CN116165673B

CN116165673B - Six-dimensional probe based on backward tracking

Info

Publication number: CN116165673B
Application number: CN202211591676.3A
Authority: CN
Inventors: 张和君; 廖学文; 冯福荣; 陈源; 吴兴发; 张海叶; 常立超
Original assignee: Chotest Technology Inc
Current assignee: Chotest Technology Inc
Priority date: 2022-12-12
Filing date: 2022-12-12
Publication date: 2023-09-22
Anticipated expiration: 2042-12-12
Also published as: CN117331090A; CN117331091A; CN116165673A

Abstract

The present disclosure describes a six-dimensional probe based on back tracking, comprising: the probe comprises a fixed base, a target, a probe position sensing unit, a probe tracking control unit and a probe gravity alignment unit, wherein the target is provided with a through hole and is configured to reflect laser or scattered light beams emitted by a tracker to the tracker, the probe position sensing unit is configured to receive the laser passing through the through hole and obtain sensing information, the probe tracking control unit is configured to control the posture of the target based on the sensing information so as to align the target with the tracker, the probe tracking control unit comprises a first rotating mechanism for controlling the target to rotate along a first direction and a second rotating mechanism for controlling the target to rotate along a second direction, and the probe gravity alignment unit is arranged on the fixed base and is configured to measure the posture of the target. Therefore, the target can be reversely tracked through the probe position sensing unit, and the receivable angle range of the probe is enlarged.

Description

Six-dimensional probe based on backward tracking

Technical Field

The invention relates to an intelligent manufacturing equipment industry, in particular to a six-dimensional probe based on back tracking.

Background

In the precision industry and in the measurement field, people often need to test the assembled object by using a precision instrument to improve the assembly precision when assembling, and also need to calibrate the machine after assembling. When three-dimensional coordinate measurement is performed on a target object or a certain target point on the target object, it is also necessary to measure the posture of the target object or a certain target point, and therefore a posture detection device capable of simultaneously measuring the three-dimensional coordinate and the posture of the target is required.

The commonly used posture detecting apparatus includes a probe head for emitting and receiving a laser beam and a probe head provided at a workpiece and for reflecting the laser beam, measures three-dimensional coordinates of the probe head using the laser beam, and acquires a posture of the probe head using a light source provided at the probe head. However, when the pose of the workpiece is changed, the laser beam may exceed the acceptable angle range (typically plus or minus 45 °) of the probe, so that the mirror of the probe cannot receive the laser beam, thereby affecting the measurement result. For this reason, the prior art discloses a posture detecting device that causes a probe to actively track (i.e., back track) a probe head. For example, chinese patent publication No. CN112424563a discloses a multidimensional measuring system for precisely calculating the position and orientation of a dynamic object, actively tracking a laser beam unit (i.e., a stylus) with a target (i.e., a probe), and expanding an acceptable angular range of a reflecting element by changing the posture of the probe.

However, in this solution, at least three rotation mechanisms are required to be provided in the probe so that the probe can rotate around the pitch axis, the yaw axis and the roll axis, respectively, and at the same time, measurement with a gyroscope and a plurality of levels is required to confirm the rotation of the roll axis, resulting in a complicated structure of the probe.

Disclosure of Invention

The present disclosure has been made in view of the above-described circumstances, and an object thereof is to provide a probe structure that can realize backward tracking, expand the receivable angle of the probe, and have a simple structure.

The present disclosure provides a six-dimensional probe based on back tracking, which is a six-dimensional probe for being mounted on a target and cooperating with a laser tracker to obtain a position and an attitude of the target, comprising: the probe comprises a fixed base, a target, a probe position sensing unit, a probe tracking control unit and a probe gravity alignment unit, wherein the fixed base is configured to mount the probe on the target, the target is provided with a through hole and is configured to reflect laser or scattered light beams emitted by the laser tracker to the laser tracker, the probe position sensing unit is configured to receive the laser passing through the through hole and obtain sensing information, the probe tracking control unit is configured to control the posture of the target based on the sensing information so as to enable the target to be aligned with the laser tracker, the probe tracking control unit comprises a first rotating mechanism for controlling the target to rotate along a first direction and a second rotating mechanism for controlling the target to rotate along a second direction, and the probe gravity alignment unit is arranged on the fixed base and is configured to measure the posture of the target.

In this case, the back tracking of the target can be achieved, the receivable angle range of the probe is enlarged, and at the same time, since the target is continuously aligned with the laser beam during the back tracking, the direction vector of the laser beam in the target coordinate system (described later) can be conveniently represented by the angle at which the target rotates in the first direction and the angle at which the target rotates in the second direction. The euler angle of the portion of the target can be acquired by the probe gravity alignment unit, and the transformation relationship between the target coordinate system and the target coordinate system (described later) can also be obtained based on the angle measured by the probe gravity alignment unit.

In addition, in the six-dimensional probe related to the present disclosure, optionally, the six-dimensional probe includes a probe angle measurement unit including a first probe angle measurement unit configured to measure a rotation angle of the target rotating in the first direction and a second probe angle measurement unit configured to measure a rotation angle of the target rotating in the second direction. In this case, the rotation angle of the target rotating in the first direction and the rotation angle of the target rotating in the second direction can be obtained, and the direction vector of the laser beam in the target coordinate system can be calculated based on the rotation angle of the target rotating in the first direction and the rotation angle of the target rotating in the second direction.

In addition, in the six-dimensional probe related to the present disclosure, optionally, the probe gravity alignment unit includes a first inclinometer and a second inclinometer, an installation direction of the first inclinometer is perpendicular to an extension direction of a rotation shaft of the first rotation mechanism, an installation direction of the second inclinometer is parallel to an extension direction of the rotation shaft of the second rotation mechanism, and an installation direction of the first inclinometer is perpendicular to an installation direction of the second inclinometer. In this case, since the sensitive axis of the probe gravity alignment unit is matched with the rotation axis of the probe tracking control unit, the transformation formulas of the target coordinate system and the target coordinate system can be simplified, the calculation speed can be improved, and the measurement accuracy can be improved. Meanwhile, the target inclination angle measured by the first inclinometer can be used as the pitch angle of a fixed base (target), and the target inclination angle measured by the second inclinometer can be used as the roll angle of the fixed base (target).

In addition, in the six-dimensional probe according to the present disclosure, optionally, the first rotation mechanism is provided on the fixed base, and the first rotation mechanism includes a first rotation shaft, a first bearing matched with the first rotation shaft, a support arm linked with the first rotation shaft, and a first driving motor that drives the first rotation shaft to rotate. In this case, the first rotation shaft can be driven to rotate by the first driving motor, and the support arm can be driven to rotate around the first rotation shaft, and the target can be driven to rotate around the first rotation shaft by the support arm.

In addition, in the six-dimensional probe according to the present disclosure, optionally, the second rotation mechanism is provided on the support arm, the second rotation mechanism includes a second rotation shaft, a second bearing matched with the second rotation shaft, and a second driving motor that drives the second rotation shaft to rotate, and the target is provided on the second rotation shaft and linked with the second rotation shaft. Under the condition, the second rotating shaft can be arranged on the supporting arm through the second bearing, and then the supporting arm can drive the second rotating shaft and the target arranged on the second rotating shaft to rotate around the first rotating shaft, meanwhile, the second rotating shaft can be driven by the second driving motor to rotate, and then the target is driven to rotate around the second rotating shaft, so that the second rotating shaft can drive the target to rotate along the second direction.

In addition, in the six-dimensional probe according to the present disclosure, optionally, the target includes a reference layer configured to mount the probe position sensing unit, a prism layer provided with a hollow pyramid prism, and an intermediate layer between the reference layer and the prism layer and having the through hole. In this case, the laser beam can be returned to the laser tracker in a direction opposite to the incident direction, and the distance from the mechanical zero point of the laser tracker to the center of the pyramid, i.e., the distance between the laser emitting unit and the target, can be measured. Meanwhile, when the laser beam emitted by the laser emission unit enters along the optical axis of the hollow pyramid prism, namely, the target is aligned with the laser emission unit, the laser beam can pass through the through hole and form a specific light spot at a specific position behind the through hole, and then whether the target is aligned with the laser emission unit can be determined according to whether the light spot exists at the specific position behind the through hole.

In addition, in the six-dimensional probe according to the present disclosure, optionally, a filter is provided between the through hole and the probe position sensing unit at the reference layer. In this case, light outside a specific wavelength range (for example, the wavelength of the laser beam formed by the laser emitting unit) can be filtered so that the energy of the spot formed by the probe position sensing unit through the through hole comes from the laser beam formed by the laser emitting unit, whereby the influence of the interference of the ambient light or the light emitting unit can be reduced, thereby improving the detection accuracy of the laser beam azimuth.

