Calibration method of attitude probe

Abstract

The present disclosure describes a method for calibrating a posture probe, wherein the posture probe includes a reference layer provided with a position-sensitive detector, a prism layer provided with hollow corner cube prisms, and an intermediate layer provided between the reference layer and the prism layer, wherein the intermediate layer includes a pinhole plate provided with a through hole. The calibration method includes: disposing the posture probe on a rotating platform having a rotation axis, wherein the rotating platform is configured to rotate relative to a base with the rotation axis as the rotation center, adjusting the through hole of the transmitting module and the posture probe to the axis of the rotation axis, the posture probe receiving a light beam generated by the transmitting module, rotating the rotating platform and driving the posture probe to rotate, and using the position-sensitive detector to record the trajectory of the light beam and calibrate the coordinate origin of the coordinate system based on the trajectory. Thus, the specific position of the coordinate origin of the coordinate system on the position-sensitive detector can be obtained through the trajectory of the light beam on the position-sensitive detector, thereby achieving calibration of the coordinate origin of the coordinate system.

Description

Technical Field

[0001] The present invention generally relates to the intelligent manufacturing equipment industry, and in particular to a calibration method for a posture probe. Background Art

[0002] With the continuous innovation of industrial technology, the use of laser trackers to measure the position and posture of targets has become an important method in the intelligent manufacturing equipment industry. Generally speaking, lasers have multiple advantages such as high brightness, good monochromaticity, high coherence, and strong directionality. These advantages enable laser trackers to achieve excellent measurement results when used in them.

[0003] As a precision mechanical instrument, the laser tracker needs to be used in conjunction with a posture probe (target ball). The posture probe is used to reflect the laser back to the laser tracker, so that the position of the posture probe can be calculated.

[0004] In existing technologies, improving the detection accuracy of laser trackers typically requires increasing the vertical orthogonality of the laser tracker's horizontal, pitch, and optical axes, or calibrating the laser tracker. However, excessive focus on the laser tracker can easily overlook the impact of the attitude probe on detection accuracy. In reality, the machining accuracy of the attitude probe also significantly affects the detection accuracy of the laser tracker. Therefore, calibrating the attitude probe is also an effective means of improving the detection accuracy of laser trackers. Summary of the Invention

[0005] The present disclosure is proposed in view of the above-mentioned state of the prior art, and its purpose is to provide a calibration method for an attitude probe that can calibrate the attitude probe and thus improve detection accuracy.

[0006] To this end, the present disclosure provides a calibration method for a posture probe, wherein the posture probe includes a reference layer provided with a position-sensitive detector, a prism layer provided with a hollow corner cube prism, and an intermediate layer provided between the reference layer and the prism layer, wherein the intermediate layer includes a pinhole plate provided with a through hole, and when the posture probe receives a light beam, the light beam passes through the hollow corner cube prism and the through hole to reach the position-sensitive detector. The calibration method is a calibration method for calibrating the coordinate system of the posture probe, characterized in that it includes: setting the posture probe on a rotating platform having a rotation axis, the rotating platform is configured to rotate relative to a base with the rotation axis as the rotation center, adjusting the transmitting module and the through hole of the posture probe to the axis of the rotation axis, the posture probe receiving the light beam generated by the transmitting module, rotating the rotating platform and driving the posture probe to rotate, using the position-sensitive detector to record the trajectory of the light beam and calibrating the coordinate origin of the coordinate system based on the trajectory.

[0007] In this case, if the reference layer and the prism layer (middle layer) are not parallel, when the attitude probe rotates on the rotating platform, the light beam will move in the position-sensitive detector. At the same time, the specific position of the coordinate origin of the coordinate system in the position-sensitive detector can be obtained through the trajectory of the light beam in the position-sensitive detector, thereby realizing the calibration of the coordinate origin of the coordinate system. The calibration results can then be used in subsequent detection tasks to correct the actual measurement values, thereby improving the measurement accuracy of the laser tracker.

[0008] In addition, in the calibration method involved in the present disclosure, optionally, when the transmitting module and the through hole are adjusted to the axis of the rotation shaft, a fixing frame provided on the base is used to set the shooting module to a first position, the first position being located on the axis of the rotation shaft, the lens of the shooting module is aligned with the through hole, the rotating platform is rotated and the attitude probe is driven to rotate and the shooting is performed using the shooting module, and based on the position of the through hole, it is determined whether the through hole is located on the axis of the rotation shaft. In this case, since the shooting module is located on the straight line where the rotation shaft is located, it is possible to determine whether the through hole is located on the axis of the rotation shaft.

[0009] In addition, in the calibration method of the present disclosure, optionally, when the attitude probe rotates, if the position of the through hole changes, it is determined that the attitude probe is not located on the axis of the rotation shaft, and the position of the attitude probe is readjusted. If the position of the through hole does not change, it is determined that the attitude probe is located on the axis of the rotation shaft. In this case, whether the through hole of the attitude probe is located on the axis of the rotation shaft can be determined by the change in the position of the through hole.

[0010] In addition, in the calibration method of the present disclosure, optionally, after the attitude probe is set on the axis of the rotation shaft, the camera module is removed and the transmitter module is set to the first position. In this case, the transmitter module can be located on the axis of the rotation shaft.

