JP2011110675A - Shape measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shape measuring device constituted so as to assist rotational operation of a joint part in response to operation of a measurer. <P>SOLUTION: This shape measuring device 100 includes a probe 12 for outputting shape measuring information on a measuring object 51 by scanning the measuring object 51 in a noncontact state by an optical sensor 40, a moving mechanism part 11 having an arm part 11a and two or more of joint parts 11b and movably supporting the probe 12 in a predetermined space, an encoder 21 arranged in the respective joint parts 11b and detecting angle information between the arm parts 11a connected by the joint parts 11b or between the arm part 11a and the probe 12, a driving part 15 arranged in the joint parts 11b and rotatingly driving one arm part 11a or the probe 12 connected by the joint parts 11b to the other arm part 11a, and a control part 20 for operating the driving part 15 by detecting the movement of the probe 12 from the angle information. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a shape measuring apparatus.

  A shape measuring device in which a probe having a non-contact sensor is attached to the tip of an articulated arm, and a device configured to measure the shape of an object to be inspected by manual operation by a measurer (hereinafter, “ (Referred to as Patent Document 1). In such a manual measuring machine, an encoder is attached to the joint, and the moving speed and spatial coordinates of the tip of the moving mechanism (the tip of the most distal arm) can be detected. . When measuring an object to be measured having a complicated shape, manual measurement is performed because it takes time to program driving the apparatus.

JP 2009-192401 A

  When measuring the shape of an object to be inspected with such a manual measuring machine, the moving mechanism including the arm is manually moved. There is a problem that the operation time cannot be endured, and since the operation is performed manually, the movement time of the apparatus is uneven, and the measurement data may not be stable. In addition, the non-contact sensor generally has directivity, but according to manual operation, it is difficult to perform operation in accordance with directivity.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a shape measuring apparatus configured to assist the rotation of the joint in accordance with the operation of the measurer.

  In order to solve the above problems, a shape measuring apparatus according to the present invention includes a probe that scans a measurement object in a non-contact manner by an optical sensor and outputs measurement information of the shape of the measurement object, an arm unit, Each of the connecting portions has a moving mechanism portion that has two or more connecting portions that rotatably connect between the arm portions or between the arm portion and the probe, and that supports the probe so as to move within a predetermined space. One arm part or probe provided in the connecting part and connected between the arm parts connected by the connecting part or between the arm parts and the angle information detecting part for detecting angle information between the arm part and the probe. And a control unit that detects the movement of the probe from the angle information and activates the driving unit in accordance with the movement.

  Such a shape measuring device is provided in each of the connection parts, and has a torque detection part that detects the magnitude and direction of the torque applied to the connection part, and the control part is connected to the connection part in each of the connection parts. It is preferable to operate the drive part provided in the connection part so as to rotate the arm part or the probe in the same direction as the direction of the torque detected by the torque detection part provided in the connection part.

  Moreover, in such a shape measuring apparatus, it is preferable that a control part operates a drive part so that the moving speed of a probe may become in a predetermined range.

  In such a shape measuring apparatus, it is preferable that the moving mechanism unit has three or more connecting units, and the control unit operates the driving unit so that the moving direction of the probe is a predetermined direction.

  In such a shape measuring apparatus, the optical sensor provided in the probe includes a light source, a line light forming optical system that irradiates the object to be measured as light from the light source, and reflected light of the line light. An imaging optical system that forms an image, an imaging device that detects an image of reflected light, and an image detected by the imaging device are configured to measure the shape of the object to be measured. It is preferable to operate the drive unit so that the probe moves in a direction corresponding to the directivity of the optical sensor.

  At this time, the control unit preferably operates the drive unit so that the probe moves in a direction orthogonal to the direction in which the line light extends along the surface of the object to be measured.

  Moreover, it is preferable that a control part operates a drive part so that the image of line light may be located in the approximate center part of an image pick-up element.

  When the shape measuring apparatus according to the present invention is configured as described above, it is possible to assist the rotation of the joint in accordance with the operation of the measurer.

