JPH0943342A - Self position detector of autonomous traveling work vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the detection of accurate self position and the simultaneous detection of a reflection mark and an obstacle by obtaining distance information from reflected light, and also providing a means for measuring reflection intensity of light and a means for identifying an substance having reflected light. SOLUTION: A light scanning means 6 performs light scanning, and a distance/light reflection intensity measuring means 31 computes the reflectance of an object from the distance information and light reflection intensity obtained by receiving the pulse beam reflected with an outside object. This writes the distance information, the light reflection intensity, and information on reflectance into a memory to the scanning point coordinate. When the scanning of one face is completed, the identification means 32a extracts the points where the reflectance is not less than the set value from the data stored in the memory, and performs the histogram processing, and recognizes marks PA and PB, and a self vehicle position computing means 32b computes the present self vehicle position. Moreover, a peripheral obstacle information computing means 32c extracts the points where the reflectance is not more than the set value and besides the distance is not more than the set value from among the memory, and performs histogram processing, and judges the obstacle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention recognizes a plurality of markers installed around a specific work area to detect the self-position, and self-positions an autonomous traveling work vehicle that performs work traveling in grass cutting, lawn mowing, and the like. Regarding a detection device.

[0002]

2. Description of the Related Art Conventionally, for an autonomous vehicle that is autonomously autonomously traveling, there is a technique in which an electric wire is buried underground and a magnetic sensor detects a magnetic field generated by the electric wire as self-position detection for autonomous traveling. Although it has been proposed, if the autonomous driving area is large, such as an autonomous vehicle that performs unmanned grass cutting, lawn cutting, etc. in various fields such as golf courses, river banks, parks, etc. It is difficult to embed the electric wire, and the installation cost becomes large.

For this reason, a technique has been developed in which a plurality of signs are installed in the vicinity of an autonomously traveling area and the position of the vehicle is detected by recognizing the signs.
In Japanese Patent No. 5606, light is used as an example of an electromagnetic wave, and light is projected onto a plurality of retroreflective poles (light reflective markers) provided upright in a specific area, and the reflected light is received by an optical sensor, and adjacent reflective poles are received. There is disclosed a technique of detecting the angle at which the angle of view is detected and detecting the self-position by the three-point angle method (triangulation method) from the detected angle and the known coordinates of the sign.

[0004]

However, in the above-mentioned prior art, the light reflected sign is detected by receiving the light reflected by the light reflected sign by the optical sensor, and the self position is detected by triangulation. , At least three light-reflective signs are required for triangulation, and in autonomous driving work in which the traveling direction varies in the front-rear direction or the left-right diagonal direction, the space between the signs may differ depending on the positional relationship between the vehicle and the light-reflective signs. There is a possibility that the angle error of 1 becomes large and the measurement accuracy deteriorates.

Further, in an autonomous vehicle, it is necessary to consider an obstacle existing around the work area. However, conventionally, it is difficult to detect the obstacle and the light reflection sign at the same time, and In addition to the device for detecting the reflective sign, a device for detecting an obstacle must be provided, which causes a cost increase.

The present invention has been made in view of the above circumstances. Not only can the self-position be accurately detected while minimizing the number of reflective markers installed around the work area, but the reflective markers and obstacles can be detected. It is an object of the present invention to provide a self-position detecting device for an autonomously traveling work vehicle that can be detected simultaneously.

[0007]

