A pick-and-place manipulator with two actuators typically moves in which planes?

• A. X and Y
• B. Y and Z
• C. X and Z
• D. X, Y and Z

Answer: (C)

Two actuators give two degrees of freedom, so the manipulator can move only within a single plane. In common pick-and-place designs these two axes are horizontal and vertical, i.e., the X and Z directions, so the motion lies in the XZ plane. The Y axis represents depth and would need a third actuator to move through all three dimensions, which isn’t available here. So the motion is in the XZ plane.