Force control of a tri-layer conducting polymer actuator using optimized fuzzy logic control

Abstract

Conducting polymers actuators (CPAs) are potential candidates for replacing conventional actuators in various fields, such as robotics and biomedical engineering, due to their advantageous properties, which includes their low cost, light weight, low actuation voltage and biocompatibility. As these actuators are very suitable for use in micro-nano manipulation and in injection devices in which the magnitude of the force applied to the target is of crucial importance, the force generated by CPAs needs to be accurately controlled. In this paper, a fuzzy logic (FL) controller with a Mamdani inference system is designed to control the blocking force of a trilayer CPA with polypyrrole electrodes, which operates in air. The particle swarm optimization (PSO) method is employed to optimize the controller's membership function parameters and therefore enhance the performance of the FL controller. An adaptive neuro-fuzzy inference system model, which can capture the nonlinear dynamics of the actuator, is utilized in the optimization process. The optimized Mamdani FL controller is then implemented on the CPA experimentally, and its performance is compared with a non-optimized fuzzy controller as well as with those obtained from a conventional PID controller. The results presented indicate that the blocking force at the tip of the CPA can be effectively controlled by the optimized FL controller, which shows excellent transient and steady state characteristics but increases the control voltage compared to the non-optimized fuzzy controllers.

Force control of electro-active polymer actuators using model-free intelligent control

“…Besides controlling the tip displacement of bendertype CPAs, the blocking force generated by their freeend is required to be robustly and accurately controlled in applications such as micro-nano manipulation, cellinjection, etc. Although there are many works in the literature focusing on modeling and control the CPAs' tip displacement, there is a minimal number of works on the control of blocking force of such actuators (Coskun et al, 2017;Itik et al, 2014). Only quasi-static models (Alici andHuynh, 2006, 2007) are presented to predict the force output of the trilayer CPAs as modeling study which are not convenient to use in applications where the blocking force output of the CPAs needs to be controlled dynamically.…”

Variable Stiffness Actuators: Review on Design and Components

“…Recent research provides promising developments with different actuator principles, such as pneumatics [20], [21] or elastomeres [22]- [26]. This paper focuses on the electromechanical implementation of VSAs as the current state of the art promises to be advantageous in the combination of active bandwidth, output power, and positioning precision.…”