JP2018028466A - Measuring device and motor control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a measuring device and a motor control method capable of accurately and synchronously controlling optical members.SOLUTION: A measuring device comprises: a distance measuring part 19 that emits distance measuring light and receives reflected distance measuring light so as to perform distance measurement; an optical axis deflecting part 39 that is provided in a common optical path of the distance measuring light and the reflected distance measuring light, and deflects optical axes of the distance measuring light and the reflected distance measuring light at the same deflection angle and in the same direction; an emission direction detecting part 22 that detects the deflection angle and the deflection direction by the optical axis deflecting part 39; and a calculation control part 27. The optical axis deflecting part 39 includes: a pair of disc-shaped optical prisms that are arranged adjacently and in parallel to each other, and can rotate separately from each other; a pair of motors that rotate the respective optical prisms; and encoders that detect rotation angles of the respective motors. The calculation control part 27 is constructed: to control the motors based on respective torque values and target rotation angles that are preset so that the optical prisms reciprocatively rotate; to detect, for each motor, a coincidence between a detected rotation angle detected by the corresponding encoder and a target rotation angle; and to correct the torque values based on time difference in detection.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a measuring apparatus and a motor control method capable of measuring a three-dimensional shape of a measurement object.

  As a measuring machine for measuring the three-dimensional coordinates of the measurement object, for example, there are a total station and a three-dimensional laser scanner. Some total stations have a motor for automatic collimation, and after installation at the measurement position, the target is automatically collimated and the distance measurement light is emitted for measurement. Yes. The three-dimensional laser scanner scans a measurement object with distance measuring light at high speed and measures the three-dimensional shape of the measurement object in a short time.

  When the ranging light is deflected toward the measurement object, the ranging light may be deflected using an optical member. In this case, in order to accurately deflect the distance measuring light, it is necessary to control a motor that drives the optical member so that the optical member is accurately synchronized.

JP 2014-85134 A JP 2008-268004 A

  The present invention provides a measuring apparatus and a motor control method that can accurately and optically control optical members.

  The present invention provides a distance measuring unit that emits distance measuring light, receives reflected distance measuring light and performs distance measurement, and a common optical path of the distance measuring light and the reflected distance measuring light. An optical axis deflecting unit that deflects the optical axis of light in the same declination and the same direction, an exit direction detecting unit that detects the declination and deflection direction by the optical axis deflecting unit, and an arithmetic control unit; The optical axis deflection unit has a pair of overlapping disk-shaped optical prisms that can rotate independently of each other, a pair of motors that rotate the optical prisms, and an encoder that detects the rotation angle of the motors, The arithmetic control unit controls the motor based on a preset torque value and a target rotation angle so that the optical prism reciprocates, and coincides with the detected rotation angle detected by the encoder and the target rotation angle. Is detected for each motor, and the torque value is based on the detection time difference. Those of the configured measurement device as to fix.

  Further, in the present invention, the calculation control unit calculates a torque correction value based on the time difference, and based on the torque correction value, the motor control unit detects a match between the detected rotation angle and the target rotation angle. The present invention relates to a measuring device that corrects the torque value so as to weaken it.

  According to the present invention, the calculation control unit calculates a torque correction value based on the time difference, and based on the torque correction value, the coincidence between the detected rotation angle and the target rotation angle is detected with respect to the motor. The present invention relates to a measuring device that is modified to increase the torque value.

  Further, in the present invention, the calculation control unit calculates an overrun amount of the motor from a rotation angle at the time of reversal detected when the motor is reversed and a preset reference target rotation angle, and calculates the overrun amount. The present invention relates to a measuring apparatus for correcting the target rotation angle so as to reduce the reversal rotation angle.

  The present invention also provides a measuring apparatus main body that houses the distance measuring section, the optical axis deflecting section, the emission direction detecting section, and the calculation control section, and rotating the measuring apparatus main body in the vertical and horizontal directions. A measuring apparatus comprising: a support section that supports the measurement apparatus; a rotation driving section that rotates the measurement apparatus main body in the vertical direction and the horizontal direction; and an angle detector that detects the vertical and horizontal angles of the measurement apparatus main body. Is.

  According to the present invention, the optical prism is formed at a central portion, and is formed at a distance measuring optical axis deflecting portion for deflecting the distance measuring light at a required declination and a required direction, and at the outer peripheral portion. The present invention relates to a measuring apparatus having a reflected distance measuring optical axis deflecting section for deflecting reflected distance measuring light in the same direction and in the same direction as the deflecting section.

  The present invention also relates to a measuring apparatus in which the optical prism is a Fresnel prism.

  Furthermore, the present invention is a motor control method for performing reversal control of a motor, wherein a time difference is calculated when the rotation angles of a pair of motors match a target rotation angle, and the motor is controlled based on the time difference. The present invention relates to a motor control method for correcting a torque value for driving.

  According to the present invention, the distance measuring light is provided in the common optical path of the distance measuring light and the reflected distance measuring light and the distance measuring unit that emits the distance measuring light, receives the reflected distance measuring light, and performs distance measurement. An optical axis deflecting unit that deflects the optical axis of the distance measuring light with the same declination and the same direction, an emission direction detecting unit that detects the declination and deflection direction by the optical axis deflecting unit, and an arithmetic control unit The optical axis deflecting unit includes a pair of overlapping disk-shaped optical prisms that can rotate independently, a pair of motors that rotate the optical prisms, and an encoder that detects the rotation angle of the motors. The arithmetic control unit controls the motor based on a preset torque value and a target rotation angle so that the optical prism reciprocates, and detects a detected rotation angle detected by the encoder, and the target rotation angle. Is detected for each motor, and the torque is detected based on the detection time difference. Since the optical prism can be synchronized and rotated accurately, the deflection direction set by the distance measuring light can be matched with the actual deflection direction to obtain an accurate measurement result. In addition, the synchronous rotation can be accurately performed without considering the individual differences of the motors, and workability can be improved.

