JP6783093B2 - measuring device - Google Patents

Description

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

As a measuring machine for measuring the three-dimensional coordinates of the object to be measured, for example, there are a total station and a three-dimensional laser scanner. Some total stations have a motor for automatic collimation, and after installing it at the measurement position, it can automatically collimate the object to be measured and emit distance measurement light to perform measurement. There is. Further, the three-dimensional laser scanner scans the object to be measured with distance measuring light at high speed and measures the three-dimensional shape of the object to be measured in a short time.

When deflecting the ranging light toward the object to be measured, an optical member may be used to deflect the ranging light. In this case, in order to accurately deflect the ranging light, it is necessary to control the motor that drives the optical member so that the optical member is accurately synchronized.

Japanese Unexamined Patent Publication No. 2014-85134 Japanese Unexamined Patent Publication No. 2008-268004

The present invention provides a measuring device and a motor control method capable of accurately synchronously controlling an optical member.

The present invention is provided in a distance measuring unit that emits distance measuring light and receives reflected distance measuring light to perform distance measuring, and a common optical path of the distance measuring light and the reflected distance measuring light, and is provided in the common optical path of the distance measuring light and the reflected distance measuring light. It is provided with an optical axis deflection unit that deflects the optical axis of light in the same deviation angle and the same direction, an emission direction detection unit that detects the deviation angle and deflection direction by the optical axis deflection unit, and an arithmetic control unit. The optical axis deflector has a pair of overlapping disc-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 coincides with the detection rotation angle detected by the encoder and the target rotation angle. The present invention relates to a measuring device configured to detect the above-mentioned torque value for each motor and correct the torque value based on the detection time difference.

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, with respect to the motor in which the coincidence between the detected rotation angle and the target rotation angle is detected first. The present invention relates to a measuring device that corrects the torque value so as to weaken it.

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 said motor with respect to the motor in which a coincidence between the detected rotation angle and the target rotation angle is later detected. It relates to a measuring device that corrects to strengthen the torque value.

Further, in the present invention, the calculation control unit calculates an overrun amount of the motor from the rotation angle at the time of reversal detected when the motor is reversed and a preset reference target rotation angle, and uses the overrun amount as the overrun amount. Based on this, the present invention relates to a measuring device that corrects the target rotation angle so as to reduce the rotation angle at the time of reversal.

Further, in the present invention, the measuring device main body for accommodating the ranging unit, the optical axis deflecting unit, the injection direction detecting unit, and the arithmetic control unit, and the measuring device main body are rotated in the vertical direction and the horizontal direction. The present invention relates to a measuring device including a support portion that can support the measuring device, a rotation driving unit that rotates the measuring device main body in the vertical and horizontal directions, and an angle detector that detects the vertical and horizontal angles of the measuring device main body. It is a thing.

Further, in the present invention, the optical prism is formed in a central portion and has a ranging optical axis deflecting portion that deflects the ranging light in a required deflection angle and a required direction, and a ranging optical axis formed in the outer peripheral portion. The present invention relates to a measuring device having a reflection distance measuring optical axis deflection unit that deflects the reflected distance measuring light in the same direction and the same deviation angle as the deflection unit.

Further, the present invention relates to a measuring device in which the optical prism is a Fresnel prism.

Furthermore, the present invention is a motor control method for controlling the reversal of a motor, in which the time difference when the rotation angles of the pair of motors match the target rotation angles is calculated, and the motor is set based on the time difference. It relates to a motor control method for correcting a torque value for driving.

According to the present invention, a distance measuring unit that emits distance measuring light and receives reflected distance measuring light to perform distance measuring is provided in a common optical path of the distance measuring light and the reflected distance measuring light, and the distance measuring light and reflection are provided. It is provided with an optical axis deflection unit that deflects the optical axis of the ranging light in the same deviation angle and the same direction, an emission direction detection unit that detects the deviation angle and deflection direction by the optical axis deflection unit, and an arithmetic control unit. The optical axis deflector has a pair of overlapping disc-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 also has a detection rotation angle detected by the encoder and the target rotation angle. Since the matching is detected for each motor and the torque value is corrected based on the detection time difference, accurate synchronous rotation of the optical prism is possible, and the deflection direction set by the distance measuring light and the actual deflection direction are enabled. The deflection directions can be matched, accurate measurement results can be obtained, and the synchronous rotation can be performed accurately without considering individual differences of the motors, so that workability can be improved.

