CN-122016224-A - CTS test movement mechanism pose measuring device and mechanism pose calibration method

CN122016224ACN 122016224 ACN122016224 ACN 122016224ACN-122016224-A

Abstract

The application provides a CTS test movement mechanism pose measurement device and a mechanism pose calibration method, wherein the method comprises the steps of arranging a non-contact pose measurement system in a wind tunnel test section, comprising a calibration target rigidly connected with a parallel mechanism moving platform, arranging a plurality of detection targets on the calibration target, a target monitoring system in control communication connection with the pose measurement system, and being used for monitoring coordinate positions of the detection targets when a CTS test movement mechanism moves to each pose point according to a target pose point sequence, determining poses of the moving platform according to the coordinate positions of the detection targets acquired by the target monitoring system in the calibration process, obtaining a pose set, calling a mechanism parameter identification module written based on programming software according to the obtained pose set, and determining mechanism structural parameters by adopting a nonlinear least square method according to a deviation construction error equation of the nominal poses calculated by the pose set and a theoretical inverse solution model.

Inventors

XIE FENG
WANG SHUAI
CHEN TIANQI
WANG SHUAI
YAN WANFANG
ZHANG CHENKAI
WEI ZHONGWU
DONG JINGANG

Assignees

中国航天空气动力技术研究院

Dates

Publication Date: 20260512
Application Date: 20251230

Claims (10)

