Abstract: Methods are presented for authoring geometrical databases which incorporate touch or haptic feedback. In particular, a database of geometrical elements incorporates attributes necessary to support haptic interactions such as stiffness, hardness, friction, and so forth. Users may instantiate objects designed through CAD/CAM environments or attach haptic or touch attributes to subcomponents such as surfaces or solid sub-objects. The resulting haptic/visual databases or world-describing models can then be viewed and touched using a haptic browser or other appropriate user interface.

Abstract: A force feedback cursor control interface for use with a computer that provides locative data to a computer for tracking a user manipulatable physical object and provides feedback to the user through output forces. The physical object is movable in multiple degrees of freedom and is tracked by sensors for sensing the location and/or orientation of the object. A multi-processor system architecture is disclosed wherein the host computer is interfaced with a device microprocessor which is responsive to the output of the sensors and provides the host computer with information derived from the sensors. The host computer runs an application program and provides images on a display, where the program responds to the provided sensor information and force feedback is correlated with the displayed images via force feedback commands from the host computer.

Abstract: A method and apparatus for providing force feedback to a user operating a human/computer interface device and interacting with a computer-generated simulation. In one aspect, a computer-implemented method simulates the interaction of simulated objects displayed to a user who controls one of the simulated objects manipulating a physical object of an interface device. The position of the simulated object, as provided within the simulation and as displayed, is mapped directly to the physical position of the user object. This mapping is broken under conditions that are effective to provide force feedback to the user which imparts a physical sensation corresponding to the interaction of the simulated objects. In another aspect, a ball simulated ball object interacts with a user-controlled simulated object in a simulation to allow the user to utilize a wide range of physical skill and dexterity in interacting with the simulation.

Abstract: A method and apparatus for controlling and providing force feedback using an interface device manipulated by a user. A microprocessor is provided local to the interface device and reads sensor data from sensors that describes the position and/or other information about an object grasped and moved by the user, such as a joystick. The microprocessor provides the sensor data to a host computer that is coupled to the interface device by a communication bus that preferably includes a serial interface. In a “host-controlled” embodiment, the host computer calculates force values using the sensor data and other parameters of a host application program and sends the force values to the local microprocessor, which directly provides the force values to actuators to apply forces to the user object.

Abstract: An apparatus for interfacing the movement of a shaft with a computer includes a support, a gimbal mechanism having two degrees of freedom, and three electromechanical transducers. When a shaft is engaged with the gimbal mechanism, it can move with three degrees of freedom in a spherical coordinate space, where each degree of freedom is sensed by one of the three transducers. A fourth transducer can be used to sense rotation of the shaft around an axis.

Abstract: An interface device and method for providing enhanced cursor control with force feedback. A force feedback interface device includes a manipulandum, such as a mouse, that is moveable in a local workspace. The device is coupled to a host computer that displays a cursor in a graphical environment, such as a GUI, on a display screen. An interior region and a border region in the local workspace is defined. One mapping of device movement to cursor movement is used for the interior region, and a different mapping is used for the border region. Mapping methods include ballistics, absolute, linear, rate control, and variable absolute. Rate control embodiments can be single axis or dual axis. In one embodiment, when the mouse moves from the interior region to the border region, the mapping providing the greater cursor velocity is used to better conserve device workspace in the direction of travel and to decrease any sense of mapping mode change to the user.

Abstract: Method and apparatus for providing high strength, low frequency tactile sensations using an inertial actuator in a haptic feedback interface device, such as an actuator driving an oscillating inertial mass. A commanded low frequency is modulated or combined with a higher frequency at which the tactile sensations feel stronger, where the resulting signal is used to output a tactile sensation at the higher frequency and convey the commanded low frequency to the user. One embodiment provides higher frequency pulse bursts at the desired low frequency; other embodiments modulate or otherwise vary the amplitude of the higher frequency signal according to the desired low frequency.

