Semi passive joint exoskeleton

A semi-passive knee exoskeleton assembly configured to provide assistance to a user when running/walking, the semi-passive knee exoskeleton assembly comprising:

• a thigh link associated with a thigh attachment configured to fit the user's thigh;
• a shank link associated with a shank attachment configured to fit the user's shank;
• an arm link pivotally articulated to the thigh link and to the shank link about a main knee shaft;
• a spring connected to the thigh link at one end thereof, and to the arm link at an opposing end thereof;
• a primary transmission carried within the arm link and being configured to control movement between the arm link and the shank link, the primary transmission comprising a primary clutch configured to be selectively engaged whereby the arm link pivots together with the shank link thereby engaging the shank link with the spring, and to be selectively disengaged whereby the arm link pivots independently of the shank link, the primary clutch comprising a primary motor configured to effect the engagement and disengagement;
• one or more sensors, configured to provide signals indicative of the user's running/walking cycle phase;
• and
• a controller configured to control, in real time, operation of the primary motor to engage and disengage the primary clutch;
• the controller being configured, upon indication from the one or more sensors that the user has commenced a stance phase wherein the user's foot contacts the ground, to operate the primary motor to engage the clutch, such that during the bending of the knee energy is extracted from the user's knee negative power and is stored in the spring as it stretches,
• the semi-passive knee exoskeleton assembly being configured to transfer energy stored in the spring to the user's knee as positive work when the user subsequently straightens the knee, thereby assisting the user's muscle in both movements, and
• the controller being further configured, upon indication, from the one or more sensors that the user has commenced a swing phase, to operate the primary motor to disengage the clutch, thereby avoiding interference by the semi-passive knee exoskeleton assembly with the user's knee motion.