Abstract: Method and apparatus for compensating for position slip in interface devices that may occur between a manipulandum and a sensor of the device due to a mechanical transmission. A device position delta is determined from a sensed position of a manipulandum of an interface device. It is determined if position slip has occurred caused by a change in position of the manipulandum that was not sensed by a sensor of the interface device, typically caused by a mechanical transmission between sensor and manipulandum. If position slip has occurred, an error in the sensed position caused by the position slip is corrected by adjusting the sensed position to take into account the position slip. The adjusted position delta is used as the position of the manipulandum and the display of objects controlled by the interface device are accordingly compensated.

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: A flexure mechanism for an interface device that interfaces a user with a computer system. An interface device includes a manipulandum physically contacted by the user. A five-bar closed-loop mechanism is coupled to the manipulandum to provide two rotary degrees of freedom to the manipulandum. The mechanism includes members coupled to each other by flexible couplings allowing rotation of the members. In preferred embodiments, four or five of the members are coupled together by flexible couplings that allow bending, thereby forming a unitary piece, where the couplings are oriented along axes of rotation of the mechanism. A senor senses a position of the manipulandum outputs a sensor signal, and in some embodiments actuators are coupled to the mechanism to output a force to the manipulandum in particular degrees of freedom. The manipulandum can be a joystick handle or portion of a sphere, where the device in one embodiment can be a handheld gamepad or similar controller.

Abstract: A method and apparatus implementing a user interface device, such as a mouse or trackball, having electronically controllable tactile responsiveness which is flexibly programmable. A user interface device effects positioning of a cursor within a limited area, such as on a display screen, with limits imposed by controllable tactile responsiveness. Programmable force-position characteristics relate the tactile responsiveness of the interface device to the position of the cursor within the limited area or on the display screen. In a described embodiment, the interface device includes at least two sets of wheels that move as the interface device is actuated. The at least two sets of wheels are aligned on mutually orthogonal axes. A servo motor is attached to each of the at least two sets of wheels.

Abstract: A prescription is provided which specifies constraints, e.g., the type (revolute and/or prismatic) and the number of joints which may be included between any two position-sensing elements (PSEs), where the joints connect the links of a kinematically constrained multi-articulated structure, whereby the defining parameters of the structure may be determined using the spatial placement of the two PSEs and the kinematic constraints of the multi-articulated structure, and where at least the spatial placement of one link is not directly measured. Also provided are preferred placements of PSEs and goniometers on a kinematically constrained multi-articulated structure which will allow determination of the spatial placement of the links, where at least the spatial placement of one link is not directly measured. Revolute joint models of the articulations of the entire human body, as well as preferred PSE and goniometer locations, are provided.

Abstract: Directional haptic feedback provided in a haptic feedback interface device. An interface device includes at least two actuator assemblies, which each include a moving inertial mass. A single control signal provided to the actuator assemblies at different magnitudes provides directional inertial sensations felt by the user. A greater magnitude waveform can be applied to one actuator to provide a sensation having a direction approximately corresponding to a position of that actuator in the housing. In another embodiment, the actuator assemblies each include a rotary inertial mass and the control signals have different duty cycles to provide directional sensations. For power-consumption efficiency, the control signals can be interlaced or pulsed at a different frequency and duty cycle to reduce average power requirements.

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 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 sesning 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 freedom. 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: Systems and methods for reducing limit cycle oscillations of a haptic device. A net force applied to the device is a combination of a primary force computed in a main haptic loop and a secondary force computed in a damping loop that cancels or minimizes the oscillations. Various algorithms for computing the secondary force are provided. In one algorithm, the secondary force is determined from the momentum error associated with crossing of a wall position by the manipulandum and is applied immediately after the crossing is detected. In another algorithm, a periodically varying secondary force with a phase shift relative to the phase of the oscillating manipulandum is computed.

