JP5410138B2 - Displacement sensor system and displacement sensor - Google Patents

Description

  The present invention relates to a displacement sensor for measuring the surface shape and the like of an object.

  Conventionally, a displacement sensor for measuring the surface shape and the like of an object is known (see Patent Document 1). This displacement sensor has a light projecting unit and a two-dimensional CCD, irradiates the surface of the object with linear light emitted from the light projecting unit, and receives the reflected light on the imaging surface of the two-dimensional CCD. Since the received light image formed on the imaging surface by the reflected light has a shape corresponding to the surface shape of the object, the surface shape of the object can be measured based on the light receiving position on the imaging surface.

JP 2007-139489 A

  However, the object whose surface shape or the like is to be measured is not limited to the one having a uniform reflectance over the entire surface, and there may be a plurality of regions having different reflectances and non-uniform reflectance. When trying to measure the surface shape or the like of such an object with non-uniform reflectivity using the above-described conventional displacement sensor, the amount of light received is saturated in the pixel that receives the reflected light from the region with high reflectivity. Thus, a pixel that receives reflected light from a region having a low reflectance has a problem that the surface shape or the like cannot be measured accurately because the amount of received light is small and noise resistance is low.

  The present invention has been completed based on the above circumstances, and an object of the present invention is to provide a displacement sensor system and a displacement sensor capable of measuring a surface shape or the like even with an object having non-uniform reflectance. There is a place to do.

  As means for achieving the above object, a displacement sensor system according to a first invention includes a light projecting unit that irradiates an object with linear light, and a line that is irradiated from the light projecting unit and reflected by the object. And a scanning line that intersects the received light image of the linear reflected light with a two-dimensional imaging device having an imaging surface capable of receiving the reflected light in the shape and a received light signal corresponding to the amount of light received by each pixel on the imaging surface A light receiving processing unit to be taken out every time, a region designating unit for designating a plurality of regions on the imaging surface in units of scanning lines, and individual light projecting / receiving sensitivity can be set corresponding to each region designated by the region designating unit A sensitivity setting unit and a light receiving signal of the scanning line in each region are extracted by the light receiving processing unit under the light projecting / receiving sensitivity corresponding to the region, and a detection process corresponding to the extracted light receiving signal is executed. A light reception control unit.

  According to the displacement sensor of the present invention, individual light projecting / receiving sensitivity can be set corresponding to different regions on the imaging surface, and the light receiving signal of the scanning line in each region is used as the light projecting / receiving sensitivity corresponding to the region. Can be taken out below. Therefore, even for an object with non-uniform reflectance, it is possible to measure the surface shape and the like by setting the light projecting / receiving sensitivity corresponding to the reflectance of each part on the imaging surface corresponding to each part. is there.

  A second invention is a displacement sensor system according to the first invention, wherein information on at least one of a light receiving position and a light receiving amount in each scanning line is obtained based on a display unit and a light receiving signal taken out by the light receiving processing unit. A display control unit to be displayed on the display unit and an operation unit are provided, and the region designating unit is configured to designate the region based on an operation by a user at the operation unit.

  According to this aspect of the invention, the display unit displays information related to the light receiving position and the amount of light received in each scanning line, so that the user can specify a region while viewing the display on the display unit.

  3rd invention is a displacement sensor system of 2nd invention, Comprising: The said display control part makes the said display part the light-receiving position based on the light reception signal taken out under the light projection / reception sensitivity corresponding to each said area | region to the said display part. Display graphics at the same time.

  According to the present invention, since the light receiving position based on the light receiving signal extracted under the light projecting / receiving sensitivity corresponding to each area is simultaneously displayed on the display unit, the user can determine whether the area designation is appropriate from the display. Is possible.

  A displacement sensor according to a fourth aspect of the present invention includes a light projecting unit that irradiates an object with linear light, and an imaging surface that can receive linear reflected light that is irradiated from the light projecting unit and reflected by the object. A two-dimensional imaging device, a light receiving processing unit that extracts a light receiving signal corresponding to the amount of light received by each pixel on the imaging surface for each scanning line that intersects the light receiving image of the linear reflected light, and on the imaging surface A sensitivity setting unit capable of setting individual light projecting / receiving sensitivity corresponding to each different area, and a light receiving signal of the scanning line in each region is extracted to the light receiving processing unit under the light projecting / receiving sensitivity corresponding to the region. And a light reception control unit that executes a detection process based on the extracted light reception signal.