  According to the present invention, there is also provided a motor control method for performing reversal control of a motor, wherein a time difference is calculated when the rotation angles of a pair of motors coincide with a target rotation angle, and the motor is based on the time difference. Since the torque value for driving the motor is corrected, the motor can be accurately rotated synchronously regardless of individual differences between the motors, and the workability can be improved. .

It is a front view which shows the measuring apparatus which concerns on the Example of this invention. It is the schematic which shows the optical system of this measuring apparatus. It is an enlarged view of the optical axis deflection | deviation part of this optical system. (A)-(C) are explanatory drawings which show the effect | action of an optical axis deflection | deviation part. It is a control figure explaining the control method of the motor at the time of rotating an optical prism synchronously. (A) (B) is explanatory drawing explaining the overrun which arises when a motor is rotated. It is a control figure explaining the control method which carries out synchronous rotation of the motor at the time of rotating an optical prism synchronously. It is a control figure explaining the control method which prevents the overrun of the motor at the time of rotating an optical prism synchronously.

  Embodiments of the present invention will be described below with reference to the drawings.

  First, referring to FIGS. 1 and 2, a measuring apparatus according to an embodiment of the present invention will be described.

  The measuring device 1 is a total station having a tracking function, for example, and is installed on a tripod (not shown). The measuring device 1 includes a measuring device main body 2, a rack portion 3, a pedestal portion 4, and a survey base 5.

  The said rack part 3 is the concave shape which has a recessed part, and the said measuring apparatus main body 2 is accommodated in the recessed part. The measuring device main body 2 is supported by the rack 3 via a vertical rotation shaft 6 and is rotatable in the vertical direction around the vertical rotation shaft 6.

  A vertical driven gear 7 is fitted on the end of the vertical rotary shaft 6. The vertical driven gear 7 meshes with the vertical drive gear 8, and the vertical drive gear 8 is fixed to the output shaft of the vertical drive motor 9. The measuring device body 2 is rotated in the vertical direction by the vertical drive motor 9.

  In addition, a vertical rotation angle detector 11 (for example, an encoder) that detects a vertical angle (an angle in a rotation direction around the vertical rotation shaft 6) between the vertical rotation shaft 6 and the measuring apparatus main body 2 is provided. Is provided. The vertical rotation angle detector 11 detects a relative rotation angle in the vertical direction of the measuring device main body 2 with respect to the rack part 3.

  A left and right rotary shaft 12 protrudes from the lower surface of the rack portion 3, and the left and right rotary shaft 12 is rotatably fitted to the pedestal portion 4 via a bearing (not shown). The rack portion 3 is rotatable in the left-right direction around the left-right rotation shaft 12.

  A left and right driven gear 13 is fixed to the pedestal 4 so as to be concentric with the left and right rotating shaft 12. A left / right drive motor 14 is provided on the rack 3, and a left / right drive gear 15 is fixed to an output shaft of the left / right drive motor 14. The left and right drive gear 15 meshes with the left and right driven gear 13. The rack 3 is rotated in the left-right direction by the left-right drive motor 14.

  Further, a left / right rotation angle detector 16 (for example, an encoder) that detects a left / right angle (an angle in a rotation direction around the left / right rotation shaft 12) is provided between the left / right rotation shaft 12 and the pedestal portion 4. Is provided. The left / right rotation angle detector 16 detects a relative rotation angle in the left / right direction of the rack part 3 with respect to the pedestal part 4.

  The pedestal 4 is provided on the survey base 5, and the survey base 5 is installed on a tripod (not shown). The surveying base 5 has an automatic leveling mechanism and functions as a leveling unit that performs automatic leveling of the measurement apparatus main body 2.

  The measurement apparatus main body 2 can be directed in a desired direction by the cooperation of the vertical drive motor 9 and the left / right drive motor 14. In addition, the support part of the measurement apparatus main body 2 is configured by the frame part 3 and the pedestal part 4. The vertical drive motor 9 and the left / right drive motor 14 constitute a rotational drive unit of the measurement apparatus main body 2.

  In the measurement apparatus main body 2, a ranging light emitting unit 17, a light receiving unit 18, a ranging unit 19, an imaging unit 21, an emission direction detecting unit 22, a motor driver 23, a tracking light emitting unit 24, and a tracking light receiving unit 25. The tracking unit 26 and the calculation control unit 27 which is a measurement control unit are housed and integrated. The measuring device body 2 is provided with an operation unit 28 and a display unit 29. The display unit 29 may be a touch panel and may be used as the operation unit 28.

  The distance measuring light emitting unit 17 has an emission optical axis 31, and a light emitting element 32, for example, a laser diode (LD) is provided on the emission optical axis 31. A projection lens 33 is provided on the emission optical axis 31. Further, the first reflecting mirror 34 as a deflection optical member provided on the emission optical axis 31 and the second reflection mirror 36 as a deflection optical member provided on a light receiving optical axis 35 (described later) The emission optical axis 31 is deflected so as to coincide with the light receiving optical axis 35. The first reflecting mirror 34 and the second reflecting mirror 36 constitute an exit optical axis deflecting unit.

  The first reflecting mirror 34 has a wavelength selection function, and is, for example, a beam splitter having an optical characteristic of reflecting distance measuring light and transmitting tracking light described later.

  The light receiving unit 18 includes the light receiving optical axis 35, and reflected distance measuring light from a retroreflective target such as a measurement object, a prism, or a reflecting mirror is incident on the light receiving unit 18.

  A light receiving element 37, for example, a photodiode (PD) is provided on the light receiving optical axis 35, and an imaging lens 38 is provided. The imaging lens 38 images the reflected distance measuring light on the light receiving element 37. The light receiving element 37 receives reflected distance measuring light and emits a light receiving signal. The received light signal is input to the distance measuring unit 19.

  Further, an optical axis deflection unit 39 is disposed on the objective side of the imaging lens 38 on the light receiving optical axis 35 (that is, the emission optical axis 31). Hereinafter, the optical axis deflection unit 39 will be described with reference to FIG.

