JPH0467609B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a position measuring device for a moving body, and more particularly to a device for measuring the current position of a moving body using reflection of light.

[Prior Art] Conventionally, as a device for measuring the current position of a moving object such as a car or an unmanned mobile guided vehicle in a factory, for example, radio wave transmission sources are installed at multiple locations on the ground.
There was a device that received the radio waves on a moving object and calculated the current position of the moving object from the receiving direction.

[Problems to be Solved by the Invention] The position measuring device using radio waves as described above has a problem in that it is expensive because it requires a plurality of transmitting devices. Another problem was that frequent inspections and maintenance were required to ensure that the transmitting device always operated normally. In particular, when used outdoors, the installation environment of the transmitting device becomes harsh, which increases the frequency of inspection and maintenance. Furthermore, since the position measuring device described above uses radio waves, there are also problems in that it is subject to regulations under the Radio Law and is affected by radio wave noise.

Therefore, an object of the present invention is to provide a position detection device for a moving object that has a simple and inexpensive configuration, requires little inspection or maintenance, and is not subject to any regulations under the Radio Law.

[Means for Solving the Problems] The present invention provides first and second light reflecting means at predetermined coordinate positions on the right and left sides of the route along which the moving body should travel, and the light reflecting means is The current position of the moving body is measured by rotating and scanning a beam toward a reflecting means and detecting the reflected light, and includes an azimuth measuring means, a rotating scanning means, a photodetector, It includes an angle detection means, a data acquisition means, and a calculation means. 1st and 2nd
The light reflecting means has an optical property of reflecting the incident light in the same direction as the incident direction. The azimuth measuring means is for measuring the traveling azimuth of the moving object with respect to a predetermined reference azimuth. The rotational scanning means is for rotating and scanning the light beam from the moving body. The photodetector is for detecting light emitted from the rotating scanning means and reflected by the first or second light reflecting means. The angle detection means is for detecting the rotation angle of the rotation scanning means. The data acquisition means is for acquiring angle data from the angle detection means in response to the detection output of the photodetector. The calculation means is for calculating the current position of the moving body based on the traveling direction measured by the direction measurement means and the angle data taken in by the data acquisition means.

[Function] In the present invention, since the coordinate positions of the first and second light reflecting means are known in advance, the moving direction of the moving object with respect to the reference direction is measured, and the current position of the moving object and the first and second light reflecting means are known. By measuring the angular relationship with the second light reflecting means, the calculating means can calculate the current position of the moving body from the geometrical relationship based on the measured results.

[Embodiment] FIG. 1 is an illustrative diagram showing an outline of an embodiment of the present invention. In the figure, light reflecting means 2R and 2L are provided on the right and left sides of the road 1, respectively. These light reflecting means 2R and 2L have an optical property of reflecting the incident light in the same direction as the incident direction, and for example, a corner cube or the like is used. In addition, the light reflecting means 2R
and 2L are selected such that a line segment d connecting them is orthogonal to a predetermined reference direction X. This reference direction X may be selected to be parallel to the road 1, for example, or may be selected to correspond to north, south, east, west, etc., regardless of the direction in which the road extends.

On the other hand, a moving body 3 such as a car is provided with a direction measuring scanner 4 for measuring its traveling direction Y and a position measuring scanner 7 for measuring its current position. The direction measuring scanner 4 emits light beams 5R and 5L in the right and left directions orthogonal to the traveling direction Y of the moving body 3. The position measuring scanner 7 is for rotating and scanning the light beam 8 around the moving body.

FIG. 2 is a diagram showing the internal structure of the direction measurement scanner 4 shown in FIG.
It shows the state seen from the front. In the figure,
The direction measuring scanner 4 includes a pair of left and right light emitting/receiving units 4L and 4R. The light emitting/receiving unit 4L is for emitting light to the left side of the moving body 3, and the light emitting/receiving unit 4R is for emitting light to the right side of the moving body 3. Since these light emitting/receiving units 4L and 4R have the same bilaterally symmetrical structure, the right light emitting/receiving unit 4R will be explained here as a representative. A light source 42R, a lens 43R, and a half mirror 44R are housed inside the lens barrel 41R. As the light source 42R, a light source that emits a laser beam or the like with sharp directivity is used. The lens 43R converts the light emitted from the light source 42R into a planar light beam 5 that spreads in the vertical direction.
This is to make it R. The purpose of using such a planar beam is to ensure that the light beam 5R hits the light reflecting means 2R even if the moving body 3 vibrates to some extent. The light beam 5R exiting the lens 43R passes through a half mirror 44R and is emitted to the outside. Further, the half mirror 44R reflects the reflected light 6R from the light reflecting means 2R. A light receiver 45R is provided at a position where the reflected light from the half mirror 44R can be detected. This light receiver 45R uses, for example, a photodiode or a phototransistor, and derives a detection signal in response to receiving reflected light from the half mirror 44R.

