JP2006064385A - Apparatus and method for measuring shape - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low-cost shape measuring apparatus having high measurement accuracy even though it is of a noncontact type and capable of simultaneously maintaining a wide measuring range, a characteristic of a noncontact type, and speeding up measurements. <P>SOLUTION: The shape measuring apparatus is provided with a plurality of three-dimensional position sensors and comprises both a converting means for converting three-dimensional position data, surface data from each three-dimensional position sensor, into point data groups and a processing unit for measuring the shape of an object to be measured on the basis of the point data groups from the converting means. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a shape measuring device and a shape measuring method.

  In so-called three-dimensional measurement systems, three-dimensional measurement based on stereo vision using a large-sized and high-resolution image input device, or a measurement needle on the surface plate is brought into contact with the object to be measured directly. In general, a method called a stylus method for measuring distance has been used.

  The former is inevitably an expensive system due to the improvement in resolution and the accompanying increase in processing amount when trying to increase the accuracy, and it is difficult to improve the accuracy in terms of the principle of the system. On the other hand, the latter is relatively easy to obtain high accuracy, but since the overall shape is obtained from the measurement results for each point, not only continuous measurement is possible, but measurement requires a lot of time and labor. It will be. Moreover, since it was a contact type, it had the fault that a soft surface could not be made into a measuring object.

  The present invention provides a low-cost shape measuring device and a shape measuring method that have high measurement accuracy while maintaining a wide measurement area, which is a feature of the non-contact method, and at the same time speed up the measurement. The purpose is to do.

  To achieve the above object, the invention described in claim 1 includes a plurality of three-dimensional position sensors, and conversion means for converting three-dimensional position data, which is surface data from each three-dimensional position sensor, into a point data set. And a processing device for measuring the shape of the object to be measured based on the point data set from the conversion means.

  According to a second aspect of the present invention, in the shape measuring apparatus according to the first aspect, the conversion means is provided in each of a plurality of three-dimensional position sensors.

  According to a third aspect of the present invention, in the shape measuring apparatus according to the first or second aspect, the converting means converts the three-dimensional position data, which is surface data from each three-dimensional position sensor, to x, y, It is characterized in that it is converted into three point data sets consisting of three positional parameters consisting of z.

  According to a fourth aspect of the present invention, in the shape measuring apparatus according to the first or second aspect, the converting means converts the three-dimensional position data, which is surface data from each three-dimensional position sensor, to x, y, It is characterized by being converted into six point data sets consisting of three positional parameters consisting of z and Euler angles φ, θ, ψ.

  According to a fifth aspect of the present invention, in the shape measuring apparatus according to any one of the first to fourth aspects, each conversion means provided in each of a plurality of three-dimensional position sensors is configured to perform the processing. The point data sets from each conversion means are input in parallel to the processing device, and are connected to the processing device in parallel.

  According to a sixth aspect of the present invention, in the shape measuring apparatus according to any one of the first to fourth aspects, the point data from each conversion means provided in each of the plurality of three-dimensional position sensors. The set is characterized by being input to the processing device as a serial signal.

  The invention according to claim 7 is the shape measuring apparatus according to any one of claims 1 to 6, wherein a predetermined target is provided on the object to be measured, and an imaging region of the three-dimensional position sensor for each target. Is set to be larger than the target area.

  The invention according to claim 8 is the shape measuring apparatus according to any one of claims 1 to 6, wherein a predetermined target patterned on the object to be measured is provided, and a three-dimensional position relative to the target is provided. The imaging region of the sensor is set to be smaller than the target area.

  The invention according to claim 9 is the shape measuring apparatus according to claim 8, wherein the patterning of the target is composed of linear patterns in the X direction and the Y direction with respect to the measurement coordinates. It is a feature.

  The invention described in claim 10 is the shape measuring apparatus according to claim 8, wherein the patterning of the target is configured by combining a plurality of linear patterns in the X direction and the Y direction. .

  The eleventh aspect of the present invention is the shape measuring apparatus according to the ninth or tenth aspect, wherein the patterning of the target is a combination of combinations of different linear patterns in the X and Y directions. It is characterized by becoming.

  According to a twelfth aspect of the present invention, in the shape measuring apparatus according to any one of the eighth to eleventh aspects, the target is color-coded with a different spectrum, and the light receiving unit of the three-dimensional position sensor is It is characterized by having a color filter that matches the spectral characteristics of these colors.

  The invention according to claim 13 is the shape measuring apparatus according to any one of claims 8 to 12, wherein the target is provided with a concavo-convex shaped object whose distance in the Z-axis direction is a known amount. It is characterized by being.

  Further, the invention according to claim 14 is the shape measuring apparatus according to claim 13, wherein the target is provided with a plurality of uneven shapes, and each uneven shape has a known amount of distance in the Z-axis direction. It is characterized by taking different values.

  Further, the invention according to claim 15 is the shape measuring device according to claim 13 or claim 14, wherein the plurality of uneven shapes provided on the target are arranged in the X and Y coordinates of the uneven shape on the target. Is known in advance.

  Further, the invention according to claim 16 is the shape measuring apparatus according to claim 13 or claim 14, wherein the concavo-convex shaped object provided on the target has a step shape whose distance in the Z-axis direction is a known amount. It is characterized by being.

  The invention according to claim 17 includes a plurality of three-dimensional position sensors, converts three-dimensional position data, which is surface data from each three-dimensional position sensor, into a point data set, and based on the converted point data set. Measure the shape of the object to be measured.

  According to the invention described in claims 1 to 17, a plurality of three-dimensional position sensors are provided, the three-dimensional position data, which is surface data from each three-dimensional position sensor, is converted into a point data set by the conversion means, and converted. Since the shape of the object to be measured is measured based on the point data set, the problem of the huge amount of 3D data generated in such a system can be solved, data processing can be performed at high speed, high accuracy, and low Cost control can be performed. Specifically, as the processing in the conversion processing means, processing such as obtaining an average value based on the image data from the three-dimensional position sensor, and outputting as 3 to 6 point data, The amount of data can be greatly reduced.