  The optical axis deflecting unit 39 includes a pair of optical prisms 41a and 41b. Each of the optical prisms 41a and 41b has a disk shape, and is disposed on the light receiving optical axis 35 so as to be orthogonal to the light receiving optical axis 35. The optical prisms 41a and 41b overlap and are disposed in parallel. Fresnel prisms are preferably used as the optical prisms 41a and 41b, respectively, in order to reduce the size of the apparatus.

  The central portion of the optical axis deflecting portion 39 is a distance measuring optical axis deflecting portion 39a that is a first optical axis deflecting portion that transmits distance measuring light, and a portion other than the central portion transmits reflected distance measuring light. It is a reflection distance measuring optical axis deflecting unit 39b which is a second optical axis deflecting unit.

  The Fresnel prism used as the optical prisms 41a and 41b includes prism elements 42a and 42b and a large number of prism elements 43a and 43b formed in parallel, and has a plate shape. The prism elements 42a and 42b and the prism elements 43a and 43b have the same optical characteristics.

  The prism elements 42a and 42b constitute the distance measuring optical axis deflecting unit 39a, and the prism elements 43a and 43b constitute the reflected distance measuring optical axis deflecting unit 39b.

  The Fresnel prism may be manufactured from optical glass, but may be molded from an optical plastic material. An inexpensive Fresnel prism can be manufactured by molding with an optical plastic material.

  The optical prisms 41a and 41b are arranged to be independently rotatable around the light receiving optical axis 35, respectively. The optical prisms 41a and 41b are independently controlled in the rotation direction, rotation amount, and rotation speed, thereby deflecting the exit optical axis 31 of the distance measuring light to be emitted in an arbitrary direction and receiving the reflected light. The light receiving optical axis 35 of the distance measuring light is deflected so as to be parallel to the emission optical axis 31.

  The external shapes of the optical prisms 41a and 41b are circular with the light receiving optical axis 35 as the center, and the optical prisms 41a and 41b can obtain a sufficient amount of light in consideration of the spread of reflected distance measuring light. The diameter is set.

  A ring gear 44a is fitted on the outer periphery of the optical prism 41a, and a ring gear 44b is fitted on the outer periphery of the optical prism 41b.

  A drive gear 45a meshes with the ring gear 44a, and the drive gear 45a is fixed to the output shaft of the motor 46a. Similarly, a drive gear 45b meshes with the ring gear 44b, and the drive gear 45b is fixed to the output shaft of the motor 46b. The motors 46 a and 46 b are electrically connected to the motor driver 23.

  As the motors 46a and 46b, a motor capable of detecting a rotation angle or a motor that rotates according to a drive input value, for example, a pulse motor is used. Or you may detect the rotation amount of a motor using the rotation angle detector which detects the rotation amount (rotation angle) of a motor, for example, an encoder. The rotation amounts of the motors 46a and 46b are respectively detected, and the motors 46a and 46b are individually controlled by the motor driver 23.

  The drive gears 45a and 45b and the motors 46a and 46b are provided at positions that do not interfere with the distance measuring light emitting unit 17, for example, below the ring gears 44a and 44b.

  The light projecting lens 33, the distance measuring optical axis deflecting unit 39a, etc. constitute a light projecting optical system, and the reflection distance measuring optical axis deflecting unit 39b, the imaging lens 38, etc. constitute a light receiving optical system. .

  The distance measuring unit 19 controls the light emitting element 32 to emit a laser beam as distance measuring light. The exit optical axis 31 is deflected by the prism elements 42a and 42b (the distance measuring optical axis deflecting unit 39a) so that the distance measuring light is directed toward the measurement point.

  The reflected distance measuring light reflected from the measurement object is incident on the light receiving section 18 via the prism elements 43a and 43b (the reflected distance measuring optical axis deflecting section 39b) and the imaging lens 38, and the light receiving element. 37 receives light. The light receiving element 37 sends a light receiving signal to the distance measuring unit 19, and the distance measuring unit 19 measures the distance of a measurement point (a point irradiated with distance measuring light) based on the light receiving signal from the light receiving element 37. Do.

  The imaging unit 21 is a camera having a field angle of 50 °, for example, and acquires image data including a measurement object. The imaging unit 21 has an imaging optical axis 47 in which the measuring apparatus main body 2 extends in a horizontal direction in a horizontal posture, and the imaging optical axis 47 and the emission optical axis 31 are set to be parallel to each other. Yes. The distance between the imaging optical axis 47 and the exit optical axis 31 is also a known value.

  The image pickup device 48 of the image pickup unit 21 is a CCD or CMOS sensor that is an aggregate of pixels, and the position of each pixel on the image device can be specified. For example, the position of each pixel in the coordinate system with the imaging optical axis 47 as the origin is specified.

  The injection direction detector 22 detects the rotation angle of the motors 46a and 46b by counting the drive pulses input to the motors 46a and 46b. Alternatively, the rotation angles of the motors 46a and 46b are detected based on signals from encoders 58a and 58b (described later). The emission direction detector 22 calculates the rotational positions of the optical prisms 41a and 41b based on the rotational angles of the motors 46a and 46b. Further, the exit direction detection unit 22 calculates the deflection angle and exit direction of the distance measuring light based on the refractive index and the rotational position of the optical prisms 41a and 41b, and the calculation result is input to the calculation control unit 27. .

  An encoder may be provided for each of the optical prisms 41a and 41b, and the rotational positions of the optical prisms 41a and 41b may be calculated based on the detection results of the encoders.

  The tracking light emitting section 24 has a tracking optical axis 49, and a light emitting element 51, for example, a laser diode (LD) that emits tracking light having a wavelength different from the distance measuring light is provided on the tracking optical axis 49. ing. A light projecting lens 52 is provided on the tracking optical axis 49. Further, the first reflecting mirror 34 as a deflection optical member is provided on the tracking optical axis 49. The emission of the tracking light by the light emitting element 51 is controlled by the tracking unit 26.