[0011] In addition, in the calibration method involved in the present disclosure, optionally, it also includes calibrating the direction of the coordinate axis of the coordinate system, which includes: placing the attitude adjustment platform on the rotating platform, placing the attitude probe on the attitude adjustment platform, adjusting the attitude of the attitude adjustment platform so that the central axis of the hollow corner cube prism is parallel to the rotating platform, setting the transmitting module at a second position of the fixed frame, the second position is located on the central axis of the hollow corner cube prism, the attitude probe receives the light beam generated by the transmitting module, records the position where the light beam is incident on the position sensitive detector as a first target position, rotates the rotating platform to rotate the attitude probe by a preset angle, records the position where the light beam is incident on the position sensitive detector as a second target position, and calibrates the direction of the coordinate axis of the coordinate system based on the first target position and the second target position. In this case, the direction of the coordinate axis of the sensor coordinate system can be calibrated, and then the direction of the coordinate axis of the target coordinate system can be calibrated.

[0012] Additionally, in the calibration method of the present disclosure, optionally, the direction of the line connecting the first target position and the second target position is defined as the direction of the first coordinate axis of the coordinate system, and in the position-sensitive detector, the direction perpendicular to the line connecting the first target position and the second target position is defined as the direction of the second coordinate axis. In this case, the directions of the coordinate axes of the sensor coordinate system can be calibrated, and thus the directions of the target coordinate axes can be calibrated.

[0013] In addition, in the calibration method disclosed herein, optionally, after the attitude probe is rotated by a preset angle, the attitude of the attitude adjustment platform is adjusted so that the central axis of the hollow corner cube is parallel to the rotating platform. In this case, the attitude probe is ensured to be horizontal when the first target position and the second target position are obtained, thereby improving calibration accuracy.

[0014] In addition, in the calibration method of the present disclosure, optionally, the preset angle is less than 90°. In this case, the light beam can be on the position sensitive detector during the rotation of the posture probe.

[0015] In addition, the calibration method of the present disclosure optionally further includes calibrating the distance between the position sensitive detector and the through hole, which includes: using a laser tracker to emit a laser toward the through hole of the attitude probe, causing the attitude probe to move a preset distance along the second coordinate axis, using the laser tracker to record the horizontal angle of the attitude probe during movement, obtaining the distance the light beam moves in the position sensitive detector, and calibrating the distance between the position sensitive detector and the through hole based on the movement distance and the horizontal angle. In this case, the distance between the position sensitive detector and the through hole can be calibrated.

[0016] In addition, in the calibration method involved in the present disclosure, optionally, the distance between the position sensitive detector and the through hole satisfies the formula: Wherein, d represents the distance between the coordinate origin and the through hole, L represents the moving distance, and α represents the horizontal angle. In this case, the distance between the position sensitive detector and the through hole can be obtained, and then the distance between the position sensitive detector and the through hole can be calibrated.

[0017] According to the calibration method disclosed in the present invention, the attitude probe can be calibrated, thereby improving the detection accuracy of the attitude probe. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present disclosure will now be explained in further detail, by way of example only, with reference to the accompanying drawings, in which:

[0019] Figure 1 Schematic diagram showing an application scenario of the attitude probe involved in the embodiment of the present disclosure.

[0020] Figure 2 2 is a schematic diagram showing a posture probe according to an embodiment of the present disclosure.

[0021] Figure 3 Schematic diagram showing a coordinate system in an ideal case according to an embodiment of the present disclosure.

[0022] Figure 4 Schematic diagram showing a coordinate system in an actual situation involved in an embodiment of the present disclosure.

[0023] Figure 5 1 is a flow chart showing a calibration method according to an embodiment of the present disclosure.

[0024] Figure 6 It is a schematic diagram showing the process of calibrating the coordinate origin of the coordinate system in the calibration method involved in the embodiment of the present disclosure.

[0025] Figure 7 It is a schematic diagram showing a scenario in which the transmitting module and the through hole are adjusted to the axis in the calibration method involved in the embodiment of the present disclosure.

[0026] Figure 8 3 is a schematic diagram showing a scene of calibrating the coordinate origin of a coordinate system in a calibration method according to an embodiment of the present disclosure.

[0027] Figure 9 3 is a schematic diagram showing a flow chart of calibrating the directions of coordinate axes of a coordinate system in a calibration method according to an embodiment of the present disclosure.

[0028] Figure 10 It is a schematic diagram of a scene showing the directions of coordinate axes of a calibration coordinate system in a calibration method according to an embodiment of the present disclosure.

[0029] Figure 11 1 is a top view of a scene when measuring a first target position in a calibration method according to an embodiment of the present disclosure.

[0030] Figure 12 1 is a top view of a scene when measuring the second target position in the calibration method according to an embodiment of the present disclosure.

[0031] Figure 13 Schematic diagram showing a first target position and a second target position in a position sensitive detector in a calibration method according to an embodiment of the present disclosure.

[0032] Figure 14 1 is a schematic diagram showing a flow chart of calibrating the distance between the coordinate origin and the through hole in the calibration method according to an embodiment of the present disclosure.