In addition, in the six-dimensional probe related to the present disclosure, optionally, the probe position sensing unit is disposed on the reference layer, the probe position sensing unit includes a photosurface, the photosurface is perpendicular to an axis of the hollow pyramid prism, and the probe position sensing unit is configured to detect a moving distance of the laser light passing through the through hole with respect to a preset zero point through the photosurface and obtain the sensing information. In this case, since the light-sensing surface is perpendicular to the two axes of the target coordinate system, the position of the spot acquired by the probe position sensing unit can be used to represent the posture of the target, and the calculation can be simplified.

In addition, in the six-dimensional probe related to the present disclosure, optionally, the vertex of the hollow pyramid prism is located at an intersection point of the axis of the first rotation shaft and the axis of the second rotation shaft. In this case, the calculation can be simplified, the calculation speed can be increased, and the calculation accuracy can be improved.

In addition, in the six-dimensional probe related to the present disclosure, optionally, an axis of the first rotation shaft is perpendicular to a sensitive plane of the probe gravity alignment unit, and an axis of the second rotation shaft is parallel to the sensitive plane. In this case, since the sensitive axis of the probe gravity alignment unit is matched with the rotation axis of the probe tracking control unit, the transformation formulas of the target coordinate system and the target coordinate system can be simplified, the calculation speed can be improved, and the measurement accuracy can be improved. Meanwhile, the target inclination angle measured by the first inclinometer can be used as the pitch angle of a fixed base (target), and the target inclination angle measured by the second inclinometer can be used as the roll angle of the fixed base (target).

According to the present disclosure, a probe structure is provided that enables backward tracking, enlarges the receivable angle of the probe, and is simple in structure.

Drawings

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

fig. 1 is a schematic view showing an application scenario of a six-dimensional posture detection apparatus according to an example of the present disclosure.

Fig. 2 is a schematic diagram showing a six-dimensional probe of a six-dimensional posture detection device according to an example of the present disclosure.

Fig. 3 is a schematic diagram showing a first plane, a first direction, an axis of a first rotation shaft, a second plane, a second direction, and an axis of a second rotation shaft to which examples of the present disclosure relate.

Fig. 4 is a schematic cross-sectional view showing the M-M' position in fig. 2 of a six-dimensional probe of the six-dimensional posture detection device according to the example of the present disclosure.

Fig. 5 is a schematic cross-sectional view showing the target and the second rotation axis of the six-dimensional posture detection device according to the example of the present disclosure at the N-N' position in fig. 2.

Fig. 6 is a front view showing a partial structure of a six-dimensional probe of the six-dimensional posture detection device according to the example of the present disclosure.

Fig. 7 is a schematic sectional view of the O-O' position in fig. 6 showing a partial structure of a six-dimensional probe of the six-dimensional posture detection device according to the example of the present disclosure.

Fig. 8 is a schematic cross-sectional view of the O-O' position in fig. 6 showing a partial structure of a target of the six-dimensional posture detection device according to the example of the present disclosure.

Fig. 9 is a bottom view showing a partial structure of a six-dimensional probe of the six-dimensional posture detection device according to the example of the present disclosure.

Detailed Description

Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the following description, the same members are denoted by the same reference numerals, and overlapping description thereof is omitted. In addition, the drawings are schematic, and the ratio of the sizes of the components to each other, the shapes of the components, and the like may be different from actual ones.

The disclosure relates to a six-dimensional gesture detection device based on back tracking, which can be used for measuring six-dimensional coordinates of a target, and can comprise a laser tracker and a probe matched with the laser tracker, and the laser tracker is actively tracked through the probe. In this case, the probe is simultaneously capable of tracking the laser tracker in reverse, and the probe is capable of continuously reflecting the laser beam emitted from the laser tracker during movement.

In some examples, a six-dimensional gesture detection device based on back tracking may also be referred to as, a six-dimensional gesture detection device, an active back tracking six-dimensional gesture detection device, a six-dimensional gesture detection device or gesture detection device, or the like.

The disclosure relates to a six-dimensional probe based on back tracking, which comprises a target, a probe position sensing unit arranged on the target, a first rotating mechanism for controlling the target to horizontally rotate based on sensing information of the probe position sensing unit, and a second rotating mechanism for controlling the target to rotate in a pitching mode. Under the condition, whether the target is aligned to the laser beam can be judged by using the sensing information of the probe position sensing unit, and the target is controlled to be aligned to the laser tracker by using the first rotating mechanism and the second rotating mechanism, so that the target is reversely tracked, and the receivable angle range of the six-dimensional probe is enlarged.

The disclosure relates to a six-dimensional probe based on back tracking, comprising a target, a fixed base for installing the probe on the target and a probe gravity alignment unit arranged on the fixed base. In this case, since the stationary base is mounted to the target, the euler angle of a portion of the target can be acquired by the probe gravity alignment unit.

The disclosure relates to a six-dimensional probe based on back tracking, which comprises a fixed base, a target, a probe position sensing unit, a probe tracking control unit and a probe gravity alignment unit, wherein the fixed base is configured to mount the six-dimensional probe on a target, the target is provided with a through hole and is configured to reflect laser or scattered light beams emitted by a laser tracker to the tracker, the probe position sensing unit is configured to receive the laser passing through the through hole and obtain sensing information, the probe tracking control unit is configured to control the posture of the target based on the sensing information so as to enable the target to be aligned with the tracker, the probe tracking control unit comprises a first rotating mechanism for controlling the target to rotate along a first direction and a second rotating mechanism for controlling the target to rotate along a second direction, and the probe gravity alignment unit is arranged on the fixed base and is configured to measure the posture of the target. In this case, the back tracking of the target can be realized, the receivable angle range of the six-dimensional probe is enlarged, and at the same time, since the target is continuously aligned with the laser beam in the back tracking process, the direction vector of the laser beam in the target coordinate system (described later) can be conveniently represented by the angle of rotation of the target in the first direction and the angle of rotation in the second direction. The euler angle of the portion of the target can be acquired by the probe gravity alignment unit, and the transformation relationship between the target coordinate system and the target coordinate system (described later) can also be obtained based on the angle measured by the probe gravity alignment unit.

In some examples, a six-dimensional probe based on back tracking may also be referred to as a probe, an attitude probe, an auxiliary measurement device, a receiver, a reflector, a target ball, or the like.

In some examples, six-dimensional coordinates (i.e., 6D coordinates) of the target may refer to three position coordinates and three pose angles (i.e., euler angles) of the target in space. In other words, the six-dimensional posture detection apparatus may be used for spatial position measurement and spatial posture measurement of a target, wherein the spatial position measurement corresponds to a spatial position of the target, the spatial position may be represented by a position coordinate of the target, the spatial posture measurement corresponds to a spatial posture of the target, the spatial posture may be represented by an euler angle of the target, and the euler angle may include a yaw angle, a pitch angle, and a roll angle. In some examples, the position coordinates of the target may be made the position coordinates of the target. In some examples, the position coordinates of the target may be obtained based on position coordinate calculations of the target.

In some examples, back tracking may refer to a six-dimensional probe in a six-dimensional pose detection device actively tracking a laser tracker. In some examples, the six-dimensional probe actively tracking the laser tracker may be understood in the following manner, since the laser tracker may include a laser emitting unit (described later) that emits a laser beam, the six-dimensional probe may include a target that reflects the laser beam and has a through-hole, and when at least a portion of the laser beam emitted by the laser emitting unit passes through the through-hole and is parallel to an optical axis of the target, the target (or the six-dimensional probe) may be considered to be aligned with the laser emitting unit (or the laser tracker). In the process of moving the target or changing the posture of the target, the six-dimensional probe can be considered to track reversely (namely, the six-dimensional probe actively tracks the laser tracker) by controlling the posture of the target so that the six-dimensional probe is continuously aligned with the laser emitting unit.

In addition, descriptions of orientations, such as "front", "back", etc., are included with respect to the present disclosure. For targets or other components or units disposed on the targets (e.g., via or probe position sensing units, etc.), "front" may refer to the direction from the target to the laser tracker when the target is aligned with the laser tracker; "rear" may refer to the direction from the laser tracker pointing toward the target when the laser tracker is aligned with the target.

Fig. 1 is a schematic view showing an application scenario of a six-dimensional posture detection apparatus according to an example of the present disclosure. In some examples, referring to fig. 1, a six-dimensional pose detection device may include a laser tracker 1 and a six-dimensional probe 2 that cooperates with the laser tracker 1 to obtain the position and pose of a target.

