Self-adaptive knee joint exoskeleton device

The invention discloses a self-adaption knee joint exoskeleton device. The device comprises a thigh supporting piece matched with the thigh of a human body, a shank supporting piece matched with the shank of the human body and a knee joint body arranged between the thigh supporting piece and the shank supporting piece. The knee joint body comprises a five-rod mechanism used for being self-adaptive to the rotation center of the knee joint of the human body, a knee joint driver used for driving the five-rod mechanism to conduct self-adaptive work and a variable stiffness driver used for bearing force. According to the device, the combination of the five-rod mechanism and the variable-stiffness driver is adopted, the device is matched with the left leg and the right leg of a person, and in the three actions of walking, squatting and standing up of the person, the output of the knee joint driver and the variable-stiffness driver is controlled so as to adapt to knee joint motion states in the three states, and the