Attitude control of reentry vehicles in roll channel using single-gimbal control moment gyros and a reaction control system

A novel roll-channel attitude control scheme using a combination of single-gimbal control moment gyros and a reaction control system is proposed, providing sufficient control torque during the whole reentry process. A scissored-pair configuration is applied to the single-gimbal control moment gyros, which guarantees control torque exclusively along the roll axis and avoids internal singularity. A sliding-mode attitude controller is proposed to meet the requirements of roll-channel attitude stability and disturbance rejection. To obtain an optimal allocation of the commanded torque to the single-gimbal control moment gyros and the reaction control system, an allocation method based on fuzzy reasoning is proposed. To render the design and validation of the control scheme close to reality, the responsiveness of the single-gimbal control moment gyro is considered, and the discrete and delay properties of the reaction control system are included. The steering logic of the single-gimbal control moment gyro and the modulator of the reaction control system are designed, respectively. Numerical simulation is performed to verify the proposed control scheme. Moreover, a hardware-in-the-loop simulation system based on an air-bearing test bed is developed to conduct experiments for convincingly validating the proposed attitude control method. The feasibility and good performance of the proposed control scheme are verified by the results of the numerical simulation and the experiment.