Concurrent Design of Input Shaping and Vibration Absorbers

Systems that exhibit flexible dynamics are susceptible to vibration caused by changes in the reference command, as well as, from external disturbances. Feedback control is an obvious choice to deal with these vibrations, but in many cases, it is insufficient or difficult to implement. Input shaping has proven beneficial for reducing vibration that is caused by changes in the reference command. However, input shaping does not deal with vibration excited by external disturbances. On the other hand, vibration absorbers have long been used to decrease vibration from external sources, particularly sinusoidal disturbances. In this paper, vibration absorbers and input shaping are designed concurrently to reduce vibration from both the reference command and external sources. The usefulness of this combined approach for dealing with both external and reference command disturbances is demonstrated through computer simulations.