In some examples, the six-dimensional probe 2 may be mounted to a target. In some examples, at least a portion of the six-dimensional probe 2 (e.g., a stationary base 22 described later) may remain relatively stationary with respect to the target while the six-dimensional probe 2 is mounted to the target. In some examples, the six-dimensional probe 2 may include a target 21 and a stationary base 22 (described later) that positions the six-dimensional probe 2 to the target. In this case, the position and posture of the target can be acquired with the six-dimensional probe 2 provided to the target in cooperation with the laser tracker 1.

In some examples, the target may be a workpiece, or any object that requires measurement of spatial position and/or spatial pose.

In some examples, when using a six-dimensional pose detection device, the laser tracker 1 may be provided independently of the six-dimensional probe 2. In some examples, the laser tracker 1 may be set on the ground and the six-dimensional probe 2 may be set on the target. In this case, the spatial position of the six-dimensional probe 2 can be captured by the laser tracker 1 provided on the ground.

In some examples, the laser tracker 1 may include a laser emitting unit, which may be configured to emit a laser beam. In some examples, the laser tracker 1 may receive a laser beam emitted by a laser emitting unit and reflected by the target 21. In this case, the distance of the target 21 from the laser tracker 1 can be obtained using the reflected laser beam.

In some examples, the laser emitting unit may be a helium-neon laser or a solid state laser.

In some examples, the laser tracker 1 may include a laser firing unit and a tracking head tracking control unit that controls the alignment of the laser firing unit with the target 21. In other words, the tracking head tracking control unit may be configured to control the emission direction of the laser emission unit so that the laser emission unit tracks the six-dimensional probe 2. In this case, the laser emission unit can be controlled to be aligned with the six-dimensional probe 2 at any time, and the laser tracker 1 can be made to receive the laser beam reflected by the target 21 in real time during the movement of the target.

In some examples, the tracking head tracking control unit may drive the laser emitting unit to rotate about a tracking head horizontal axis of rotation and a tracking head pitch axis of rotation. In some examples, the axis of the tracking head horizontal rotation axis and the axis of the tracking head pitch rotation axis are perpendicular and intersect. In some examples, the laser tracker device coordinate system may be established based on the axis of the tracking head horizontal rotation shaft and the axis of the tracking head pitch rotation shaft, for example, the laser tracker device coordinate system may be made to have an intersection point of the axis of the tracking head horizontal rotation shaft and the axis of the tracking head pitch rotation shaft as an origin, a direction of the axis of the tracking head horizontal rotation shaft as a Z-axis direction, a direction of the axis of the tracking head pitch rotation shaft as a Y-axis direction, and a direction perpendicular to the axis of the tracking head horizontal rotation shaft and the axis of the tracking head pitch rotation shaft as an X-axis direction.

In some examples, the laser tracker 1 may comprise a tracking head angle measurement unit, which may be configured to measure the rotation angle of the laser emitting unit under the control of a tracking head tracking control unit. In this case, the rotation angle of the laser emitting unit can be obtained, and the spatial position of the target 21 can be calculated based on the rotation angle of the laser emitting unit and the distance between the laser emitting unit and the target 21. Meanwhile, the rotation angle of the laser emitting unit under the control of the tracking head tracking control unit can be used for representing the direction vector of the laser beam in the coordinate system of the laser tracker device.

In some examples, the laser tracker 1 may include a tracking head gravity alignment unit, which in some examples may be used to measure the tilt angle of the laser emitting unit relative to the horizontal. In some examples, the tracking head gravity alignment unit may be configured to align a direction vector of the laser beam in the laser tracker device coordinate system to the target coordinate system, wherein alignment may refer to finding coordinates of an arbitrary unit in one coordinate system using a transformation relationship in a different coordinate system and the coordinates of the arbitrary unit in the other coordinate system.

In some examples, the target coordinate system may be a coordinate system established based on a direction of gravity, e.g., in an orthogonal axis of the target coordinate system, the Z-axis may be parallel to the direction of gravity and the X-axis and Y-axis may be perpendicular to the direction of gravity. In this case, the spatial positions of the respective coordinate systems can be aligned to the target coordinate system based on the relationship of the different coordinate systems (for example, the laser tracker device coordinate system and the target coordinate system) and the gravity, in the actual process, it is necessary to calculate the yaw angle of the target using the direction vector of the laser beam in the different target coordinate systems and the transformation relationship between the coordinates of the different target coordinate systems, and at the same time, it is difficult to directly obtain the transformation relationship of the laser tracker device coordinate system and the target coordinate system, to align the direction vector of the laser beam to the target coordinate system, and to express the transformation relationship between the target coordinate system and the target coordinate system using the target tilt angle, an equation about the direction vector of the laser beam can be established, and thus the unknown yaw angle can be solved by the equation.

In some examples, taking the example that the tracking head gravity alignment unit may include two single-axis accelerometers, and the axes of sensitivity of the two single-axis accelerometers are orthogonal, the tracking head gravity alignment unit may include a single-axis accelerometer a and a single-axis accelerometer b, wherein the axes of sensitivity of the single-axis accelerometer a and the single-axis accelerometer b may be in the same plane, the plane in which the axes of sensitivity of the single-axis accelerometer a and the single-axis accelerometer b lie may be perpendicular to the tracking head horizontal rotation axis, the axes of sensitivity of the single-axis accelerometer a may be parallel to the tracking head pitch rotation axis, and the axes of sensitivity of the single-axis accelerometer b may be perpendicular to the tracking head pitch rotation axis. In this case, since the sensitive axis of the tracking head gravity alignment unit is matched with the rotation axis of the tracking head tracking control unit, the transformation formulas of the laser tracker device coordinate system and the target coordinate system can be simplified, the calculation speed can be improved, and the measurement accuracy can be improved. However, the disclosure is not limited thereto, and in other examples, the positional relationship of the axes of sensitivity of the two single axis accelerometers to the axis of rotation of the tracking head pitch may not be parallel or perpendicular.

In some examples, six-dimensional probe 2 may be any device capable of reflecting a light beam in a manner opposite in direction of incidence.

Fig. 2 is a schematic diagram showing a six-dimensional probe 2 of a six-dimensional posture detection device according to an example of the present disclosure. Fig. 3 is a schematic diagram showing a first plane S1, a first direction D1, an axis A1 of the first rotation shaft 2311, a second plane S2, a second direction D2, and an axis A2 of the second rotation shaft 2321, to which examples of the present disclosure relate. Fig. 4 is a schematic cross-sectional view showing the M-M' position in fig. 2 of the six-dimensional probe 2 of the six-dimensional posture detection device according to the example of the present disclosure. Fig. 5 is a schematic cross-sectional view showing the target 21 and the second rotation axis 2321 of the six-dimensional posture detection device according to the example of the present disclosure at the N-N' position in fig. 2. Fig. 6 is a front view showing a partial structure of the six-dimensional probe 2 of the six-dimensional posture detection device according to the example of the present disclosure.

Fig. 7 is a schematic sectional view of the O-O' position in fig. 6 showing a partial structure of the six-dimensional probe 2 of the six-dimensional posture detection device according to the example of the present disclosure. Fig. 8 is a schematic sectional view of the O-O' position in fig. 6 showing a partial structure of the target 21 of the six-dimensional posture detection device according to the example of the present disclosure. Fig. 9 is a bottom view showing a partial structure of the six-dimensional probe 2 of the six-dimensional posture detection device according to the example of the present disclosure.

In some examples, referring to fig. 2, 3, 4, 6, and 7, the six-dimensional probe 2 can include a target 21 and a stationary base 22. In some examples, the target 21 may be used to reflect a light beam and the stationary base 22 may be configured to mount the six-dimensional probe 2 to the target. In this case, the six-dimensional probe 2 can be fixed to the target by the fixing base 22, and the six-dimensional probe 2 can be interlocked with the target, so that the position and posture of the target 21 can be determined based on the light beam (including the laser beam and the scattered light beam) reflected by the target 21, and the position (i.e., the position and posture of the target) of the fixing base 22 can be determined based on the position and posture of the target 21.

In some examples, the target 21 may be configured to reflect a laser beam or scatter a beam. In some examples, the targets 21 may have through holes 2122 (see fig. 5). In some examples, the through hole 2122 may be configured to detect whether the laser beam emitted by the laser emitting unit is emitted to the probe position sensing unit 2131 of the target 21.

In some examples, referring to fig. 2, 3, and 4, in some examples, the structure of the target 21 may be a symmetrical structure, e.g., may be symmetrical about the second plane S2 in fig. 3.