It is explanatory drawing which shows the structure of a shape measuring apparatus. It is a block diagram which shows the basic composition of the control part of a shape measuring apparatus. It is explanatory drawing which shows the structure of the optical sensor provided in the probe. It is a flowchart which shows the shape measurement process by a shape measuring apparatus. It is a flowchart for controlling the action | operation of a drive part.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. First, the configuration of the shape measuring apparatus according to the present embodiment will be described with reference to FIGS. The shape measuring apparatus 100 includes, for example, a shape measuring unit 10 that measures the shape of the object to be measured 51 placed on the stage 50, and the angle information and measurement information output from the shape measuring unit 10. The control unit 20 calculates shape information related to the measurement object 51, and a display unit 30 that outputs the calculated shape information as a three-dimensional image, for example. The object to be measured 51 can be measured even if it is not placed on the stage 50. The shape measuring apparatus 100 is a manual measuring machine configured such that the measurer operates the shape measuring unit 10 to acquire the shape information of the measured object 51.

  The shape measuring unit 10 includes a multi-joint structure moving mechanism 11 in which a plurality of arm portions 11a are connected by a plurality of joint portions (connecting portions) 11b, and a distal end portion (an arm located at the most distal end side) of the moving mechanism portion 11. The probe 12 is configured to be detachable with respect to the distal end portion of the portion 11a via the attachment portion 14, and the proximal end portion of the moving mechanism portion 11 (the proximal end portion of the arm portion 11a located on the most proximal side). And an attached base 13. The joint portion 11b connects the arm portions 11a to each other and rotates (swings) the other arm portion 11a with respect to one arm portion 11a, or an arm portion on the proximal end side with respect to the base 13. There is one that rotates 11a around an axis perpendicular to the ground surface, or one that swings or rotates the probe 12 attached to the attachment portion 14 with respect to the arm portion 11a on the distal end side. .

  Each of the rotation shafts of the joint portion 11b has an angle formed by the arm portion 11a or the probe 12 located on the distal end side connected to the joint portion 11b with respect to the base 13 or the arm portion 11a located on the proximal end side. In order to detect this, an encoder (angle information detection unit) 21 that measures the amount of rotation of the rotating shaft is attached, and the measured values (hereinafter referred to as “angle information”) by these encoders 21 are shown in FIG. As shown, it is output to the control unit 20. The joint 11b includes a torque sensor 27 that is a torque detector that detects torque applied to the joint 11b between the arms 11a to which the joints 11b are connected or between the arm 11a and the probe 12. Is provided. Further, the joint portion 11b rotates (swings) the distal end side arm portion 11a or the probe 12 around the rotation axis with respect to the proximal end side arm portion 11a connected via the joint portion 11b. A drive unit (for example, a motor) 15 is connected. The detection value of the torque sensor 27 (hereinafter referred to as “torque information”) is output to the control unit 20, and the operation of the drive unit 15 is controlled by the control unit 20.

  On the other hand, as shown in FIG. 3, the probe 12 has a light source 41 such as a laser diode and the object to be measured on the stage 50 as a line light by using a toric lens optical system such as a cylindrical lens. 51, a line light forming optical system 42 for irradiating 51, an imaging optical system 43 for forming an image of line light projected on the object 51 to be measured (hereinafter referred to as “line image”), and detecting this line image. An image sensor 44 and an optical sensor 40 are provided. As shown in FIG. 1, the probe 12 is provided with an operation switch 25 for the measurer to instruct the control unit 20 to start and stop the shape measurement of the object 51 to be measured. In addition, in order to convert the light radiated | emitted from the light source 41 into line light, the structure irradiated with a galvano scanner etc. as line light is also realizable.

