Publications (2)0 Total impact
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Conference Proceeding: Daisy Chaining Based Visual Servo Control Part I: Adaptive Quaternion-Based Tracking Control
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ABSTRACT: A quaternion-based visual servo tracking controller for a moving six degrees of freedom object is developed based on image feedback from a moving camera. The control objective is for the object to track a desired trajectory determined by a sequence of prerecorded images from a stationary camera. To achieve this result, several technical issues were resolved including: discriminating the relative velocity between the moving camera and the moving object, compensating for the unknown time-varying distance measurement from the camera to the object, relating the unknown attitude of the control object to some measurable signals, and using unit quaternion to formulate the rotation motion and rotation error system. By utilizing multi-view image geometry to develop homography relationships between the moving camera frame and the moving planar patch coordinate systems, the relative velocity issue is resolved. By using the depth ratios obtained from the homography decomposition, the unknown depth information is related to an unknown constant that can be compensated for by a Lyapunov-based adaptive update law. Lyapunov-based methods are provided to prove the adaptive asymptotic tracking result.Control Applications, 2007. CCA 2007. IEEE International Conference on; 11/2007 -
Conference Proceeding: Daisy Chaining Based Visual Servo Control Part II: Extensions, Applications and Open Problems
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ABSTRACT: In this paper, the open problems and applications of a daisy chaining visual servo control strategy are given. This paper is Part II of Hu et al. (2007) in which a tracking problem using the daisy chaining strategy is addressed. The main idea of the daisy chaining strategy is to use multi-view geometry to relate coordinate frames attached to the moving camera, moving planar patch, and the desired planar patch specified by an a priori image. Geometric constructs developed for traditional camera-in-hand problems are fused with fixed-camera geometry to develop a set of Euclidean homographies. Based on the homographies, the corresponding rotation and translation components can be extracted for use in the control development. Different from the traditional camera-to-hand and camera-in-hand visual servo control configurations, two cameras are used to construct the homography relationships and estimate the pose of an object modeled as a planar patch (e.g., an unmanned ground vehicle (UGV) or an unmanned air vehicle (UAV)) when in case the object is out of the field of view (FOV), or when the current and desired poses of the object are within the FOV of a single camera.Control Applications, 2007. CCA 2007. IEEE International Conference on; 11/2007