  In particular, in the invention according to claim 3, in the shape measuring apparatus according to claim 1 or 2, the conversion means converts the three-dimensional position data, which is surface data from each three-dimensional position sensor, to x, y, The three-dimensional data set is converted into three point data sets consisting of three position parameters consisting of z, and the three-dimensional image data obtained from the object to be measured is not used as it is, but the measurement area of each three-dimensional position sensor. The representative value is output as three point data sets composed of three positional parameters of x, y, and z. Thereby, compared with the case where 3D image data is handled as it is, the amount of data can be greatly reduced, and the burden on the system, such as subsequent processing and communication volume, can be reduced. In addition, since the 3D position sensor is installed away from these point data, the data of the part that cannot be measured is complemented to obtain the shape of the entire continuous object to be measured. At the same time as measurement is possible, it can be used as a feedback signal for a control system that requires high-speed operation, which is indispensable for monitoring and controlling not only measurement but also actuator movement. As an example of measurement control of a moving object using this, it is possible to perform control such that a free curved surface is obtained by applying the present invention to a planar object to be measured having an actuator. In this case, by using a combination of three-dimensional position sensors having different effective measurement distances, high-precision measurement is possible even if the object to be measured is small to large.

  According to a fourth aspect of the present invention, in the shape measuring apparatus according to the first or second aspect, the conversion means converts the three-dimensional position data, which is surface data from each three-dimensional position sensor, to x, y, Conversion is made to six point data sets consisting of three positional parameters consisting of z and Euler angles φ, θ, ψ. That is, six point data consisting of three position parameters x, y, and z and Euler angles φ, θ, and ψ that are rotation angles of the respective axes are sampled from three-dimensional position data from the measurement object. Output as a set. As a result, as compared with the case where the three-dimensional image data is handled as it is, the amount of data can be greatly reduced as in the third aspect of the invention. Furthermore, in the invention according to claim 4, since the point data is data having a rotation angle as compared with claim 3, the data not measured by the point data is supplemented by later data processing. In this case, it is possible to obtain higher accuracy than in the case of point data of only position.

  Moreover, in invention of Claim 6, in the shape measuring apparatus as described in any one of Claim 1 thru | or 4, it is point data from each conversion means provided in each of several 3D position sensor. The set is input to the processing device as a serial signal, and the point data from each conversion means is sent to the processing device as a serial signal and the shape measurement is performed. As a result, the wiring area is increased as well as restrictions on the degree of freedom of arrangement, and problems such as an increase in size, unstable operation, and an increase in cost can be solved.

  That is, in the invention described in claim 5, when the point data from the conversion means is sent to the processing means, the parallel connection is used. However, in this case, since it is necessary to provide a large number of three-dimensional position sensors in order to accurately measure the shape, the number of connection lines to the processing means becomes enormous and the wiring area is not limited as well as restrictions on the degree of freedom of placement. However, there were problems such as increase in size, unstable operation, and cost increase.

  On the other hand, in the invention of claim 6, since the point data from each conversion means is sent to the processing means as a serial signal, the number of signal lines can be reduced and the degree of freedom in arrangement is limited. Not only can the wiring area be increased, but problems such as increased size, unstable operation, and increased costs can be solved.

  According to a seventh aspect of the present invention, in the shape measuring apparatus according to any one of the first to sixth aspects, a predetermined target is provided on the object to be measured, and the imaging region of the three-dimensional position sensor for each target Is set to be larger than the target area, and the amount of calculation when converting from image data to point data can be reduced by sampling and measuring only the target displacement provided on the surface of the workpiece. Can be provided at a lower cost. Further, by clarifying the contrast between the target and its installation surface (background), the target edge in the image data from the three-dimensional position sensor becomes clear, so that the amount of movement of XY can be detected with high accuracy. As a result, the amount of movement can be measured more accurately by performing continuous temporal shooting.

  In other words, in conventional shape measurement, it is usual to directly measure the shape of the object to be measured. In this case, measurement must be performed based on subtle contrast, and there are problems such as reflection. Yes, the accuracy is not good, and processing takes a lot of time and labor. However, in the invention of claim 7, the object to be measured is provided by an indirect method by providing a predetermined target on the surface of the object to be measured. The above-mentioned problem does not occur because the shape is measured. Also, by setting the measurement area of the three-dimensional position sensor in this case to be larger than the target, compared to the case where the target and the measurement area are the same size, the measured object is subject to a large displacement (movement). The disadvantage that the sensor misses the target can be alleviated.

  According to an eighth aspect of the invention, in the shape measuring apparatus according to any one of the first to sixth aspects, a predetermined target patterned on the object to be measured is provided, and a three-dimensional position relative to the target is provided. The imaging region of the sensor is set to be smaller than the target area. That is, the size of the target provided on the object to be measured is an area larger than the measurement region of the three-dimensional position sensor and artificially patterned. As a result, even when the object to be measured has a large displacement, the target is unlikely to deviate from the measurement region. Further, in the invention of claim 7, in order not to miss the target, the measurement area of the three-dimensional position sensor must be set large, and therefore a large number of pixels are required to improve the resolution (accuracy). However, in the invention of claim 8, the measurement area can be made small, and even with the same number of pixels, the resolution is relatively high with respect to the target. Can be done. Further, since the patterning is performed on the target, the amount of movement can be clarified by detecting the feature of the pattern, and high-precision three-dimensional measurement can be performed.

  According to a ninth aspect of the present invention, in the shape measuring apparatus according to the eighth aspect, the patterning of the target is composed of linear patterns in the X direction and the Y direction with respect to the measurement coordinates. It is a feature. That is, the target is a combination of patterns in which patterning is arranged in the X direction and in the Y direction. In detecting the movement of the object to be measured and the target, the amount of movement of the current XY coordinates is obtained by taking the difference from the image captured immediately before by the three-dimensional position sensor. In this case, a straight line is obtained in the X and Y directions. Because the pattern pattern on the target is clear, the pattern contrast on the image in the target is clear, and the pattern edge of the target image captured by the three-dimensional position sensor is clear. Can be reliably detected.

  The shape measuring apparatus according to claim 10 is characterized in that the patterning of the target is configured by combining a plurality of linear patterns in the X direction and the Y direction. . That is, in the invention described in claim 10, a plurality of linear patterns in the X and Y directions of claim 9 are combined. According to the ninth aspect of the present invention, when the object to be measured moves greatly, measurement must be performed using only one pattern in the X direction or the Y direction. In this case, it is difficult to accurately detect the amount of movement (displacement) in the X direction by measurement using only the linear pattern in the X direction. On the other hand, in the invention of claim 10, since it has a plurality of XY patterns and this problem can be avoided, more accurate measurement is possible.

