JPH03248005A - Configuration measuring apparatus - Google Patents

Abstract

PURPOSE:To measure the configuration of the surface of a body at a high speed by specifying the space coordinates of the surface of the body to be measured based on the identifying data of slit light and position data. CONSTITUTION:Laser light forms the slit light through a lens system 2. The light is projected on a body to be measured 4 through a polygon mirror 3. When a reset signal 6 which is outputted when the slit light passes a reference position is supplied, an identified data generator 24 counts clock pulses phi0 and outputs identified data Q. The reflected light from the surface of the body is received with an image sensing device 9. The slit-shaped optical image of the surface corresponding to the slit light n(t) is formed on a photosensor group11 forming an image sensing element 10. A scanning-signal generator 22 into which the signal 6 and the pulses phi0 are supplied is synchronized with the pulses phi0 and outputs pulses phi2. A position-data reading part 21 outputs the received-light-position data of the sensor group 11 as a signal S at the position of each deflection angle of the slit light. The data S and the data Q are stored in a memory 25 together. The contents in the memory 25 are matched after the end of the deflecting scanning of the slit light in a matching operation processing part 26. The data are converted into the space coordinates of the surface of the body 4.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a shape measuring device, in particular, to irradiate a light beam onto the surface of an object to be measured, and deflect and scan the light beam to obtain an optical image of the surface of the object to be measured. This invention relates to improvement of a non-contact shape measuring device for measuring the shape of an object.

[Conventional technology] Shape measurement of three-dimensional objects using optical systems is based on CAD/C.
It is expected to be applied in various fields such as AM, computer vision, robot eyes, measurement and analysis of biological and natural objects in fields such as medicine and fashion, and graphic design.

Shape measurement using conventional optical methods can be divided into several methods, and the stereo method is known as a representative method. According to this stereo method, images of an object to be measured are first captured from a plurality of viewing directions using a plurality of industrial cameras, and the shape of the object to be measured is extracted from the screen.

This method is based on the principle of binocular stereopsis, and the captured image data is captured as grayscale signal data over the entire imaging surface, and in order to extract only the necessary shape from this information, , corresponding point detection processing is unavoidable, and this requires various image processing, huge storage capacity, and long processing time, so it has not yet been realized as a high-speed and simple device. in a state.

Among other conventional methods, the optical cutting method is considered to be the most common and highly practical. In this optical cutting method, a spot-shaped or slit-shaped light beam is irradiated onto the object to be measured, and a video signal based on an optical image of the surface of the object to be measured corresponding to the light beam is input into a computer using an imaging device. ,
The spatial coordinates of the surface of the object to be measured are determined from the positional information of the optical image on the imaging surface obtained as a result of processing this information and the relative positional relationship between the light beam and the imaging device.

That is, according to the conventional optical cutting method, for example, a deflected and scanned light beam is irradiated onto the surface of the object to be measured (17P+), and an optical image of the surface of the object to be measured by this light beam is created by ITV.
A camera captures it into the computer in the form of a video signal.

Therefore, according to this conventional method, the position of the optical image on the surface of the object to be measured is specified by sequentially electrically scanning the entire imaging surface, and this is performed for each light beam being deflected and scanned. The shape of the three-dimensional object is measured from a large amount of data obtained in this way.

However, according to the conventional light sectioning method, as mentioned above, in order to detect and specify each point on the surface of the object to be measured, it is necessary to scan the entire imaging plane each time, and as a result, shape measurement The problem was that it took an extremely long time and real-time measurement was impossible. Normally, the time required to scan one screen is about 1/60 to 1/30 seconds in the case of a normal industrial television camera, for example, and in such a slow measurement operation, the shape of the object to be measured cannot be measured in real time. It has been almost impossible to perform measurements on moving objects.

In particular, in order to measure the shape of a three-dimensional object with practically sufficient resolution, the number of measurement points must be large. The beam deflection scanning itself had to be extremely slow, making it impossible to measure with sufficient resolution in real time.

In order to solve the above problems, in the past, Japanese Unexamined Patent Publication No. 62
A shape measuring method and device disclosed in No. 228106 has been proposed. According to this conventional device, the deflection angle of the slit light irradiated onto the object to be measured is used as the slit light identification information, and this is used as the position information of the received light. A matching calculation is performed, thereby providing improved shape measurement that does not require high-speed readout control.

