Passive robotic constraint devices using non-holonomic transmission elements

摘要

A passive constraint device for implementing a programmable virtual constraint surface, comprises one or more non-holonomic kinematic transmission element for coupling velocities of motion and having a steering angle. A user moves the handle of the passive constraint device relative to the virtual surface. A steering motor sets the steering angle of the non-holonomic element in response to the proximity of the handle to the virtual surface. When in contact with the virtual surface, the steering angle is set so as to prohibit any motion which would penetrate the surface. When not in contact with the virtual surface, the steering motor adjusts the steering angle in response to the user's applied forces, to provide apparent freedom of motion to the user.