  A pattern such as a mouth shape or a tabacle can be regarded as an extension of the invention of claim 10.

  Similarly, a pattern having a curve such as a waveform can be regarded as an extension of the invention of claim 10, but this is disadvantageous in the processing amount of the target image captured by the three-dimensional position sensor, Incurs time reduction.

  In the eleventh aspect of the invention, in the shape measuring apparatus according to the ninth or tenth aspect, the patterning of the target is a combination of combinations of different linear pattern intervals in the X and Y directions. It is characterized by becoming. That is, in the invention described in claim 11, the intervals of the linear patterns in the inventions in claims 9 and 10 are appropriately changed. According to the ninth and tenth aspects of the present invention, when the imaging period of the three-dimensional position sensor and the movement amounts of the measurement object and the target coincide with the period of the target pattern, it is difficult to detect or time is spent for calculating the movement amount. There is a problem that takes. On the other hand, in the invention of claim 11, since this defect can be avoided by eliminating the periodicity of the pattern by using, for example, 1 / f fluctuation or random numbers, measurement with higher reliability is possible. Is possible.

  According to a twelfth aspect of the present invention, in the shape measuring apparatus according to any one of the eighth to eleventh aspects, the target is color-coded with a different spectrum, and the light receiving unit of the three-dimensional position sensor is It is characterized by having a color filter that matches the spectral characteristics of these colors. That is, in the invention described in claim 12, the patterns representing the coordinates (positions) within the target are patterns having different spectra (colors), and the light receiving unit of the three-dimensional position sensor distinguishes the spectra of the patterns within the target. The color filter is provided.

  When the target is sufficiently larger than the imaging area, if the target and the object to be measured move out of the imaging area at a higher speed than the imaging period due to, for example, disturbance, the location within the target can be determined only from the image of the 3D position sensor. It becomes impossible to know whether or not the coordinate is measured, and correct coordinate information cannot be obtained. In the invention of the twelfth aspect, as described above, this problem can be avoided by having a rough position in the target as spectrum information, so that measurement with higher reliability is possible.

  In the invention described in claim 13, an uneven shape whose distance in the Z-axis direction is known in advance is provided in the target, and by using this value as a calibration value in the Z-axis direction, high-precision measurement can be performed. .

  In addition, by performing calibration in the Z-axis direction at any time using this, even if there are system instability factors such as temperature changes and changes over time of system components such as three-dimensional input elements and index light sources, the effect of this It is possible to perform stable measurement.

  In addition, by providing protrusions and the like on the object to be measured, this uneven shape does not require an additional target attached to the object to be measured, and a low-cost system can be achieved.

  In the invention of claim 14, in the invention of claim 13, an uneven shape having a different known value in the Z-axis direction is further provided, and an intermediate value can also be used in the calibration in the Z-axis direction. Therefore, the linearity of the Z-axis direction accuracy can be ensured, the calibration in the Z-axis direction becomes more accurate, and high-precision measurement can be performed in the distance measurement in the Z-axis direction.

  Also, in the invention of the fourteenth aspect, as in the invention of the thirteenth aspect, by performing calibration at any time, system instability factors such as temperature change and time-dependent change of system components such as a three-dimensional input element and an index light source are obtained. Even if there is, there is no influence of this, and stable measurement can be performed.

  In the invention described in claim 15, the uneven shape in the invention of claim 13 or claim 14 is arranged on predetermined X and Y coordinates on the target. In the same manner as described above, the rough position in the target is arranged as the uneven shape object.

  Accordingly, as described in the invention of claim 12, “When the target is sufficiently larger than the imaging region, the target and the object to be measured move out of the imaging region at a higher speed than the imaging cycle due to, for example, disturbance, etc. It is not possible to know where the target is being measured from the 3D position sensor image alone, and correct coordinate information cannot be obtained. This enables more reliable measurement. It becomes.

  Further, in the invention according to claim 16, in the shape measuring apparatus according to claim 13 or claim 14, the uneven shape object provided on the target has a step shape whose distance in the Z-axis direction is a known amount. It is characterized by being. That is, in the invention described in claim 16, the target is provided with a concavo-convex shape having a plurality of steps whose distances are known in the Z-axis direction. Thereby, highly accurate three-dimensional measurement can be performed by using the value of this level difference as a calibration value in the Z-axis direction. As a result, the same effect as that of the invention described in claim 14 can be obtained with a single concavo-convex shaped object, so that measurement at a smaller size and lower cost is possible.

Further, by performing calibration at any time, it is possible to perform stable measurement even with respect to temperature and temporal changes of the three-dimensional input element, the index light source, and the like.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  Conventionally, as a small-sized optical device, a photocoupler and a PSD sensor (for example, manufactured by Sharp: model name GP2D12) can be cited.

  These are elements in which a light emitting element and a light receiving element are combined. However, the former simply detects the presence or absence of an object, and the latter detects only a distance and is not intended to measure a three-dimensional object.

  Even if such a small optical device can be used to realize high-precision three-dimensional measurement, in the case of such a device, in principle, the measurement area is limited to an optical element (lens) or device. Only a very small range could be measured, and a large object to be measured could not be measured with high accuracy.

  As a means for realizing a measuring element for a three-dimensional measuring apparatus capable of measuring such a minute region with high accuracy, a prior application (Japanese Patent Application No. 15) filed on February 19, 2003 by the present applicant. -41072).

  In this prior application, a light emitting unit that emits light and a light receiving unit that receives light reflected by an object are integrated, and the position information of the object is obtained based on the light received by the light receiving unit using the principle of triangulation. A plurality of three-dimensional position sensors to be acquired, and the shape of the object is measured based on the position information of the object acquired by the plurality of three-dimensional position sensors.

  According to this prior application, not only a minute area can be measured three-dimensionally with high precision, but also a wide measurement area can be taken and measurement can be performed with high precision. That is, it is possible to realize a three-dimensional measuring apparatus capable of measuring with high accuracy at low cost even if the object to be measured has a small shape to a large shape.