  The tracking light transmitted through the first reflecting mirror 34 coincides with the emission optical axis 31 deflected by the first reflecting mirror 34. Further, the tracking light is reflected by the second reflecting mirror 36 so as to coincide with the light receiving optical axis 35 (that is, the emission optical axis 31).

  The tracking light receiving unit 25 includes a third reflecting mirror 53 that is a deflecting optical member and has a wavelength selection function, a condensing lens 54, a fourth reflecting mirror 55 that is a deflecting optical member, and a tracking light receiving element 56. ing.

  The third reflecting mirror 53 is provided on the light receiving optical axis 35 and has an optical characteristic of reflecting reflected tracking light and transmitting reflected ranging light having different wavelengths. The tracking light receiving unit 25 has a tracking light receiving optical axis 57 branched from the light receiving optical axis 35 by the third reflecting mirror 53. The fourth reflecting mirror 55 and the tracking light receiving element 56 are It is provided on the tracking light receiving optical axis 57. The condenser lens 54 is disposed between the third reflecting mirror 53 and the fourth reflecting mirror 55.

  When the target is detected and tracked, a retroreflecting mirror such as a prism is used as the measurement object. Reflected tracking light reflected by a prism (not shown) passes through the optical axis deflecting unit 39, is reflected by the third reflecting mirror 53, is collected by the condenser lens 54, and is collected by the fourth reflecting mirror. 55 is deflected on the tracking light receiving optical axis 57 and received by the tracking light receiving element 56. The tracking light receiving element 56 is a CCD or CMOS sensor that is an aggregate of pixels, and each pixel can be positioned on the image element. The tracking light receiving element 56 receives reflected tracking light and emits a light reception signal based on the light received on the tracking light receiving element 56. The received light signal is input to the tracking unit 26.

  The tracking unit 26 detects a prism based on reception of reflected tracking light on the tracking light receiving element 56 and calculates a difference between the center of the tracking light receiving element 56 and the position of the prism. The calculation result is input to the calculation control unit 27.

  The calculation control unit 27 includes an input / output control unit, a calculator (CPU), a storage unit, and the like. In the storage unit, a ranging program for controlling the ranging operation, a detection program for detecting a target described later, a tracking program for controlling the tracking operation, and for causing the motor driver 23 to control driving of the motors 46a and 46b. Prism control program, main body control program for controlling the driving of the vertical drive motor 9 and the left and right drive motor 14, the calculation result of the emitting direction of the distance measuring light from the emission direction detecting unit 22, the vertical rotation angle detection Direction angle calculation program for calculating the direction angle (horizontal angle, vertical angle) of distance measuring light based on the detection results of the detector 11 and the left / right rotation angle detector 16, and the display unit 29 displays image data, distance measurement data, etc. A program such as an image display program is stored. Further, the storage unit stores distance measurement data, image data, rotational position data of the optical prisms 41a and 41b, set value data for controlling the motors 46a and 46b, and the like.

  Next, the measurement operation by the measurement apparatus 1 will be described with reference to FIGS. 4 (A) to 4 (C). In FIG. 4A, the prism elements 42a and 42b and the prism elements 43a and 43b are shown separately for the optical prisms 41a and 41b for the sake of simplicity. Further, the prism elements 42a and 42b and the prism elements 43a and 43b shown in FIG. 4A are in a state where the maximum declination is obtained. The minimum declination is a position where either one of the optical prisms 41a and 41b is rotated by 180 °, the declination is 0 °, and the optical axis of the emitted laser beam (ranging light) is the emission. Parallel to the optical axis 31. The prism elements 42a and 42b can scan the measurement object or the measurement object area with distance measuring light within a range of ± 20 °, for example.

  Distance measuring light is emitted from the light emitting element 32, and the distance measuring light is converted into a parallel light beam by the light projecting lens 33, and passes through the distance measuring optical axis deflection unit 39a (the prism elements 42a and 42b) to be measured. Or it injects toward the measurement object area. Here, by passing through the distance measuring optical axis deflecting portion 39a, the distance measuring light is deflected in a required direction by the prism elements 42a and 42b and emitted.

  The reflected distance measuring light reflected by the measurement object or the measurement object area is incident through the reflected distance measuring optical axis deflecting unit 39b (the prism elements 43a and 43b), and is received by the imaging lens 38. It is condensed on the element 37.

  When the reflected distance measuring light passes through the reflected distance measuring optical axis deflecting unit 39b, the optical axis of the reflected distance measuring light is deflected by the prism elements 43a and 43b so as to coincide with the light receiving optical axis 35 ( FIG. 4 (A)).

  Further, by combining the rotational positions of the optical prism 41a and the optical prism 41b, it is possible to deflect the emitted distance measuring light with an arbitrary deflection direction and angle.

  Further, with the positional relationship between the optical prism 41a and the optical prism 41b fixed (with the declination obtained by the optical prism 41a and the optical prism 41b fixed), by the motors 46a and 46b, By rotating the optical prism 41a and the optical prism 41b integrally, the locus drawn by the distance measuring light transmitted through the distance measuring optical axis deflecting unit 39a becomes a circle centered on the emission optical axis 31.

  Therefore, if the optical axis deflection unit 39 is rotated while emitting a laser beam (ranging light) from the light emitting element 32, the ranging light can be scanned along a circular locus.

  Needless to say, the reflection distance measuring optical axis deflecting unit 39b rotates integrally with the distance measuring optical axis deflecting unit 39a.

  Next, FIG. 4B shows a case where the optical prism 41a and the optical prism 41b are relatively rotated. Assuming that the deflection direction of the optical axis deflected by the optical prism 41a is deflection A and the deflection direction of the optical axis deflected by the optical prism 41b is deflection B, the deflection of the optical axis by the optical prisms 41a and 41b is as follows: As an angle difference θ between the optical prisms 41a and 41b, a combined deflection C is obtained.

