JP3039636B2 - Object outline recognition device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an object shape recognizing device for recognizing the shape of an object to be measured or an obstacle.
In particular, the present invention relates to an object outline recognition device mounted on a moving body or the like.

[0002]

2. Description of the Related Art In general, a device using light as a medium has been known as this type of object outline recognition device. For example, a method of recognizing an object outline by image processing using a camera to image an object or the like. And a method using the principle of triangulation is known.

[0003] Among these object outline recognizing devices, a method using a triangulation method is disclosed in, for example, Japanese Patent Application Laid-Open No. 5-332737.
(Hereinafter referred to as “prior art 1”). In the prior art 1, while the light (slit light) passing through the slit is blinked and illuminated on the object to be measured, an optical image generated on the surface of the object is photographed by a CCD camera, and image processing is performed. Recognizes the shape of the measured object.

Further, as an object outline recognition apparatus, an apparatus using a three-dimensional measurement method for recognizing the shape of an object to be measured by combining a laser range finder and a scanner is known. However, for example, JP-A-7-20
No. 8946 (hereinafter referred to as “prior art 2”). In the prior art 2, a laser beam is emitted from a scanner capable of detecting an emission angle of a laser beam to an object to be measured, and a distance from the scanner to the object is measured for each laser beam emission angle. The shape of the measured object is recognized based on the measurement result.

[0005]

In the prior art 1 described above, the shape of the measured object is accurately measured because the shape of the measured object is recognized using the principle of the triangulation. In principle, it is necessary to set the optical system with a distance between the transmitting side and the receiving side of the object shape recognition apparatus in principle. As described above, when the optical system is set apart from the transmitting side and the receiving side, not only the optical system becomes large, but also the device itself becomes heavy, which is not suitable as a sensor for mounting on a moving body. is there. That is, in the object shape recognition device using the triangulation method, there is a problem that the optical system is large, heavy, and expensive.

On the other hand, in the above-mentioned prior art 2, the scan pattern cannot be changed at a high speed because the laser beam is scanned with a predetermined scan pattern using a mechanical scanner. Is a problem. In addition, in the prior art 2,
Since the entire predetermined field of view is scanned, unnecessary portions where the object to be measured does not exist are also scanned, and furthermore, there is a problem that a scan time is required.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an object outline recognizing apparatus which can be mounted on a high-speed moving body or the like by shortening an outline recognizing time of a target object by using three-dimensional measurement using laser.

[0008]

According to the present invention, there is provided a three-dimensional measuring apparatus which is used for three-dimensionally measuring and recognizing an outer shape of an object to be measured by using a laser beam. Scanning means for scanning and transmitting as a transmitting laser light, detecting means for receiving a reflected laser light according to the transmitting laser light and detecting it as a reception signal, and based on a time from transmission of the laser light to reception of the reception signal. Distance calculating means for determining the presence or absence of the object to be measured and the distance to the object as a distance measurement value, and controlling the scanning means in accordance with the presence or absence of the object to scan the laser light to perform the measurement. Processing means for recognizing the outer shape of the object to be measured based on the distance value.

The scanning means includes a first deflecting element for deflecting the laser light in the ± X-axis direction in the XY coordinate system, and a second deflecting element for deflecting the laser light in the ± Y-axis direction. The processing means has a function of electrically controlling the deflection angles of the first and second deflecting elements in accordance with the presence or absence of the device under test to emit the transmitted laser light.

[0010] The scanning means and the detecting means may be mounted on a gimbal. In this case, a laser oscillator for oscillating laser light and the scanning means are connected by an optical fiber system. Further, an image sensor for generating an image from the reflected laser light and providing the image to the processing unit may be provided. In this case, the image sensor is mounted on the gimbal.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

Referring to FIG. 1, the illustrated object outline recognition apparatus includes a laser oscillator 1, an electronic scanning device 2, a light receiving system 3,
The laser oscillator 1, the distance calculation unit 5, and the signal processing unit 6 are provided with power from a power supply unit 9 (see FIG. 1). , The power supply line is not shown). Then, pulse laser light is oscillated by the laser oscillator 1, and the pulse laser light is guided to the electronic scanning device 2.

The electronic scanning device 2 is provided with a deflecting element having a high-speed response. Specifically, as shown in FIG. 2, the electronic scanning device 2 is used to deflect a laser beam in the X-axis direction. An X-axis deflecting element 21 and a Y-axis deflecting element 22 for deflecting laser light in the Y-axis direction are provided. The X-axis deflection element 21 and the Y-axis deflection element 22
For example, an acousto-optic element or an electro-optic element is used.

