On-vehicle visual tracker with disturbance rejection

Abstract

This paper presents the synthesis and implementation of a passivity based controller designed for visual tracking of moving objects in a disturbance rejection scheme. The purpose of this application is to control the line of sight of a 2-DOF sensor platform in a moving coordinate frame, when the movement of the vehicle carrying the platform acts as a disturbance of finite energy. External torques due to vehicle movement downgrade the visual tracking performance and can cause instability and total loss of sight of the objective. These disturbances can be compensated for in an effectively manner introducing a classical L2-gain disturbance rejection scheme, widely deployed in inertial frame robotic systems. The proposed controller has been tested in a real 2-DOF platform mounted on a moving testbench that emulates different types of non-inertial vehicle surfaces.