The coupling analysis for the gimbal servo system of a control moment gyroscope considering the influence of a flexible vibration isolator.

To reduce the influence of vibrations generated by the control moment gyroscopes (CMGs), the researchers have put a lot of effort into isolating the vibration between the CMG and the satellite in order to lessen the impact of vibrations produced by the CMGs. The flexibility of the isolator causes the extra degrees of motion for the CMG, which is coupled with the CMG's dynamic behavior and the control performance of the gimbal servo system is therefore changed. However, how the flexible isolator influences the performance of the gimbal controller is uncertain.

A double gimbal optical image stabilizer driven by piezoelectric stacks.

With the advantages of high accuracy and fast response, piezoelectric actuators are used to drive optical image stabilizers. As a piezoelectric stack is not tensile, preload voltage is required for a traditional piezoelectric driven optical image stabilizer, which wastes electricity and adversely affects the stack's performance. In this paper, we propose a double gimbal optical image stabilizer, whereupon a prototype is machined and its performance is assessed.

Research on ultra-low speed driving method of traveling wave ultrasonic motor for CMG.

The single-gimbal of control moment gyro (SGCMG) servo system needs high stability, high precision and low speed operation. Therefore, a novel driving approach of ultrasonic motor, called the superposition pulse driving method, is proposed in the present study by prolonging the turn-off time of the conventional micro-stepping driving method. Then, three types of contact models are proposed with the variable of pre-pressure between stator and rotor.

A continuously variable beam expander driven by ultrasonic motors.

A dynamic beam shaping system requires a variable beam expander. Three optical lenses form the core of the proposed beam expander, and two hollow ultrasonic motors are used to adjust the positions of two of the lenses. A polymer-based stator is introduced in the ultrasonic motors to decrease their weight, whereupon a prototype is machined and its performance is assessed.