Experimental verification of estimated parameters of contact conditions by active force sensing

To accomplish assembly tasks by using robots, contact conditions must be identified and controlled during performing the tasks. This paper proposes parameter identification of contact conditions between a grasped object and its environment, and derives uncertainty of the estimated parameters. The contact conditions include contact type, contact position, and contact direction. Four contact types as point, soft-finger, line, and planar contact types are distinguished by active force sensing. We formulate a least-squares function including contact position, and contact direction. The uncertainty of the estimates is derived by using an amount of the function. Effectiveness of our proposed method is demonstrated by experiments.