Visual servoing path-planning for approaching cylindrical objects

Eye-in-hand systems have received significant attention for the task of approaching an object identified by its reference image shown in advance. Image based visual servoing (VS) methods demonstrate robustness to image noises, but encounter difficulties especially when camera displacement is large. More challenges exist when the object is cylindrical with less texture. This paper proposes new feature set and pertinent trajectory planning scheme to achieve a convergent path with tolerable violation of camera field of view (FOV) limits, allowing transient loss of part of the observed object. Specifically, new features and interaction matrices are developed to achieve global convergence. Feature trajectories are then planned with tolerable FOV violation through a constrained nonlinear minimization path-planning technique. They are later tracked via an adapted IBVS controller in a switching manner. Simulation with two views of a real drinking vessel validates the proposed method and demonstrates its adaption to partial FOV violation.