According to the first aspect of the present invention,
In a self-position detecting device for an autonomous traveling work vehicle, which detects a plurality of reflective signs installed around a work area by electromagnetic wave scanning and measures the self-position, a scanning means is operated as shown in the basic configuration diagram of FIG. A distance / electromagnetic wave reflection strength measuring means for measuring the reflection strength of the detected electromagnetic wave as well as obtaining distance information based on the time from the projection of the electromagnetic wave to the outside until the detection of the electromagnetic wave reflected by the external object, and the above distance. Identification means for identifying whether the object reflecting the projected electromagnetic wave based on the information and the electromagnetic wave reflection intensity is the reflective sign or the surrounding obstacle, and when the reflective sign is identified, the distance information and the electromagnetic wave scanning position for the reflective sign. The direction and distance to the vehicle are calculated from the above, and the direction and distance information relating to at least two of the above-mentioned reflection signs are stored in advance as the above When the vehicle position calculating means for calculating the vehicle position based on the position information of the sign and the peripheral obstacle are identified, the distance information for the peripheral obstacle and the electromagnetic wave scanning position are used to detect the obstacle around the vehicle. A peripheral obstacle information calculation means for calculating a direction and a distance is provided.

According to a second aspect of the present invention, the identifying means identifies the object based on the distance information and the electromagnetic wave reflection intensity when the object reflecting the projected electromagnetic wave is identified as the reflective sign or the surrounding obstacle. The reflectance is calculated and the reflectance is used as an index for identification.

That is, according to the first aspect of the invention, based on the distance information based on the time from the projection of the electromagnetic wave to the outside until the detection of the electromagnetic wave reflected by the external object, and the reflection intensity of the detected electromagnetic wave. Then, the object reflecting the projected electromagnetic wave is identified as a reflective sign or a surrounding obstacle. When the identified object is a reflective sign, the direction and distance to the vehicle are calculated from the distance information for the reflective sign and the electromagnetic wave scanning position, and the direction and distance information relating to at least two of the reflective signs are stored in advance. The vehicle position is calculated on the basis of the position information of the above-mentioned reflection sign. Also, when the identified object is a peripheral obstacle,
The direction and distance of the surrounding obstacle with respect to the vehicle are calculated from the distance information about the surrounding obstacle and the electromagnetic wave scanning position.

In this case, in the invention described in claim 2, in the invention described in claim 1, distance information based on the time from the projection of the electromagnetic wave to the outside until the detection of the electromagnetic wave reflected by the external object, The reflectance of the object is calculated from the detected reflection intensity of the electromagnetic wave, and the reflectance is used as an index to identify whether the object reflecting the projected electromagnetic wave is a reflective sign or a peripheral obstacle.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. 2 to 7 relate to the first embodiment of the present invention, FIG. 2 is a flow chart of a self-position detection routine, FIG. 3 is a flow chart of a main control routine, and FIG. 4 is a lawn mowing vehicle and a light reflection sign. FIG. 5, FIG. 5 is a block diagram of a control system, FIG. 6 is an explanatory diagram of distance and light reflection intensity measurement, and FIG. 7 is an explanatory diagram of self-position detection in a work area.

In FIG. 4, reference numeral 1 represents an unmanned autonomous traveling work vehicle, which in the present embodiment is a lawn mowing work vehicle for performing grass / lawn mowing work on a golf course or the like,
Light is used as an example of an electromagnetic wave, and the self-position is detected by optical scanning. This lawnmower vehicle 1 is driven by an engine, and the steering angles of the front and rear wheels can be independently controlled.
At the bottom of the vehicle body, a cutting blade mechanism 2 such as a mower for performing grass / lawn mowing work is provided, a dead reckoning sensor for measuring the current position based on the traveling history, and a grass / lawn mowing work area. It is provided with a copy travel sensor for performing a copy travel along the trace boundary.

As the dead reckoning sensor, a geomagnetic sensor 3 and a wheel encoder 4 are adopted, and as the copy running sensor, a boundary between a cut portion and a non-cut portion in lawn mowing work is detected. The cut boundary detection sensor 5 is used. The cut boundary detecting sensor 5 is, for example,
It is configured by combining a sled-shaped plate that moves up and down according to the length of grass / turf, and a rotary encoder that detects a rotation angle of a member that supports the sled-shaped plate.