[0033] Figure 15 3 is a schematic diagram showing the principle of calibrating the distance between the coordinate origin and the through hole in the calibration method involved in the embodiment of the present disclosure.

[0034] Reference numerals

[0035] 10. Tracker,

[0036] 20. Attitude probe,

[0037] 21. Prism layer, 22. Pinhole plate, 23. Reference layer,

[0038] 211. Hollow corner cube prism, 212. Gravity inclination sensor, 213. Indicator unit

[0039] 231. Position sensitive detector,

[0040] 31. Base, 32. Rotating platform, 33. Fixed frame, 34. Shooting module, 35. Transmitting module,

[0041] 36. Attitude adjustment platform, 361. Adjustment screw DETAILED DESCRIPTION

[0042] The preferred embodiments of the present disclosure are described in detail below with reference to the accompanying drawings. In the following description, identical components are assigned identical reference numerals, and duplicate descriptions are omitted. In addition, the accompanying drawings are merely schematic, and the proportions of the dimensions of the components and the shapes of the components may differ from the actual ones.

[0043] It should be noted that the terms "including" and "having" and any variations thereof in this disclosure, such as a process, method, system, product or device that includes or has a series of steps or units, are not necessarily limited to those steps or units clearly listed, but may include or have other steps or units that are not clearly listed or are inherent to these processes, methods, products or devices.

[0044] In addition, the subheadings and the like in the following description of this disclosure are not intended to limit the content or scope of this disclosure, but are merely provided as a guide for reading. Such subheadings should not be understood as dividing the content of the article, nor should the content under the subheading be limited to the scope of the subheading.

[0045] Figure 1 Schematic diagram showing an application scenario of the posture probe 20 involved in the embodiment of the present disclosure. Figure 2 2 is a schematic diagram showing the attitude probe 20 according to the embodiment of the present disclosure.

[0046] For some examples, see Figure 1 The attitude probe 20 involved in the present disclosure can cooperate with a laser detector to achieve ranging and tracking of the attitude probe 20. Distance measurement can refer to measuring the distance between the attitude probe 20 and the laser tracker 10. Specifically, the laser detector can emit a laser beam, and the attitude probe 20 can reflect the laser beam back to the laser detector after receiving the laser beam. The laser tracker 10 can calculate the distance between the attitude probe 20 and the laser detector based on the laser beam reflected from the attitude probe 20 and track the attitude probe 20.

[0047] In some examples, the gesture probe 20 may include a reference layer 23 having a position-sensitive detector (PSD) 231, a prism layer 21 having hollow corner cube prisms 211, and an intermediate layer disposed between the reference layer 23 and the prism layer 21. In some examples, the intermediate layer may include a pinhole plate 22 having a through hole. When the gesture probe 20 receives a light beam, the light beam passes through the hollow corner cube prisms 211 and the through hole to reach the position-sensitive detector 231. In some examples, the opening of the hollow corner cube prisms 211 may be located within the through hole of the pinhole plate 22, meaning that the geometric center of the opening of the hollow corner cube prisms 211 may coincide with the geometric center of the through hole. In this case, the hollow corner cube prisms 211 can reflect the laser beam back to the laser detector, and the position-sensitive detector 231 can receive the laser beam that has passed through the intermediate layer. Thus, the position-sensitive detector 231 can sense changes in the position and posture of the gesture probe 20, thereby enabling ranging and tracking of the gesture probe 20.

[0048] In some examples, the attitude probe 20 may include a gravity tilt sensor 212. In this case, the attitude of the attitude probe 20 can be obtained using the gravity tilt sensor 212. In some examples, the gravity tilt sensor 212 may be provided on the prism layer 21. In some examples, the gravity tilt sensor 212 may be provided on the side of the prism layer 21. Specifically, the prism layer 21 may be prism-shaped and include an incident surface, an exit surface, and four side surfaces. The four side surfaces may include a top side surface, a bottom side surface, a left side surface, and a right side surface. The gravity tilt sensor 212 may be provided on the top side surface, and when the attitude probe 20 is in a horizontal state, the reading of the gravity tilt sensor 212 is 0.

[0049] In some examples, the posture probe 20 may include a plurality of indication units 213. In this case, the posture of the posture probe 20 can be obtained according to the spatial position of the indication unit 213.

[0050] Figure 3 Schematic diagram showing a coordinate system in an ideal case according to an embodiment of the present disclosure. Figure 4 Schematic diagram showing a coordinate system in an actual situation involved in an embodiment of the present disclosure.

[0051] For some examples, see Figure 3 and Figure 4 , two coordinate systems can be defined in the attitude probe 20, including a three-dimensional target coordinate system {O T ,X T Y T Z T} and the two-dimensional sensor coordinate system {O D ,X D Y D}. Among them, O T is the origin of the target coordinate system, X T The axis is the first coordinate axis (X axis) of the target coordinate system, and the Y T The axis is the second coordinate axis (Y axis) of the target coordinate system, and the Z axis is the second coordinate axis (Y axis) of the target coordinate system. T Axis is the third coordinate axis (Z axis) of the target coordinate system, O D is the origin of the sensor coordinate system, X D The axis is the first coordinate axis (X axis) of the sensor coordinate system, and the Y D The axis is the second coordinate axis (Y axis) of the sensor coordinate system. In some examples, the target coordinate system may also be referred to as the through-hole coordinate system, and the sensor coordinate system may also be referred to as the PSD coordinate system.