5th invention is the displacement sensor of 4th invention, Comprising: The output part which externally outputs the information regarding at least one of the light reception position based on the light reception signal taken out with the light projection / reception sensitivity corresponding to every said area | region, and light reception amount Is provided.
According to the present invention, information on at least one of the light receiving position and the amount of received light based on the light receiving signal extracted with the light projecting / receiving sensitivity corresponding to each region can be transmitted to, for example, a host device.

  According to the present invention, it is possible to measure a surface shape or the like even with an object having a non-uniform reflectance.

1 is a schematic configuration diagram showing a part of a displacement sensor according to an embodiment of the present invention. Perspective view showing a part of the displacement sensor Schematic diagram showing the relationship between the received light image and the scanning line Block diagram showing electrical configuration of displacement sensor system Flow chart showing area designation processing Flow chart showing area-specific light emitting / receiving processing

An embodiment of the present invention will be described with reference to FIGS.
The displacement sensor system 1 of the present embodiment has a configuration in which a displacement sensor 10 (surface shape detector) and a controller 30 are connected to be communicable.

(Outline configuration of displacement sensor)
1 and 2 are a schematic configuration diagram and a perspective view showing a part of the displacement sensor 10.
As shown in FIG. 1, the displacement sensor 10 includes a laser light source 11 (an example of a light projecting unit) and a two-dimensional CCD 15 (an example of a two-dimensional image sensor), and transmits light emitted from the laser light source 11 to an insertion plate 12. The slit 12A is passed through to form a line, and the surface of the object W is irradiated with the slit 12A. The reflected light is received on the imaging surface 15A of the two-dimensional CCD 15.

  The received light image formed on the imaging surface 15A by the reflected light has the same shape (for example, linear shape) as the opening shape of the slit 12A if the surface of the object W (irradiated surface) is flat. On the other hand, when the surface of the object W is uneven, the object W has a shape following the unevenness (see FIG. 2). Therefore, the surface shape and the like of the object W can be measured based on the received light image (learning position) formed on the imaging surface 15A.

  As shown in FIG. 2, the object W has a plurality of portions having different reflectances, and the reflectance is nonuniform. Specifically, the object W is made of a main body W1 having an opening W1A formed on the upper surface and made of a low reflectance material (for example, black resin), and a high reflectance material (for example, a metal such as aluminum). And a lid W2 for closing the opening W1A.

(Relationship between received light image and scanning line)
FIG. 3 is a schematic diagram showing the relationship between the received light image and the scanning line L, and is also a diagram showing the display content of the display unit 31 described later.
The imaging surface 15A is composed of a plurality of pixels (light receiving elements) arranged in a matrix, and the scanning line along the thickness direction of the received light image (an example of the direction intersecting the received light image) Read every L. Then, for each pixel on the read scanning line L, for example, a light reception amount (light reception signal level) is compared to identify a pixel having a peak light reception amount, and its position (hereinafter referred to as a light reception position). Is detected.

  In this way, by performing the process of detecting the light receiving position on the scanning line L for each scanning line L, the surface shape, height difference, and the like of the portion irradiated with light can be measured. Moreover, the surface shape of the whole object W can also be measured by performing the same surface shape measurement for each part while relatively moving the object W and the displacement sensor 10.

(Electric configuration of displacement sensor system)
FIG. 4 is a block diagram showing an electrical configuration of the displacement sensor system 1.

1. Displacement sensor The displacement sensor 10 includes a first control unit 20 (an example of a light receiving control unit, a sensitivity setting unit, and an area designating unit) that controls the entire displacement sensor 10, a laser light source 11, a laser driving circuit 13, a two-dimensional CCD 15, A CCD drive circuit 17 (an example of a light receiving processing unit), a data processing unit 21 (an example of an output unit), and a memory 25 are provided.

