Research On Dynamic Measuring And Positioning Technology Of Accurate Laser Positioning System (ALPS) In Large-scale Space

In large-scale equipment manufacturing system,the precision control technology of large components or sub-assembly production and assembly is one of the key technologies in the whole equipment manufacturing process,and digital measurement technology is the core of precision control in the production and assembly process.With the development of large equipment manufacturing technology,many engineering applications require on-site real-time monitoring of the spatial posture of components to complete multi-point docking tasks,or need to implement full-cycle precision tracking from design,production to size inspection.The laser tracker can't meet the task requirements of multi-point real-time positioning and parallel measurement gradually,so the distributed measurement system based on the front rendezvous measurement field deployment can be developed rapidly.The accurate laser positioning system(ALPS)previously studied by the research group is a distributed coordinate measurement system developed for large-scale spatial measurement and positioning problems.It has excellent characteristics such as stable measurement accuracy,multi-target parallel positioning,and real-time attitude calculation,and has broad application prospects in aerospace,shipbuilding,industrial automation and other fields.At present,the measurement error of ALPS system in static scenes can reach ±0.2 mm,but the error in dynamic scenes is extremely unstable.Therefore,other technologies need to be introduced to assist in solving the problem of dynamic measurement accuracy.Based on the static measurement model of ALPS and the measurement model of strapdown inertial measurement unit(IMU),this paper studies a dynamic measurement and positioning technology based on multi-sensor fusion,which solves the problems of autonomous navigation,blind area estimation and high frequency data refresh,and expands the function of ALPS in dynamic measurement and positioning tasks.This paper mainly studies and discusses the ALPS dynamic measurement and positioning technology from the aspects of ALPS dynamic error compensation,IMU pose measurement principle,fusion system calibration and positioning method,fusion system hardware platform design,calibration and positioning performance verification.The main work is as follows:1.Based on the analysis of the error generation process of ALPS in dynamic measurement and positioning,the paper explores the error formation mechanism of dynamic measurement system of ALPS,expounds the measurement error mechanism and compensation method of IMU,and studies the error compensation method combining IMU measurement data onto APLS positioning data.2.Aiming at the measurement system of ALPS and IMU fusion,the data model of ALPS and IMU is established by using MATLAB tool software,and this paper discusses the measurement data fusion method based on extended Kalman filter theory about the actual scene.The rationality of data fusion based on the loose couples is verified by data simulation.3.Based on the actual performance parameters of physical devices,the coordinate system processes physical model and MATLAB data simulation model of IMU inertial navigation system and ALPS measurement system are established.The calibration method of fusion system based on space rotation attitude constraint is discussed,and the correctness of system calibration theory is verified by simulation experiments.4.Based on Xilinx Zynq 7000 platform,a high-performance embedded data acquisition processor is designed,and the fast solution method of ALPS single frame data is explored.The relevant drive algorithm is solidified into the front-end processing equipment,and the data output frequency of ALPS system is increased to 35 Hz,which provides the basis for IMU data fusion correction process.5.According to the extended Kalman filter data fusion method,the calibration experiment and linear trajectory fitting experiment are designed based on the front-end equipment of fusion measurement and processing.The experimental results show that the final three-axis calibration errors of the system calibration method designed in this paper are±(0.382°,0.537°,0.463°),and the linear trajectory fitting error is within±2.388 mm,which verifies the feasibility of integrating IMU measurement data into ALPS system to improve the overall dynamic measurement ability,so that the ALPS/IMU fusion system can be applied in the scene requirements such as slow AGV navigation.