[0052] In some examples, the coordinate system referred to in this disclosure may refer to a target coordinate system or a sensor coordinate system.

[0053] In some examples, the target coordinate system can be based on the geometric center of the target internal corner cube prism opening or the through hole of the pinhole plate 22 as the coordinate origin, and the vertical direction of the through hole to the surface of the position sensitive detector 231 is Z T The positive direction of the X axis. T Axis and X D The directions of the axes are the same, Y T Axis and Y D In some examples, the sensor coordinate system may be a two-dimensional coordinate system built into the position sensitive detector 231 .

[0054] For some examples, see Figure 3 In a rational situation, the prism layer 21, the reference layer 23 and the intermediate layer can be parallel to each other. T Axis and Y T The axis may be parallel to the prism layer 21 and the intermediate layer. In other words, the X axis of the target coordinate system T Axis and Y T The X axis can be perpendicular to the central axis of the hollow corner cube prism 211, that is, the central axis of the hollow corner cube prism 211 can be perpendicular to the X axis. T O T Y T In this case, the relative position relationship between the target coordinate system and the sensor coordinate system, the origin of the sensor coordinate system, X D Axis direction, Y D The direction of the axis (e.g., directly measured, directly obtained based on the processing drawing), so that the points in the sensor coordinate system can be easily mapped to the target coordinate system.

[0055] For some examples, see Figure 4 In actual situations, due to processing accuracy issues, the reference layer 23 may not be parallel to the prism layer 21, and the reference layer 23 may not be parallel to the intermediate layer. However, the central axis of the hollow corner cube prism 211 is still parallel to the side of the prism layer 21. At this time, the X coordinate system of the target is T Axis and Y T The axis may not be parallel to the prism layer 21. The central axis of the hollow corner cube prism 211 may be parallel to the X axis. T O T Y T The plane is not vertical.

[0056] In some examples, the calibration involved in the present disclosure may refer to calibrating the origin of the sensor coordinate system, X D Axis direction, Y DOther relevant values, such as the direction of the axis, the distance between the origin of the sensor coordinate system and the target coordinate system (or the distance between the position sensitive detector 231 and the through hole), can be obtained through calibration, direct measurement, or from a machining drawing. In this case, the attitude probe 20 can be calibrated quickly, thereby improving the measurement accuracy when using the laser tracker 10 and the attitude probe 20.

[0057] In some examples, the calibration involved in the present disclosure may also refer to the calibration of the sensor's X D The direction of the axis and Y D The direction of the axis, the position of the coordinate origin of the sensor coordinate system, and the distance between the coordinate origin of the sensor coordinate system and the target coordinate system (or the distance between the position sensitive detector 231 and the through hole) and other related values can be obtained through calibration, direct measurement, or processing drawings. In this case, the attitude probe 20 can be calibrated quickly, thereby improving the measurement accuracy when using the laser tracker 10 and the attitude probe 20.

[0058] In some examples, the calibration involved in the present disclosure may also refer to determining the distance between the origin of the sensor coordinate system and the target coordinate system (or the distance between the position sensitive detector 231 and the through hole), the origin position of the sensor coordinate system, X D Axis direction, Y D Other relevant values such as the direction of the axis can be obtained by calibration, direct measurement or through processing drawings. In this case, the attitude probe 20 can be calibrated quickly, thereby improving the measurement accuracy when using the laser tracker 10 and the attitude probe 20.

[0059] In some examples, the calibration involved in the present disclosure can also calibrate the coordinate origin position of the sensor coordinate system, calibrate the X D The direction of the axis and Y D Any combination of the direction of the axis and the distance between the coordinate origin of the calibration sensor coordinate system and the target coordinate system can further improve the calibration effect and thus further improve the measurement accuracy when using the laser tracker 10 and the attitude probe 20.

[0060] The following details the coordinate origin position of the sensor coordinate system, the X D The direction of the axis and Y D The process of calibrating the direction of the axis, the distance between the origin of the sensor coordinate system and the target coordinate system. It should be noted that each calibration process can be performed separately.

[0061] The calibration method of the posture probe 20 involved in the present disclosure can also be referred to as a calibration method for the posture probe 20 with a position-sensitive detector 231, a calibration method based on beam rotation, a target calibration method, a calibration method for an auxiliary measurement device, a target sphere calibration method, or a calibration method.

[0062] Figure 5 1 is a flow chart showing a calibration method according to an embodiment of the present disclosure. Figure 6 It is a schematic diagram showing the process of calibrating the coordinate origin of the coordinate system in the calibration method involved in the embodiment of the present disclosure.

[0063] For some examples, see Figure 5 The calibration method may include: calibrating the coordinate origin of the sensor coordinate system (step S100), calibrating the direction of the coordinate axis of the coordinate system (step S200), and calibrating the distance between the position sensitive detector 231 and the through hole (step S300).