  However, when three-dimensional measurement is performed by combining a plurality of such minute three-dimensional position sensor elements, a large amount of image data or three-dimensional data is generated from each element. Problems arise in capacity and communication bandwidth.

  In other words, the amount of these data is enormous, and when it is attempted to construct a control system by recognizing an entire three-dimensional image, it is difficult to construct a system because high-speed data processing cannot be performed. Had the problem of becoming.

  For example, as an application example of such a three-dimensional measuring apparatus, in a robot having a multi-joint, a super-multi-joint, or a muscular actuator, these movements are measured by a three-dimensional position sensor, and NFB (negative feedback) control is performed. Can be considered. However, in this case, an enormous amount of three-dimensional data is generated, so that high-speed control is difficult in such a conventionally used configuration.

  The present invention further solves the problem of the huge amount of three-dimensional data generated in such a system, and can provide a three-dimensional position measuring device that can perform high-speed data processing, perform high-precision, and low-cost control. Intended to be realized.

  Thus, for example, it is intended to enable a high-speed three-dimensional moving body measurement combining a plurality of three-dimensional position sensors and a control system using the same.

(First form)
A first aspect of the present invention includes a plurality of three-dimensional position sensors, conversion means for converting three-dimensional position data, which is surface data from each three-dimensional position sensor, into a point data set, and point data from the conversion means It has a processing device for measuring the shape of the object to be measured based on the set.

  Here, as each three-dimensional position sensor, for example, a light emitting unit that emits light, a light receiving unit that receives light reflected by the object, and the three-dimensional position information of the object based on the light received by the light receiving unit Can be used which has a processing unit that acquires the data using the principle of triangulation on a single substrate.

  According to the first embodiment, a plurality of three-dimensional position sensors are provided, and the three-dimensional position data, which is the surface data from each three-dimensional position sensor, is converted into a point data set, and based on the converted point data set, Since the shape of the measurement object is measured, it is possible to solve the problem of the huge amount of three-dimensional data generated in such a system, to perform data processing at high speed, and to perform high-accuracy and low-cost control. .

(Second form)
According to a second aspect of the present invention, in the shape measurement apparatus according to the first aspect, the conversion unit is provided in each of a plurality of three-dimensional position sensors.

  In this case, the function as the conversion means can be provided to the processing unit of the three-dimensional position sensor.

(Third form)
According to a third aspect of the present invention, in the shape measuring apparatus according to the first or second aspect, the converting means converts three-dimensional position data, which is surface data from each three-dimensional position sensor, from x, y, z. It is characterized in that it is converted into three point data sets consisting of three positional parameters.

  According to a third aspect, in the shape measuring apparatus according to the first or second aspect, the conversion means converts three-dimensional position data, which is surface data from each three-dimensional position sensor, into three pieces of x, y, and z. Instead of using the three-dimensional image data obtained from the object to be measured as it is as a representative value for the measurement area of each three-dimensional position sensor, x, The data is output as three point data sets composed of three positional parameters y and z. Thereby, compared with the case where 3D image data is handled as it is, the amount of data can be greatly reduced, and the burden on the system, such as subsequent processing and communication volume, can be reduced. In addition, since the 3D position sensor is installed away from these point data, the data of the part that cannot be measured is complemented to obtain the shape of the entire continuous object to be measured. At the same time as measurement is possible, it can be used as a feedback signal for a control system that requires high-speed operation, which is indispensable for monitoring and controlling not only measurement but also actuator movement. As an example of measurement control of a moving object using this, it is possible to perform control such that a free curved surface is obtained by applying the present invention to a planar object to be measured having an actuator. In this case, by using a combination of three-dimensional position sensors having different effective measurement distances, high-precision measurement is possible even if the object to be measured is small to large.

(4th form)
According to a fourth aspect of the present invention, in the shape measuring apparatus according to the first or second aspect, the conversion means converts the three-dimensional position data, which is surface data from each three-dimensional position sensor, from x, y, z. It is characterized in that it is converted into six point data sets consisting of the following three positional parameters and Euler angles φ, θ, ψ.

  That is, six point data consisting of three position parameters x, y, and z and Euler angles φ, θ, and ψ that are rotation angles of the respective axes are sampled from three-dimensional position data from the measurement object. Output as a set. As a result, as compared with the case where the three-dimensional image data is handled as it is, the amount of data can be greatly reduced as in the third aspect of the invention. Furthermore, in the invention according to claim 4, since the point data is data having a rotation angle as compared with claim 3, the data not measured by the point data is supplemented by later data processing. In this case, it is possible to obtain higher accuracy than in the case of point data of only position.

(5th form)
According to a fifth aspect of the present invention, in the shape measurement apparatus according to any one of the first to fourth aspects, each conversion unit provided in each of the plurality of three-dimensional position sensors is connected in parallel to the processing device. The point data set from each conversion means is input to the processing device in parallel.

(Sixth form)
According to a sixth aspect of the present invention, in the shape measuring apparatus according to any one of the first to fourth aspects, the point data set from each conversion unit provided in each of the plurality of three-dimensional position sensors is the above processing. It is characterized by being input as a serial signal to the device.

  That is, in the sixth aspect, in the shape measuring apparatus according to any one of the first to fourth aspects, the point data set from each conversion unit provided in each of the plurality of three-dimensional position sensors is the processing device. As a serial signal, the point data from each conversion means is sent as a serial signal to the processing device for shape measurement.

  In the fifth embodiment described above, parallel connection is used when sending point data from the conversion means to the processing means. However, in this case, since it is necessary to provide a large number of three-dimensional position sensors in order to accurately measure the shape, the number of connection lines to the processing means becomes enormous and the wiring area is not limited as well as restrictions on the degree of freedom of placement. However, there were problems such as increase in size, unstable operation, and cost increase.

  On the other hand, in the sixth embodiment, since the point data from each conversion means is sent to the processing means as a serial signal, the number of signal lines can be reduced, and only the restriction on the degree of freedom of arrangement is possible. In addition, the wiring area increases, and problems such as an increase in size, unstable operation, and cost increase can be solved.

(7th form)
According to a seventh aspect of the present invention, in the shape measurement apparatus according to any one of the first to sixth aspects, a predetermined target is provided on the object to be measured, and the imaging area of the three-dimensional position sensor for each target is larger than the target area. It is characterized by a large setting.

