JPS63222202A - Apparatus for measuring distance and angle of inclination - Google Patents

Abstract

PURPOSE:To perform measurement with good accuracy without receiving the obstruction of other optical system, by arranging three or more sets of sensor pairs detecting the reflected lights obtained by projecting the light signals from a light sources on a surface to be measured in a dispersed state and using light signals of different kinds in the sensor pairs. CONSTITUTION:The light signals different in a wavelength from light sources 3-5 arranged to a sensor part 1 in a dispersed state are projected on a surface 2 to be measured through projection lenses 6-8 under the control of a light emission controller part 9 to form images at light projecting positions 9-11. The light signals reflected from the light projecting positions 9-11 are formed into images on light receiving elements 15-17 through filters 22-24 and light receiving lenses 12, 14. The light receiving elements 15-17 are preliminarily inclined to take a measure with respect to the variation in the distances between the light projecting positions 9-11 and the light receiving lenses 12-14. The outputs of the light receiving elements 15-17 are operated by a light projecting distance operator 20 and a distance/angle-of- inclination operator 21 to detect the distance and angle of inclination between the surface 2 to be measured and the sensor part 1. By this method, the obstruction from other optical system is excluded and measuring accuracy is enhanced.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is an optical system suitable for non-contact detection of the relative distance between a processing tool such as a welding torch and an object to be measured, as well as its position and shape. Related to target distance/inclination angle measuring device.

[Conventional technology]

Optical detection is a typical method for non-contact detection of the relative distance between various processing devices and the workpiece (object to be measured) and the posture of the workpiece (inclination angle, shape, etc.) It is true. As such a means, the
The one described in Publication No. 843 is known.

This conventional technology irradiates three or more spot lights with a constant diffusion angle onto the work surface (surface to be measured), connects the images to the focal plane of the image sensor, and establishes the relative positional relationship between the work surface and the image sensor. By detecting the position change of the spot light image in the focal plane of the image sensor with respect to the change in .

This is to calculate the inclination angle of the work surface with respect to the image sensor optical axis.

[Problem that the invention seeks to solve]

The conventional angle detection method described above detects the inclination angle of the work surface with respect to the detector when the reflected light from the work surface contains a large amount of specular reflection component (for example, when the specular reflection component is strong in a work such as an iron plate). There is also the problem that it is difficult to accurately measure relative distances. In other words, it is geometrically impossible to focus multiple light spots on the work surface and form images on the same light-receiving surface, and some spot light images will be out of focus. .

At the same time, if a specular reflection component is included, the reflected light in a certain direction may be extremely strong, and the light spot will not be incident on the entire surface of the receiving lens with a uniform amount of light, resulting in the spot light This is because the light quantity center of gravity of the image is decentered, and the measured outputs of distance and inclination angle include errors.

An object of the present invention is to make the light from each light source a different signal light, so that each light receiving system can receive the reflected signal of the paired light projecting system without being influenced by other light projecting systems. Its purpose is to measure distances and angles of inclination.

[Means for solving problems]

The problem described above is that three or more pairs of a light projecting system having a light source that projects an optical signal onto the surface to be measured and a light receiving system having a light receiving element that receives the reflected light signal from the 2InIn slope are arranged in a distributed manner. each pair of light sources emits different optical signals;
a sensor unit comprising means for selectively outputting information on the reflected light signals of the light emitting systems in which each pair of the light receiving systems is paired; a light projection distance calculator that calculates a relative distance between a predetermined position and a light projection position on the measurement target surface; and a light projection distance calculator that calculates a relative distance between a predetermined position and a light projection position on the measurement target surface; This problem is solved by a distance/inclination angle measuring device equipped with a distance/inclination angle calculator that calculates the average relative distance and inclination angle.

[Effect]

According to the above configuration of the present invention, each light emitting system emits a unique optical signal onto the surface to be measured, and from among these reflected light signals, each light receiving system selects the reflected light signal of the corresponding light emitting system. Based on the information, the projection distance calculator calculates the relative position between the predetermined position of each pair of projection systems and the projection position on the surface to be measured, and calculates the calculated value. Based on this, the distance/inclination calculator calculates the average relative distance and inclination angle between the predetermined plane of the sensor section and the surface to be measured.