  The laser drive circuit 13 is driven based on the operation signal Sa from the first control unit 20 to supply a drive current to the laser light source 11. Further, the operation signal Sa is a PWM signal, and the first control unit 20 can adjust the amount of drive current to increase or decrease by changing the duty ratio to change the amount of light emitted from the laser light source 11.

  The two-dimensional CCD 15 has an image pickup surface 15A in which light receiving elements are arranged in a matrix, and converts light incident on the image pickup surface 15A into an electric signal (light reception signal) having a level corresponding to the amount of light. The CCD drive circuit 17 sequentially reads the light reception signals output from the respective light receiving elements on the imaging surface 15A for each scanning line L. The scanning line L is set to extend in the vertical direction of the imaging surface 15A, and is orthogonal to the linear light reception image.

  The first control unit 20 causes the CCD drive circuit 17 to read a light reception signal from the two-dimensional CCD 15 while causing the laser light source 11 to perform a light projection operation via the laser drive circuit 13 (light projection / reception operation). Then, light reception position data for each scanning line L is externally output via the data processing unit 21 based on the light reception signal.

2. Controller The controller 30 includes a display unit 31, a second control unit 33 (an example of a display control unit), a data processing unit 35, and an operation unit 37. The data processing unit 35 can perform bidirectional data communication with the data processing unit 21 of the displacement sensor 10 by wire or wireless. The second control unit 33 performs display control of the display unit 31 and the like. For example, based on the light receiving position data received from the displacement sensor 10, each scanning line L on the imaging surface 15A as shown in FIG. A shape based on the light receiving position of each scanning line L is displayed on the display unit 31. The operation unit 37 is used by the user to perform various input operations.

(Area specification processing)
FIG. 5 is a flowchart showing the area specifying process. When the user instructs the execution of the area designation mode using the operation unit 37, the second control unit 33 instructs the first control unit 20 of the displacement sensor 10 to perform the execution, whereby the first control unit 20 performs the area designation process. Run. At this time, the first control unit 20 functions as an area designating unit.

  The first control unit 20 performs a light projecting / receiving operation (S1), and acquires light receiving position data of all the scanning lines L (S3). In the light projecting / receiving operation at this time, for example, the light projecting / receiving sensitivity (in this embodiment, the light projecting amount of the laser light source) is uniformly set to a predetermined initial value for all the scanning lines L. Then, the acquired light receiving position data is transmitted to the controller 30. Thereby, the second control unit 33 displays the shape of the received light image on the display unit 31 based on the light receiving position data (S5).

  Here, as described above, the reflectance of the object W is not uniform. For this reason, on the imaging surface 15A, the amount of received light is small and buried in noise in the region corresponding to the low reflectance main body W1, and the amount of received light is large and saturated in the region corresponding to the high reflectance lid W2. There is a risk of reaching. As a result, the light receiving position on each scanning line L cannot be detected accurately, and the display unit 31 may display the shape of the received light image that is inaccurate with respect to the actual shape of the object W. .

  However, even though the shape of the received light image is inaccurate, the user can generally visually recognize each region having a different reflectance from the shape of the received light image. Therefore, the user designates each region in units of scanning lines L by operating the operation unit 37 while looking at the display unit 31. In the example of FIG. 3, for example, three regions, a region of the scanning lines L1 to L5 (first region E1), a region of the scanning lines L6 to L16 (second region E2), and a region of L17 to L21 (third region E3). Is specified.

  When an area is designated by the user (S7: YES), the second control unit 33 transmits the area designation information (designation number of the scanning line L) to the displacement sensor 10. Then, the first control unit 20 stores the received area designation information in the memory 25 and ends this area designation process.

(Measurement process)
FIG. 6 is a flowchart showing the area-specific light emitting / receiving process.
When the user instructs execution of the measurement mode using the operation unit 37, the second control unit 33 transmits an execution command for the region-specific light projecting / receiving process to the displacement sensor 10. Then, the first control unit 20 executes the area-specific light receiving / receiving process based on the reception of the execution command. At this time, the first control unit 20 functions as a sensitivity setting unit and a light reception control unit.