Further, according to the present invention, it is a motor control method for controlling the reversal of a motor, and the time difference when the rotation angles of the pair of motors match the target rotation angles is calculated, 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 excellent effect of improving workability is exhibited. ..

It is a front view which shows the measuring apparatus which concerns on embodiment of this invention. It is the schematic which shows the optical system of the measuring apparatus. It is an enlarged view of the optical axis deflection part of the optical system. (A) to (C) are explanatory views which show the action of the optical axis deflection part. It is a control figure explaining the control method of the motor at the time of synchronous rotation of an optical prism. (A) and (B) are explanatory views explaining the overrun which occurs when the motor is rotated. It is a control figure explaining the control method of synchronously rotating a motor at the time of synchronously rotating an optical prism. It is a control figure explaining the control method which prevents overrun of a motor at the time of synchronous rotation of an optical prism.

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

First, the measuring apparatus according to the embodiment of the present invention will be described with reference to FIGS. 1 and 2.

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

The rack portion 3 has a concave shape having a recess, and the measuring device main body 2 is housed in the recess. The measuring device main body 2 is supported by the suspension portion 3 via the vertical rotation shaft 6, and is rotatable in the vertical direction around the vertical rotation shaft 6.

A vertical driven gear 7 is fitted at the end of the vertical rotating 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 main body 2 is rotated in the vertical direction by the vertical drive motor 9.

Further, between the vertical rotation shaft 6 and the measuring device main body 2, a vertical rotation angle detector 11 (for example, an encoder) that detects a vertical angle (an angle in the rotation direction about the vertical rotation shaft 6) is detected. Is provided. The vertical rotation angle detector 11 detects the vertical rotation angle of the measuring device main body 2 with respect to the suspension portion 3.

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

The left and right driven gears 13 are fixed to the pedestal portion 4 concentrically with the left and right rotating shaft 12. A left-right drive motor 14 is provided on the suspension portion 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 suspension portion 3 is rotated in the left-right direction by the left-right drive motor 14.

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

Further, the pedestal portion 4 is provided on the surveying base 5, and the surveying base 5 is installed on a tripod (not shown). The surveying board 5 has an automatic leveling mechanism, and functions as a leveling unit for automatically leveling the measuring device main body 2.

By the cooperation of the vertical drive motor 9 and the left and right drive motor 14, the measuring device main body 2 can be directed in a desired direction. The support portion of the measuring device main body 2 is formed by the suspension portion 3 and the pedestal portion 4. Further, the vertical drive motor 9 and the left / right drive motor 14 form a rotary drive unit of the measuring device main body 2.

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

The ranging 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. Further, 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 reflector 36 as a deflection optical member provided on the light receiving optical axis 35 (described later) are used. The emission optical axis 31 is deflected so as to match the light receiving optical axis 35. The first reflecting mirror 34 and the second reflecting mirror 36 form an emission optical axis deflection portion.

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

The light receiving unit 18 has the light receiving optical axis 35, and the light receiving unit 18 is incident with reflected distance measuring light from a target having retroreflective properties such as an object to be measured, a prism, and a reflecting mirror.

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 arranged. The imaging lens 38 forms an image of the reflected distance measuring light on the light receiving element 37. The light receiving element 37 receives the reflected ranging light and emits a light receiving signal. The received light signal is input to the ranging unit 19.

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

The optical axis deflection unit 39 is composed of a pair of optical prisms 41a and 41b. The optical prisms 41a and 41b are disk-shaped, respectively, and are arranged on the light receiving optical axis 35 orthogonally to the light receiving optical axis 35, and the optical prisms 41a and 41b are overlapped and arranged in parallel. It is preferable that Fresnel prisms are 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 the ranging optical axis deflecting portion 39a which is the first optical axis deflecting portion through which the distance measuring light is transmitted, and the portion other than the central portion is transmitted by the reflected distance measuring light. It is a reflection distance measurement optical axis deflection unit 39b which is a second optical axis deflection unit.

The Fresnel prism used as the optical prisms 41a and 41b is composed of prism elements 42a and 42b formed in parallel and a large number of prism elements 43a and 43b, respectively, 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 form the distance measuring optical axis deflection unit 39a, and the prism elements 43a and 43b form the reflection distance measurement optical axis deflection unit 39b.

