Series elastic actuator
An actuator design that places a deliberate, known spring element in series between a motor's output and the joint it drives, rather than connecting them rigidly. The spring does not remove the need for a control loop, but it changes the timing and safety margin the control loop has to work within, since the spring physically absorbs the first instant of any unexpected contact or load spike before the software has to react.
Defined in 2 GAGE programs, which carry 4 distinct definitions of it. The wording above is taught in Engineering Judgment and Professional Formation.
How each discipline defines it
The same term does different work depending on who is using it. These are the definitions as each program teaches them, unedited.
An actuator design that places a deliberate, known spring element in series between a motor's output and the joint it drives, rather than connecting them rigidly. The spring does not remove the need for a control loop, but it changes the timing and safety margin the control loop has to work within, since the spring physically absorbs the first instant of any unexpected contact or load spike before the software has to react.
An actuator design that intentionally places a calibrated spring (the elastic element) in the mechanical drivetrain between the motor and the output link. The spring deflection, measured by a sensor, provides a direct measurement of joint torque. Series elastic actuators improve impact compliance and enable force control at the cost of reduced position bandwidth.
An actuator design that places a deliberately compliant element, typically a spring, between the gear train and the output joint, restoring some of the force-sensing capability that a high gear reduction would otherwise remove, at the cost of added complexity and a compliant element that itself needs its own load path check.
An actuator design that deliberately places a spring element in the mechanical path between a motor and the load it drives, functionally reproducing a tendon's shock-absorption and energy-storage behavior in an engineered component, widely used across legged robotics platforms since its introduction in the mid-1990s.
Terms it appears with
Not an alphabetical neighbourhood: these are the terms taught in the same lessons, ranked by how often they appear together.