  The first control unit 20 initializes the area designation number K to “1” and represents the representative scanning line L in each area E (for example, the scanning line located at the center of each area E, the scanning line L3 if the first area E1). A light emitting / receiving operation is executed for (S13). That is, the laser light source 11 is caused to perform a light projecting operation at the currently set light projecting light level, and the light reception signal of only the representative scanning line L3 is read from the two-dimensional CCD 15.

  Next, the first control unit 20 determines whether or not the received light amount (peak value) in the representative scanning line is appropriate based on the read received light signal (S15). Specifically, it is determined whether the amount of received light is within a predetermined reference range (a range lower than the saturation level and higher than the noise). If the amount of received light is appropriate (S15: YES), the process proceeds directly to S19.

  On the other hand, when the received light amount is inappropriate (S15: NO), the light projecting / receiving sensitivity (the received light signal level received by the first control unit 20) is changed so that the received light amount falls within the reference range (S17), and thereafter , Go to S19. In the present embodiment, the first control unit 20 changes the light projecting / receiving sensitivity by changing the duty ratio of the operation signal Sa given to the laser driving circuit 13 and changing the light projection amount of the laser light source 11. Specifically, the amount of emitted light is increased if the amount of received light is lower than the reference range, and the amount of emitted light is decreased if the amount of received light is higher than the reference range. As a method of changing the light projecting / receiving sensitivity, for example, the amplification degree of the received light signal in the CCD drive circuit 17 may be changed.

  When the amount of received light becomes appropriate (S15: YES), the received light position data based on the received light signal is transmitted to the controller 30 in association with each region E (or representative scanning line L). When the unprocessed region remains (S21: NO), the first control unit 20 adds “1” to the region designation number K and returns to S13, and the same processing is performed for the second region and thereafter. repeat.

  If the process has been completed for all areas E (S21: YES), this area-specific light projection / reception process is terminated. Thereby, the displacement sensor 10 can transmit the light receiving position data acquired under appropriate light projecting / receiving sensitivity for each region E to the controller 30. Then, the second control unit 33 of the controller 30 compares the height difference between the regions E with a predetermined threshold based on the received light receiving position data for each region E, thereby covering the main body W1 with the lid portion. It is determined whether or not W2 is properly fitted, and a determination signal corresponding to the determination result is output to a host device (not shown). At this time, the second control unit 33 functions as a light reception control unit. As another detection process, for example, a display lamp (not shown) provided in the displacement sensor 10 may be turned on, or a determination result may be displayed on the display unit 31 of the controller 30. Further, the distance (displacement) between the displacement sensor 10 and each part of the object W may be detected (measured).

(Effect of this embodiment)
According to the displacement sensor system 1 of this embodiment, individual light projecting / receiving sensitivity can be set corresponding to each different area E on the imaging surface 15A, and the light reception signal of the scanning line L in each area E is It can be taken out under the light projecting / receiving sensitivity corresponding to the region E. Therefore, even if the object W has non-uniform reflectance, the lid W2 of the object W is set by setting the light projecting / receiving sensitivity corresponding to the reflectance of the part for each region E on the imaging surface 15A corresponding to each part. It is possible to determine whether the is fitted normally.

  In addition, since the above determination can be made based on the light reception signals of only the representative scanning lines L of each region E, the processing can be performed at a higher speed than the configuration using the light reception signals of all the scanning lines on the imaging surface.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and the drawings, and for example, the following various aspects are also included in the technical scope of the present invention. In particular, among the constituent elements of each embodiment, constituent elements other than the constituent elements of the top-level invention can be omitted as appropriate because they are additional elements.
(1) Although the displacement sensor system including the displacement sensor 10 and the controller 30 has been described in the above embodiment, the present invention is not limited to this. For example, a configuration in which at least one of the display unit 31 and the operation unit 37 is provided on the displacement sensor 10 side, or a configuration in which the second control unit 33 of the controller 30 executes an area designation process may be used.

  (2) In the above-described embodiment, the position of the pixel at which the light reception amount reaches the peak is detected as the light reception position on the scanning line L, but the present invention is not limited to this. For example, a pixel having a light reception level of a predetermined value or more is extracted from the pixels on the scanning line L, and the center position and the gravity center position of the extracted pixel group (the position of each pixel is weighted according to the amount of received light). (Average position) may be the light receiving position.

