JPH0680437B2 - Position measuring device for moving body - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position measuring device for a mobile body, and more particularly to a device for measuring the current position of the mobile body by utilizing light reflection.

[Prior Art] Conventionally, as a device for measuring the current position of a moving body such as an automobile or an unmanned mobile carrier in a factory, for example, radio wave transmission sources are installed at a plurality of locations on the ground, and There is a device that receives a radio wave and calculates the current position of the mobile body from the reception direction and the like.

[Problems to be Solved by the Invention] The position measuring device using radio waves as described above requires a plurality of transmitting devices and thus has a problem of being expensive. There is also a problem that frequent inspections and maintenance must be performed in order for the transmitting device to always operate normally. In particular, when used outdoors, the environment in which the transmitter is installed becomes harsh, which increases the frequency of inspection and maintenance. Further, since the position measuring device as described above uses radio waves, there is a problem that it is subject to regulations of the Radio Law and is affected by radio noise.

Therefore, an object of the present invention is to provide a position detecting device for a moving body, which has a simple and inexpensive structure, requires almost no inspection or maintenance, and is not subject to regulation by the Radio Law.

[Means for Solving Problems] In the present invention, the first and second light reflecting means are provided at predetermined coordinate positions on the right side and the left side of the path to be moved by the moving body, and these light beams are transmitted from the moving body. The present invention is configured to measure the current position of the moving body by emitting a light beam toward the reflecting means and detecting the reflected light, and the azimuth measuring means, the first and second light emitting means, and the first and second light emitting means. It is provided with first and second photodetectors, a traveling distance measuring means, and a computing means. The first and second light reflecting means have an optical property of reflecting incident light in the same direction as the incident direction. The azimuth measuring means is for measuring the traveling azimuth of the moving body with respect to a predetermined reference azimuth. The first light emitting means is arranged so as to emit a light beam to the right with respect to the traveling direction of the moving body at a predetermined angle, and the second light emitting means is arranged to the left with respect to the traveling direction of the moving body. It is arranged to emit a light beam at a predetermined angle. A first light detector is provided in association with the first light emitting means and is configured to detect light emitted from the first light emitting means and reflected by the first light reflecting means. It The second photodetector is provided in association with the second light emitting means and is configured to detect light emitted from the second light emitting means and reflected by the second light reflecting means. It The mileage measuring means
The first and second photodetectors are configured to measure the distance traveled by the moving body between the time when one of the first and second photodetectors detects the reflected light and the time when the other detects the reflected light. The computing means determines the current position of the moving body based on the traveling azimuth measured by the azimuth measuring means, the traveling distance measured by the traveling distance measuring means, and the coordinate positions of the first and second light reflecting means. It is configured to operate.

[Operation] In the present invention, since the coordinate positions of the first and second light reflecting means are known in advance, the traveling direction of the moving body with respect to the reference direction and one of the first and second photodetectors are reflected. The distance traveled by the moving body between the time when the light is detected and the time when the other detects the reflected light is measured, and based on these coordinate positions and the two types of measured information, the moving body is moved from a geometrical relationship. The current position of can be calculated.

[Embodiment] FIG. 1 is an illustrative view showing an outline of an embodiment of the present invention. In the figure, light reflecting means 2R and 2L are provided on the right side and the left side of the road 1, respectively. These light reflecting means 2R and 2L have an optical property of reflecting incident light in the same direction as the incident direction, and for example, a corner cube or the like is used. Also, the light reflection means 2R
And 2L are selected so that the line segment α connecting them is orthogonal to the predetermined reference azimuth X. The reference azimuth X may be selected, for example, in parallel with the road 1, or may be selected so as to coincide with north, south, east, or west regardless of the direction in which the road extends.

