JP2003262520A - Direction detecting device and self-traveling cleaner loaded with it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the reliability of a direction detecting device used for a self-traveling moving body by simplifying the means. <P>SOLUTION: The direction detecting device of the self-traveling moving body has an optical sensor unit 1, an arithmetic means 7, and a storing means 9, all of which are loaded in the moving body. On the outside or the moving body, a light emitting means 5 is provided in a fixed state. A plurality of photoreceptor elements 2, 2, etc., is attached to the optical sensor unit 1. The light receivable ranges of adjacent photoreceptor elements partially overlap each other. The arithmetic means 7 detects the direction to the light emitting means 5 by comparing the intensities of the light rays received by means of the photoreceptor elements 2 with each other. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a direction detecting device, and more particularly to a direction detecting device suitable for a self-propelled cleaner or a self-propelled carriage.

[0002]

2. Description of the Related Art An example of a conventional position detecting device used for a self-propelled moving body is described in Japanese Patent Application Laid-Open No. 7-311041. In this position detecting device, in order to autonomously grasp the current position, two light receiving units are attached to a top surface of a moving body having driving wheels at positions separated by a predetermined distance in plan view. These light receiving parts are rotatable. At the same time, two light emitting parts are attached to the side surface of the reference station at positions separated by a predetermined distance in plan view. The amount of light received changes when the light receiving unit on the moving body turns while sampling. The relative position and the relative attitude angle are obtained based on the turning angle at which the amount of received light is the peak.

[0003]

In the position detecting method described in the above publication, since the movable body is provided with two sets of rotatable light receiving shafts, the structure of the light receiving portion is complicated. Therefore, when these photoreceptors are mounted on a household vacuum cleaner or the like, this is an obstacle to miniaturization.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object thereof is to miniaturize a direction detecting device mounted on a moving body. Another object of the present invention is to
It is to realize an inexpensive direction detection device.

[0005]

A feature of the present invention for achieving the above-mentioned object is that a direction detecting device is provided with a light-emitting body that emits light and is fixedly installed, and an optical sensor unit mounted on a moving body. In the optical sensor unit, a plurality of first light receiving means for receiving the light emitted from the light emitting body, second light receiving means having a narrower incident range than the first light receiving means, and these second light receiving means are provided. An arithmetic means for evaluating the amount of light received by the first and second light receiving means and a storage means for storing the amount of received light which is obtained in advance are provided, and the amount of light received stored in the storage means and the amount of light received calculated by the arithmetic means are provided. The relative direction between the moving body and the light emitting body is detected based on.

In this feature, in the optical sensor unit, a plurality of first light receiving means are arranged in the circumferential direction so that light from any direction can be received in the circumferential direction.
It is desirable that the arithmetic means determines the input from the second light receiving means to determine the relative direction between the optical sensor unit and the light emitter. Further, the moving body may be provided with means for detecting the moving amount of the moving body, and the moving body is rotated to update the light reception data of the first and second light receiving means stored in the storage means. You may do it. Further, the first and second
The light receiving means may be provided on the outer peripheral portion of the light receiving surface formed in a substantially cylindrical shape, and the second light receiving means may be provided in the traveling direction of the moving body or in the opposite direction.

As another feature to achieve the above object, the moving body is a self-propelled cleaner and the direction detecting device having any one of the above features is mounted.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a direction detecting device according to the present invention, which is mounted on a self-propelled cleaner, will be described below with reference to the drawings. FIG. 1 shows a schematic diagram of a self-propelled vacuum cleaner. An optical sensor unit 1 that emits infrared rays is attached to the top of the self-propelled cleaner 4. Self-propelled cleaner 4
The light emitting body 5 is fixed at a position away from. The optical sensor unit 1 includes a light receiving element 2 having a wide directional angle and a light receiving element 3 having a narrow directional angle in order to receive the modulated infrared ray 11 emitted from the light emitting body 5. The light reception intensity information of each of the light receiving elements 2 and 3 is sent to the calculation means 7 provided inside the self-propelled cleaner 4.

