Vision based autonomous path tracking of a mobile robot using fuzzy logic

In this paper we present an algorithm for autonomous path tracking of a mobile robot to track straight and curved paths traced in the environment. The algorithm uses a fuzzy logic based approach for path tracking so that human driving behavior can be emulated in the mobile robot. The method combines a fuzzy steering controller, which controls the steering angle of the mobile robot for path tracking, and fuzzy velocity controller which controls the forward linear velocity of the mobile robot for safe path tracking. The inputs to the fuzzy system are given by the vision system of the mobile robot. A camera is used to capture images of the path ahead of the mobile robot and the vision system determines the lateral offset, heading error and the curvature of the path. We perform experiments using a mobile robot platform. In the first experiment the mobile robot is able to successfully track a straight path. This shows the effectiveness of the fuzzy steering controller. We also perform experiments on paths containing curved sections. The fuzzy velocity controller was able to command appropriate speed for safe tracking of the path ahead of the robot. The effectiveness of the fuzzy velocity controller is shown in this experiment.

I. Introduction

In the area of mobile robot navigation, there exists many problems that robotics researchers have addressed using different techniques. One such problem is the path tracking problem where the mobile robot navigates by following a path traced on the ground in the robot environment. Path tracking problem is most relevant to mobile robots in industrial and manufacturing environment as well as to mobile robots in agriculture applications [1].