On the other hand, a moving body 3 such as an automobile is provided with an azimuth measuring scanner 4 for measuring its traveling azimuth Y and a position measuring scanner 7 for measuring its current position. The azimuth measuring scanner 4 emits the light beams 5R and 5L in the right and left directions orthogonal to the traveling azimuth Y of the moving body 3. The position measuring scanner 7 emits a light beam 8R in an angle direction of 45 ° to the right and an optical beam 8L in an angle direction of 45 ° to the left with respect to the traveling direction Y of the moving body 3.

FIG. 2 is a diagram showing an internal structure of the azimuth measuring scanner 4 shown in FIG. 1, and shows a state in which the azimuth measuring scanner 4 is viewed from the front. In the figure, the azimuth 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 the light emitting / receiving units 4L and 4R have the same structure as the left / right symmetrical structure, only the right light emitting / receiving unit 4R will be described here. Inside the lens barrel 41R, the light source 42R and the lens 43R
And the half mirror 44R are stored. As the light source 42R, for example, a laser light source having sharp directivity is used.
The lens 43R turns the light emitted from the light source 42R into a planar light beam 5R that spreads in the vertical direction. The plane beam is used in order to ensure that the light beam 5R hits the light reflecting means 2R even if the moving body 3 vibrates to some extent. Lens 43
The light beam 5R emitted from R passes through the half mirror 44R and is emitted to the outside. In addition, the half mirror 44R is a light reflecting means 2R.
The reflected light 6R from is reflected. The light receiver 45R is provided at a position where the reflected light of 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 the 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 as viewed from above. In the figure, the position measuring scanner 7 includes a pair of left and right light emitting / receiving units 7L and 7R arranged at an opening angle of 90 °. The light emitting / receiving unit 4L is for emitting the light beam 8L in an angle direction of 45 ° to the left with respect to the traveling direction Y of the moving body 3. The light projecting / receiving unit 7R is for emitting the light beam 8R in an angle direction of 45 ° to the right with respect to the traveling direction Y of the moving body 3. Since the light projecting / receiving units 7L and 7R have the same symmetrical structure, only the right light projecting / receiving unit 7R will be described here. Inside the lens barrel 71R, a light source 72R and a lens 73R
And the half mirror 74R are stored. As the light source 72R, for example, a laser light source having a sharp directivity is used.
The lens 73R turns the light emitted from the light source 72R into a planar light beam 8R that spreads in the vertical direction. In FIG. 3, the light beam 8R appears to be linear because the position measuring scanner 7 is viewed from the upper side. The reason why the light beam 8R is such a planar beam is to ensure that the light beam 8R hits the light reflecting means 2R even if the moving body 3 vibrates to some extent. Lens 73
The light beam 8R emitted from R passes through the half mirror 74R and is emitted to the outside. In addition, the half mirror 74R is the light reflection means 2
Reflects the reflected light from R. The light receiver 75R is provided at a position where the reflected light of the half mirror 74R can be detected. This light receiver 75R uses, for example, a photodiode, a phototransistor, or the like, and derives a detection signal in response to receiving the reflected light from the half mirror 74R. As described above, the position measuring scanner 7 shown in FIG. 3 has substantially the same configuration as the azimuth measuring scanner 4 shown in FIG.

FIG. 4 is a schematic block diagram showing an azimuth measuring device mounted on the moving body 3. 5 and 6 are schematic diagrams for explaining the operation of the azimuth measuring apparatus of FIG. Less than,
The configuration and operation of the azimuth measuring apparatus shown in FIG. 4 will be described with reference to FIGS. 5 and 6.

