Development and application of flexible pneumatic cylinder with linear encoder

The wearable actuator needs to be flexible so as not to injure the human body. We aim to develop a flexible and lightweight actuator which can be safe enough to be attached to the human body. We have proposed new types of flexible pneumatic actuators that can be used even if the actuator is deformed by external forces. We also tested a robot arm using the tested flexible pneumatic cylinders. In the next step, the actuator should be able to measure its displacement to realize the higher control performance. The purpose of this study is to develop the displacement sensor for the flexible actuator and to combine it with the actuator. In this paper, we develop a flexible linear encoder that can measure the displacement of the flexible pneumatic cylinder using four photo-reflectors. They can detect the state of bending tube to compensate the sensor output even if the tube is bent. In addition, we develop a flexible pneumatic cylinder with a built-in linear encoder. As a result, we confirm that the tested cylinder can be realized even if the cylinder tube is affected by the disturbance while driving.