Basic Performance of Bellows Actuator and its Application to a Force Sensor.

In this paper, we design a new pneumatic actuator using welded metal bellows. Since this actuator has no slide parts, there is no influence of friction forces. Therefore, it is expected that the actuator has good control performance for positioning and generating exact desired forces. First, we propose a positioning control law for the bellows actuator in which position and pressure of the bellows are controlled independently by dividing the control loop into two stages. It is experimentally shown that fine positioning can be easily obtained by the proposed control law. Furthermore pressure control performance is revealed through experimental results. Second, in order to use the bellows actuator as a force sensor (bellows sensor), we investigate the static and dynamic characteristics of the bellows actuator. From the experimental results, the capability of the bellows sensor becomes clear. Finally, the bellows actuator is applied to a sensing actuator and the effectiveness of the actuator is demons-trated through several experimental results.