[0064] For some examples, see Figure 6 , calibrating the coordinate origin of the sensor coordinate system may include: setting the attitude probe 20 on a rotating platform 32 having a rotating axis (step S101), adjusting the through hole of the transmitting module 35 and the attitude probe 20 to the axis of the rotating axis (step S102), the attitude probe 20 receives the light beam generated by the transmitting module 35, rotating the rotating platform 32 and driving the attitude probe 20 to rotate (step S103), using the position sensitive detector 231 to record the trajectory of the light beam and calibrate the coordinate origin of the coordinate system based on the trajectory (step S104).

[0065] In this case, if the reference layer 23 and the prism layer 21 (middle layer) are not parallel, when the attitude probe 20 rotates on the rotating platform 32, the light beam will move in the position-sensitive detector 231. At the same time, the specific position of the coordinate origin of the coordinate system in the position-sensitive detector 231 can be obtained through the trajectory of the light beam in the position-sensitive detector 231, thereby realizing the calibration of the coordinate origin of the coordinate system, and then the calibration results can be used in subsequent detection tasks to correct the actual measurement values, thereby improving the measurement accuracy of the laser tracker 10.

[0066] Figure 7 3 is a schematic diagram showing a scenario in which the transmitting module 35 and the through hole are adjusted to be on the axis in the calibration method involved in the embodiment of the present disclosure. Figure 8 3 is a schematic diagram showing a scene of calibrating the coordinate origin of a coordinate system in a calibration method according to an embodiment of the present disclosure.

[0067] In some examples, in step S101, the attitude probe 20 can be placed on the rotating platform 32. In some examples, the rotating platform 32 can have a rotation axis and can rotate relative to the base 31 about the rotation axis. Specifically, the rotating platform 32 can be placed on the base 31 via the rotation axis.

[0068] In some examples, the rotating platform 32 may have a horizontal bearing surface. Specifically, the horizontal angle of the bearing surface may be less than a preset value. In some examples, the horizontal angle of the bearing surface may be measured using a level. In this case, the accuracy of the calibration can be improved.

[0069] In some examples, in step S102, the through holes of the transmitting module 35 and the attitude probe 20 can be adjusted to the axis of the rotation axis.

[0070] In some examples, the transmitting module 35 may be a laser collimator. In some examples, the transmitting module 35 may be an instrument capable of emitting a laser beam.

[0071] In some examples, the transmitting module 35 can be located above the attitude probe 20. In some examples, the transmitting module 35 can be located above the attitude probe 20 with its transmitting port aligned with the through-hole of the attitude probe 20. In other words, the attitude probe 20 can be positioned between the transmitting module 35 and the rotating platform 32. In this case, as the rotating platform 32 rotates, the position of the through-hole can remain unchanged. Meanwhile, the laser beam emitted by the transmitting module 35 can continue to pass through the through-hole and reach the position-sensitive detector 231, thereby detecting changes in the position of the laser beam on the position-sensitive detector 231.

[0072] In some examples, in step S103 , the attitude probe 20 may receive the light beam generated by the transmitting module 35 , rotate the rotating platform 32 , and drive the attitude probe 20 to rotate.

[0073] For some examples, see Figure 7 , the transmitting module 35 and the through hole can be adjusted to the axis of the rotating shaft by the following method. When adjusting the transmitting module 35 and the through hole to the axis of the rotating shaft, the fixing frame 33 provided on the base 31 can be used to set the shooting module 34 to a first position, and the first position is located on the axis of the rotating shaft. The lens of the shooting module 34 is aligned with the through hole, and the rotating platform 32 is rotated to drive the posture probe 20 to rotate and use the shooting module 34 to shoot. Based on the position of the through hole, it is determined whether the through hole is located on the axis of the rotating shaft. In this case, since the shooting module 34 is located on the straight line where the rotating shaft is located, it is possible to determine whether the through hole is located on the axis of the rotating shaft.

[0074] In some examples, when the shooting module 34 is located at the first position, the shooting direction of the shooting module 34 may be perpendicular to the carrying surface.

[0075] In some examples, if the position of the through hole changes during the rotation of the attitude probe 20, it can be determined that the attitude probe 20 is not located on the axis of the rotating shaft, and the position of the attitude probe 20 can be readjusted. If the position of the through hole does not change, it can be determined that the attitude probe 20 is located on the axis of the rotating shaft. In this case, it is possible to determine whether the through hole of the attitude probe 20 is located on the axis of the rotating shaft based on the change in the position of the through hole.

[0076] In some examples, if the attitude probe 20 is not located on the axis of the rotating shaft, the position of the attitude probe 20 can be readjusted. In some examples, after adjusting the position of the attitude probe 20, it can be re-determined whether the through hole of the attitude probe 20 is located on the axis of the rotating shaft, and the position of the attitude probe 20 can be repeatedly adjusted until the through hole of the attitude probe 20 is located on the axis of the rotating shaft. In this case, the through hole of the attitude probe 20 can be located on the axis of the rotating shaft.

[0077] For some examples, see Figure 8 After the attitude probe 20 is set on the axis of the rotation shaft, the shooting module 34 can be removed and the transmitting module 35 can be set in the first position. In this case, the transmitting module 35 can be located on the axis of the rotation shaft.

