Research On A Stick-Slip-Driven Micro-Manipulation System

Long-ranged precise positioning technique is of great importance to micro- and nanomanipulation. Stick-slip-driven system has advantages of simple structure and simple control signal(saw-tooth shape), which is necessary in engineering applications. In this dissertation, a stick- slip-driven system including a compliant mechanism, is designed. The research’s purpose is to improve the driving performance of this system.It is known that stick-slip actuation is affected by factors such as the driving waveform, the dynamics of the driving mechanism, the friction of the contact surface and so on. For the purpose of analyzing these factors quantitatively, the dynamic model of the system is given. Second-order dynamic model and Lu Gre tribology model are employed to represent the driving mechanism and the friction of the contact surface respectively. An expression between the allowable values of the driving waveform parameters and the pre-tighten force of the piezoelectric actuator is presented.In the stick-slip actuation process, the parasitic vibration after the slip phase is a major issue affecting the driving performance. Open-looped feed-forward control methods including notch filter and input shaping are considered to optimize the driving waveform so as to reduce the vibration. After plotting the parasitic vibration ratio curves and rising time ratio curves, we find that both methods are capable.The system is numerical simulated to analyze the stick-slip actuation process. A test stand is also set up to carry out experiments. The influences that the system parameters have on the driving speed, as well as the comparison of the vibration suppression effect between the two control methods are evaluated via simulation. Both the simulation analysis and the experimental results validate the effectiveness of the optimized driving waveform and the improvement of the driving performance of the system. It is experimental shown that the resonance phenomenon weaken the efficiency of the stick-slip actuation.