First, a first deflection angle designating signal indicating the deflection angle of the first step is transmitted from the signal processing unit 6, and the electronic scanning device 2 performs the deflection according to the deflection angle of the first step. The pulse laser beam is deflected at an angle. That is, the X-axis deflection element 21 and the Y-axis deflection element 22 change their deflection angles according to the first deflection angle designation signal. As a result, the pulse laser light is deflected in the X-axis direction and the Y-axis direction by the X-axis deflection element 21 and the Y-axis deflection element 22 by an amount defined by the deflection angle in the first step, respectively. It is transmitted to a device under test (not shown). The deflected laser light is reflected by the object to be measured, and the laser reflected light is received by the light receiving system 3 as received laser light, guided to the photodetector 4, and converted into a received signal. Then, the received signal is provided to the distance calculation unit 5.

A transmission signal is supplied from the laser oscillator 1 to the distance calculation unit 5 in synchronization with the pulse laser output, whereby the distance calculation unit 5 starts measuring time. Then, distance calculating section 5 measures the time until the received signal is received. That is, the distance calculation unit 5 measures the time from receiving the transmission signal to receiving the reception signal output from the photodetector 4 as the measurement time. Then, the distance calculation unit 5 obtains the distance to the measured object as a distance measurement value according to the measurement time.

When the scanning laser beam does not hit the object to be measured, naturally, there is no received signal, and at this time, the distance measurement value becomes invalid. That is, if the reception signal is not received even after a preset time (a sufficiently long distance) has elapsed after receiving the transmission signal, the distance calculation unit 5 invalidates the distance measurement value.

Upon receiving the distance measurement value, the signal processing unit 6 specifies the deflection angle of the next step (the deflection angle of the second step) and outputs a second deflection angle specifying signal to the electronic scanning device 2. Then, the electronic scanning device 2 changes the deflection angle in accordance with the deflection angle in the second step and outputs the deflection laser light.

As described above, the signal processing unit 6 sequentially changes the deflection angle, that is, scans the laser beam to measure the distance to the object to be measured, and determines the distance to the object according to the deflection angle and the distance measurement value. Recognize the external shape of the device under test.

Here, referring to FIG. 3, FIG. 3 shows a scanning example of the laser beam oscillated from the electronic scanning device 2, and in FIG. 3, each cell shows an XY plane. In FIG. 3, a change in the angle when the laser beam is continuously scanned is discretely and simulated. For example, the laser beam is transmitted for each cell.

In FIG. 3, an ellipse indicated by a thick line indicates that the elliptical object to be measured is located in the air, and a circle indicates that the distance measurement value obtained as an output of the distance calculation unit 5 is valid. Is shown. On the other hand, the x mark indicates that the distance measurement value is invalid, that is, indicates a distant distance without irradiating the object to be measured with the laser beam, or that only a part of the laser beam hits the object to be measured, and as a result, the laser reflection The case where the distance cannot be measured due to weak light is shown.

Here, referring to FIGS. 4 to 7 in addition to FIGS. 1 and 3, first, as shown in FIG. 3, a target object to be measured is searched (step S1). Find out. In other words, as described above, until the distance measurement value is valid,
The laser beam is scanned to check whether or not the distance measurement value has become valid (step S2). Then, when the distance measurement value becomes valid, it is determined that the measured object has been found.

First, referring to FIG. 4, assuming that the distance value becomes effective as a result of the laser light being applied to the vicinity of the center of the object to be measured, the signal processing section 6 moves in the + Y direction shown in FIG. The deflection angle is changed by one step. Then, it is checked again whether the distance measurement value is valid (step S3). If the distance measurement value is valid, the signal processing unit 6 further changes the one-step deflection angle in the + Y direction to check whether the distance measurement value is valid. As described above, the signal processing section 6 changes the deflection angle by one step in the + Y direction shown in FIG. 3, that is, sequentially changes the deflection angle by one step in the + Y direction, and performs the distance measurement as described above. Will be.

In this way, when the distance measurement is performed by sequentially changing the deflection angle in the + Y direction one step at a time, when it is determined that the distance measurement value is invalid, that is, when the distance measurement value changes from valid to invalid. , The signal processing unit 6 detects the position of the object to be measured in the + Y direction.

