Laser tracker with automatic positioning function

Abstract

A laser tracker with an automatic positioning function disclosed by the present invention comprises a laser tracker body, the laser tracker body comprises a base, a horizontal rotation structure, a pitching structure and a laser probe structure, the horizontal rotation structure is installed on the base, and the pitching structure is installed on the base. The pitching structure is installed on the upper portion of the horizontal rotating structure through a pitching frame, the laser measuring head assembly is fixedly installed on an installation base of an extension arm of the pitching structure, and the laser measuring head assembly further comprises an automatic positioning structure. The automatic positioning structure comprises a wide area search sensing unit, a precision deviation sensing unit and a control system. By means of the mode, the laser tracker with the automatic positioning function is provided with an automatic positioning structure and can automatically recognize a target and autonomously complete initial positioning and relocking, and therefore the measurement automation degree and efficiency are improved; the problems that traditional equipment depends on manual operation, the positioning efficiency is low, and the automation degree is insufficient are solved.

Description

Technical Field

[0001] This invention belongs to the field of measurement technology, and specifically relates to a laser tracker with automatic positioning function. Background Technology

[0002] Traditional laser trackers are widely used in industrial measurement, aerospace, and large equipment installation, mainly for high-precision spatial coordinate measurement.

[0003] Existing laser trackers typically include a laser emitting unit, an angle measuring unit, a distance measuring unit, and a tracking control unit. During operation, manual control of the instrument's rotation and pitch via a handle or software commands is required to align the laser beam with the target reflector before measurement. This operation method relies on manual operation for initial positioning, demanding a high level of technical proficiency from the operator. Especially in complex environments, positioning the reflector is time-consuming. When the target reflector moves or is temporarily lost, manual re-searching and re-locking of the target is required, making the measurement process prone to interruption and inefficient. Summary of the Invention

[0004] The main technical problem solved by this invention is to provide a laser tracker with automatic positioning function, which can improve the degree of automation and efficiency of measurement.

[0005] To solve the above-mentioned technical problems, one technical solution adopted by the present invention is: to provide a laser tracker with automatic positioning function, including a laser tracker body, the laser tracker body including a base, a horizontal rotation structure, a pitch structure and a laser probe structure, the horizontal rotation structure being mounted on the base, the pitch structure being mounted on the upper part of the horizontal rotation structure through a pitch frame, the laser probe assembly being fixedly mounted on the mounting seat of the extension arm of the pitch structure, and also including an automatic positioning structure; The automatic positioning structure includes a wide-area search sensing unit, a precision deviation sensing unit, and a control system. The wide-area search sensing unit is fixed on the top of a support bracket perpendicular to the surface of the pitch frame. The support bracket consists of two vertical plates and a top plate. The two vertical plates are arranged on both sides of the pitch structure, and the top plate is arranged on top of the two vertical plates. The precision deviation sensing unit is mounted on the mounting base, adjacent to the laser probe structure; The control system is installed in the control cabinet next to the laser tracker body, and the control system has a built-in motion control module and a signal processing module.

[0006] In a preferred embodiment of the present invention, the horizontal rotation structure includes a horizontal rotation shaft and a first drive motor that drives the horizontal rotation shaft to rotate about a vertical axis, and the horizontal rotation shaft is provided with a first angle encoder for measuring the horizontal rotation angle.

[0007] In a preferred embodiment of the present invention, the pitch structure includes a pitch axis and a second drive motor that drives the pitch axis to rotate about a horizontal axis, and the pitch axis is provided with a second angle encoder for measuring the pitch angle.

[0008] In a preferred embodiment of the present invention, the control system is electrically connected to the first drive motor, the second drive motor, the first angle encoder, the second angle encoder, the laser probe structure, the wide-area search sensing unit, and the precision deviation sensing unit, respectively.

[0009] In a preferred embodiment of the present invention, the laser probe structure includes a laser emitter for emitting a measuring laser to a target ball mounted on the object being measured, a ranging unit for receiving the laser reflected back from the target ball for ranging, and an indicator light source for emitting an indicator laser coaxial with the measuring laser.

[0010] In a preferred embodiment of the present invention, the ranging unit includes laser interferometers, absolute rangefinders, and pulsed laser rangefinders.

[0011] In a preferred embodiment of the present invention, the wide-area search sensing unit includes one or a combination of visible light CCD, CMOS camera, infrared camera and lidar, and the wide-area search sensing unit identifies the target ball through an image recognition algorithm.