Now, as shown in FIG. 6, it is assumed that the traveling direction Y of the moving body 3 is θ with respect to the reference direction X. In this case, as shown in FIG. 5, first, the light beam 5L from the left light projecting / receiving unit 4L strikes 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, is reflected by the half mirror 44L, and enters the light receiver 45L. In response, the light receiver 45L derives a detection output and supplies the detection output to the first-arrival discrimination circuit 10 and the flip-flop 12 via the OR gate 11. This flip-flop 12
Since the one that derives the set output with the first input and the reset output with the next input is used, is set by the output of the photodetector 45L that first detects the reflected light. The set output (high level) of the flip-flop 12 is supplied to the AND gate 13, activates the AND gate 13, and is inverted to low level and supplied to the AND gate 14.
Disable the AND gate 14. Accordingly, the pulse generated from the pulse generator 15 is given to the counter 16 via the AND gate 13, so that the counter 16 counts the given number of pulses. Here, the pulse generator 15 generates a pulse each time the moving body 3 advances by a predetermined unit distance, and for example, a rotary encoder or the like that detects the rotation of the wheels of the moving body 3 is used. Therefore, by counting the number of output pulses of the pulse generator 15, the traveling distance of the moving body 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 emitting and receiving unit 4R is reflected by the light reflecting means 2R.
Hit Therefore, the reflected light of the light reflecting means 2R returns to the half mirror 44R, is reflected by the half mirror 44R, and enters the light receiver 45R. In response, the light receiver 45R derives a detection output, and supplies the detection output to the first-arrival discrimination circuit 10 and the flip-flop 12 via the OR gate 11. Since the output of the light receiver 45R is the second signal, the flip-flop 12 inverts its output logic state to derive a low level signal from the set output terminal and a high level signal from the reset output terminal. Depending on AND
Gate 13 is disabled and AND gate 14 is activated. Therefore, the counter 16 counts the number of pulses n correlated with the distance 1 traveled by the moving body 3 from the time when the light receiver 45L detects the reflected light until the time when the light receiver 45R detects the reflected light, and the counted value n is applied to one input of the divider circuit 17 via the AND gate 14. Further, the reset output of the flip-flop 12 is given as a reset signal of the counter 16 with a delay of a fixed time determined by the timer 18.

The other input of the division circuit 17 is set to the set value of the interval setting section 19.
nw is given. The interval setting section 19 includes the light reflecting means 2
A value nw that is correlated with the distance d between R and 2L is preset. That is, the interval setting unit 19 is preset with the number of pulses that will be obtained from the pulse generator 15 if the moving body 3 travels the distance d. Therefore, the division circuit 17 divides the count value n of the counter 16 by the set value nw that correlates with the mounting interval of the light reflecting means 2R, 2L (N / nw) to obtain sin θ ′. This angle θ ′ is, as shown in FIG.
The angle formed by the light beams 5L and 5R with respect to the line α connecting 2R and 2L is equal to the angle θ formed by the traveling azimuth Y of the moving body 3 with respect to the reference azimuth X. Therefore, the division circuit 17 si
Calculate nθ. The output of the division circuit 17 is given to the conversion circuit 20, and sin θ is converted into the angle θ. This conversion circuit 20
Is not shown, for example, sin θ (0 ≦ θ <9
(0 °) is included in the ROM in which each antilogarithm (sine value) is set, and the angle θ corresponding to the antilogarithm equal to the division value (n / nw) from the division circuit 17 is read out. . Conversion circuit
The angle θ derived from 20 is an absolute value, and the reference azimuth X
It is not clear whether the angle θ is positive or negative. Therefore, in order to determine whether the angle θ is positive or negative, the conversion circuit
The output of 20 is given to the positive / negative discrimination circuit 21.

The first-arrival discrimination circuit 10 includes a detection output of the photoreceiver 45R and
Which of the 5L detection outputs precedes is discriminated, and the first arrival discrimination output is given to the positive / negative discrimination circuit 21. Positive / negative determination circuit 21
Determines whether the angle θ is positive or negative based on the output of the first-arrival discrimination circuit 10. That is, the positive / negative determination circuit 21 determines that the angle θ is negative (-) when the first arrival determination circuit 10 determines that the detection output of the light receiver 45R precedes, and the first arrival determination that the detection output of the light receiver 45L precedes. When the circuit 10 determines, the angle θ is determined to be positive (+). For example, when the moving body 3 travels as shown in FIG. 5, the photodetector 45L first derives the detection output, so that the first-arrival discrimination circuit 21 discriminates the angle θ as positive (+) and outputs + θ. .

