Stability analysis of parallel robot under linear quadratic regulator control based on genetic algorithm optimization

Through dynamic modeling and state space analysis of 3-UPS parallel robot, the Linear-Quadratic-Regulator (LQR) control method based on Genetic Algorithm (GA) optimization was used to make control simulation for 3-UPS parallel robot. Combining with the multi-body system vibration theory, the terminal stability of the robot was analyzed under three conditions with MATLAB software and ADAMS software for co-simulation. The conditions were the external load was applied to the moving platform, the random vibration was applied to the fixed platform and the compound interference was applied to the fixed platform. The results showed that under GA-optimized LQR control, the decay time and vibration amplitude of the vibration of robot moving platform were significantly reduced, and the resonance peak was also significantly reduced, but the vibration reduction effect at high-frequency vibration was not obvious. The resonance frequency in centroid x and y direction of robot moving platform were kept at about 5 Hz, while the resonance frequency in z direction had a significant backward shift phenomenon, gradually approaching the high frequency (10 Hz). This research provided a theoretical basis for analyzing the stability and working accuracy of parallel robots. © 2022, Editorial Department of CIMS. All right reserved.