[0078] In some examples, in step S104 , the position sensitive detector 231 may be used to record the trajectory of the light beam and calibrate the origin of the coordinate system based on the trajectory.

[0079] In some examples, the transmitting module 35 emits a laser beam and forms a light spot on the position sensitive detector 231 . When the rotating platform 32 rotates, the light spot moves on the position sensitive detector 231 and forms a track (ie, the track of the light beam on the position sensitive detector 231 ).

[0080] In some examples, the trajectory can be an arc, circle, or ellipse. In this case, the center of the trajectory (e.g., the center of the arc, the center of the circle, or the focus of the ellipse) can be used as the coordinate origin of the sensor coordinate system. In some examples, the trajectory can be a light spot. In this case, the geometric center of the light spot can be used as the coordinate origin of the sensor coordinate system. In this case, the coordinate origin of the sensor coordinate system can be calibrated, and the coordinate origin of the target coordinate system can be calibrated accordingly.

[0081] Figure 9 3 is a schematic diagram showing a flow chart of calibrating the directions of coordinate axes of a coordinate system in a calibration method according to an embodiment of the present disclosure. Figure 10 It is a schematic diagram of a scene showing the directions of coordinate axes of a calibration coordinate system in a calibration method according to an embodiment of the present disclosure. Figure 111 is a top view of a scene when measuring a first target position in a calibration method according to an embodiment of the present disclosure. Figure 12 1 is a top view of a scene when measuring the second target position in the calibration method according to an embodiment of the present disclosure. Figure 13 2 is a schematic diagram illustrating a first target position and a second target position in a position sensitive detector 231 in a calibration method according to an embodiment of the present disclosure.

[0082] In some examples, the calibration method may further include calibrating the directions of coordinate axes of the coordinate system.

[0083] For some examples, see Figure 9 Calibration of the direction of the coordinate axis of the coordinate system may include: placing the attitude adjustment platform 36 on the rotating platform 32, placing the attitude probe 20 on the attitude adjustment platform 36 (step S201), adjusting the attitude of the attitude adjustment platform 36 so that the central axis of the hollow corner cube prism 211 is parallel to the rotating platform 32, setting the transmitting module 35 at the second position of the fixing frame 33 (step S202), the attitude probe 20 receiving the light beam generated by the transmitting module 35, recording the position where the light beam is incident on the position sensitive detector 231 as the first target position (step S203), rotating the rotating platform 32 to rotate the attitude probe 20 by a preset angle, recording the position where the light beam is incident on the position sensitive detector 231 as the second target position (step S204), and calibrating the direction of the coordinate axis of the coordinate system based on the first target position and the second target position (step S205). In this case, the direction of the coordinate axis of the sensor coordinate system can be calibrated to further calibrate the direction of the coordinate axis of the target coordinate system.

[0084] In some examples, in step S201, see Figure 10 , the attitude adjustment platform 36 can be placed on the rotating platform 32, and the attitude probe 20 can be placed on the attitude adjustment platform 36. In this case, the attitude adjustment platform 36 can be used to adjust the horizontality of the attitude probe 20.

[0085] In some examples, the posture adjustment platform 36 may be placed on the base 31 , and the posture probe 20 may be placed on the posture adjustment platform 36 .

[0086] In some examples, when the attitude adjustment platform 36 adjusts the horizontality of the attitude probe 20, the gravity tilt sensor 212 of the attitude probe 20 described above can be used to determine whether the attitude probe 20 is in a horizontal state. Specifically, the attitude adjustment platform 36 can be adjusted until the reading of the gravity tilt sensor 212 is zero.

[0087] In some examples, a level meter may be placed on the top side of the attitude probe 20. In this case, the level meter can be used to determine whether the attitude probe 20 is in a horizontal state. In some examples, the attitude adjustment platform 36 may also be adjusted until the level meter indicates that the attitude probe 20 is in a horizontal state.

[0088] For some examples, see Figure 10 The posture adjustment platform 36 may include a plurality of adjustment screws 361 . In this case, the posture of the posture adjustment platform 36 can be adjusted using the plurality of adjustment screws 361 , thereby adjusting the posture of the posture probe 20 .

[0089] In some examples, in step S202, see Figure 10 The posture adjustment platform 36 can be adjusted so that the central axis of the hollow corner cube 211 is parallel to the rotating platform 32, and the transmitting module 35 can be placed in the second position of the fixed frame 33. In some examples, the second position is located on the central axis. In this case, the light beam emitted by the transmitting module 35 can be aligned with the central axis of the hollow corner cube 211 in the same horizontal plane.

[0090] In some examples, in step S202, see Figure 11 The attitude probe 20 can receive the light beam generated by the transmitting module 35 and record the position where the light beam is incident on the position sensitive detector 231 as the first target position.

[0091] In some examples, the position of the attitude probe 20 can be pre-adjusted so that the first target position is located near the edge of the position sensitive detector 231. In this case, the first target position and the second target position can be separated from each other, thereby having a larger distance between the first target position and the second target position, thereby improving the calibration accuracy.

[0092] In some examples, in step S202, see Figure 12 The rotating platform 32 can be rotated to rotate the attitude probe 20 by a preset angle, and the position where the light beam impinges on the position-sensitive detector 231 is recorded as the second target position. In this case, the second target position can be obtained, and the directions of the coordinate axes of the coordinate system can be subsequently calibrated using the first and second target positions.