In some examples, the target 21 may have a multi-layered structure. For example, the target 21 may comprise a three-layer structure. Specifically, the target 21 may include a prism layer 211, an intermediate layer 212, and a reference layer 213 (see fig. 8). In some examples, the intermediate layer 212 may be disposed between the prism layer 211 and the reference layer 213. In some examples, the target 21 may include a prism layer 211, an intermediate layer 212, and a reference layer 213 disposed front to back.

In some examples, referring to fig. 8, the prism layer 211 may be provided with a mirror 2111 having a cutout. For example, the notched mirror 2111 may be a solid pyramid prism, a hollow pyramid prism, or a hollow optical retroreflector. In this case, the laser beam can be returned to the laser tracker 1 in a direction opposite to the incident direction, and thus the distance from the mechanical zero point of the laser tracker 1 to the center of the pyramid, that is, the distance between the laser emitting unit and the target 21 can be measured. In some examples, the mechanical zero point may refer to an origin of a laser tracker device coordinate system, the pyramid center may be the origin of a target coordinate system, in other words, the laser tracker device coordinate system may be established with the mechanical zero point as the origin, and the target coordinate system may be established with the pyramid center as the origin.

In some examples, the mechanical zero point may refer to the intersection of the tracking head horizontal axis of rotation and the tracking head pitch axis of rotation, thereby enabling simplified operation. The present disclosure is not limited thereto and the mechanical zero point may be any location.

In some examples, the pyramid center may refer to the vertex V of the mirror 2111 with the notch. For example, the vertex V of the mirror may refer to the vertex V of the corner cube in fig. 8. In some examples, the position coordinates of the target 21 may refer to position coordinates of the center of the pyramid. In some examples, the diameter of the incision may be on the order of 1.0-2.0 mm (e.g., the diameter of the incision may be 1.0mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, or 2.0 mm), although the present disclosure is not limited to such an incision, as the diameter of the incision may be less than 1.0mm or greater than 2.0mm, as well as the diameter of the incision may have greater or lesser precision.

In some examples, referring to fig. 8, the plane of the kerf Sc may be parallel to the plane of incidence Si, which may refer to the plane of incidence of the laser beam on the mirror 2111 having the kerf, where the kerf is formed. In this case, at least a part of the incident laser beam is allowed to be projected to the rear probe position sensing unit 2131 through the vertex V.

In some examples, the notched mirror 2111 can be a hollow cube corner prism. In this case, when an incident light beam enters the hollow pyramid prism, the refraction of the light beam can be reduced by plane reflection, and thus the loss of light energy can be reduced, and the light path complexity due to refraction can be reduced, thereby reducing the computational complexity.

In some examples, the hollow pyramid prism may be formed as a two-by-two perpendicular combination of three planar mirrors. In this case, the direction of the outgoing light ray can be parallel to the direction of the incoming light ray after the incoming light beam is reflected in sequence by the three plane mirrors. However, the present disclosure is not limited thereto, and the hollow pyramid prism may be any element capable of reflecting a light beam in a manner opposite to the incident direction.

In some examples, the vertex V of the hollow corner cube may be located in the intermediate layer 212. In some examples, the body of the hollow cube-corner prism may be located in the prism layer 211.

In some examples, the target 21 may include an intermediate layer 212 disposed behind the prism layer 211.

In some examples, referring to fig. 8, the optical axis Ao of the hollow pyramid prism may be made the optical axis Ao of the target 21. In some examples, the through hole 2122 may lie on a line along which the optical axis Ao of the target 21 lies. In this case, when the laser beam emitted from the laser emitting unit is incident along the optical axis Ao of the hollow pyramid prism, that is, when the target 21 is aligned with the laser emitting unit, the laser beam can pass through the through hole 2122 and a specific spot can be formed at a specific position (for example, a preset zero point described later) behind the through hole 2122, and thus whether the target 21 is aligned with the laser emitting unit can be determined according to whether there is a spot at the specific position behind the through hole 2122.

In some examples, a small hole plate 2121 (see fig. 5) may be provided in the intermediate layer 212, and a through hole 2122 may be provided in the small hole plate 2121. In some examples, the through hole 2122 located in the aperture plate 2121 may also be located at the vertex V of the notched mirror 2111. In some examples, the through hole 2122 may be disposed on a line on which the optical axis Ao of the hollow pyramid prism is located in the small hole plate 2121, and the through hole 2122 may be oriented on a line on which the optical axis Ao of the hollow pyramid prism is located.

In some examples, the aperture plate 2121 may be an aluminum plate with through holes 2122. However, the present disclosure is not limited thereto, and the constituent material of the small hole plate 2121 may be composed of a metal material such as iron, copper, stainless steel, or tantalum, or a non-metal material such as silicon, graphite, oxide, or carbide. In some examples, the aperture plate 2121 may be a pinhole aperture. In some examples, the shape of the through hole 2122 may be any shape, for example, the shape of the through hole 2122 may be any shape such as polygonal, elliptical, or circular. Preferably, the through hole 2122 may be circular in shape.

In some examples, the size of the through hole 2122 may be smaller than the cross-sectional size of the laser beam, in which case at least a portion of the laser beam can be passed through the through hole 2122 and allowed to reach the reference layer 213 after passing through hole 2122 to form a spot.

In some examples, referring to fig. 5 and 7, the target 21 may include a filter 2123. In some examples, the filter 2123 may be disposed between the aperture plate 2121 and the probe position sensing unit 2131, in other words, the filter 2123 may be disposed behind the aperture plate 2121. In this case, light outside a specific wavelength range (for example, the wavelength of the laser beam formed by the laser emitting unit) can be filtered so that the energy of the spot formed by the through hole 2122 and at the probe position sensing unit 2131 comes from the laser beam formed by the laser emitting unit, whereby the influence of interference of ambient light or other light sources can be reduced, thereby improving the detection accuracy of the laser beam orientation.

In some examples, the target 21 may include a reference layer 213 disposed behind the intermediate layer 212. In some examples, the reference layer 213 may be provided with a probe position sensing unit 2131, and the probe position sensing unit 2131 may be configured to receive the laser beam passing through the through hole 2122.

In some examples, the probe position sensing unit 2131 can have a photosurface, and in some examples, the photosurface of the probe position sensing unit 2131 can be parallel to the plane of the incision Sc. In some examples, the photosurface of the probe position sensing unit 2131 may be parallel to the plane of incidence Si. In some examples, the photosurface of the probe position sensing unit 2131 may be perpendicular to the optical axis Ao of the target 21. In this case, since the light sensing surface is perpendicular to the two axes of the target coordinate system, the posture of the target 21 can be represented by the position of the flare acquired by the probe position sensing unit 2131, and the calculation can be simplified. However, the present disclosure is not limited thereto, and the photosurface of the probe position sensing unit 2131 may be non-parallel to the slit plane Sc.

In some examples, after the probe position sensing unit 2131 receives the laser beam passing through the through hole 2122, the probe position sensing unit 2131 is configured to detect a moving distance of the laser beam passing through the through hole 2122 with respect to a preset zero point through the photosurface and obtain sensing information, whereby it can be determined whether the target 21 is aligned with the laser emitting unit based on a spot formed by the laser beam on the photosurface of the probe position sensing unit 2131.

In some examples, the probe position sensing unit 2131 can record the position of the light spot on the photosurface of the probe position sensing unit 2131. In this case, the posture of the target 21 and the posture adjustment method of the target 21 can be calculated based on the position of the flare on the light-sensitive surface of the probe position sensing unit 2131. Compared with the calculation mode that a plurality of light emitting devices are required to be arranged on the six-dimensional probe 2 in the prior art, the positions of the plurality of light emitting devices in space are acquired by using the gesture camera and the zoom optical lens arranged on the laser tracker 1, and the gesture of the target 21 is calculated based on the positions of the plurality of light emitting devices in space, compared with the calculation mode that the gesture of the target 21 is calculated by using the probe position sensing unit 2131, the gesture adjustment mode that the plurality of light emitting devices are not required to be arranged on the six-dimensional probe 2, and the gesture camera and the zoom optical lens are not required to be arranged on the laser tracker 1, so that the manufacturing cost and the design cost can be effectively reduced, and the situation that the gesture of the target 21 is lower in measurement precision due to the fact that the gesture camera and the zoom optical lens are difficult to focus due to the too far distance of the target 21 is avoided. Compared with the prior art, the method and the device for directly calculating the posture of the six-dimensional probe 2 (target) by using the spot position information of the position sensing unit arranged on the six-dimensional probe 2, the calculated posture of the six-dimensional probe 2 (target) is easily influenced by the nonlinearity and drift errors of the position sensing unit, and the measurement accuracy of the target is unstable. The probe position sensing unit 2131 is used to obtain the posture of the target 21 and the posture adjustment mode of the target 21, and the target 21 is aligned to the laser emission unit, so that the light spot formed by the laser beam is continuously located at a fixed point or a servo zero point (i.e. a preset zero point) in the probe position sensing unit 2131, and then the probe angle measuring unit, the probe gravity alignment unit 26 and other components are matched to calculate the posture of the six-dimensional probe 2 (target) (described later), so that the influence of the nonlinearity and drift error of the position sensing unit on the precision of the posture of the six-dimensional probe 2 (target) can be effectively reduced, and the precision of the posture measurement precision of the target is improved.

