JPH0476409B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a device for measuring the traveling direction of a moving object, and particularly when a moving object such as an automobile or an airplane moves along a desired route, the direction of movement of a moving object is determined in advance. The present invention relates to a device that measures the (deviation angle) of the moving direction of a moving object with respect to a reference direction (for example, north, south, east, west, and the like).

[Prior Art] For example, when guiding an aircraft from the runway to the taxiway at an airport, or driving a golf cart or car along a predetermined course, if the direction of movement of these moving objects can be measured, automatic It will be very convenient to use this system as it will allow guidance etc.

Therefore, the applicant of the present application proposed a device for measuring the traveling direction of a moving object as described above in Japanese Patent Application No. 13815-1983 (Japanese Patent Application Laid-Open No. 107098-1982). This proposed invention will be briefly explained below. In other words, multiple signal lines (paint, tape, etc.) are installed on the moving object to detect the position of the moving object along a predetermined direction related to the moving object's course. First detection means and second detection means for detecting the signal line are provided on the right and left sides of the moving body. The first detection means detects the signal line and the second detection means detects the signal line, or after the second detection means detects the signal line and the first detection means detects the signal line. measures the distance traveled by the moving object until it detects the signal line, and determines the reference direction based on this measurement result and the distance (known in advance) between the first and second detection means. The deflection angle in the moving direction of the moving object relative to the moving object is calculated.

According to the invention proposed by the applicant as described above,
The deflection angle in the moving direction of the moving body relative to a predetermined reference direction can be measured extremely accurately. In addition, as signal lines, it is sufficient to simply install multiple lines that can be identified in a certain direction, and there is no need to add signals to each signal line to identify each signal line, so the installation cost is low. It's over.

[Problems to be Solved by the Invention] By the way, in the invention proposed by the applicant as described above, it is difficult to install signal lines when the road surface is in poor condition (for example, it is covered with snow or has severe ups and downs). There was a problem. Furthermore, even if signal lines were installed, there was a problem in that the detection sensitivity of the signal lines would be significantly reduced if the road surface was in poor condition.
Furthermore, since the signal lines are installed on the road surface, they are constantly stepped on by moving objects, and there is a problem in that the signal lines must be inspected from time to time to make sure they are not missing or broken.

Therefore, an object of the present invention is to provide a moving direction measuring device for a moving object that can be easily operated even when the road surface is in poor condition, has no decrease in detection sensitivity, and requires almost no maintenance. .

[Means for Solving the Problems] According to the present invention, first light reflecting means and second light reflecting means are provided on the right side and the left side of the path along which the moving body should travel, respectively. These first and second light reflecting means have optical properties such that they reflect incident light in the same direction. On the other hand, the movable body is provided with a light projecting means for projecting light in left and right directions in the traveling direction of the movable body, and first and second photodetectors in association with the light projecting means. The first photodetector is for receiving light projected from the light projecting means and reflected by the first light reflecting means.
The second photodetector is illuminated by the light emitted from the light projecting means.
This is for receiving the light reflected by the light reflecting means. Then, the distance traveled by the moving object is measured between when one of the first and second photodetectors detects the reflected light and when the other of the first and second photodetectors detects the reflected light. However, based on this measurement result and the distance between the first and second light reflecting means, the deflection angle in the moving direction of the moving object with respect to a predetermined reference direction is calculated.

[Operation] In this invention, since the distance between the first and second light reflecting means is known in advance, one of the first and second light detectors detects the reflected light, and then the other one detects the reflected light. If the distance traveled by the moving object before detecting the light is measured, based on this measurement result and the distance between the first and second light reflecting means,
The deviation angle of the traveling direction of the moving pair with respect to the reference direction can be determined by calculation.