  In the seventh aspect, in the shape measuring apparatus according to any one of the first to sixth aspects, a predetermined target is provided on the object to be measured, and the imaging region of the three-dimensional position sensor for each target is set larger than the target area. By sampling only the target displacement provided on the surface of the object to be measured, the amount of calculation when converting from image data to point data can be reduced, and faster processing is possible. Can be provided at low cost. Further, by clarifying the contrast between the target and its installation surface (background), the target edge in the image data from the three-dimensional position sensor becomes clear, so that the amount of movement of XY can be detected with high accuracy. As a result, the amount of movement can be measured more accurately by performing continuous temporal shooting.

  In other words, in conventional shape measurement, it is usual to directly measure the shape of the object to be measured. In this case, measurement must be performed based on subtle contrast, and there are problems such as reflection. Yes, accuracy is not good, and processing takes a lot of time and labor, but in the seventh embodiment, by providing a predetermined target on the surface of the object to be measured, the shape of the object to be measured can be obtained indirectly. The above-mentioned problem does not occur. Also, by setting the measurement area of the three-dimensional position sensor in this case to be larger than the target, compared to the case where the target and the measurement area are the same size, the measured object is subject to a large displacement (movement). The disadvantage that the sensor misses the target can be alleviated.

(Eighth form)
According to an eighth aspect of the present invention, in the shape measuring apparatus according to any one of the first to sixth aspects, a predetermined target patterned on the object to be measured is provided, and an imaging region of the three-dimensional position sensor with respect to the target is provided. It is characterized by being set smaller than the target area.

  That is, in the eighth embodiment, it is assumed that the size of the target provided on the object to be measured is artificially patterned with an area larger than the measurement region of the three-dimensional position sensor. As a result, even when the object to be measured has a large displacement, the target is unlikely to deviate from the measurement region. In the seventh embodiment, in order not to miss the target, the measurement area of the three-dimensional position sensor must be set large, and thus a large number of pixels is required to improve the resolution (accuracy). However, in the eighth embodiment, the measurement area can be reduced, and even with the same number of pixels, it has a relatively high resolution with respect to the target, so that high-precision measurement can be performed. . Further, since the patterning is performed on the target, the amount of movement can be clarified by detecting the feature of the pattern, and high-precision three-dimensional measurement can be performed.

(9th form)
According to a ninth aspect of the present invention, in the shape measuring apparatus according to the eighth aspect, the patterning of the target is configured by linear patterns in the X direction and the Y direction with respect to the measurement coordinates. It is said.

  That is, in the ninth embodiment, the target is a combination of patterns in which patterning is arranged in the X direction and in the Y direction. In detecting the movement of the object to be measured and the target, the amount of movement of the current XY coordinates is obtained by taking the difference from the image captured immediately before by the three-dimensional position sensor. In this case, a straight line is obtained in the X and Y directions. Because the pattern pattern on the target is clear, the pattern contrast on the image in the target is clear, and the pattern edge of the target image captured by the three-dimensional position sensor is clear. Can be reliably detected.

(10th form)
According to a tenth aspect of the present invention, in the shape measuring apparatus according to the eighth aspect, the patterning of the target is configured by combining a plurality of linear patterns in the X direction and the Y direction.

  That is, in the tenth embodiment, a plurality of linear patterns in the X and Y directions of the ninth embodiment are combined. In the ninth embodiment, when the object to be measured moves greatly, measurement must be performed using only one pattern in the X direction or the Y direction. In this case, it is difficult to accurately detect the amount of movement (displacement) in the X direction by measurement using only the linear pattern in the X direction. On the other hand, the tenth embodiment has a plurality of XY patterns, and this problem can be avoided, so that measurement with higher accuracy is possible.

  A pattern such as a mouth shape or a tabacle can be regarded as an extension of the tenth embodiment.

  Similarly, a pattern having a curve such as a waveform can be regarded as an extension of the tenth embodiment, but this is disadvantageous in the processing amount of the target image captured by the three-dimensional position sensor, and the processing time Cause a decline.

(Eleventh form)
According to an eleventh aspect of the present invention, in the shape measuring apparatus according to the ninth or tenth aspect, the patterning of the target is a combination of different linear pattern intervals in the X and Y directions. It is characterized by being.

  That is, in the eleventh embodiment, the linear pattern interval in the ninth and tenth embodiments is appropriately changed. In the ninth and tenth embodiments, when the imaging period of the three-dimensional position sensor and the movement amount of the measurement object and the target coincide with the period of the target pattern, it is difficult to detect or it takes time to calculate the movement amount. There is a bug. On the other hand, in the eleventh embodiment, this problem can be avoided by eliminating the periodicity of the pattern using, for example, 1 / f fluctuation or random numbers, so that more reliable measurement can be performed. It becomes possible.

(Twelfth embodiment)
According to a twelfth aspect of the present invention, in the shape measurement apparatus according to any one of the eighth to eleventh aspects, the target is color-coded with a different spectrum, and the light receiving unit of the three-dimensional position sensor It is characterized by having a color filter that matches the spectral characteristics.

  That is, in the twelfth embodiment, patterns representing coordinates (positions) in the target are patterns having different spectra (colors), and the light receiving unit of the three-dimensional position sensor has colors for distinguishing the spectra of the patterns in the target. A filter is provided.

  When the target is sufficiently larger than the imaging area, if the target and the object to be measured move out of the imaging area at a higher speed than the imaging period due to, for example, disturbance, the location within the target can be determined only from the image of the 3D position sensor. It becomes impossible to know whether or not the coordinate is measured, and correct coordinate information cannot be obtained. In the twelfth embodiment, as described above, by having a rough position in the target as spectrum information, this problem can be avoided, so that measurement with higher reliability is possible.

(13th form)
According to a thirteenth aspect of the present invention, in the shape measuring apparatus according to any one of the eighth to twelfth aspects, the target is provided with an uneven shape object having a known distance in the Z-axis direction. It is a feature.

  In the thirteenth embodiment, an uneven shape whose distance in the Z-axis direction is known in advance is provided in the target, and by using this value as a calibration value in the Z-axis direction, highly accurate measurement can be performed.

  In addition, by performing calibration in the Z-axis direction at any time using this, even if there are system instability factors such as temperature changes and changes over time of system components such as three-dimensional input elements and index light sources, the effect of this It is possible to perform stable measurement.