Further, in the lawnmower work vehicle 1, since a plurality of light reflection markers 20 standing upright around the grass / lawn mowing work area are recognized to detect the self position, a scanning section of a laser radar is used as a scanning means. 6 is installed in the front part of the vehicle body, and when there is a peripheral obstacle that obstructs traveling, this peripheral obstacle can be recognized at the same time as the light reflection sign 20. The light reflective sign 20 is a retroreflective sign having a property that light is always reflected in the incident direction. For example, a retroreflector such as a corner cube type light reflective sheet is attached over a predetermined length. It is attached and configured.

As shown in FIG. 5, the laser radar scanning unit 6 has a projector 7 for emitting a pulsed laser beam having a constant period, a converging lens 8 for converging the laser beam emitted from the projector 7 into a beam, A semi-transmissive mirror (half mirror) 9 that transmits the light from the converging lens 8 while reflecting the incident light from the outside, a scanning mirror 10 for scanning the light projected to the outside, and the scanning mirror 10 is rotated. A high speed scanning motor 11, a converging lens 12 for converging the incident light from the outside reflected by the half mirror 9, a light receiver 13 for receiving the light from the converging lens 12, and the like are provided. Scanning mirror 10 for vehicle body
A rotation angle sensor 14 for detecting the angle is attached.

The above-described sensors 3, 4, 5, 14, the light projector 7, the scanning motor 11, and the light receiver 13 are connected to a control device 30, which detects the self-position of the lawnmower vehicle 1. , Autonomous driving is controlled.

The control device 30 is composed of a plurality of microcomputers and the like, and operates the light projector 7 and the scanning motor 11 and inputs a signal from the light receiver 13 into a distance / light reflection intensity measuring section 31, The object recognition / position detection unit 3 to which the signal from the rotation angle sensor 14 and the information from the distance / light reflection intensity measurement unit 31 are input.
2, dead reckoning position detection unit 33 to which signals from the geomagnetic sensor 3 and the wheel encoder 4 are input, and cut boundary detection unit 3 to which signals from the cut boundary detection sensor 5 are input.
4 and the like, and further, a travel control unit 35 for performing travel control based on signals from the detection units 32, 33, 34, fixed data such as topographic data of the work area and position data of the light reflection sign. A work data storage unit 36 including a memory for storing, a memory for writing the position information of the object detected by the object recognition / position detection unit 32, a memory for storing work data in the middle of processing, and the traveling control unit 35.
A vehicle control unit 37 that controls the vehicle according to an instruction from the driver, and a drive control unit 38 for driving each mechanism unit of the lawn mowing work vehicle 1 based on the output from the vehicle control unit 37, a steering control unit 39, and a cutting blade control. A section 40 is provided.

As the distance / electromagnetic wave reflection intensity measuring means, in the distance / light reflection intensity measuring unit 31, the projector 7 of the laser radar scanning unit 6 is operated and the scanning motor 11 is operated at high speed to perform optical scanning, and the optical reflection is performed. The light reflection intensity is measured while measuring the distance to the sign 20 and the surrounding obstacles.

That is, as shown in FIG. 6, for example, the light projector 7 is composed of a laser diode and the light receiver 1 is provided.
3 is composed of a photodiode, pulsed light is emitted from the light projector 7 at a constant time interval, and pulsed light reflected by an external light reflection sign 20 or surrounding obstacles is received by the light receiver 13
To receive light. Then, the time td from light projection to light reception is measured based on each current I of the light projector 7 and the light receiver 13 to calculate the distance between the vehicle and the light reflection sign 20 or surrounding obstacle (for example, the distance Is obtained by multiplying the time td by a predetermined constant), and the intensity of the received pulsed light is measured to obtain the reflection intensity of the object.

