Zhang Jiyang

A novel suspended method based on flux density feedback for AMB system without position sensors

A novel suspended method based on flux density feedback for AMB system without position sensors is presented in this paper. Ultra-thin Hall sensor is a part of the flux density feedback control with the function of detecting the flux density. According to the model of AMB rotor, position control-loop is realized with rotor position resolved from magnetic flux density and winding current. Flux density feedback control eliminates the model error caused by the inconsistencies between sensor target and AMB. With the novel approach, position sensors and detection target are not required; besides, size and weight of AMB system are reduced. It is of great benefit to miniaturization and integration for the space AMB system.

Research on high accuracy, long life, and high reliability technique of control moment gyroscope

The control moment gyroscope (CMG), which has the capability to produce large, continuously adjustable torques, is a key attitude control actuator for a spacecraft. The rotor spins at a constant rate about the rotor axis. Any rotation of the gimbal causes a change in the angular momentum of the spacecraft, which produces the gyroscopic moment for attitude control. On September, 2011, 200Nms CMGs were carried in orbit onboard Tiangong target spacecraft of China, which was the first inorbit application of independently developed CMG of China. 200Nms CMGs are designed for the attitude control of middle size spacecraft. Since then, even larger CMGs were under development to meet the demand of the attitude control for even larger spacecraft, such as the space station of China. In this research, three techniques are developed: System redundancy technique, for all electrical components and control electronics; Long life flywheel shafting lubrication technique, with screw cap shaped oil reservoir for 15 years long life lubrication; High stiffness gimbal drive and high accurate control technology, with harmonic reducer, and disturbance observer based terminal sliding mode control. The prototype of 1000Nms CMG was developed, and has successfully passed the qualification level environmental test.