Friction Torque Testing System Based On Torque Motor

This research is based on a practical engineering project funded by China Aerospace Science and Technology Corporation (CASC). In this thesis, the friction torque testing system based on torque motor is studied. The testing system consists of a drive motor, providing steady output, and a tested transimission gear, serving as the friction load to offer the friction torque. To ensure the stability of drive motor’s output, compensation strategy of its friction torque is investigated. Thereafter, the friction torque testing system is designed and built up.Firstly, literature review of friction torque testing technology is carried out, mainly aiming at the motor friction torque testing system. Due to the large dispersion of friction torque, it is necessary to design a stable, low vibration and high precision drive system. So, the key question of this system is to propose an appropriate control strategy for the driving motor. In this paper, the mathematical model of permanent magnet synchronous motor drive system is established. Based on the established model, simulation and analysis of the permanent magnet synchronous motor under vector control of motor velocity and armature current output characteristics are implemented.In order to solve the vibration problem caused by the friction torque, the wave torque and the dead zone of the measurement system and the feedback system while the motor operates at low speed. This thesis mainly proposes a model-based adaptive control strategy to compensate the friction torque in the drive motor. Then, the adaptive law of the system under the proposed control strategy is analyzed and calculated. The simulation result shows that the control strategy significantly improves the performance of the whole system.Finally, a practical test rig is designed and set up to verify the effectiveness and feasibility of the control strategy and the validity of the model. The experimental results vividly indicates that the design of the adaptive law is reasonable and the friction compensation can restrain the vibration of the motor at low speed, which can meet the design requirements of the system.