The Fresnel prism may be manufactured from optical glass, or 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 individually rotatably arranged around the light receiving optical axis 35, respectively. By independently controlling the rotation direction, the amount of rotation, and the rotation speed of the optical prisms 41a and 41b, the emitted optical axis 31 of the distance measurement light to be emitted is deflected in an arbitrary direction, and the reflected reflection is received. The light receiving optical axis 35 of the ranging light is deflected so as to be parallel to the emitted optical axis 31.

The outer shapes of the optical prisms 41a and 41b are circular shapes centered on the light receiving optical axis 35, respectively, and the optical prisms 41a and 41b can obtain a sufficient amount of light in consideration of the spread of the reflected distance measuring light. The diameter is set.

A ring gear 44a is fitted on the outer circumference of the optical prism 41a, and a ring gear 44b is fitted on the outer circumference 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, the 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 46a and 46b are electrically connected to the motor driver 23.

As the motors 46a and 46b, those capable of detecting the rotation angle or those that rotate according to the drive input value, for example, a pulse motor are used. Alternatively, the rotation amount of the motor may be detected by using a rotation angle detector such as an encoder that detects the rotation amount (rotation angle) of the motor. The amount of rotation of the motors 46a and 46b is 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 deflection unit 39a, etc. constitute a light projection optical system, and the reflection distance measuring optical axis deflection unit 39b, the imaging lens 38, etc. constitute a light receiving optical system. ..

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

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

The imaging unit 21 is, for example, a camera having an angle of view of 50 °, and acquires image data including an object to be measured. The imaging unit 21 has an imaging optical axis 47 in which the measuring device main body 2 extends in the 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. There is. Further, the distance between the imaging optical axis 47 and the emitting optical axis 31 is also a known value.

The image sensor 48 of the image sensor 21 is a CCD or CMOS sensor that is an aggregate of pixels, and each pixel can specify the position on the image element. 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 detection unit 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 the signals from the encoders 58a and 58b (described later). Further, the injection direction detection unit 22 calculates the rotation position of the optical prisms 41a and 41b based on the rotation angles of the motors 46a and 46b. Further, the emission direction detection unit 22 calculates the deviation angle and the emission direction of the ranging light based on the refractive index and the rotation 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 on each of the optical prisms 41a and 41b, and the rotation position of the optical prisms 41a and 41b may be calculated based on the detection result of the encoder.

Further, the tracking light emitting unit 24 has a tracking light axis 49, and a light emitting element 51, for example, a laser diode (LD) that emits tracking light having a wavelength different from that of distance measuring light is provided on the tracking light axis 49. ing. Further, a projection 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 matches 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 that it matches the light receiving optical axis 35 (that is, the emitting optical axis 31).

Further, the tracking light receiving unit 25 includes a third reflecting mirror 53 which is a deflection optical member and has a wavelength selection function, a condenser lens 54, a fourth reflecting mirror 55 which is a deflection 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 distance measuring light having a different wavelength. Further, 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, and the fourth reflecting mirror 55 and the tracking light receiving element 56 are It is provided on the tracking light receiving optical axis 57. Further, the condenser lens 54 is arranged between the third reflecting mirror 53 and the fourth reflecting mirror 55.

When detecting and tracking a target, a reflector having retroreflective properties, for example, a prism is used as a measurement object. The reflected tracking light reflected by the prism (not shown) passes through the optical axis deflection unit 39, is reflected by the third reflector 53, is condensed by the condenser lens 54, and is condensed by the condenser lens 54. It is deflected on the tracking light receiving light axis 57 by 55, and is received by the tracking light receiving element 56. The tracking light receiving element 56 is a CCD or CMOS sensor which is an aggregate of pixels, and each pixel can specify the position on the image element. The tracking light receiving element 56 receives the reflected tracking light and emits a light receiving 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 the light received from the reflected tracking light on the tracking light receiving element 56, and calculates the 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 arithmetic control unit 27 is composed of an input / output control unit, an arithmetic unit (CPU), a storage unit, and the like. The storage unit has a range-finding program for controlling the range-finding operation, a detection program for detecting a target described later, a tracking program for controlling the tracking operation, and a motor driver 23 for controlling the drive of the motors 46a and 46b. Prism control program, main body control program for controlling the drive of the vertical drive motor 9 and the left and right drive motor 14, calculation result of the emission direction of the ranging light from the emission direction detection unit 22, and the vertical rotation angle detection. A direction angle calculation program that calculates the direction angle (horizontal angle, vertical right angle) of the ranging light based on the detection results of the device 11 and the left / right rotation angle detector 16, and displays image data, ranging data, etc. on the display unit 29. A program such as an image display program for making the data is stored. Further, the storage unit stores distance measurement data, image data, rotation 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 measuring device 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 can be obtained. The minimum deviation angle is the position where one of the optical prisms 41a and 41b is rotated by 180 °, the deviation angle is 0 °, and the optical axis of the emitted laser beam (distance measuring light) is the emission. It is parallel to the optical axis 31. The prism elements 42a and 42b can scan a measurement target object or a measurement target area with distance measuring light in a range of, for example, ± 20 °.