FIG. 3 is a diagram showing the internal structure of the position measuring scanner 7 shown in FIG. 1, and shows the position measuring scanner 7 viewed from the front. In the figure, a lens barrel 71 is housed and held inside a housing 70. A light source 72, a lens 73, and a half mirror 74 are housed inside this lens barrel 71. As the light source 70, a light source that emits a sharply directional light such as a laser beam is used.
The lens 73 is for expanding the light emitted from the light source 72 in the vertical direction to form a planar light beam 8. The reason why such a planar light beam 8 is used is to ensure that the light beam 8 hits the light reflecting means 2R and 2L even if the moving body 3 vibrates to some extent. The light beam 8 exiting the lens 73 passes through a half mirror 74 and is emitted to the outside.
Further, the half mirror 74 receives and reflects the reflected light from the light reflecting means 2R and 2L. A light receiver 7 is placed at a position where it can detect the reflected light of this half mirror 74.
5 is provided. This light receiver 75 uses, for example, a photodiode or a phototransistor, and derives a detection signal in response to receiving the reflected light from the half mirror 74. Further, the housing 70 is connected to an encoder 76 and a motor 77. The motor 77 rotationally scans the light beam 8 around the moving body 3 by rotating the housing 70 . The encoder 76 is the light beam 8
The reference angle is selected to match the traveling direction Y of the moving body 3.

FIG. 4 is a schematic block diagram showing the direction measuring device mounted on the moving body 3. As shown in FIG. 5 and 6 are illustrative views for explaining the operation of the direction measuring device shown in FIG. 4. FIG. The configuration and operation of the direction measuring device shown in FIG. 4 will be described below with reference to FIGS. 5 and 6.

Now, as shown in FIG. 6, it is assumed that the moving direction Y of the moving body 3 is at an angle of θ with respect to the reference direction X. In this case, as shown in FIG. 5, the light beam 5L from the left light projecting/receiving unit 4L first hits the light reflecting means 2L. Since the light reflecting means 2L reflects the received light beam 5L in the same direction as the incident direction,
The reflected light returns to the half mirror 44L, and is reflected by the half mirror 44L to the light receiver 45.
incident on L. In response, the light receiver 45L derives a detection output and supplies the detection output to the first-come-first-served discriminating circuit 10 and to the flip-flop 12 via the OR gate 11. This flip-flop 1
2 is used to derive a set output with the first input and a reset output with the next input, so it is set by the output of the light receiver 45L that first detects the reflected light. The set output (high level) of flip-flop 12 is applied to AND gate 13 to enable it, and is inverted to low level and applied to AND gate 14 to disable it.
Accordingly, the pulses generated from the pulse generator 15 are applied to the counter 16 via the AND gate 13, so that the counter 16 counts the number of applied pulses. Here, the pulse generator 15 generates a pulse every time the movable body 3 advances a predetermined unit distance, and for example, a rotary encoder or the like that detects the rotation of the wheels of the movable body 3 is used. Therefore, by counting the number of output pulses from the pulse generator 15, the traveling distance of the moving object 3 can be measured.

When the moving body 3 travels a little and reaches the position shown by the dotted line in FIG. 5, the light beam 5R from the light projecting/receiving unit 4R hits the light reflecting means 2R. Therefore, the reflected light from the light reflecting means 2R returns to the half mirror 44R, is reflected by the half mirror 44R, and enters the light receiver 45R. Accordingly, the receiver 45R
derives a detection output, and supplies the detection output to a first-come-first-served discrimination circuit 10 and to a flip-flop 12 via an OR gate 11. Since the output of the photodetector 45R is the second signal, the flip-flop 12 inverts its output logic state and derives a low level signal from the set output terminal and a high level signal from the reset output terminal.
Accordingly, AND gate 13 is disabled and
AND gate 14 is activated. Therefore,
The counter 16 is the number n of pulses correlated to the distance l traveled by the moving body 3 from when the light receiver 45L detects the reflected light until the time when the light receiver 45R detects the reflected light.
is counted, and the counted value n is applied to one input of the division circuit 17 via the AND gate 14. Also, the reset output of flip-flop 12 is output to timer 18.
It is given as a reset signal to the counter 16 after a certain time delay determined by .

