Inverse optimal sliding mode control of spacecraft with coupled translation and attitude dynamics

Abstract

Project Period : 2 yearsThis research studies new robust optimal control strategies for spacecraft position and attitude tracking maneuvers in the presence of external disturbances. Two optimal position and attitude controllers are developed to achieve asymptotic convergence to the desired position and attitude. The first optimal control law is designed based on the inverse optimal control concept using Sontag-type formula and a control Lyapunov function. For the second control law, the optimal Lyapunov approach is used to design an optimal position and attitude controller. Then robust optimal position and attitude controllers are designed by using an integral sliding mode control method to combine a second order sliding mode controller with the derived inverse optimal controller or optimal Lyapunov controller. Both developed robust optimal controllers can minimize a performance index and ensure the stability of the closed-loop system and attenuation of external disturbance. Besides, an inverse optimal controller with input saturations is designed to achieve asymptotic convergence to the desired translation and attitude and avoid the unwinding phenomenon. Later, a new sliding mode disturbance observer is also proposed to compensate for the total disturbances. A rigorous Lyapunov analysis is employed to ensure the finite-time convergence of observer error dynamics. An example of position and attitude tracking maneuvers is presented and simulation results are included to show the performance of the proposed controllers.

Inverse Optimal Attitude Stabilization of Flexible Spacecraft with Actuator Saturation

“…With > 0 and > 0, this ensures that ( ) is positive definite. Taking the first derivative of with respect to time, we havė=̇+̇+̇, (33) where by substituting (18), (15), and 24into (33)…”

Fast terminal sliding‐mode finite‐time tracking control with differential evolution optimization algorithm using integral chain differentiator in uncertain nonlinear systems

“…Sliding‐mode control has many attractive features such as insensitivity to the model errors and parametric uncertainties . Given its advantages, SMC provides powerful techniques to complicated nonlinear dynamic systems for tracking control, including robotic manipulator systems, active suspension vehicle systems, induction motor drive systems, power systems, and spacecraft systems …”

“…1,2 Given its advantages, SMC provides powerful techniques to complicated nonlinear dynamic systems for tracking control, including robotic manipulator systems, 3 active suspension vehicle systems, 4 induction motor drive systems, 5,6 power systems, 7 and spacecraft systems. 8 The tracking problems using evolutionary optimization in complicated nonlinear systems attract much more attention. Evolutionary optimization algorithms are considered as a powerful optimization tool in solving nonlinear and complicated search spaces.…”

Robust adaptive relative position and attitude control for spacecraft autonomous proximity

“…Moreover, dual quaternion was proposed for relative attitude and relative position motions in [25]- [27]. Recently, based on the quaternion attitude dynamics, an inverse optimal sliding mode controller was designed for spacecraft relative pose motion in [28]. Except for singularities of quaternion and modified Rodrigues parameters, they also have ambiguities in representing an attitude.…”

“…Proof Let V = V 1 + V 2 be the Lyapunov candidate of complete system. Using (28) and (48), the bound of V can be given as…”