As shown in FIG. 1, the object recognizing / position detecting unit 32 detects that the object reflecting the light projected based on the distance information and the light reflection intensity from the distance / light reflection intensity measuring unit 31 is the light. When the identification means 32a for identifying the reflective sign 20 or the surrounding obstacle, the light reflective sign 20 is identified, the direction and the distance to the vehicle are calculated from the distance information and the optical scanning position for the light reflective sign 20, and at least Own vehicle position calculating means 32 for calculating the own vehicle position based on direction and distance information relating to the two light reflecting signs 20 and position information of the light reflecting signs 20 stored in advance.
b, and when the peripheral obstacle is identified, the function as the peripheral obstacle information calculating means 32c for calculating the direction and the distance of the peripheral obstacle with respect to the own vehicle from the distance information and the optical scanning position for the peripheral obstacle. The stored data is stored in the work data storage unit 36 for each scanning position based on the signal from the rotation angle sensor 14, and the distance information and the light reflection intensity information from the distance / light reflection intensity measurement unit 31 are stored. The position information of the object is extracted from this to recognize the light reflection sign 20 and surrounding obstacles (not shown), and calculate the vehicle position.

In the dead reckoning position detecting section 33, the vehicle speed detected by the wheel encoder 4 is integrated to obtain the traveling distance, and the traveling distance is accumulated corresponding to the change in the traveling direction detected by the geomagnetic sensor 3. By
The vehicle history is calculated from the reference point and the vehicle position is measured.

On the other hand, the cut boundary detecting section 34 processes the signal from the cut boundary detecting sensor 5 according to the grass / turf height to detect the grass / turf boundary position. As described above, the cut boundary detecting sensor 5 is composed of a sled-shaped plate that moves up and down according to the grass / turf height, and a rotary encoder that detects a rotation angle of a member that supports the sled-shaped plate. If
When the vertical displacement of the sled-shaped plate corresponding to the grass / turf height is converted into a rotation angle and the detection signal from the rotary encoder is input, the above-mentioned cut boundary detection unit 34 detects the grass / grass from this detection signal. The lawn mowing work area and the non-working area are distinguished from each other to detect a cut boundary, and the position data thereof is output to the traveling control unit 35.

In the traveling control section 35, the object recognition /
Based on the information from the position detection unit 32, the dead reckoning position detection unit 33, and the cut mark boundary detection unit 34, a map of the work data storage unit 36 (work content and terrain data of a work area where grass / lawn mowing work is performed) Etc.), calculate the amount of error between the current position of the vehicle and the target position, and determine the driving route instruction and vehicle control instruction to correct this amount of error.
It is output to the vehicle control unit 37.

The vehicle control unit 37 converts the instruction from the traveling control unit 35 into a specific control instruction amount, and the control instruction amount is driven by the drive control unit 38, the steering control unit 39, and the cutting blade control unit 40. Output to. As a result, the drive control unit 3
8, the hydraulic motor 15 is driven to generate hydraulic pressure for driving each mechanism section of the lawnmower working vehicle 1, and the steering control section 39
Then, the front wheel steering mechanism and the rear wheel steering mechanism (not shown) are respectively servo-controlled via the front wheel steering hydraulic control valve 16 and the rear wheel steering hydraulic control valve 17, respectively, and the cutting blade control section 40 The cutting blade mechanism 2 is servo-controlled via the cutting blade control hydraulic control valve 18.

Incidentally, regarding the cut boundary detection using the above-mentioned cut boundary detection sensor, the servo control for the front wheel steering mechanism and the rear wheel steering mechanism, etc., by the present applicant, JP-A-7-147.
This is described in detail in Japanese Patent Publication No. 804.

A case where unmanned grass / lawn mowing work is performed on the work area 50 as shown in FIG. 7 will be described below. In this case, the lawn mowing work vehicle 1 is
Work area 5 is assumed to have been moved from an arbitrary preparation position to the start point 51 of grass / lawn mowing work by manned operation in advance.
The grass and lawn mowing work at 0 is autonomously performed according to the programs shown in the flowcharts of FIGS. After the work is completed, the work is moved from the work end point 53 to the standby position again by manned driving.

Incidentally, two light reflection markers PA and PB are installed on the same side around the work area 50, and these light reflection markers PA and PB are the same as those of the above-mentioned light reflection marker 20. In the following, the labels PA and PB will be simply referred to.

