In this paper, an assembly wirst is developed for robotic assembly using piezoelectric actuators. In the assembly task, the developed wrist can compensate the position error, between high precision parts to be assembled, at the early stage of an insertion process. Because it can get very fine positioning up to submicron. Futhermore, a mechanical amplifier is designed in order to amplify the small displacement generated from piezoelectric actuators. Since the characteristics of the mechanical amplifier are critical to wrist performance, such as the amplification ratio and time response, they are investigated through a series of simulations and experiments. In addition, a series of insertion experiments are performed to evaluate the assembly performance of the developed wrist by using vibratory method. The experimental results show that the developed wrist can quickly compensate positioning errors between parts even if the compensated range is rather small. A further study is to develop the more effective wrist so that it can compensate for large positioning errors, which mainly results from the effectiveness of the mechanical amplifier of the wrist.
