Using input command pre-shaping to suppress multiple mode vibration

Spacecraft, space-borne robotic systems, and manufacturing equipment often utilize lightweight materials and configurations that give rise to vibration problems. Prior research has led to the development of input command preshapers that can significantly reduce residual vibration. These shapers exhibit marked insensitivity to errors in natural frequency estimates and can be combined to minimize vibration at more than one frequency. A method for the development of multiple mode input shapers which are simpler to implement than previous designs and produce smaller system response delays is presented. The new technique involves the solution of a group of simultaneous nonlinear impulse constraint equations. The resulting shapers were tested on a model of MACE, an MIT/NASA experimental flexible structure