JPH10111126A - Distance detecting device with measuring member correction - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect distance with high accuracy by photographing the reflecting light image of an object, detecting the distance to the photographed part from video signals, determining the kind of the member of the photographed part from the characteristics of signal waveforms, and correcting the detected distance on the basis of the determined kind of the member. SOLUTION: An object 1 is irradiated with light from a light source 2 formed of a conductive laser, and the reflecting light 4 is converted into video signals 5 by a light detecting element 11. The signals 5 are converted from analog to digital from by an A/D converting means 7a, the center of the reflecting light is calculated by an optical center calculating means 7b, and the optical center is converted to distance by a distance converting means 7c. A determining part 8 determines the kind of the member of a photographed part on the characteristics of video signal waveforms, and a correcting part 10 corrects the detected distance on the basis of the determined kind of the member. The correcting part 10 is provided with a correction table 9 according to the kind of each member of the object 1, and this is used according to the kind of a member to enable appropriate correction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distance detecting device with a measuring member correction for measuring the distance of an object composed of a plurality of types of members.

[0002]

2. Description of the Related Art In an optical (eg, triangulation) distance measuring detector used for detecting the distance of an object composed of various materials such as metals such as a body of a vehicle, linearity is slightly affected by the object. different.

[0003] Usually, an adjuster for correcting the target mark is provided, and switching is performed manually or by an external signal.

[0004]

In particular, different types (materials, materials, surface treatments, etc.) of each part in a body of a vehicle body.
Since there is a linearity deviation in the measurement distance depending on the type of member, there is a problem that accurate distance correction cannot be performed simply by fixing the correction or inputting an external signal. Was.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems. In an optical distance detector, the detection distance is corrected appropriately in accordance with the type of the object member. It is an object of the present invention to provide a distance detecting device with a measuring member correction that enables distance detection with high accuracy.

[0006]

The present invention has the following arrangement to solve the above-mentioned problems. The invention according to claim 1 is an optical distance detector that irradiates an object with light and detects a distance to the object by reflected light from the object,
An imaging unit that captures a reflected light image of an object made of a plurality of types of members to obtain a video signal; a distance detection unit that detects a distance to a shooting region of the object based on the obtained video signal; A means for determining the type of member of the imaging region based on the characteristics of the detected video signal waveform; and a correcting unit for correcting the detection distance based on the determined type of member. It is a detection device.

According to a second aspect of the present invention, the determination of the type of the member is made by analyzing the height, width, and frequency of the video signal waveform. Device.

According to a third aspect of the present invention, the correction means has a correction table corresponding to the type of each member of the object, and switches between the correction tables according to the determined member type. The distance detecting device with a measuring member correction according to claim 1 or 2, wherein:

According to a fourth aspect of the present invention, in the correction table according to the third aspect, the type of the member is determined according to the presence or absence of a metal material, a resin material, or a surface treatment. It is a distance detection device.

According to the first aspect of the present invention, a video signal is obtained by imaging a reflected light image of an object composed of a plurality of types of members, and the distance to the imaging region of the object is determined based on the obtained video signal. To detect. At this time, the characteristics of the obtained video signal waveform vary depending on the reflectance and the interference rate of the measuring member. Therefore, the height, width, and interference fringes of the captured video signal waveform vary depending on the type of the member. Therefore, the height, width, and frequency of the video signal waveform are analyzed to determine the type of member of the imaging region, and the detection distance is corrected based on the determined type of member. Therefore, the type of the member can be self-recognized, the linearity can be corrected according to the type of the member, and the distance to the object can be measured with high accuracy.

The characteristics of the obtained video signal waveform are as follows:
It depends on the reflectance and the interference rate of the measuring member. Therefore, the height, width, and interference fringes of the captured video signal waveform vary depending on the type of the member. Therefore, in the invention of claim 2, since the height, width, and frequency are analyzed from the video signal waveform, the material can be accurately determined.

According to the third aspect of the present invention, the correction means includes:
Since a correction table corresponding to the type of each member of the object is provided and this correction table is used according to the determined member type, appropriate correction can be performed according to the type of each member.

According to the fourth aspect of the present invention, the correction table can be corrected more accurately because the type of the member is in accordance with the presence or absence of a metal material, a resin material, or a surface treatment.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is an explanatory diagram of the entire configuration of a distance detecting device with a measuring member correction according to an embodiment, FIG. 2 is an explanatory block diagram of a detecting unit of the distance detecting device, FIG. 3 is a detection and correction flowchart of the distance detecting device, and FIG. FIG. 5 is an explanatory diagram of a linearity characteristic according to a material, FIG. 6 is an explanatory diagram of a correction table example, and FIG. 7 is an explanatory diagram of a video waveform example.

