A modified integral resonant control scheme for vibration suppression of parallel kinematic mechanisms with flexible links

Abstract

A new modified integral resonant control (IRC) scheme is demonstrated herein for vibration suppression of the flexible links of parallel kinematic mechanisms (PKMs). Typically, the resonance frequencies and response amplitudes of the PKM links experience configuration-dependent variation within the workspace. To address these variations, a robust quantitative feedback theory (QFT) approach is utilised herein on a cantilever beam, with a variable tip mass as a proof of concept. The proposed IRC scheme is synthesised with the plant templates within the QFT environment to compare its: 1) robust stability; 2) vibration attenuation with the existing IRC schemes. It is shown that the proposed IRC scheme exhibits improved robustness, while it can maintain its vibration attenuation capability. The proposed IRC is subsequently implemented on a PKM flexible link. The simplicity of the proposed control system makes it a practical approach for vibration suppression of the PKM links, accommodating substantial configuration-dependent behaviour.