A Self-Sensing Approach for Dielectric Elastomer Actuators Based on Online Estimation Algorithms

• Published in: IEEE/ASME transactions on mechatronics Vol. 22; no. 2; pp. 728 - 738
• Main Authors: Rizzello, Gianluca, Naso, David, York, Alexander, Seelecke, Stefan
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.04.2017; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Actuation; Actuators; Algorithms; Capacitance; Current measurement; Dielectric elastomer (DE); dielectric electroactive polymer; Elastomers; Electric potential; Electrodes; Field programmable gate arrays; Mathematical model; Position sensing; Resistance; self-sensing; smart materials; Voltage; Voltage measurement
• ISSN: 1083-4435; 1941-014X
• DOI: 10.1109/TMECH.2016.2638638

This paper develops a position self-sensing approach for a motion actuator based on a dielectric elastomer membrane. The proposed method uses voltage and current measurements to estimate the electrical resistance and capacitance online by means of a high-frequency low-amplitude voltage component injected in the actuation signal. The actual deformation is subsequently reconstructed using a model-based estimate of the electrical parameters implemented on a field programmable gate array platform (FPGA) with a sampling frequency of 20 kHz. The main peculiarity of the approach is the use of recursive identification and filtering algorithms that avoid the need of charge measurements. The self-sensing algorithm is extensively validated on a precision linear-motion actuator, which uses a nonlinear biasing system to obtain large actuation strokes.