As shown in FIG. 1, the distance detecting device irradiates light 3 from a light source 2 to an object 1 to be measured and detects the distance to the object 1 by reflected light 4 from the object 1. The present invention relates to an optical distance detector.

The distance detecting device includes an imaging sensor unit 6 for obtaining a video signal 5 by capturing a reflected light image of the object 1 composed of a plurality of types of members, such as a vehicle body, and an object sensor based on the obtained video signal. A distance detecting unit 7 for detecting a distance to an imaging part of an object, and a characteristic of an obtained video signal waveform,
The apparatus includes a determination unit 8 for determining the type of member of the imaging region and a correction unit 10 for correcting the detection distance based on a correction table 9 corresponding to the determined type of member.

The image sensor 6 irradiates the object 1 with collimated light from a light source 2 composed of a semiconductor laser, and reflects the reflected light 4 on a photodetector 11 composed of a PSD, a CCD or the like.
The distance detecting unit 7, the judging unit 8 and the correcting unit 10 for converting the video signal into a video signal are provided in the controller 12 of the detecting device. In this case, the distance detecting unit 7 is a light detecting element 1
An A / D conversion stage 7a for converting an analog video signal output from 1 into a digital signal, an optical centroid calculation stage 7b for calculating a centroid of reflected light from the digital video signal, and a distance conversion stage for converting the optical centroid into a distance 7c, and the correction unit 10 corrects the conversion distance with the correction table 9 based on the output of the determination unit 8.

As shown in FIG. 2, the determination unit 8 in the controller 12 includes an analog filter (BPF) 13a for extracting a first frequency band 1 from an analog video signal.
An analog filter (BPF) 13b for extracting a second frequency band 2 from the video signal, and a first frequency band 1
, An integrator b that calculates an area S2 of the second frequency band 2, and a work material determiner 15 that determines the material of a member (work) from the calculated area.
And the correction unit 10 is made of a material (for example, SPC material, U
The correction distances are corrected by switching the correction tables 9a, 9b, 9c for each of the members, and the correction tables 9a, 9b, 9c for each material of the members.

Here, the type of the member is determined by analyzing the height, width and frequency of the video signal waveform. First, the correction table 9 (9a, 9b, 9c)
The type of the member depends on whether a metal material, a resin material, or a surface treatment is performed.

In the distance detecting apparatus according to the embodiment, a reflected light image 3 of the object 1 composed of a plurality of members is taken to obtain a video signal, and the video signal is obtained based on the obtained video signal. When detecting the distance, the determining unit 8 determines the type of the member of the imaging region based on the characteristics of the obtained video signal waveform, and the correcting unit 10 corrects the detection distance based on the determined type of member.

Next, the determination unit 8 in the controller 12
The operation of the correction unit 10 will be described based on the flowchart of FIG. Note that the case of three materials will be described.

First, a video signal is input (step (S
1), predetermined first frequency band 1 (f ₁ H
z) is extracted (S2). Then, the area S1 of the extracted first frequency band 1 is calculated (S3).

Next, a predetermined second frequency band 2 (f ₁
Hz) is extracted (S4). Then, the area S2 of the extracted second frequency band 2 is calculated (S5).

The area of each of the frequency bands 1 and 2 has a predetermined value α1,
It is determined whether all of them exceed α2 (S6). If it exceeds (S6: yes), it is determined that the material is 3 (S7),
The distance detection value (measured value) is corrected using the data of the correction table for the material 3 (S8).

If the frequency band is not exceeded in S6, it is determined whether or not the area of each of the frequency bands 1 and 2 exceeds any of the predetermined values β1 and β2 (S9). If it exceeds (S9: y
es), the material 2 is determined (S10), and the distance detection value (measured value) is corrected using the data of the correction table for the material 2 (S10).
11).

If it does not exceed the determination in S9, it is determined whether the area of each of the frequency bands 1 and 2 exceeds any of the predetermined values γ1 and γ2 (S12). If it exceeds (S1
2: yes), it is determined that the material is material 1 (S13), and the distance detection value (measured value) is corrected using the data of the correction table for material 1 (S14). If it is not exceeded in S12, no correction is made (S15).