  In addition, by providing protrusions and the like on the object to be measured, this uneven shape does not require an additional target attached to the object to be measured, and a low-cost system can be achieved.

(14th form)
According to a fourteenth aspect of the present invention, in the shape measuring apparatus according to the thirteenth aspect, the target is provided with a plurality of uneven shapes, and each uneven shape has a known amount of distance in the Z-axis direction. It is characterized by taking values.

  In the fourteenth embodiment, an uneven shape having a different known value in the Z-axis direction is further provided in the thirteenth embodiment, and an intermediate value can also be used in the calibration in the Z-axis direction. The linearity of the direction accuracy can be ensured, the calibration in the Z-axis direction becomes more accurate, and high-precision measurement can be performed in the distance measurement in the Z-axis direction.

  In addition, by performing calibration as needed in the same manner as in the thirteenth embodiment, even if there is a system instability factor such as a temperature change or a change over time of system components such as a three-dimensional input element and an index light source, the influence of this is affected. Escape and stable measurement can be performed.

(15th form)
According to a fifteenth aspect of the present invention, in the shape measuring apparatus according to the thirteenth or fourteenth aspect, the plurality of uneven shapes provided on the target are arranged so that the X and Y coordinates of the uneven shapes on the target are in advance. It is characterized by being known.

  That is, in the fifteenth embodiment, the concavo-convex shaped object in the thirteenth or fourteenth embodiment is arranged on the predetermined X and Y coordinates on the target, and this combination shows the twelfth embodiment. Similarly, it has the rough position in the target as the arrangement of the concavo-convex shape object.

  Accordingly, as described in the twelfth embodiment, “if the target is sufficiently larger than the imaging region, the target and the object to be measured move out of the imaging region at a higher speed than the imaging period due to, for example, disturbance, etc. It is not possible to know where the target is being measured from the original position sensor image alone, and correct coordinate information cannot be obtained.This enables measurement with higher reliability. Become.

(16th form)
According to a sixteenth aspect of the present invention, in the shape measuring apparatus according to the thirteenth or fourteenth aspect, the uneven shape object provided on the target has a step shape whose distance in the Z-axis direction is a known amount. It is characterized by.

  That is, in the sixteenth embodiment, the target is provided with a concavo-convex shape having a plurality of steps whose distances are known in the Z-axis direction. Thereby, highly accurate three-dimensional measurement can be performed by using the value of this level difference as a calibration value in the Z-axis direction. As a result, the same effect as described in the fourteenth embodiment can be obtained with a single concavo-convex shaped object, so that measurement with a smaller size and lower cost is possible.

  Further, by performing calibration at any time, it is possible to perform stable measurement even with respect to temperature and temporal changes of the three-dimensional input element, the index light source, and the like.

  Conventional three-dimensional input systems using images have been treated as natural images as they are measured. In the present invention, although a three-dimensional input method using an image is employed, the image (x), x, y, and z coordinates based on an image obtained by measuring a part of the object to be measured is not used as data. The amount of data is remarkably reduced by converting these parameters into six parameters obtained by adding the three parameters, φ, θ, and ψ, which are the rotation angles of the x, y, and z axes. As a result, the communication amount of the system and the processing amount of the subsequent stage can be reduced, so that the measurement can be speeded up, downsized, and the cost can be reduced. Further, the entire image of the object to be measured can be returned to the image data again from the discretized data of x, y, z, φ, θ, and ψ, and measurement using this can be performed.

  In addition, since the object to be measured is mainly intended for machine control and is used in an artificial environment, the object to be measured is not treated as a natural image as a target of an image input device, but a part of the system. As described above, an artificially designed target is provided on the object to be measured, and this target is measured using an image input device, thereby enabling stable and highly accurate measurement.

  In the above-described example, the function as the conversion unit is provided to the processing unit of the three-dimensional position sensor. However, the function of the conversion unit may be provided separately from the processing unit. However, it is preferable for downsizing or the like that the function of the conversion means is provided in the processing unit.

  In the above-described example, as each three-dimensional position sensor, a light emitting unit that emits light, a light receiving unit that receives light reflected by the object, and a three-dimensional position of the object based on the light received by the light receiving unit. Although a configuration in which a processing unit that acquires information using the principle of triangulation method is provided on a single substrate can be used, a configuration having other configurations can also be used. For example, the processing unit may be configured on a different substrate from the light emitting unit and the light receiving unit, and the present invention can be similarly applied even if each three-dimensional position sensor has an arbitrary configuration.

  Hereinafter, a basic configuration example of the present invention will be described.

  First, as shown in FIG. 1, the basic configuration example of the present invention assumes a three-dimensional position detection apparatus provided with a three-dimensional position sensor for a measurement object that is also considered to be a moving object.

  FIG. 2 shows a basic configuration example of the three-dimensional position sensor. Referring to FIG. 2, the three-dimensional position sensor irradiates the object to be measured with a density pattern having a density gradient from the light source (light emitting unit) to the object to be measured, and receives reflected light from the image input device (light receiving unit). And using the output from the image input device (light receiving unit), the image data is input by performing processing with a position data calculator (XY direction computing unit, Z direction computing unit in the processing unit) as shown in FIG. The distance (Z) between the device (light receiving unit) and the object to be measured can be measured. This is widely known as the intensity ratio method. In the intensity ratio method, a two-dimensional image having a density distribution is projected onto a target space including an object to be measured, and a space irradiated with the pattern is photographed using an image input device (light receiving unit). This is a method for obtaining three-dimensional information. The intensity ratio method is a well-known method and will not be described further. Of course, this method is an example of the present invention, and the use of other distance measuring methods does not impair the basic effect of the present invention.

  The present invention will be described more specifically.

  As the three-dimensional position sensor in the present invention, the same one as in the above-mentioned prior application can be used.

  Moreover, in this invention, as shown in FIG. 1, the case where a to-be-measured object is a moving body is assumed.

  When trying to control the surface of the object to be measured in a free shape, or in a multi-joint, super-multi-joint, or muscle-type robot, grasp these shapes with a three-dimensional position sensor, and this three-dimensional data Based on the above, when trying to perform NFB (negative feedback) control of these measured objects, the conventional sensor has problems such as taking too much time for processing or being too large to fit in the limb, I can't find a suitable solution.