The calculation means 7 is connected to the control unit 6 of the drive system for driving the self-propelled cleaner 4. The drive system has a pair of drive wheels 10, and the calculation means 7 commands the drive system control unit 6 to determine the rotation speed and rotation amount of the drive wheels 10. When the drive wheels 10 rotate at the rotation speed and the rotation amount according to the command of the calculation means 7, the drive system control unit 6 sends information about the actual rotation speed and rotation amount of the drive wheels 10 to the calculation means 7. A cleaner unit 8 is provided at the lower front portion of the self-propelled cleaner 4, and sucks dust and the like scattered on the floor surface as the self-propelled cleaner 4 moves. The calculation means 7 is also connected to this cleaner section 8,
The operation and stop of the cleaner unit 8 are controlled. The calculation means 7 is further connected to the storage means 9. The storage unit 9 stores information about the relationship between the light receiving intensity of the light receiving element 2 having a wide directional angle and the attitude angle of the optical sensor unit 1 with respect to the light emitting body 5. The command information of the calculation means 7 and the information stored in the storage means are input from an input means (not shown) provided in the self-propelled cleaner 4 or a remote controller provided separately from the self-propelled cleaner 4. It

2 and 3 show the details of the optical sensor unit mounted on the self-propelled vacuum cleaner configured as described above. FIG. 2 is a perspective view of the optical sensor unit. The optical sensor unit 1 has a cylindrical shape, and a light receiving element 2 having a wide directional angle and a light receiving element 3 having a narrow directional angle are arranged on the outer peripheral portion thereof. FIG. 3 shows a cross-sectional view of the optical sensor unit 1. The light receiving element 2 having a wide directional angle is set at 60 degrees in the circumferential direction by 6 degrees.
Place them individually. The incident angle range in which each light receiving element 2 can receive light is
The infrared light 11 from the light-emitting body 5 can be detected in the range of an incident angle of 120 degrees or more, which is 60 degrees or more on each side from the optical axis. As a result, the infrared light 11 can be detected by any two adjacent light receiving elements 2 having a wide directional angle, regardless of the direction of the light emitter 5 in any direction of 360 degrees.

The light receiving element 3 having a narrow directional angle is provided at only one location in the circumferential direction, and is located between the light receiving elements 2 and 2 having a wide directional angle. A slit (not shown) is formed on the front surface of the light receiving element 3 having a narrow directional angle. This slit is
The range in which the infrared light 11 emitted by the light emitting body 5 can be received, that is, the direction and width of the incident angle is adjusted. As a result, the light receiving range of the light receiving element 3 having a narrow directional angle is set to the light receiving element 2 having a wide directional angle.
It is narrower than the light receiving range of.

FIG. 4 shows a top view of the self-propelled cleaner 4 shown in FIG. The optical sensor unit 1 includes two drive wheels 10
It is located right above the center of the. When one of the drive wheels 10 is rotated in the normal direction and the other is rotated in the reverse direction at the same speed, the self-propelled cleaner rotates on the spot around the optical sensor unit 1.

FIG. 5 shows the relationship between the sensitivity S of the light receiving element 2 having a wide directional angle to the infrared rays 11 and the incident angle θ. Light receiving element 2
The sensitivity has a peak when it is incident on the light receiving element 2 in a direction perpendicular to it, and the sensitivity sharply decreases as the incident angle deviates from the vertical direction. The light receiving range of the optical sensor unit 1 will be described with reference to FIGS. 6 and 7. At the position shown in FIG.
When is positioned, the two light receiving elements 2a and 2b having a wide directional angle can receive light. FIG. 5 shows the sensitivities S _2a and S _2b of the light receiving elements 2a and _2b at this time.

