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 method and apparatus for shaping force signals for a force feedback device. A source wave is provided and is defined by a set of control parameters (including a steady state magnitude, a frequency value and a duration value) and modified by a set of impulse parameters (including an impulse magnitude, and a settle time representing a time required for the impulse magnitude to change to the steady-state magnitude). Optionally, application parameters specifying a direction of force signal and trigger parameters specifying activating buttons can also be provided for the source wave. Using a host processor or a local processor, the force signal is formed from the source wave and the sets of control parameters and impulse parameters, where the force signal includes an impulse signal followed by a continual steady-state signal after an expiration of the settle time.

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 interface device and method for use with a host computer includes a user object, such as a joystick handle, physically contacted by a user. A support mechanism allows at least two degrees of freedom to the user object. Two actuators, preferably grounded, provide a force resistance to motion of the user object along the two degrees of freedom in response to commands from the host computer. A grounded sensor system includes an optical detector and a beam source, such as a photo diode sensor, where either the optical detector or the beam source is fixed with respect to the actuator, and the other moves with the user object. The sensor system is configured to detect motion of the user object with respect to a grounding surface in the two rotary degrees of freedom. A local microprocessor, separate from said host computer, can be included to control the actuators and read the sensor and execute a local process in parallel with host execution of a graphical environment.

Abstract: A method and apparatus for providing low cost force feedback using efficient power sourcing. A power storage device may be included in a force feedback interface device for storing power provided by an input signal. For example, the power storage device can be a capacitor. The interface device also includes an actuator for outputting forces on a user manipulatable object, such as a joystick, and the interface device is connected to a host computer. The stored power can be used, at least in part, to drive the actuator to output desired forces. A device microprocessor may also be included in the interface device to sense when the power storage device is sufficiently charged. In a different embodiment, power for the interface device is received from two sources; for example, a power supply is used for the actuators of the device and power from the host computer is used for other components of the interface device.

Abstract: A force feedback interface device including a safety feature. The interface device includes a sensor that senses the position of a user object along a degree of freedom and provides a sensor signal indicating the position of the user object to a host computer. An actuator of the device applies a force to the user object in the degree of freedom. A safety switch connected to the user object disables the actuator when the user is not using the interface device and enables the actuator when more than a predetermined amount of weight is placed on the user object.

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 providing commands to a computer through tracked manual gestures and for providing feedback to the user through forces applied to the interface. A user manipulatable object is coupled to a mechanical linkage which is, in turn, supportable on a fixed surface. The mechanical linkage or the user manipulatable object is tracked by sensors for sensing the location and/or orientation of the object. A multi-processor 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 the information provided via the microprocessor and which can provide force-feedback commands back to the microprocessor, the force feedback being felt by a user via the user manipulatable object.

Abstract: An apparatus and method for interfacing the motion of a user-manipulable object with a computer system includes a user object physically contacted or grasped by a user. A 3-D spatial mechanism is coupled to the user object, such as a stylus or a medical instrument, and provides three degrees of freedom to the user object. Three grounded actuators provide forces in the three degrees of freedom. Two of the degrees of freedom are a planar workspace provided by a closed-loop linkage of members, and the third degree of freedom is rotation of the planar workspace provided by a rotatable carriage. Capstan drive mechanisms transmit forces between actuators and the user object and include drums coupled to the carriage, pulleys coupled to grounded actuators, and flexible cables transmitting force between the pulleys and the drums. The flexibility of the cable allows the drums to rotate with the carriage while the pulleys and actuators remain fixed to ground.

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: An apparatus for interfacing an elongated flexible object with an electrical system. The apparatus includes an object receiving portion and a rotation transducer coupled to the object receiving portion adapted to determine the rotational motion of the elongated flexible object when the object is engaged with the object receiving portion and to provide an electromechanical interface between the object and the electrical system. In a preferred embodiment, the rotation transducer includes an actuator and translational transducer to provide a translational electromechanical interface between the object and the electrical system.

Abstract: A method and apparatus for interfacing the motion of a user-manipulable object with an electrical or computer system includes a user object physically contacted by a user. A gimbal mechanism is coupled to the user object, such as a joystick or a medical tool, and provides at least two degrees of freedom to the user object. The gimbal mechanism preferably includes multiple members, at least two of which are formed as a unitary member which provides flex between the selected members. An actuator applies a force along a degree of freedom to the user object in response to electrical signals produced by the computer system. A sensor detects a position of the user object along the degree of freedom and outputs sensor signals to the computer system.

Abstract: A method and apparatus for interfacing the motion of an object with a digital processing system includes a sensor which has a sensing resolution and detects movement of the object along a degree of freedom. An amount of play less than the sensing resolution exists between the sensor and the object. A passive actuator is coupled to the mechanism to transmit a resistive force to the object along the degree of freedom. A play mechanism is coupled to the actuator to provide a desired amount of play between the actuator and the object along the degree of feedom. The desired amount of play is greater than the sensing resolution of the sensor so that the sensor can detect the desired play when the user moves the object, even when the actuator has locked the object into place. Such desired play can be torsion flex (compliance) or rotary backlash. The actuator and the sensor provide an electromechanical interface between the object and the digital processing system.

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.