Title :
Range identification for perspective vision systems
Author :
Dixon, W.E. ; Fang, Y. ; Dawson, D.M. ; Flynn, T.J.
Author_Institution :
Eng. Sci. & Technol. Div.Robotics, Oak Ridge Nat. Labs., TN, USA
Abstract :
In this note, a new observer is developed to determine range information (and, hence, the three-dimensional (3-D) coordinates) of an object feature moving with affine motion dynamics (or the more general Ricatti motion dynamics) with known motion parameters. The unmeasurable range information is determined from a single camera provided an observability condition is satisfied that has physical significance. To develop the observer, the perspective system is expressed in terms of the nonlinear feature dynamics. The structure of the proposed observer is inspired by recent disturbance observer results. The proposed technique facilitates a Lyapunov-based analysis that is less complex than the sliding-mode based analysis derived for recent observer designs. The analysis demonstrates that the 3-D task-space coordinates of the feature point can be asymptotically identified. Simulation results are provided that illustrate the performance of the observer in the presence of noise.
Keywords :
Lyapunov methods; Riccati equations; cameras; computer vision; image motion analysis; nonlinear systems; observers; 3D task-space coordinates; Lyapunov-based analysis; Ricatti motion dynamics; affine system; camera; motion parameters; nonlinear feature dynamics; nonlinear observer; object feature determination; observability condition; perspective vision system; range identification; visual servoing; Australia; Control systems; Controllability; Machine vision; Nonlinear dynamical systems; Observability; Optimal control; Publishing; System testing; Time varying systems;
Journal_Title :
Automatic Control, IEEE Transactions on
DOI :
10.1109/TAC.2003.820151