When the distance between the optical sensor unit 1 and the light emitter 5 is sufficiently large, it is considered that the distances from the respective light receiving elements 2a and 2b to the light emitter 5 are substantially equal. Therefore,
Since the distances to the light emitters 5 are substantially equal, each light receiving element 2
It is assumed that a and 2b are in the center of the optical sensor unit 1. Then, using the ratio of the light receiving intensities of the respective light receiving elements 2a and 2b, the light receiving intensity at the central portion of the optical sensor unit 1 is obtained, and the direction of the light emitting body 5 with respect to the optical sensor unit 1 is obtained.

Using this method, two or more of the light receiving elements 2 having a wide directional angle can receive light regardless of the direction of the light emitter 5. Therefore, the direction of the light emitting body 5 can be determined by selecting the two elements having the highest received light amounts and obtaining the ratio of the received light amounts. Furthermore, if it is possible to simultaneously detect the light receiving intensities of all the light receiving elements 2 having a wide directional angle arranged on the circumference,
The position of the light emitter 5 can be detected even while the self-propelled cleaner 4 is running.

The sensitivity characteristic of the light receiving element 3 having a narrow directional angle is shown in FIG.
Shown in. The thin solid line in FIG. 8 shows the sensitivity distribution characteristics when the slit is not formed, and the thick solid line shows the case where the slit is formed. FIG. 7 shows the manner in which the light emitting element 5 is detected by the light receiving element 3 having the narrow directional angle. By forming the slit, the light receiving element 3 having a narrow directional angle can receive only the infrared light from the light emitting element 5b which is incident substantially vertically. That is, as shown in FIG. 7, when the light emitting body 5 is the light emitting body 5a located in the direction away from the vertical plane of the light receiving element 3 having a narrow directional angle, the sensitivity is substantially 0 as shown in FIG.

The light receiving element 2 having a narrow directional angle is the infrared ray 11
It is determined whether the light emitter 5 is in the predetermined direction of the optical sensor unit 1 depending on whether or not is detected. The resolution of the light receiving element 2 having a narrow directional angle is determined by the range of the incident angle that can be detected by the light receiving element 2. Further, even if the characteristics of the light receiving element are symmetrical as shown by the thin line in FIG. 8, the range of incident angles at which light can be received is determined by the slit.

FIG. 9 shows an example in which the self-propelled cleaner 4 detects the light emitter 5 by using the light receiving element 3 having a narrow directional angle. The self-propelled cleaner 4 is rotated on the spot, and the direction in which the light receiving element 3 having a narrow directional angle detects the infrared rays 11 is regarded as the direction of the light emitter 5. When the light receiving range of the light receiving element 3 with a narrow directional angle is wider than the required resolution, the light receiving element 3 with a narrow directional angle detects the infrared rays 11 when the self-propelled cleaning device 4 is rotated on the spot. The intermediate direction between the two directions, the direction in which the infrared rays 11 cannot be detected and the direction in which the infrared rays 11 cannot be detected, is regarded as the direction of the light emitting body 5.

FIG. 10 shows the flow of information when detecting the direction of the light emitter 5. The calculation means 7 determines the presence or absence of light reception based on the amount of light received by the light receiving element 3 having a narrow directivity. Light receiving element 3
When it is determined that the light is being received, the light-emitting body 5 at that time
The direction of is stored as angle information and is used when planning a travel route. On the other hand, the received light intensity of the light receiving element 2 having wide directivity is converted into a comparable form for comparison with the direction detection database stored in the storage means 9. That is,
An evaluation function is determined from the ratio of the light receiving intensity of the element having the highest light receiving intensity among the light receiving elements 2 having wide directivity and the element having the second highest light receiving intensity, and compared with the stored value in the database. The evaluation function may be one having a one-to-one correspondence with the ratio of the received light intensity.

