Antagonistically Driven Differential for Mechanical Actuator

A mechanical actuator system for interacting with a mechanical load, the system comprising:

• a first mechanical differential having first and second input ports and an output port, the first and second input ports each being configured to receive respective rotational energy and the output port being configured to output the rotational energy received by the first and second input ports to the mechanical load;
• a source of rotational energy;
• a first adjustable-engagement clutch having an input port and an output port, the input port being coupled to the source of rotational energy for rotation therewith and the output port being coupled to the first input port of the first mechanical differential for rotating the first input port;
• and
• a second adjustable-engagement clutch having an input port and an output port, the input port being coupled to the source of rotational energy for rotation therewith and the output port being coupled to the second input port of the first mechanical differential for rotating the second input port;
• wherein the first and second clutches are coupled to the source of rotational energy and to the first mechanical differential so as to simultaneously provide antagonistic rotational energy to the first and second input ports of the first mechanical differential, and mechanical impedance of the output port of the first mechanical differential depends on a sum of:
• (a) a degree of engagement of the first adjustable-engagement clutch and (b) a degree of engagement of the second adjustable-engagement clutch.