Abstract: Input shaper can effectively suppress the residual vibration of the flexible mechanism.Its robustness is an important parameter to evaluate the amplitude and the frequency range of vibration reduction of input shaper,which can be obtained by analyzing the insensitivity of the sensitivity curve.In order to obtain stronger robustness,the typical input shapers are improved by adding higher-derivative and multi-hump constraint conditions.The improved input shaper can broaden the frequency range of the residual vibration suppression.The basic principle and robust analysis method of the high order zero vibration and zero differential and multi-hump extra-insensitive input shaper are introduced,followed by the application of these methods to a model of flexible parallel manipulator.The robustness of input shapers is analyzed by numerical simulation,and the insensitivities of various input shapers are compared.Moreover,according to the system response curve,the influence of the system resonance frequency change due to the vibration suppression capability of the input shaper is analyzed.Thus the performance of various input shapers' robustness is verified.The simulation results show that the robustness of the THEI input shaper is the highest,and the synthesized performance of the DHEI input shaper is the best.

Key words: input shaping, vibration suppression, robustness, higher-derivative, multi-hump