As described above, according to the azimuth measuring device of FIG. 4, the angle θ formed by the traveling azimuth Y of the moving body 3 with respect to the reference azimuth X can be accurately measured.

FIG. 7 is a schematic block diagram showing a position measuring device mounted on the moving body 3. The parts having the same configurations as those of the azimuth measuring device shown in FIG. 4 are designated by the same reference numerals and the description thereof will be omitted. In the figure, receivers 75R and 75L shown in FIG.
The outputs of the two are applied to one input and the other input of the OR gate 11, respectively. Here, the circuit components 11 to 16 and 18 constitute means for measuring the traveling distance of the moving body 3, and the configuration and operation thereof are the same as those shown in FIG. The output of the AND gate 14 is given to the arithmetic circuit 22. Further, the arithmetic circuit 22 is provided with azimuth information (angle θ formed by the traveling azimuth Y of the mobile 3 with respect to the reference azimuth X) from the positive / negative discrimination circuit 21 shown in FIG. Although not shown, the arithmetic circuit 22 is configured to include, for example, a microcomputer and the like, and is for calculating the current position of the moving body.

8 to 11 are diagrams for explaining the operation of the position measuring device of FIG. 7, and in particular, FIG. 8 is a diagram showing a traveling state of the moving body 3 on the road 1, and FIG. FIG. 10 and FIG. 10 are diagrams geometrically showing the positional relationship between the moving body 3 and the light reflecting means 2R and 2L, and FIG. 11 is a flow chart showing the operation of the arithmetic circuit 22. The operation of the position measuring device shown in FIG. 7 will be described below with reference to FIGS. now,
As shown in FIG. 8, when the position measuring scanner 7 reaches the point A, the light beam 8L hits the light reflecting means 2L, and when the position measuring scanner 7 reaches the point B, the light beam 8R hits the light reflecting means 2R.
It is assumed that the In this case, the distance P from the point A to the point B is measured by the OR gate 11, flip-flop 12, AND gates 13 and 14, pulse generator 15, counter 16 and timer 18 shown in FIG. This measurement operation is
Since the operation is the same as that described with reference to FIG. 4, the description thereof will be omitted. Next, the operation of the arithmetic circuit 22 will be described. Arithmetic circuit 22
First, as shown in step S11 of FIG. 11, direction information ± θ is input from the positive / negative determination circuit 21. And step
In S12, the angle γ formed by the light reflecting means 2L and the light reflecting means 2R with the apex of the light reflecting means 2L is calculated by the following equation.

[gamma] = 180 [deg.]-45 [deg.]-[beta] However, [beta] = 90 [deg.]-[theta] Then, in step S13, the coordinates of the point C are calculated based on the positive / negative sign of the direction information ± [theta] and the angle [gamma]. This point C
Is a circle whose diameter is the line segment α connecting the light reflecting means 2R and 2L
22 and the line segment connecting the point A and the light reflecting means 2L.
Since the coordinate positions of the light reflecting means 2R and 2L are known in advance, the equation of the circle 22 is also known in advance. Therefore, if the angle γ is known, the coordinates of the point C can be easily calculated. Next, in step S14, the distance information n from the AND gate 14 is input. This distance information n is the distance traveled by the moving body 3 between the time when one of the light receivers 75R and 75L detects the reflected light and the time when the other detects the reflected light, and is between point A and point B. Is equal to the distance P of. Then, step S1
Proceed to 5 and calculate the distance Q between the point C and the point B. 10th
As shown in the figure, the triangle having the points A, B and C as vertices is an isosceles right triangle, so the distance Q can be easily calculated by the following equation.

