Twin-head six-axis force sensors

Three-axis force sensors based on the principle of a pressure pick-up device are characterized by their manufacturability, simple structure, and small size. Their use, however, has not been explored due to the incomplete force information that they provide. This paper proposes a new six-axis force sensor, composed of two three-axis force sensors and a connector, called a twin-head type six-axis force sensor (TH force sensor for short). The author first describes the theoretical basis for the operation of TH force sensors and provides the characteristic matrix connecting the load and sensor output vectors. While twenty-one types of TH force sensor are theoretically conceivable, the author proves that ten types can result in a characteristic matrix with a full rank. The author also considers an optimal design in the sense of minimum condition number.