Distance measuring light is emitted from the light emitting element 32, and the distance measuring light is converted into a parallel luminous flux by the light projecting lens 33, and is passed through the distance measuring optical axis deflection portion 39a (the prism elements 42a, 42b) to be measured. Alternatively, it is ejected toward the measurement target area. Here, by passing through the distance measuring optical axis deflection 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 in the object to be measured or the measurement target area is incident through the reflected distance measuring optical axis deflection portion 39b (the prism elements 43a, 43b), and is received by the imaging lens 38. It is focused on the element 37.

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

Further, by combining the rotational positions of the optical prism 41a and the optical prism 41b, the emitted ranging light can be deflected in an arbitrary deflection direction and declination angle.

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

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

Needless to say, the reflection distance measurement optical axis deflection unit 39b is integrally rotated with the distance measurement optical axis deflection 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 The combined deflection C is obtained as the angle difference θ between the optical prisms 41a and 41b.

Therefore, if the optical axis deflection unit 39 is rotated once each time the angle difference θ is changed and the light is irradiated for each rotation, the distance measuring light can be scanned linearly. Further, each time 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 a state of being irradiated. Further, if the optical prism 41a and the optical prism 41b are rotated in 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 rotation speed slower than the rotation speed of the optical prism 41a, the distance measuring light rotates while the angle difference θ gradually increases. Therefore, the scanning locus of the ranging light has a spiral shape.

Furthermore, by individually controlling the rotation direction and rotation speed of the optical prism 41a and the optical prism 41b, the scanning locus of the ranging light can be measured in the radial direction (radial scanning) centered on the emission optical axis 31. Various scanning states can be obtained, such as horizontal and vertical directions.

As a measurement mode, the distance can be measured at a specific measurement point by fixing the optical axis deflection unit 39 for each required declination and performing the distance measurement. Further, by performing distance measurement while changing the declination angle of the optical axis deflection unit 39, that is, by performing distance measurement while scanning the distance measurement light, distance measurement data about the measurement point on the scanning locus is obtained. Can be obtained.

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

Further, as described above, the measuring device 1 includes the imaging unit 21, and the 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 of 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 is almost the same as the range. Therefore, the measurer can easily visually identify the measurement range, and can search for the measurement object or select the measurement object from the image displayed on the display unit 29, so that the measurement object is viewed. There is no need to follow.

The angle of view of the imaging unit 21 and the deflection range of 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 perfect. It may be made to match.

When the object to be measured is selected, the optical prisms 41a and 41b are rotated so that the distance measuring light is deflected toward the object to be measured. When the object to be measured is outside the imaging range of the imaging unit 21, the vertical drive motor 9 and the left / right drive motor 14 are moved so that the object to be measured 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 to each other and both optical axes have a known relationship, the arithmetic control unit 27 has the image center and the injection 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 ranging 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.

Further, the measuring device 1 includes the tracking portion 26. Tracking light is emitted from the light emitting element 51, and the tracking light is converted into a parallel light beam by the projection lens 52, and is passed through the distance measuring optical axis deflection portion 39a (the prism elements 42a, 42b) to be measured, for example. It is ejected toward a retroreflective target such as a prism or a reflector. Here, by passing through the distance measuring optical axis deflecting portion 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 deflection portion 39b (the prism elements 43a and 43b), and is incident on the imaging lens 38, the third reflecting mirror 53, and the focusing. The light is focused 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 the light received from the reflected tracking light on the tracking light receiving element 56, and calculates the 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 the drive of the motors 46a and 46b based on the calculation result of the tracking unit 26. The arithmetic control unit 27 rotates the optical prisms 41a and 41b 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 device main body 2 makes the tracking light follow the movement of the target in a stationary state, and tracks the target.