As described above, when the deviated position in the + Y direction is detected, the signal processing unit 6 measures the distance by changing the deflection angle by one step in the + X direction from this position (step S).
5) Check whether or not the distance measurement value is valid (step S)
6). If the distance measurement value is invalid, the signal processing unit 6 changes the deflection angle by one step in the -Y direction from the position changed by one step in the + X direction to perform the distance measurement (step S7). It is checked whether or not it is valid (step S8). If the distance measurement value is invalid again, the signal processing unit 6 again measures the distance by changing the deflection angle by one step in the −Y direction (step S9), and checks whether the distance measurement value is valid (step S9). Step S10). If the distance measurement value is invalid, the process shifts to B shown in FIG.

On the other hand, if the distance measurement value is valid in step S6, the signal processing unit 6 measures the distance by changing the deflection angle in the + Y direction (step S11). It is checked whether or not there is (step S12). If the distance measurement value is valid, the flow returns to step S11 to change the deflection angle by one step in the + Y direction again to perform distance measurement. If the distance measurement value is invalid in step S12, step S5
The distance measurement is performed by changing the deflection angle by one step in the + X direction.

Similarly, in each of steps S8 and S10, if the distance measurement value is valid, the process returns to step S5, and distance measurement is performed by changing the deflection angle by one step in the + X direction.

In this way, while changing the deflection angle in the + X direction, if the distance measurement value is invalid, the deflection angle is changed in the -Y direction. If the distance measurement value is valid, the deflection angle is changed in + Y direction. The deflection angle is repeatedly changed until the distance measurement value becomes invalid three consecutive times. Then, when the deflection angle is changed in the -Y direction and the distance measurement value becomes invalid three consecutive times, the flow shifts to B shown in FIG.

Referring to FIG. 5, step S1 shown in FIG.
At 0, if the distance measurement value is invalid, the signal processing unit 6
The distance is measured by changing the deflection angle by one step in the -X direction (step S13), and it is checked whether or not the measured distance is valid (step S14). If the distance measurement value is invalid, the signal processing section 6 changes the deflection angle by one step in the -X direction again to perform distance measurement (step S15), and checks whether the distance measurement value is valid (step S15). S16). If the distance measurement value is invalid again, the signal processing unit 6 further reduces the deflection angle by-
Distance measurement is performed by changing one step in the X direction (step S
17), it is checked whether or not the distance measurement value is valid (step S18). If the distance measurement value is invalid, the flow shifts to C shown in FIG.

If the measured distance value is valid in step S14, the signal processing section 6 measures the distance by changing the deflection angle by one step in the -Y direction (step S19), and the measured distance value is valid. It is checked whether it is (Step S20). If the distance measurement value is invalid, the process proceeds to step S15,
Distance measurement is performed by changing the deflection angle by one step in the -X direction.

If the distance measurement value is valid in step S20, the signal processing unit 6 measures the distance by changing the deflection angle by one step in the + X direction (step S21), and determines whether the distance measurement value is valid. Is checked (step S22). And
If the distance measurement value is invalid, the process returns to step S19 to change the deflection angle by one step in the -Y direction to perform distance measurement. on the other hand,
In step S22, if the distance measurement value is valid, the process returns to step S21 to change the deflection angle by one step in the + X direction to perform distance measurement.

In this manner, while the deflection angle is changed in the -Y direction, if the distance measurement value is invalid, the deflection angle is changed in the -X direction. If the distance measurement value is valid, the deflection angle is changed. The deflection angle is changed repeatedly in the + X direction until the distance measurement value becomes invalid three consecutive times. Then, when the deflection angle is changed in the −X direction and the distance measurement value becomes invalid three consecutive times, the flow shifts to C shown in FIG.

Referring to FIG. 6, step S1 shown in FIG.
If the measured distance value is invalid in step 8, the signal processing unit 6 measures the distance by changing the deflection angle by one step in the + Y direction (step S24), and checks whether the measured distance value is valid (step S24). Step S25). If the distance measurement value is invalid, the signal processor 6 changes the deflection angle by one step in the + Y direction again to perform distance measurement (step S26), and checks whether the distance measurement value is valid (step S27). ). If the distance measurement value is invalid again, the signal processor 6 further sets the deflection angle to + Y
The distance is measured by changing the direction by one step (step S2).
8) Check whether the measured distance value is valid or not (step S)
29). If the distance measurement value is invalid, the process shifts to D shown in FIG.

If the measured distance value is valid in step S25, the signal processing unit 6 measures the distance by changing the deflection angle by one step in the -X direction (step S30), and the measured distance value is valid. It is checked whether it is (step S31). If the distance measurement value is invalid, the process proceeds to step S26,
The distance is measured by changing the deflection angle by one step in the + Y direction.

