A robust motion design technique for flexible-jointed manipulation systems

This paper presents a robust input shaping technique that significantly reduces (almost eliminates) the residual vibration of manipulation systems typified by a flexiblejointed robot manipulator. The technique consists of two stages. In the first stage, a ramp function is superimposed onto the main trajectory to be preshaped. In the second stage, the outcome of the first stage is convolved with a sequence of two impulses. The robustness of the technique to the uncertainties in the system natural frequency and damping ratio are quantified through simulation and experimental evaluation. Simulation and experimental results demonstrate that the technique is not only effective in reducing the residual vibrations, but also it is robust to the uncertainties of as high as∓35% from the ideal value of the system natural frequency. Further, it has been found that the proposed input shaping technique is insensitive to the uncertainties in the damping ratio. The results allow us to suggest that the proposed technique is versatile and robust enough to apply it to the motion design of any flexible-jointed manipulation system making a point-to-point motion.