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. 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, web page objects, and the force feedback information. Generic force effects can 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.

Abstract: A mechanism for providing selective engagement of spring members to a user manipulatable object in a force feedback interface device. A moveable member included in a force feedback mechanism is moveable in a degree of freedom to transmit forces to the user manipulatable object, such as a joystick handle. A spring member can be selectively coupled and decoupled between a grounded member and the moveable member. The spring member provides a spring force on the moveable member that biases the joystick handle to a desired position, such as the center of the degree of freedom. A dynamic calibration procedure reduces inaccuracies when sensing the position of the user manipulandum by only reading new range limits when the actuator is not outputting a force in the direction of that limit.

Abstract: A method for providing force feedback over a network supporting TCP/IP protocols by: (a) sending from a client computer over a network supporting TCP/IP protocols, a connection request to a web server connected to the network that is hosting a desired URL; (b) receiving and processing an HTML file at the client computer that was sent from the web server in response to the connection request, wherein the processing includes parsing an embedded force object reference having associated parameters and building a force object therefrom; (c) developing a force feedback signal with the force object; and (d) providing force feedback to a human/computer interface device coupled to the client computer in response to the force feedback signal.

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 and including two 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. The grounded magnet portions of the actuators can be coupled together such that a common flux path between the magnet portions is shared by both magnets.

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: A method and apparatus for measuring three-dimensional (3-D) coordinates. A 3-D object can be digitized into a mesh representation manipulable by a computer system by tracing a stylus of a probe apparatus over surfaces of the object. The probe apparatus includes an arm having a series of linkages and joints. The arm can be assembled by placing the joints of the arm in joint fixtures a desired distance and angle apart and bonding the joints to a linkage. The probe apparatus is calibrated by placing the tip of the stylus at an arbitrary point in a work volume and varying the stylus' orientation to find error values and determine calibration parameters. The sensors of the probe apparatus are zeroed by placing the probe apparatus in the only possible home position and assigning assumed starting angles to the sensors. A rotary table can be used to support the object being digitized, where the rotation of the rotary table and object during digitization is sensed and included in coordinate calculations.

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: Improvements in accurately sensing a user manipulandum of a force feedback device. A force feedback device, coupled to a host computer, includes an actuator for outputting forces on a manipulandum and a sensor for detecting a position of the manipulandum. In one feature, a raw sensor value representing manipulandum position is adjusted based on compliance between sensor and manipulandum, where the adjustment can be based on a compliance constant and an output force. In another feature, a range of motion of the manipulandum is dynamically calibrated from startup. One boundary value of an assigned initial range is set equal to a received sensor value if the sensor value is outside the initial range, and the other boundary value is adjusted to maintain the size of the initial range unless the other boundary value has already been sensed outside the initial range.

Abstract: A method and apparatus for providing force feedback including an indexing function. A force feedback interface device is coupled to a host computer system displaying a graphical environment. A position of a user-manipulated physical object in a degree of freedom, such as a planar workspace, is sensed by the device, and a user-controlled graphical object is dislplayed on a display screen at a position corresponding to the physical object position. An indexing indication is provided by the user to activate an indexing mode, during which the user-controlled graphical object is displayed at a fixed position on said display screen, regardless of the position of the physical object. The user is able to redefine an offset between the position of the physical object and the position of tile user-controlled graphical object during the indexing mode. A safety switch can be used to activate the indexing mode.

Abstract: A method and apparatus for providing force sensations in virtual environments includes a human/computer interface device and method used in conjunction with a host computer and which can provide feel sensations to a user of the device. A user manipulatable object physically contacted by a user, such as a joystick, stylus, pool cue, or other object, is movable in multiple degrees of freedom using a gimbal mechanism. A local microprocessor, separate from the host computer, enables communication with the host computer and receives commands from the host, decodes the commands, outputs actuator signals in accordance with commands, receives sensor signals, and reports data to the host in response to commands. Actuators generate feel sensations by providing a force on the user object in response to actuator signals from the local microprocessor, and sensors detect the motion of the user object and reports sensor signals to the local microprocessor.