If the distance measurement value is valid in step S31, the signal processing unit 6 measures the distance by changing the deflection angle by one step in the -Y direction (step S32), and determines whether the distance measurement value is valid. It is checked whether or not it is (step S33). And
If the distance measurement value is invalid, the process returns to step S30 to change the deflection angle by one step in the -X direction to perform distance measurement. on the other hand,
If the distance measurement value is valid in step S33, the process returns to step S32 to change the deflection angle by one step in the -Y direction to perform distance measurement.

As described above, while the deflection angle is changed in the -X direction, if the distance measurement value is invalid, the deflection angle is changed in the + Y direction. If the distance measurement value is valid, the deflection angle is changed to-. By changing the deflection angle in the Y direction, the deflection angle is repeatedly changed until the distance measurement value becomes invalid three consecutive times. Then, when the deflection angle is changed in the + Y direction and the distance measurement value becomes invalid three consecutive times, the flow shifts to D shown in FIG.

Referring to FIG. 7, step S2 shown in FIG.
In step 9, if the distance measurement value is invalid, the signal processing unit 6 measures the distance by changing the deflection angle by one step in the + X direction (step S34), and checks whether the distance measurement value is valid (step S34). Step S35). If the distance measurement value is invalid, the signal processing unit 6 measures the distance again by changing the deflection angle by one step in the + X direction (step S36), and checks whether the distance measurement value is valid (step S37). ). If the distance measurement value is invalid again, the signal processor 6 further sets the deflection angle to + X
The distance is measured by changing the direction by one step (step S3).
8) Check whether the measured distance value is valid or not (step S)
39). If the distance measurement value is invalid, the flow shifts to A shown in FIG.

If the distance measurement value is valid in step S35, the signal processing section 6 measures the distance by changing the deflection angle by one step in the + Y direction (step S40), and determines whether the distance measurement value is valid. It is checked whether or not it is (step S41). If the distance measurement value is invalid, the process proceeds to step S36,
Distance measurement is performed by changing the deflection angle by one step in the + X direction.

If the measured distance value is valid in step S41, the signal processing section 6 measures the distance by changing the deflection angle by one step in the -X direction (step S42), and determines whether the measured distance value is valid. It is checked whether or not it is (step S43). And
If the distance measurement value is invalid, the process returns to step S40 to change the deflection angle by one step in the + Y direction to perform distance measurement. on the other hand,
In step S43, if the distance measurement value is valid, the process returns to step S42 to change the deflection angle by one step in the -X direction to perform distance measurement.

As described above, while the deflection angle is changed in the + Y direction, if the distance measurement value is invalid, the deflection angle is changed in the + X direction. If the distance measurement value is valid, the deflection angle is changed to -X. The deflection angle is repeatedly changed until the distance measurement value becomes invalid three consecutive times. Then, when the deflection angle is changed in the + X direction and the distance measurement value becomes invalid three consecutive times, the flow shifts to A shown in FIG.

Using the deflection angle and the distance measurement value obtained as a result of the operations shown in FIGS. 4 to 7, the signal processing section 6 recognizes the outer shape of the object to be measured. In the above example, when the distance measurement value is invalidated three times consecutively, the processing operation is shifted. However, the number of times is not limited to three, and the number of invalidations is set according to the outer shape of the measured object. Can be changed.

As described above, in the example shown in FIG. 1, it is not necessary to scan over the entire surface of the object to obtain a distance measurement value. Is obtained, the number of times of distance measurement can be reduced, and as a result, scanning can be speeded up and the outer shape recognition time of the measured object can be shortened.

Further, the deflection angle per step in the electronic scanning device 2 can be set electrically, and therefore, the deflection angle per step can be set according to the expected angle of the object to be measured. . As a result, it is possible to set the deflection angle per step so that the number of times of distance measurement is reduced even if the object to be measured is large, and to keep the scan speed constant at a high speed.

Next, another example of the present invention will be described with reference to FIG. In FIG. 8, the same components as those in FIG. 1 are denoted by the same reference numerals.

Generally, in the electronic scanning device 2, there is a limit on the deflection angle that can be scanned. For this reason, in the illustrated example, the electronic scanning device 2, the light receiving system 3, and the photodetector 4 are mounted on the gimbal 8. In addition, this gimbal 8
An image sensor 7 for taking an image is mounted,
The gimbal 8 increases the deflection direction of the system formed by the electronic scanning device 2, the light receiving system 3, the light detector 4, and the image sensor 7. In the illustrated example, the electronic scanning device 2 and the laser oscillator 1 are connected by the optical fiber system 10, so that the laser beam can be guided to the electronic scanning device 2 even if the gimbal 8 moves. The laser beam is guided to the electronic scanning device 2 with its divergence angle optically minimized at the emission section of the optical fiber system 10.