The other input of the division circuit 17 is given the setting value nw of the interval setting section 19. A value nw that correlates to the distance dl between the light reflecting means 2R and 2L is set in advance in the interval setting section 19. That is, the number of pulses that would be obtained from the pulse generator 15 if the moving object 3 traveled the distance dl is preset in the interval setting section 19. Therefore,
The division circuit 17 divides the count value n of the counter 16 by a set value nw (n/nw) that correlates with the mounting interval of the light reflection lenses 2R and 2L to obtain sin θ'. This angle θ' is as shown in FIG.
This is the angle that the light beams 5L and 5R make with respect to the line segment d that connects the moving body 3 with respect to the reference direction
is equal to the angle θ formed by the traveling direction Y of . Therefore, the division circuit 17 calculates sin θ. Division circuit 1
The output of 7 is given to a conversion circuit 20, and sin θ is converted into angle θ. Although not shown, the conversion circuit 20 includes a ROM in which each antilogous value (sine value) of sinθ (0≦θ<90°) is set at each address, and the division value (n/ The angle θ is configured to read out an angle θ corresponding to an antilogous number equal to nw). Angle θ derived from conversion circuit 20
is an absolute value, and it is not clear whether the angle θ is positive or negative with respect to the reference direction X. Therefore, for the purpose of determining whether the angle θ is positive or negative, the conversion circuit 20
The output is given to the positive/negative discrimination circuit 21.

The first arrival determination circuit 10 determines which of the detection outputs of the light receiver 45R and the light receiver 45L came first, and provides the first arrival determination output to the positive/negative determination circuit 21. The positive/negative determining circuit 21 determines whether the angle θ is positive or negative based on the output of the first arrival determining circuit 10. That is, the positive/negative discrimination circuit 21
When the first-arrival discrimination circuit 10 determines that the detection output of R has preceded, the first-arrival discrimination circuit 10 determines that the angle θ is negative (-), and that the detection output of the light receiver 45L has preceded.
When it is determined that the angle θ is positive (+), the angle θ is determined to be positive (+).
For example, when the moving object 3 travels as shown in FIG. 5, the light receiver 45L derives the detection output first, so the first-come-first-served discrimination circuit 21 determines the angle θ as positive (+) and outputs +θ. .

As described above, according to the azimuth measuring device shown in FIG. 4, it is possible to accurately measure the angle θ that the traveling azimuth Y of the moving object 3 makes with respect to the reference azimuth X.

FIG. 7 is a schematic block diagram showing a position measuring device mounted on the moving body 3. As shown in FIG. In the figure, the differentiating circuit 22 is given the output of the light receiver 75 shown in FIG. The output of this differentiating circuit 22 is applied to a T-type flip-flop 23. The T-type flip-flop 23 is configured such that its output is inverted every time a differential pulse is input from the differentiating circuit 22. The Q output of the T-type flip-flop 23 is AND
The signal is applied to one input of the gate 24 and is inverted and applied to one input of the AND gate 25. The output of the waveform shaping circuit 26 is applied to the other input of the AND gates 24 and 25.
This waveform shaping circuit 26 is a circuit for shaping the waveform of the output of the encoder 76 shown in FIG. 3 into a pulse signal. The outputs of AND gates 24 and 25 are:
are applied to registers 27 and 28, respectively. The outputs of registers 27 and 28 are given to arithmetic circuit 29. In addition, the arithmetic circuit 29 includes
Direction information is provided from a positive/negative discrimination circuit 21 shown in FIG. The arithmetic circuit 29 is for calculating the current position of the moving body based on the given data or information, and its output is given to the utilization device 30. As the utilization device 30, various devices such as an autopilot device and a display device can be considered.

