JP2001004746A - Collision-preventing device for vehicle running on rail - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a collision-preventing device for achieving more accurate collision prevention in a vehicle-driving system where a plurality of mobile units running on a straight rail. SOLUTION: A laser beam from a laser oscillator 6 passes through a light transmission lens 7, is spread only in a horizontal direction by a cylindrical lens 8a, and becomes a fan beam 30 and is applied to the front. The fan beam 30 is reflected by a recursive reflector 12. The light reception visual field of a laser rangefinder 3 is in a fan by the cylindrical lens 8b. Therefore, the reflection light enters the cylindrical lens 8b and is condensed by a light reception lens 9 and then is converted to an electrical signal by a light detection part 10. A control processing part 11 calculates the distance to a mobile unit 2 according to the time difference between time when the light detection part 10 outputs a significant electrical signal and time when the laser oscillator 6 emits a laser beam.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for preventing collision of a plurality of moving bodies running on a straight rail laid in advance, and in particular, a displacement between a rail and wheels of the moving body. The present invention relates to a rail traveling vehicle collision prevention device capable of taking reliable collision prevention measures even when the horizontal positional relationship of a moving body with respect to a rail is displaced due to the like.

[0002]

2. Description of the Related Art In an industrial system, a vehicle traveling system in which a plurality of vehicles travel on a straight rail is used. For example, there is a system in which a linear rail extending several hundred meters is laid between factory premises or the like, and a plurality of transport vehicles travel on the rail. In such a system, each vehicle is generally operated unmanned. In an unmanned driving system, a general collision avoidance method in which a driver avoids a collision by looking ahead can not be adopted, so a technology for automatically avoiding a collision with a vehicle traveling ahead is important.

In a conventional collision avoidance method in a system running on a straight rail, as shown in FIG.
A laser distance meter 31 that emits a narrow beam is provided at the front of the moving bodies 1 and 2 that run on 1. In FIG. 7, the moving bodies 1 and 2 move from left to right. Further, the laser distance meter 31 is shown only in the moving body 1.

In a system in which a transport vehicle travels,
Unlike railways intended to transport passengers, vehicle stability during travel is not required. As a result, the horizontal positional relationship of the moving bodies 1 and 2 with respect to the rails 41 can be shifted due to a positional shift between the rail 41 and the wheels of the moving bodies 1 and 2, as compared with a railway or the like for transporting passengers. Great nature. Then, as shown in FIG. 7, even when the moving body 2 exists in front of the moving body 1, the laser light 13 emitted from the laser distance meter 31 of the moving body 1 is retroreflected from the moving body 2. There is a possibility that the moving body 1 may not be able to detect the moving body 2 located in front because the body 12 has been removed.

Although an extreme example is shown in FIG. 7, even if the laser beam 13 hits the rear part of the moving body 2, if the position shift occurs, the reflected light will be reflected by the laser range finder. Since it is not reflected in the direction of 31, the laser distance meter 3
I do not return to 1. In other words, even when the degree of the displacement is relatively small, the laser distance meter 31 cannot measure the distance to the moving body 2 ahead.

[0006]

If the laser range finder 31 scans a wide area by oscillating the emission direction of the laser light 13, there is a possibility that the distance measurement becomes impossible due to the horizontal displacement of the moving bodies 1 and 2 with respect to the rail 41. Can be reduced. However, such a configuration complicates the configuration of the apparatus and increases the cost. For example, a motor for rotating the laser device and a motor for rotating the scanning mirror are required, which results in an increase in the size of the device, resulting in a shorter life and a higher price.

As a collision preventing device for a general vehicle running on a road, there is a device for increasing the spread angle of a light transmitting beam as described in Japanese Utility Model Laid-Open No. 4-124406. However, it is specified in that publication that a detection error occurs if the angle of the light transmission beam is simply widened, and the angle must be within a predetermined range. Japanese Patent Application Laid-Open No. 4-283885 also discloses that simply widening the light transmission beam angle is not enough to prevent collision, and the detection angle is changed by a light receiving means for receiving reflected light. Techniques are disclosed.

