JPS60209105A - Displacement measuring instrument - Google Patents

Abstract

PURPOSE:To obtain accurately two-dimensional information corresponding to the shape of distance information on plural points, i.e. an object of measurement through single-time measurement by irradiating the object of measurement with light from a linear light source and photodetecting reflected light in two dimensions by an image sensor. CONSTITUTION:The displace measuring device consists of the linear light source 1 which irradiates the object X of measurement with beam light in a specific direction and the image sensor 3 which photodetects reflected light from the object X through a photodetection lens 2 at a specific angle theta0 to the irradiation direction of the beam light. Then, the light source 1 irradiates the object with the linear beam light which spreads within a specific range A and the sensor 3 consists of plural photodetecting elements S in two dimensions in its photodetection direction and slants at a specific angle thetaalpha to the image formation point surface of the lens 2. Consequently, a controller calculates the distance to the object X of measurement and information on its shape by triangulation on the basis of detection results of coordinates (i, j) of a elements S corresponding to a reflected light photodetection position on the sensor 3.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a displacement measuring device capable of simultaneously obtaining the distance to a measurement target and its shape, and more specifically, a light source that irradiates a beam of light toward the measurement target from a predetermined direction; an image sensor that receives reflected light from the measurement target from a direction at a predetermined angle with respect to the irradiation direction of the beam light through a light receiving lens; The present invention relates to a displacement measuring device that measures information on the distance or shape of the object to be measured using the principle of triangulation.

Conventionally, this type of displacement measuring device was disclosed in Japanese Patent Application No. 58-3.
No. 78208 and Japanese Patent Application No. 58-201526, etc., the present applicant has already proposed a t-dimensional image sensor, and a radar light is used as a light source to irradiate a measurement object with a spot light. There is a one-dimensional displacement measuring device that measures distance using the principle of triangulation based on the detection result of the position of the reflected light received from the target, but such a displacement measuring device is capable of performing so-called spot ranging. However, it has been impossible to obtain multiple pieces of distance information corresponding to the shape of the measurement target at once.

Therefore, in order to obtain information corresponding to the shape, it is necessary to repeatedly measure distances at multiple points by moving the displacement measuring device or the object to be measured. The drawback is that it takes time to obtain accurate shape information.

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to provide a displacement measuring device that can accurately obtain distance information of a plurality of points, that is, two-dimensional information corresponding to the shape of the object to be measured, through one measurement. Our goal is to provide the following.

In order to achieve the first object, the displacement measuring device according to the present invention emits a linear beam of light that spreads over a predetermined range from the light source, and the image sensor has a plurality of light receiving elements aligned in the light receiving direction. They are arranged in three dimensions and are arranged at a predetermined angle with respect to the image-forming point plane of the light receiving lens, and are configured to be arranged at respective positions corresponding to the reflected light receiving positions on the image sensor.

Due to the above structure, the following excellent effects have been achieved.

In other words, the image sensor receives the reflected light emitted from the line light source and reflected by the object to be measured in a λ-dimensional manner, and measures the distance from the coordinate position of each light receiving element corresponding to the receiving position, so the image sensor detects the reflected light. At the same time, distance measurement data corresponding to not only the distance of the object within the light-receiving range but also its shape can be obtained. In addition, since the light-receiving surface of the image centimeter is tilted at a predetermined angle with respect to the image-forming point of the light-receiving lens, each light-receiving element can be positioned at the actual image-forming position to accommodate changes in the reflection position due to movement of the measurement target, etc. This allows the reflected light to be received accurately.

Therefore, it has become possible to simultaneously obtain information on accurate distances and shapes of multiple points.

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIGS.
a laser light source Ill as a linear light source that irradiates a linear beam of light that spreads in a predetermined range in the horizontal direction toward K;
The light source Ill is placed at a predetermined distance (-) in the vertical direction, and is placed at a predetermined angle (θρ) from the measurement target (
3) is provided with an image sensor (3) having the configuration described later that receives the reflected light from the light receiving lens (2).
Based on the principle of triangulation, a predetermined distance (La) is determined based on the reflected light receiving position (range) of the image sensor (3).
b) Displacement measurement that simultaneously measures the distances @ (Lj) of multiple points (i) to the measurement target (Xl) in the range (range indicated by A in Figure 1), that is, the visual field of the image sensor (3) Configure the device.

The image sensor (3) is arranged tilted at a predetermined angle (θα) with respect to the imaging point of the light receiving lens (2), and the image sensor (3) is tilted at a predetermined angle (θα) with respect to the imaging point of the light receiving lens (2). This allows the reflected light to be accurately received even when the light is reflected.

