The Flexible Structure Of The Input Shaping Control Strategy

Input Shaping is a feedforward control technique for reducing vibrations in computer controlled machines. The method works by creating a command signal that cancels its own vibration. That is,vibration caused by the first part of the command signal is canceled by vibration caused by the second part of the command. Input shaping is implemented by convolving a sequence of impulses,an input shaper,with any desired command. The shaped command that results from the convolution is then used to drive the system. If the impulses in the shaper are chosen correctly,then the system will respond without vibration to any unshaped command. The amplitudes and time locations of the impulses are obtained from the system's natural frequencies and damping ratios. Shaping can be made very robust to errors in the system parameters.About this thesis,we first expressed the importance of the reference input command to the system response. Then we introduced the input shapings:ZV(zero vibration),ZVD(zero vibration and derivative),EI(Extra-insensitive) etc. And we apply the MERV(minimized expected residual vibration) input shaping to the model of the type drive head system . We optimized to derive the MERV input shaper and compare it to other input shapings. Through the comparison,we can find out that the MERV shaping yield the better performance than the others. We can also derive the hybrid input shapers if we simplify the optimal process.The recent research about input shaping focus in the open-loop. In this thesis,the closed-loop input shaping is the focus. We would discuss how to design input shaper combining the PD control and stating feedback control. Because the input shaping delay the input,and we would discuss the stability of the closed-loop input shaping system . We would design the full stated feedback control for the delayed system.In the final,we would discuss how to design input shaper for the multi mode system. Combining the H-infinite robust control technique,we designed the multi-mode input shaper.