Robust attitude stabilization of spacecraft under constrained network with hysteresis quantizer

This article investigates the application of hysteresis quantizer for the spacecraft regulation problem under a constrained network. The hysteresis quantizer helps in quantizing the continuous control command at a lower rate of communication while avoiding the chattering in the quantized signal. The proposed scheme employs robust adaptive control law along with a filter error similar to the terminal sliding surface. Two separate adaptive laws are implemented to avoid the overestimation problem. The filter error is specially designed owing to the fact that the quaternion-based attitude representation faces the problem of unwinding. The theoretical analysis of the proposed scheme guarantees the uniformly ultimately bounded (UUB) stability of the closed-loop system, which is subjected to the quantization error, inertial uncertainties, and external disturbances. Moreover, it is also proved that the unwinding problem does not arrive in the proposed strategy. The validation of theoretical results is tested through extensive numerical simulation. Furthermore, the comparative analysis with the existing results shows the efficacy of the proposed approach.