Research On Measurement Algorithm Of Parallel Six-axis Force Sensor Based On Reconstruction Theory

At present,with the rapid development of science and technology,the machinery manufacturing industry is moving towards the direction of fine processing.High precious measurement is very necessary in it.Meanwhile,the requirements are very strict for equipment in aerospace,national defense and other fields.It is also important to ensure the accuracy,stability and adaptability of the measurement system.This thesis is written for the requirement of high-precision measurement of sensors in measurement tasks.Based on the reconfigurable theory,the measurement algorithm of the parallel six-axis force sensor is researched.Researching from stiffness reconstruction algorithm,dimension reconstruction algorithm,fault-tolerant reconstruction algorithm and sensor static calibration experiment,it provides a certain reference value for the research of parallel six-axis force sensor measurement algorithm.Firstly,based on the small deformation hypothesis and deformation superposition principle,the stiffness modeling algorithm of parallel six-axis force sensor is established.The static mapping matrix of parallel six-axis force sensor is calculated.On this basis,the stiffness algorithm of parallel six-axis force sensor focusing on overload is established by introducing the reconstruction theory.Comparing the static mapping errors before and after reconstruction,the result that the error after reconstruction is less than before reconstruction is concluded and it verifies the correctness of stiffness reconstruction algorithm.Secondly,based on segmentation calibration and least squares,the virtual calibration of the sensor is carried on.And according to the result of virtual calibration,the dimension reconstruction algorithm of parallel six-axis force sensor is inferred.The dimension reconstruction measurement model corresponding to all feasible measurement structure schemes is established.The optimal configuration of redundant branches is carried out,and the optimal measurement model of sensors under various external loads is calculated.It lays a foundation for the research of model reconstruction algorithm based on adaptive measurement task requirements.Thirdly,the possible faults of sensors under complex working conditions are simply analyzed and classified.The fault-tolerant reconstruction algorithm is established for different fault types.Weather normal work can continue after failure is also analyzed.The fault-tolerant characteristics of the parallel six-axis force sensor are further verified,and the measurement accuracy of the sensor is improved.Finally,the static calibration experiment of parallel six-axis force sensor is carried out.The errors of sensor are analyzed based on calibration data.It is found that the measurement error of the sensor is within the allowable range.According to the experimental data,the dimension reconstruction measurement model and the fault tolerant restruction measurement model after signal fault corresponding to all feasible measurement structure schemes are established.It is found that the errors are in accordance with the theoretical results.Thus,the correctness of the dimension reconstruction algorithm and the fault tolerant reconstruction algorithm after signal fault are verified.