[Problems to be Solved by the Invention] However, according to the conventional device described above, the structure of the image sensor becomes extremely complicated in order to simultaneously process light receiving position information and slit light identification information, and in particular, it is difficult to store image information. There is a problem in that the structure of the image sensor becomes complicated due to the storage capacity of the data storage unit and the data bus, and the device itself becomes large, making it difficult to mount it on an actual robot or the like.

The present invention has been made in view of the above-mentioned conventional problems, and its purpose is to improve the conventional device described above and separate the simultaneous processing of location information and identification information performed in the conventional device.
An object of the present invention is to provide a measuring device with a simple configuration.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a deflection irradiation device that deflects and scans a slit light toward the surface of an object to be measured under predetermined scanning control, and the deflection irradiation device. an identification information generator that outputs the deflection scanning angle of as slit light identification information;
[slit] - A group of photosensors arranged in one or two dimensions to form an optical image of the surface of the object to be measured by light, and a group of photosensors arranged corresponding to the group of photosensors to form an optical image. A CCD array that transfers the position of the photo sensor as position information, and a CCD array that reads and scans the CCD array at a higher speed than the deflection scanning of the slit light, and a position where an optical image is formed at each deflection scanning position of the slit light. A reading scanning unit that outputs information; and a calculation processing unit that calculates the shape of the object by comparing and calculating the position information of the photosensor stored in the CCD array and the slit light identification information of the identification information generator. It is characterized by

[Function] As described above, in the present invention, the slit light is irradiated onto the surface of the object to be measured while being deflected and scanned, the object surface is stroked by the slit light, and the object surface is moved on the imaging plane correspondingly. The position information on the imaging plane of the optical image of the surface of the object to be measured is
The light receiving position signals of a large number of mutually independent photosensors making up the imaging surface are detected. Then, this position information is transferred by a CCD array provided corresponding to the photosensor group, and the transfer and readout of this CCD array is performed at a higher speed than the deflection scanning of the slit light. Furthermore, the spatial coordinates of the surface of the object to be measured are specified from the slit light identification information corresponding to the deflection scanning angle of the slit light obtained from the identification information generator and the position information. As a result,
According to the present invention, it is possible to configure a measurement device that can sufficiently follow the object to be measured even when the slit light is scanned at high speed, so the present invention makes it possible to measure the surface shape of a three-dimensional object at high speed. .

[Example] Preferred embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows an example of a basic system configuration for measuring the surface shape of an object to be measured 4 using a light beam consisting of slit light.

A laser beam from a laser light source 1 is vertically expanded by a lens system 2 including a cylindrical lens to form a slit beam, which passes through a polygon mirror 3 and is irradiated onto the surface of an object to be measured 4. The slit light is deflected by sequentially changing its irradiation angle over time as shown in the figure by rotating the polygon mirror 3, and can stroke the surface of the object to be measured 4. The deflection angle of the slit light is uniquely determined by the rotation angle of the polygon mirror. Therefore, when identifying the slit light, the rotation angle of the polygon mirror may be directly measured, but the polygon mirror is usually controlled as a rotational motion at a constant angular velocity, and therefore the slit light is also deflected and scanned at a constant angular velocity ω. Therefore, the identification of slit light is
This can be realized by measuring the elapsed time t from the reset signal 6 output when light passes through a certain reference position. Since the identification information of the slit light beam deflected in this manner depends on the time t, the time t can be used as the identification information of the slit light for subsequent calculations. 1st v!
In J, the slit light is denoted as n (t).

In the present invention, the identification information is obtained as the output of the identification information generator 24 shown in FIG. The signal 6 is supplied to the reset manual R, and the identification information Q can be outputted by counting the clock pulse φ0 being supplied to the identification information generator 24 at this time.

In the example shown in FIG. 1, a photosensor 5, such as a phototransistor, is provided for detecting a reference position, and when the slit light crosses this photosensor 5, a reset signal 6 is output, and this signal generates identification information. The device 24 can be reset and the identification information of the slit light n (t) can be output as a count output Q (for example, a 10-bit parallel signal).

Therefore, according to the present invention, it is understood that the deflection angle of the slit light n (t) that strokes the surface of the object to be measured 4 is specified by the count output Q.

On the other hand, in this embodiment, the reflected light reflected from the surface of the object 4 is received by the imaging device 9, and the slit light n (
A slit-shaped optical image of the surface of the object to be measured 4 corresponding to time t) is formed on the photosensor group 11 forming the image sensor 10 of the imaging device 9 .

In the embodiment, photosensor group 1 of this image sensor 10
1 is configured as a one-dimensional or two-dimensional array of mutually independent photosensors arranged in alignment.

