Kinematics of a mechanical end effector for a humanoid robot

An underactuated end effector for a humanoid robot, the end effector comprising:

• a frame;
• a thumb assembly removably coupled to the frame and including:
• a motor assembly including a first motor and a second motor;
• a gear assembly coupled to a digit assembly and comprising:
• a flexion gear configured to be rotated by the first motor, and wherein said rotation of the flexion gear moves the digit assembly between a hyperextended state and a flexed state;
• an interposition gear configured to be driven by the second motor, and wherein said rotation of the interposition gear moves the digit assembly between an unrotated state and a rotated state;
• and a carpometacarpal joint housing assembly configured to rotate in response to rotation of the interposition gear.

An underactuated end effector for a humanoid robot, the end effector comprising:

• a frame;
• a thumb assembly removably coupled to the frame and including:
• a motor assembly including a first motor with a first motor shaft rotatable about a first motor shaft axis and a second motor with a second motor shaft rotatable about a second motor shaft axis, and wherein the first and second motor shaft axes are both oriented at acute angles relative to a sagittal plane of the end effector;
• a gear assembly coupled to a digit assembly and comprising:
• a flexion gear configured to be rotated by the first motor, and wherein said rotation of the flexion gear moves the digit assembly between a hyperextended state and a flexed state;
• and
• an interposition gear configured to be driven by the second motor, and wherein said rotation of the interposition gear moves the digit assembly between an unrotated state and a rotated state.