First, in the main control routine shown in FIG. 3, in step S101, a self-position detecting routine shown in FIG. 2 which will be described later is executed to recognize the markers PA and PB and measure the self-position.
When it is confirmed that the lawn mowing vehicle 1 has reached the starting point 51 of the grass / lawn mowing operation, in step S102 the hydraulic control valve 18 for controlling the cutting blade is opened to supply the hydraulic pressure to the cutting blade mechanism section 2. , Operate the cutting blade to start grass and lawn mowing work.

Next, the process proceeds to step S103, and the lawn mowing work is 1
It is checked whether or not it is the first time, and if the work is the first stroke (first column), the process proceeds to step S104, and if it is the second or later second column, the process branches to step S109.

This is the first operation, and when the process proceeds from step S103 to step S104, the self-position detecting routine is executed again to measure the position of the own vehicle by the sign recognition, and the position and traveling direction of the own vehicle by dead-reckoning navigation. After setting, the work data storage unit 36 is referred to in the subsequent step S105, and the amount of error from the current position is obtained with the end point position of the first time (first row) in the work area as the target position.

Next, when proceeding to step S106, the above step
Each target steering amount of the front and rear wheels is determined according to the error amount obtained in S105, and in the subsequent step S107, the front wheel steering mechanism is operated via the front wheel steering hydraulic control valve 16 and the rear wheel steering hydraulic control valve 17. The rear wheel steering mechanism is driven to control the target steering angle. When a surrounding obstacle is detected in the self-position detecting routine in step S104, the steering angle control for avoiding the obstacle is performed.

Then, in step S108, it is checked whether or not the lawn mowing vehicle 1 has reached the end point position of the first time (first row),
When the end point position is not reached, the above-mentioned step S104
Return to and continue grass and lawn mowing work, and when the end point is reached,
In step S116, it is checked whether or not all the work has been completed. In this case, since it is the first work, the above steps
Return to S103, check again whether it is the first work operation, work 2
After the first time, the process branches to step S109 to follow the work path 52 along the cut boundary.

That is, in step S109, when the vehicle body is laterally shifted by the width of the cutting blade and moved to the next work position, the cut mark boundary detection sensor 5 detects the cut mark boundary of the previous work in step S110, and in step S111. , The amount of error for realizing the set lawn mowing overlap amount is calculated by comparing the cut mark boundary with the vehicle position.

In the following step S112, the above step S111
Each target steering amount of the front and rear wheels is determined according to the error amount obtained in step S113, and in step S113, the front wheel steering hydraulic control valve 1
6, front wheel steering mechanism via the rear wheel steering hydraulic control valve 17,
The rear wheel steering mechanism is driven to control the target steering angle.

Then, in step S114, a self-position detecting routine, which will be described later, is executed to measure the position of the own vehicle by sign recognition, and the position and the traveling direction of the own vehicle are set by dead reckoning. It is checked whether the vehicle 1 has reached the end point position after the second time (after the second row), and if it has not reached the end point position, the above-mentioned step S110 is performed.
Returning to step S115, the copying traveling along the cut boundary is continued, and when the end point position after the second time (after the second row) is reached, step S115 is performed.
From step S116, it is determined whether or not the grass / lawn mowing work in the work area 50 is completed.

If the grass / lawn mowing work in the work area 50 is not completed, the process returns from step S116 to step S103 to continue the work. When the grass / lawn mowing work in the work area 50 is completed, this main control routine is executed. Stop grass and lawn mowing work and stop the vehicle.

Next, the self-position detecting routine by the sign recognition shown in FIG. 2 will be described.

In this self-position detection routine, first, in step S201, the projector 7 of the laser radar scanning unit 6 emits pulsed light of a constant cycle and the scanning motor 11
Is operated to input the angle signal from the rotation angle sensor 14 attached to the scanning motor 11, and step S2
At 02, the scanning point coordinates (H) on the plane are calculated from this angle signal.