Here, the linearity characteristic of the target object is
The light is divided into three types shown in FIG. 4 depending on how the irradiated light is reflected. FIG. 4A shows a diffuse reflection object (white paper,
(B) shows a regular reflection object (metal object, bake plate, etc.), and (c) shows a translucent object (transparent plastic, acrylic plate, etc.). Among them, the diffuse reflection object can be measured most accurately, and the regular reflection object and the translucent object have poor accuracy.

In the measuring apparatus of the present embodiment, the relationship between the distance from the center of gravity of the light is determined by calibrating with a diffuse reflection object such as a white ceramic. In addition, a metal object receives a different waveform depending on the unevenness of the surface. The shape of the waveform depends on the metal and surface treatment. 5 (a) to 5 (c)
Shows examples of linearity characteristics of each of the materials 1 to 3 based on white ceramic.

FIG. 6 is an example of a correction table for the material 1 and shows a correction table in which an error from the white ceramic reference is added.

The method for recognizing the material of the object (work) is as follows.
It is assumed that the video signal waveform captured in step 1 has different properties as shown in FIGS. 7 (a) to 7 (c). As can be seen from FIG. 7, the frequency at which the unevenness of the waveform appears differs depending on the material. Therefore, a frequency band that captures the characteristics of the material may be picked up from each video signal. FIG. 3 above
In the flowchart of FIG.
2 is picked up, the material is determined from the areas of the frequency bands 1 and 2, and the determination accuracy is improved.

According to the embodiment, the type of the member can be self-recognized, the linearity can be corrected according to the type of the member, and the distance to the object can be measured with high accuracy.

The correction section 10 has a correction table 9 corresponding to the type of each member of the object 1. The correction table is used according to the determined member type. Appropriate correction can be made in response to

The correction table 9 can be corrected more accurately because the type of the member is determined according to the presence or absence of a metal material or a resin material or surface treatment.

In the above embodiment, the material is determined by analyzing the frequency band area of the video signal.
In the present invention, the material determination based on the video signal is not limited to this, and it is needless to say that the height or width of the video signal is taken into account, and that the frequency analysis is performed by another method.

[0035]

As described above, according to the first aspect of the present invention, the type of a member can be self-recognized, the linearity can be corrected according to the type of the member, and the distance to the object can be measured accurately.

According to the second aspect of the invention, since the height, width, and frequency are analyzed from the video signal waveform, the material can be accurately determined.

According to the third aspect of the invention, an appropriate correction can be made according to the type of each member.

According to the fourth aspect of the invention, more accurate correction is possible.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an overall configuration of a distance detection device with a measurement member correction according to an embodiment.

FIG. 2 is an explanatory block diagram of a detection unit of the distance detection device.

FIG. 3 is a detection and correction flowchart of a distance detection device.

FIGS. 4A and 4B are explanatory diagrams of linearity characteristics, wherein FIG. 4A is a diagram illustrating a diffuse reflection object, FIG. 4B is a diagram illustrating a regular reflection object, and FIG.

FIGS. 5A to 5C are examples of linearity characteristics of materials 1 to 3. FIG.

FIG. 6 is an explanatory diagram of an example of a correction table.

FIGS. 7A to 7C are explanatory diagrams of examples of video waveforms of materials 1 to 3, respectively.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 object 2 light source 4 reflected light 5 video signal 6 imaging sensor unit 7 distance detection unit 8 determination unit 9 correction table 10 correction unit 11 photodetector 12 controller

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] October 24, 1996

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] All figures

[Correction method] Change

[Correction contents]

FIG. 4

FIG. 6

FIG.

FIG. 2

FIG. 5

FIG. 7

FIG. 3

Claims (4)

[Claims] 1. An optical distance detector for irradiating an object with light and detecting a distance to the object based on reflected light from the object, wherein a reflected light image of the object including a plurality of types of members is captured. Imaging means for obtaining a video signal by means of: a distance detecting means for detecting a distance to an imaging part of an object based on the obtained video signal; and a member type of the imaging part based on characteristics of the obtained video signal waveform. A distance detection device with a measurement member correction, comprising: a determination unit; and a correction unit that corrects the detection distance based on the determined member type. 2. The distance detecting apparatus according to claim 1, wherein the determination of the type of the member is performed by analyzing the height, width, and frequency of the video signal waveform. 3. The correction means has a correction table corresponding to the type of each member of the object, and switches between the correction tables according to the determined member type. 3. The distance detecting device according to claim 1, wherein the measuring member is corrected. 4. The distance detecting device with a measuring member correction according to claim 3, wherein the type of the member of the correction table is in accordance with the presence or absence of a metal material, a resin material, or a surface treatment.