Needless to say, when the tracking range by the optical axis deflection unit 39 is exceeded, the vertical drive motor 9 and the left / right drive motor 14 are driven and the measuring device main body 2 is rotated so as to face the target. Absent.

Hereinafter, in the case of intensively measuring a limited portion of the object to be measured, the optical prism 41a and the optical prism 41b are reciprocally rotated at high speed, and the portion is reciprocally scanned by distance measuring light. Inversion control of the motors 46a and 46b will be described.

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

When a signal a indicating a rotation direction, for example, forward rotation and a signal b having a preset torque value are input to the motor driver 23a from the arithmetic control unit 27, the motor driver 23a is input. The motor 46a is rotated based on the signal a and the signal b.

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 preset target rotation angle at the time of forward rotation is input to the determination unit 59a as a signal d from the calculation control unit 27. The determination unit 59a determines whether or not the detected rotation angle from the encoder 58a and the target rotation angle from the arithmetic control unit 27 match, and when the detected rotation angle and the target rotation angle match, the determination unit 59a determines. 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 which is a rotation instruction (reversal instruction) in the direction opposite to the previous time and a signal b which is a torque value at the time of reverse rotation. Output to the motor driver 23a.

The above process is repeatedly executed until the measurement of the object to be measured is completed and the reversal control of the motor 46a is completed. Further, by performing the above processing, the reciprocating operation at the upper limit of the response speed of the motors 46a and 46b becomes possible. Further, by repeating the above processing, high-speed scanning over a narrow scanning range becomes possible.

Since the reversing control for the motor 46b is the same as the reversing control for the motor 46a, the description thereof will be omitted.

Further, in FIG. 5, the determination units 59a and 59b are described as independent configurations, but the determination units 59a and 59b are actually a part of the calculation control unit 27.

FIG. 6A shows a part of the rotation range 61a of the motor 46a, and the rotation loci of the reversing target positions 62a and 62b and the reversing target positions 62a and 62b when the motor 46a is reciprocated. 63a and 63b are shown. Further, FIG. 6B shows a part of the rotation range 61b of the motor 46b, and the rotation up to the reversal target positions 64a and 64b and the reversal target positions 64a and 64b when the motor 46b is reciprocated. The loci of 65a and 65b are shown. Since the same control as that of the motor 46a is performed on the motor 46b, FIG. 6A will be described below.

As shown in FIG. 6A, when the rotation of the motor 46a is stopped at the reversal target position 62a, an overrun 66a occurs, and when the rotation of the motor 46a is stopped at the reversal target position 62b, Overrun 66b occurs. Therefore, the position where the rotation of the motor 46a is actually reversed is a position that is rotated by the overrun 66a, 66b from the reverse target positions 62a, 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 change depending on the weight of the motor 46a, the rotational moment, the spread of grease in the bearing portion, and the like. Further, the rotation speed of the motor 46a also changes depending on the weight of the motor 46a, the spread of grease in the bearing portion, and the like. Therefore, the change is not uniform due to individual differences due to manufacturing errors. Further, even while the motor 46a is being driven, changes occur due to changes in the environment such as temperature changes and humidity changes. Therefore, it is difficult to grasp and control the rotation speeds of the overruns 66a and 66b and the motor 46a.

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

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

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

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

When the arithmetic control unit 27 inputs a signal a indicating the rotation direction and a signal b which 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 or not the detected rotation angle from the encoder 58a and the target rotation angle (signal d) from the arithmetic control unit 27 match, and the detected rotation angle and the target rotation angle match. At that time, the rotation completion signal e is output to the arithmetic control unit 27.

Similarly, when the calculation control unit 27 inputs a rotation direction instruction (signal a) and a preset torque value (signal b) 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 and the target rotation angle (signal d) from the arithmetic control unit 27 match, and the detected rotation angle and the target rotation angle match. At that time, the rotation completion signal e is output to the arithmetic control unit 27.