8 and 9 are diagrams for measuring the operation of the measuring device shown in FIG. 7, and in particular, FIG. 8 shows the running state of the mobile object 3 on the road 1,
FIG. 9 geometrically shows the positional relationship between the moving body 3 and the light reflecting means 2R and 2L. The operation of the position measuring device shown in FIG. 7 will be described below with reference to FIGS. 8 and 9. It is now assumed that the traveling direction of the mobile body 3 has already been measured by the direction measuring scanner 4 and the direction measuring device shown in FIG. In this state, the position measuring scanner 7 is being rotated by the motor 77, and therefore the light beam 8 is being rotated and scanned. For example, if this light beam 8 hits the light reflecting means 2L, the light reflecting means 2L will reflect the light in the same direction as the direction of incidence of the light beam, and the reflected light will be directed to the half mirror 74 of the position measuring scanner 7. The light returns, is reflected by this half mirror 74, and enters the light receiver 75. Therefore, the light receiver 75 derives a detection output. The detection output of the photoreceiver 75 is differentiated by the differentiating circuit 22 and applied to the T-type flip-flop 23 as a differentiated pulse. If the Q output of the T-type flip-flop 23 is initially at a low level, the input of the differential pulse causes the Q output to be inverted to a high level. Therefore, AND gate 24 is opened and AND gate 25 is closed. Therefore, the angle data φ _L output from the encoder 76 and waveform-shaped by the waveform shaping circuit 26 is stored in the register 27 through the AND gate 24 . Next, when the position measuring scanner 7 is rotated and displaced to the position shown by the dotted line in FIG. 8, the light beam 8 hits the light reflecting means 2R. Note that since the rotation speed of the position measuring scanner 7 by the motor 77 is quite fast, it is assumed that the moving body 3 hardly moves between the time when the light beam 8 hits the light reflecting means 2L and the time when it hits the light reflecting means 2R. Assume. The light reflecting means 2R reflects the incident light beam 8 in the same direction. Therefore, the half mirror 74 receives and reflects the reflected light from the light reflecting means 2R. The reflected light from the half mirror 74 is sent to the receiver 7
5 receives the light and derives a detection output. Therefore, a differential pulse is output from the differentiating circuit 22, and the output state of the T-type flip-flop 23 is inverted. That is, the Q output becomes low level. In this state, AND gate 24 is closed and AND gate 25 is opened. Therefore,
The angle data φ _R from the encoder 76 passes through the AND gate 25 and is stored in the register 28 .
Next, the calculation circuit 29 calculates the current position of the moving object 3 based on the angle data φ _L and φ _R stored in the registers 27 and 28 and the azimuth information ±θ from the positive/negative discrimination circuit 21 . This calculation is performed as follows.

First, the calculation circuit 29 calculates the angles α _L and α _R shown in FIG. 9 using the following equations (1) and (2). Note that the angle α _L is the angle between the light reflecting means 2R and the current position A of the moving body 3 with the light reflecting means 2L as the apex, and the angle α _R is the angle between the light reflecting means 2R and the moving body 3 moving with the light reflecting means 2R as the apex. This is the angle between the body 3 and the current position A.

α _L = 180゜−β _L −φ _L …(1) α _R = 180゜−β _R −φ _R …(2) However, β _L = 90゜−θ and β _R = 90゜+θ .
When calculating these angles β _L and β _R , whether to add or subtract θ from 90° is determined by the sign discrimination circuit 2.
It is determined by the sign of the orientation information θ given from 1. Once the angles α _L and α _R are calculated, the coordinate position of the current position A of the moving body 3 is calculated. This calculation can be easily determined from the angles α _L and α _R because the coordinate positions of the light reflecting means 2L and 2R are known and set in the calculation circuit 29.

In the embodiment described above, the azimuth measuring scanner 4 and the azimuth measuring device shown in FIG. Or a compass or the like may be used.

In addition, this invention is applicable not only to automobiles, but also to golf carts at golf courses, aircraft moving on taxiways at airports, various transportation vehicles on campus, guidance wagons for automatically guiding blind people, and automatic vacuum cleaners. Of course, it can also be applied to various agricultural equipment, construction equipment, etc. That is, it can be applied to all moving objects that move on a plane. In addition, when applying to a moving object running indoors, the light reflecting means 2R and 2L may be provided on a wall or a ceiling.