[0093] In some examples, after the attitude probe 20 rotates through a preset angle, the attitude of the attitude adjustment platform 36 can be adjusted so that the central axis of the hollow corner cube 211 is parallel to the rotating platform 32. In this case, the attitude probe 20 can be ensured to be in a horizontal state when the first target position and the second target position are obtained, thereby improving the accuracy of the calibration.

[0094] In some examples, after the attitude probe 20 rotates the preset angle, the attitude adjustment platform 36 may not be adjusted and the second target position may be obtained. In this case, the calibration speed can be increased. In some examples, when the attitude adjustment platform 36 is placed on the base 31, the attitude probe 20 can be directly rotated to rotate the attitude probe 20 by the preset angle.

[0095] In some examples, the predetermined angle is smaller than the angle of the hollow corner cube prism 211. In some examples, the predetermined angle is smaller than 90°. In this case, the light beam can be directed onto the position sensitive detector 231 during the rotation of the posture probe 20.

[0096] In some examples, in step S205, see Figure 13 , the directions of the coordinate axes of the coordinate system can be calibrated based on the first target position and the second target position.

[0097] In some examples, the direction of the line connecting the first target position and the second target position can be defined as the direction of the first coordinate axis (X-axis) of the coordinate system, and the direction perpendicular to the line connecting the first target position and the second target position can be defined as the direction of the second coordinate axis (Y-axis) in the position-sensitive detector 231. In this case, the direction of the coordinate axis of the sensor coordinate system can be calibrated, and thus the direction of the target coordinate axis can be calibrated.

[0098] Figure 14 1 is a schematic diagram showing a flow chart of calibrating the distance between the coordinate origin and the through hole in the calibration method according to an embodiment of the present disclosure. Figure 15 3 is a schematic diagram showing the principle of calibrating the distance between the coordinate origin and the through hole in the calibration method involved in the embodiment of the present disclosure.

[0099] In some examples, the calibration method may further calibrate the distance between the coordinate origin and the through-hole. Specifically, the distance between the calibration coordinate origin and the through-hole may be the distance between the coordinate origin of the calibration sensor coordinate system and the through-hole, the distance between the calibration coordinate origin and the through-hole may also be the distance between the coordinate origin of the calibration sensor coordinate system and the coordinate origin of the target coordinate system, and the distance between the calibration coordinate origin and the through-hole may also be the distance between the calibration position-sensitive detector 231 and the through-hole.

[0100] For some examples, see Figure 14Calibrating the distance between the position-sensitive detector 231 and the through-hole may include: emitting a laser beam toward the through-hole of the attitude probe 20 using the laser tracker 10 (step S301), causing the attitude probe 20 to move a preset distance along the second coordinate axis (step S302), recording the horizontal angle of the attitude probe 20 during movement using the laser tracker 10 (step S303), obtaining the distance traveled by the light beam in the position-sensitive detector 231 (step S304), and calibrating the distance between the position-sensitive detector 231 and the through-hole based on the travel distance and the horizontal angle (step S305). In this case, the distance between the position-sensitive detector 231 and the through-hole can be calibrated.

[0101] In some examples, in step S301 , the laser tracker 10 may be used to emit a laser toward a through hole of the gesture probe 20 .

[0102] In some examples, the laser emitted by the laser tracker 10 can be aimed at the geometric center of the position sensitive detector 231. Specifically, the laser tracker 10 can be used to emit a laser beam, and the posture of the posture probe 20 can be adjusted until the laser beam coincides with the central axis of the hollow corner cube prism 211.

[0103] In some examples, in step S302 , the posture probe 20 may be moved a preset distance along the direction of the second coordinate axis.

[0104] In some examples, when the gesture probe 20 moves a preset distance along the direction of the second coordinate axis, the gesture probe 20 does not move along the direction of the first coordinate axis.

[0105] In some examples, in step S303 , the laser tracker 10 may be used to record the horizontal angle of the gesture probe 20 as it moves.

[0106] In some examples, in step S304, the movement distance of the light beam in the position sensitive detector 231 may be obtained. In some examples, the movement distance of the light beam in the direction of the second coordinate axis in the position sensitive detector 231 may be obtained.

[0107] In some examples, in step S305 , the distance between the position sensitive detector 231 and the through hole may be calibrated based on the moving distance and the horizontal angle.

[0108] For some examples, see Figure 15, the posture probe 20 (or through hole) moves a preset distance along the first position. Since the laser tracker 10 tracks the posture probe 20, the light beam (laser beam) emitted by the laser tracker 10 will also move. In some examples, the horizontal angle can be used to describe the movement of the light beam, or the moving distance angle of the light beam can be used to describe the movement of the light beam. It should be noted that the moving distance of the light beam here refers to the moving distance of the light spot formed by the light beam in the position sensitive detector 231. The moving distance can be the moving distance relative to the position sensitive detector 231. At this time, the moving distance of the light beam can refer to the moving distance L of the light beam (light spot) in the position sensitive detector 231. The moving distance can also be the moving distance relative to the space. At this time, the moving distance of the light beam can refer to the actual moving distance of the light beam (light spot) in space.