A beam splitter 7 a is arranged between the light receiving system 3 and the photodetector 4, and the received laser light is split by the beam splitter 7 a and applied to the photodetector 4 and the image sensor 8. The image captured by the image sensor 8 is provided to the signal processing unit 6.

The image sensor 7 has an angle of view larger than the angle of view of the electronic scanning device 2, thereby searching for a target object to be measured while changing the deflection direction of the gimbal 8. When the signal processing unit 6 captures the target DUT at the center of the image sensor 7, the electronic scanning device 2 performs high-speed scanning as described above to recognize the outer shape of the DUT.

[0047]

As described above, according to the present invention, it is not necessary to perform a full scan on the object to be measured to obtain a distance measurement value. As a result, the number of times of distance measurement can be reduced, and as a result, scanning can be speeded up, and the shape of the measured object can be recognized in a short time.

Further, according to the present invention, if the deflection angle per step of the electronic scanning device is set to a deflection angle suitable for the expected angle of the measured object, the number of times of distance measurement can be increased even when the measured object becomes large. As a result, there is an effect that the scanning speed can be kept high and constant even when the object to be measured becomes large.

In addition, according to the present invention, an electronic scanning device,
Since the light receiving system, the light detector, and the image sensor are mounted on the gimbal, the deflection direction of the laser beam can be increased, and as a result, the scanning direction can be increased.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an example of an object outline recognition device according to the present invention.

FIG. 2 is a diagram showing an example of the electronic scanning device shown in FIG.

FIG. 3 is a diagram showing an example of a scan in the object outline recognition device shown in FIG. 1;

FIG. 4 is a flowchart illustrating an example of a scanning operation of the object outline recognition device shown in FIG. 1;

FIG. 5 is a flowchart for explaining an example of a scanning operation of the object outline recognition device shown in FIG. 1;

FIG. 6 is a flowchart illustrating an example of a scanning operation of the object outline recognition device shown in FIG. 1;

FIG. 7 is a flowchart illustrating an example of a scanning operation of the object outline recognition device shown in FIG. 1;

FIG. 8 is a block diagram showing another example of the object outline recognition device according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 laser oscillator 2 electronic scanning device 3 light receiving system 4 light detector 5 distance calculation unit 6 signal processing unit 7 image sensor 8 gimbal 9 power supply unit 10 optical fiber system

Claims (8)

(57) [Claims] 1. A three-dimensional measuring device used for three-dimensionally measuring and recognizing an outer shape of an object to be measured using a laser beam, wherein the scanning device scans a laser beam and transmits the laser beam as a transmitted laser beam. Means, and detecting means for receiving a reflected laser beam according to the transmitted laser beam and detecting the reflected laser beam as a received signal,
Distance calculation means for determining the presence or absence of the object to be measured and the distance to the object as a distance measurement value based on the time from transmission of the laser light to reception of the reception signal, and according to the presence or absence of the object to be measured Processing means for controlling the scanning means to scan the laser beam and recognize the outer shape of the object to be measured based on the distance measurement value. 2. The object outline recognizing device according to claim 1, wherein said scanning means deflects said laser light in ± X-axis directions in an XY coordinate system, and said laser light. And a second deflecting element for deflecting in the ± Y-axis direction. 3. The object outline recognizing device according to claim 2, further comprising: a laser oscillator that oscillates the laser light, wherein the laser oscillator supplies a transmission signal synchronized with the laser light to the distance calculation unit. An object shape recognizing device characterized in that: 4. The apparatus for recognizing an object outline according to claim 2, wherein the processing unit electrically controls deflection angles of the first and second deflection elements according to the presence or absence of the object to be measured. And transmitting the transmission laser light. 5. An object outline recognition apparatus according to claim 1, wherein said scanning means and said detection means are mounted on a gimbal. 6. The object outline recognizing device according to claim 5, further comprising: a laser oscillator that oscillates the laser light, wherein the scanning unit is coupled to the laser oscillator by an optical fiber system. Object outline recognition device. 7. The object outline recognizing device according to claim 5, wherein the detection unit detects the reception signal in accordance with the light receiving system that receives the reflected laser light as the reception laser light and the reception laser light. An object shape recognizing device, comprising: a light detector. 8. The object outline recognition device according to claim 7, further comprising: an image sensor that receives the reception laser light, generates an image from the reception laser light, and provides the processing unit with the image. An object shape recognizing device, wherein a sensor is mounted on the gimbal.