  Further, as shown in FIG. 2, the control unit 20 uses angle information output from each of the processing unit 22 that controls the shape measurement process of the object 51 to be measured by the shape measuring apparatus 100 and the encoder 21. A position calculation unit 23 for calculating the spatial coordinates and orientation of the probe 12 (coordinates and orientation with a predetermined point in the measurement space as the origin, hereinafter referred to as “position information”), and an image sensor 44 The shape calculation unit 24 that calculates the shape information of the measured object 51 using the line image (hereinafter referred to as “measurement information”) output from the position calculation unit 23 and the position information output from the position calculation unit 23, and the torque sensor 27. Torque information output from the torque sensor 27 that calculates torque (amount and direction) applied to each joint 11b, torque information output from the torque sensor 27, and encoder 21. A driving force assisting part 29 for computing the rotation direction and torque of the driving part 15 for assisting the rotational operation of the joint part 11b using the angle information (or the position information output from the position computing part 23). It is comprised. Note that an output (operation signal) from the operation switch 25 is input to the processing unit 22, and the lighting / extinguishing operation of the light source 41 is controlled by the processing unit 22. Further, the shape information output from the shape calculation unit 24 is stored in, for example, a storage unit 26 provided in the control unit 20, and the shape information is processed by the processing unit 22 and is displayed on the display unit 30. Is output as Here, the measurement space refers to a range (space) in which the shape measuring device 100 can move the probe 12 and acquire the spatial coordinates of the measured object 51. The control unit 20 is realized by a computer, for example, and the processing unit 22, the position calculation unit 23, the shape calculation unit 24, the torque calculation unit 28, and the driving force assisting unit 29 are implemented as programs executed by this computer. .

  Here, since information such as the length of the arm portion 11a is known, the position calculation unit 23 of the control unit 20 is positioned on the base 13 or the base end side based on the angle information output from the encoder 21. By calculating the angle of the arm part 11a or the probe 12 connected to the distal end side with respect to the arm part 11a, three-dimensional coordinates (spatial coordinates) in the space of the probe 12 can be obtained. Similarly, since the positions (coordinates) of the light source 41, the line light forming optical system 42, the imaging optical system 43, and the imaging element 44 in the probe 12 are also known, the shape calculation unit 24 performs imaging based on the principle of triangulation. By processing the measurement information (line image) acquired by the element 44, the shape of the measured object 51 within the range that can be imaged by the imaging element 44 (the shape of the measured object 51 on which the line light is projected (for example, And expressed as a group of coordinates in the measurement space discretely represented in this range))).

  Note that the method for acquiring the shape information of the object 51 to be measured by the probe 12 is not limited to the above-described method by triangulation by light cutting, but also a method of acquiring a bright field image and measuring the shape by computer analysis, or a stereo image. The triangulation method used can be used as appropriate.

  Next, a method for measuring the shape of the measured object 51 using the shape measuring apparatus 100 will be described with reference to FIG. In FIG. 3 described above, the direction in which the measured object 51 is scanned with line light is the x axis, the longitudinal direction of the line light is the y axis, and the direction orthogonal to the x axis and the y axis is the z axis. The operator operates the probe 12 of the shape measuring apparatus 100 and moves the probe 12 to the measurement start position of the measured object 51. Then, the measurer places the probe 12 at a predetermined distance and angle with respect to the object to be measured 51 and turns on the operation switch 25. When detecting that the operation switch 25 is turned on (step S100), the processing unit 22 turns on the light source 41 and irradiates the object to be measured 50 with line light (step S110). In this state, the measurer moves along the measurement target surface of the object to be measured 51 (the x-axis direction in FIG. 3 (the x ′ axis corresponding to the x axis and the x axis along the measurement target surface, hereinafter the x axis and the x axis). Distance of a predetermined height (z-axis direction (z-axis direction or distance between object plane and cutting line, hereinafter collectively referred to as z-axis direction)) ), The surface of the measured object 51 is scanned by moving the probe 12. When the operation switch 25 is turned on, the processing unit 22 acquires position information from the position calculation unit 23 at predetermined time intervals (step S120), and further acquires measurement information (line image) from the image sensor 44. Then, the shape calculation unit 24 acquires the shape information of the object 51 to be measured (step S130), and stores the shape information in the storage unit 26 each time (step S140). Since the processing unit 22 repeats this process until the operation switch 25 is turned off, the shape information of the measured object 51 in the range scanned by the probe 12 while the operation switch 25 is turned on is stored in the storage unit 26. (Step S150). When the operation switch 25 is turned off by the measurer, the processing unit 22 turns off the light source 41 (step S160), reads the shape information acquired so far from the storage unit 26, and scans the object 51 to be measured. A three-dimensional image of the range is generated (step S170) and output to the display unit 30 (step S180). In this way, by displaying the three-dimensional image as the measurement result on the display unit 30, whether or not the shape information can be appropriately acquired, which part of the measured object 51 the shape information can be acquired, etc. The measurer can confirm appropriately by visual inspection.

