Abstract
This paper considers a method of estimating a contact point between a robot hand and an object by using a force sensor with measurement noise. The estimation problem is formulated as a problem of nonlinear constraint optimization, in which the cost function represents the estimation error against the measurement noise and the constraints require the contact point being on the fingertip surface and the fingertip force directing inward. Although problems of nonlinear constraint optimization can be only solved by numerical optimization in general, it is shown that the optimization problem for the estimation can be solved analytically in this case. Experimental results are shown to prove the efficiency of the proposed method.