This paper describes a hammering robot with a flexible link which can hit an object from an arbitrary direction in a 3-D space. A dynamical equation of a flexible link hammer is presented by taking gravity into consideration. The conditions that the hammer can strike an object flatwise with only a normal velocity to its face are investigated, and a manipulating method to satisfy the hitting conditions is obtained.

This paper proposes a continuous hitting operation on objects with unknown coefficients of rebound by a flexible link hammer. This hammer system uses only the first mode of vibration for a desired hitting. The angular acceleration for a continuous hitting can be obtained from numerical calculations. However, this method is not useful for on-line processing Therefore, the multi-layered neural networks are applied to the calculation of the parameters of the angular acceleration. The outputs of the trained network agree well with the numerical solutions.

The paper deals with the motion control of a flexible link hammer within a vertical plane. The deflection of the flexible link hammer is analyzed in the condition that the hub actuator is excited by a single pulse acceleration and the head is subjected to gravity, Next, the flexible link hammer is attached to the end effector of a home robot. It is shown that the robot can tap a person on the shoulders to relieve them from stiff shoulders.