Vibration Control of a Flexible Spacecraft System With Input Backlash

Abstract

In this paper, we deal with the vibration control problem of a flexible spacecraft system with unknown external disturbance and uncertain input backlash nonlinearity. The considered system is described by two partial differential equations and an ordinary differential equation as governing equations, and by ordinary differential equations as boundary conditions. The backlash nonlinearity is reformulated into the desired control input associated with an extra input nonlinear error. This input error and the external disturbance are combined into an unknown “disturbance-like” item. Two boundary control inputs are designed at the center body of the spacecraft, compensating for the unknown upper-bound of such items by applying proper online updating laws. As a result, the vibration of both solar panels of the flexible spacecraft is suppressed and their angle positions are regulated in the desired region. The numerical simulations are provided to verify the control performance of the proposed controls by the choice of proper parameters.

Keywords

• Vibration control
• adaptive control
• flexible satellite
• input backlash