Control system design for docking actuator

Research on the control system design for actuators used in a space docking system is presented. The phase of velocity matching and that of attenuation in the soft docking process are investigated by utilizing an experimental docking test facility which includes an electromechanical actuator and an air-lifted docking target. In the matching phase, the actuator is accelerated to match the velocity of the approaching target. A design of feedback control is shown for this phase, making use of the Kalman filter to obtain target speed estimation from the relative distance observation. In the attenuation phase, the actuator is decelerated to attenuate the kinetic energy of the target. The most effective way of attenuation is considered to be constant acceleration attenuation. A control method is presented to attain this type of attenuation. Another method is applied to design a compliance control strategy which adjusts the actuator force for different kinetic energies to the docking target