KEYWORDS: Microrobot, piezoelectric actuator, active force control, iterative learning algorithm, in-pipe application
ABSTRACT: In this paper, a piezoelectric microrobot is modelled and simulated based on active force control (AFC) with a proportional (P) – type iterative learning algorithm (ILA) operating in a constrained environment for an in-pipe application. A mathematical model that represents the dynamic characteristics of microrobot has been developed considering the robot system subjected to different input excitations. The movement of the robot is based on an impact drive mechanism (IDM) strategy which causes the robot to move in a worm-like manner in the pipe. A dedicated feedback controller is integrated into this system that incorporates proportional-integral-derivative (PID) controller and active force control (AFC) with an embedded ILA. The primary objective of the scheme is to ensure a robust and accurate trajectory tracking control of the microrobot system is achieved. The performance of the proposed control system under different types of disturbances is evaluated through a rigorous simulation study. The obtained results clearly demonstrate an effective trajectory tracking capability of the worm-like microrobot in spite of the negative effects of the external disturbance conditions.