〔Example〕

Embodiments relating to the present invention will be described using FIGS. 1 to 6.

Figures 1 and 2 are block diagrams of the device according to the present invention. Figure 1 shows a case in which light with different wavelengths is used as an optical signal, and Figure 2 shows a case in which different modulated waves are used as a signal wave. This device can be roughly divided into a sensor section 1 that emits an optical signal onto a measurement target surface 2, receives the reflected light signal, and outputs it as a detection signal, and a controller section 18.
The controller section 18 includes a light emission control section 19 that controls the sensor section 1, and a light emitting control section 19 that controls the sensor section 1 of each light projection system based on the detected value (in this embodiment, the light projection lens 6, 7, 8). A light projection distance calculator 20 calculates the relative distance between the center position of A plane defined by the value and the predetermined position of the sensor unit 1 of each light projection system (in this embodiment, each light projection lens 6.7.
It consists of a distance/inclination angle calculator that calculates the inclination angle between the plane (including the center point of 8) and the surface to be measured.

The sensor section 1 includes three or more pairs of light emitting systems and light receiving systems. In this example, there are three pairs. That is,
Each light projection system includes a light source 3 and a light projection lens 6, a light source 4 and a light projection lens 7, and a light source 5 and a light projection lens 8. Each light receiving system includes a light receiving element 15, a filter 22, a light receiving lens 12, a light receiving element 16. Filter 23, light receiving lens 13, and light receiving element 17. It consists of a filter 24 and a light receiving lens 14. Among these, the light emitting system of the light source 3 and the light receiving system of the light receiving element 15 correspond to each other as a pair, and similarly, the light emitting system of the light source 4 and the light receiving system of the light receiving element 16 correspond to the light emitting system of the light source 5. The light receiving systems of the light receiving elements 17 each form a pair. The arrangement relationship between each light emitting system and the light receiving system is such that they mutually form a triangle as shown in FIG. 3 when viewed from above, and when viewed from the front, each light source 3 4.5 is the same height position, and each of the light receiving elements 15, 16, and 17 is also set at the same height position, but it is not necessary to limit it to the same height position.

As a light source, an LED or various laser light emitting sources can be used, and although the number of light sources is three in this embodiment, there is no need to limit it to this, and three or more may be used. The mutual relationship may be parallel, divergent, or convergent; however, in order to simplify the explanation, in this embodiment, it is assumed that the three projected beams are parallel to each other.

The light receiving elements 15, 16, and 17 are semiconductor-dimensional optical position detection elements (PSD: Po5ition 5en).
sitiveDetector) is suitable. In other words, when compared with other types of light receiving elements, CCD (
This is because the response speed of the charged coupled device is delayed by the scanning time, and the photodiode array is inferior in terms of optical image resolution. On the other hand, PSD is suitable because it has a high-speed response (about 10 μS) and can perform measurements with a short sampling period (for example, 5 KHz).

The light receiving elements 15, 16, and 17 are arranged in an inclined manner with respect to the direction of incidence of one reflected light signal, as shown in FIGS. 1 to 5, respectively. This is due to the following reason. That is, each optical signal reflected on the work surface 2 passes through each of the light receiving lenses 12, 13, 14, and is irradiated onto the light receiving surface of each light receiving element 15, 16.
When the position of the optical signal changes (descends in FIG. 5) as shown by the solid line in FIG. (in Figure 5, it changes to the left). In this case, in order to always form a focused optical image of the optical signal on each of the light receiving surfaces of the light receiving elements 15, 16, 17 in response to changes in the position of the work surface 2, the light emitting position must be 9° 10°. .11 is the light receiving lens 12, 13, 1
4, the imaging position approaches the light-receiving lens, so it is appropriate to arrange it at an angle as shown. For example, regarding the light receiving element 17, the degree of the inclination is as follows:
The intersection point between the extending direction line of the light receiving lens 14 surface and the extending direction line of the light receiving element 17 is set so as to be located on the optical axis of the projected signal light passing through the lens center of the projected lens 8. This also applies to the other light receiving elements 15 and 17, so the explanation will be omitted.