Next, in step S16, the coordinates of the point B are calculated based on the coordinates of the point C and the distance Q. The coordinates of the point B are on the line segment connecting the point C and the light reflection means 2R, and are present at the distance from the point C to Q. Then, the process proceeds to step S17, and step S
The coordinates of the point B calculated in 16 are output as position information.

When the moving body 3 passes over the point C at the azimuth angle θ,
Since the light beams 8R and 8L strike the light reflecting means 2R and 2L at the same time, the detection outputs are simultaneously obtained from the light receivers 75R and 75L. Therefore, in this case, the distance P becomes 0, and the distance Q calculated in step S15 also becomes 0. Therefore,
The coordinate position of the point C is calculated as the current position.

Note that the azimuth information and position information obtained as described above can be used in various ways. For example, it may be displayed on a display or may be used as information for automatic piloting. For automatic piloting, a plurality of sets of light reflecting means may be arranged along the road 1 at predetermined intervals.

FIG. 12 is an illustrative view showing the outline of another embodiment of the present invention. In the figure, in this embodiment, the road 1 through which the moving body 3 should pass has two lanes, and light reflecting means 2R and 2L are provided at the right end and the left end of the road having the two lanes. In this case, the position measuring scanner 7 is arranged so as to emit the light beam 8R at an angle of 60 ° to the right and the light beam 8L at an angle of 30 ° to the left with respect to the traveling direction Y of the moving body 3. . In this embodiment, although the geometrical approach for obtaining the current position of the moving body 3 is slightly different from the above-mentioned embodiment,
A person skilled in the art can easily realize the above-described embodiment, and therefore the description thereof will be omitted.

In the embodiment described above, the azimuth measuring scanner 4 is used as means for measuring the traveling azimuth of the moving body 3.
Although the azimuth measuring device shown in FIG. 4 and FIG. 4 are used, a gyroscope, a azimuth magnet, or the like may be used instead of them.

Further, in the above-mentioned embodiment, the position measuring scanner 7 which emits the light beams 8R and 8L having an opening angle of 90 ° is used, but this embodiment is not limited to this, and other opening angles are used. Positioning scanners that emit light beams 8R and 8L may be used. Theoretically, it is possible to measure the current position of the moving body 3 unless the opening angle of the light beams 8R and 8L is 180 °.

Further, according to the above-described embodiment, the position measuring scanner 7 is arranged so as to emit the light beam toward the front of the moving body 3, but the position measuring scanner 7 faces toward the rear of the moving body 3. May be arranged to emit a light beam.

[Effects of the Invention] As described above, according to the present invention, the current position of the moving body is measured by utilizing the reflection of the light beam. Therefore, the conventional method for measuring the current position using radio waves is used. Compared to, the structure is simple and inexpensive, it is not regulated by the Radio Law, and is not affected by radio noise. Further, according to the present invention, there is almost no need to perform maintenance and inspection of the light reflecting means, and the time and labor therefor can be greatly reduced.

[Brief description of drawings]

FIG. 1 is an illustrative view showing the outline of one embodiment of the present invention. FIG. 2 is a diagram showing the internal structure of the azimuth measuring scanner 4 shown in FIG. FIG. 3 is a diagram showing the internal structure of the position measuring scanner 7 shown in FIG. FIG. 4 is a schematic block diagram showing an azimuth measuring device mounted on the moving body 3. 5 and 6 are schematic diagrams for explaining the azimuth measuring operation performed by the azimuth measuring scanner 4 and the azimuth measuring device shown in FIG. 4, and in particular, FIG. FIG. 6 is a diagram showing a positional relationship between the light reflection means 2R and 2L, and FIG. 6 is a geometrical explanatory diagram of FIG. FIG. 7 is a schematic block diagram showing a position measuring device mounted on the moving body 3. 8 to 10 are schematic views for explaining the current position measuring operation performed by the position measuring scanner 7 and the position measuring device shown in FIG. 7, and in particular, FIG. State and light reflection means 2R
And FIG. 9 is a diagram showing a positional relationship with 2L, and FIG.
FIG. 10 is a view showing the geometrical relationship of the figure, and FIG. 10 is an enlarged view around points A, B and C in FIG. 9. FIG. 11 is a flow chart for explaining the operation of the arithmetic circuit 22 shown in FIG. FIG. 12 is an illustrative view showing the outline of another embodiment of the present invention. In the figure, 1 is a road, 2R and 2L are light reflecting means, 3 is a moving body, 4 is a direction measurement scanner, 7 is a position measurement scanner, 72R and 72L are light sources, 75R and 75L are light receivers, 15
Is a pulse generator, 16 is a counter, and 22 is an arithmetic circuit.