1. The utility model provides an automatic calibration device of CTS test motion mechanism position appearance which characterized in that includes: A non-contact pose measurement system is deployed in the wind tunnel test section, wherein the pose measurement system comprises a calibration target rigidly connected with a parallel mechanism moving platform, and a plurality of detection targets are arranged on the calibration target; The target monitoring system is in control communication connection with the pose measuring system and is used for monitoring the coordinate positions of a plurality of detection targets when the CTS test movement mechanism moves to each pose point according to the target pose point sequence; In the calibration process, the pose measurement system determines the pose of the movable platform according to the coordinate positions of a plurality of detection targets acquired by the target monitoring system to obtain a pose set, and invokes a mechanism parameter identification module written based on programming software according to the obtained pose set, and an error equation is constructed according to the deviation of the pose in the pose set and the nominal pose calculated by a theoretical inverse solution model, and the nonlinear least square method is adopted to identify and determine the mechanism structural parameters.
2. The automatic calibration device for the pose of the CTS test movement mechanism according to claim 1, wherein the target monitoring system comprises a calibration target provided with a plurality of marking points as detection targets, and is rigidly connected with a movable platform of the parallel mechanism; A multi-vision system which is controlled by the pose measuring system and surrounds the upper part of the wind tunnel test device and is used for capturing the marked points.
3. The CTS test motion mechanism pose automatic calibration device according to claim 2, wherein said target monitoring system comprises a multi-vision system and a first calibration target; The first calibration target comprises a first target plate, at least 4 high-reflection round marking points arranged in a specific asymmetric pattern are arranged on the upper surface of the first target plate, and the first calibration target is rigidly connected with the movable platform; The multi-vision system comprises a plurality of cameras which are respectively and uniformly arranged on the front upper side and the rear upper side rigid support of the wind tunnel test section, and all marking points which are arranged on a first calibration target are formed around and overlook to shoot.
4. The CTS test motion mechanism pose automatic calibration device according to claim 1, wherein said target monitoring system comprises a second calibration target provided with a plurality of reflective target balls and rigidly connected to a moving platform; and the laser tracker system is controlled by the pose measurement system and used for tracking the reflecting target ball, and the laser tracker system is communicated with the pose measurement system through the Ethernet.
5. The CTS test motion mechanism pose automatic calibration device according to claim 4, wherein said target monitoring system comprises a laser tracker system and a second calibration target; The second calibration target comprises a second target plate, at least 3 non-collinear reflecting target balls are arranged on the upper surface of the second target plate, and the second calibration target is rigidly connected with the movable platform through a flange; The laser tracker system is fixedly arranged on a connecting piece on the wall surface of the wind tunnel test section and is arranged in front of the second calibration target to realize that all the reflecting target balls are identified in a overlooking gesture, and the coordinate position change of a plurality of reflecting target balls is monitored when the CTS test movement mechanism moves and fed back to the gesture measuring system.
6. The method for calibrating the pose of the mechanism based on the CTS test motion mechanism pose measuring device is realized by any one of claims 1 to 5, and is characterized by comprising the following steps: The automatic pose data acquisition, namely loading a pre-planned target pose point sequence in a sub-verification space by an upper computer, and sending a positioning signal to a pose measurement system after a mechanism motion control system controls a parallel mechanism to move to a preset target pose; the pose measuring system automatically triggers the target monitoring system to collect the coordinate position change conditions of a plurality of detection targets after receiving the signals so as to determine the six-degree-of-freedom pose of the current moving platform; the method comprises the steps of identifying mechanism parameters, namely obtaining each pose in a pose data set, combining the corresponding nominal pose determined by a nominal kinematic model of the mechanism, and carrying out parameter identification on key mechanism structural parameters by adopting a least square algorithm to obtain the mechanism structural parameters; Updating the control model, namely updating the structural parameters of the mechanism into an inverse solution model of the motion controller of the mechanism to replace original nominal parameters so as to correct the kinematic model of the mechanism; The calibration effect calibration and iteration comprises the steps of planning a group of calibration pose points, acquiring the actual six-degree-of-freedom pose of the movable platform through an automatic pose data acquisition step by a pose measurement system, calculating errors of the pose with instructions, judging that the calibration of the sub-calibration space pose is qualified if the errors of the displacement and the pose meet a preset precision threshold, and automatically repeating the steps to carry out iterative calibration until the calibration of the pose is qualified if the errors of the displacement and the pose are not met; And (3) sub-checking space pose calibration iteration, namely judging whether the pose calibration check of all sub-checking spaces is completed or not, and if the pose calibration check of the next sub-checking space is not completed, completing the pose calibration check of the next sub-checking space based on the steps.
7. The method for calibrating the pose of a mechanism according to claim 6, wherein under the condition that the target monitoring system comprises a multi-vision system and a first calibration target, the step of automatically acquiring the pose data is specifically as follows: a1, loading a pre-planned positioning pose point sequence by an upper computer, controlling a parallel mechanism to move to a preset first positioning pose point by a mechanism motion control system, and sending a positioning instruction to a pose measurement system; A2, after receiving the instruction, the pose measurement system adopts a multi-vision three-dimensional reconstruction principle, acquires a two-dimensional image containing a first calibration target through the multi-vision system, triangulates a plurality of mark points through a triangulation method by combining the relative position relation and internal and external parameters between cameras, and calculates the three-dimensional coordinates of each mark point so as to calculate the displacement and six-freedom pose of the moving platform; and A3, repeating the step A1 to the step A2 to finish the determination of the attitude data of the movable platform under all preset target positioning attitude points.
8. The method for calibrating the pose of a mechanism according to claim 6, wherein under the condition that the target monitoring system comprises a laser tracker system and a second calibration target, the step of automatically acquiring pose data is specifically as follows: Step B1, loading a pre-planned positioning pose point sequence by an upper computer, controlling a parallel mechanism to move to a preset first positioning pose point by a mechanism motion control system, and sending a positioning instruction to a pose measurement system; Step B2, after receiving the instruction, the pose measurement system acquires the space coordinates of the reflecting target ball group of the second calibration target in real time by adopting a laser tracker, and further calculates the six-degree-of-freedom pose of the movable platform; and B3, repeating the steps B1-B2 to finish the determination of the pose data of the movable platform under all preset target pose points.
9. A computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the mechanism pose calibration method according to any of claims 6 to 8 when the computer program is executed by the processor.
10. A computer readable storage medium storing a computer program, wherein the computer program when executed by a processor implements the mechanism pose calibration method according to any of claims 6 to 8.