  Accordingly, each time the angle difference θ is changed, the distance measuring light can be scanned linearly by rotating the optical axis deflecting unit 39 once and irradiating every rotation. When the angle difference θ is changed, the distance measuring light can be scanned in a concentric multiple circle shape by rotating the distance measuring light in the irradiated state. Further, if the optical prism 41a and the optical prism 41b are rotated in the opposite directions at the same speed, the distance measuring light can be scanned in a straight line in the combined deflection C direction.

  Further, as shown in FIG. 4C, if the optical prism 41b is rotated at a rotational speed that is slower than the rotational speed of the optical prism 41a, the distance measurement light rotates while the angle difference θ gradually increases. Therefore, the scanning track of the distance measuring light has a spiral shape.

  Further, by individually controlling the rotation direction and rotation speed of the optical prism 41a and the optical prism 41b, the scanning path of the distance measuring light is emitted in the radial direction (scanning in the radial direction) around the exit optical axis 31. Or various scanning states such as horizontal and vertical directions can be obtained.

  As a measurement mode, it is possible to perform distance measurement for a specific measurement point by performing distance measurement with the optical axis deflecting unit 39 fixed for each required deflection angle. Further, the distance measurement data for the measurement points on the scanning locus is obtained by performing distance measurement while changing the deflection angle of the optical axis deflecting unit 39, that is, by performing distance measurement while scanning the distance measurement light. Can be obtained.

  The emission direction angle of each ranging light can be detected by the rotation angle of the motors 46a and 46b and the detection results of the up / down rotation angle detector 11 and the left / right rotation angle detector 16, and the emission direction angle and the distance measurement data By associating, three-dimensional ranging data can be acquired.

  Further, as described above, the measuring apparatus 1 includes the imaging unit 21, and an image acquired by the imaging unit 21 is displayed on the display unit 29.

  Here, the angle of view of the imaging unit 21 is, for example, 50 °, and the deflection range by the optical prisms 41a and 41b is, for example, ± 20 °. Therefore, the measurement range of the distance measuring unit 19 is the imaging of the imaging unit 21. It almost matches the range. Therefore, the measurer can easily identify the measurement range visually and can search for the measurement object from the image displayed on the display unit 29 or select the measurement object. There is no need to apply.

  The angle of view of the imaging unit 21 and the deflection range by the optical prisms 41a and 41b are not limited to those described above. For example, the measurement range of the distance measuring unit 19 and the imaging range of the imaging unit 21 are complete. You may make it correspond to.

  When the measurement object is selected, the optical prisms 41a and 41b are rotated so that the distance measuring light is deflected toward the measurement object. When the measurement object is outside the imaging range of the imaging unit 21, the vertical drive motor 9 and the left and right drive motor 14 are set so that the measurement target is located within the imaging range of the imaging unit 21. Drive.

  Since the emission optical axis 31 and the imaging optical axis 47 are parallel and both optical axes are in a known relationship, the arithmetic control unit 27 is configured to display the image center and the emission on the image acquired by the imaging unit 21. The optical axis 31 can be matched. Further, the arithmetic control unit 27 can identify the measurement point on the image based on the emission direction angle by detecting the emission direction angle of the distance measuring light. Therefore, the three-dimensional distance measurement data of the measurement point can be easily associated with the image acquired by the imaging unit 21, and the image acquired by the imaging unit 21 can be an image with three-dimensional data.

  In addition, the measuring device 1 includes the tracking unit 26. Tracking light is emitted from the light emitting element 51, and the tracking light is converted into a parallel light beam by the light projecting lens 52 and passes through the distance measuring optical axis deflecting unit 39 a (the prism elements 42 a and 42 b). The light is emitted toward a retroreflective target such as a prism or a reflecting mirror. Here, by passing through the distance measuring optical axis deflecting unit 39a, the tracking light is deflected in a required direction by the prism elements 42a and 42b and emitted.

  The reflected tracking light reflected by the target is incident through the reflection distance measuring optical axis deflecting unit 39b (the prism elements 43a and 43b), and the imaging lens 38, the third reflecting mirror 53, and the condensing light. The light is condensed on the tracking light receiving element 56 by the lens 54 and the fourth reflecting mirror 55.

  The tracking unit 26 detects a target based on reception of reflected tracking light on the tracking light receiving element 56 and calculates a difference between the center of the tracking light receiving element 56 and the position of the target. The calculation result is input to the calculation control unit 27.

  The calculation control unit 27 controls driving of the motors 46a and 46b based on the calculation result in the tracking unit 26. The calculation control unit 27 rotates the optical prisms 41 a and 41 b so that the reflected tracking light from the target is received at the center of the tracking light receiving element 56. As a result, the measuring apparatus main body 2 keeps the target tracking by causing only the tracking light to follow the movement of the target in a stationary state.

  Needless to say, when the tracking range by the optical axis deflecting unit 39 is exceeded, the vertical drive motor 9 and the left and right drive motor 14 are driven to rotate the measuring device body 2 toward the target. Absent.

  Hereinafter, in the case where a limited part of the measurement object is intensively measured, the optical prism 41a and the optical prism 41b are rotated back and forth at high speed, and the part is scanned back and forth with distance measuring light. The inversion control of the motors 46a and 46b will be described.

  FIG. 5 is a basic control diagram when the reversal control of the motors 46a and 46b is performed, and shows a case where the torque values and rotation angles of the motors 46a and 46b are fixed values.

  When a signal a which is an instruction for a rotation direction, for example, a forward rotation and a signal b which is a preset torque value are input from the arithmetic control unit 27 to the motor driver 23a, the motor driver 23a is input. Based on the signals a and b, the motor 46a is rotated.

  The rotation angle of the motor 46a is detected in real time by the encoder 58a, and a signal c having the detected rotation angle is input to the determination unit 59a.

  A predetermined target rotation angle at the time of forward rotation is input from the calculation control unit 27 to the determination unit 59a as a signal d. The determination unit 59a determines whether the detected rotation angle from the encoder 58a matches the target rotation angle from the calculation control unit 27, and when the detected rotation angle and the target rotation angle match, The rotation completion signal e is output to the arithmetic control unit 27.