  As described above, the shape measuring apparatus 100 according to the present embodiment is provided with the drive unit 15 in each of the joint portions 11b, and is configured to assist the rotation operation of the joint portion 11b according to the operation of the measurer. ing. Below, the assistance method is demonstrated.

[Operation load reduction control]
As described above, the torque sensor 27 is attached to each of the joint portions 11b, and is configured to detect torque information applied to the joint portions 11b. The torque information output from the torque sensor 27 is input to the torque calculation unit 28, and the amount and direction of torque applied to each joint portion 11b are obtained. Further, the driving force assisting unit 29, when the torque amount and direction are output by the torque calculating unit 28, rotates and torques for operating the driving unit 15 to rotate the arm unit 11a or the probe 12 in that direction. Is calculated. And the process part 22 controls the action | operation of each drive part 15 so that it may become the rotation direction and torque which were calculated by the drive force auxiliary | assistant part 29. FIG. The driving force assisting unit 29 calculates the rotational direction and the torque amount for feedback control of the driving unit 15 so that the torque amount output from the torque calculating unit 28 becomes zero. Thus, by detecting the torque applied to the joint portion 11b and operating the drive unit 15 so as to assist the measurement operation of the measurement shot, the load on the measurer who operates the probe 12 can be reduced. Time measurement operation becomes possible.

[Constant speed control]
Next, by moving the probe 12 along the measurement target surface of the object to be measured 51, when measuring the shape of the measurement target surface, the probe 12 is moved at a constant speed to accurately measure the measurement data. Control for this will be described with reference to FIG.

  When detecting that the operation switch 25 is turned on (step S200), the processing unit 22 monitors whether a predetermined time has passed (step S210). During the predetermined time, the driving force assisting unit 29 and the processing unit 22 perform the above-described control for reducing the operation load, whereby the load on the measurer who operates the probe 12 can be reduced. It should be noted that the reason for waiting until the predetermined time elapses is a period in which a large force is required when the probe 12 starts moving along the measurement target surface of the object to be measured 51 and is accelerated. This is to wait until the moving speed of the probe 12 reaches a predetermined speed.

  If it is determined in step S210 that a predetermined time has elapsed from the start of measurement, the processing unit 22 causes the driving force assisting unit 29 to calculate the rotation direction and torque for operating the driving unit 15. Specifically, the driving force assisting unit 29 first acquires the position information from the position calculating unit 23 and moves the movement vector (moving direction and speed) of the probe 12 (at the distal end portion of the arm portion 11a located closest to the distal end side). ) Is calculated and acquired (step S220). Further, the range of the moving speed that is optimal for acquiring the measurement information by scanning the line light is calculated and acquired (step S230). Further, it is determined whether or not the moving speed is within the optimum moving speed range among the moving vectors. If the moving speed is out of this range, a vector for correcting the moving vector so that the optimum speed is obtained. Is calculated (step S240). For example, when the moving speed of the probe 12 is faster than the optimum moving speed range, a vector in the direction to be slowed down is calculated. Finally, when this correction vector is decomposed into the respective rotation directions and torques of the plurality of joint portions 11b and passed to the processing unit 22, each of the drive units 15 is adjusted by the processing unit 22 so as to obtain the rotation direction and torque. The operation is controlled (step S240). And the process part 22 repeats the process of step S220 to S240 until the operation switch 25 is turned off (step S250). In this way, by operating the drive unit 15 so that the moving speed of the probe 12 is within a predetermined speed, data irregularity of the shape information acquired by the shape calculation unit 24 is reduced, and the measurement result is stabilized. Can do.

