Multimode Input Shaping Control of Flexible Structures Using Frequency Modulation

Abstract

Bulky rigid robotic arms require significantly large energy-consuming actuators. Lighter flexible robotic manipulators have many advantages over rigid manipulators in terms of cost, energy consumption, and speed. However, their structural flexibility compromises operation precision. This paper presents a multimode frequency-modulation input shaping control strategy for a flexible hanging beam performing rest-to-rest maneuvers. Frequency-modulation input shaping is used to produce shaped acceleration commands to the beam support. Model-based feedback is used to modulate the frequencies of the beam so that all higher mode frequencies become odd-integer multiples of the fundamental frequency of the feedback system. Single-mode input shaping techniques are implemented to eliminate vibrations in all modes of the model-based feedback system, and hence, the flexible beam. Numerical simulations are used to demonstrate the performance effectiveness of the proposed strategy.