State Boundary Avoidance Control of Dielectric Elastomer Actuator for Material Safety Assurance

Dielectric Elastomer Actuators (DEAs) have been used in various applications in wearable assistive devices and energy harvesting systems. However, material safety assurance control, which prevents dielectric elastomer failures, is not fully investigated. In this work, a state boundary avoidance control of DEA for material safety assurance is developed. Since various DEA configurations share common failure modes, incorporating these modes into the system is crucial for extending DEA lifetime and improving robustness. To expand the DEA’s working range, the algorithm for internal safety control allows operation within a broader feasible region while preventing electrical breakdown (EB), electromechanical instability (EMI), loss of tension (LT), or rupture by stretch (RS). This algorithm prioritizes safety control when the feasible space is violated and allows primary control when operating within the safe space. Two case studies to validate the theory are discussed for reference tracking and energy harvesting. An algorithm for internal safety control in DEAs, considering both closed and open-loop control for reference tracking and energy harvesting, is proposed. The safety control algorithm can maximize energy harvesting output power without violating material safety rules, making it applicable to various energy source conversions like human motion, tidal wave, and wind energy.