Apparatus for teaching and transforming noncoincident coordinate systems

• US 4,456,961 A
• Filed: 03/05/1982
• Issued: 06/26/1984
• Est. Priority Date: 03/05/1982
• Status: Expired due to Fees

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Price, Robert B., Jones, David L.
• Primary Examiner(s): Smith, Jerry
• Assistant Examiner(s): MACDONALD, ALLEN R
• Application Number:
  US06/355,077
• Time in Patent Office: 844 Days
• Field of Search: 364/191, 364/192, 364/193, 364/513, 364/571, 364/478, 318/568
• US Class Current: 700/251
• CPC Class Codes: B25J 9/1697 Vision controlled systems
• CPC Class Codes: G05B 19/425 Teaching successive positions by numerical control, i.e. commands being entered to control the positioning servo of the tool head or end effector
• CPC Class Codes: G05B 2219/33263 Conversion, transformation of coordinates, cartesian or polar
• CPC Class Codes: G05B 2219/36503 Adapt program to real coordinates, software orientation
• CPC Class Codes: G05B 2219/37572 Camera, tv, vision
• CPC Class Codes: G05B 2219/39002 Move tip of arm on straight line
• CPC Class Codes: G05B 2219/45083 Manipulators, robot

Abstract

A coordinate system transformation control system for a programmable manipulator having a base referenced by a three dimensional cartesian coordinate system (base frame) includes a hand-held application module for directing the operation of the programmable manipulator. The end effector of the manipulator may be moved to locate a point of origin, a point in the x axis and a point in the x-y plane of another three dimensional cartesian coordinate system (user frame). Other user frames may be selected in the same manner and one user frame may be referenced to another user frame through a mathematical operation. These are known as stacked user frames, all such frames being ultimately referred back to the base frame for operation of the programmable manipulator.

Claims

1. A coordinate system transformation control apparatus for a programmable manipulator having a base referenced by a three dimensional cartesian coordinate system (base frame), actuating means, and end effector, and motive means responsive to the actuating means for causing desired motion of the end effector, comprising:

(a) a hand-held application module for directing the operation of the programmable manipulator, and for selecting a teaching mode;

(b) means, responsive to the teaching mode, for recognizing the point of origin, a point in the X axis and a point in the X-Y plane of at least one other three dimension cartesian coordinate system (user frame

     1) as identified by three positions of the end effector;

(c) means for receiving the user frame 1 coordinates and for transforming the user frame 1 coordinates to the base frame coordinates whereby the end effector moves within the user frame in base frame coordinates; and

(d) means for initiating the actuating means to cause the motive means to move the end effector.

2. The apparatus of claim 1 wherein at least a second user frame (user frame 2) is defined and its coordinates transformed to the base frame coordinates.

3. The apparatus of claim 2 further comprising means for transforming the user frame 2 coordinates to the user frame 1 coordinates, whereby the end effector moves within the user frame 2 in base frame coordinates.

4. The apparatus of claim 1 wherein the means for transforming conforms to the matrix expression:

space="preserve" listing-type="equation">T(F.sub.b,F.sub.1),

wherein T is transformation, F_b is the representation of the base frame and F₁ is the representation of the user frame 1.

5. The apparatus of claim 4, wherein the means for transforming the user frame 2 into the user frame 1 conform to the expression:

space="preserve" listing-type="equation">T(F.sub.1,F.sub.2)=T(F.sub.b,F.sub.1).sup.-1 *T(F.sub.b,F.sub.2)

where F₂ is the representation of user frame 2.