Tracking control of soft dielectric elastomer actuator based on nonlinear PID controller

Abstract

Soft dielectric elastomer actuators (SDEAs) have manifested tremendous potentials in the field of soft robots. However, the tracking control of the SDEA still confronts enormous challenges because of its complicated nonlinear characteristics. In this paper, a nonlinear proportional-integral-derivative (NPID) controller is devised to fulfil the tracking control of the SDEA. A dynamic model of the SDEA is established, and then applied to construct a simulation system to coarsely tune the parameters of the NPID controller based on the iterative optimisation algorithm. Subsequently, according to the results of the coarse tuning, the parameters of the NPID controller are finely tuned in practical experiments. Finally, the NPID controller of the SDEA is proved to be effective via several tracking control experiments with different reference trajectories.

Keywords:

• Soft dielectric elastomer actuator
• nonlinear characteristic
• dynamic model
• nonlinear PID controller
• iterative optimisation algorithm

Disclosure statement

No potential competing interest was reported by the authors.

Data availability statement

The data that support the findings of this study are available from the corresponding author, Wang, Y. W., upon reasonable request.

Additional information

Funding

This work was supported by the Young Scientists Fund of National Natural Science Foundation of China under Grant 61903344, the Hubei Provincial Natural Science Foundation of China under Grant 2015CFA010, and the 111 project under Grant B17040.