Method And Experimental Research On Static Decoupling Of Piezoelectric Six-axis Accelerometer

Six-axis accelerometer is a sensor that simultaneously measures the information of three-axis linear acceleration and three-axis angular acceleration in space,and can realize a comprehensive perception of the motion state of the object.Because of the diversity and convenience of the sensor in aspect of information acquisition,it has broad application prospects in the fields of robotics,aerospace,health monitoring and other fields.However,for a MIMO system,there is always some coupling characteristic between the inputs and outputs,which affects the performance of the sensor.Therefore,it is important to carry out research work on static coupling for improving the measurement accuracy of the sensor.In this paper,the pre-developed piezoelectric six-axis accelerometer is taken as the research object,and the static decoupling method and experimental research of the sensor is carried out.Based on the basic principle of the sensor,the static coupling characteristic of the sensor is studied,and the evaluation indexes of the decoupling effect are discussed.Combined with the demand to improve decoupling performance of the sensor,the static decoupling method research of the sensor is carried out,and the offline solution is carried out to verify.The static experiment system is built,and the experimental study of static online measurement of the sensor is completed.The main research work is as follows:(1)The static coupling characteristic of the sensor is studied.Starting with the structural model of the sensor,the sign and amplitude characteristic of the sensor's output signals is analyzed,and the characteristic relationship between its output signals is derived.The coupling form between the sensor's output signals and the measured accelerations is analyzed,and the factors that affect the sensor's static coupling are studied.Combined with the measurement characteristic of the sensor,the evaluation indexes of the static decoupling effect are discussed,and the rationality is demonstrated.(2)The static decoupling methods of the sensor are compared and studied.Based on the basic characteristic of sensor's inputs and outputs,the static linear decoupling methods of the sensor are studied.Starting with the nonlinear error of the linear solution of the sensor,the static nonlinear decoupling method of LS+SVR hybrid compensation is studied.Starting with the nonlinear fitting error of the sensor's original output voltage,the static nonlinear decoupling method of voltage nonlinear mapping is studied.Combined with the static experimental data of the sensor prototype,using the MATLAB tool,an offline solution experiment study is conducted to verify the feasibility of the static decoupling methods studied.(3)An online measurement experiment system of the sensor is established and the experiment is conducted.According to the static test characteristic of the sensor,an angular vibration device based on a stepper motor is designed.Combined with the static decoupling methods studied,a static decoupling online measurement software based on the LabVIEW platform is developed.Using the sensor prototype,the online measurement experiment of the piezoelectric six-axis accelerometer is completed,which verifies the feasibility of the static decoupling method studied.In this paper,based on the analysis of the static coupling of the piezoelectric six-axis accelerometer,the static decoupling methods of the sensor are studied to improve the measurement accuracy of the sensor.It provides a reference for the static decoupling research of this type of sensor.