Abstract: This paper investigates the dynamic nonlinear characteristic of wrist force sensor in the frequency domain.The reasons for dynamic nonlinearity are analyzed,and the determining methods of time and frequency domain are studied.The sensor's transfer functions of linear and nonlinear are estimated.When input is non-Gaussian signal, the solution of quadratic nonlinear transfer function is presented.The determining method of main nonlinear frequency range is discussed.The constructed system is simulated,and the experimental data are analyzed.The results indicate that the nonlinear analyzing method can describe the sensor's dynamic characteristic more accurately.

Key words: wrist force sensor, quadratic transfer function, estimation of frequency domain, dynamic nonlinearity