Development of a target recognition and following system for a field robot

Abstract

The objective of this study was to develop a target recognition and following system for a field robot. The platform used in this study was an electric vehicle that had been modified into an automatic vehicle. A 3D camera was attached in the front of the vehicle to deliver depth and grayscale information on the environment. The degrees of correspondence between objects present in consecutive frames were calculated using their spatial descriptors and grayscale features. A correspondence assigner was designed to recognize the same objects in consecutive frames, and their locations could be acquired at the same time. Based on a pursuit strategy, an appropriate steering angle was calculated for the robot vehicle to move towards the target. A PID controller was used to determine appropriate vehicle speed for maintaining a certain distance from the target. Field tests were conducted to evaluate robustness and performance of the system. Results showed that the robot vehicle was correctly and effectively guided to follow the target while preventing collisions with disturbances. RMS errors were 1.0m and 1.3° in terms of space and deflection angle, respectively, when following a target that moved in a straight line at an average speed of 1.1m/s.