[0012] In a preferred embodiment of the present invention, the types of precision deviation sensing units include position-sensitive detectors and four-quadrant detectors, area CCD and CMOS devices.

[0013] The beneficial effects of the present invention are as follows: The present invention provides a laser tracker with automatic positioning function. The laser tracker has an automatic positioning structure, which can automatically identify the target, autonomously complete the initial positioning and re-locking, thereby improving the degree of automation and efficiency of measurement, and solving the problems of traditional equipment relying on manual operation, low positioning efficiency and insufficient degree of automation. Attached Figure Description

[0014] Figure 1 This is a front view of a laser tracker with automatic positioning function.

[0015] Figure 2 This is a left view of a laser tracker with automatic positioning function.

[0016] The components in the attached diagram are labeled as follows: 1. Base; 2. First drive motor; 3. Second drive motor; 4. First angle encoder; 5. Second angle encoder; 6. Pitch frame; 7. Laser emitter; 8. Ranging unit; 9. Wide-area search sensor unit; 10. Precision deviation sensor unit; 11. Control cabinet; 12. Horizontal rotation axis; 13. Pitch axis; 14. Extension arm; 15. Mounting base; 16. Support bracket. Detailed Implementation

[0017] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby providing a clearer and more explicit definition of the scope of protection of the present invention.

[0018] Please see Figure 1 and Figure 2 The embodiments of the present invention include: A laser tracker with automatic positioning function includes a laser tracker body, which includes a base 1, a horizontal rotation structure, a pitch structure, and a laser probe structure. The horizontal rotation structure is mounted on the base 1, and the pitch structure is mounted on the upper part of the horizontal rotation structure via a pitch frame 6. The laser probe assembly is fixedly mounted on the mounting base 15 of the extension arm 14 of the pitch structure. The system also includes an automatic positioning structure that can automatically identify the target, autonomously complete initial positioning and re-locking, thereby improving the degree of automation and efficiency of measurement and solving the problems of traditional equipment relying on manual operation, low positioning efficiency, and insufficient automation.

[0019] The horizontal rotation structure includes a horizontal rotation shaft 12 and a first drive motor 2 that drives the horizontal rotation shaft 12 to rotate around a vertical axis. The horizontal rotation shaft 12 is provided with a first angle encoder 4 for measuring the horizontal rotation angle.

[0020] The pitch structure includes a pitch shaft 13 and a second drive motor 3 that drives the pitch shaft 13 to rotate around a horizontal axis. The pitch shaft 13 is equipped with a second angle encoder 5 for measuring the pitch angle.

[0021] The laser probe structure includes a laser emitter 7 for emitting a measuring laser to a target ball mounted on the object being measured, a ranging unit 8 for receiving the laser returned from the target ball for ranging, and an indicator light source for emitting an indicator laser coaxial with the measuring laser. The indicator laser is visible light and is used to provide a visual alignment indication during automatic positioning.

[0022] The types of ranging units 8 include laser interferometers, absolute rangefinders, and pulsed laser rangefinders.

[0023] The automatic positioning structure includes a wide-area search sensing unit 9, a precision deviation sensing unit 10, and a control system.

[0024] The wide-area search sensing unit 9 is fixed on the top of the support bracket 16 perpendicular to the surface of the pitch frame 6, and has a first field of view. It is used to image the surrounding environment and identify the preliminary position information of the target ball. The preliminary position information includes at least the direction of the target relative to the wide-area search sensing unit 9.

[0025] The support bracket 16 consists of two vertical plates and a top plate. The two vertical plates are arranged on both sides of the pitch structure, and the top plate is arranged on top of the two vertical plates.

[0026] The wide-area search sensing unit 9 includes one or a combination of visible light CCD, CMOS camera, infrared camera and lidar. The wide-area search sensing unit 9 identifies the target ball through an image recognition algorithm based on the target ball's preset shape features, color features, reflective features and additional marking pattern features.

[0027] The precision deviation sensing unit 10 is mounted on the mounting base 15, adjacent to the laser probe structure. Its optical axis is parallel to the measuring laser of the laser emitter 7, and it has a second field of view smaller than the first field of view. It is used to detect the deviation between the center of the light signal returned by the target ball and the center of the field of view of the precision deviation sensing unit 10 when the measuring laser approaches the target ball, and generate a high-precision deviation signal.

[0028] The precision deviation sensing unit 10 includes position-sensitive detectors and four-quadrant detectors, area array CCD and CMOS devices.

