Elastic prescribed control for spacecraft via dynamic coded event-triggered scheme

This study focuses on the attitude control of spacecraft subject to actuator faults, disturbances, and uncertainties. Traditional prescribed performance control tends to suffer from control singularities caused by saturation under faults and diverse initial conditions, limiting its applicability in practical scenarios. To overcome these challenges, Elastic Prescribed Control (EPC) is proposed in this study firstly, which introduces a novel appointed-time performance function that allows elastic adjustment of performance boundaries. EPC effectively mitigates control singularities caused by faults and unknown initial conditions through elastic and initial capture mechanisms, enhancing system robustness and reducing conservatism. Furthermore, an improved Dynamic Coded Event-triggered Scheme (DCES) is proposed, featuring adaptive dynamic coding that adjusts the number of encoding bits based on performance demands and communication resource usage. This significantly reduces communication frequency and bit consumption while preserving performance. Finally, simulations validate the effectiveness of the proposed method in constraining tracking errors to the desired range under arbitrary initial conditions, ensuring the expected elastic prescribed performance, and reducing communication resource consumption.