A New Implementation Scheme in Robotic Vehicle Propulsion Using Brushless DC Motor

This paper deals with the development of a propulsion system for a robotic vehicle using a permanent magnet Brushless DC (BLDC) motor with sensorless commutated drive. The proposed vehicle has four BLDC motor driven wheels, each having separate sensorless drive circuitry but all controlled by a single supervisory controller. The vehicle is capable of performing angular and linear displacements, ruled by a distantly located operator. A drive/break by-wire technology is utilized for operation of the wheels. In this work, a real time system with sensorless commutation is designed and implemented that utilizes a three phase inverter, a microcontroller and a motor speed feedback as drive circuitry. A suitable cost effective algorithm has also been developed to generate an appropriate six transistor switching sequence to commute the BLDC motor. The characteristics of the implemented drive give satisfactory outputs over a wide range of controlled speed variation from 330 to 2440 rpm. The effectiveness of the system so designed is demonstrated through the real time experimental data.