End-Point Vibration Suppression in Flexible Servo Systems Based on Improved Two-Mode Shaper

In industrial servo systems, components with lightweight materials and large size are susceptible to deformation and vibration due to their inherent flexibility. This study proposes vibration suppression control strategy using an improved two-mode shaper as a solution to the multi-modal vibration problem in servo systems. The proposed method is capable of effectively suppressing the lowest two orders of vibration, which have the greatest impact on the end-point positioning. The proposed method improves the design approach of two-mode input shapers and addresses the issue of the conventional simultaneous two-mode (ST) shaper amplifying vibration at unmodelled frequency. Furthermore, this improved two-mode shaper is capable of reducing the delay introduced to the system compared to the conventional convolved two-mode (CT) shaper for specific mode ratios. Most notably, the proposed shaper has a straightforward analytical solution expression, which is more suitable for implementation in industrial servo systems. The proposed method was both simulated and experimentally compared to the conventional input shaping methods. The results highlight the effectiveness of the improved two-mode shaper in suppressing residual end-point vibration and demonstrate its advantages across different types of metric trade-offs.