JPH06230097A - Moving body position detector - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a moving body position detecting device capable of simultaneously detecting a plurality of moving body positions with high accuracy. [Arrangement] A direction detecting means 3 which receives pulsed light from a plurality of targets and outputs light receiving position information on the measurement plane related to the directions of the targets, and a pulse from each target by the output of the direction detecting means 3. It is composed of a period detecting means 1 for obtaining the period of light, and a position detecting means 2 for obtaining the position of each target by sampling the output of the azimuth detecting means 3 based on the period data from the period detecting means 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving body position detecting device, and more particularly to a moving body position detecting device suitable for simultaneously detecting the positions of a plurality of moving bodies such as vehicles.

[0002]

2. Description of the Related Art In a conventional moving body position detecting device, continuous light from a moving body is received by an azimuth detecting means, and the center of gravity of the light is converted into two-dimensional position data by the controlling means.

Further, in order to avoid the influence of ambient light, the light output from the moving body is modulated into pulsed light having a constant cycle, and the output of the azimuth detecting means is sampled in synchronization with the modulation cycle. That is, as shown in FIG. 11, the control means samples the output of the azimuth detecting means at P1 when the light from the moving body is on and at P2 when the light is off,
The influence of ambient light was removed by obtaining the difference between the respective received light levels.

On the other hand, the control means samples the output of the azimuth detecting means at a constant cycle as shown in FIG. 12, and when light is detected, it measures the time from the rise of the light output to the rise of the next light output. The pulse modulation cycle of the light from the moving body is obtained by the following, and then the output of the azimuth detecting means is sampled in synchronization with the modulation cycle to remove the influence of ambient light.

[0005]

However, in the above-mentioned conventional example, when the light from the moving body is continuous light, the position of the center of gravity of the incident light is measured. Therefore, the two-dimensional position detecting element shown in FIG. 13 is used. As shown in FIG. 30, even if the lights A and B from the two moving bodies are received, the data of the center of gravity C of the lights A and B is output, and the positions of the two moving bodies cannot be detected.

Further, in the above-mentioned conventional example, when the light from the moving body is made into pulsed light of a constant cycle and the output of the azimuth detecting means is sampled in synchronization with it, the moving body and the azimuth detecting means should be separated. In addition to this, there is a problem in that in order to detect a plurality of moving body positions, the cycle of the pulsed light from each moving body must be complicated as shown in FIG.

Further, in the above-mentioned conventional example, first, the output of the azimuth detecting means is sampled at a constant cycle to obtain the pulse cycle of light from the moving body, and subsequently, when sampling is performed in synchronization with the cycle, 2 When the light from one moving body is received, there is a problem that the positions of two moving bodies cannot be detected because the output pattern from the azimuth detecting means becomes complicated as shown in FIG.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a moving body position detecting apparatus which is capable of remedying the disadvantages of the prior art and particularly capable of detecting a plurality of moving body positions simultaneously and accurately.

[0009]

Therefore, in the present invention, an azimuth detecting means for receiving pulsed light from a plurality of targets and outputting light receiving position information on the measurement plane related to the azimuths of the targets, and the azimuth detecting means. Cycle detection means for obtaining the cycle of the pulsed light from each target by the output of the detection means, and position detection means for sampling the output of the azimuth detection means based on the cycle data from this cycle detection means to obtain the position of each target It has a configuration that includes and. This aims to achieve the above-mentioned object.

[0010]

The azimuth detecting means outputs the two-dimensional information of the light receiving position on the measurement surface when receiving the pulsed light from the plurality of targets.

The cycle detecting means analyzes the sampling data of the output from the azimuth detecting means and obtains the cycle of the pulsed light from each target object based on the output level.

The position detecting means samples the output from the azimuth detecting means in synchronization with the cycle data detected by the cycle detecting means, and obtains the two-dimensional position of each target based on the sampled data.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

In the embodiment shown in FIG. 1, the azimuth detecting means 3 for receiving pulsed light from a plurality of targets and outputting the light receiving position information on the measurement plane related to the azimuths of the targets, and the azimuth detecting means 3.
Of the pulse light from each target by means of the output of 1 and the position detecting means for sampling the output of the azimuth detecting means 3 based on the cycle data from the cycle detecting means 1 to obtain the position of each target. 2 and.

Here, as the azimuth detecting means 3, as shown in FIG. 3, a filter 3a for transmitting only the light from the target and a two-dimensional position detecting element (PSD) for detecting the center of gravity of the light and converting it into an electric signal. ) 3b and a lens 3c for converging the light transmitted through the filter 3a onto the two-dimensional position detecting element 3b.
It is configured with and.

Further, as shown in FIGS. 4 and 5, the two-dimensional position detecting element 3b is formed on the surface of the flat plate-like silicon with P.
Layer, an N layer on the back surface, and an I layer in the middle, and the light incident on the surface is photoelectrically converted into four electrodes Y, Y ′, which are attached to the P layer as photocurrent. X,
It is divided and output from X '. The position data in the left-right direction (x direction) is output from the electrodes Y and Y ′, and the position data in the up-down direction (y
The position data (direction) is output from the electrodes X and X ′.