[0008] However, those techniques relate to a collision prevention device applied to a vehicle traveling on a relatively wide (wide) road such as a road. It cannot be applied immediately to a moving object traveling on. This is because the manner in which the problem occurs differs between a case where the travel path is limited and a case where the travel path is wide such as a road. For example, in a vehicle traveling on a wide traveling road such as a road, the positional relationship between the host vehicle and the preceding vehicle generally varies. Then, the positional relationship of the moving body in the horizontal direction with respect to the traveling path is naturally caused without any problem.

SUMMARY OF THE INVENTION The present invention solves a problem that occurs in a vehicle traveling system in which a plurality of moving bodies travel on a straight rail, and realizes a more accurate collision prevention apparatus. The purpose is to provide.

[0010]

A collision preventing apparatus according to the present invention is mounted on a plurality of moving bodies running on a straight rail laid in advance and prevents a collision of the moving bodies with a collision preventing apparatus for a rail traveling vehicle. Beam emitting means for emitting a fan-shaped fan beam in the horizontal direction, light-receiving means for receiving the reflected light from the forward moving body having a fan-shaped light-receiving field of view, and detecting the time when the fan beam is emitted and the reflected light. It is characterized by comprising measuring means for measuring the distance to the forward moving body based on the time difference from the time of incidence, and braking means for performing braking control based on the measured value of the measuring means.

The beam emitting means includes, for example, a cylindrical lens, and the light receiving means includes, for example, a cylindrical lens.

[0012] The anti-collision device may be realized as including a retroreflector provided at the rear of the moving body. In this case, it is preferable that the retroreflector is installed with the vertical direction (the direction orthogonal to the fan-shaped fan beam in the horizontal direction) as the longitudinal direction.

According to another aspect of the present invention, there is provided a collision prevention device comprising:
Light receiving means for receiving reflected light from the forward moving body and outputting an electric signal corresponding to the incident position, measuring means for measuring a distance to the forward moving body based on the electric signal from the light receiving means, and measuring means And a braking means for performing a braking control based on the measured value.

The light receiving means is, for example, a position sensor for outputting a photocurrent including information corresponding to the incident position. Further, the collision prevention device may be realized as including a retroreflector provided at a rear portion of the moving body with a horizontal direction as a longitudinal direction.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory diagram for explaining a first embodiment of a collision prevention device according to the present invention.
As shown in FIG. 1, a moving body 1 traveling on a rail 41
A laser rangefinder 3 for emitting a fan beam (fan-shaped beam) to measure a distance to a forward moving body is provided at a front portion of the laser beam 2. In addition, a retroreflector 12 is provided at the rear of the moving bodies 1 and 2. In FIG. 1,
The laser range finder 3 is shown only at the mobile 1, and the retroreflector 12 is shown only at the mobile 2.

FIG. 2 is a block diagram showing one configuration example of the collision prevention device. In the configuration illustrated in FIG. 2, the collision prevention device includes a laser distance meter 3, a moving object braking processing unit 4 that performs braking on the moving object 1 based on a measurement result of the laser distance meter 3,
And a power supply unit 5. The laser distance meter 3 includes a laser oscillator 6 for generating laser light, a light transmitting lens 7 for guiding the laser light to the outside, a cylindrical lens (cylindrical lens) 8a for spreading the laser light in a fan shape in the horizontal direction, and a fan-shaped light receiving field. Lens 8b for receiving light, a light receiving lens 9 for condensing light reflected from the retroreflector 12, a light detecting unit 10 for converting the condensed laser light into electricity, and reflecting after emitting the laser light A control processing unit 11 is provided for measuring a distance from a time during which light is received.

Next, the operation will be described. In the laser distance meter 3, the control processing unit 11 causes the laser oscillator 6 to emit, for example, a pulsed laser beam. The laser light from the laser oscillator 6 passes through the light transmitting lens 7 and is expanded only in the horizontal direction by the cylindrical lens 8a, and is radiated forward as a fan beam 30.

When the moving body 2 is present ahead, the fan beam 30 is reflected by the retroreflector 12. The retroreflector 12 is formed of, for example, an acrylic resin, and reflects incident light in substantially the same direction as the incident direction (opposite direction).
Therefore, the reflected light returns to the laser distance meter 3. As shown in FIG. 3, the light receiving field has a fan shape due to the cylindrical lens 8b. Therefore, the reflected light enters the cylindrical lens 8 b and is collected by the light receiving lens 9. Then, the light is converted into an electric signal by the light detection unit 10. As shown in FIG. 3, it is desirable to use, as the cylindrical lens 8a and the cylindrical lens 8b, a lens having a wider light receiving field of view than the fan beam 30, which is an irradiation beam.