  For example, the contact type has a problem in reliability because it is large and requires a very large number of elements and is a mechanical device. In addition, when trying to use the capacitance type, there are many problems such as a slow measurement speed and a weak noise environment.

  Here, using the three-dimensional position sensor as in the previous application and performing NFB control based on the three-dimensional data based on the measurement data from now on, not only can the above problems be solved, but also integration is possible, so an intelligent actuator can be used. I can make it.

  However, in such a system, if the surface of the object to be measured is controlled to a free shape or if 3D data is used to control a moving object, the data volume of the conventional 3D measurement method Has become enormous, data processing is difficult, and 3D images cannot be recognized at high speed.

  FIG. 4 shows a first specific example of the present invention. This first specific example corresponds to the first, second, third, fourth and fifth embodiments.

  In the first specific example of the present invention, as shown in FIG. 4, in the system for measuring the three-dimensional shape of the object to be measured, the three-dimensional position data that is the surface data from each three-dimensional position sensor is, for example, 3 By converting into one position parameter x, y, z, it is possible to reduce the burden on the system that has been required to directly handle a large amount of image data and surface data. Examples of conversion from surface data to three position parameters (point data) include using the average value of surface data, using the maximum value of surface data, or using only the image center of surface data. Alternatively, it is possible to use an average value obtained by blocking and weighting the surface data.

  In the first specific example of the present invention, the point data from each three-dimensional position sensor is input to the processing device as a parallel signal, the synthesis processing is performed in the processing device, and the three-dimensional whole image is output as data that can be recognized. It is supposed to let you.

In the example of FIG. 4, the case where each three-dimensional position sensor measures a measured object by itself is shown. However, as described in the prior application, the sensors are not adjacent to the sensor but are adjacent or close to each other. You may make it measure in combination with a three-dimensional position sensor (For example, combination of sensor _AT , _BR, etc. in FIG. 4).

  In the above example, the three-dimensional position data, which is the surface data from each three-dimensional position sensor, is converted into, for example, three position parameters x, y, z. A certain three-dimensional position data is converted into six point data (6 DOF data) of Euler angle data φ, θ, ψ indicating three position parameters x, y, z and their inclinations (rotation angles), and outputted. Anyway.

  In this case, since these data are also data having a rotation angle, the position of the blank portion data not measured (sampled) by the three-dimensional position sensor is estimated and interpolated by later data processing. Compared with the case of using only the data (three position parameters), it can be performed with higher accuracy.

  FIG. 5 shows a second specific example of the present invention. This second specific example corresponds to the first, second, third, fourth and sixth embodiments.

  The example of FIG. 5 is different from FIG. 4 in that the input from each three-dimensional position sensor is input to the processing device as a serial signal instead of in parallel.

  6 and 7 show a third specific example of the present invention. Here, FIG. 7 is a diagram showing the relationship between the target and the measurement region in FIG. Note that this third specific example corresponds to the seventh embodiment.

  In the third specific example of the present invention, as shown in FIG. 6, a plurality of targets are provided on the object to be measured, and the light emitting section (index) of the three-dimensional position sensor shown in FIGS. The light from the light source is irradiated, only the target portion is measured, and the target shift is output as the point data described above. The measurement area in this case is set to perform measurement in a wider range than the target.

  In addition, in the example of FIG. 7, although the shape of a target is a rectangle, other shapes, such as circular shape, can also be used as a target shape.

  Further, the target may be displayed by means such as directly painting the object to be measured.

  FIG. 8 shows a fourth specific example of the present invention. This fourth specific example corresponds to the eighth embodiment.

  In the fourth specific example, as shown in FIG. 8, contrary to the third specific example, the measurement region of the three-dimensional position sensor has an area sufficiently smaller than the area of the target. In this case, the target provided on the object to be measured is an artificially patterned target.

  During measurement, these target patterns are measured to measure the movement of the relative positional relationship between the three-dimensional position sensor and the target, and to obtain the difference between the initial positional relationship between the target and the object to be measured. Thus, the movement of the object to be measured can be known.

  FIG. 9 shows a fifth example of the present invention. This fifth specific example corresponds to the ninth embodiment.

  In the fifth specific example, as shown in FIG. 9, the patterning of the target in the fourth specific example is performed by arranging linear patterns in the X direction and the Y direction with respect to the position coordinates of the measurement object. Yes.

  It is desirable that this pattern has a strong contrast and the edges can be detected clearly. In addition, when using the intensity ratio method, in order to reduce the influence on the Z-axis measurement, it is necessary to consider such as making the pattern density sparse.

  FIG. 10 shows a sixth specific example of the present invention. The sixth specific example corresponds to the tenth embodiment.

  In the sixth specific example, as shown in FIG. 10, a plurality of combinations of linear patterns in the X and Y directions in the fifth specific example are provided.

  11 to 14 show a seventh example of the present invention. The seventh specific example corresponds to the eleventh embodiment.

  In the seventh specific example, as shown in FIG. 11, in the linear pattern in the fifth or sixth specific example, for example, by using 1 / f fluctuation or random number, the interval between the lines is different. As a matter of fact, the periodicity of the pattern is lost. As an example of these linear patterns, as shown in FIG. 12 to FIG. 14, a linear pattern having a different interval between lines and having no periodicity is combined.

  FIG. 15 shows an eighth example of the present invention. This eighth example corresponds to the twelfth embodiment.

  In the eighth specific example, as shown in FIG. 15, patterns representing coordinates (positions) in the target are patterns having different spectra (colors), and these spectra are transmitted to the light receiving unit of the three-dimensional position sensor as electric signals. A color filter is provided for distinguishing as follows.

  Each set of target and color filter may be set to have a large number of different spectra for giving position information. However, it is not realistic in terms of processing time and cost, and generally used RGB (red, It is appropriate to use green, blue).

  Further, the position information may be given by a combination of adjacent colors on the target, for example.

  FIG. 16 shows a ninth example of the present invention. This ninth example corresponds to the thirteenth embodiment.

  In the ninth embodiment, as shown in FIG. 16, a configuration having an uneven shape whose distance in the Z-axis direction is known in advance is arranged on the target. At the time of measurement, these concavo-convex shaped objects are used for calibration in the Z-axis direction. In the example of FIG. 16, the concavo-convex shape is represented by a cylindrical shape, but these may be any shape as long as they are prismatic shapes or other concavo-convex shapes with which the distance in the Z-axis direction can be known. Also good. Moreover, you may process so that to-be-measured object itself may have uneven | corrugated shape.