The arithmetic control unit 27 receives the rotation completion signal e from one of the rotation completion signal e from the determination unit 59a and the rotation completion signal e from the determination unit 59b, and then 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. .. Regarding the torque correction value, a data table of the time difference of the rotation completion signal e between the motors 46a and 46b and the torque correction value is created in advance, and the torque correction value is calculated from the data table. May be good. Alternatively, the time difference after the 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 receives the torque correction value from the signal a which is an instruction (reversal instruction) in the rotation direction opposite to the previous time and the preset torque value (signal b). The torque value obtained by subtracting (signal f), that is, the torque value obtained by adding a negative torque correction value to the preset torque value is output to the motor driver 23a.

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

Further, a signal a which is an instruction (reversal instruction) in the rotation direction opposite to the previous time and a torque value (signal b) similar to the previous time are input to the motor driver 23b, and the motor 46b is sent to the previous time. In the opposite direction, rotate with the same driving force as last time.

The above process is repeatedly executed until the measurement of the object to be measured is completed and the inversion control of the motors 46a and 46b is completed.

The torque value is controlled to be weakened based on the time difference with respect to the motor 46a to which the rotation completion signal e is input first, that is, with respect to the motor 46a having a rotation speed faster than that of the motor 46b. 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 signal e of the motor 46a and the motor 46b can be detected simultaneously or substantially simultaneously. Can be done.

Therefore, inversion control in which the motors 46a and 46b are rotated in an accurate synchronous manner is possible, and accurate synchronous rotation of the optical prisms 41a and 41b is possible. Therefore, the scanning shape of the set ranging light and the actual ranging are measured. The scanning shape of the light can be matched, and an accurate measurement result of the object to be measured can be obtained.

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

Therefore, even when motors having individual differences such as manufacturing error and grease spread are used as the motors 46a and 46b, they can be rotated accurately in synchronization. Therefore, even if there are individual differences or assembly errors of the motors 46a and 46b, synchronous control is performed based on the actual rotation state, so that it is not necessary to consider individual differences and the like, and 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, but the rotation completion signal e is input to the motor 46b later. On the other hand, a negative torque correction value (signal f) may be subtracted from a preset torque value (signal b) based on the time difference, and the torque value may be controlled to be strengthened.

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

Further, in the above, the torque value is corrected at each inversion timing of the motors 46a and 46b, but the torque value may be corrected every time the motors 46a and 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. Since the reversal control performed on the motor 46b is the same as that of the motor 46a, the case where the reversal control of the motor 46a is performed will be described below.

When the inversion control is started, 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 target rotation angle (signal d) at the time of forward rotation from the arithmetic control unit 27 set in advance and the detection rotation angle match, and the detected rotation angle and the target rotation angle are combined with each other. At the same time, 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 (reversal instruction) (signal a) in the direction opposite to the previous time 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 calculation control unit 27 to the determination unit 68a. The motor driver 23a emits a drive signal g for rotating the motor 46a in the opposite direction based on the input rotation instruction (reversal instruction) and torque value.

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

The determination unit 68a uses the detected rotation angle (signal h) when the increase of the detected rotation angle (signal c) from the encoder 58a is stopped or starts to decrease as the rotation angle at the time of reversal, and at the time of the 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 overrun amount.

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

The reference target rotation angle is a reference value for detecting the overrun of the motor 46a, and is always constant. When the control of the motor 46a is started, the target rotation angle and the reference target rotation angle coincide with each other.

Based on the input overrun amount, the calculation control unit 27 corrects the target rotation angle so as to reduce the rotation angle at the time of inversion by the amount of overrun, and calculates a new target rotation angle at the time of forward rotation. Further, 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 a rotation direction to the determination unit 68a. The calculated new target rotation angle at the time of forward rotation is a value different from the reference target rotation angle.

Further, when the calculation control unit 27 outputs a forward reversal instruction and the increase in the detected rotation angle stops or starts to decrease, the rotation angle of the motor 46a actually reverses in the forward direction. It is detected by the encoder 58a as the rotation angle at the time of reversal, which is the angle at the time of rotation, and is 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. It is output to the arithmetic control unit 27 together with the rotation completion signal e of. The target rotation angle at this time and the reference target rotation angle are the same.

Based on the input overrun amount, the calculation control unit 27 corrects the target rotation angle so as to reduce the rotation angle at the time of inversion by the amount of overrun, and calculates a new target rotation angle at the time of reverse rotation. Further, the arithmetic control unit 27 outputs a rotation instruction and a torque value in the opposite direction to the previous time to the motor driver 23a, and outputs a rotation direction to the determination unit 68a. 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 at the time of inversion and the reference target rotation angle, and signals the completion of rotation. e and the overrun amount are output to the arithmetic control unit 27.

