Investigation of Performance and Sensitivity of S-Curve Motion Profiles on Reduction in Flexible Manipulator Vibrations

In flexible manipulators, it is crucial to suppress the end-point vibrations. Velocity motion profile which is used to actuate a manipulator is important to reduce the vibrations, especially during high-speed motions. In this study, effect of three different seven segment velocity motion profiles on the end-point transient and residual vibrations of a flexible manipulator was investigated experimentally and by performing finite element simulations with ANSYS. These motion profiles were third-order polynomial S-curves and two different trigonometric (harmonic and pure sinusoidal) S-curve motion profiles. Symmetrical velocity motion profiles were used, and time parameters of the motion profiles were selected either half-integer multiples or integer multiples of flexible manipulator's natural period. The results obtained from the experiments were compared with the transient analysis results obtained from ANSYS. The effects of time parameters of all motion profiles on endpoint vibrations were shown by comparing them in terms of amplitudes. Errors in the natural frequency measurements of the flexible manipulator change the time parameters of the motion profiles, and this change adversely affects the endpoint passive vibration control. The sensitivity of passive control results to 4% natural frequency measurement error is shown for all motion profiles.