Abstract: A force feedback mouse interface device connected to a host computer and providing realistic force feedback to a user. The mouse interface device includes a mouse object and a linkage coupled to the mouse that includes a plurality of members rotatably coupled to each other in a planar closed-loop linkage, two of the members coupled to ground and rotatable about the same axis. Two actuators, preferably electromagnetic voice coils, provide forces in the two degrees of freedom of the planar workspace of the mouse object. Each of the actuators includes a moveable coil portion integrated with one of the members of the linkage and a magnet portion coupled to the ground surface through which the coil portion moves. At least one sensor is coupled to the ground surface that detects movement of the linkage and provides a sensor signal including information from which a position of the mouse object in the planar workspace can be determined.

Abstract: A force feedback interface and method including an actuator in a non-primary axis or degree of freedom. The force feedback interface device is connected to a host computer that implements a host application program or graphical environment. The interface device includes a user manipulatable object, a sensor for detecting movement of the user object, and an actuator to apply output forces to the user object. The actuator outputs a linear force on the user object in non-primary linear axis or degree of freedom that is not used to control a graphical object or entity implemented by the host computer, and movement in the non-primary degree of freedom is preferably not sensed by sensors. The axis extends through the user object, and there are preferably no other actuators in the device, thus allowing the force feedback device to be very cost effective. Force sensations such as a jolt, vibration, a constant force, and a texture force can be output on the user object with the actuator.

Abstract: Force feedback is provided to a user of a client computer receiving information such as a web page over a network such as the World Wide Web from a server machine. The client machine has a force feedback interface device through which the user experiences physical force feedback. The web page may include force feedback information to provide authored force effects. Force feedback is correlated to web page objects by a force feedback program running on the client and based on input information from the interface device, the web page objects, and the force feedback information. Generic force effects can also be provided, which are applied uniformly at the client machine to all web page objects of a particular type as defined by user preferences at the client machine. A web page authoring interface is also described that includes the ability to add force sensations to a web page. The user may assign force effects to web page objects and immediately feel how the web page will feel to an end user.

Abstract: A method and apparatus for providing force feedback to a user operating a human/computer interface device and interacting with a computer-generated simulation. In one aspect, a computer-implemented method simulates the interaction of simulated objects displayed to a user who controls one of the simulated objects manipulating a physical object of an interface device. The position of the simulated object, as provided within the simulation and as displayed, is mapped directly to the physical position of the user object. This mapping is broken under conditions that are effective to provide force feedback to the user which imparts a physical sensation corresponding to the interaction of the simulated objects. In another aspect, a ball simulated ball object interacts with a user-controlled simulated object in a simulation to allow the user to ufilize a wide range of physical skill and dexterity in interacting with the simulation.

Abstract: A force feedback interface device including safety features. The interface device includes a sensor that senses the position of a user manipulatable object in a degree of freedom and provides a sensor signal indicating the position of the user manipulatable object to a host computer. An actuator of the device applies a force to the user manipulatable object in the degree of freedom. A safety switch of the interface device disables the actuator when the user is not using the interface device and enables the actuator when the user is using the device. A device is included in the interface device to execute a force ramping process when the safety switch enables the actuator, the force ramping process causing the force to be produced at a reduced magnitude and slowly increased to a desired magnitude over a period of time to avoid an abrupt application of initial force.

Abstract: A method and apparatus for providing high bandwidth and low noise mechanical input and output for computer systems. A gimbal mechanism provides two revolute degrees of freedom to an object about two axes of rotation. A linear axis member is coupled to the gimbal mechanism at the intersection of the two axes of rotation. The linear axis member is capable of being translated along a third axis to provide a third degree of freedom. The user object is coupled to the linear axis member and is thus translatable along the third axis so that the object can be moved along all three degrees of freedom. Transducers associated with the provided degrees of freedom include sensors and actuators and provide an electromechanical interface between the object and a digital processing system. Capstan drive mechanisms transmit forces between the transducers and the object.

