Physics

Control engineering

Aerospace engineering

Settling time

Nonlinear system

Mathematics

Sliding mode control

Economic growth

Agronomy

Biology

Adaptive control

Inertia

Engineering

Step response

Mathematical analysis

Actuator

Artificial intelligence

Attitude control

Economics

Controller (irrigation)

Control (management)

Convergence (economics)

Computer science

Quantum mechanics

Spacecraft

Control theory (sociology)

Angular velocity

Classical mechanics

Upper and lower bounds

IEEE Transactions on Aerospace and Electronic Systems

This paper addresses the problem of adaptive fixed-time attitude stabilization for uncertain rigid spacecraft with inertia uncertainties, external disturbances, actuator saturations, and faults. A nonsingular fixed-time sliding mode surface is constructed so that the settling time of the established surface is independent of the system initial states. By employing an exponential function in the controller design, an adaptive fixed-time control scheme is proposed to shorten the time during which the system states reach the sliding mode surface. With the proposed control method, the information on the bound of the lumped uncertainty is not needed in prior but estimated by the designed update laws. The fixed-time convergence of both the attitude and angular velocity is established, and comparative simulations are presented to illustrate the effectiveness of the proposed control scheme.

Adaptive Nonsingular Fixed-Time Attitude Stabilization of Uncertain Spacecraft