When a light spot is incident on the two-dimensional position detecting element 3b, a charge proportional to the light energy is generated at the incident position. The generated charge passes through the resistance layer, that is, the P layer as a photocurrent, and is output from each electrode. However, since the resistance layer is made to have a uniform resistance value over the entire surface, the photocurrent is distributed at a distance to the electrode. It is divided and extracted in inverse proportion.
Here, in the left-right direction (x direction), as shown in FIG. 6, the distance between the electrodes X and X ′ is L, the photocurrent is I ₀ , the current extracted from the electrode X is I ₁ , and the current extracted from the electrode X ′ is. If the generated current is I ₂ (I ₀ = I ₁ + I ₂ ), the following relationship is established.

(A) When the center of the two-dimensional position detecting element 3b is the origin,

I ₁ = I ₀ (1-2X _A / L) / 2 (1)

Here, X _A is the distance from the origin to the incident position.

I ₂ = I ₀ (1 + 2X _A / L) / 2 (2)

(I ₂ −I ₁ ) / (I ₂ + I ₁ ) = 2X _A / L (3)

I ₁ / I ₂ = (L−2X _A ) / (L + 2X _A ) (4)

(B) When the end of the two-dimensional position detecting element 3b is the origin,

I ₁ = I ₀ (L−X _B ) / L ... (5)

Here, X _B is the distance from the origin to the incident position.

I ₂ = I ₀ × X _B / L (6)

(I ₂ −I ₁ ) / (I ₂ + I ₁ ) = (2X _B −L) / L · · (7)

I ₁ / I ₂ = (L−X _B ) / X _B (8)

Thus, by obtaining the difference or ratio of I ₁ and I ₂ , there is no relation to the incident light energy as shown in the equations (3), (4), (7) and (8). Moreover, the incident position of light can be obtained.

Further, the cycle detecting means 1 and the position detecting means 2
Can also be implemented by a computer 300 as shown in FIG.

Next, the operation of this embodiment will be described with reference to the flowchart of FIG. Here, for the sake of simplicity, a case will be described in which the positions of two vehicles are detected as shown in FIG.

.. The vehicle 1 outputs pulsed light A having a preset cycle, and the vehicle 200 outputs pulsed light B having a preset cycle. For the sake of explanation, the pulsed light A from the vehicle 100 and the pulsed light B from the vehicle 200 have the same light quantity, but the light quantity is not limited to this.

.. The two-dimensional position detecting element 3b outputs data indicating the barycentric position of the received light from the electrodes Y, Y ', X, X'.

.. The cycle detecting means 1 samples the output from the two-dimensional position detecting element 3b at regular intervals (S1 in FIG. 7). Here, as shown in FIG.
Is located above the vehicle 2, the vertical direction (the y direction) from the two-dimensional position detecting element 3c when only the pulsed light A from the vehicle 1 is received as shown in FIGS. 8 and 10. ) The output becomes larger than that when only the pulsed light B from the vehicle 2 is received.

When the pulsed light A from the vehicle 1 and the pulsed light B from the vehicle 2 are received at the same time, the vertical (y-direction) output from the two-dimensional position detecting element 3c is as shown in FIG. Is a value corresponding to the barycentric position C of the pulsed light A and the pulsed light B, that is, a value between the value corresponding to the pulsed light A and the value corresponding to the pulsed light B as shown in FIGS. 8 and 10. .

That is, the pulsed light A from the vehicle 1 and the pulsed light B from the vehicle 2 have the same light quantity, and
Is above the vehicle 2 (+ direction of y), the output from the two-dimensional position detecting element 3c in the vertical direction (y direction), that is, the output level of the electrodes Y and Y ′ is expressed by the following equation (9). It is in.

(Pulse light A)> (Pulse light A + Pulse light B)> (Pulse B) (9)

On the contrary, when the pulsed light A from the vehicle 1 and the pulsed light B from the vehicle 2 have the same light quantity, and the vehicle 2 is above the vehicle 1 (+ direction of y), The vertical direction (y direction) output from the dimensional position detecting element 3c, that is, the output levels of the electrodes A and A'have the relationship of the following expression (10).

(Pulse light B)> (Pulse light A + Pulse light B)> (Pulse A) (10)

The above relationship is the same in the left-right direction (x direction), the pulse light A from the vehicle 1 and the pulse light B from the vehicle 2 have the same light quantity, and the vehicle 1 is the vehicle 2
When it is on the right side (+ direction of x), the left-right direction (x direction) output from the two-dimensional position detecting element 3c, that is, the output level of the electrodes X and X ′ has the relationship of the following equation (11). .

(Pulse light A)> (Pulse light A + Pulse light B)> (Pulse B) (11)

On the contrary, when the pulsed light A from the vehicle 1 and the pulsed light B from the vehicle 2 have the same light quantity, and the vehicle 2 is on the right side of the vehicle 1 (+ direction of x), The left-right direction (x direction) output from the dimensional position detecting element 3c, that is, the output levels of the electrodes X and X'have the relationship of the following expression (12).

