Abstract: The present disclosure relates to variable recruitment actuator systems and related methods. In one embodiment, a variable recruitment actuator system utilizes a central hydraulic pump, an accumulator, a plurality of variable recruitment actuators, and a pressurized reservoir of hydraulic fluid to provide highly efficient hydraulic regenerative energy harvesting in systems requiring both eccentric and concentric motion. In another embodiment, a powered prosthetic or orthotic device, or a legged robot, utilizes a system as previously described to capture energy from the eccentric motion of the knee joint to provide concentric motion of both the knee and ankle joints later on in a gait cycle.

Abstract: The present disclosure relates to variable recruitment actuator systems and related methods. In one embodiment, a variable recruitment actuator system may include a high-pressure fluid connection and a plurality of actuators. A variable recruitment actuator mechanism may selectively recruit a subset of the plurality of actuators based on a position of the variable recruitment actuator mechanism by selectively placing the subset of the plurality of actuators in fluid communication with the high-pressure fluid connection. A control system to control the position of the variable recruitment actuator mechanism may operate based on an input from a user.