The control processing unit 11 calculates the distance to the mobile unit 2 from the time difference between the time when the light detection unit 10 outputs a significant electric signal and the time when the laser oscillator 6 emits laser light. When detecting that the distance calculated by the control processing unit 11 is equal to or less than a predetermined distance, the moving body braking processing unit 4 brakes the moving body 1.

As described above, in this embodiment, the emitted laser light is expanded only in the horizontal direction by the cylindrical lens 8a, the retroreflector 12 returns the incident light to the incident direction, and the light-receiving cylindrical lens 8b is Since the reflected light is incident from the fan-shaped light receiving field of view, in a vehicle traveling system in which a plurality of moving bodies 1 and 2 run on a straight rail 41, the horizontal positional relationship of the moving bodies 1 and 2 with respect to the rails 41 is different. Even if it is shifted, the irradiation laser light
The retroreflector 12 installed at the rear of the moving body is not removed.
Further, the laser range finder 3 has a fan-shaped light receiving field of view, so that it can reliably receive reflected light. Therefore, the rail 41
Even if the positional relationship between the moving bodies 1 and 2 in the horizontal direction is shifted, reliable braking control can be performed.

Further, in this embodiment, since the irradiation laser light has a fan shape, the light quantity decreases at the reflection position. However, since the retroreflector 12 returns the incident light to the incident direction without diffusely reflecting it, Even when the light quantity is low, the laser distance meter 3 can reliably receive the reflected light. That is, the distance measurement can be performed sufficiently with a small amount of light, and the distance measurement distance can be extended. In addition, a general vehicle running on a general road is provided with a retroreflector 12.
It cannot be expected that such a thing is installed. The embodiments described above can be applied to an industrial system or the like to which the present invention is applied, but it is difficult to apply them to a general vehicle running on a general road.

In the above embodiment, the cylindrical lens 8a is used. However, a waveform lens 8c having a shape in which a plurality of cylindrical lenses are arranged as shown in FIG. The same operation and effect as those of the above embodiment can be obtained. In the waveform lens 8c, each cylindrical lens portion spreads the beam only in the horizontal direction, so that the irradiation beam also has a fan shape.

Further, if a laser rangefinder 3 is added to the rear of the moving bodies 1 and 2 and a retroreflector 12 is added to the front,
It is also possible to calculate the distance to the moving body located behind. In this case, collision can be avoided even when the moving bodies 1 and 2 move backward.

FIG. 5 is a block diagram showing a second embodiment of the present invention. In this case, the light emitted from the laser oscillator 6 of the laser range finder 3A is directly irradiated forward from the light transmitting lens 7. Then, the reflected light from the retroreflector 12 installed on the moving body 2 enters the position sensor 13 through the light receiving lens 9. In FIG. 5, the light transmitting lens 7 and the light receiving lens 9 are shown as being relatively separated from each other. , Light receiving lens 9
Is installed near the light transmitting lens 7.

In this embodiment, even if the positional relationship between the moving bodies 1 and 2 in the horizontal direction with respect to the rail 41 is deviated, the reflected light enters the laser distance meter 3A as shown in FIG. As shown in B), the retroreflector 12 is preferably installed horizontally.

FIG. 6 is an explanatory diagram showing the position sensor 13 used in this embodiment. The position sensor 13 has, for example, a three-layer structure of a P layer, an I layer, and an N layer in the upper, middle, and lower layers. The incident light is photoelectrically converted and provided as photocurrents I1 and I2 in, for example, the P layer. Are output separately from the two electrodes. The difference or ratio between the photocurrents I1 and I2 differs depending on the incident position of the incident light. That is, the incident position can be known from the difference or ratio between the photocurrents I1 and I2.

As shown in FIG. 5A, the incident position of the incident light on the position sensor 13 corresponds to the distance from the moving body 2 ahead. Therefore, the control processing unit 11 that inputs the photocurrents I1 and I2, which are the outputs of the position sensor 13, can calculate the distance to the moving body 2 from the difference or ratio between the two inputs. When detecting that the distance calculated by the control processing unit 11 is equal to or less than a predetermined distance, the moving body braking processing unit 4 brakes the moving body 1.

