Abstract: A six degree of freedom force reflecting haptic interface includes three powered axes and three free axes, all of which are tracked so that the position of a user connection element in the work volume can be determined. The interface includes cable drives with polymer composite or metallic cables, automatic cable tensioning devices, and grounded actuator capstans. A nested hub and transfer drive provide a compact, weight balanced interface. User comfort and safety features are also provided.

Abstract: A user of a modeling application uses a haptic interface device in the real world to manipulate a virtual tool in a virtual environment to interact with a virtual object. The user can use the tool to evaluate the shape of the virtual object and navigate its virtual surface, based on an interactive force feedback approach. When the user attempts to penetrate the virtual object with the virtual tool, a modeling application limits the movement of the virtual tool depending on the geometry of the surface, the position of the virtual tool, and a haptic interface location in the virtual environment, which represents the physical location of the haptic interface device in the real world. The user can evaluate different geometries of the virtual surface, including an edge geometry, such as occurs when the virtual tool is touching or moving along an edge of the virtual object.

Abstract: A six degree of freedom force reflecting haptic interface includes three powered axes and three free axes, all of which are tracked so that the position of a user connection element in the work volume can be determined. The interface includes cable drives with polymer composite or metallic cables, automatic cable tensioning devices, and grounded actuator capstans. A nested hub and transfer drive provide a compact, weight balanced interface. User comfort and safety features are also provided.

Abstract: The invention is an apparatus for physically exchanging a force with a user in an environment local to the user. A connection element connects to a user's body member and a linkage between the connection element and ground. The linkage includes means for powering at least three independent freedoms of the connection element relative to ground and means for maintaining at least one independent freedom of the connection element relative to ground free of power. Up to three independent freedoms of the connection element may be maintained free of power, and up to five independent freedoms may be powered. Other aspects of the invention include a two actuator counter-balance for controlling a point on a link. The invention also includes apparatus for establishing a virtual, switch, which presents to the user the force and displacement relationship of a spring switch.

Abstract: A method and apparatus for determining forces to be applied to a user through a haptic interface. The method includes the steps of generating a representation of an object in graphic space, sensing the position of the user in real space and calculating a force to be applied to a user in response to the user's haptic interface and the user's fiducial object. The user's fiducial object represents the location in graphic space at which the user's haptic interface would be located if the haptic interface could not penetrate the surfaces of virtual objects. In one embodiment, the method calculates a stiffness force to be applied to the user. In other embodiments, the method calculates damping and friction forces to be applied to the user. In one embodiment the step of generating a representation of an object in graphic space includes defining the object as a mesh of planar surfaces and associating surface condition values to each of the nodes defining the planar surfaces.

Abstract: A method and apparatus for determining forces to be applied to a user through a haptic interface. The method includes the steps of generating a representation of an object in graphic space, sensing the position of the user in real space and calculating a force to be applied to a user in response to the user's haptic interface and the user's fiducial object. The user's fiducial object represents the location in graphic space at which the user's haptic interface would be located if the haptic interface could not penetrate the surfaces of virtual objects. In one embodiment, the method calculates a stiffness force to be applied to the user. In other embodiments, the method calculates damping and friction forces to be applied to the user. In one embodiment the step of generating a representation of an object in graphic space includes defining the object as a mesh of planar surfaces and associating surface condition values to each of the nodes defining the planar surfaces.

Abstract: An apparatus and method for physically exchanging a force with a user in a user-local environment. The apparatus includes a user connection element and a linkage physically linking the user connection element to a reference. The linkage provides at least six independent degrees of freedom to the user connection element. The linkage has an actuator system which powers at least three degrees of freedom of the user connection element, while at least three degrees of freedom remain unpowered. The method includes providing an apparatus which includes a user connection element and a linkage physically linking the user connection element to a reference, the linkage providing at least six independent degrees of freedom to the user connection element. The linkage of the apparatus provided has an actuator system which powers at least three of the six independent degrees of freedom relative to the reference.

Abstract: A connection element such as a thimble connects to a user's body member and, through a linkage, to a ground reference. The apparatus physically exchanges a force with a user in an environment local to the user. The linkage powers at least three independent freedoms of the connection element relative to the reference. It also maintains at least one independent freedom of the connection element relative to the reference free of power. Up to three independent freedoms of the connection element may be maintained free of power, and up to five independent freedoms may be powered. A gimbal connects the gimbal to the linkage. Zero, one or two of the gimbal axes may be powered. A five bar linkage connects the connection element to a counter-balance that also includes two actuators. A third actuator connects the five bar linkage to the reference. The two actuators of the counterbalance may be connected to the next link in the chain to the reference through a single cable.

Abstract: A connection element such as a thimble connects to a user's body member, through a linkage, to a ground reference. The apparatus physically exchanges a force with a user in an environment local to the user. The linkage powers at least three independent freedoms of the connection element relative to the reference. It also maintains at least one independent freedom of the connection element relative to the reference free of power. Up to three independent freedoms of the connection element may be maintained free of power, and up to five independent freedoms may be powered. A gimbal connects the gimbal to the linkage. Zero, one or two of the gimbal axes may be powered. A five bar linkage connects the connection element to a counter-balance that also includes two actuators. A third actuator connects the five bar linkage to the reference. The two actuators of the counterbalance may be connected to the next link in the chain to the reference through a single cable.