  FIG. 17 shows a tenth example of the present invention. Note that the tenth example corresponds to the fourteenth embodiment.

  In the tenth specific example, as shown in FIG. 17, a plurality of concavo-convex shaped objects having different distances in the Z-axis direction are provided on the target. At the time of measurement, the Z-axis direction distances of the plurality of uneven shapes are used as calibration values in the Z-axis direction.

  As described above, in the tenth specific example, since the concave and convex objects having different distances in the Z-axis direction are provided, the intermediate value in the Z-axis direction can be calibrated.

  FIG. 18 shows an eleventh example of the present invention. This eleventh example corresponds to the fifteenth embodiment.

  In the eleventh specific example, as shown in FIG. 18, the concave-convex shaped object described in the ninth or tenth specific example is arranged at predetermined XY coordinates on the patterned target.

  FIG. 19 shows a twelfth example of the present invention. This twelfth example corresponds to the sixteenth embodiment.

  In the twelfth specific example, as shown in FIG. 19, a step having a known distance in the Z-axis direction is provided as an uneven shape on the target.

  In such a configuration, the calibration value in the Z-axis direction can be read from the plurality of steps and the calibration can be performed. As a result, the same effect as described in the tenth specific example can be obtained with one uneven shape.

  In addition, such a level | step difference may be comprised by the curved-surface thing of shape which understood smoothly in the Z-axis direction.

The present invention is an application that needs to simultaneously measure the movement amount of XYZ in three axes, specifically, three-dimensional position measurement such as a three-dimensional vibration sensor, a three-dimensional accelerometer, an artificial muscle control, a surface measurement device, It can be used for 3D surface measurement, 3D motion measurement, etc.

It is a figure which shows the three-dimensional position detection apparatus which provided the three-dimensional position sensor with respect to the to-be-measured object also considering that it is a moving body. It is a figure which shows the basic structural example of a three-dimensional position sensor. It is a figure which shows the structural example of a position data calculator. It is a figure which shows the 1st example of this invention. It is a figure which shows the 2nd example of this invention. It is a figure which shows the 3rd example of this invention. It is a figure which shows the 3rd example of this invention. It is a figure which shows the 4th example of this invention. It is a figure which shows the 5th example of this invention. It is a figure which shows the 6th example of this invention. It is a figure which shows the 7th example of this invention. It is a figure which shows the 7th example of this invention. It is a figure which shows the 7th example of this invention. It is a figure which shows the 7th example of this invention. It is a figure which shows the 8th example of this invention. It is a figure which shows the 9th example of this invention. It is a figure which shows the 10th example of this invention. It is a figure which shows the 11th example of this invention. It is a figure which shows the 12th example of this invention.

Claims (17)

A plurality of three-dimensional position sensors, a conversion means for converting the three-dimensional position data, which is surface data from each three-dimensional position sensor, into a point data set, and the shape of the measurement object based on the point data set from the conversion means A shape measuring apparatus comprising: a processing apparatus for measuring The shape measuring apparatus according to claim 1, wherein the conversion unit is provided in each of a plurality of three-dimensional position sensors. 3. The shape measuring apparatus according to claim 1 or 2, wherein the converting means converts three-dimensional position data, which is surface data from each three-dimensional position sensor, into three positional parameters including x, y, and z. A shape measuring device, which is converted into a point data set. 3. The shape measuring apparatus according to claim 1, wherein the converting means converts three-dimensional position data, which is surface data from each three-dimensional position sensor, into three position parameters consisting of x, y, and z and Euler angles. A shape measuring device that converts six point data sets consisting of φ, θ, and ψ. 5. The shape measuring apparatus according to claim 1, wherein each conversion unit provided in each of the plurality of three-dimensional position sensors is connected in parallel to the processing apparatus, and each conversion unit is provided. The shape measuring device is characterized in that the point data set from the means is input to the processing device in parallel. 5. The shape measuring device according to claim 1, wherein a point data set from each conversion unit provided in each of a plurality of three-dimensional position sensors is transmitted as a serial signal to the processing device. A shape measuring device characterized by being input. The shape measuring apparatus according to any one of claims 1 to 6, wherein a predetermined target is provided on the object to be measured, and an imaging region of the three-dimensional position sensor for each target is set larger than the target area. A shape measuring apparatus characterized by that. The shape measuring apparatus according to claim 1, wherein a predetermined target patterned is provided on the object to be measured, and an imaging region of the three-dimensional position sensor for the target is smaller than the target area. A shape measuring device characterized by being set. 9. The shape measuring apparatus according to claim 8, wherein the patterning of the target is configured by a linear pattern in the X direction and the Y direction with respect to the measurement coordinates. 9. The shape measuring apparatus according to claim 8, wherein the patterning of the target is configured by combining a plurality of linear patterns in the X direction and the Y direction. 11. The shape measurement apparatus according to claim 9, wherein the patterning of the target has a configuration in which linear patterns having different intervals in the X direction and the Y direction are combined. apparatus. 12. The shape measuring apparatus according to claim 8, wherein the target is color-coded with a different spectrum, and the light receiving unit of the three-dimensional position sensor matches the spectrum characteristics of these colors. A shape measuring device having a color filter. The shape measurement apparatus according to claim 8, wherein the target is provided with an uneven shape object having a known distance in the Z-axis direction. apparatus. 14. The shape measuring apparatus according to claim 13, wherein the target is provided with a plurality of uneven shapes, and each uneven shape has a known amount of distance in the Z-axis direction different from each other. Measuring device. The shape measuring apparatus according to claim 13 or 14, wherein the plurality of concave and convex shapes provided on the target have an X and Y coordinates of the concave and convex shapes on the target known in advance. A shape measuring device. 15. The shape measuring apparatus according to claim 13, wherein the uneven shape provided on the target has a step shape whose distance in the Z-axis direction is a known amount. Provide multiple 3D position sensors, convert 3D position data, which is surface data from each 3D position sensor, into point data sets, and measure the shape of the measurement object based on the converted point data sets A shape measuring method characterized by

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