Real-time vision system and control algorithm for a spherical motor

• US 5,416,392 A
• Filed: 09/10/1993
• Issued: 05/16/1995
• Est. Priority Date: 12/18/1992
• Status: Expired due to Fees

• Current Assignee: Georgia Tech Research Corporation (University System of Georgia)
• Original Assignee: Georgia Tech Research Corporation (University System of Georgia)
• Inventors: Lee, Kok-Meng, Pao, Tsang-Long, Blenis, Robert S.
• Primary Examiner(s): IP, SHIK LUEN PAUL
• Application Number:
  US08/120,168
• Time in Patent Office: 613 Days
• Field of Search: 318/560-646, 318/37, 318/115, 318/649, 358/139, 358/163, 358/168, 358/169, 358/903, 358/113, 358/104, 358/209, 358/108, 358/87, 382/41, 382/49, 382/47, 382/8, 382/18, 382/50, 382/45, 382/48, 310/323, 310/317, 310/316, 310/328, 310/12, 901/1, 901/3, 901/5, 901/7, 901/12, 901/13, 901/14, 901/15-23, 250/229, 250/221, 250/211 K
• US Class Current: 318/568.1
• CPC Class Codes: B25J 17/0275 Universal joints, e.g. Hooke, Cardan, ball joints
• CPC Class Codes: B25J 9/126 Rotary actuators
• CPC Class Codes: H02K 2201/18 Machines moving with multiple degrees of freedom
• CPC Class Codes: H02K 41/02 Linear motors; Sectional motors
• CPC Class Codes: H02P 25/08 Reluctance motors

Abstract

A spherical motor (10) provides smooth isotropic motion. The spherical motor (10) has a spherical stator (12) surrounding a spherical rotor (18) . A motor shaft (24) is mounted to the rotor (18), or alternatively, to the stator (12) for performing work in isotropic motion. A grid pattern is situated to move substantially concentrically with the rotor (18) and in conjunction with the motor shaft (24). A vision system (80) monitors the grid pattern (42) and determines in real time the position of the motor shaft (24). The vision system (80) has at least one image sensor (44) positioned on the stator (12) and a computer system (82) for processing data independent of a remote host computer (122). Further, a motor controller (191) using a motor control algorithm (200) my be interfaced with the vision system (80) to thereby derive a motor control system (190) for controlling the spherical motor (10) based upon the rotor orientation information retrieved by the vision system (80). Finally, a video controller (106) can be interfaced with the vision system (80) for converting digital image data in real time to analog image data conforming to the (RS-170 television standard for viewing on a display device (116).

Claims

1. A method for permitting real time processing of images, comprising the steps of:

viewing an object with an image sensor for capturing an image frame;

scanning said image frame having said object;

ascertaining an approximate area defined by rows and columns of said image frame where said object is located; and

processing in real time said area, without prior storage of said image frame and said area, and discarding the remainder of said image frame;

determining a three-dimensional location of a position of a spherical body;

moving a grid pattern substantially concentrically with said spherical body;

retrieving an image of said lines of said grid pattern with an image sensor; and

determining a three dimensional orientation of said spherical body in a three dimensional reference frame comprising said image sensor based upon said image of said lines.

2. The method of claim 1, further comprising the step of converting said area to an RS-170 standard signal after said processing and discarding steps.

3. A system for permitting real time processing of images, comprising:

an image sensor for capturing an image frame of an object; and

processing means for scanning said image frame having said object for ascertaining an approximate area defined by rows and columns of said image frame where said object is located, and for processing said area, without prior storage of said image frame and said area, and discarding the remainder of said image frame;

said system further comprising;

a spherical body;

a grid pattern of lines substantially concentric with said spherical body and moveable therewith;

said image sensor for retrieving an image of said lines of said grid pattern; and

said processing means for determining a three dimensional orientation of said spherical body in a three dimensional reference frame comprising said image sensor based upon said image of said lines.

4. The system of claim 3, further comprising another image sensor in communication with said processing means and wherein said processing means processes another area of another object concurrently with the processing of said area of said object.

5. The system of claim 3, further comprising a video controller means for converting said area to an RS-170 standard signal.

6. The system of claim 3, wherein said spherical body comprises a spherical motor connected to said processing means.

7. The system of claim 3, wherein said frame is processed at a rate greater than 30 frames per second.

8. An orientation sensing system for permitting non-contact three-dimensional orientation measurement of a spherical body, comprising:

a grid pattern of lines substantially concentric with said spherical body and movable therewith;

an image sensor for capturing an image frame of said lines of said grid pattern; and

processing means associated with said image sensor, said processing means for scanning said image frame having said lines, said processing means for ascertaining as approximate area defined by rows and columns of said image frame where said lines are located, said processing means for determining a three-dimensional orientation of said spherical body in a three-dimensional reference frame comprising said image sensor based upon said image frame of said lines by processing in real time said area without prior storage of said image frame and said area, and by discarding the remainder of said image frame.

9. The system of claim 8, wherein said spherical body is a rotor in a spherical motor.

10. The system of claim 8, wherein said spherical body is the stater of a spherical motor.

11. The system of claim 8, further comprising another sensor for generating another area which is processed by said processing means in order to determine said three-dimensional orientation of said spherical body.

12. The system of claim 8, further comprising a video controller for converting said area to a RS-170 standard signal.

13. A method for permitting real time processing of images;

comprising the steps of;

viewing an object with an image sensor for capturing an image frame;

scanning said image frame having said object;

ascertaining an approximate area defined by rows and columns of said image frame where said object is located; and

,

processing in real time said area, without prior storage of said image frame and said area, and discarding the remainder of said image frame;

determining a three-dimensional location of a position on a spherical body;

moving a grid pattern substantially concentrically with said spherical body; and

determining said position of said body in three dimensional space based upon said area, said area comprising a part of said grid pattern.

14. A method for permitting real time processing of images comprising the steps of:

viewing an object with an image sensor for capturing an image frame;

scanning said image frame having said object;

ascertaining an approximate area defined by rows and columns of said image frame where said object is located; and

processing in real time said area, without prior storage of said image frame and said area, and discarding the remainder of said image frame;

determining a three-dimensional location of a position of a spherical body;

moving a grid pattern substantially concentrically with said spherical body, said grid pattern having first lines converging toward a point and having substantially parallel second lines which are substantially orthogonal to said first lines;

retrieving in said area with an image sensor a first line and at least two second lines which intersect with said first line; and

determining said position of said body in three-dimensional space based upon said area.

15. The method of claim 14, further comprising the steps of:

retrieving a second area of another first line and another set of second lines; and

determining said position of said body based upon both said first and second areas.