  When the rotation completion signal e is input, the arithmetic control unit 27 outputs a signal a that is a rotation instruction (reverse instruction) in a direction opposite to the previous direction and a signal b that is a reverse rotation torque value. Output to the motor driver 23a.

  The above process is repeated until the measurement of the measurement object is completed and the reversal control of the motor 46a is completed. Further, by performing the above processing, the reciprocating operation can be performed with the upper limit of the response speed of the motors 46a and 46b. Further, by repeating the above process, high-speed scanning can be performed for a narrow scanning range.

  The reversing control for the motor 46b is the same as the reversing control for the motor 46a, and the description is omitted.

  In FIG. 5, the determination units 59 a and 59 b are described as independent components, but actually the determination units 59 a and 59 b are part of the arithmetic control unit 27.

  FIG. 6A shows a part of the rotation range 61a of the motor 46a, and the reversal target positions 62a and 62b and the rotation trajectory to the reversal target positions 62a and 62b when the motor 46a is reciprocally rotated. 63a and 63b are shown. FIG. 6B shows a part of the rotation range 61b of the motor 46b. When the motor 46b is reciprocated, the reversal target positions 64a and 64b and the reversal target positions 64a and 64b are rotated. The locus | trajectory 65a, 65b is shown. Since the motor 46b is controlled in the same manner as the motor 46a, FIG. 6 (A) will be described below.

  As shown in FIG. 6A, when the rotation of the motor 46a is stopped at the reverse target position 62a, an overrun 66a occurs, and when the rotation of the motor 46a is stopped at the reverse target position 62b, Overrun 66b occurs. Therefore, the position where the rotation of the motor 46a is actually reversed is a position rotated by the overruns 66a and 66b from the reversal target positions 62a and 62b. That is, the rotation amount of the motor 46a is larger than the set rotation amount by the overruns 66a and 66b.

  The overruns 66a and 66b vary depending on the weight of the motor 46a, the rotational moment, the spread of grease on the bearing portion, and the like. Further, the rotational speed of the motor 46a also changes depending on the weight of the motor 46a and the spread of grease on the bearing portion. Therefore, the change is not uniform due to individual differences due to manufacturing errors. Further, even during the driving of the motor 46a, a change occurs due to an environmental change such as a temperature change and a humidity change. Therefore, it is difficult to grasp and control the rotational speeds of the overruns 66a and 66b and the motor 46a.

  On the other hand, when an overrun occurs in the motors 46a and 46b, or when the rotation speeds are different, the synchronous rotation of the optical prisms 41a and 41b is shifted, and the scanning shape of the set distance measuring light and the reciprocation are set. There may be a difference between the length and the actual scanning shape of the distance measuring light and the reciprocating length, and an accurate measurement result may not be obtained.

  Therefore, in order to obtain an accurate measurement result by the measurement apparatus 1, it is necessary to synchronize the rotation of the optical prisms 41a and 41b accurately and to rotate so as not to cause an overrun.

  Hereinafter, the control of the motors 46a and 46b for accurately synchronizing and rotating the optical prisms 41a and 41b and preventing overrun will be described.

  FIG. 7 is a control diagram when reversing control is performed in which the motors 46a and 46b are accurately rotated synchronously, and shows a case where the torque value is a variable value and the rotation angle is a fixed value.

  When the calculation control unit 27 receives the signal a that is an instruction of the rotation direction and the signal b that is a preset torque value to the motor driver 23a, the motor driver 23a receives the input rotation instruction. The motor 46a is rotated based on a preset torque value.

  The rotation angle of the motor 46a is detected in real time as a signal c by the encoder 58a, and the detected rotation angle is input to the determination unit 59a.

  The determination unit 59a determines whether the detected rotation angle from the encoder 58a matches the target rotation angle (signal d) from the arithmetic control unit 27, and the detected rotation angle matches the target rotation angle. At this point, a rotation completion signal e is output to the arithmetic control unit 27.

  Similarly, when a rotation direction instruction (signal a) and a preset torque value (signal b) are input from the arithmetic control unit 27 to the motor driver 23b, the motor driver 23b is input. The motor 46b is rotated based on the rotation instruction and the torque value.

  The rotation angle of the motor 46b is detected in real time by the encoder 58b (signal c), and the detected rotation angle is input to the determination unit 59b.

  The determination unit 59b determines whether or not the detected rotation angle from the encoder 58b matches the target rotation angle (signal d) from the calculation control unit 27, and the detected rotation angle and the target rotation angle match. At this point, a rotation completion signal e is output to the arithmetic control unit 27.

  The arithmetic control unit 27 receives one rotation completion signal e out of the rotation completion signal e from the determination unit 59a and the rotation completion signal e from the determination unit 59b, and then receives the other rotation completion signal e. The elapsed time (time difference) until is input is measured.

  For example, when the rotation completion signal e from the determination unit 59a is input first, the calculation control unit 27 calculates a torque correction value for weakening the torque value output to the motor driver 23a based on the time difference. . As for the torque correction value, a data table of the time difference between the rotation completion signals e between the motors 46a and 46b and the torque correction value is prepared in advance, and the torque correction value is calculated from the data table. Also good. Alternatively, the time difference after torque correction may be obtained and the torque correction value may be converged so that the time difference becomes zero.

  When the torque correction value is calculated, the calculation control unit 27 calculates the torque correction value from the signal a which is an instruction (inversion instruction) of the rotation direction opposite to the previous time, and a preset torque value (signal b). A torque value obtained by subtracting (signal f), that is, a torque value obtained by adding a negative torque correction value to a preset torque value is output to the motor driver 23a.

  The motor driver 23a rotates the motor 46a in a direction opposite to the previous time with a weaker driving force than the previous time based on the input rotation instruction and torque value.