[0109] For some examples, see Figure 15 , the distance between the position sensitive detector 231 and the through hole satisfies the formula:

[0110]

[0111] Where d represents the distance between the coordinate origin (the coordinate origin of the sensor coordinate system) and the through-hole, L represents the distance the light beam moves in the position-sensitive detector 231, and α represents the horizontal angle. In this case, the distance between the position-sensitive detector 231 and the through-hole can be obtained, and thus the distance between the position-sensitive detector 231 and the through-hole can be calibrated.

[0112] In some examples, L may be acquired by the position sensitive detector 231 , and α may be acquired by the laser tracker 10 .

[0113] In some examples, steps S301 to S305 may be repeated to obtain multiple distances between the position sensitive detector 231 and the through hole, and the average of the distances between the position sensitive detector 231 and the through hole is calculated, and the average is used as the distance between the position sensitive detector 231 and the through hole. In this case, the calibration accuracy can be improved.

[0114] Although the present disclosure has been described in detail above with reference to the accompanying drawings and examples, it will be understood that the above description does not limit the present disclosure in any form. Those skilled in the art may modify and change the present disclosure as needed without departing from the spirit and scope of the present disclosure, and such modifications and variations all fall within the scope of the present disclosure.

Claims

1. A method for calibrating a posture probe, the posture probe comprising a reference layer provided with a position-sensitive detector, a prism layer provided with hollow corner cube prisms, and an intermediate layer provided between the reference layer and the prism layer, the intermediate layer comprising a pinhole plate provided with a through hole, when the posture probe receives a light beam, the light beam passes through the hollow corner cube prisms and the through hole to reach the position-sensitive detector, the calibration method is a method for calibrating the coordinate system of the posture probe, characterized in that: include: The attitude probe is arranged on a rotating platform having a rotating axis, the rotating platform is configured to rotate relative to a base with the rotating axis as the rotation center, the through holes of the transmitting module and the attitude probe are adjusted to the axis of the rotating axis, the attitude probe receives the light beam generated by the transmitting module, the rotating platform is rotated to drive the attitude probe to rotate, the trajectory of the light beam is recorded by the position sensitive detector, and the coordinate origin of the coordinate system is calibrated based on the trajectory; Placing a posture adjustment platform on the rotating platform, placing the posture probe on the posture adjustment platform, adjusting the posture of the posture adjustment platform so that the central axis of the hollow corner cube prism is parallel to the rotating platform, setting the transmitting module at a second position of a fixing bracket, the fixing bracket being set on the base, the second position being located on the central axis of the hollow corner cube prism, the posture probe receiving the light beam generated by the transmitting module, recording the position where the light beam is incident on the position sensitive detector as a first target position, rotating the rotating platform so that the posture probe rotates a preset angle, recording the position where the light beam is incident on the position sensitive detector as a second target position, and calibrating the direction of the coordinate axis of the coordinate system based on the first target position and the second target position; A laser tracker is used to emit a laser toward the through hole of the attitude probe, so that the attitude probe moves a preset distance along the direction of the second coordinate axis, and the laser tracker is used to record the horizontal angle of the attitude probe during movement, and the movement distance of the light beam in the position sensitive detector is obtained. The distance between the position sensitive detector and the through hole is calibrated based on the movement distance and the horizontal angle, wherein: Let the direction of the line connecting the first target position and the second target position be the direction of the first coordinate axis among the coordinate axes of the coordinate system, and in the position sensitive detector, the direction perpendicular to the direction of the line connecting the first target position and the second target position be the direction of the second coordinate axis among the coordinate axes of the coordinate system, The distance between the coordinate origin and the through hole is acquired based on the moving distance and the horizontal angle.

2. The calibration method according to claim 1, wherein: When the transmitting module and the through hole are adjusted to the axis of the rotating shaft, The camera module is set at a first position by using a fixing frame set on the base, wherein the first position is located on the axis of the rotating shaft. Align the lens of the shooting module with the through hole, The rotating platform is rotated to drive the attitude probe to rotate and the shooting module is used to shoot, and based on the position of the through hole, it is determined whether the through hole is located on the axis of the rotating shaft.

3. The calibration method according to claim 1, wherein: When the attitude probe rotates, If the position of the through hole changes, it is determined that the attitude probe is not located on the axis of the rotating shaft, and the position of the attitude probe is readjusted. If the position of the through hole does not change, it is determined that the attitude probe is located on the axis of the rotation shaft.

4. The calibration method according to claim 2, wherein: After the attitude probe is set on the axis of the rotation shaft, The shooting module is disassembled and the transmitting module is placed at the first position.

5. The calibration method according to claim 1, wherein: After the posture probe rotates by a preset angle, the posture of the posture adjustment platform is adjusted so that the central axis of the hollow corner cube is parallel to the rotating platform.

6. The calibration method according to claim 1, wherein: The preset angle is smaller than 90°.

7. The calibration method according to claim 1, characterized in that: The distance between the position sensitive detector and the through hole satisfies the formula: Wherein, d represents the distance between the coordinate origin and the through hole, L represents the moving distance, and α represents the horizontal angle.

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