In some examples, the pose adjustment of the target 21 may be determined based on the relative position between the spot and a preset zero point of the probe position sensing unit 2131, which may be located at the position of the spot when the target 21 is aligned with the laser emitting unit.

In some examples, the probe position sensing unit 2131 may obtain the position of the light spot in real time. In other words, after the probe position sensing unit 2131 forms a light spot, the probe position sensing unit 2131 can continuously acquire the position of the light spot. In this case, the posture of the target 21 can be continuously determined, and thus the posture adjustment manner of the target 21 can be determined in real time, and the probe tracking control unit is controlled based on the posture adjustment manner of the target 21 so that the target 21 is aligned with the laser emitting unit in real time. In some examples, the probe position sensing unit 2131 may be a position sensor (Position Sensitive Detector, PSD) or CCD (charge coupled device) camera.

In some examples, when the hollow cube-corner prism does not receive the laser beam, the laser tracker 1 may be considered misaligned with the target 21; the hollow pyramid prism receives the laser beam and can consider that the laser tracker 1 is aligned with the target 21; when the hollow pyramid prism receives the laser beam, and at least a portion of the laser beam passes through the through hole 2122 and forms a spot at the probe position sensing unit 2131, and the spot formed by at least a portion of the laser beam at the probe position sensing unit 2131 is not at a preset zero point, it can be considered that the laser beam is not parallel to the optical axis Ao of the target 21, and the target 21 is not aligned with the laser tracker 1; when the hollow pyramid prism receives the laser beam and at least a portion of the laser beam passes through the through hole 2122 and forms a spot at the probe position sensing unit 2131 and at least a portion of the laser beam forms a spot at the probe position sensing unit 2131 at a preset zero point, the laser beam can be considered to be parallel to the optical axis Ao of the target 21 and the target 21 is aligned with the laser tracker 1. In this case, it is possible to determine which stage the six-dimensional posture detection device is in based on the relationship between the laser beam and the six-dimensional probe 2.

In some examples, the surface of the target 21 may not be provided with a light emitting device for acquiring the pose of the target 21. In this case, the manufacturing cost and the design cost of the target 21 can be effectively reduced, and at the same time, the attitude camera and the zoom optical lens for receiving the light beam of the light emitting device of the target 21 can be omitted from the laser tracker 1, further reducing the manufacturing cost and the design cost of the laser tracker 1.

In some examples, referring to fig. 2, the six-dimensional probe 2 may include a probe tracking control unit, which may be configured to control the pose of the target 21 based on the sensing information acquired by the probe position sensing unit 2131 to align the target 21 with the laser emitting unit. In this case, the target 21 can be driven by the probe tracking control unit to align the target 21 with the laser emitting unit.

In some examples, the probe tracking control unit may include a first rotation mechanism 231 (see fig. 2) that controls rotation of the target 21 in the first direction D1. In this case, the rotation of the target 21 in the first direction D1 can be controlled by the first rotation mechanism 231 to track the laser tracker 1 in the first direction D1.

In some examples, the probe tracking control unit may include a second rotation mechanism 232 (see fig. 4) that controls rotation of the target 21 in the second direction D2. In this case, the target 21 can be controlled to rotate in the second direction D2 by the second rotation mechanism 232 to track the laser tracker 1 in the second direction D2.

In some examples, referring to fig. 3 and 4, rotation of the target 21 in the first direction D1 may refer to rotation of the target 21 in a first plane S1, the first plane S1 being perpendicular to the first rotation axis 2311, where the target 21 may rotate about the first rotation axis 2311.

In some examples, when the six-dimensional probe 2 is mounted on the target, with the surface of the target on which the fixing base 22 is mounted being the mounting surface, the first plane S1 may be parallel to the mounting surface. In other words, the first plane S1 is associated with a surface on the target for mounting the fixing base 22 as a mounting surface, and when the posture of the target is changed, the first plane S1 may also be changed, and when the target 21 is rotated in the first direction D1, the first rotation axis 2311 may be perpendicular to the mounting surface. However, the present disclosure is not limited thereto, and in some examples, when the first rotation mechanism 231 drives the target 21 to rotate, the target 21 may also rotate in any plane, that is, when the target 21 rotates in the first direction D1, the first rotation shaft 2311 of the first rotation mechanism 231 may be oriented in any direction.

In some examples, referring to fig. 3 and 4, rotation of the target 21 in the second direction D2 may mean that the target 21 may rotate within a second plane S2, the second plane S2 is not coincident with and parallel to the first plane S1, and the second plane S2 is perpendicular to the second rotation axis 2321, and the target 21 may rotate about the second rotation axis 2321.

In some examples, the second plane S2 may be a plane perpendicular to the kerf plane Sc (or the photosurface of the probe position sensing unit 2131), in other words, the second rotation axis 2321 may be parallel to the kerf plane Sc (or the photosurface of the probe position sensing unit 2131). In some examples, when the six-dimensional probe 2 is mounted on the target, with the surface of the target on which the fixing base 22 is mounted being the mounting surface, the second plane S2 may be perpendicular to the mounting surface. In other words, the second plane S2 is associated with a surface on the target for mounting the fixing base 22 as a mounting surface, and when the posture of the target is changed, the second plane S2 may also be changed, and when the target 21 rotates in the second direction D2, the second rotation axis 2321 may be parallel to the mounting surface. However, the disclosure is not limited thereto, and in some examples, when the second rotation mechanism 232 drives the target 21 to rotate, the target 21 may also rotate in any plane, that is, when the target 21 rotates in the second direction D2, the second rotation axis 2321 of the second rotation mechanism 232 may be oriented in any direction.

In some examples, the first rotation axis 2311 may be perpendicular to the second rotation axis 2321. In other words, the first plane S1 may be perpendicular to the second plane S2. In this case, the posture adjustment method of the target 21 can be easily decomposed into the rotation in the first direction D1 and the rotation in the second direction D2, so that the target 21 can be easily controlled to be directed in any direction, that is, the direction of the optical axis Ao of the target 21 by the first rotation mechanism 231 and the second rotation mechanism 232.

In some examples, the axis A1 of the first rotation shaft 2311 may intersect the axis A2 of the second rotation shaft 2321, and an intersection of the axis A1 of the first rotation shaft 2311 and the axis A2 of the second rotation shaft 2321 may be taken as an origin of the target coordinate system. In this case, the calculation can be simplified, the calculation speed can be increased, the occurrence of calculation errors can be reduced, and the accuracy of calculation can be improved.

In some examples, the target coordinate system may be a coordinate system having an intersection point of the axis A1 of the first rotation shaft 2311 and the axis A2 of the second rotation shaft 2321 as an origin, a direction of the axis A1 of the first rotation shaft 2311 as a Z-axis direction, a direction of the axis A2 of the second rotation shaft 2321 as a Y-axis direction, and a direction perpendicular to the axis A1 of the first rotation shaft 2311 and the axis A2 of the second rotation shaft 2321 as an X-axis direction.

In some examples, the axis A1 of the first rotation shaft 2311 may intersect the axis A2 of the second rotation shaft 2321, and an intersection of the axis A1 of the first rotation shaft 2311 and the axis A2 of the second rotation shaft 2321 may be disposed at the vertex V of the mirror 2111 having the slit. In other words, the vertex V of the mirror 2111 may be located at the intersection of the axis A1 of the first rotation shaft 2311 and the axis A2 of the second rotation shaft 2321. In this case, the calculation can be simplified, the calculation speed can be increased, and the calculation accuracy can be improved.

In some examples, referring to fig. 4, the first rotation mechanism 231 may include a first rotation shaft 2311, a first rotation chassis 2313, and at least one support arm 2312 provided to the first rotation chassis 2313, and the target 21 may be provided to the support arm 2312. In some examples, the first rotation mechanism 231 may include two support arms 2312, and the target 21 may be disposed between the two support arms 2312.

