Input shapers with uniformly distributed delays

Input shapers with time delays have proved useful in many applications related to controls for various flexible devices, for example flexible manipulators and cranes. In the paper, modifications of classical signal shapers ZV (zero vibration) and ZVD (zero vibration derivative) that use uniformly distributed delays instead of lumped delays are proposed. The shaper parameters, i.e. gains and time delays, are determined using spectral approach. The objective is to compensate the undesired oscillatory couple of system poles by the dominant couple of shaper zeros. Next, the spectral and frequency features as well as robustness issues are investigated. In all these aspects, the shapers with distributed delays show better characteristics compared to classical signal shapers. The theoretical results are verified on a laboratory crane system.