The above process is repeatedly executed until the measurement of the object to be measured 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 rotation angle at the time of inversion at the time of inversion instruction, that is, the overrun amount is calculated, and the rotation angle at the time of inversion is calculated by the overrun amount. The target rotation angle is modified so as to reduce the number of rotations, and the rotation angle at the time of reversal is controlled to be close to the reference target rotation angle.

Therefore, since the overrun when the motors 46a and 46b are driven can be suppressed, the reciprocating length of the set distance measuring light and the reciprocating length of the actual distance measuring light can be matched or substantially matched. , Accurate measurement results of the object to be measured can be obtained.

Further, since the correction of the target rotation angle is executed at each inversion timing of the motors 46a and 46b, 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 that have individual differences such as manufacturing errors and the spread of grease in the bearings, or for motors that change during driving due to changes in the environment, etc., the same processing is performed and overrun. Therefore, it is not necessary to consider individual differences of the motor, and workability can be improved.

Although the determination units 68a and 68b are described as independent configurations in FIG. 8, the determination units 68a and 68b are actually a part of the calculation control unit 27.

Further, in FIG. 7, the torque value is a variable value and the rotation angle is a fixed value to perform synchronous rotation of the motors 46a and 46b. In FIG. 8, the torque value is a fixed value and the rotation angle is a variable value and the motor 46a is rotated. Although the overrun of, 46b is suppressed, both the torque value and the rotation angle may be variable values.

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

Further, in the present embodiment, the case where the control for synchronously rotating the motors 46a and 46b and the control for suppressing the overrun are applied to the measuring device 1 has been described. For example, a processing machine for processing a workpiece with a laser beam has been described. The control of this embodiment can be applied to other devices as long as it is a device that requires accurate synchronous rotation of two motors and suppression of overrun, such as control of the direction of a laser beam. Needless to say. Further, the control of this embodiment can be applied to a hollow brushless motor (direct drive motor), an ultrasonic motor, and the like.

1 Measuring device 2 Measuring device 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 unit

Claims (7)

It is provided in the common optical path of the ranging light and the reflected ranging light, and the distance measuring unit that emits the ranging light and receives the reflected ranging light to perform the ranging, and the optical axis of the ranging light and the reflected ranging light. The optical axis deflection unit includes an optical axis deflection unit that deflects the same deflection angle and the same direction, an emission direction detection unit that detects the deviation angle and deflection direction by the optical axis deflection unit, and an arithmetic control unit. Each unit has a pair of overlapping disc-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 motor is controlled based on a preset torque value and a target rotation angle so that the optical prism reciprocates, and the detection rotation angle detected by the encoder matches the target rotation angle for each motor. A measuring device configured to detect and correct the torque value based on the detection time difference. 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 is detected first. The measuring device according to claim 1, which is modified. The calculation control unit calculates a torque correction value based on the time difference, and based on the torque correction value, strengthens the torque value for the motor whose coincidence between the detected rotation angle and the target rotation angle is later detected. The measuring device according to claim 1 to be modified. The calculation control unit calculates an overrun amount of the motor from the rotation angle at the time of 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 device according to any one of claims 1 to 3, wherein the target rotation angle is corrected so as to reduce the angle. A measuring device main body that houses the distance measuring unit, the optical axis deflection unit, the ejection direction detecting unit, and the arithmetic control unit, and a support that rotatably supports the measuring device main body in the vertical and horizontal directions. Of claims 1 to 4, which includes a unit, a rotation drive unit that rotates the measuring device main body in the vertical and horizontal directions, and an angle detector that detects the vertical and horizontal angles of the measuring device main body. The measuring device according to any one item. The optical prism is formed in a central portion and has a ranging optical axis deflecting portion that deflects the ranging light in a required deflection angle and a required direction, and is formed in an outer peripheral portion and is the same as the ranging optical axis deflecting portion. The measuring device according to any one of claims 1 to 5, further comprising a reflected distance-finding optical axis deflecting portion that deflects the reflected distance-finding light in the same direction. The measuring device according to any one of claims 1 to 6, wherein the optical prism is a Fresnel prism.

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