The image sensor 10 further includes a position information reading section 21, and this reading section 21 includes a CCD array, as will be described in detail later.
The signals received by the photosensor group 11 can be read out at a higher speed than the deflection scanning of the slit light, and as a result, the readout scanning of the position information reading section 21 forms an image on the surface of the photosensor group 11. A readout operation is performed with the optical image substantially stationary.

In order to control the reading of the position information reading section 21, a scanning signal generator 22 that is reset by the reset signal 6 and a counter 23 that counts the scanning signal are provided.

That is, the scanning signal generators 2, 2 each consist of a counter, and the clock pulse φ0 supplied to the above-mentioned identification information generator 24 is reset in synchronization with the identification information generator 24 by the reset signal 6, and its output is The pulse φ2 is obtained as follows.

This pulse φ2 is transmitted to the position information reading section 21 as described later.
On the other hand, the pulse φ2 is sent to the position information reading section 2 as an 8-bit parallel signal q by the counter 23.
1.

The signal q indicates the light receiving position on the photosensor group 11.

In this embodiment, the position information reading unit 21, the scanning signal generator 22, and the counter 23 are connected to the position information generator 20.
It consists of

As described above, at each deflection angle position of the slit light, the position information reading unit 21 outputs the light receiving position information of the photosensor group 11 as the signal S, and in the embodiment, this position information S is temporarily stored in the memory 25. , at the same time, the identification information Q from the identification information generator 24 is stored in this memory 25.
is memorized.

Therefore, the position information and identification information are recorded in the memory 25 at each deflection position of the slit light, and the reading of this position information and identification information and the corresponding storage of image information in the memory 25 are performed at each deflection position of the slit light. , and this is sequentially stored in the memory 25.

Then, after the deflection scanning of the slit light is completed, the contents of this memory 25 are subjected to a matching operation in a matching calculation processing section 26 and converted into surface space coordinates of the object to be measured 4.

That is, according to the present invention, both the identification information Q of the slit light n(1) and the position information S of the corresponding slit-shaped optical image can be detected in a separate manner, and the object 4 can be detected from the image information. It becomes possible to measure the surface shape of the surface at high speed.

In FIG. 1, a deflection irradiation device 1.2.3, an imaging device 9
If the relative positions of the image sensor 10 and the image sensor 10 are fixed, and the positional relationship is known in advance, the object 4 itself can be assumed to be stationary during the measurement period by performing deflection scanning at high speed according to the present invention. By performing this measurement at a speed sufficiently higher than the movement of the object 4 itself, even the moving object 4 can be regarded as stationary during the measurement period, and its shape can be measured. It is possible.

2 and 3 show that in the embodiment shown in FIG. 1, the surface shape of the object 4 can be identified from the identification information of the slit light and the position information of the optical image. That is, FIGS. 2 and 3 are based on the mirror reflection center M shown in FIG.
Slit light n reflected from (xm, yIIl, zy)
(t), a point P (X) on the surface of the object to be measured 4 illuminated by it.

Y, Z), and its optical image 1 (x, 0. zl
) on the xy plane (Fig. 2) and the
This is a projection onto a plane (Fig. 3).

In Figures 2 and 3, the solid line shows the situation in which a single slit beam is scanned onto the object to be measured using a single deflection irradiation device, and the chain line shows the situation in which a second deflection irradiation device is further placed at a different position. The object to be measured is deflected and scanned by the second slit light, and by using two deflection irradiation devices in this way, even if the object to be measured has unevenness, it is possible to measure the shape of the object by scanning with one slit light, which would be a shadow. This makes it possible to largely eliminate impossible surfaces.

In FIGS. 2 and 3, the origin of the orthogonal coordinate system (x, y, z) is, for example, the center O of the photosensor group 11, the X axis is horizontal and is set parallel to the photosensor group 11, and the y The axis is set to match the lens optical axis of the imaging bag E9,
Furthermore, the Z axis is set in the vertical direction.

Therefore, the coordinate value (X) of point P on the surface of object 4.

As shown, Y, Z) are specified by the slit light n(t) and the reflected light R(t), and the coordinate values of the lens position, the mirror position IM, and the rotational angular velocity ω of the slit light can be set as a total of Δp1 conditions. , the identification information of the slit light n (t) obtained as a measurement result, and the coordinate values (xi, Q, zi) of the optical image I of the point P can be obtained as follows.

