System and method for tensioning a robotically actuated tendon

A system for providing an increased grasping force through a finger of a dexterous robot during a grasping routine, the system comprising:

• a tendon having a proximal end and a distal end and extending along a length of a finger of a dexterous robot, the distal end of the tendon being coupled to the finger;
• a finger actuator including a drive screw and a motor and located in a lower arm assembly of the dexterous robot and apart from the finger, the finger actuator coupled with the proximal end of the tendon and configured to apply a tension through the tendon in response to an electrical current;
• and
• a motor controller electrically coupled with the finger actuator, the motor controller configured to:
• provide an electrical current having a first amplitude to the finger actuator until a stall tension is achieved through the tendon;
• provide a pulse current to the actuator following the achievement of the stall tension, the amplitude of the pulse current being greater than the first amplitude;
• and
• return the motor to a steady state holding current following the conclusion of the pulse current.

A method for controlling an actuator to tension a tendon, the method comprising:

• providing a tendon having a proximal end and a distal end;
• providing an actuator coupled with the proximal end of the tendon and configured to apply a tension through the tendon in response to an electrical current, the actuator including a drive screw and a motor;
• driving the actuator with an electrical current having a first amplitude until a stall tension is achieved through the tendon;
• delivering a pulse current to the actuator following the achievement of the stall tension, the amplitude of the pulse current being greater than the first amplitude;
• and
• returning the electrical current delivered to the motor to a steady state holding amplitude following the conclusion of the pulse current.