The value of the evaluation function and the information of which element the received light intensity was used to obtain the evaluation function are collated with the direction detection database. The direction detection database records the value of the evaluation function when the light emitter 5 is present in each direction and which element is used to obtain the evaluation function.
When collating the direction detection database with the evaluation function, the data of the element used for obtaining the value of the evaluation function is searched from the database. Next, the retrieved data is interpolated or extrapolated. Thereby, the direction corresponding to the value of the evaluation function is obtained. This direction is used when planning the travel route.

The wide-angle light receiving element 2 detects the direction of the light emitter 5 based on the data in the direction detection database. When the characteristics of the element change due to aging or dirt on the optical system, the direction detection database is rebuilt. FIG. 11 shows a flowchart for reconstructing the direction detection database.

In step 100, reconstruction is started. The light receiving element 3 having a narrow directional angle is used to detect the correct direction of the light emitter 5 (step 110). Next, the above evaluation function is calculated (step 120). The direction of the light-emitting body 5, the value of the evaluation function, and the number of the light-receiving element 2 having the wide directional angle used for obtaining the value of the evaluation function are stored in the storage means 9 (step 13).
0).

The self-propelled cleaner 4 is rotated on the spot by a predetermined angle. The angle of rotation at this time is obtained from the encoder attached to the drive wheel 10 (step 140). After starting the reconstruction of the direction detection database, it is determined whether or not the self-propelled cleaning device 4 has rotated 360 degrees or more in total (step 150). If it has rotated 360 degrees or more, the reconstruction of the direction detection database is terminated (step 160).
When the rotation of the self-propelled cleaner 4 is less than 360 degrees, the process returns to step 120. Hereinafter, the steps described above are repeated.

When the above operation is executed, the sensor 2 having a wide directional angle can accurately detect the direction of the light emitter 5. The direction detection database may be rebuilt by the user at will, or may be rebuilt every time the self-propelled cleaner 4 is activated. Further, when the light receiving element 3 having a narrow directional angle detects the direction of the light emitting body 5 and the light receiving element 2 having a wide directional angle also detects the direction of the light emitting body 5, the two types of light receiving elements 2 and 3 are detected. It may be automatically executed when the angle difference becomes large. In this case, a display prompting the user to rebuild the database may be displayed without rebuilding the database.

FIG. 12 shows a method of detecting the position with reference to the light emitter 5. Self-propelled vacuum cleaner 4 with luminous bodies 5c and 5d
Install in the environment of use. The infrared rays 11 and 11 emitted from the light emitters 5c and 5d are modulated with different modulation frequencies. The light emitting sources can be distinguished by the difference in the modulation frequency. The self-propelled cleaner 4 detects the direction of the light emitters 5c and 5d at the position A on the left side of the drawing. Distance L from this point A
An encoder (not shown) attached to the drive wheel 10 of the self-propelled cleaner 4 is used to measure that the self-propelled cleaner 4 has traveled to the position B that is distant to the right only.

At the position B, the directions of the light emitters 5c and 5d are detected again. By this operation, the directions of the light emitters 5c and 5d with respect to the moving direction of the self-propelled cleaner 4 are obtained. That is, the direction of the light emitter 5c at the position A is θAc, and the direction of the light emitter 5d at the position A is θAd.
The direction of c at position B is θBc, and the direction of the light-emitting body 5d at position B is θBd. From these angles and the moving distance L of the self-propelled cleaner 4, the relative positional relationship between the light emitters 5c and 5d and the self-propelled cleaner 4 can be obtained using the principle of triangulation. If the coordinates of the light emitters 5c and 5d are known, the coordinates of the positions A and B can be obtained.

In the above-mentioned embodiment, the self-propelled vacuum cleaner is taken as an example of the moving body, but it goes without saying that the present invention can be applied to an automatic guided vehicle and various self-propelled robots used in a factory. In the case of an unmanned guided vehicle, it is easy to find the position of the light emitting body, and the transport path is usually fixed, so that the guided vehicle can be positioned with high accuracy.