[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 are
It has an optical property of reflecting incident light in the same direction as the incident direction, and for example, a corner cube is used. In addition, the light reflecting means 2
R and 2L are selected such that the line segment α connecting them is orthogonal to a predetermined reference direction X. This reference direction X may be selected, for example, parallel to the road 1, or may be selected, for example, north, south, east, west, etc., regardless of the direction in which the road extends. On the other hand, a light emitting/receiving device 4 is provided in a moving body 3 such as an automobile. This light projecting/receiving device 4 projects light beams 5R and 5L in right and left directions perpendicular to the traveling direction of the moving body 3.

FIG. 2 is a diagram showing the internal structure of the light emitting/receiving device 4 shown in FIG. 1. In the figure, this light emitting/receiving device 4
includes a pair of left and right light emitting/receiving units 4L and 4R. The light projecting/receiving unit 4L is for projecting light to the left side of the moving body 3, and the light projecting/receiving unit 4R is for projecting light to the right side of the moving body 3. Since these light emitting/receiving units 4L and 4R are laterally symmetrical and have the same structure, only the right light emitting/receiving unit 4R will be described here. Inside the lens barrel 41R, a light source 42R,
A lens 43R and a half mirror 44R are housed. As the light source 42R, a laser light source or the like with sharp directivity is used. The lens 43R is for converting the light emitted from the light source 43R into a planar light beam 5R that spreads in the vertical direction. The reason why the light beam 5R is made into 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 is transmitted through a half mirror 44R and projected 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 it can receive the reflected light from the half mirror 44R. 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 block diagram showing the electric circuit portion of one embodiment of the present invention. FIG. 4 is an illustrative diagram to help understand the heading measuring operation, which is a feature of the present invention. Further, FIG. 5 is a diagram geometrically showing the positional relationship shown in FIG. 4. Below, the first
The specific configuration and operation of the circuit shown in FIG. 3 will be described with reference to FIGS.

In the following explanation, as shown in FIGS. 4 and 5, the reference direction is assumed to be X, and the moving body 3 is
Assume that the vehicle travels in a direction Y at an angle θ from .
In this case, first the left emitter/receiver unit 4L
The light beam 5L from 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 6L returns to the half mirror 44L, is reflected by this 44L, and enters the light receiver 45L. Accordingly, the light receiver 45 derives a detection output, provides the detection output to the first-come-first-served discrimination circuit 10, and also outputs the detection output to the OR gate 11.
is applied to flip-flop 12 via. Since this flip-flop 12 derives a set output from the first input and a reset output from the next input, it is set by the output of the light receiver 45L which first detects the reflected light. The set output (high level) of flip-flop 12 is AND
is applied to the gate 13, activates the AND gate 13, and is inverted to low level.
applied to AND gate 14, said AND gate 14
to immobilize. 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.

Assuming that the moving body 3 travels a little and comes to the position indicated by the dotted line in FIG. It is also applied to the flip-flop 12 via the 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 enabled. Therefore, the counter 16 counts the number of pulses n that correlates to the distance l traveled by the moving body 3 from the time when the light receiver 45L detects the reflected light 6L until the time when the light receiver 45R detects the reflected light 6R. , the counted value n is applied to one input of the division circuit 17 via the AND gate 14. Further, the reset output of the flip-flop 12 is given as a reset signal to the counter 16 after a certain period of time determined by the timer 18.

The other input of the division circuit 17 is given the setting value nw of the interval setting section 19. This interval setting section 19 has a pulse generator 15 that determines the distance d between the light reflecting means 2R and 2L if the moving object 3 is running.
The value nw that correlates to the number of pulses that would be obtained from
is set in advance. Therefore, the division circuit 17 divides the count value n of the counter 16 by a set value nw that correlates to the mounting interval of the light reflecting means (n/nw), and calculates the moving object for the line segment α connecting the light reflecting means 2R and 2L. 3
Find sin θ' when the angle θ' in the left-right direction is θ'.
Since this sin θ′ is equal to the angle θ of the moving direction Y of the moving body 3 with respect to the reference direction X, the division value (n/nw) calculated by the division circuit 17, that is, sin θ, is provided to the conversion circuit 20. This conversion circuit 20 has sinθ
In order to convert the angle θ into an angle θ, for example, set the antilog number (sine value) of sinθ (0≦θ<90°) at each address in the ROM, and then set the antilog number equal to the division value (n/nw). Read out the angle θ of sin θ corresponding to . At this time, the angle θ derived from the conversion circuit 20 is the absolute value of the deflection angle of the traveling direction Y of the moving body 3 with respect to the reference azimuth X, and it is not clear whether the angle θ is positive or negative with respect to the reference azimuth X. Therefore, for the purpose of determining whether the angle θ is positive or negative, the output of the conversion circuit 20 is given to the positive/negative determining circuit 21.

