NEARMINIMUMTIME SLEWING AND VIBRATION CONTROL OF SMART STRUCTURES

Abstract We present methodology for design of globally stable tracking controllers for both large angle slewing and vibration suppression of flexible space structures, which makes use of both reaction wheel torquing and piezoelectric actuation. A mathematical model is developed using the Finite Element Method. For illustration, we consider a flexible space structure configuration consisting of a reaction wheel mounted on a central hub and four cantilevered appendages to which piezoelectric actuators and sensors are attached. Lyapunov stability theory is applied to a hybrid ordinary/partial differential equation model of the dynamics to establish a stable controller for simultaneous slewing and vibration suppression, utilizing a hybrid set of sensors and actuators: piezoelectric sensors/actuators, and a reaction wheel. This control law ?hands off? automatically and seamlessly from tracking a large motion reference trajectory to a simple output feedback law for the terminal ?end game? vibration arrest region. The formulation is such that the reaction wheel and piezoelectric control inputs are independently stabilizing and can be either simultaneously or independently tuned over a known stable region of gain space. Simulations are presented which establish a basis for our conclusion that this controller is very attractive for a class of practical applications.

NEARMINIMUMTIME SLEWING AND VIBRATION CONTROL OF SMART STRUCTURES Chapter