(Pulse light B)> (Pulse light A + Pulse light B)> (Pulse A) (12)

The cycle detecting means 1 comprises a two-dimensional position detecting element 3
Analyze the sampling data from c. And FIG.
When the pulse light A from the vehicle 1 alone is received, the value corresponding to the pulse light B from the vehicle 2 alone is received, and the pulse light A and the pulse light B are received at the same time as shown in FIG. Corresponding values are obtained (S2 in FIG. 7).

.. Then, when the cycle detecting means 1 detects the value a corresponding to the case of only the pulsed light A from the vehicle 1 as shown in FIG. 8, it then corresponds to the case of only the pulsed light A from the vehicle 1. The time until the value a ′ is detected is measured, and the period of the pulsed light A is obtained. Next, similarly, when the value b corresponding to the case of only the pulsed light B from the vehicle 2 is detected, the time until the value b ′ corresponding to the case of only the pulsed light B from the vehicle 2 is detected is determined. Measurement is performed and the period of the pulsed light B is obtained (S3, 4 in FIG. 7).

.. Upon receiving the cycle data from the cycle detecting means 1, the position detecting means 2 samples the output of the two-dimensional position detecting element 3c in synchronization with the cycle of the pulse A and the cycle of the pulse B.

.. The position detecting means 2 analyzes the sampling data from the two-dimensional position detecting element 3c, and when it detects a value corresponding to only the pulsed light A in the cycle of the pulse A, it outputs (3) from the outputs of the electrodes X and X ′. Formula, Formula (4),
The position of the vehicle 1 in the left-right direction (x direction) is obtained by using either of the equations (7) and (8), and similarly, the position of the vehicle 1 in the up-down direction (y direction) is calculated from the outputs of the electrodes Y and Y ′. The position is obtained (S5 in FIG. 7).

Further, when the value corresponding to only the pulsed light B is detected in the cycle of the pulse B, the formulas (3), (4), (7) and (8) are obtained from the outputs of the electrodes X and X ′. The position of the vehicle 2 in the left-right direction (x direction) is obtained using any one of the formulas, and similarly, the position of the vehicle 2 in the vertical direction (y
Direction) is obtained (S5 in FIG. 7).

If the pulse A and the pulse B are sampled at the same time, the pulse A and the pulse B are separated into a value corresponding to the pulse A and a value corresponding to the pulse B on the basis of the immediately preceding sampling data, and the same as above. Position of vehicle 1 and vehicle 2
Is obtained (S6 in FIG. 7).

As described above, since the positions of a plurality of moving bodies can be detected at the same time, it is possible to control the vehicle traveling on an uneven terrain or the automatic guided vehicle in the factory in real time.

In the above embodiment, the case where there are two moving bodies has been described. However, even when there are three or more moving bodies, the position of each moving body can be detected at the same time by the same processing.

[0053]

Since the present invention is constructed and functions as described above, according to this, it is possible to separate and extract light from a plurality of light sources with one azimuth detecting means, which results in a plurality of moving bodies. The position can be detected simultaneously with high accuracy,
It is possible to provide an unprecedented excellent moving body position detection device that enables real-time control of vehicles, autonomous traveling of vehicles, control of joint work, and the like.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a specific example of FIG.

FIG. 3 is a configuration diagram showing details of an azimuth detecting means in FIG.

FIG. 4 is an explanatory diagram showing electrode positions of the two-dimensional position detecting element in FIG.

5 is an explanatory diagram showing the operation of the two-dimensional position detecting element in FIG. 3 in the y direction.

6 is an explanatory diagram showing an operation of the two-dimensional position detecting element in FIG. 3 in the x direction.

FIG. 7 is a flow chart for explaining the operation of the embodiment of FIG.

8 is an explanatory diagram for explaining an output level of the two-dimensional position detecting element in FIG.

9 is an explanatory diagram showing an example of light receiving positions of the two-dimensional position detecting element in FIG.

10 is an explanatory diagram showing an output with respect to a light receiving signal of the two-dimensional position detecting element in FIG.

FIG. 11 is an explanatory diagram showing the operation of the control means in the conventional example.

FIG. 12 is an explanatory diagram showing an example of y-direction output of a two-dimensional position detecting element in a conventional example.

FIG. 13 is an explanatory diagram showing a light receiving example of a two-dimensional position detecting element in a conventional example.

FIG. 14 is an explanatory diagram showing an output example of pulsed light from a moving body in a conventional example.

FIG. 15 is an explanatory diagram showing an output example of a received light signal in a conventional example.

[Explanation of symbols]

 1 cycle detecting means 2 position detecting means 3 azimuth detecting means 3a filter 3b two-dimensional position detecting element (PSD) 3c lens

Claims (1)

[Claims] 1. An azimuth detecting means for receiving pulsed light from a plurality of targets and outputting light-receiving position information on a measuring surface related to the azimuths of the targets, and an output from the azimuth detecting means for detecting the azimuth from each target. Cycle detection means for obtaining the cycle of the pulsed light,
A moving body position detecting device comprising: position detecting means for sampling the output of the azimuth detecting means based on the cycle data from the cycle detecting means to obtain the position of each target.