Parallel kinematic mechanisms with decoupled rotational motions

A method of controlling a parallel kinematic (PK) mechanism having at least pitch and yaw rotational degrees of freedom between a joystick and a frame, method comprising:

• grasping and manipulating the joystick, wherein the joystick is connected to an input joint by two or more independent paths for transmission of motion from the joystick to the frame, wherein the independent paths include a first path and a second path;
• pivoting a first intermediate body in the first path that is connected to the frame by a first connector comprising a first pivot joint, wherein the first intermediate body is coupled to the joystick by a third connector comprising a third pivot joint;
• pivoting a second intermediate body in the second path that is connected to the frame by a second connector comprising a second pivot joint, wherein the second connector is coupled to the joystick by a fourth connector, wherein the fourth connector comprises a flexible torsion shaft, wherein the first connector and the fourth connector both allow rotation in a pitch rotational direction about a pitch axis and restrict rotation in a yaw rotational direction about a yaw axis;
• further wherein the second and third connectors allow rotation in the yaw rotational direction about the yaw axis and restrict rotation in the pitch rotational direction about the pitch axis;
• wherein the joystick moves relative to the frame about a virtual center of rotation at an intersection of the pitch axis and the yaw axis;
• and
• outputting movement of the joystick relative to the frame to a computer input device.