Description

CTS test movement mechanism pose measuring device and mechanism pose calibration method Technical Field The invention relates to the technical field of wind tunnel tests, in particular to a device for measuring the pose of a movement mechanism in a CTS test, and a method, a system, equipment and a medium for calibrating the pose of the mechanism based on a pose acquisition device. Background The capture trajectory system (Capture Trajectory System, CTS) wind tunnel test is a key means to study the safety separation characteristics of aircraft from stores, which requires accurate reproduction of the true drop trajectory of stores during blowing. The capability is highly dependent on whether a six-degree-of-freedom parallel mechanism supporting and driving the model can achieve high-precision pose positioning. The positioning error of the parallel mechanism is derived from a plurality of aspects, and mainly comprises machining errors and assembly errors of each component, structural deformation errors caused by temperature change and load action, vibration errors in the movement process and the like. Wherein geometric parameter errors (such as hinge point position deviation and rod length deviation) are main sources of static positioning errors and can account for 60-70% of the total errors. The kinematic calibration is an effective method for improving the absolute positioning accuracy of the parallel mechanism by measuring the deviation of the actual pose and the model predicted pose, identifying the actual geometric parameters of the mechanism and correcting the control model according to the actual geometric parameters. Currently, in CTS tests, a contact calibration method based on a three-coordinate measuring machine (such as a haustard absolute measuring arm) is generally adopted. According to the method, a plurality of characteristic points on a precise cross calibration frame fixedly connected with a movable platform are measured in contact by manually operating a measuring arm, and the current actual pose of the movable platform of the parallel mechanism is calculated. And (3) comparing the model with the nominal pose calculated by the inverse solution model of the mechanism and the reading of the motor encoder to construct an error model, and identifying geometric error parameters by utilizing algorithms such as a least square method and the like. In general, in order to ensure the accuracy of the calibration model in a larger working space, the whole working space is divided into a plurality of subareas to respectively carry out a large number of calibration and verification experiments, and if the error does not meet the requirement, the calibration needs to be carried out again: firstly, the manual operation is highly relied on, a measurer needs to lift a heavy measuring arm in a narrow (such as a diameter of 1.2 meters) wind tunnel test section for repeated operation for a long time, the labor intensity is high, and human errors are easily introduced due to fatigue. Secondly, the calibration process requires at least two persons to work cooperatively (one person operates control software and one person operates measurement equipment), so that the communication cost is high, and the requirements on professional quality of the personnel are high. Finally, the whole calibration process takes very long time, and usually takes up 2 to 3 whole days of the wind tunnel. Lengthy calibration times become bottlenecks limiting the efficiency of the test. In view of the foregoing, it is highly desirable to provide a calibration method for a CTS parallel mechanism that can achieve full automation, high precision and high efficiency, so as to thoroughly get rid of the dependency on heavy manual operation, shorten the calibration time, and improve the overall efficiency and safety of the test. Disclosure of Invention In order to overcome the problems in the related art, the present disclosure provides a method, a device, equipment and a medium for calibrating the pose of a motion mechanism in a CTS test, so as to solve the problems of low efficiency, high labor cost and high safety risk of the existing calibration method. One or more embodiments of the present disclosure provide an automatic calibration device for a pose of a CTS test motion mechanism, including: A non-contact pose measurement system is deployed in the wind tunnel test section, wherein the pose measurement system comprises a calibration target rigidly connected with a parallel mechanism moving platform, and a plurality of detection targets are arranged on the calibration target; The target monitoring system is in control communication connection with the pose measuring system and is used for monitoring the coordinate positions of a plurality of detection targets when the CTS test movement mechanism moves to each pose point according to the target pose point sequence; In the calibration process, the pose measurement system determines the pose of