Next, in step S203, when the distance information and the light reflection intensity obtained by receiving the pulsed light reflected by an external object with the light receiver 13 are input, step S204
Then, the reflectance of the object is calculated from the measured distance information and the light reflection intensity as an index for distinguishing the markers PA and PB from the obstacle, and in step S205, it corresponds to the scanning point coordinate (H). The distance information, the light reflection intensity, and the reflectance information are written in the memory.

Thereafter, the process proceeds to step S206, and it is checked whether or not the angle signal from the rotation angle sensor 14 makes one round to complete the scanning of the scanning motor 11 for one rotation (scanning of one surface).
When the rotation scanning is not completed, the above step S2
Returning to 01, the scanning is continued, and when the scanning for one rotation is completed, the process proceeds to step S207.

In step S207, a point whose reflectance is greater than or equal to a set value is extracted from the data stored in the memory, and step S2
At 08, for each small area on the scanning point coordinates, histogram processing is performed in which the number of extraction points whose reflectance is greater than or equal to the set value is the frequency, and the small area with the frequency is greater than or equal to the set value is extracted and the two markers PA, P
Identify and recognize B. Then, proceed to step S209,
The center of each small area corresponding to each of the markers PA and PB is obtained and used as the direction to the vehicle, and the average distance of each small area is calculated to calculate the distance between each of the markers PA and PB and the vehicle.

That is, when the number of points having a high reflectance on the scanning point coordinates is more than the set number, the points are labeled PA,
It is judged as the information by PB, the center of those points is calculated and used as the direction of the sign for the own vehicle, and the average value of the distance information written on the solid points is calculated and used as the distance between the own vehicle and the sign. is there.

Next, in step S210, the positions of the markers PA and PB stored in advance in the memory and the above-mentioned step
The current vehicle position (X, Y) is calculated from the direction and distance calculated in S209. In this case, two labeled PA, P
The point determined by the distance from B is as shown in FIG.
Although there are two locations on the plane, the markers PA and PB are arranged so as to be offset to one side of the work area 50, so that the two center points on the scanning line corresponding to the two markers PA and PB. It is possible to always obtain one point in the work area from the approximate angular relationship of.

After calculating the position (X, Y) of the own vehicle, the process proceeds to step S211, and the distance information, the light reflection intensity, and the reflectance information are written in correspondence with the scanning point coordinates (H). From the memory, points whose reflectance is less than or equal to a set value and distances are less than or equal to the set value are extracted, and in step S212, histogram processing of the extracted points is performed for each small area formed by the distance information and the scanning point coordinates. I do. Then, a small area with a frequency equal to or higher than the set value is extracted, it is determined to be a surrounding obstacle, the direction and distance with respect to the own vehicle are calculated, written in the memory, and the routine is exited.

Thus, the position and direction of the vehicle can be detected in real time, and the position of the vehicle can be accurately measured without being affected by the angle error between the light reflection markers. In this case, it is sufficient to use at least two light-reflecting markers, and since the light-reflecting markers and obstacles can be detected at the same time, the total cost can be reduced.

8 to 10 relate to the second embodiment of the present invention, FIG. 8 is a block diagram of a control system, FIG. 9 is a flow chart of a self-position detecting routine, and FIG. It is explanatory drawing which shows a scanning locus.

In this embodiment, the scanning function of the laser radar is slightly changed from the first embodiment described above, and the plane scanning of the first embodiment by the uniaxial rotation of the scanning mirror 10 is carried out. Is a three-dimensional scan by the biaxial rotation of the scanning mirror 10 to enlarge the scanning area.

Therefore, as shown in FIG. 8, in the laser radar scanning unit 6A of the present embodiment, the projector 7, the photoreceiver 13, the converging lenses 8 and 12, the half mirror 9 and the scanning mirror 10 are the same as those described above. Similar to the first embodiment,
A first scanning motor 11a for rotating the scanning mirror 10 is attached to a sub-frame 19a, and this sub-frame 19a is connected to a second scanning motor 11b via a slip ring 19b which is a signal joint.

