Research On Processing Methods Of Dynamic Position And Attitude Measurement Data Of Multiple Laser Trackers

With the in-depth integration of information technology and industrial manufacturing,the modern industrial product structure is increasingly complex,the size is increasing,and the requirements for measurement are becoming higher and higher.Large-scale dynamic posture measurement technology has an urgent practical demand.The laser tracker is widely used in large-scale dynamic position and attitude measurement due to its high measurement accuracy,wide range and high frequency.In this paper,based on the analysis of the existing theories and methods of data processing of the dynamic position and attitude measurement of the laser tracker,this paper focuses on the gross error detection technology and measurement accuracy evaluation method of the dynamic position and attitude measurement data of multiple laser trackers and the unified method of spatial reference and time reference between multiple laser trackers,designed a synchronous trigger based on rubidium atomic clock for precise punctuality and applied for a national invention patent.The specific research content is as follows:1.This paper analyzes the principle of dynamic position and attitude measurement of a single laser tracker,the unification of the spatial reference of multiple laser trackers and the principle of position and attitude calculation,etc.2.This paper proposes a method for unifying the time reference of multiple laser trackers.On the basis of the existing synchronous trigger with constant temperature crystal as the clock-keeping clock,a prediction model of the crystal time drift based on the ARMA-GARCH model is established,which provides high-precision compensation for the application of the synchronous trigger in a closed environment.A synchronous trigger based on a rubidium atomic clock as a clock-keeping clock is designed to further improve the punctuality accuracy of the synchronous trigger in a closed environment.3.This paper studies the gross error detection technology of the dynamic position and attitude measurement data of multiple laser trackers.First,this paper analyzes gross error detection methods based on mathematical statistics,such as the five-point cubic curve fitting method,median method,and interquartile range method,then,based on the a priori position information and trajectory information provided by the space circular trajectory generator,a gross error detection model based on the a priori constraints is established.Taking the observation value of the dynamic measurement of a circular trajectory generator as an example,the accuracy of gross error detection by the above four methods is tested.Aiming at the characteristics of the laser tracker dynamic position and attitude measurement data in the frequency domain,considering the wavelet analysis technology has good time-frequency characteristics,a gross error detection method based on the db4 wavelet basis function is proposed.Through experiments,the effectiveness of this method on gross error detection of laser tracker dynamic pose measurement data is verified.Finally,I use the default threshold method for wavelet denoising processing on the data after removing gross errors,study the influence of different wavelet decomposition layers and wavelet basis functions on the noise reduction effect.4.Quantitative analysis was made for the errors existing in various links of the dynamic position and attitude measurement system of multiple laser trackers.A method for evaluating the accuracy of the dynamic position and attitude measurement of multiple laser trackers is proposed.Using the rigid constraint conditions and the dynamic point position measurement and attitude measurement benchmarks provided by the space circular trajectory generator and the indium steel tetrahedral standard,the evaluation of the posture measurement accuracy at different motion speeds and different sampling frequencies is achieved.Experiments show that the dynamic position and attitude measurement of multiple laser trackers has a significant improvement over the single laser tracker in terms of measurement accuracy and measurement range.