The first-arrival discrimination circuit 10 receives the detection output of the light receiver 45R and the detection output of the light receiver 45L, determines which one arrived first, and provides the first-arrival discrimination output to the positive/negative discrimination circuit 21. The positive/negative discrimination circuit 21 is for discriminating whether the angle θ of the traveling direction Y with respect to the reference azimuth X is positive or negative based on the first-arrival discrimination output. Negative (-) when light 6R is detected
When the light receiver 45L provided on the left side first detects the reflected light 6L, it is determined to be positive (+).
Therefore, when the moving body 3 travels as shown in FIG. Let the given angle θ be +θ.

As described above, according to this embodiment, the distance traveled by the moving body 3 from when one of the photodetectors 45R and 45L detects the reflected light from the light reflecting means 2R and 2L until the other one detects the reflected light from the light reflecting means 2R and 2L. and light reflecting means 2
The traveling direction of the moving body 3 can be accurately measured based on the mounting intervals of R and 2L. Further, the light reflecting means 2R and 2L can be easily installed even if the road surface condition of the road 1 is poor, and the detection sensitivity will not be reduced. Furthermore, since there is almost no need for maintenance, the effort for maintenance and inspection can be significantly reduced.

In addition, in the above-mentioned embodiment, the reference direction
was selected parallel to the extending direction of
may be selected, for example, north, south, east, or west, regardless of the direction in which the road 1 extends. In this case, the light reflecting means 2R, 2L may be installed so that the line segment α connecting the light reflecting means 2R, 2L is orthogonal to the reference direction X. Alternatively, the light reflecting means 2R, 2L may be installed so that the line segment α is perpendicular to the direction in which the road 1 extends, as shown in FIG. You can also do this.

Further, in the above embodiment, the light sources 42R, 42L
I decided to use something with sharp directivity, but
Of course, the present invention can also be realized using a light source with poor directivity, such as a xenon lamp, an infrared lamp, or a semiconductor laser. For example, as shown in FIG. 6, a slit 46 is provided to give directionality to the reflected light from the light reflecting means, and the reflected light transmitted through the slit 46 is reflected by a half mirror 44 to a light receiver 45. Just let it guide you. In this case, the slit 46 has a shape similar to a so-called lapper tube that spreads in the vertical direction in a fan shape. Also,
The light emitted from the light source 420 may be projected to the outside without being converged by a lens. However, it is assumed that light from the light source 420 is shielded from entering the light receiver 45.

Furthermore, in the above embodiment, a pulse generator that generates pulses according to the rotation of the wheels is used to detect the traveling distance of the moving object 3, but the moving distance can be detected by using other methods. It is also possible to detect the mileage of 3. For example, ultrasonic oscillators, electromagnetic wave generators, or off-seat line generators that project ultrasonic waves, electromagnetic waves, or light onto a moving plane are installed on the left and right sides of a moving object, and the reflected signals are detected, and the moving speed is determined by the Doppler effect. Furthermore, the moving distance per unit time may be calculated and measured during movement, and the moving distance per unit time of the moving body may be calculated using half the sum and the difference of the left and right detection outputs.

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. In other words, it can be applied to all moving objects that move on a plane. Note that when the present invention is applied to a moving object that runs indoors, the light reflecting means 2R and 2L may be provided on a wall or a ceiling.

