Research on Point-to-Point High-Speed and Low-Vibration Motion Planning Method Considering Time-Frequency Characteristics

To enhance the machining efficiency and positioning accuracy of feed systems during high-speed point-to-point motions, and to address the significant vibrations induced by spectral excitation of motion commands during high-speed operation, a motion planning method considering time-frequency characteristics is proposed to generate high-speed, low-vibration motion commands. This method constructs a motion command described by a 5th-order B-spline representation in the time domain, and integrates the time-frequency characteristics of the motion command into the planning process. On this basis, the short-time Fourier transform is utilized to derive analytical expressions for the spectral components of the acceleration command over different time intervals, and constraint equations for these spectral components are established in combination with the system’ s resonance frequency bands. By formulating a time-optimal motion command planning model that considers vibration suppression, and incorporating kinematic constraints as well as the time-frequency spectral component constraints of the acceleration command, high-speed, low-vibration motion commands are generated. Numerical simulations demonstrate that the proposed method can significantly reduce the amplitude of spectral components that excite system resonance, thereby improving the dynamic characteristics during motion. Experimental results on a flexible cantilever beam feed system show that, compared with the S-curve and asymmetric S-curve velocity planning methods, the proposed method can still achieve a reduction of over 50% in system vibration and a shortening of more than 40% in total positioning time, even in the presence of modeling disturbances.