Optimal Feedback Linearization Control for a Bioinspired Soft Pneumatic Contractive Actuator

The soft pneumatic actuation is considered one of the most practical actuation systems in bioinspired applications, where the supplied air inflates expandable channels embedded in soft materials and causes desired movements. As the number of soft actuation applications increases, the control of soft pneumatic actuators becomes more important. This paper discusses the design and implementation of the feedback linearization control for a soft ring actuator called RiSPA. RiSPA is a bellows-driven, elastomer-based actuator that was developed to reproduce motility functions of the lower part of the stomach for a gastric simulator. The dynamics model for the RiSPA is highly nonlinear and time-varying. By applying feedback linearization, the RiSPA's dynamic model is converted into a linear time-invariant (LTI) system. Then, the linear quadratic regulator (as a linear optimal controller) is designed and applied on the new LTI model. The numerical simulation results show that the regulation performance is successfully conducted on the RiSPA model, and all the state variables have reached their desired values.