0: Photo sensor group center (orthogonal coordinate system origin) 0 (0,
0, 0") L: Center of lens 9 on the imaging bag L (0, Vl, 0) M, M": Center of mirror reflection M (xm, y+n, zm).

M (xm, ym zm-)P, P-
: Point P (X, Y, Z) on the surface of the object to be measured.

P' (X-, Y-Zi 1.1-: Point 21 Optical image 1 of point P' (xi, yl, zi) I- (xi -yl-, zl'') P, D,: Reference of light beam Position (counter reset timing position) α, α Angle ω, ω that the Nislit light makes with the quasi-position of the slit light beam Rotation angular velocity of the Nislit light 1.1., Elapsed time after passing the Nislit light reference position Subscript xy, Subscript xz: As above, M, M=, P, P
I and I゛ Straight line representing the projection point on each point 2) Straight line IxzLxzPxz: 1 Therefore, I -1 (1), 10 (3) from (2) (2) (4) In the above formula, α is the product of the rotational angular velocity ω of the slit light and the identification information t, That is, α−ω・t, and as a result, equations (2) and (4) become Y
-tan(ωt+cro) (X-xIII)+y
m(5) − y, +xttan(′1“0)−(6) Therefore, the above (
3), (5), and (6), the three-dimensional coordinate values (X, Y.

Z) is the identification information of the slit light n (t), that is, the elapsed time t from the predetermined reset timing and the position information (xi, 0.z) of the optical image l on the photosensor group 11
It is understood that it is determined by both.

FIG. 4 shows a preferred embodiment of a scanning type image sensor that latches and stores positional information of the optical image on the photosensor group 11.

This scanning type image pickup device basically consists of a photosensor group 11 and a CCD array 30 shown in Figure 'M1.

In FIG. ff14, the photosensor group 11 is composed of a plurality of (MXN) phototransistors that are arranged and independent of each other.

Therefore, as is clear from the above description, the reflected light from the surface of the object 4 is received by the imaging device 9, and an optical image of the surface of the object 4 is formed on one of the elements of the photosensor group 11. Become.

The photoresponse output of this phototransistor is CC
It is sent to D array 30.

In FIG. 4, a CCD array 30 is provided corresponding to the photosensor group 11, and includes M CCD arrays 30 arranged horizontally in the figure, and each array is divided into N elements COD. has been done.

In the embodiment, the image sensor 10 has a two-dimensional (MXN) light-receiving surface, and the respective information of the CCD arrays 30 arranged in the horizontal direction are output from the CCD arrays 30 arranged in the vertical direction.
The data is sequentially converted vertically and read out by the CD array 20. transferred by pulse φ2, respectively,
Via the amplifier 31 (100), it is first supplied to the A register 32 as a storage trigger signal.

An 8-bit parallel signal q supplied from the counter 23 is supplied to the input terminal of the A register 32, and the signal value q when the amplifier output 200 is rHJ is
is stored in the A register 32.

Therefore, the signal transferred by the CCD array 30 includes position data of the photosensor 11 that received the light, and the q value 200 at that time is stored in the A register 32 at a timing corresponding to this position. As a result, the contents stored in the A register 32 indicate the light receiving position of the photosensor group 11 transferred by each CCD array 30, and it is understood that this is used as position information in the present invention.

In normal cases, as is clear from the above description, it is preferable that the received light image formed on the photosensor group 11 be limited to a single phototransistor, and therefore the contents stored in the A register 32 are also corresponds to a phototransistor.

Of course, if the received light image is blurred, etc., multiple phototransistors of the photosensor group 11 may receive light, but in such a case, the A register 32 stores the position information of one of them. I will do it.

The storage mode of the A register 32 is either a latch type or an update type.
When stored, this data is latched as a fixed value and no further input is accepted.

On the other hand, in the latter case, the A register 32 sequentially triggers the trigger 2
00 is accepted, and the final input is set as the stored value. Either type of register can be used in the present invention.

A characteristic feature of the present invention is that the CCD array 30
This is to perform the readout scanning at a higher speed than the deflection scanning of the slit light, and in FIG.
2 is formed from a driving pulse having a significantly higher frequency than the pulse φl which is the trigger input for the identification information Q.

As a result of the above, the data transfer from the CCD array 30 to the A register 32 in FIG. Transfer can be retained.

The position information transferred and held in the above manner is then transferred to the B registers 33 provided corresponding to the A registers 32.
When read, the data are sequentially sent to the memory 25.

In the embodiment, the device information S constituted by the B register 33 consists of an 8-bit parallel signal.