In some examples, the first rotation mechanism 231 may be provided to the fixed base 22, and the first rotation mechanism 231 may include a first rotation shaft 2311, a first bearing 2314 matched with the first rotation shaft 2311, a support arm 2312 coupled with the first rotation shaft 2311, and a first driving motor 2315 driving the first rotation shaft 2311 to rotate. In this case, the first rotation shaft 2311 can be driven to rotate by the first driving motor 2315, and the support arm 2312 can be driven to rotate about the first rotation shaft 2311, and the target 21 can be driven to rotate about the first rotation shaft 2311 by the support arm 2312.

In some examples, the first rotation mechanism 231 may include a first angle encoder and a first drive card that controls the first drive motor 2315.

In some examples, the first rotation mechanism 231 may control rotation of the target 21 in the first direction D1. In some examples, the first rotation chassis 2313 may be provided to the first rotation shaft 2311, and the first rotation shaft 2311 may be provided to the fixed base 22 through a first bearing 2314. In this case, the first rotation mechanism 231 can rotate by driving the first rotation shaft 2311 and driving the first rotation chassis 2313 provided on the first rotation shaft 2311 to rotate in the first direction D1, and thus can drive the target 21 provided on the support arm 2312 to rotate in the first direction D1.

In some examples, the second rotation mechanism 232 may be provided to the support arm 2312 of the first rotation mechanism 231 and capable of driving the second rotation shaft 2321 to rotate in the second direction D2. In some examples, the second rotation shaft 2321 may be linked with the target 21. In this case, the target 21 can be driven to rotate in the second direction D2 by the second rotation mechanism 232. In some examples, the second rotation mechanism 232 may include a second rotation shaft 2321 that connects the target 21 and positions the target 21 to the support arm 2312, a second bearing 2322 that mates with the second rotation shaft 2321, a second angle encoder, a second drive motor 2323 that drives the second rotation shaft 2321 to rotate, and a second drive card that controls the second drive motor 2323. In this case, the second rotation shaft 2321 can be provided to the support arm 2312 by the second bearing 2322, and the support arm 2312 can further drive the second rotation shaft 2321 and the target 21 provided to the second rotation shaft to rotate around the first rotation shaft 2311, and at the same time, the second rotation shaft 2321 can be driven to rotate by the second driving motor 2323, and further the target 21 can be driven to rotate around the second rotation shaft 2321, so that the second rotation shaft 2321 can drive the target 21 to rotate along the second direction D2.

In some examples, the first and second rotation shafts 2311 and 2321 may be precision shafts, and the first and second bearings 2314 and 2322 that mate with the first and second rotation shafts 2311 and 2321 may be precision bearings.

In some examples, the probe tracking control unit may be configured to control the pose of the target 21 based on the sensory information acquired by the probe position sensing unit 2131 to align the target 21 with the laser emitting unit. Specifically, in the probe position sensing unit 2131, if the light spot is far from the preset zero point, it is considered that the target 21 is not aligned with the laser emitting unit, and the posture adjustment method of the target 21 can be calculated based on the relative position between the light spot and the preset zero point. In this case, the probe tracking control unit can be caused to control the target 21 to reversely track the laser emitting unit based on the calculation result, and the relative position between the light spot and the preset zero point may refer to the position of the light spot with respect to the preset zero point.

In some examples, the probe tracking control unit may be comprised of a first rotation mechanism 231 and a second rotation mechanism 232. In this case, the rotation of the target 21 in two directions can be controlled, the probe tracking control unit constituted by the first rotation mechanism 231 and the second rotation mechanism 232 can reduce the manufacturing cost and the design cost, and at the same time, in the case where the probe tracking control unit is constituted by the first direction D1 rotation and the second rotation mechanism 232, the alignment of the target 21 to the laser emitting unit can be controlled, and the attitude of the target 21 can be obtained based on the calculation.

In some examples, referring to fig. 4, the six-dimensional probe 2 may include a probe angle measurement unit, which may be configured to measure the rotation angle of the target 21 under the control of the probe tracking control unit. In this case, the rotation angle of the target 21 can be obtained by the probe angle measurement unit, whereby the positional relationship between the posture of the target 21 and the posture of the six-dimensional probe 2 can be determined based on the rotation angle of the target 21, and thus the rotation angle of the target 21 with respect to the six-dimensional probe 2 can be obtained, and thus the spatial posture of the target can be calculated based on the rotation angle of the six-dimensional probe 2. In the process of rotating the target 21 by the probe tracking control unit, that is, the process of controlling the target 21 to rotate relative to the fixed base 22, the posture of the six-dimensional probe 2 may refer to the posture of the fixed base 22 in the six-dimensional probe 2, and since the fixed base 22 is mounted on the target, the movement pattern of the fixed base 22 is synchronized with the movement pattern of the target, and thus the posture of the six-dimensional probe 2 may also refer to the posture of the target. Meanwhile, since the target 21 is continuously aligned with the laser emitting unit under the control of the probe tracking control unit, the posture of the target 21 may be changed in synchronization with the direction vector of the laser beam. In other words, the rotation angle of the target 21 with respect to the six-dimensional probe 2 is acquired, that is, the change in the direction vector of the laser beam with respect to the target is acquired.

In some examples, calculating the spatial pose of the target based on the rotation angle of the six-dimensional probe 2 may refer to determining a direction vector of the laser beam in the target coordinate system based on the rotation angle of the target 21, then determining a direction vector of the laser beam in the laser tracker device coordinate system based on the rotation angle of the laser emitting unit, and calculating the yaw angle of the six-dimensional probe 2 (target) using the direction vectors of the laser beam in different coordinate systems (e.g., the laser tracker device coordinate system, the target coordinate system, and the target coordinate system) and the transformation relationship between the different coordinate systems.

In some examples, referring to fig. 4, the probe angle measurement unit may include a first probe angle measurement unit 24 configured to measure a rotation angle of the target 21 rotating in the first direction D1 and a second probe angle measurement unit 25 configured to measure a rotation angle of the target 21 rotating in the second direction D2. In this case, the rotation angle of the target 21 in the first direction D1 and the rotation angle of the target in the second direction D2 can be obtained, and the direction vector of the laser beam in the target coordinate system can be calculated based on the rotation angle of the target 21 in the first direction D1 and the rotation angle of the target in the second direction D2.

In some examples, the probe angle measurement unit includes a grating disk and a reading head disposed on a rotating shaft. For example, the first probe angle measurement unit 24 may include a first probe grating disk 241 provided to the first rotation shaft 2311 and a first probe reading head 242 obtaining a rotation angle of the target 21 rotated in the first direction D1 based on the first probe grating disk 241. The second probe angle measurement unit 25 may include a second probe grating disk 251 provided to the second rotation shaft 2321 and a second probe reading head 252 obtaining a rotation angle of the target 21 rotated in the second direction D2 based on the second probe grating disk 251. In this case, the rotation angle of the first rotation axis 2311 or the second rotation axis 2321 can be measured by the probe angle measurement unit to calculate the direction vector of the laser beam in the target coordinate system. The present disclosure is not limited thereto and the probe angle measurement unit may be an instrument based on other measurement principles and capable of measuring the rotation angle of the target 21.

In some examples, referring to fig. 4 and 7, the six-dimensional probe 2 may include a probe gravity alignment unit 26. In some examples, the probe gravity alignment unit 26 may be configured to acquire a pose of the target, in some examples, the probe gravity alignment unit 26 may be used to acquire at least one euler angle of the target. In some examples, the probe gravity alignment unit 26 may be used to acquire pitch and roll angles of the target.

In some examples, the probe gravity alignment unit 26 may be configured to correlate the direction information acquired based on the probe angle measurement unit to a target coordinate system (e.g., align coordinate values of the laser beam direction in the target coordinate system to the target coordinate system). The direction information acquired by the probe angle measurement unit may include a rotation angle at which the target 21 rotates in the first direction D1 and a rotation angle at which it rotates in the second direction D2.

In some examples, referring to fig. 4, 6, and 7, a probe gravity alignment unit 26 may be provided to the stationary base 22. In this case, since the stationary base 22 is mounted to the target, kept relatively stationary with respect to the target, the probe gravity alignment unit 26 can be rotated without rotation of the target 21, can be kept stationary with respect to the target, and thus can measure the inclination angle of the target. In addition, compared with the scheme of arranging the probe gravity alignment unit 26 on the target 21, that is, the scheme that the probe gravity alignment unit 26 is driven by the first rotation mechanism 231 or the second rotation mechanism 232 to rotate, the dynamic response requirement of the probe gravity alignment unit 26 can be reduced, so that the measurement accuracy of the probe gravity alignment unit 26 can be improved, and meanwhile, the calculation process can be simplified.

