Research Of Control Technology On Electro-mechanical Actuator Used In Space Docking System

As a key actuating mechanism of soft space docking system, the linear electro mechanic actuator isrequired to have high positioning precision, wide speed range, quick dynamic response and highreliability because of the complexity of space docking. In order to meet the high performancerequirements of linear electro mechanic actuator, digital servo controller based on high-performanceDSP is used in the system. The control strategy of linear electro mechanic actuator is going to beresearched and the software of the control system is going to be designed in this paper. The mainresearch contents of the paper are listed as follows:(1) The simulation model of electro mechanic actuator control system is built and the controllers ofcurrent loop, speed loop and position loop are designed and their parameters are corrected. Frequencyresponse characteristics of all feedback loops are analyzed.(2) The overall software structure and interrupt service subroutines of electro mechanic actuatorcontrol system are designed. The MODBUS communication protocol is used to realize thecommunication between the control system and upper computer observing software. The applicationsof velocity measuring methods and modified digital PID controllers are realized in the system. Themain technical specifications of electro mechanic actuator control system are verified by experiments.(3) The vibration problem of transmission system in linear electro mechanic actuator is analyzed.The model-based velocity difference compensating method for vibration suppression is proposed andverified in Matlab/simulink simulation environment. The multi-mass torsional transmissionexperimental setup is built and the experimental effect of the proposed compensating method isverified.(4) The application of fuzzy PID controller in the linear electro mechanic actuator is researched. Afuzzy PID controller applied in brushless DC motor is designed and verified in Matlab/simulinksimulation model. A fuzzy I+P controller applied in model-based velocity difference compensatingmethod for vibration suppression is designed and verified in both simulation model and experimentalsetup.