Control of pneumatic actuator in consideration of hysteresis characteristics

Recently, robots not only have been researched and developed actively but also have replaced humans in several fields such as medical treatment and nursing. For robots to coexist with humans and provide support, they must have human-like dexterity and should be very safe. Therefore, pneumatic actuators are used to develop safe and lightweight robot hands. However, the relationship between the internal pressure and contraction ratio of pneumatic actuators is nonlinear, with a hysteresis characteristic and a dead zone. Moreover, the nonlinear characteristics of pneumatic actuators change with the applied load. In this study, we proposed a hysteresis model that can express the change in these hysteresis characteristics, and we constructed a control system that integrated this hysteresis compensation by using the proposed hysteresis model.