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

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 low-cost haptic feedback trackball device for providing haptic feedback to a user for enhancing interactions in a graphical environment provided by a computer. The trackball device includes a sensor device that detects the movement of a sphere in two rotary degrees of freedom. An actuator applies a force preferably along a z-axis perpendicular to the plane of the surface supporting the device, where the force is transmitted through the housing to the user. The output force is correlated with interaction of a controlled graphical object, such as a cursor, with other graphical objects in the displayed graphical environment. Preferably, at least one compliant element is provided between a portion of the housing contacted by the user and the support surface, where the compliant element amplifies the force output from the actuator by allowing the contacted portion of the housing to move with respect to the support surface.

Abstract: An interface device and method for interfacing instruments to a medical procedure simulation system serve to interface peripherals in the form of mock medical instruments to the medical procedure simulation system computer to enable simulation of medical procedures. The interface device includes a housing having a mock bodily region of interest to facilitate insertion of a mock instrument, such as an endoscope tube, into the interface device. The mock bodily region of interest may be pivotable to simulate various patient orientations. The instrument is engaged by a capture mechanism in order to measure rotational and translational motion of the instrument. An actuator is disposed within the interface device to provide force feedback to the instrument. The measured motion is provided to the computer system to reflect instrument motion on the display during the simulation. Alternatively, the interface device may be configured to accommodate instrument assemblies having a plurality of nested instruments (e.g.

Abstract: A force feedback interface device is coupled to a host computer that displays a graphical environment, the device including a user manipulatable object physically contacted and moveable by a user. A sensor detects a position of the user object and provides a sensor signal to the host computer, where the sensor signal includes information representative of the position of the user object. An actuator is coupled to the device or user object and outputs a force on the user manipulatable object or a housing of the device. The actuator includes a magnet and a grounded coil, where the magnet moves approximately within a plane with respect to the coil, and wherein a current is provided in the coil to generate the force. Other embodiments provide a magnet that moves in a linear degree of freedom within a coil housing, or provide an at least partially spherical magnet providing rotary degrees of freedom to a user manipulatable object coupled to the magnet. One embodiment includes a planar frame support mechanism.

Abstract: A method and apparatus for providing a direct velocity of a moving object using nonlinear period measurement. A pulse signal from an encoder indicates the detection of a passage of a point on a moving sensor element, such as a mark on an encoder disk. A counter is then made to count down from a higher value to a lower value, where counts by the counter are made at a variable, nonlinear rate. The rate is faster when the count begins and gets slower as the count continues, reducing the possibility that the counter will overflow before the next encoder signal is received. The counter value is output and the counter is reset when another encoder signal is received, where the output value is directly related to the velocity of the object. In a different method and apparatus, first and second values, such as PWM or DAC commands, are provided to an actuator to output as forces. The values are differenced a rate of change of the force values is determined.

Abstract: Sound data output and manipulation with haptic feedback. Haptic sensations are associated with sound data to assist in navigating through and editing the sound data. The sound data is loaded into computer memory and played such that sound is output from an audio device. The sound playing is controlled by user input for navigation through the sound data. Haptic commands are generated based on the sound data and are used to output haptic sensations to the user by a haptic feedback device manipulated by the user. The haptic sensations correspond to one or more characteristics of the sound data to assist the user in discerning features of the sound data during the navigation through and editing of the sound data.

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: An interface device and method providing haptic sensations to a user. A user physically contacts a housing of the interface device, and a sensor device detects the manipulation of the interface device by the user. An actuator assembly includes an actuator that provides output forces to the user as haptic sensations. In one embodiment, the actuator outputs a rotary force, and a flexure coupled to the actuator moves an inertial mass and/or a contact member. The flexure can be a unitary member that includes flex joints allowing a portion of the flexure to be linearly moved. The flexure can converts rotary force output by the actuator to linear motion, where the linear motion causes a force that is transmitted to the user. In another embodiment, the actuator outputs a force, and a mechanism coupling the actuator to the device housing uses the force to move the actuator with respect to the device housing.

Abstract: A haptic feedback control device, such as a handheld remote control or handheld game controller, for controlling a graphical object within a graphical display and for outputting forces to a user. A housing includes a button, wherein the user engages the button with a finger. The button is depressible along a degree of freedom by the user. An actuator applies forces to the user through the button along the degree of freedom. A sensor detects displacement of the button along the degree of freedom when the button is depressed by the user. A processor, local to the device, controls the actuator to generate the forces upon the button in the degree of freedom to provide a tactile sensation to the user contacting the button.

