a rigid structure configured to be attached with an object to be detected and be deformed with deformation of the object to be detected, the rigid structure comprises a plurality of rigid blocks arranged at intervals along a X axis and a plurality of strain amplifying regions, wherein one strain amplifying region of the plurality of strain amplifying regions is formed between every two adjacent rigid blocks of the plurality of rigid blocks, and the rigid structure has four mounting surfaces;

a detection circuit which comprises a first bridge circuit constituted by connecting at least four force sensors, wherein two groups of opposite bridge arms in the first bridge circuit are respectively arranged on two opposite mounting surfaces of the four mounting surfaces, and two force sensors are respectively arranged on two opposite mounting surfaces of the strain amplifying region; and

a signal generating circuit configured to cooperate with the detection circuit so as to generate different output signals when the rigid structure is stressed and deformed, wherein the detection circuit and the signal generating circuit are electrically connected with a signal processing circuit to recognize a direction and a magnitude of an acting force.