As described above, according to the present invention, the positional information of the optical image is detected separately from the identification information, and data is transferred by scanning the CCD array at high speed in a short time when the slit light is considered to be almost stationary. This can be achieved by doing this.

FIG. 5 shows the detection operation of the position information S shown in FIG. 4.

A new slit light deflection period is started by the generation of the reset signal 6, and the identification information generator 24 generates a clock pulse φ.
Generate an identification information pulse φ by counting 0,
The identification information Q is determined by counting this clock pulse φ1.
get.

Meanwhile, in synchronization with the reset signal 6, the scanning signal generator 2
0, a CCD drive pulse φ2 having a sufficiently higher frequency than the pulse φl is output, and the counter 23 outputs this pulse φ2.
is counted to obtain the signal q.

As mentioned above, the pulse φ2 is used as a readout drive pulse for the CCD array 30, and the parallel signal q, which repeatedly changes within each slit light deflection period in synchronization with this readout drive pulse φ2, is used as a count value of position information. used.

In the embodiment of FIG. 5, signal q is shown as a signal that counts 256 within the period of pulse φ1.

As described above, when the photosensor group 11 receives light, a slit optical signal indicated by reference numeral 100-1 in FIG. 5 is obtained,
This slit optical signal 100-1 is shown as a signal transferred from the CCD array 30 to the amplifier 31.

Note that FIG. 5 only shows the CCD array in the first row, and the other rows perform similar readout operations.

The waveform-shaped output of the amplifier 31 is indicated by 200-1, and at this time the contents of the A register 32 are latched.

That is, the contents of the A register 32 are determined by the signal q value when the signal 200-1 is output, and in this embodiment, it is the signal q (1 to 1) in the first row.

Similarly, data q(1-n) is sequentially stored in the A register 32 according to the position of the photosensor that receives light within each deflection period, that is, the slit light deflection period determined by the pulse φ1.

As mentioned above, all A register data in M rows are then -
The information is read out from each B register 33 at the same time, and in the embodiment, the contents of the register B are sequentially read out as position information S in synchronization with the pulse φl that determines the deflection position of the slit light.

Therefore, it is understood that this position information S is read out as data delayed by one period of the pulse φ1.

Of course, this delay will be adjusted when the memory 25 stores the position information S and the identification information Q in association with each other.

As described above, the memory 25 stores the position information S and the identification information Q separately while maintaining a synchronized relationship with each other, and performs a matching operation using the principle shown in FIG. 2.3 described above. Accordingly, the desired normal measurement calculation can be performed.

[Effects of the Invention] As explained above, according to the present invention, the surface of the object to be measured is stroked by the slit light, and a photo of the optical image of the surface of the object to be measured moves on the photosensor group accordingly. Position information on the sensor group can be detected in real time based on the light reception of each photosensor. On the other hand, the identification information of the slit light is obtained in synchronization with the deflection period of the slit light.
The shape of the object surface can be measured at high speed from the position information and identification information, and by scanning the object surface at high speed with slit light, extremely good shape measurement is possible even for moving objects. Become.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a measuring device showing a preferred embodiment of the object surface measurement method according to the present invention, FIG. 2.3 is an explanatory diagram showing the principle of the object surface measurement method according to FIG. 1, and FIG. FIG. 1 is an explanatory diagram showing a specific example of a suitable image sensor, and FIG. 5 is an explanatory diagram showing a position information reading operation of the image sensor shown in FIG. 4. 1 ... Laser source 3 ... Polygon mirror 4 ... Measured object 9 ... Imaging device 10 ... Image sensor 11 ... Photo sensor 20 ... Readout scanning section 24 ... Identification information Generator 26... Arithmetic processing unit 30... CCD array

Claims (1)

[Claims] (1) a deflection irradiation device that deflects and scans a slit beam toward the surface of an object to be measured under predetermined scanning control; and an identification information generator that outputs the deflection scanning angle of the deflection irradiation device as slit light identification information; A group of photosensors arranged in one or two dimensions to form an optical image of the surface of the object to be measured by the slit light, and a photo sensor provided corresponding to the group of photosensors and on which the optical image is formed. CC that transfers the sensor position as position information
D array; a readout scanning unit that reads out and scans the CCD array at a higher speed than the deflection scanning of the slit light and outputs positional information where an optical image is formed at each deflection scanning position of the slit light; and the CCD. 1. A shape measuring device comprising: a calculation processing unit that determines the shape of an object by comparing and calculating positional information of a photosensor stored in an array and slit light identification information of an identification information generator.