Autonomous systems often use feedback from an imaging system for guidance, navigation, and control. Such feedback requires an image processing method that yields an inherent delay in state measurements. For some camera-to-hand applications, the image-based sensing and control computations may be computed by a more capable processor and then be transmitted to a sensorless vehicle, resulting in a delay in control execution. To account for these delays, an approach is developed in this paper that applies a transformation, to separate the image coordinates into spatial and time domain components. This transformation, along with a novel integral error system, allows for the development of a robust controller that compensates for uncertain time-varying state delays and known time-varying input delays for nonlinear image dynamics. A Lyapunov-based stability analysis is used to prove that the developed controller enables a sensorless autonomous vehicle to yield uniformly ultimately bounded (UUB) tracking of a desired image trajectory.
['I. Chakraborty', 'Serhat Obuz', 'Warren E. Dixon']
Image-based tracking control in the presence of time-varying input and state delays