In some examples, the probe gravity alignment unit 26 may be a target tilt angle by measuring the tilt angle of the stationary base 22 relative to the horizontal. In other words, the probe gravity alignment unit 26 may be configured to acquire a target tilt angle of the six-dimensional probe 2, which may be configured to calculate a transformation relationship between the target coordinate system and the target coordinate system. In this case, the direction vector of the laser beam in the laser tracker device coordinate system can be correlated with the direction vector of the laser beam in the target coordinate system. Meanwhile, since most parts of the six-dimensional probe 2 are kept relatively stationary with respect to the stationary base 22 except for the rotatable target 21, the inclination angle of the stationary base 22 with respect to the horizontal plane may also refer to the inclination angle of the six-dimensional probe 2 with respect to the horizontal plane, and since the stationary base 22 is mounted to the target, the inclination angle of the stationary base 22 with respect to the horizontal plane may also be the inclination angle of the target with respect to the horizontal plane, for example, the pitch angle and roll angle of the target with respect to the horizontal plane may be the pitch angle and roll angle of the target. Meanwhile, since the transformation relationship between the target coordinate system and the target coordinate system can be obtained by using the euler angles (including pitch angle and roll angle and yaw angle) of the target, the yaw angle of the target can be calculated under the condition that the direction vector of the laser beam in the laser tracker device coordinate system, the direction vector of the laser beam in the target coordinate system, the pitch angle of the target and the roll angle of the target are known.

In some examples, referring to fig. 9, probe gravity alignment unit 26 may include two single axis accelerometers with their axes of sensitivity orthogonal. However, the present disclosure is not limited thereto and in some examples, the probe gravity alignment unit 26 may also include a tri-axial accelerometer. In some examples, the probe gravity alignment unit 26 may also include a dual axis accelerometer. In some examples, probe gravity alignment unit 26 may also include two single axis inclinometers or one dual axis inclinometer (inclinometer). In some examples, the probe gravity alignment unit 26 may also include a level. In some examples, the probe gravity alignment unit 26 may include any device that enables the angle of inclination of the stationary base 22 relative to the horizontal. In this case, a transformation relationship between the target coordinate system and the target coordinate system can be calculated by obtaining the two target inclination angles.

In some examples, the accelerometer in the probe gravity alignment unit 26 may be a closed loop liquid float pendulum, flexible pendulum, vibrating wire or pendulum integrating gyroscope, etc., and the tilt sensor may be a solid pendulum, liquid pendulum or gas pendulum, etc. In some examples, the accelerometer may also be a MEMS accelerometer, and in some examples, the accelerometer may also be a capacitive pendulum sensor.

In some examples, taking the probe gravity alignment unit 26 as an example that includes two single-axis inclinometers, and the sensitive axes of the two single-axis inclinometers are orthogonal, the probe gravity alignment unit 26 may include a first inclinometer 26a and a second inclinometer 26b (see fig. 9), where the sensitive axes of the first inclinometer 26a and the second inclinometer 26b may be in the same plane, such that a plane formed by the sensitive axes of the first inclinometer 26a and the second inclinometer 26b is a sensitive plane, the sensitive plane may be perpendicular to the first rotation axis 2311, the sensitive plane may be parallel to the second rotation axis 2311, the sensitive axis of the first inclinometer 26a may be parallel to the second rotation axis 2321, and the sensitive axis of the second inclinometer 26b may be perpendicular to the second rotation axis 2321. In other words, the probe gravity alignment unit 26 may include a first inclinometer 26a and a second inclinometer 26b, the installation direction of the first inclinometer 26a may be perpendicular to the extension direction of the rotation axis of the first rotation mechanism 231, the installation direction of the second inclinometer 26b may be parallel to the extension direction of the rotation axis of the second rotation mechanism 232, and the installation direction of the first inclinometer 26a may be perpendicular to the installation direction of the second inclinometer 26 b. In this case, since the sensitive axis of the probe gravity alignment unit 26 is matched with the rotation axis of the probe tracking control unit, it is possible to simplify the transformation formulas of the target coordinate system and the target coordinate system, to improve the calculation speed, and to improve the accuracy of measurement. Meanwhile, it is possible to let the target inclination angle measured by the first inclinometer 26a be the pitch angle of the fixed base 22 (target), and the target inclination angle measured by the second inclinometer 26b be the roll angle of the fixed base 22 (target). However, the disclosure is not limited thereto, and in other examples, the sensitive axes of the two single-axis inclinometers may not be parallel or perpendicular to the second rotation axis 2321.

In some examples, the target tilt angle may be broken down into a target tilt angle a and a second tilt angle b. In some examples, the target tilt angle a may be acquired by a first inclinometer 26a and the target tilt angle b may be acquired by a second inclinometer 26 b. In some examples, the target tilt angle a and the target tilt angle b may also be obtained by a dual axis inclinometer. In some examples, target tilt angle a and target tilt angle b may also be obtained by a monolithically integrated triaxial inclinometer, wherein the two sensitive axes of the triaxial inclinometer are parallel and perpendicular to the second rotational axis 2321, respectively.

In some examples, the probe gravity alignment unit 26 may acquire the target tilt angle in real-time. In other words, the probe gravity alignment unit 26 may continuously measure the target tilt angle without interruption when calculating the six-dimensional coordinates of the target using the six-dimensional posture detection device. In this case, the target tilt angle can be acquired in real time, and the euler angle of the six-dimensional probe 2 can be acquired using the target tilt angle in real time.

In some examples, the six-dimensional probe 2 may further include a gyroscope disposed on the stationary base 22, which may be configured to enhance the accuracy of the target tilt angle acquired by the probe gravity alignment unit 26 for the target in dynamic conditions. Since acceleration other than gravity is introduced into the probe gravity alignment unit 26 when the fixed base 22 (target) moves, accuracy of the target inclination angle is lowered, and accuracy of measurement of the target inclination angle can be improved by using the gyroscope.

In some examples, six-dimensional probe 2 may also include two gyroscopes mounted orthogonal to each other, by introducing two orthogonal gyroscopes to measure the angular velocity of the direction in which the sensitive axis of first inclinometer 26a is located and the angular velocity of the direction in which the sensitive axis of second inclinometer 26b is located, respectively. In this case, since the gyroscope has higher angular accuracy in a short time, it is suitable for measuring angular velocity under motion, and the data measured by the probe gravity alignment unit 26 and the gyroscope measurement data are fused by a filtering algorithm such as Kalman, the data measured by the probe gravity alignment unit 26 and the gyroscope measurement data can be complemented, and thus the dynamic measurement accuracy of the target inclination angle can be improved.

In some examples, six-dimensional probe 2 may not include a gyroscope, thereby enabling manufacturing costs to be reduced. In some examples, a gyroscope may be provided as an optional component of the six-dimensional probe 2, and may be detachably disposed on the fixed base 22. In this case, it can be confirmed whether or not the gyroscope needs to be equipped or installed based on the use situation.

In some examples, referring to fig. 1, the six-dimensional gesture detection apparatus may include a data analyzer 3. In some examples, the data analyzer 3 may be built-in with analysis software.

The present disclosure also relates to a gesture detection method based on back tracking, which can realize back tracking of the six-dimensional probe 2 and can obtain the euler angle of the target. In some examples, the back tracking based gesture detection method may also be referred to as a multi-dimensional measurement method, a method of determining the orientation of a target, or a target measurement method. In some examples, the methods contemplated by the present disclosure can be implemented by a six-dimensional probe contemplated by the present disclosure. The present disclosure is not limited thereto and the methods related to the present disclosure may also be applied to other apparatuses capable of implementing these methods.

In some examples, the target 21 is aligned to a laser emitting unit (step S001); the euler angle of the target is obtained (step S003). In this case, since the target 21 can be aligned with the laser emitting unit to achieve the back tracking, and the euler angle of the target can be calculated based on the rotation angle of the target 21.

In some examples, in step S001, the target 21 may be aligned with the laser emitting unit. In some examples, the targets 21 may be rotated in two directions in the six-dimensional probe 2, respectively, to align the targets 21 with the laser emitting units. In some examples, the two directions may be the first direction D1 and the second direction D2 described above.

In some examples, the probe position sensing unit 2131 provided to the target 21 may be used to receive the laser beam passing through the preset position, and the rotation of the target 21 in the first direction D1 and the rotation in the second direction D2 may be controlled to align the target 21 with the laser emitting unit based on the posture adjustment manner of the target 21 calculated by the laser beam received by the target 21 at the spot of the probe position sensing unit 2131. In this case, since the laser emitting unit is aligned with the target 21 when the laser beam passes through the preset position, the target 21 is aligned with the laser emitting unit, the incident plane Si of the target 21 can be perpendicular to the laser beam, and thus the direction vector of the laser beam in the target coordinate system can be represented by the rotation angle of the target 21.