Furthermore, the present invention provides light reflecting means 2R and 2L.
It is also possible to provide a plurality of sets at appropriate locations on the route that a moving object passes and apply it to automatically guide the moving object.

[Effects of the Invention] As described above, according to the present invention, the current position of a moving body is measured using the reflection of a light beam, so it is different from the conventional method of measuring the current position using radio waves. It has a simpler structure and is less expensive than that, is not subject to regulations under the Radio Law, and is not affected by radio noise. Also,
According to this invention, there is almost no need to perform maintenance and inspection of the light reflecting means, and the time and labor required for this can be significantly reduced.

[Brief explanation of drawings]

FIG. 1 is an illustrative diagram showing an outline of an embodiment of the present invention. FIG. 2 is a front view showing the internal structure of the direction measuring scanner 4 shown in FIG. FIG. 3 is a front view showing the internal structure of the position measuring scanner 7 shown in FIG. 1. FIG. 4 is a schematic block diagram showing the direction measuring device mounted on the moving body 3. As shown in FIG. 5 and 6 are illustrative diagrams for explaining the direction measuring operation performed by the direction measuring scanner 4 and the direction measuring device shown in FIG. 4. In particular, FIG. Progress status and light reflecting means 2
6 is a diagram showing the positional relationship between R and 2L, and FIG. 6 is a geometric explanatory diagram of FIG. 5. FIG. 7 is a schematic block diagram showing a position measuring device mounted on the moving body 3. As shown in FIG. 8 and 9 are illustrative views for explaining the current position measuring operation performed by the position measuring scanner 7 and the position measuring device shown in FIG. 7. In particular, FIG. The current position of the moving body 3 and the light reflecting means 2R and 2L at
FIG. 9 is a geometric explanatory diagram of FIG. 8. In the figure, 22 is a differential circuit, 23 is a T-type flip-flop, 24 and 25 are AND gates,
26 is a waveform shaping circuit, 27 and 28 are registers, 29 is an arithmetic circuit, 30 is a utilization device, 72 is a light source, 73 is a lens, 74 is a half mirror, 75 is a light receiver, 76 is an encoder, and 77 is a motor.

Claims (1)

[Scope of Claims] 1. A device that measures the current position of a moving body using reflection of light, wherein light incident on predetermined coordinate positions on the right and left sides of a path that the moving body should travel, respectively. first and second light reflecting means for reflecting the light beam in the same direction as the incident direction; azimuth measuring means for measuring the traveling direction of the moving object with respect to a predetermined reference direction; a rotary scanning means for rotationally scanning the rotary scanning means, provided in association with the rotary scanning means, and detecting light emitted from the rotary scanning means and reflected by the first or second light reflecting means; a photodetector for detecting the rotational angle of the rotational scanning device; an angle detection device for detecting the rotational angle of the rotational scanning device; and data for capturing angle data from the angle detection device in response to a detection output of the photodetector. an acquisition means, and a calculation for calculating the current position of the moving body based on the traveling direction measured by the orientation measurement means and the angle data acquired by the data acquisition means. A position measuring device for a moving body, comprising means. 2. The position measuring device for a moving body according to claim 1, wherein the azimuth measuring means measures the azimuth using reflection of light from the light reflecting means. 3. The direction measuring means is provided in association with the light emitting means and the light emitting means for emitting light in the left and right directions perpendicular to the traveling direction of the moving body, and the direction measuring means is provided in association with the light emitting means, and is emitted from the light emitting means to a right side light detector for detecting light reflected by the first light reflecting means; and a right light detector provided in association with the light emitting means, the light being emitted from the light emitting means and reflected by the second light reflecting means. a left-side photodetector for detecting the reflected light; and a left-side photodetector for detecting the reflected light; and the mobile object traveled during a period between when one of the right and left side photodetectors detects the reflected light and when the other detects the reflected light. a mileage measuring means for measuring the distance; based on the mileage measured by the mileage measuring means and preset distance information between the first and second light reflecting means; 2. The position measuring device for a moving body according to claim 2, further comprising: angle calculation means for calculating the traveling direction of the moving body with respect to a predetermined reference direction. 4. The moving object position measuring device according to claim 1, wherein the azimuth measuring means is a gyroscope. 5. The moving object position measuring device according to claim 1, wherein the direction measuring means is a direction magnet.