Force feedback interface device including grounded sensor system

An interface device for use with a host computer that displays a graphical simulation and updates said graphical simulation in response to user manipulation of said interface device, wherein said host computer commands said interface device to generate force feedback sensations in coordination with events within said graphical simulation, said interface device comprising:

• a joystick handle grasped by a user;
• a support mechanism which supports said joystick handle while allowing two rotary degrees of freedom in the motion of said joystick handle with respect to a fixed surface;
• two actuators that provide resistance to motion of said joystick handle along said two degrees of freedom with respect to said fixed surface, said resistance to motion generated by said actuators in response to host signals from said host computer, wherein said two actuators include a magnet assembly and a coil assembly, said magnet assembly grounded to said fixed surface such that said magnet assembly is fixed to and remains stationary with respect to said fixed surface, thereby allowing said joystick handle to be moved without moving a mass of said grounded portions of said actuators;
• a photo diode sensor system including two portions, wherein one portion is grounded such that it remains fixed with respect to said magnet assembly of each of said actuators and the other portion is coupled to and moves with said joystick handle, said photo diode sensor system being configured such that rotary motion of said joystick handle causes relative motion between said two portions of said sensor which can be measured by said sensor to determine a position of said joystick handle in said two degrees of freedom;
• and
• a communication interface coupling said host computer to said interface device, said communication interface reporting data from said photo diode sensor system and controlling said actuators, said communication interface including a game port.

An interface device for use with a host computer that displays a graphical simulation and updates said graphical environment in response to user manipulation of said interface device, said host computer commanding said interface device to generate force feedback sensations in coordination with events within said graphical environment, said interface device comprising:

• a user object grasped by a user;
• a support mechanism which supports said user object while allowing two degrees of freedom in the motion of said user object with respect to a grounding surface;
• two grounded actuators coupled to said support mechanism and providing a force resistance to motion of said user object along said two degrees of freedom with respect to said grounding surface, said resistance to motion generated by said actuators in response to commands from said host computer, said actuators each including a magnet assembly fixed to said grounding surface and a coil assembly coupled to and moving with said user object;
• a grounded sensor system including an optical detector and a beam source, wherein one of said optical detector and said beam source is fixed with respect to said magnet assembly and the other of said optical detector and said beam source is coupled and moves with said user object, and wherein said sensor system is configured to detect motion of said user object with respect to said grounding surface in said two degrees of freedom;
• and
• a local microprocessor separate from said host computer, said local microprocessor electrically coupled to said grounded actuators and to said grounded sensor system such that said local microprocessor controls said actuators and reads said sensor system, said local microprocessor coupled to said host computer by a Universal Serial Bus interface and executing a local process in parallel with host execution of said graphical environment.

An interface device for use with a host computer that displays and executes a graphical environment and updates said graphical environment in response to user manipulation of said interface device, said host computer commanding said interface device to generate force feedback sensations in coordination with interactions between a user-controlled graphical cursor and said graphical environment, said interface device comprising:

• a user object grasped by a user;
• a support mechanism which supports said user object while allowing two linear degrees of freedom in the motion of said user object with respect to a grounding surface;
• two actuators grounded to said grounding surface and by producing a force upon said user object in said two linear degrees of freedom with respect to said grounding surface, said force causing a resistance to motion of said user object generated by said actuators in response to commands from said host computer;
• a grounded sensor system including a lateral effect photo diode and an illumination source, wherein one of said lateral effect photo diode and said illumination source is grounded to said grounding surface, said sensor system configured to detect motion of said user object with respect to said grounding surface in at least one of said two linear degrees of freedom;
• a local microprocessor separate from said host computer, said local microprocessor electrically coupled to said actuators and to said grounded sensor system such that said local processor can control said actuators and read said grounded sensor system, said local microprocessor coupled to said host computer by a Universal Serial Bus interface, said local microprocessor executing a local process in parallel with execution of said graphical environment by said host computer;
• and
• a user adjustable switch apparatus electrically coupled to said local microprocessor, said switch apparatus providing a state signal to said local microprocessor representing a state of said switch, wherein said local microprocessor reports a representation of said state signal to said host computer such that said host computer updates said graphical environment in response to said switch state.

A method for interfacing an interface device with a host computer that displays a graphical simulation and updates said graphical simulation in response to user manipulation of said interface device, wherein said host computer commands said interface device to generate force feedback sensations in coordination with events within said graphical simulation, said method comprising:

• providing a joystick handle for a user to grasp;
• supporting said joystick handle and providing two degrees of freedom in the motion of said joystick handle with respect to a fixed surface;
• resisting motion of said joystick handle along said two degrees of freedom with respect to said fixed surface in response to host signals from said host computer, said resisting being performed using actuators including a magnet assembly and a coil assembly, said magnet assembly grounded to said fixed surface such that said magnet assembly is fixed to and remains stationary with respect to said fixed surface and said coil assembly fixed to and moving with said joystick handle, thereby allowing said joystick handle to be moved without moving a mass of said magnet assembly of said actuators;
• determining a position of said joystick handle in said two degrees of freedom using a photo diode sensor system, said sensor system including two portions, wherein one portion is grounded such that it remains fixed with respect to said magnet assembly of each of said actuators and the other portion is coupled to and moves with said joystick handle, wherein motion of said joystick handle causes relative motion between said two portions of said sensor system which can be measured by said sensor system to determine said position of said joystick handle;
• and
• reporting data from said sensor system to said host computer and controlling said actuators using a communication interface coupling said interface device to a game port of said host computer.