In some examples, in step S003, the euler angle of the target may be obtained. In some examples, the roll angle and pitch angle of the target are obtained using a probe gravity alignment unit 26 provided to the six-dimensional probe 2. In some examples, the roll angle and pitch angle of the target are obtained using an inclinometer or accelerometer provided to the six-dimensional probe 2. In this case, a partial euler angle of the target can be obtained conveniently, and the transformation relationship between the target coordinate system and the target coordinate system can be represented by the partial euler angle in the subsequent process, so that other euler angles can be calculated.

In some examples, the yaw angle of the target may be calculated based on the rotation angle of the target 21 and the roll angle and pitch angle of the target, including: establishing a laser tracker equipment coordinate system, a target coordinate system and a target coordinate system, acquiring a transformation relation between the laser tracker equipment coordinate system and the target coordinate system, acquiring a transformation relation between the target coordinate system and the target coordinate system, acquiring a direction vector of a laser beam in the laser tracker equipment coordinate system as an equipment laser beam vector, acquiring a direction vector of the laser beam in the target coordinate system as a target laser beam vector, establishing an equation and calculating a yaw angle of the target. In this case, the yaw angle of the six-dimensional probe 2 (target) can be calculated using the direction vectors of the laser beam in the different coordinate systems and the transformation relationship between the different coordinate systems.

In some examples, the inclination angle of the laser emitting unit with respect to the horizontal plane may be acquired by using a tracking head gravity alignment unit provided to the laser tracker 1 and further acquiring a transformation relationship between the laser tracker device coordinate system and the target coordinate system; acquiring an inclination angle of the six-dimensional probe 2 relative to the horizontal plane as a target inclination angle by using a probe gravity alignment unit 26 arranged on the six-dimensional probe 2, and acquiring a transformation relationship between a target coordinate system and the target coordinate system based on the second inclination angle; the device laser beam vector is acquired based on the rotation angle of the laser emitting unit. The transformation relation between the laser tracker equipment coordinate system and the target coordinate system and the equipment laser beam vector acquire a target laser beam vector; the target laser beam vector is acquired based on the rotation angle of the target 21. In this case, different coordinate systems can be established based on different reference systems, and the transformation relationship of the different coordinate systems and the target coordinate system can be obtained, and further, the direction vectors of the laser beam in the different coordinate systems can be correlated and a formula can be obtained, and further, the yaw angle of the target can be calculated based on the formula.

In some examples, the target laser beam vector may be expressed as:

wherein,,represents the target laser beam vector, OT represents the target coordinate system, ">The direction vector of the laser beam is shown, α is the angle by which the target 21 rotates in the second direction D2 (i.e., the angle by which the second rotation axis 2321 rotates when the target 21 rotates), and β is the angle by which the target 21 rotates in the first direction D1 (i.e., the angle by which the first rotation axis 2311 rotates when the target 21 rotates). Alpha may be obtained by the second probe angle measurement unit 25 and beta may be obtained by the first probe angle measurement unit 24.

In some examples, the target laser beam vector and the target laser beam vector may satisfy:

wherein,,represents the target laser beam vector, OG represents the target coordinate system,>and representing the transformation relation between the target coordinate system and the target coordinate system.

In some examples, the transformation relationship of the target coordinate system and the target coordinate system may satisfy:

wherein,,representing the transformation relationship between the target coordinate system and the target coordinate system, ω, δ and +.>Respectively representing roll angle, yaw angle and pitch angle of the six-dimensional probe 2 (or object), rx (ω) represents a rotation matrix related to roll angle, +.>Representing the rotation matrix associated with pitch angle and Rz (delta) representing the rotation matrix associated with yaw angle.

In some examples, the target laser beam vector and the device laser beam vector may satisfy:

wherein,,representing the device laser beam vector, O _L Representing the laser tracker device coordinate system, +.>Indicating laser tracker deviceThe transformation relation between the coordinate system and the target coordinate system is prepared. />Can be obtained by calculating the rotation angle of the laser tracker 1 obtained by the tracking head angle measuring unit from the mechanical zero point of the laser tracker 1 to the center of the pyramid. />Can be obtained by calculating the inclination angle of the laser emitting unit relative to the horizontal plane.

In some examples, the angular velocity of the target may be measured and the target tilt angle corrected using the angular velocity of the target and a Kalman algorithm as the target moves. In some examples, as above, the angular velocity of the target may be measured using a gyroscope provided to the six-dimensional probe 2. Under the condition, as the gyroscope has higher angle measurement precision in a short time, the gyroscope is suitable for measuring the angular speed under the motion, and the target inclination angle can be corrected through a Kalman filtering algorithm and the like, so that the dynamic measurement precision of the target inclination angle can be improved.

While the disclosure has been described in detail in connection with the drawings and examples, it is to be understood that the foregoing description is not intended to limit the disclosure in any way. Modifications and variations of the present disclosure may be made as desired by those skilled in the art without departing from the true spirit and scope of the disclosure, and such modifications and variations fall within the scope of the disclosure.

Claims

1. A six-dimensional probe based on back tracking, which is a six-dimensional probe for being mounted on a target and cooperating with a laser tracker to obtain the position and posture of the target, comprising: a fixed base configured to mount the six-dimensional probe to the target, the target having a through hole and configured to reflect laser light or a scattered light beam emitted from the laser tracker to the laser tracker, a target, a probe position sensing unit configured to receive the laser light passing through the through hole and obtain sensing information, a probe tracking control unit configured to control a posture of the target based on the sensing information to align the target to the laser tracker, the alignment being such that at least a part of a laser beam emitted from the laser tracker passes through the through hole and is parallel to an optical axis of the target, the probe tracking control unit including a first rotation mechanism that controls rotation of the target in a first direction and a second rotation mechanism that controls rotation of the target in a second direction, the probe gravity alignment unit disposed to the fixed base and configured to measure the posture of the target; the six-dimensional probe comprises a probe angle measuring unit, the probe angle measuring unit comprises a first probe angle measuring unit and a second probe angle measuring unit, the first probe angle measuring unit is used for measuring the rotation angle of the target rotating along the first direction, the second probe angle measuring unit is used for measuring the rotation angle of the target rotating along the second direction, and the probe angle measuring unit and the probe gravity alignment unit are matched to calculate the posture of the six-dimensional probe.

2. The six-dimensional probe based on back tracking according to claim 1, wherein,

the probe gravity alignment unit comprises a first inclinometer and a second inclinometer,

the installation direction of the first inclinometer is perpendicular to the extension direction of the rotating shaft of the first rotating mechanism,

the installation direction of the second inclinometer is parallel to the extension direction of the rotating shaft of the second rotating mechanism,

the installation direction of the first inclinometer is perpendicular to the installation direction of the second inclinometer.

3. The six-dimensional probe based on back tracking according to claim 1, wherein,

the first rotating mechanism is arranged on the fixed base and comprises a first rotating shaft, a first bearing matched with the first rotating shaft, a supporting arm linked with the first rotating shaft and a first driving motor for driving the first rotating shaft to rotate.

4. A six-dimensional probe based on back tracking according to claim 3,

the second rotating mechanism is arranged on the supporting arm and comprises a second rotating shaft, a second bearing matched with the second rotating shaft and a second driving motor for driving the second rotating shaft to rotate, and the target is arranged on the second rotating shaft and is linked with the second rotating shaft.

5. A six-dimensional probe based on back tracking according to claim 3,

the target includes a reference layer configured to mount the probe position sensing unit, a prism layer provided with a hollow pyramid prism, and an intermediate layer between the reference layer and the prism layer and having the through hole.

6. The six-dimensional probe based on back tracking according to claim 5,

and a filter positioned between the through hole and the probe position sensing unit is arranged on the reference layer.

7. The six-dimensional probe based on back tracking according to claim 5,

the probe position sensing unit is arranged on the reference layer, the probe position sensing unit comprises a light sensitive surface, the light sensitive surface is perpendicular to the axis of the hollow pyramid prism, and the probe position sensing unit is configured to detect the moving distance of the laser passing through the through hole relative to a preset zero point through the light sensitive surface and obtain sensing information.

8. The six-dimensional back-tracking based probe of claim 7,

the vertex of the hollow pyramid prism is positioned at the intersection point of the axis of the first rotating shaft and the axis of the second rotating shaft.

9. The six-dimensional back-tracking based probe of claim 8,

the axis of the first rotating shaft is perpendicular to the sensitive plane of the probe gravity alignment unit, and the axis of the second rotating shaft is parallel to the sensitive plane.