A first rotation angle sensor 14a for detecting a rotation angle of the scanning mirror 10 with respect to the sub-frame 19a is attached to the first scanning motor 11a, and a light for a vehicle is attached to the second scanning motor 11b. A second rotation angle sensor 14b that detects a scanning surface angle is attached.

Corresponding to the function of the laser radar scanning unit 6A, the control device 30A according to the present embodiment includes the distance / light reflection intensity measuring unit 31 and the object recognition / detection unit according to the first embodiment. A distance / light reflection intensity measurement unit 31A and an object recognition / position detection unit 32A, which are slightly different from the position detection unit 32, are provided, and the distance / light reflection intensity measurement unit 31A allows the projector 7 and the first and second scanning motors 11a, 11b is activated and the signal from the light receiver 13 is processed, and
By the object recognition / position detection unit 32A, the rotation angle sensor 14
Signals from a and 14b and distance / light reflection intensity measuring unit 31
The information from A is to be processed. Other functions are the same as those in the first embodiment.

Then, while rotating the second scanning motor 14b at a low speed to change the vertical angle of the optical scanning, the first scanning motor 14a is rotated at a high speed to change the horizontal angle of the optical scanning. For example, as shown in FIG. 10, it is possible to perform scanning within a range of vertical angles of +30 to -30 deg and horizontal angles of 0 to 360 deg.

In this embodiment, in contrast to the main control routine of the first embodiment (see FIG. 3), the self-position detecting routine of FIG. 9 is executed to recognize the light reflection sign or the obstacle. .

In the self-position detecting routine of FIG. 9, in step S301, the projector 7 of the laser radar scanning unit 6A emits pulsed light of a constant cycle, and the first and second scanning motors 11a and 11b are operated. Each scanning motor 11
The angle signals θA and θB from the first and second rotation angle sensors 14a and 14b attached to a and 11b are input, and in step S302, the horizontal coordinate H is obtained from these angle signals θA and θB. The scanning point coordinates (H, V) consisting of the vertical coordinates V are calculated.

Next, in step S303, the distance information and the light reflection intensity obtained by receiving the pulsed light reflected by the external object with the light receiver 13 are input, and in step S304, the measured distance information and When the reflectance of the object is calculated from the light reflection intensity, distance information, light reflection intensity, and reflectance information are written in the memory corresponding to the scanning point coordinates (H, V) in step S305.

After that, the process proceeds to step S306, and it is determined whether or not the angle signal θB from the second rotation angle sensor 14b makes one round and the one-time scanning (one-side scanning) by the second scanning motor 11b is completed. When the scanning of one rotation is not completed, the process returns to step S301 to continue the scanning, and when the scanning of one rotation is completed, the process proceeds to step S307.

Then, in steps S307 to S312 similar to steps S207 to S212 in the above-described first embodiment, points having a reflectance of a set value or more are extracted from the data stored in the memory and histogram processing is performed. After recognizing the signs PA, PB by calculating the present vehicle position (X, Y), the points where the reflectance is equal to or less than the set value and the distance is equal to or less than the set value are extracted from the memory and the histogram is obtained. Perform processing to determine obstacles.

This embodiment not only has the same effects as the above-described first embodiment, but also performs optical scanning in the entire horizontal and vertical directions, so that the vehicle is tilted due to unevenness of the ground or the like. Even then, there is an advantage that the self-position can be accurately measured without losing sight of the light reflection sign.

In each of the embodiments, light is used as an example of an electromagnetic wave in order to obtain the vehicle position and surrounding obstacle information, but it goes without saying that an electromagnetic wave may be used as the electromagnetic wave. .

