Force feedback interface having isotonic and isometric functionality

A method of providing an isometric control mode for an interface device coupled to a host computer, the method comprising:

• receiving an indication to engage an isometric control mode of said interface device;
• determining a deviation of a user manipulable physical object in a provided plurality of degrees of freedom, said deviation indicative of an input force from said user on said user manipulable object;
• applying a resistive force using an computer-controlled actuator to said user manipulable object opposing said input force;
• and
• using said determined deviation to control an isometric function of an application program implemented by said host computer.

A method for enabling isotonic and isometric control from a user utilizing a single interface device coupled to a host computer system displaying a graphical environment, the method comprising:

• receiving a selection of a control mode of said interface device, wherein said control mode is either an isotonic control mode or an isometric control mode;
• providing isotonic input to said host computer system if said interface device is in said isotonic mode, wherein said isotonic input is used by said host computer system to update a position of a user-controlled graphical object in said graphical environment to correspond to a position of a user-manipulated physical object in provided degrees of freedom;
• and
• providing isometric input to said host computer system if said interface device is in said isometric mode, wherein said isometric input is used by said host computer system to control an isometric function of said graphical environment based on an input force applied by said user to said physical object, said isometric input being provided as input force from said user opposing an output force generated by computer-controlled actuators.

A method for providing isometric input from an interface device to a host computer displaying a graphical environment on a display device, said method comprising:

• displaying a user-controlled graphical object at a position in said graphical environment displayed by said host computer;
• receiving input to said host computer from said interface device indicating movement of a user manipulatable physical object of said interface device caused by a user;
• implementing an isometric function of said graphical environment utilizing said input;
• maintaining said user-controlled graphical object at said position in said graphical environment regardless of said movement of said user manipulable physical object.

A force feedback interface device for interfacing with a host computer implementing an application program, said interface device comprising:

• a user manipulandum being physically contacted by a user of said interface device and moveable within a planar workspace;
• mode selection means for selecting a control mode for said user manipulandum and said interface device, said control mode being either an isotonic control mode or an isometric control mode;
• an actuator coupled to said user manipulandum for applying forces to said user manipulandum;
• a sensor operative to detect a deviation of said user manipulandum from said local origin caused by said user and output sensor signals;
• and
• a local microprocessor coupled to said actuator and to said sensor and being separate from said host computer, said local microprocessor receiving said sensor signals and providing actuator signals to said actuator, wherein said local microprocessor is coupled to said host computer by a communication bus.

An apparatus for interfacing isotonic and isometric interactions between a user utilizing a single interface device and a host computer system displaying a graphical environment, the apparatus comprising:

• means for receiving a selection of a control mode of said interface device, wherein said control mode is either an isotonic control mode or an isometric control mode;
• means for providing isotonic input to said host computer system if said interface device is in said isotonic mode, wherein said isotonic input is used by said host computer system to update a position of a user-controlled graphical object in said graphical environment to correspond to a position of a user-manipulated physical object in provided degrees of freedom;
• means for applying a force to said physical object in said isotonic mode;
• and
• means for providing isometric input to said host computer system if said interface device is in said isometric mode, wherein said isometric input is used by said host computer system to control an isometric function of said graphical environment based on an input force applied by said user to said physical object, wherein said input force is determined based on a user-imparted physical deviation of said user manipulable object in one or more of said degrees of freedom.