Self-Calibration And Posture Solution For Posture Measurement System Based On Laser Multilateral Method

The large-scale spatial posture measurement technology can acquire the coordinates and attitude of the measurement target simultaneously.In this paper,the spatial posture measurement system based on the laser multilateral method was studied.It mainly studied two parts,coordinate measurement and posture measurement.A mathematical model of the measurement system was established,then the actual system was built,at the end,the accuracy of this system was verified by simulation and experiment.The main research contents included:(1)The main instrument used in the large-scale position measuring device was the laser tracking interferometer,and the accuracy and stability of laser tracers were analyzed through instrument ranging experiment and environmental parameter compensation experiment.(2)Based on the principle of laser multilateral method,the laser multilateral coordinate measurement model was established,and the four-beam laser tracking system for coordinate measurement was established.The system parameters and coordinate values were calculated by using redundant information provided by multistation.An improved self-calibration algorithm using standard length weighting was proposed.Firstly,the standard lengths were arranged in the X,Y,and Z directions,and then the new self-calibration optimization function was constructed by using the standard lengths.The coordinate measurement accuracy was further improved by increasing the weight of the corresponding optimization function.In the measurement range between 7.0 m and 8.3 m,the coordinate measurement accuracy was better than 9.5 ?m.(3)Four-beam laser tracking system and six-beam laser tracking system for coordinate measurement were established,self-calibration and coordinate solution can be solved by these two coordinate measurement systems.The influence of measurement beam quantity on coordinate measurement accuracy was analyzed.(4)A new method of posture measurement based on six-beam laser tracking system was proposed.6 laser tracers were used to track 3 reflectors for posture measurement,a measurement model of the posture measurement system was constructed.There was no redundant information in this system,a new self-calibration method based on stepwise calibration was proposed to realize the self-calibration of non-redundant system.The new self-calibration method and posture calculation algorithm were studied and verified.The posture measurement error was better than 13.6 ? in the 30 ° measurement range.