Method and apparatus for tracking the position and orientation of a stylus and for digitizing a 3-D object

A method for locating the position and orientation of a rotary table apparatus with reference to a probe apparatus for measuring three-dimensional coordinates of a physical object positioned on the rotary table apparatus, the method comprising the steps of:

• placing a tip of a stylus of said probe apparatus in a receptacle positioned near a periphery of a turntable of said rotary table apparatus, wherein said probe apparatus includes a linkage of members provided as an arm with said stylus at an end of said arm, said stylus being moveable in a plurality of degrees of freedom;
• rotating said turntable about a central axis while said stylus tip is positioned in said receptacle;
• sampling a plurality of positions and orientations of said stylus using sensors included in said linkage of said probe apparatus as said turntable is rotated;
• sampling an angular position of said turntable about said central axis at each of said sampled plurality of positions and orientations of said stylus, wherein a sensor included in said turntable senses said angular position;
• and
• determining the position and orientation of said rotary table apparatus relative to said probe apparatus utilizing said sampled plurality of positions and orientations of said stylus and said sampled angular positions of said turntable, thereby subsequently allowing a physical object on said rotary table, having its coordinates measured by said probe apparatus, to be rotated on said rotary table during said measuring process.

A probe system for measuring the three-dimensional geometry of an object and providing information describing said three-dimensional geometry to a host computer system, the probe system comprising:

• (a) a probe apparatus including a base and a probe having multiple degrees of freedom, said probe coupled to said base by a plurality of links and joint members such that said probe and each of said links is coupled to at least one of said joint members, said probe apparatus including a plurality of sensors measuring probe data defining a position and orientation of said probe, and wherein said probe is used to physically trace a surface of said object to provide said information describing said three-dimensional geometry to said host computer system;
• (b) a rotary table including:
• (i) a base;
• (ii) a turntable coupled to said base and rotatable about an axis positioned perpendicularly to a surface of said turntable, said turntable for receiving on its surface said object to be measured and allowing a user to move said turntable and said object about said axis during said measuring of said geometry of said object to allow convenient tracing of said surface of said object with said probe;
• and
• (iii) a turntable sensor coupled to said base, said sensor being operative to measure a rotation of said turntable about said axis, wherein said sensor outputs turntable data indicative of said rotation;
• and
• (c) an interface microprocessor separate from said host computer system and coupled to said probe apparatus, said turntable sensor, and said host computer system, said microprocessor being adapted to receive said probe data and said turntable data and providing information derived from said probe data and said turntable data to said host computer system, wherein said turntable data is used to locate said object on said rotary table with respect to said probe after said rotation.

A method for measuring three dimensional geometry of an object using a probe apparatus, where said object is positioned on a rotary table, the method comprising:

• providing a probe apparatus on a fixed surface, said probe apparatus including a serial linkage of members coupled to a base, said base coupled to said fixed surface, wherein a stylus for a user to hold is provided at an end of said linkage of members;
• providing a rotary table on said fixed surface, said rotary table including a rotatable surface, wherein an object is positioned on said rotatable surface;
• measuring coordinates of said object by measuring a location of a tip of said stylus measured with respect to said base of said probe apparatus using sensors included in said linkage of members, said stylus being held by said user to allow said tip to contact a surface of said object when said coordinates are measured;
• measuring a rotational motion of said rotatable surface and said object with respect to said base of said probe apparatus using a rotary sensor included in said rotary table;
• and
• continuing to measure coordinates of said object after said rotation by measuring a location of said tip of said stylus with respect to said base of said probe apparatus when said stylus is held by said user such that said tip contacts said surface of said object, said continuation of said measuring of said coordinates being performed without measuring multiple coordinates of said object with said stylus to relocate said object with respect to said base after said rotation.

A human computer interface apparatus for allowing a user to manually manipulate a probe within a three dimensional volume while a host computer tracks a position and orientation of said probe with respect to a fixed surface within said volume, said host computer displaying a user-controlled image on a display screen at a position derived from a position of said probe in said three dimensional volume, wherein said interface apparatus allows said probe to be moved in at least five degrees of freedom with respect to said fixed surface, said interface apparatus comprising:

• a probe manipulatable by a user;
• a support base;
• a movable linkage including a first, second, and third joint configuration, wherein said first joint configuration couples said probe to a first link member, allowing said probe to move in two degrees of freedom of rotation with respect to said first link member, said second joint configuration couples said first link member to a second link member, allowing rotation of said first link member with respect to said second link member, and said third joint configuration couples said second link member to said support base, allowing said second link member to move in two degrees of freedom of rotation with respect to said support base;
• at least one sensor associated with each of said first, second, and third joint configurations, wherein each of said sensors measures said rotation in a degree of freedom allowed by said joint configurations;
• and
• a microprocessor electrically coupled to said sensors and separate from said host computer system, said microprocessor reading data from said sensors and reporting a representation of said data to said host computer, said microprocessor receiving, decoding, and responding to high level host commands sent from said host computer, wherein said high level host commands include requests to report a single set of said representation of said data, requests to report a repeated stream of said representations of said data over time, and requests to modify parameters stored within memory local to said microprocessor and separate from said host computer.

A system for measuring spatial coordinates and controlling a cursor displayed on a computer display apparatus, said system comprising:

• a host computer for displaying said cursor in a three-dimensional environment displayed on said computer display apparatus, said position of said cursor in said three-dimensional environment being derived from locative data received by said host computer;
• an interface apparatus for allowing a user to manually manipulate a probe within a three dimensional volume while reporting said locative data to said host computer, wherein said host computer tracks a position of said probe within said volume using said locative data, and wherein said probe is movable in at least five degrees of freedom with respect to a fixed surface, and wherein user control of said probe in three-dimensional space controls motion of cursor in said three-dimensional environment on said computer display apparatus;
• a movable linkage including a first, second, and third joint configuration, wherein said first joint configuration couples said probe to a first link member and allows said probe to move in two degrees of freedom of rotation with respect to said first link member, said second joint configuration couples said first link member to a second link member and allows rotation of said first link member with respect to said second link member, and said third joint configuration couples said second link member to a support base and allows said second link member to move in two degrees of freedom of rotation with respect to said fixed surface;
• one or more sensors associated with each of said first, second, and third joint configurations, wherein each of said sensors measures the rotation of a degree of freedom allowed by said joint configuration;
• and
• a microprocessor, separate from said host computer system, for reading locative data from said sensors and reporting a representation of said locative data to said host computer, wherein said host computer manipulates a displayed location of said cursor in response to said reported data, wherein said microprocessor receives, decodes, and responds to high level host commands sent from said host computer, said high level host commands including requests to report data and requests to modify parameters stored within memory local to said microprocessor and separate from said host computer.