Dynamics and Robust Control of an Underactuated Torsional Vibratory Gyroscope Actuated by Electrostatic Actuator

Abstract

It has been shown that the underactuated MEMS gyroscopes provide inherent robustness against structural and environmental parameter variations. To further improve the performance of the systems, the electrical and mechanical coupling dynamics of the underactuated torsional gyroscopes with double oscillators actuated by a single electrostatic actuator is investigated in this paper. It is shown that the highly nonlinear coupling dynamics of the underactuated gyroscope systems can be transformed into the fifth-order linear systems even though the electrical uncertainties of the systems are considered. For the purpose of simplifying the structures of the underactuated torsional MEMS gyroscopes, an observer-based robust controller with considering structural uncertainties is presented on the basis of linear matrix inequalities (LMIs). The robust stability of the presented controller is also demonstrated by some numerical simulations on a three-degreeof-freedom underactuated MEMS gyroscope. It is shown that the LMI-based robust controller can accommodate both large initial errors in the system state and bounded uncertainties in the structural parameters of the system.

A reliability model for load-sharing k-out-of-n systems subject to soft and hard failures with dependent workload and shock effects

“…In most cases, MEMS is a load-sharing system where multiple micro-engines work together to perform more reliably [4,13]. The system has been widely applied to many intelligent mechatronic systems, and its reliability has been studied extensively [9,27]. A 2-outof-4 load-sharing MEMS with four identical micro-engines is utilized as a realistic application to illustrate the effectiveness and modeling capabilities of the proposed model in this paper.…”

Conceptual method for the detailed analytical calculation of capacitance matrix elements in variable capacitance synchronous machines

“…Moreover, the use of this type of machine in the magnetic field sensitive areas, which may cause unwanted magnetic fields, such as MRI/fMRI devices can be a good choice [6]. The use of electrostatic force for other interesting industrial applications such as micro‐electromechanical systems [7], micro‐switches [8], micro‐pumps [9], micro‐valves [10], electrostatic bearings [11,12] and electrostatic gyroscopes [13] is also observed.…”

Operation Capability Analysis and Experiments of Underactuated Compliant Multi-Fingered Hands

“…In order to reduce the cost of the systems and promote the extensive applications of multi-fingered robot hands, underactuated multi-fingered robot hands have been given many investigations in robotics field in recent years [1][2][3][4][5][6][7][8][9][10]. Different from the concept of underactuation in dynamical robotic systems such as underactuated manipulators [11], underactuated surface vehicles [12], dynamically legged robot systems [13], and underactuated gyroscopes [14] etc., of which the static equilibrium configurations are generally not stable since some free passive degrees of freedom (DOF) are involved in the mechanisms or the systems only work in dynamical mode, the underactuated multi-fingered hands [1] generally belong to a class of low-speed manipulation systems, of which the static equilibrium configurations are stable since the passive DOF of the mechanisms are generally installed elastic elements [4].…”