Furthermore, this invention provides light reflecting means 2R, 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 moving direction of a moving body can be accurately measured with a relatively simple configuration and low cost. Further, even if the road surface of the path on which the moving object is to travel is poor, the light reflecting means can be easily installed, and the detection sensitivity of reflected light does not decrease. Furthermore, there is almost no need for maintenance, and the labor for maintenance and inspection can be greatly reduced.

[Brief explanation of the drawing]

FIG. 1 is an illustrative diagram showing an outline of an embodiment of the present invention. FIG. 2 is a diagram showing the internal structure of the light emitting/receiving device 4 shown in FIG. 1. FIG. 3 is a schematic block diagram showing the electric circuit portion of one embodiment of the present invention. FIG. 4 is an illustrative diagram to help understand the heading measuring operation, which is a feature of the present invention. FIG. 5 is a diagram geometrically showing the various positional relationships shown in FIG. 4. FIG. 6 is a diagram showing another example of the light emitting/receiving unit. In the figure, 1 is a road, 2R and 2L are light reflecting means, 3 is a moving body, 4 is a light emitting and receiving device, 4R and 4L are light emitting and receiving units, 41R and 41L are lens barrels, 42R and 42L are light sources, 43R and 43L 44R and 44L are half mirrors, 45R and 45L are light receivers, 10 is a first-come-first-served discrimination circuit, 15 is a pulse generator, 16 is a counter, 17 is a division circuit, 19 is an interval setting section, 20 is a conversion circuit, 21 indicates a positive/negative discrimination circuit.

Claims (1)

[Scope of Claims] 1. A moving direction measuring device for measuring the deflection angle of the moving direction of the moving object with respect to a predetermined reference direction, which comprises: on the right side of the path along which the moving object should travel; , a first light reflecting means that reflects the incident light in the same direction as the incident direction, and a second light reflecting means that reflects the incident light in the same direction as the incident direction is provided on the left side of the path that the moving object should move. A light reflecting means is provided, a light projecting means provided in the moving body and projecting light in left and right directions with respect to the traveling direction of the moving body, and a light projecting means provided in association with the light projecting means. a first photodetector for receiving the light reflected by the first light reflecting means projected from the light projecting means; a second photodetector for receiving the light reflected by the light reflecting means; after one of the first and second photodetectors detects the reflected light, the first and second light detectors detect the reflected light; a traveling distance measuring means for measuring the distance traveled by the moving body until the other one of the detectors detects the reflected light; and a traveling distance measured by the traveling distance measuring means, A moving direction measuring device for a moving object, comprising an angle calculating means for calculating a deviation angle of the moving direction of the moving object with respect to a predetermined reference direction based on the distance between the first and second light reflecting means. 2. The distance measuring means operates according to the movement of the moving object and generates a pulse every time the moving object moves a predetermined unit distance; and the first and second light detection means. one of the first and second photodetectors starts counting the output pulses of the pulse generating means in response to detecting the reflected light, and the other of the first and second photodetectors responds to detecting the reflected light. and a counting means that finishes counting the output pulses of the pulse generating means, and the angle calculating means calculates a count value of the output of the counting means, the first light reflecting means, and the second light reflecting means. Based on the numerical value corresponding to the distance between
2. The moving direction measuring device of claim 1, wherein the device calculates a deviation angle of the moving direction of the moving object with respect to a predetermined reference direction. 3. The pulse generating means according to claim 2, wherein the pulse generating means is provided in connection with the movement of the moving body and is configured to generate a pulse in accordance with the movement of the moving body. A moving direction measuring device. 4. The angle calculating means further includes first-come-first-served discriminating means for discriminating between the output of the first photodetector and the output of the second photodetector, and determining the sign of the deflection angle based on the output of the first-come-first-served discriminating means. A moving direction measuring device for a moving body according to any one of claims 1 to 3, comprising determining means.