Moreover, as shown in FIG. 2, the image sensor (3)
A plurality of light receiving elements (S) are two-dimensionally arranged at predetermined intervals, and are composed of so-called CCD or MOS type image pickup elements. The configuration of the control device (4) that detects the light receiving position of the image sensor (3) having the above configuration and converts it into measurement distance information is used below. This will be explained based on the block diagram shown in FIG. 3 and the time chart shown in FIG. 4.

The control device (4) is composed of each signal processing section described below.

(5) is a light reception signal of the reflected light of each light receiving element tSl which scans the image sensor (3) with a clock signal (Cpρ described later) and synchronizes it with a vertical synchronization signal 5t (VD) and a horizontal synchronization signal e (HD). This is a low-pass filter that converts a step-like output video signal (Pl) into a continuous curved video signal 8 (powder), and is provided to increase the resolution of measurement distance.

(6) is a subtracter that removes the noise component by subtracting the reference voltage (■) output from the reference voltage generating section (7) from the output signal (-) of the filter (5).

(7) is a reference voltage generation unit that sets a reference voltage (VO), which is a threshold for removing noise components from the output signal (P2) of the filter (6), and outputs it to the subtracter (6). be.

(3) is a high-speed A/D converter that converts the output (~) of the subtracter (6) into a digital signal.

(9) is a maximum value circuit that extracts the maximum value (Vp) of the video signal (P, ) from the output signal of the A/D converter (3), and its operation is based on the maximum value ffp). Mode (mode l) that outputs directly to the color converter (12) and maximum value memo below! It is configured such that a mode (mode 2) in which the data is temporarily stored in J (It) and then output indirectly is selectable.

(toaI/i,, vertical blank signal 9 (V, BL) and horizontal blank signal $ (
A vertical scanning unit counts the number of horizontal scanning lines under measurement for each vertical blank signal (V, BL) in synchronization with the light receiving element (H, BL) on the image sensor (3).
It is configured to output data (~) corresponding to the vertical coordinate position (i) of Si, j).

(11) is a maximum value memory that stores the maximum value (Vp) output from the maximum value circuit (9) using the count value of the vertical scanning kakunta (101) as an address in the case of mode 2; At the same time as storing the maximum detection value, see D below.
It is configured to output the previous detected maximum value (Vp) to the /A converter (I2).

0 is a D/A i converter that converts the digital value (maximum value fVp) into an analog value 8.

θ4 is for attenuating the D/A converter (maximum value ffp converted into an analog signal by the signal) at a predetermined ratio and binarizing the output signal (P3) of the subtracter (6). This is an attenuator that calculates the threshold voltage (SL).

(14 compares the output signal (P3) of the subtracter (6) with the threshold voltage (SL) output from the attenuator H, and determines whether the output signal (the powder level is above the threshold voltage (SL) This is a comparator that converts a certain interval into a value conversion signal !'+(P,) where @H level.

α is a waveform shaping circuit that removes noise components from the received light @ St (P,) which is converted into a value and output from the comparator 04, and separates and outputs the signal into two signals (~, In addition, these two signals (P5)
, (R) is a timing signal for controlling the operation of the multiplexer (described later).

(161 is the output signal (gradient) of the waveform shaping circuit.

(Pρ and clock signals (Cp2) and (Cps) supplied from the branch unit (181) to be described later) to the image sensor (3
) for detecting the horizontal light receiving position (l).
This counting clock (CN) is supplied from the later-described branching unit (I barrel) from the rising edge of the horizontal blank signal (H, BL) to the rising edge of the co-valued signal (P4). The frequency of the clock signal (Cpρ) is f.×n, and the co-valued signal (P,) is 1H.
In the interval where the frequency is fo Xrv'2, the clock signal (Cp,) is outputted and then stopped.

(I7) is a source clock (CpQ
) is a crystal oscillator (hereinafter abbreviated as O20) that outputs.

all is a predetermined frequency (fo), (foX
n), (foXa/2) operation clock signal (C
This is a branching unit that outputs (CpJ, (C negative)).

By counting the counting clock (CN), the light reception signal (~
Detects the center of the image sensor (NA in FIG. 4), that is, the horizontal coordinate position (j) of the light receiving element (St, j) that receives the reflected light on the image sensor (3). It is a horizontal scanning high-speed force tank.