  In addition, the motor driver 23b receives a signal a which is an instruction (reverse instruction) in the direction of rotation opposite to the previous time and a torque value (signal b) similar to the previous time, and the motor 46b is turned on the previous time. Rotate in the opposite direction with the same driving force as the previous time.

  The above process is repeatedly executed until the measurement of the measurement object is completed and the reversal control of the motors 46a and 46b is completed.

  The motor 46a to which the rotation completion signal e is input first, that is, the motor 46a whose rotational speed is faster than the motor 46b, is controlled so as to weaken the torque value based on the time difference. Since the rotation speed of the motor 46a can be reduced and the rotation speed of the motor 46a can be matched with the rotation speed of the motor 46b, the rotation completion signals e of the motor 46a and the motor 46b are detected simultaneously or substantially simultaneously. Can do.

  Accordingly, it is possible to perform the reversal control in which the motors 46a and 46b are accurately rotated in synchronization, and the optical prisms 41a and 41b can be rotated in synchronization with each other. The scanning shape of the light can be matched, and an accurate measurement result of the measurement object can be obtained.

  Further, since the correction of the torque value based on the time difference is executed at each reversal timing of the motors 46a and 46b, it is possible to cope with a change in the rotational speed during the driving of the motors 46a and 46b.

  Therefore, even when motors having individual differences such as manufacturing errors and spread of grease are used as the motors 46a and 46b, they can be rotated synchronously accurately. Therefore, even if there is an individual difference or assembly error between the motors 46a and 46b, the synchronous control is performed based on the actual rotation state, so that it is not necessary to consider individual differences and the workability can be improved. .

  In the above, the motor 46a to which the rotation completion signal e is input first is controlled so as to weaken the torque value based on the time difference. However, the motor 46b to which the rotation completion signal e is input later is controlled. On the other hand, the torque value may be increased by subtracting a negative torque correction value (signal f) from a preset torque value (signal b) based on the time difference.

  In this case, the calculation control unit 27 calculates a torque correction value based on the time difference, and a torque value obtained by adding a torque correction value (signal f) to a preset torque value (signal b) is output to the motor driver 23b. The

  In the above description, the torque value is corrected at each reversal timing of the motors 46a, 46b. However, the torque value may be corrected every time the motors 46a, 46b are rotated once.

  FIG. 8 is a control diagram when reverse control is performed so as not to cause overrun in the motors 46a and 46b, and shows a case where the torque value is a fixed value and the rotation angle is a variable value. The reversal control performed on the motor 46b is the same control as that on the motor 46a. Therefore, the case where the reversal control on the motor 46a is performed will be described below.

  When the reversal control is started, first, for example, a forward rotation instruction (signal a) and a preset torque value (signal b) are input from the arithmetic control unit 27 to the motor driver 23a. . The motor driver 23a rotates the motor 46a in the forward direction based on the input rotation instruction and torque value.

  The rotation angle of the motor 46a is detected in real time by the encoder 58a, and the detected rotation angle (signal c) is input to the determination unit 68a. The determination unit 68a determines whether or not the preset target rotation angle (signal d) from the calculation control unit 27 and the detected rotation angle coincide with each other, and detects the detected rotation angle and the target rotation angle. Is output, the rotation completion signal e is output to the arithmetic control unit 27.

  When the rotation completion signal e is input, the arithmetic control unit 27 sends a rotation instruction (inversion instruction) (signal a) in a direction opposite to the previous direction (signal a) and a torque value (signal b) to the motor driver 23a. Output to. At this time, the rotation direction (signal f) of the motor 46a is also output from the arithmetic control unit 27 to the determination unit 68a. The motor driver 23a generates a drive signal g for rotating the motor 46a in the reverse direction based on the input rotation instruction (reverse instruction) and torque value.

  Even when the drive signal g is issued to the motor 46a, the motor 46a rotates (overruns) while decelerating without being reversed by the inertia. Eventually, the motor 46a stops and reverses. Stop reversal of the motor 46a is detected by the encoder 58a, and the detection result is input to the determination unit 68a as a rotation angle during reversal.

  The determination unit 68a uses the detected rotation angle (signal h) when the increase in the detected rotation angle (signal c) from the encoder 58a stops or decreases as the rotation angle at the time of reversal. The difference (signal i) between the rotation angle (signal f) and the reference target rotation angle is calculated. This difference (rotation angle difference) is the amount of overrun.

  The determination unit 68a outputs the overrun amount to the arithmetic control unit 27 together with the rotation completion signal e when the target rotation angle and the detected rotation angle coincide.

  The reference target rotation angle is a reference value for detecting an overrun of the motor 46a, and is always constant. At the time when the control of the motor 46a is started, the target rotation angle and the reference target rotation angle coincide.

  The calculation control unit 27 corrects the target rotation angle so as to reduce the reversal rotation angle by the overrun amount based on the input overrun amount, and calculates a new target rotation angle at the time of forward rotation. The arithmetic control unit 27 outputs a rotation instruction and a torque value in the forward direction opposite to the previous time to the motor driver 23a, and outputs the rotation direction to the determination unit 68a. Note that the calculated new target rotation angle at the time of forward rotation is a value different from the reference target rotation angle.

  In addition, a reverse direction instruction in the forward direction is output from the arithmetic control unit 27, and the rotation angle of the motor 46a when the increase in the detected rotation angle stops or when the rotation direction starts to decrease is actually reversed in the forward direction. The rotation angle at the time of reversal, which is the angle at the time of reversal, is detected by the encoder 58a and input to the determination unit 68a.

  The determination unit 68a calculates the difference between the reference target rotation angle at the time of reverse rotation and the rotation angle at the time of reversal, that is, the overrun amount at the time of reverse rotation, and when the overrun amount matches the target rotation angle and the detected rotation angle Is output to the arithmetic control unit 27 together with the rotation completion signal e. Note that the target rotation angle and the reference target rotation angle at this time coincide with each other.