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 digitizing system and rotary table for determining the three-dimensional geometry of an object. An apparatus includes at least one sensor detecting information describing the three-dimensional geometry of the object and providing the information to a host computer. A rotary table includes a base and a turntable rotatable about an axis positioned perpendicularly to the turntable surface. The turntable and object on its surface rotate about the axis during or between the sensor detecting the information describing the three-dimensional geometry of the object. A turntable sensor coupled to the base measures the rotation of the turntable, where the turntable sensor outputs turntable data indicative of the rotation to the host computer.

Abstract: A design interface tool for designing force sensations for use with a host computer and force feedback interface device. A force feedback device is connected to a host computer that displays the interface tool. Input from a user is received in the interface to select a type of force sensation to be commanded by a host computer and output by a force feedback interface device. Input, such as parameters, is then received from the user which designs and defines physical characteristics of the selected force sensation. A graphical representation of the characterized force sensation is displayed on the host computer which provides a visual demonstration of a feel of the characterized force sensation so that the user can view an effect of parameters on said force sensation.

Abstract: Method and apparatus for controlling magnitude and frequency of vibrotactile sensations for haptic feedback devices. A haptic feedback device, such as a gamepad controller, mouse, remote control, etc., includes a housing grasped by the user, an actuator coupled to the housing, and a mass. In some embodiments, the mass can be oscillated by the actuator and a coupling between the actuator and the mass or between the mass and the housing has a compliance that can be varied. Varying the compliance allows vibrotactile sensations having different magnitudes for a given drive signal to be output to the user grasping the housing. In other embodiments, the actuator is a rotary actuator and the mass is an eccentric mass rotatable by the actuator about an axis of rotation. The eccentric mass has an eccentricity that can be varied relative to the axis of rotation while the mass is rotating.

Abstract: A low-cost haptic feedback keyboard device for providing haptic feedback to a user for enhancing interactions in a displayed environment provided by a computer. The haptic keyboard device can be a keyboard having multiple keys, or can be a wrist rest or other attachment coupled to a keyboard. The device includes a housing that is physically contacted by the user and rests on a support surface. An actuator is coupled to the housing and applies a force to the housing approximately along an axis that is substantially perpendicular to the support surface, where the force is transmitted to the user contacting the housing. In one embodiment, the force is an inertial force that is output by moving an inertial mass. The keyboard device can be used in conjunction with another haptic device, such as a mouse, trackball, or joystick.

Abstract: The present invention provides a control knob on a device that allows a user to control functions of the device. In one embodiment, the knob is rotatable in a rotary degree of freedom and moveable in at least one transverse direction approximately perpendicular to the axis. An actuator is coupled to the knob to output a force in the rotary degree of freedom about the axis, thus providing force feedback. In a different embodiment, the knob is provided with force feedback in a rotary degree of freedom about an axis and is also moveable in a linear degree of freedom approximately parallel to the axis, allowing the knob to be pushed and/or pulled by the user. The device controlled by the knob can be a variety of types of devices, such as an audio device, video device, etc. The device can also include a display providing an image updated in response to manipulation of the knob.

Abstract: Method and apparatus for enhancing inertial tactile feedback in computer interface devices having an increased mass, such as wireless devices having the increased mass due to batteries or other power storage elements. A haptic feedback control device is in communication with a host computer and includes a housing, a sensor device that detects movement of a manipulandum or the housing, an actuator that outputs an inertial force transmitted through said housing to said user by moving an inertial mass, and a component, such as a power storage element coupled to the housing to provide power to the actuator. The component or power storage element is inertially decoupled from the housing to reduce the mass of the haptic feedback device with respect to the inertial mass, thereby allowing stronger haptic sensations to be experienced by the user for a given size of the inertial mass.

Abstract: Aspects of a current controlled motor amplifier system are provided. These aspects include a current source motor amplifier comprising current source means on each leg of a top half of the H bridge configuration and switching means on each leg of a bottom half of the H bridge configuration. A motor is coupled to the current source motor amplifier at a center portion of the H bridge configuration. Control circuitry is coupled to the current source motor amplifier for controlling the switching on of the current source motor amplifier for a predetermined time to operate the top half of the H bridge configuration essentially as a linear constant current source and the bottom half of the H bridge configuration in switching mode. The aspects also allow for simplified circuitry to protect against overvoltage conditions and eliminate electrical damping in applications with higher rotational velocities associated with induced back EMF.

Abstract: Method and apparatus for increasing the transmissibility of inertial forces produced by an inertial actuator on the housing of a tactile feedback interface device. A tactile interface device, coupled to a host computer, outputs tactile sensations to a user based on interactions and events occurring in a displayed graphical environment. An actuator produces periodic inertial forces, such as vibrations, and a compliant suspension couples the actuator to the device housing. A compliance of the suspension is selected such that the suspension magnifies the periodic inertial forces for a particular frequency range of the inertial forces. The magnified inertial forces are transmitted to the housing to be felt by the user.

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.