Claims (7)

[Claims] 1. An apparatus for measuring a current position of a moving body by utilizing light reflection, wherein the incident light is made incident on predetermined coordinate positions on the right side and the left side of a path to be moved by the moving body. First and second light reflecting means for reflecting in the same direction as the direction, and azimuth measuring means for measuring a traveling direction of the moving body with respect to a predetermined reference direction; First light emitting means for emitting a light beam to the right at a predetermined angle, second light emitting means for emitting a light beam to the left at a predetermined angle to the traveling direction of the moving body, A first photodetector for detecting light emitted from the first light emitting unit and reflected by the first light reflecting unit, the second photodetector being provided in association with the first light emitting unit; The second light emitting means provided in association with the light emitting means of A second photodetector for detecting the light emitted from the step and reflected by the second light reflecting means, after one of the first and second photodetectors detects the reflected light The traveling distance measuring means for measuring the distance traveled by the moving body until the other detects the reflected light, and the traveling azimuth measured by the azimuth measuring means, and the traveling distance measuring means. Based on the traveled distance and the coordinate positions of the first and second light reflecting means,
A moving body measuring apparatus, comprising: computing means for computing the current position of the moving body at the time when the other of the first and second photodetectors detects the reflected light. 2. The first and second light emitting means are arranged so as to emit light beams at symmetrical angles to the right and left with respect to the traveling direction of the moving body, respectively. The position measuring device for a moving body according to claim 1. 3. The first light emitting means is arranged so as to emit a light beam at an angle of 45 ° to the right with respect to the traveling direction of the moving body, and the second light emitting means comprises: 3. The position measuring device for a moving body according to claim 2, which is arranged so as to emit a light beam at an angle of 45 [deg.] To the left with respect to the traveling direction of the moving body. 4. The first and second light emitting means are arranged so as to emit a light beam at an asymmetric angle to the right and left with respect to the traveling direction of the moving body, respectively. The position measuring device for a moving body according to claim 1. 5. The azimuth measuring means is provided in association with a third light emitting means for emitting light in a lateral direction orthogonal to a traveling direction of the moving body, and the third light emitting means. A third light detector for detecting light emitted from the third light emitting means and reflected by the first light reflecting means; and a third light detector provided in association with the third light emitting means. A fourth light detector for detecting light emitted from the third light emitting means and reflected by the second light reflecting means; and one of the third and fourth light detectors. By the azimuth measuring mileage measuring means for measuring the distance traveled by the moving body from the time when the reflected light is detected until the other detects the reflected light, the azimuth measuring mileage measuring means Measured distance traveled and the preset first and second light reflectors The angle calculation means which calculates the advancing azimuth | direction of the said moving body with respect to the predetermined reference | standard azimuth | direction based on the distance information between the distances, The claim 1 in any one of Claim 1 thru | or 4. Position measuring device for moving objects. 6. The position measuring device for a moving body according to claim 1, wherein the azimuth measuring means is a gyroscope. 7. The position measuring device for a moving body according to any one of claims 1 to 4, wherein the azimuth measuring means is an azimuth magnet.