[Directivity control]
Finally, a method for improving the accuracy of measurement information by controlling the moving direction of the probe 12 to be an optimum direction in consideration of the directivity of the optical sensor 40 provided in the probe 12 will be described. . In this directivity control, not only the speed but also the optimum moving direction is taken into consideration in the calculation of the optimum vector in step S230 described above. That is, as described with reference to FIG. 3, the optical sensor 40 irradiates the measured object 51 with line light extending in the y-axis direction to acquire shape information. In contrast, when it is moved in a direction (x-axis direction) orthogonal to the direction in which the line light extends, shape information can be acquired most efficiently. Therefore, the driving force assisting unit 29 acquires the position information from the position calculating unit 23, detects the direction of the probe 12, and sets the direction of the optimal vector so that the probe 12 moves in the direction orthogonal to the line light. decide. Further, when measurement information (line image) measured by the image sensor 44 of the optical sensor 40 moves in a direction away from the imaging range of the image sensor 44 (moves outward from the center of the image sensor 44). In this case, for example, when the measurement target surface of the object 51 to be measured changes in a direction orthogonal to the scanning direction (the z-axis direction in FIG. 3 or the distance between the object surface and the cut surface) In response to this, the direction of the optimum vector is determined so that the line image moves to a substantially central portion of the image sensor 44.

  When the optimum vector is determined in this way, the processing unit 22 controls each of the driving units 15 with the rotation direction and torque output from the driving force assisting unit 29, and thus, among the forces that the measurer moves the probe 12, The force in the y-axis direction is canceled and the probe 12 moves in the x-axis direction, and the probe 12 can be moved so that the line light is irradiated at an optimum distance and direction with respect to the measured object 51. Therefore, the measurement accuracy of shape information can be improved. Note that the optimum vector may be determined so as to fall within the range of the optimum inclination direction in consideration of the inclination direction in which the line light is irradiated.

  Note that the operation load reduction control, constant speed control, and directivity control described above may be executed at the same time (controlled by the processing procedure shown in FIG. 5). The control combination may be configured to allow the measurer to select from an input device (not shown) connected to the control unit 20. Moreover, the line light irradiated to the to-be-measured object 51 can also be made using a slit.

11 Movement mechanism part 11a Arm part 11b Joint part (connection part)
DESCRIPTION OF SYMBOLS 12 Probe 15 Drive part 20 Control part 21 Encoder (angle information detection part) 27 Torque sensor (torque detection part)
DESCRIPTION OF SYMBOLS 40 Optical sensor 41 Light source 42 Line light formation optical system 43 Image pick-up optical system 44 Image pick-up element 51 Object to be measured 100 Shape measuring apparatus

Claims (7)

A probe that scans an object to be measured by an optical sensor in a non-contact manner and outputs measurement information of the shape of the object to be measured;
A moving mechanism portion that has two or more connecting portions that rotatably connect the arm portion and between the arm portions or the arm portion and the probe, and supports the probe so as to be movable within a predetermined space. When,
An angle information detection unit that is provided in each of the connection units and detects angle information between the arm units connected by the connection unit or between the arm unit and the probe,
A drive unit that is provided in the connection unit and that rotationally drives the one arm unit or the probe that is connected by the connection unit with respect to the other arm unit;
A shape measuring apparatus comprising: a control unit that detects movement of the probe from the angle information and operates the driving unit according to the movement. A torque detector provided in each of the connecting portions, for detecting the magnitude and direction of torque applied to the connecting portion;
The control unit is provided in each connection unit so as to rotate the arm unit or the probe in the same direction as the direction of the torque detected by the torque detection unit provided in the connection unit. The shape measuring apparatus according to claim 1, wherein the driving unit is operated.   The shape measuring apparatus according to claim 1, wherein the control unit operates the driving unit so that a moving speed of the probe is within a predetermined range. The moving mechanism part has three or more connecting parts,
The shape measuring apparatus according to claim 1, wherein the control unit operates the drive unit so that a moving direction of the probe is a predetermined direction. The optical sensor provided in the probe includes a light source, a line light forming optical system that irradiates the object to be measured with light from the light source as line light, and imaging optical that forms an image of reflected light of the line light. A system, and an image sensor that detects an image of the reflected light, and configured to measure the shape of the object to be measured by the image detected by the image sensor,
The shape measuring apparatus according to claim 4, wherein the control unit operates the driving unit so that the probe moves in a direction corresponding to directivity of the optical sensor.   The shape measuring apparatus according to claim 5, wherein the control unit operates the driving unit so that the probe moves in a direction orthogonal to a direction in which the line light extends along the surface of the object to be measured.   The shape measuring apparatus according to claim 5, wherein the control unit operates the driving unit so that the image of the line light is positioned at a substantially central portion of the imaging element.

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