  The calculation control unit 27 corrects the target rotation angle so as to reduce the reversal rotation angle by the overrun amount based on the input overrun amount, and calculates a new target rotation angle at the reverse rotation. The arithmetic control unit 27 outputs a rotation instruction and a torque value in the reverse direction opposite to the previous time to the motor driver 23a, and outputs the rotation direction to the determination unit 68a. Note that the calculated new target rotation angle at the time of reverse rotation is a value different from the reference target rotation angle.

  The determination unit 68a determines the coincidence between the rotation angle detected by the encoder 58a and the new target rotation angle, calculates the difference (overrun amount) between the rotation angle during reversal and the reference target rotation angle, and outputs a rotation completion signal. e and the overrun amount are output to the arithmetic control unit 27.

  The above process is repeated until the measurement of the measurement object is completed and the reversal control of the motor 46a is completed.

  As described above, in this embodiment, the difference between the preset reference target rotation angle and the actual reversal rotation angle at the time of reversal instruction, that is, the overrun amount is calculated, and the reversal rotation angle by the overrun amount is calculated. The target rotation angle is corrected so as to reduce the rotation, and the control is performed so that the rotation angle at the time of inversion approaches the reference target rotation angle.

  Accordingly, since the overrun when the motors 46a and 46b are driven can be suppressed, the set reciprocating length of the distance measuring light and the actual reciprocating length of the distance measuring light can be matched or substantially matched. The accurate measurement result of the measurement object can be obtained.

  Further, the correction of the target rotation angle is executed at each reversal timing of the motors 46a and 46b, so that it is possible to cope with a change in the amount of overrun during the driving of the motors 46a and 46b.

  Therefore, even for motors with individual differences such as manufacturing errors and the spread of grease on the bearings, or for motors that have changed during driving due to environmental changes, etc., the same processing is performed and overrun is performed. Therefore, it is not necessary to consider individual differences between motors, and workability can be improved.

  In FIG. 8, the determination units 68 a and 68 b are described as independent components, but actually the determination units 68 a and 68 b are part of the arithmetic control unit 27.

  In FIG. 7, the motor 46a and 46b are synchronously rotated with a torque value as a variable value and a rotation angle as a fixed value. In FIG. 8, the motor 46a with a torque value as a fixed value and a rotation angle as a variable value. , 46b is suppressed, but both the torque value and the rotation angle may be variable.

  By making both the torque value and the rotation angle variable, synchronous rotation of the motors 46a and 46b and suppression of overrun can be performed at the same time, and the accuracy and workability of the measurement result can be further improved. .

  In the present embodiment, the case where the control for rotating the motors 46a and 46b and the control for suppressing overrun are applied to the measuring apparatus 1 has been described. However, for example, a processing machine for processing a workpiece with a laser beam. The control of this embodiment can be applied to other devices as long as it is necessary to accurately rotate two motors synchronously and suppress overrun, such as control of the direction of the laser beam. Needless to say. Also, the control of this embodiment can be applied to a hollow brushless motor (direct drive motor), an ultrasonic motor, and the like.

DESCRIPTION OF SYMBOLS 1 Measuring apparatus 2 Measuring apparatus main body 18 Light receiving part 19 Distance measuring part 22 Ejection direction detection part 23 Motor driver 27 Calculation control part 39 Optical axis deflection part 41a, 41b Optical prism 46a, 46b Motor 58a, 58b Encoder 59a, 59b Judgment part 68a 68b Judgment part

Claims (8)

  A distance measuring unit that emits distance measuring light, receives reflected distance measuring light and performs distance measurement, and a common optical path for distance measuring light and reflected distance measuring light. The optical axis deflecting unit for deflecting the optical axis in the same declination and the same direction, the exit direction detecting unit for detecting the declination and the deflection direction by the optical axis deflecting unit, and the arithmetic control unit, The unit includes a pair of overlapping disk-shaped optical prisms that can be independently rotated, a pair of motors that rotate the optical prisms, and an encoder that detects a rotation angle of the motors, and the arithmetic control unit includes: The motor is controlled based on a preset torque value and a target rotation angle so that the optical prism reciprocates and the coincidence between the detected rotation angle detected by the encoder and the target rotation angle is determined for each motor. And the torque value is corrected based on the detection time difference. Configured measuring device.   The calculation control unit calculates a torque correction value based on the time difference, and based on the torque correction value, weakens the torque value for the motor in which the coincidence between the detected rotation angle and the target rotation angle has been previously detected. The measuring device according to claim 1, wherein the measuring device is modified.   The calculation control unit calculates a torque correction value based on the time difference, and based on the torque correction value, increases the torque value for the motor for which the coincidence between the detected rotation angle and the target rotation angle is detected later. The measuring device according to claim 1 to be corrected.   The calculation control unit calculates an overrun amount of the motor from a rotation angle at reversal detected when the motor is reversed and a preset reference target rotation angle, and rotates at the time of reversal based on the overrun amount. The measuring apparatus according to claim 1, wherein the target rotation angle is corrected so as to reduce an angle.   A measuring device main body that houses the distance measuring unit, the optical axis deflecting unit, the emission direction detecting unit, and the calculation control unit, and a support that supports the measuring device main body so as to be rotatable in the vertical and horizontal directions. And a rotation drive unit that rotates the measuring device main body in the up and down direction and the left and right direction, and an angle detector that detects a vertical angle and a left and right angle of the measuring device main body. The measuring apparatus of any one of Claims.   The optical prism is formed at the center, and a distance measuring optical axis deflecting unit that deflects the distance measuring light with a required declination and a required direction, and an outer peripheral part, and is the same as the distance measuring optical axis deflecting unit. The measuring apparatus according to claim 1, further comprising: a reflected distance measuring optical axis deflecting unit that deflects the reflected distance measuring light in the same direction.   The measuring apparatus according to claim 1, wherein the optical prism is a Fresnel prism.   A motor control method for performing reversal control of a motor, which calculates a time difference when a rotation angle of a pair of motors matches a target rotation angle, and drives the motor based on the time difference. Motor control method to correct.

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