  (3) In the above embodiment, each scanning line L and the shape based on the light receiving position of each scanning line L are displayed on the display unit 31 (graphic display), but the present invention is not limited to this. For example, the specific information of each scanning line L and the position information of the light receiving position may be numerically displayed with characters, symbols, and the like.

  (4) In addition, after performing the region-specific light projecting / receiving process, the shape based on each scanning line L and the light receiving position of each scanning line L for each region E is displayed on the display unit 31 so that the region designation can be changed. Also good. With such a configuration, the area can be specified more accurately. At this time, for all the regions E, it is preferable to simultaneously display the shapes based on the light receiving positions on the display unit 31.

  (5) In the above embodiment, the height difference of the object W is measured based on the light reception signal of only the representative scanning line L of each region E in the measurement process, but the present invention is not limited to this. For example, the surface shape of the object W may be measured based on the light reception signals of all the scanning lines L in each region E.

  (6) In the above embodiment, the light projecting / receiving sensitivity is adjusted based on the light reception signal for each region E in the measurement process, but the present invention is not limited to this. For example, a predetermined value for each region E may be set as the light projecting / receiving sensitivity. However, with the configuration of the above embodiment, the light projecting / receiving sensitivity can be set to an appropriate value in accordance with changes in the surrounding environment.

DESCRIPTION OF SYMBOLS 1 ... Displacement sensor system 10 ... Displacement sensor 11 ... Laser light source (light projection part)
15. Two-dimensional CCD (two-dimensional image sensor)
15A ... imaging surface 17 ... CCD drive circuit (light receiving processing part)
20 ... 1st control part (light reception control part, sensitivity setting part, area designation part)
21. Data processing unit (output unit)
L ... Scanning line W ... Object

Claims (5)

A light projecting unit that irradiates the object with linear light;
A two-dimensional imaging device having an imaging surface capable of receiving linear reflected light irradiated from the light projecting unit and reflected by the object;
A light reception processing unit that extracts a light reception signal corresponding to the amount of light received by each pixel on the imaging surface for each scanning line intersecting a light reception image of the linear reflected light;
An area designating unit for designating a plurality of areas on the imaging surface in units of scanning lines;
A sensitivity setting unit capable of setting individual light receiving / receiving sensitivity corresponding to each region specified by the region specifying unit;
Under the light projecting / receiving sensitivity corresponding to each area designated by the area designating section, only the light receiving signal of the scanning line in the area is taken out by the light receiving processing section, and detection processing corresponding to the taken out light receiving signal is performed. A displacement sensor system comprising: a light reception control unit to be executed. The displacement sensor system according to claim 1,
A display unit;
A display control unit for displaying information on at least one of a light receiving position and a light receiving amount in each scanning line on the display unit based on a light receiving signal extracted by the light receiving processing unit;
An operation unit,
The said area designation | designated part is a displacement sensor system which is the structure which designates the said area | region based on operation by the user in the said operation part. The displacement sensor system according to claim 2,
The display control unit is a displacement sensor system that simultaneously displays a light receiving position based on a light receiving signal taken out under a light projecting / receiving sensitivity corresponding to each region on the display unit. A light projecting unit that irradiates the object with linear light;
A two-dimensional imaging device having an imaging surface capable of receiving linear reflected light irradiated from the light projecting unit and reflected by the object;
A light reception processing unit that extracts a light reception signal corresponding to the amount of light received by each pixel on the imaging surface for each scanning line intersecting a light reception image of the linear reflected light;
A sensitivity setting unit capable of setting individual light receiving / receiving sensitivity corresponding to different areas on the imaging surface;
A light reception control unit that causes the light reception processing unit to extract only the light reception signal of the scanning line in the region under the light projection / reception sensitivity corresponding to the region, and executes a detection process based on the extracted light reception signal. Displacement sensor. The displacement sensor according to claim 4,
A displacement sensor comprising: an output unit that outputs information on at least one of a light receiving position and a light receiving amount based on a light receiving signal extracted with a light projecting / receiving sensitivity corresponding to each region.

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