DEVELOPMENT OF DIRECTIONAL ALGORITHM FOR THREE- WHEEL OMNIDIRECTIONAL AUTONOMOUS MOBILE ROBOT

Abstract

An omnidirectional algorithm has been developed to control autonomous mobile robots with three wheels. The implementation system consists of three planet DC motors with a rated power of 80 W for three wheels, three encoders for speed feedback, one encoder for distance feedback, and one digital compass sensor for angle feedback. The main system with an STM32F407 microcontroller is designed for directional control of wheels based on the signal received from compass sensor and encoder, and then controls three subsystems to adjust the steering speed of each wheel. The subsystem is built to control only one DC motor for each wheel with the built-in proportional integral derivative controller (PID) algorithm by an STM32F103 microcontroller. Furthermore, the directional control algorithm is developed for three omnidirectional wheels and a PID algorithm is designed to control the speed of DC motor for each wheel. It can be seen from the results obtained that the proposed system has several advantages: (1) automatically adjusting the angle and position; (2) erasing the sensor for tracking line of the automobile robot; (3) being self-developed; (4) ensuring reliable accuracy.