Abstract: A method and apparatus for providing low-cost, realistic force feedback including an improved actuator. Force sensations are provided to a user and an interface device coupled to a host computer allows a user to interact with a host application program. A user object, such as a joystick, is moveable by a user in at least one rotary degree of freedom. A sensor reports a locative signal to the host computer to indicate a position of the user object. An actuator outputs forces on the user object in response to signals from the host computer and program. The actuator includes a housing, a set of grounded magnets provided on opposing surfaces of the housing and creating a magnetic field, and a rotor coupled to the user object positioned between the magnets. The rotor rotates about an axis of rotation and includes a shaft and teeth spaced around the shaft. An electric current flows through one or more coils on the teeth to cause the rotor to rotate.

Abstract: A method and apparatus for use with a computer for tracking the position of a user manipulatable object and for providing forces to lock the apparatus. The manipulatable object is coupled to a mechanical linkage which is supportable on a fixed surface and is tracked by sensors for sensing the location and/or orientation of the object. Force generators coupled to the linkage can lock one or more joints of the linkage in position. A multiprocessor system architecture is disclosed wherein a host computer system is interfaced with a dedicated 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 which responds to sensor information and can display images in accordance therewith.

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 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 mechanical interface for providing high bandwidth and low noise mechanical input and output for computer systems. A gimbal mechanism includes multiple members that are pivotably coupled to each other to provide two revolute degrees of freedom to a user manipulatable about a pivot point located remotely from the members at about an intersection of the axes of rotation of the members. A linear axis member, coupled to the user object, is coupled to at least one of the members, extends through the remote pivot point and is movable in the two rotary degrees of freedom and a third linear degree of freedom. Transducers associated with the provided degrees of freedom include sensors and actuators and provide an electromechanical interface between the object and a computer. Capstan band drive mechanisms transmit forces between the transducers and the object and include a capstan and flat bands, where the flat bands transmit motion and force between the capstan and interface members.

Abstract: A force feedback interface and method providing a selective disturbance filter for providing selective reduction or elimination of displayed disturbances associated with output force sensations. A force feedback interface device is connected to a host computer that displays a 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. A microprocessor outputs controlling force signals to the actuator, receives sensor signals from the sensors and reports locative data to the host computer indicative of the movement of the user object. The host computer updates a position of a displayed user-controlled graphical object in the graphical environment based on the reported data.

Abstract: A high-fidelity mechanical transmission system for transmitting forces which can be used in a human-computer force feedback interface device connected to a host computer. The transmission system includes multiple stages, including an actuator stage coupled to an actuator and one or more additional stages. The actuator stage includes a rotatable capstan pulley coupled to the actuator, a cylindrical capstan drum, and a flexible member, such as a cable, coupling the capstan pulley and drum. The cable is coupled to the capstan drum at both ends, and causes the capstan drum to rotate for multiple revolutions. The output stage is coupled to the driven object to rotate the driven object. The output stage can include a capstan pulley, capstan drum, and cable. An interface device can include the transmission system for inputting motion signals to a connected host computer and for providing force feedback to the user.

Abstract: A method for assembling a linkage assembly for a 3-D Digitizing Probe Apparatus. A linkage assembly for incorporation into the probe apparatus includes a linkage and a joint member provided at each end of the linkage. Joint fixtures for receiving and holding the joints are provided at a desired distance and orientation apart. The joint members are loosely coupled to the linkage and are moved relative to the linkage so that the joint members fit in the joint fixtures and so that the linkage provides a desired length between the joints. The joint members are bonded to the linkage while the assembly is in the fixtures, thus fastening the components of the assembly together with minimal stress to the assembly and providing a precise linkage length and orientation of joints in the assembly.

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: A percussion system including at least one force transducer developing a variable resistance output based upon a force exerted upon its surface, an interface providing an interface output based upon the analog output of the force transducer, and a digital processing system coupled to the interface. The analog input is preferably a variable resistance, and the interface output is preferably a pulse having a width related to the variable resistance. The interface preferably includes a capacitive member to form an RC circuit with the force transducer, and circuitry responsive to the RC circuit to produce a digital output. The digital processing system stores the digital output of the interface in memory and processes the digital output with other digital outputs of the interface to perform a computer implemented process such as producing a synthesized drum sound.