Implementation of a Decoupled Digital Feedback Control Architecture on an Arduino - Free RTOS Real-Time Embedded System for Input Delay Robotic Servomechanisms

Abstract

This paper presents an experimental study on a real-time embedded system of a decoupled PIDF (Proportional Integral, Derivative with Filter) digital control architecture for robotic input delay servomechanisms. The test bench includes an Arduino Uno board integrating a specific microcontroller, a robot arm with four degrees of freedom and DC servo motor seals, a Free RTOS preemptive scheduler for pseudo parallelism of tasks and a console ensuring interactivity with the user. The choice of decoupled digital control parameters in terms of proportional, integral, derivative with filter and sampling time gains has been based on the controller tuning techniques available in the literature for SISO (Single-Input Single-Output) input delay servomechanisms. The prototype implanted in the card occupies 26% of the storage space and 18.80% of the dynamic memory. The results show the attached robotic servomechanisms that converge quickly and as precisely as possible to the desired values of joint variables. Regardless of the non-linear effects on the robot arm, especially the input delay, strict tracking of the trajectory is observed. This demonstrates the high precision of the proposed decoupled control architecture. The different positions of the robotic servo system have been represented in Cartesian space using MATLAB 2019-Ra software. They have been listed using the geometric model of the robot arm.