Abstract: A force feedback interface including a haptic accelerator that relieves the computational burden associated with force feedback generation from a force feedback processor. The force feedback processor is preferably a device microprocessor included in the interface device and separate from a controlling host computer for determining forces to be output. The haptic accelerator quickly determines velocity and/or acceleration information describing motion of a user manipulatable object from raw position data received from sensors of the interface device and representing the position of the user object. The velocity and/or acceleration data is used by the force feedback processor in the determination of forces to be output on the user object.

Abstract: Methods and apparatus for efficient management of memory in a force feedback system including a host computer and a force feedback device. A representation of device memory is maintained on the host computer to allow the host computer knowledge and control over storage and force effects in the device memory. A host cache for force effects is provided to allow almost unlimited numbers of force effects to be created for the device, where any force effects not able to fit in device memory are stored in the host cache.

Abstract: A mouse interface device and method for providing enhanced cursor control and indexing cursor control with force feedback. A force feedback interface device includes a manipulandum, such as a mouse, that is moveable in a local workspace. The device is coupled to a host computer that displays a cursor in a graphical environment, such as a GUI, on a display screen. A cursor position in the display frame is reported to the host computer derived from a reference position of the mouse in the local frame, and the host displays the cursor; for example, the cursor position may be scaled by a ballistics algorithm based on mouse velocity to allow fine positioning or coarse motion of the cursor. A force is output on the mouse based on interactions in the GUI, the force being determined based on mouse reference data or cursor ballistic data, depending on the type of force, to reduce distortion between visual and force outputs. Assistive forces can alternatively be output to achieve the enhanced cursor control.

Abstract: An apparatus for interfacing the movement of a shaft with a computer includes a support, a gimbal mechanism having two degrees of freedom, and three electromechanical transducers. When a shaft is engaged with the gimbal mechanism, it can move with three degrees of freedom in a spherical coordinate space, where each degree of freedom is sensed by one of the three transducers. A fourth transducer can be used to sense rotation of the shaft around an axis.

Abstract: A force feedback interface having isotonic and isometric control capability coupled to a host computer that displays a graphical environment such as a GUI. The interface includes a user manipulatable physical object movable in physical space, such as a mouse or puck. A sensor detects the object's movement and an actuator applies output force on the physical object. A mode selector selects isotonic and isometric control modes of the interface from an input device such as a physical button or from an interaction between graphical objects. Isotonic mode provides input to the host computer based on a position of the physical object and updates a position of a cursor, and force sensations can be applied to the physical object based on movement of the cursor. Isometric mode provides input to the host computer based on an input force applied by the user to the physical object, where the input force is determined from a sensed deviation of the physical object in space.

Abstract: A method and apparatus for providing a click surface in a graphical environment, such as a graphical user interface, implemented on a host computer for use with a force feedback interface device. A displayed cursor is controlled by a user-moveable user object, such as a mouse, of the interface device. A click surface is displayed with an associated graphical object, such as a graphical button or an edge of a window, icon, or other object. When the click surface is contacted by the cursor, a force is output opposing movement of the user object in a direction into the click surface and into the graphical object. When the user object has moved to or past a trigger position past the contact with the click surface, a command gesture signal is provided to the host computer indicating that the graphical object has been selected as if a physical input device on the user object, such as a button, has been activated by the user.

Abstract: A pen-based direct-drive manipulator enables precision manipulation and force display of a control point within three degrees of freedom. The control point exhibits substantially no backlash, very low friction and very low inertia making it useful as a force display. The manipulator also has a very high force generation bandwidth allowing high frequency force components to be displayed. A parallel actuator structure controls motion over two degrees of freedom in a horizontal plane. The parallel structure is a redundant structure including three chains in parallel coupled at the control point. The redundant structure provides a uniform force capability throughout the manipulator workspace. A pair of rotational actuators rotate the parallel structure about an axis to approximate a linear motion along a third axis. The rotational actuators provide a third degree of freedom for the control point. Motion about the third axis is substantially decouple from motion about the horizontal plane.