[0028]

As described above, according to the present invention, since the preset direction angle of the luminous body with respect to the moving body can be obtained by using the principle of triangulation, the number of movable parts of the direction detecting device can be reduced. Therefore, the reliability of the direction detecting device can be improved, and the direction detecting device can be realized at low cost.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an embodiment of a self-propelled vacuum cleaner according to the present invention.

FIG. 2 is a perspective view of an optical sensor unit used in the self-propelled cleaner shown in FIG.

3 is a cross-sectional view of the optical sensor unit of FIG.

FIG. 4 is a top view of the self-propelled vacuum cleaner shown in FIG.

FIG. 5 is a graph illustrating the sensitivity of the first light receiving unit.

FIG. 6 is a diagram illustrating a first light receiving unit.

FIG. 7 is a diagram illustrating a second light receiving unit.

FIG. 8 is a graph illustrating the sensitivity of the second light receiving unit.

FIG. 9 is a diagram for explaining the operation of the self-propelled cleaner shown in FIG. 1.

FIG. 10 is a block diagram illustrating the flow of information when a direction is detected.

FIG. 11 is a flowchart illustrating a procedure for reconstructing a direction detection database.

FIG. 12 is a view for explaining the operation of the self-propelled vacuum cleaner shown in FIG.

[Explanation of Reference Signs] 1 ... Optical sensor unit, 2, 2a, 2b ... Wide directional angle light receiving element (first light receiving means), 3 ... Narrow directional angle light receiving element (second light receiving means), 4 ... Moving Body 5, 5a, 5b, 5c,
5d ... Light emitter, 6 ... Drive system control unit, 7 ... Computing means, 9 ...
Storage means, 10 ... Drive wheels.

Continued front page    (72) Inventor Atsushi Ozeki             502 Kintatemachi, Tsuchiura City, Ibaraki Japan             Tate Seisakusho Mechanical Research Center (72) Inventor Search for Kagawa             502 Kintatemachi, Tsuchiura City, Ibaraki Japan             Tate Seisakusho Mechanical Research Center (72) Inventor Taiji Tajima             502 Kintatemachi, Tsuchiura City, Ibaraki Japan             Tate Seisakusho Mechanical Research Center F term (reference) 2F065 AA03 AA09 AA31 AA37 BB15                       CC00 DD02 FF09 FF17 FF41                       JJ05 JJ09 LL28 MM04 QQ25                 3B006 KA01                 3B057 DA04 DE02

Claims (6)

[Claims] 1. A direction detection device comprising a light-emitting body that emits light and is fixedly installed, and a light-sensor unit mounted on a moving body, wherein the light-sensor unit receives light emitted from the light-emitting body. A plurality of first light receiving means, a second light receiving means having a narrower incident range than the first light receiving means, and an operation for evaluating the amount of light received by the first and second light receiving means. Means and a storage means for storing the light reception amount obtained in advance, and a direction for detecting the relative direction between the moving body and the light emitting body based on the light reception amount stored in the storage means and the light reception amount calculated by the calculation means. Detection device. 2. In the optical sensor unit, a plurality of first light receiving means are arranged in the circumferential direction so that light from any direction can be received in the circumferential direction, and an input from the second light receiving means. 2. The direction detecting device according to claim 1, wherein the calculating means determines the relative direction between the light sensor unit and the light emitter. 3. The direction detecting device according to claim 1, wherein the moving body is provided with means for detecting a moving amount of the moving body. 4. The direction detecting device according to claim 1, wherein the light receiving data of the first and second light receiving means stored in the storage means is updated by rotating the moving body. . 5. The first and second light receiving means are provided on an outer peripheral portion of a light receiving surface formed in a substantially cylindrical shape, and the second light receiving means is provided in a traveling direction of a moving body or an opposite direction thereof. The direction detecting device according to claim 1, wherein the direction detecting device is provided in 6. A self-propelled vacuum cleaner in which the moving body is a self-propelled vacuum cleaner, and which is equipped with the direction detecting device according to claim 1.