Abstract: An interface device 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 orientation of the object. A device processor can be responsive to the output of the sensors and can provide the host computer with information derived from the sensors. The host computer can provides images on a display, where the computer 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 low-cost haptic feedback device that provides spatially-based sensations such as textures in correlation with a displayed graphical environment. The device includes a housing, a sensor device, and an actuator for applying a force to the user. A local processor reports relative sensor data to the host processor and receives force information from the host processor. The host force information causes a texture sensation to be output by the actuator, the texture sensation providing forces to the user at least approximately spatially correlated with predefined locations in the graphical environment as determined by a local processor. In some embodiments, the local processor can model a position of the cursor while the cursor interacts with the texture field, where the modeled position is used for determining the force output to the user, and the force information from the host can include a gating command to activate or deactivate the texture sensation when the cursor enters or exits the texture field.

Abstract: A haptic feedback touch control used to provide input to a computer. A touch input device includes a planar touch surface that provides position information to a computer based on a location of user contact. The computer can position a cursor in a displayed graphical environment based at least in part on the position information, or perform a different function. At least one actuator is also coupled to the touch input device and outputs a force to provide a haptic sensation to the user. The actuator can move the touchpad laterally, or a separate surface member can be actuated. A flat E-core actuator, piezoelectric actuator, or other types of actuators can be used to provide forces. The touch input device can include multiple different regions to control different computer functions.

Abstract: Apparatus and method for controlling force applied to and for manipulation of medical instruments. An elongated member of a medical instrument can be sensed, and an actuator can be used to apply force to the medical instrument for control and manipulation of the instrument. Via use of the applied forces, the instrument can be moved to a desired position in a working channel, haptic indications of position can be output to the user, and/or user control over the instrument can be enhanced.

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: A system and method for providing a tactile virtual reality to a user is present. The position and orientation of the user is utilized to generate a virtual reality force field. Forces are in turn generated on the user as a function of this force field. A six-axis manipulator is presented for providing a user interface to such a system. This manipulator provides a unique kinematic structure with two constant force springs which provide gravity compensation so that the manipulator effectively floats.

Abstract: A hand controller arm assembly provides for the sensing of the position of a handle at the end of an arm in the X and Y direction through supporting linkages, and in the Z direction through a hinge which permits the arm to rotate upwardly. The joints of this controller may be actuated to provide haptic feed-back.

Abstract: Methods and apparatus for controlling an actuator to provide linear and continuous force output to a user of a force feedback device. To provide continuous and smooth force output in a zero crossover region of operation, two drive signals are used, each causing current to flow in a different direction in the actuator. When a desired output force is in the crossover region, the two drive signals are alternated to cause the output force to quickly switch directions. When the desired force is outside the crossover region, only one drive signal is used to cause output force in one direction. To compensate for a nonlinear output of the actuator, a desired command current is correlated with an approximated point of a characterization curve of the actuator, where the curve includes points determined in a previously performed actuator characterization.

Abstract: Method and apparatus for controlling haptic feedback to enhance navigation of a cursor or other controlled displayed object in a graphical environment. An interface device is capable of communicating with a computer running an application program and generating a graphical environment includes an actuator for outputting a haptic effect to a user of the interface device. A modulator modulates the magnitude of the haptic effect in relation to, in various embodiments, a velocity of the cursor or user manipulatable object; a rate of interaction of the cursor with graphical objects; or an amount of time that the cursor engages the graphical object.

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: Low-cost haptic interface device implementations for interfacing a user with a host computer. A haptic feedback device, such as a mouse or other device, includes a housing physically contacted by a user, and an actuator for providing motion that causes haptic sensations on the device housing and/or on a movable portion of the housing. The device may include a sensor for detecting x-y planar motion of the housing. Embodiments include actuators with eccentric rotating masses, buttons having motion influenced by various actuator forces, and housing portions moved by actuators to generate haptic sensations to a user contacting the driven surfaces.