An embodiment in which lights of different wavelengths are used as optical signals will be described with reference to FIG.

The wavelength of each light from light sources 3 and 4.5 is 750 nm, 7
80 nm and 810 nm, and when the respective laser diodes emit light, the corresponding light receiving lenses 12, 13, 1
Optical band filters 22, 23 .
24, as shown in the transmittance shown on the right side of FIG. 6, only the light of the wavelength emitted by each corresponding light source 3°4.5 passes through the corresponding light receiving lens 12, 13, 14, and passes through the corresponding light receiving element 15, 16. Imaged on 17.

Next, an embodiment in which modulated light modulated at different frequencies is used as an optical signal will be described with reference to FIG.

By means of a transmitting circuit, an example of which is shown in the lower left of Fig. 7.

5KHz for light having a predetermined wavelength as a carrier wave.

Signal waves of 10 KHz and 15 KHz are generated, and modulated light modulated by the signals is emitted from light sources 3 and 4.5, respectively. Each light receiving lens 12, 13.degree. 14 and each light receiving element 15, 16, 17 of the light receiving system receives not only the modulated light of each pair of light sources but also the modulated light of other pairs. However, the light receiving element 15
, 16.17 are input to the respective electric band filters 22, 23.24, the outputs can select the modulated light of the light source 3.4.5 corresponding to the light receiving system. Electric band filter 22 for modulated light of each frequency
．． The passage rate of 23.24 is shown in the upper right corner of FIG. 7, and an example of this filter circuit is shown in the lower right corner of the figure.

As described above, according to the present invention, each light receiving system can output only the optical signal of the corresponding light projecting system, and is not interfered with by other light projecting systems.

The controller section 18 includes a light emission control section 19 that generates light of different wavelengths or modulated waves that are different from each other, a projection distance calculator 20, and a distance/inclination angle calculator 21.

In the embodiment shown in FIG. 6, the light emission control unit 19 shown in FIG.
In the embodiment shown in FIG.
15KI (z signal wave is generated, laser diode 3,
From 4.5, modulated light is generated and the amount of light is controlled.

The light projection distance calculator 20 calculates the distance between each light projection position 119, 10.11 and the center position of the light projection lens 6.7.8 of each light projection system based on the detection signal output from each light receiving system. Relative distances (hereinafter referred to as light projection distances) 02-D,, D, are calculated. Here, a method of calculating the light projection distance, D, D, will be explained. In order to simplify the explanation, only the light projection distance D3 between the light source 5 and the light projection position 11 will be described in correspondence with FIG.

In FIG. 5, the relative distance between the lens center point of the light projecting lens 8 and the light projecting position 11 on the work surface 2 is defined as D3, and the distance between the lens center point of the light projecting lens 8 and the lens center point of the light receiving lens 14 is The distance L3 is constant, and the angle between the projected signal light and the reflected signal light is 03. Now, when the height position of the work surface 2 changes from the dotted line position to the solid line position, the straight line connecting the light emitting position 11 and the lens center of the light receiving lens 14 at the solid line position (that is, the reflected beam) changes as shown by the solid line. , the position of the signal light image on the light receiving surface of the light receiving element 17 changes. , the output signal S3 of the light receiving element 17 at this time is at an angle θ
It is expressed as a function of , 53=f (0,) Angle θ, is °・03=f″″1(sa)...
...(1). Then, the projection distance is D, =□ tan O.

It is expressed as

Therefore, the light projection distance calculator 20 calculates the light projection distance D3 using the above equation (2). Other projection distances,
The same applies to ,D.

Next, the distance/inclination angle calculator 21 calculates each light projection distance calculated value D1. The relative distance between the position of the sensor section 1 and the work surface 2 and the inclination angle of the work surface 2 with respect to a predetermined plane of the sensor section 1 are calculated based on D, , D3. Here, the calculation method will be explained.

Referring to FIG. 8, the sensor unit 1 has a first orthogonal coordinate system ox
Set yz. The predetermined plane is an XY plane. The origin 0 of the first coordinate system is placed at the center between the light sources 3 and 5, and the direction from the origin 0 to the light source 4 is the X axis.

