Improvements on an autonomous robot prototype

Abstract

Autonomous robots may be understood as vehicles carrying electronic devices and sensors in order to be capable of receiving instructions from a central unit, processing them and performing the desired task, although intermittently supervised and updated by the central unit. This concept is applied to the present work, where a two-wheeled mobile robot executes trajectories composed of specified arcs of circumferences monitored only by the angular displacement of the motors, permitting closed loop control of these. Based on rigid body mechanics, it was possible to describe the motion of the vehicle in terms of the angular displacement of the motors. Although a tracking problem, the parameters of the controllers of the two motors were determined considering the problem as a step input regulation one. Improvements introduced on a previous simpler version of the autonomous robot are described. These improvements consisted of adding to the vehicle’s control software the capacity to follow a generalized trajectory, composed of a succession of fixed simple trajectories. For this purpose it was necessary to alter the software structure. The parameters for all successive trajectories are transmitted from a computer to the vehicle. Future improvements are possible, such as including a radio link to allow on-line trajectory updating and including environmental sensors to aid vehicle guidance.