Massachusetts Institute of Technology

Hewlett-packard Development Company, L.p.

Compaq Information Technologies Group, L.p.

Craig B Zilles

David Lawrence Brock

Thomas Harold Massie

Mandayam A Srinivasan

Hugh B Morgenbesser

Joel S Emer

Tryggve Fossum

James E Hicks, Jr

Bruce Edwards

J Kenneth Salisbury

Matthew H Reilly

Christopher F Joerg

Rebecca L Stamm

J Kenneth Salisbury, Jr

A method and apparatus for determining forces to be applied to a user through a haptic interface. The method includes the steps of generating a representation of an object in graphic space, sensing the position of the user in real space and calculating a force to be applied to a user in response to the user's haptic interface and the user's fiducial object. The user's fiducial object represents the location in graphic space at which the user's haptic interface would be located if the haptic interface could not penetrate the surfaces of virtual objects.

Method and apparatus for determining forces to be applied to a user through a haptic interface

Execution of a program's instructions in a simultaneous multithreaded processor is halted while the program is waiting for one or more events to occur by first arming an event monitor upon an arm instruction, that is, identifying to the event monitor one or more events to be monitored, such as a modification to a value or state of an identified memory location or group of locations, and setting a watch flag to indicate enable the event monitor. Upon execution of a quiesce request instruction, the program quiesces if the watch flag is set, and a timer is started. Upon observation by the event monitor of an identified event, or upon expiration of the timer, the watch flag is cleared and execution of the program resumes.

Temporary halting of thread execution until monitoring of armed events to memory location identified in working registers

Method and apparatus to quiesce a portion of a simultaneous multithreaded central processing unit

A method and apparatus for determining forces to be applied to a user through a haptic interface. The method includes the steps of generating a representation of an object in graphic space, sensing the position of the user in real space and calculating a force to be applied to a user in response to the user's haptic interface and the user's fiducial object. The user's fiducial object represents the location in graphic space at which the user's haptic interface would be located if the haptic interface could not penetrate the surfaces of virtual objects. In one embodiment, the method calculates a stiffness force to be applied to the user. In other embodiments, the method calculates damping and friction forces to be applied to the user. In one embodiment the step of generating a representation of an object in graphic space includes defining the object as a mesh of planar surfaces and associating surface condition values to each of the nodes defining the planar surfaces. In another embodiment, the step of generating a representation of an object in graphic space includes describing the surface of the object using a coordinate system and associating surface condition values with each set of coordinates of the coordinate system.

Method and apparatus for determining forces to be applied to a user

Growing community of inventors

Middleton, WI, United States of America

Craig B Zilles