[0059]

As described above, according to the present invention, the distance information based on the time from the projection of an electromagnetic wave to the outside until the detection of the electromagnetic wave reflected by an external object, and the reflection intensity of the detected electromagnetic wave. Based on the above, the object that reflected the projected electromagnetic wave is identified as a reflective sign or a surrounding obstacle, and when the identified object is a reflective sign, the direction to the vehicle is determined from the distance information for the reflective sign and the electromagnetic wave scanning position. And the distance are calculated, and the vehicle position is calculated based on the direction and distance information relating to at least two of the reflective signs and the position information of the reflective signs stored in advance. If it is an object, it is installed in the vicinity of the work area in order to calculate the direction and distance of the surrounding obstacle with respect to the vehicle from the distance information for this surrounding obstacle and the electromagnetic wave scanning position. While it is possible to accurately detect the self-position while minimizing the number of reflective markers to be performed, it is possible to detect the reflective marker and the obstacle at the same time, and it is not necessary to provide another device for detecting the obstacle, The total cost can be reduced.

In identifying whether the object reflecting the projected electromagnetic wave is a reflective sign or a peripheral obstacle, the electromagnetic wave is projected from the outside until the electromagnetic wave reflected by the external object is detected. The reflectance of the object is calculated from the distance information based on time and the reflection intensity of the detected electromagnetic wave, and this reflectance is used as an index, so that it is possible to prevent erroneous recognition of the reflective sign and accurately detect the self-position. It is possible to obtain excellent effects.

[Brief description of drawings]

FIG. 1 is a basic configuration diagram of the present invention.

FIG. 2 is a flowchart of a self-position detection routine according to the first embodiment of the present invention.

FIG. 3 is a flowchart of a main control routine same as above.

FIG. 4 is an explanatory view showing a lawn mowing vehicle and a light reflection sign.

[FIG. 5] Same as above, block diagram of control system

FIG. 6 is an explanatory diagram of measuring distance and light reflection intensity as above.

FIG. 7 is an explanatory diagram of self-position detection in the work area of the same.

FIG. 8 is a block diagram of a control system according to a second embodiment of the present invention.

FIG. 9 is a flowchart of a self-position detection routine of the same as above.

FIG. 10 is an explanatory diagram showing optical scanning loci for vertical angle and horizontal angle in the same as above.

[Explanation of symbols]

1 ... lawn mowing work vehicle (autonomous traveling work vehicle) 6, 6A ... laser radar scanning unit (scanning means) 20, PA, PB ... light reflection sign 30, 30A ... control device 31, 31A ... distance / light reflection intensity measurement unit ( Distance / electromagnetic wave reflection strength measuring means) 32, 32A ... Object recognition / position detection section 32a ... Identification means 32b ... Rotation vehicle position calculation means 32c ... Surrounding obstacle information calculation means

Claims (2)

[Claims] 1. In a self-position detecting device for an autonomously traveling work vehicle, which detects a plurality of reflective markers installed around a work area by electromagnetic wave scanning and measures the self-position, a scanning means is operated to project an electromagnetic wave to the outside. Distance / electromagnetic wave reflection strength measuring means for measuring the reflection strength of the detected electromagnetic wave as well as obtaining the distance information based on the time from when the electromagnetic wave reflected by an external object is detected to the distance information and the electromagnetic wave reflection strength. Identification means for identifying whether the object reflecting the projected electromagnetic wave is the reflective sign or the surrounding obstacle, and when the reflective sign is identified, the distance to the reflective sign and the electromagnetic wave scanning position are used to determine the direction and direction to the vehicle. The distance information is calculated, and the direction and distance information relating to at least two of the reflective signs and the position information of the reflective signs stored in advance are stored. When the own vehicle position calculating means for calculating the own vehicle position based on and the above-mentioned surrounding obstacles are identified, the direction and distance of the surrounding obstacles with respect to the own vehicle are determined from the distance information and electromagnetic wave scanning position for the surrounding obstacles. A self-position detecting device for an autonomously traveling work vehicle, comprising: peripheral obstacle information calculating means for calculating. 2. The identifying means calculates the reflectance of the object from the distance information and the electromagnetic wave reflection intensity when identifying that the object reflecting the projected electromagnetic wave is the reflective sign or the surrounding obstacle. The self-position detecting device for an autonomously traveling work vehicle according to claim 1, wherein the reflectance is used as an index for identification.