Singularity-Avoidance Prescribed Performance Attitude Tracking of Spacecraft

TL;DR

This paper introduces a novel control scheme for spacecraft attitude tracking that avoids singularities and over-control issues, ensuring robust and precise performance through innovative error transformation and adaptive constraints.

Contribution

It proposes a Singularity-Avoidance Prescribed Performance Control scheme with a shear mapping-based error transformation and a time-varying constraint boundary for improved spacecraft attitude control.

Findings

The proposed SAPPC scheme effectively avoids singularities.

It reduces over-control near constraint boundaries.

Numerical simulations confirm robustness and accuracy.

Abstract

The attitude tracking problem with preassigned performance requirements has earned tremendous interest in recent years, and the Prescribed Performance Control (PPC) scheme is often adopted to tackle this problem. Nevertheless, traditional PPC schemes have inherent problems, which the solution still lacks, such as the singularity problem when the state constraint is violated and the potential over-control problem when the state trajectory approaches the constraint boundary. This paper proposes a Singularity-Avoidance Prescribed Performance Control scheme (SAPPC) to deal with these problems. A novel shear mapping-based error transformation is proposed to provide a globally non-singular error transformation procedure, while a time-varying constraint boundary is employed to exert appropriate constraint strength at different control stages, alleviating the potential instability caused by the over-control problem. Besides, a novel piece-wise reference performance function (RPF) is constructed to provide a relevant reference trajectory for the state responding signals, allowing precise control of the system's responding behavior. Based on the proposed SAPPC scheme, a backstepping controller is developed, with the predefined-time stability technique and the dynamic surface control technique employed to enhance the controller's robustness and performance. Finally, theoretical analysis and numerical simulation results are presented to validate the proposed control scheme's effectiveness and robustness.