In this embodiment, since the inexpensive position sensor 13 can be used, a collision prevention device can be realized at a lower cost than in the first embodiment. In addition, by installing the retroreflective body 12 horizontally behind the moving bodies 1 and 2,
For example, the laser distance meter 3A of the moving object 1 can measure the distance between the moving object 2 and the moving object 2 even if the horizontal positional relationship of the moving object 2 is shifted.

[0029]

As described above, according to the present invention, a collision preventing device for preventing a collision of a moving body running on a straight rail laid in advance is provided by a beam for emitting a fan-shaped fan beam in a horizontal direction. Emission means, light-receiving means for receiving reflected light from the forward moving body having a fan-shaped light-receiving field of view, and distance to the forward moving body based on a time difference between the time when the fan beam is emitted and the time when the reflected light is incident. And a braking means for performing braking control based on the measurement value of the measuring means, there is an effect that more accurate collision prevention can be realized.

Further, the collision preventing device includes a light receiving means for receiving reflected light from the forward moving body and outputting an electric signal corresponding to the incident position, and a light receiving means for detecting the collision with the forward moving body based on the electric signal from the light receiving means. In the case where a configuration including the measuring means for measuring the distance and the braking means for performing the braking control based on the measurement value of the measuring means is provided, the effect of being able to realize a more accurate and more accurate collision prevention at a lower cost is obtained. is there.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram for describing a first embodiment of a collision prevention device according to the present invention.

FIG. 2 is a block diagram illustrating a configuration example of a collision prevention device.

FIG. 3 is an explanatory diagram for explaining a fan beam and a light receiving field;

FIG. 4 is an explanatory diagram for explaining an operation of a waveform lens.

FIG. 5 is a block diagram showing a second embodiment of the present invention.

FIG. 6 is an explanatory diagram showing a position sensor.

FIG. 7 is an explanatory diagram showing a collision avoidance method in a conventional system traveling on a straight rail.

[Explanation of symbols]

 Reference numerals 1 and 2 Moving body 3 Laser distance meter 4 Moving body braking control unit 5 Power supply unit 6 Laser oscillator 7 Light transmission lens 8a Cylindrical lens 8b Cylindrical lens 9 Light receiving lens 10 Light detection unit 11 Control processing unit 12 Recursive reflector 30 Fan beam 41 rail

Claims (7)

[Claims] An anti-collision device for a rail traveling vehicle mounted on a plurality of moving bodies running on straight rails laid in advance and preventing collision of the moving bodies, comprising a fan-shaped fan beam in a horizontal direction. A beam emitting means for emitting light, a light receiving means having a fan-shaped field of view for receiving reflected light from a forward moving body, and a forward moving body based on a time difference between a time when a fan beam is emitted and a time when reflected light is incident. A collision preventing device for a rail traveling vehicle, comprising: a measuring unit that measures a distance to the vehicle; and a braking unit that performs braking control based on a measurement value of the measuring unit. 2. The rail traveling vehicle collision prevention device according to claim 1, wherein the beam emitting means includes a cylindrical lens, and the light receiving means includes a cylindrical lens. 3. The collision preventing device for a rail traveling vehicle according to claim 2, further comprising a retroreflector provided at a rear portion of the moving body. 4. The collision preventing device for a rail traveling vehicle according to claim 3, wherein the retroreflector is installed with a vertical direction as a longitudinal direction. 5. A collision preventing device for a rail traveling vehicle mounted on a plurality of moving bodies running on a straight rail laid in advance and preventing a collision of the moving bodies, wherein the beam emitting means emits a light beam. And light receiving means for emitting reflected light from the forward moving body and outputting an electric signal corresponding to the incident position; and measuring means for measuring a distance to the forward moving body based on the electric signal from the light receiving means. And a braking means for performing braking control based on a measurement value of the measuring means. 6. The light receiving means is a position sensor for outputting a photocurrent including information corresponding to an incident position.
The collision preventing device for a rail traveling vehicle according to the above. 7. The collision preventing device for a rail traveling vehicle according to claim 6, further comprising a retroreflector provided at a rear portion of the moving body with a horizontal direction as a longitudinal direction.