[0029] The control system is installed in the control cabinet 11 next to the laser tracker body. The control system has a built-in motion control module and a signal processing module. The motion control module is used to generate motor drive signals according to position commands and feedback deviation signals. The signal processing module is used to process the image information of the wide-area search sensing unit 9 and the deviation signal of the precision deviation sensing unit 10.

[0030] The control system has a learning and memory function, which can record and store the final spatial angle position of the target ball that was successfully tracked last time or in the past. When it is started again, the laser probe structure is preferentially driven to point to the vicinity of the memorized angle position for rapid re-capture.

[0031] The control system is electrically connected to the first drive motor 2, the second drive motor 3, the first angle encoder 4, the second angle encoder 5, the laser probe structure, the wide-area search sensor unit 9, and the precision deviation sensor unit 10, respectively.

[0032] Working principle: Initialization and Target Search: After the system is powered on, the control system starts to run. The wide-area search sensing unit 9 continuously or as instructed performs large-scale imaging of the environment around the instrument, covering a wide space in front of the instrument. The image recognition algorithm processes the images captured by the camera in real time. This algorithm is trained to quickly identify the target ball in a complex background based on its preset features (such as the unique geometry of the spherical target, high reflectivity, or additional specific marking patterns). Once the identification is successful, the program calculates the pixel position of the target ball in the image and, combined with the camera's intrinsic parameters (focal length, principal point, etc.) and preset extrinsic parameters (the position and attitude of the camera relative to the coordinate system of the base 1), calculates the approximate azimuth angle (including horizontal and pitch directions) of the target ball relative to the base 1, thereby obtaining preliminary position information.

[0033] Rapid coarse positioning: The control system receives the preliminary position information (approximate horizontal and pitch angles of the target) from the wide-area search sensing unit 9. The motion control module in the control system converts this angle information into drive commands and sends them to the first drive motor 2 and the second drive motor 3 to rotate. This drives the laser probe assembly and the precision deviation sensing unit 10 mounted on the pitch frame 6 to rotate rapidly and smoothly, so that the laser probe structure roughly points to the approximate orientation of the target. During this process, the first angle encoder 4 and the second angle encoder 5 provide real-time feedback on the actual rotation angle of the axis system, forming a position closed loop to ensure the positional accuracy and stability of the rotation, allowing the laser beam to quickly enter the capture range of the next precision deviation sensing unit 10.

[0034] Precision Alignment and Locking: When the laser probe is roughly aligned with the target, the measuring laser emitted from the laser emitter 7 (which may include an invisible ranging laser and a coaxial visible indicating laser) will illuminate the vicinity of the target sphere. The precision deviation sensing unit 10 then begins operation. Its optical axis is strictly parallel to the measuring laser axis, but it has a field of view much smaller than that of a wide-angle lens (possibly only a few degrees), specifically designed to detect minute deviations between the laser spot and the center of the target sphere. The target sphere returns the laser beam along its original path, and the returned beam enters the precision deviation sensing unit 10. If the center of the laser spot does not precisely fall on the center of the target sphere, the position of the returned laser spot on the target surface of the precision deviation sensing unit 10 will deviate from the center point. The precision deviation sensing unit 10 immediately generates and outputs a... A high-precision deviation signal (usually an analog voltage or digital signal) clearly indicates the amount and direction of the beam's offset in the horizontal and pitch directions. Upon receiving this deviation signal, the control system immediately initiates high-bandwidth closed-loop feedback control. The signal processing module interprets the deviation, and the motion control module generates precise motor adjustment commands, controlling the first drive motor 2 and the second drive motor 3 to perform minute, typically step-like, rotations, continuously adjusting the laser direction in an attempt to reduce the deviation signal to zero. This is a dynamic convergence process; as the laser beam is continuously corrected, the deviation signal becomes smaller and smaller until the laser beam is precisely aligned with the geometric center of the target sphere. At this point, the deviation signal output by the precision deviation sensing unit 10 approaches zero, and the system enters a locked state.

[0035] Continuous tracking and data measurement: Once locked, the system automatically switches to tracking and measurement mode. When the target ball begins to move, the precision deviation sensing unit 10 immediately senses the new minute deviation signal generated by the movement. The control system reads the deviation signal in real time at an extremely high frequency (up to several kilohertz) and drives the first drive motor 2 and the second drive motor 3 to perform passive following motion, always keeping the laser beam precisely locked on the center of the moving target ball. While tracking stably, the laser ranging structure continuously measures the precise distance to the target ball, while the first angle encoder 4 and the second angle encoder 5 continuously read the real-time, high-precision horizontal angle and pitch angle. The control system fuses these three types of data (distance, horizontal angle, and pitch angle) in real time to calculate the precise three-dimensional rectangular coordinates of the target ball in space.

