Research On Dynamic Decoupling Method Of Six-Axis Force Sensor

Intelligent main on behalf of the development direction of modern equipment, the main characteristics of the intelligent embodied the independent operation in the non specific environment, environment perception is a precondition to achieve autonomy. Mechanical quantity is the important physical parameters, mechanical quantity detection plays a very important role in the field of intelligent equipment. Six-axis force sensor can detect the full information of three-dimensional space, which is the most complicated structure and the highest comprehensive technical level in the field of force sensor. Modern six-axis force sensor generally adopts the composite beam as elastic structure, that exists the coupling between inter dimensional. On the basis of the six-axis force sensor stress state, there are static and dynamic coupling between inter dimension. According to the mechanical characteristics of six-axis force sensor, in the aspect of static coupling relation determined and calibration, domestic and foreign scholars have done in-depth study, made a relatively systematic and mature research results; Because of the complexity of the elastic structure, to reveal the dynamic characteristics especially dynamic coupling relation, also the lack of theoretical support system. With the continuous improvement of equipment performance, especially the response speed increase, the dynamic measurement error of sensor can not be ignored, dynamic coupling is an important source of six axis force sensor dynamic errors, dynamic decoupling is the main way by compensation method to decrease the dynamic coupling error.In order to systematically explore the dynamic decoupling method for multi axis force sensor,this paper adopts the analytic method, and mathematical estimation, and through experimental calibration is completed on the dynamic output signal acquisition. Six-axis force sensor with the elastomer as the research object, based on the theory of vibration mechanics, Using the analytic method to calculate the analytical expressions of six-axis force sensor dynamic strain, and as mathematical estimation to simplify the results, thus initially pushed the dynamic coupling relation, provide theoretical and data basis for revealing the dynamic decoupling of six-axis force sensor. In this paper, employing the dynamic performance test method of frequency response in the experimental calibration, the excitation device was electromagnetic vibration exciter, with the design of control circuit dynamic test, the harmonic frequency and amplitude can be generated continuously controllable excitation force, to provide a guarantee for the experimental research on decoupling of six-axis force sensor. The main research work in the paper is as follows,(1) Take the structure decomposition method divided elastomer of six-axis force sensor into several sub beam, the deformation analysis of sub beams, in a different direction under dynamic load, dynamic strain effect of corresponding loads, and the results are simplified, get the dynamic strain output graphics by mathematical simulation, to verify the correctness of the analytical expression, combined with linear coupling mapping relationship, to obtain the coupling matrix of six axis force sensor.(2) According to the input form of dynamic load, to establish the linear instantaneous model algorithm, using two kinds of decoupling algorithm, respectively by the kurtosis and negentropy as non Gauss criterion, Through the mathematical simulation and performance indexes to make a comparative study of decoupling results.(3) Analysis of the structure and the working principle of electromagnetic exciter, and given the output characteristics of electromagnetic vibration exciter. Put forward the double closed loop control system, which is the current loop and excitation force feedback loop. And design of an electromagnetic control circuit of dynamic test excitation force, at the same time do the actual circuit testing.In this paper, the main innovative points are as follows,(1) Using sinusoidal excitation with different frequency and amplitude as dynamic load of six-axis force sensor, by Fu Liye transform the composite signal into sine excitation signal, the study is more convenient for engineering application.(2) Based on the theory of blind signal processing, combined with the characteristics of input and output, establish the linear instantaneous model, two kinds of decoupling algorithm is proposed for the realization of the online, real-time dynamic decoupling guidance.