New results in visual invariant features for improved image based visual servoing

Features selection plays an important role in image based visual servoing, the objective is to determine six independent visual features with nice decoupled and linear properties. Visual invariant is well-known as an ideal kind of features to design an improved IBVS. In this paper, a kind of visual invariant to rotational motions is derived from projection onto surface of a unit sphere, and it is calculated by vector inner product operation. Invariant based feature jacobian can be provided through a simple deduction with operation laws of vector or matrix. Then, six independent visual features are determined with three inner product features and homography-based features, and a decoupled IBVS controller is proposed. Finally, simulations results with a free-flying perspective camera are provided to illustrate the significance of our proposed method.