[0036] Target Loss and Intelligent Reacquisition: If the target is suddenly lost due to occlusion (causing the signal of the precision deviation sensing unit 10 to disappear), the control system will immediately determine that it has missed the target. The control system can automatically trigger the reacquisition program. Based on the learning and memory function of the control system, it can record and store the final spatial angle position of the target ball that was successfully tracked last time or in the past. When it is started again, the laser probe assembly is driven first to point to the vicinity of the memorized angle position for rapid reacquisition. The control system will first drive the laser probe structure back to the vicinity of the last recorded angle position before the target was lost for rapid search. At the same time, the control system will reactivate the wide-area search sensing unit 9 to re-search and identify the image in the vicinity of the last known orientation. Once the target is found again, the coarse positioning process of the second stage is immediately repeated to re-establish tracking.

[0037] Unlike existing technologies, this invention provides a laser tracker with automatic positioning function. This laser tracker has an automatic positioning structure that can automatically identify targets, autonomously complete initial positioning and re-locking, thereby improving the degree of automation and efficiency of measurement, and solving the problems of traditional equipment relying on manual operation, low positioning efficiency and insufficient automation.

[0038] In the description of this invention, it should be noted that all components are general standard parts or components known to those skilled in the art. Their structures and principles can be learned by those skilled in the art through technical manuals or conventional test methods. The terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the product of this invention is usually placed in during use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0039] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A laser tracker with automatic positioning function, comprising a laser tracker body, the laser tracker body including a base, a horizontal rotation structure, a pitch structure, and a laser probe structure, the horizontal rotation structure being mounted on the base, the pitch structure being mounted on the upper part of the horizontal rotation structure via a pitch frame, and the laser probe assembly being fixedly mounted on a mounting base of the extension arm of the pitch structure, characterized in that, It also includes an automatic positioning structure; The automatic positioning structure includes a wide-area search sensing unit, a precision deviation sensing unit, and a control system. The wide-area search sensing unit is fixed on the top of a support bracket perpendicular to the surface of the pitch frame. The support bracket consists of two vertical plates and a top plate. The two vertical plates are arranged on both sides of the pitch structure, and the top plate is arranged on top of the two vertical plates. The precision deviation sensing unit is mounted on the mounting base, adjacent to the laser probe structure; The control system is installed in the control cabinet next to the laser tracker body, and the control system has a built-in motion control module and a signal processing module.

2. A laser tracker with automatic positioning function according to claim 1, characterized in that, The horizontal rotation structure includes a horizontal rotation shaft and a first drive motor that drives the horizontal rotation shaft to rotate around a vertical axis. The horizontal rotation shaft is equipped with a first angle encoder for measuring the horizontal rotation angle.

3. A laser tracker with automatic positioning function according to claim 2, characterized in that, The pitch structure includes a pitch axis and a second drive motor that drives the pitch axis to rotate around a horizontal axis. The pitch axis is equipped with a second angle encoder for measuring the pitch angle.

4. A laser tracker with automatic positioning function according to claim 3, characterized in that, The control system is electrically connected to the first drive motor, the second drive motor, the first angle encoder, the second angle encoder, the laser probe structure, the wide-area search sensing unit, and the precision deviation sensing unit, respectively.

5. A laser tracker with automatic positioning function according to claim 1, characterized in that, The laser probe structure includes a laser emitter for emitting a measuring laser to a target ball mounted on the object being measured, a ranging unit for receiving the laser reflected back from the target ball for ranging, and an indicator light source for emitting an indicator laser coaxial with the measuring laser.

6. A laser tracker with automatic positioning function according to claim 5, characterized in that, The types of ranging units include laser interferometers, absolute rangefinders, and pulsed laser rangefinders.

7. A laser tracker with automatic positioning function according to claim 5, characterized in that, The wide-area search sensing unit includes one or a combination of visible light CCD, CMOS camera, infrared camera and lidar, and the wide-area search sensing unit identifies the target ball through an image recognition algorithm.

8. A laser tracker with automatic positioning function according to claim 1, characterized in that, The types of precision deviation sensing units include position-sensitive detectors and four-quadrant detectors, area CCD and CMOS devices.

Images