The direction of the light source 5 is defined as the Y axis, and the direction perpendicular to these X and Y axes is defined as the Z axis. In this case, it is assumed that the light sources 3, 4.5 are located at each vertex of an isosceles triangle having a height b and whose base is a length a, which is a line connecting the light sources 3 and 5.

Next, the point that intersects (collides with) the work surface 2 (here, the work surface is assumed to be a plane passing through the light projection positions 9, 10, and 11) in the negative direction of the Z-axis is defined as the origin 0', and this Origin 0
The axes that pass through ' and are parallel to the X and Y axes are X' and Y', respectively.
The second orthogonal coordinate system 0 has the Z′ axis on the Z axis.
Set '-X'Y'2'.

Here, D is the distance between the origin 0 and 0' (the average distance between Dl), and θ8 is the angle θ7 between the X' axis and the straight line connecting the origin O' and the light projection position 10 is the distance between the Y' axis and the origin 0. ' - defined as the angle formed by the straight line connecting the light projection position 11.

DveX+07 is calculated using the following equations (3) to (5).

b　　　　　　2b Further, the average relative distance DH is expressed by the following formula.

DM=-(D1+D2+D,)...
(6) That is, the distance/inclination angle calculator 21 executes the calculations of the above equations (3) to (6).

〔Effect of the invention〕

According to the present invention, by making the light of each light source a different signal light, each light receiving system can output a detection signal corresponding to the optical signal of the corresponding light projecting system, so that the light of the other light projecting system can be output. The average relative distance and inclination angle between the predetermined plane of the sensor section and the surface to be measured can be calculated with high accuracy without being affected.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a block diagram showing another embodiment of the invention, and Fig. 3 is a plan view showing the arrangement relationship of each element of the light emitting/receiving system in the sensor section. Figure 4 is an elevational view of Figure 3, Figure 5 is an explanatory diagram of the method of calculating the projection distance, Figure 6 is an illustration of the light emitting/receiving system using optical signals of different wavelengths, and Figure 7 is FIG. 8 is an explanatory diagram of a light projection/reception system using optical signals with different modulation frequencies, and FIG. 8 is an explanatory diagram of a method of calculating distance and inclination angle. 1...Sensor part, 2...Measurement target surface (work surface), 3.4.5...Light source, 6.7.8...Light projection lens, 9.10.11...Projection Light position, 12.13.14... Light receiving lens, 15.16, 17... Light receiving element, 18... Controller section, 19... Light emission control section, 20... Light projection distance calculator, 21... Distance/inclination angle calculator, 22.23, 24... Filter. Agent Patent Attorney Tatsu Unuma Figure 1 Figure 3 Figure 4 Figure 5 Figure 8 Figure 7 7° Trust 3

Claims (5)

[Claims] (1) Three or more pairs of a light projection system having a light source that projects an optical signal onto the surface to be measured and a light receiving system having a light receiving element that receives the reflected light signal from the surface to be measured are arranged in a distributed manner, The light sources of each pair emit different optical signals, and the light receiving system of each pair includes a sensor unit having means for selectively outputting information of the reflected light signals of the light emitting systems that are paired with each other. a light projection distance calculator that calculates a relative distance between a predetermined position of the light projection system and a light projection position on the surface to be measured based on the selected output of the light receiving system; A distance/inclination angle measuring device comprising: a distance/inclination angle calculator that calculates an average relative distance and inclination angle between a predetermined plane of the sensor section and the measurement target surface based on a calculated value. (2) The apparatus according to claim 1, wherein the mutually different optical signals are lights having different wavelengths. (3) The apparatus according to claim 1, wherein the mutually different optical signals are mutually different modulated lights. (4) The means for selectively outputting is an optical band filter that is provided in front of the light receiving lens of each light receiving system and selectively passes the reflected light signal of the light projecting system paired with the light receiving system. An apparatus according to claim 1 or 2, characterized in that: (5) The means for selectively outputting is provided subsequent to the light receiving element, and among the outputs of the light receiving element, output is based on the reflected light signal of the light projecting system paired with the light receiving system of the light receiving element. 4. The device according to claim 1, wherein the device is an electrical band filter that selectively outputs.