are data "0", the bit D of interest
The n is corrected to the data “0”. The bit D7 located closest to the unprocessed work site A has a bit of data "1" adjacent to the unprocessed work site A side, and conversely the bit D0 located on the most processed work site B side. Processed work site B
The correction process is performed on the assumption that the data “0” bits are adjacent to each other. FIG. 9B shows the result of performing the above correction processing on the data of FIG. 9A. It can be seen that the isolated point of the data "1" in the processed work site B has been erased by the correction.

Next, for each of the bits D0 to D7 of the grass presence / absence data D0 to D7 which have been subjected to the above-mentioned correction processing, for the sampling data of this time and the sampling data of three times before this time, a total of four times of data. The logical sum operation is performed on the grass presence information, that is, the data "1". That is, in each of the bits D0 to D7, if the data is "1" even once even among the above four times of data, the result of the logical sum operation is regarded as the data "1", that is, the presence of grass. The result of this logical sum operation is shown in FIG. 9 (c). It can be seen that the area of the data “0” that has entered a part of the unprocessed work site A side has moved to the processed work site B side. I understand. An intermediate point between the bit position of the data “1” of the unprocessed work site A closest to the processed work site B side and the bit position of the data “0” of the processed work site B closest to the unprocessed work site A side. The position of is determined as the position of the boundary L. Incidentally, FIG. 9D shows the result of performing only the logical sum operation without performing the correction process. In this case, the isolated point of the data “1” is not erased and the influence of the isolated point is exerted. It can be seen that the position of the boundary L is deviated to the processed work site B side and detected.

Further, the control device H is configured to control the steering so that the control device H travels along the boundary L discriminated by the boundary discriminating means 100. That is,
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.
The center position of the detection range, that is, the intermediate position between the bit D3 and the bit D4 is deviated from the position of the boundary L determined as described above. The deviation amount is the position deviation of the steering position. Therefore, the steering motor M1 is controlled so that the positional deviation X becomes zero, and the steering control is performed so that the proper steering position travels along the boundary L. The direction of the deviation is defined so that the position deviation X becomes negative when the vehicle body V is deviated to the unprocessed work site A side. Therefore, if the position deviation X is negative, the vehicle body V is corrected and steered to the processed land B side (left side in the traveling direction in FIG. 3), and if the position deviation X is positive, the vehicle body V is processed side B. Therefore, the vehicle is corrected and steered to the untreated area A side (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.

Firstly, the traveling start, as well as initialization and stores the direction in which the vehicle V is oriented in the reference direction theta _0, adjust the steering direction of the front wheels 1F to this reference direction theta _0. When the running is started, the grass presence / absence data D0 to D7 are sampled at every constant running distance. Then, when the sampling of this data is performed twice, the previous time and the current time, the correction processing in the vicinity is performed. When the data is sampled four times, that is, when data is sampled three times this time and before this time, as described above, the logical sum operation is performed on each bit of the grass presence data D0 to D7 four times. After that, the position of the boundary L is detected, and the position deviation X with respect to the proper steering position of the vehicle body V 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 .

[0030]

[Equation 1] θ _ST = p · X + q · Δθ

Then, among the total 16 grass presence / absence data obtained by one-way scanning the four grass height detection sensors S1, S2, S3, S4 constituting the grass presence / absence detection sensor 22 in the lateral direction of the vehicle body. 1 ”, that is, if the number of data with turf is less than a certain value (for example, 4) and it is detected that the user has traveled to the headland, that is, has reached the end of one work stroke, as described above. In addition, the elevating type grounding body 9 on one side of the drive rear wheels 1L and 1R is used as the turning center, and further, while the steering operation is performed in the turning direction, the drive rear wheels 1 not on the turning center are provided.
The vehicle body V is turned by driving L and 1R.
At this time, the direction of the vehicle body V is confirmed by the geomagnetic sensor S0, and information indicating whether or not the direction is 180 ° with respect to the direction K1 of the first work stroke and the turning center detected by the encoder 14 are not included. It is determined from the traveling amounts of the rear drive wheels 1L and 1R on the side that the vehicle is heading for the next second work stroke.

[Other Embodiments] In the above embodiment, the lawn presence detecting means 22 and 23 for detecting the presence or absence of lawn at predetermined intervals along the lateral direction of the vehicle body are configured to swing in the lateral direction of the machine body. Alternatively, a plurality of sensors may be fixedly provided in the lateral direction of the machine body. Although the number of pieces of data obtained by the lawn presence / absence detecting means 22 and 23 is set to eight, in the case of detecting with higher accuracy, for example, 16 pieces of data can be obtained, or in the case of simplification. The number of data can be appropriately set according to the situation, such as obtaining four data.

In the above embodiment, the boundary discriminating means 100 is used.
Defines the 5 bits as a position near the bit Dn of interest in this data (see FIG. 10),
Instead of these 5 bits, for example, if adjacent to both sides of the bit Dn in this data, 2 bits Dn-1 and Dn + 1 are provided.
The specific configuration of the correction process can be changed as appropriate, for example, by defining the position of a total of 3 bits of the bit Dn in the previous data as a near position and performing the correction process.

In the above embodiment, the boundary discriminating means 100 is used.
Uses the grass presence / absence data D0-D7 sampled three times before this time as the target for performing an OR operation on the grass presence data D0-D7 sampled this time. Instead, the number of times such as twice or four times can be appropriately changed according to the situation of the work site.

In the above embodiment, the present invention is applied to a lawn mowing work vehicle, but it can be applied to other mowing work vehicles and the like.

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.

[0037]

[Brief description of drawings]

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

FIG. 2 is a plan view of the lawn presence detection means.

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 side view of the lawn presence detector.

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

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

FIG. 9 is an explanatory diagram of the operation of the boundary discriminating means.

FIG. 10 is an explanatory diagram of the operation of the boundary discriminating means.

FIG. 11 is a flowchart of control operation.

[Explanation of symbols]

 A unprocessed work site B processed work site L boundary 100 boundary determination means 22, 23 lawn presence detection means

Claims (2)

[Claims] 1. A lawn presence detecting means (22, 23) for detecting the presence or absence of lawn at predetermined intervals along the lateral direction of the vehicle body, and information of the lawn presence detecting means (22, 23) is sampled and unprocessed. A boundary detection device for a lawnmower equipped with a boundary determination means (100) for determining a boundary (L) between a work site (A) and a processed work site (B), wherein the boundary determination means ( 100) is turf presence / absence information in which the turf presence / absence information sampled this time and the turf presence / absence information previously sampled at predetermined intervals are arranged at the predetermined intervals in the lateral direction of the vehicle body. In the array, for the lawn mowing work vehicle configured to correct the lawn presence information to the lawn absence information when there is no other lawn presence information in the vicinity of the lawn presence information in the lawn presence information sampled this time. Boundary detection Location. 2. The lawn mowing work vehicle boundary detection apparatus according to claim 1, wherein the border discrimination means (100) samples lawn presence / absence information sampled this time and subjected to the correction processing, and sampling before this time. In addition, a logical sum operation is performed on the grass presence information with respect to the detection information of the grass presence information that has been subjected to the correction processing one or more times at the predetermined intervals. A boundary detection device for a lawnmower configured to determine a boundary (L).