(Company) uses the output count value (j) of the horizontal scanning high-speed kakunta Q9) for all output values (1) K of the vertical scanning kakunta (10) as an address, and calculates the measurement target (Xi
The memory 1 stores in advance a table of distances (Lj) corresponding to count values (j) for all output values (i) up to the present time.

(211 is the kakunt value (powder, that is, the vertical coordinate of the light receiving element ts+) of the vertical scanning katank
The memory 2 stores the distance correction data (Lj) corresponding to i). Note that this correction data (Lj) is necessary because of the focus error of the light receiving lens (2) and the image sensor (3). This is because it is necessary to correct the distance conversion according to the interval error of the light receiving element rows, etc.

□□□ is the distance value (Lj
) and the correction data (
This is an adder/subtracter that adds/subtracts Lj and corrects it to an accurate distance value.

(b) is the distance value (Lj
) and the output of the adder/subtractor, and if a measurement error that outputs a distance value (Lj) outside the measurement range or an arithmetic error of the adder/subtractor occurs, a 1 measurement error signal (E
rr) to the outside.

(Incorporated) is a scanning line number data output unit for outputting the vertical scanning output (~) to the outside as scanning line data (Syt).

(to) is a distance data output unit for outputting the distance value (Lj) corresponding to the scanning line number data (Syl) to the outside.

The operation mode of the maximum value circuit (9) (mode 1,
2), the control signal of each signal 5J-processing unit is changed, and each signal (Syρ, (Lj
), (Err) transmission timing, that is, the read strobe signal '+(S
This is a programmable system controller unit that outputs yρ.

(ii) η is a system reset unit that outputs a power reset signal and an initialization signal for starting measurement to each signal processing unit described above.

Each light receiving element (S) on the image sensor (3)
i, j) in the horizontal direction (IK-pixel by pixel) and move the scanning position in the vertical direction (f) by one pixel to obtain the reflected light receiving position, that is, the measurement target ( Distance data (Li
*j) izN data and scanning line number data (SyL
) is examined.

Note that the maximum value circuit (9) has a maximum value memo 'J full
), and its output maximum value (Vp) is set as the maximum value (PLl) of the received light signal during the previous horizontal scanning (ji) in the previous mode, that is, the threshold level of the current time (j). (sLL) and operates in mode 2 to determine the maximum value of the light-receiving signal (P
It operates to determine the current threshold level (SLO) using LO as its maximum output value (Vp).

Further, the light source (1) can be configured by spreading the output laser light using a He-Ne radar or the like into a predetermined range with an optical system such as a lens, or by scanning it, thereby essentially forming a line light source. In that case, even if it is not a flat light as shown in the first factor, if it is possible to irradiate within the distance measurement range (4), a linear light beam that spreads out in a fan shape from the light source position is irradiated. It may also be a light source. Furthermore, any light source may be used as long as it can provide sufficient contrast to the measurement target (Xl) with respect to the surrounding brightness.

[Brief explanation of the drawing]

FIGS. 1(A) and 1(B) are schematic diagrams showing the configuration of a displacement measuring device according to the present invention, in which FIG. 1(A) is a plan view and FIG.
B) is a side view, FIG. 2 is an enlarged plan view showing the structure of the image sensor, FIG. 3 is a block diagram showing the structure of the control device, and FIG. 4 is a time chart showing its operation. +11... Line light source, (2)... Middle light receiving area, (3) Old image sensor, (S) Old... Light receiving element, (3)...・Measurement target, prisoner...predetermined range, (i, j)...coordinates, (Lj)...
...Distance, (θρ, (θα)...Predetermined angle. Agent: Osamu Kitamura, patent attorney

Claims (1)

[Claims] A measuring object (light source +1 that emits a beam of light toward , an image sensor (3) that receives light through lenses (2), and determines the distance or shape of the object to be measured (Xi) by the principle of triangulation based on the detection result of the position of the reflected light received on the image sensor (3). This is a displacement measuring device that measures information on a displacement measuring device, in which the light source 11+ irradiates a linear beam of light that spreads over a predetermined range (4), and the image sensor (3) has a plurality of light beams in the light receiving direction. The light-receiving elements +81 are arranged two-dimensionally and are tilted at a predetermined angle (θα) with respect to the imaging point plane of the light-receiving lens (2), so as to correspond to the reflected light receiving position on the image sensor (3). Displacement measurement characterized in that it is configured to simultaneously obtain information on the distance (Lj) to the measurement target and its shape based on the coordinate (i, j) position detection result of each light receiving element (S). Device.