System and method of interactive evaluation of a geometric model

• US 7,155,673 B2
• Filed: 02/01/2001
• Issued: 12/26/2006
• Est. Priority Date: 02/01/2001
• Status: Expired due to Fees

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Chen, Yifan, Stewart, Paul Joseph, Buttolo, Pietro
• Primary Examiner(s): Lefkowitz, Sumati
• Assistant Examiner(s): Kumar, Srilakshmi K
• Application Number:
  US09/775,368
• Publication Number:
  US 20020101400A1
• Time in Patent Office: 2,154 Days
• Field of Search: 345156-179, 345700-702, 715/701
• US Class Current: 715/701
• CPC Class Codes: G06F 3/016 Input arrangements with force or tactile feedback as computer generated output to the user

Abstract

A system and method of interactive evaluation of a geometric model is provided. The method includes the steps of acquiring a haptic device position and orientation with respect to a surface of the geometric model and mapping the haptic device position and orientation into a geometric model coordinate reference system. The method also includes the steps of determining a closest point position and orientation on the surface of the geometric model to the haptic device position and extracting a surface property at the closest point position and orientation. The method further includes the steps of determining a stick-to-surface force and a property feedback force using the surface property at the closet point position and orientation and applying the stick-to-surface force and property feedback force to control a location and force output of the haptic device.

Claims

1. A system of interactive evaluation of a geometric model comprising:

a computer system including a memory, a processor, a user input device, and a display device;

a computer generated geometric model stored in said memory of said computer system; and

a haptic interface operatively in communication with said computer system, wherein said haptic interface includes a haptic device for transmitting information between a user and the geometric model and wherein a haptic device position and orientation are acquired with respect to a surface of said geometric model and mapped into a geometric model coordinate reference system, a closest point position and orientation on the surface of said geometric model to the haptic device position is determined, a surface property of said geometric model at the closest point position and orientation is extracted, and a stick-to-surface force and a property-feedback force are determined and applied to said haptic device to constrain a motion of said haptic device to stick and be orientated normal to a virtual surface representing the surface of said geometric model, thereby constraining a hand of a user to always be on the surface to enable the user to explore and feel the geometric model.

2. A system as set forth in claim 1 including a virtual reality display mechanism operatively in communication with said computer system and said haptic interface, so the user can see the geometric model in a virtual environment.

3. A system as set forth in claim 1 wherein said haptic interface tactilely conveys a surface property of the geometric model to a user through said haptic device and said haptic device is constrained to the surface of the geometric model.

4. A method of interactive evaluation of a geometric model, said method comprising the steps of:

acquiring a haptic device position and orientation with respect to a surface of the geometric model, wherein the haptic device is operatively connected to a haptic interface and the geometric model is stored in a memory of a computer system;

mapping the haptic device position and orientation into a geometric model coordinate reference system;

determining a closest point position and orientation on the surface of the geometric model to the haptic device position;

extracting a surface property at the closest point position and orientation;

determining a stick-to-surface force and a property feedback force using the surface property of the geometric model at the closet point position and orientation; and

applying the stick-to-surface force and property feedback force to the haptic device to constrain a motion of the haptic device to stick and be orientated normal to a virtual surface representing the surface of the geometric model, thereby constraining a hand of a user to always be on the surface to enable the user to explore and feel the geometric model.

5. A method as set forth in claim 4 including the step of selecting a geometric model from a database in the memory of the computer system prior to said step of acquiring the haptic device position and orientation, wherein the geometric model is a computer-aided design model.

6. A method as set for in claim 5 including the step of configuring the geometric model as a parametric surface, wherein a point representing the model has a set of coordinates within a predetermined coordinate system.

7. A method as set forth in claim 6 including the step of orienting a haptic device position within a haptic device coordinate system.

8. A method as set forth in claim 4 wherein said step of extracting a surface property includes the step of determining a surface normal at the closest point position and orientation.

9. A method as set forth in claim 4 wherein said step of extracting a surface property includes the step of determining a surface curvature at the closest point position and orientation.

10. A method as set forth in claim 4 including the step of mapping the surface property of the closest point position and orientation into a vector after said step of extracting a surface property.

11. A method as set forth in claim 10 including the step of mapping the surface property of the closest point position and orientation into the haptic device coordinate reference system.

12. A method as set forth in claim 4 wherein said step of applying a stick-to-surface force and a property feedback force includes the step of tactilely conveying a surface property of the geometric model to a user through the haptic device and constraining the haptic device to the surface of the geometric model.

13. A method as set forth in claim 4 wherein the user views the surface of the geometric model using a virtual reality display mechanism in communication with the computer system and the haptic interface.

14. A method as set forth in claim 13 wherein the computer system, haptic interface and virtual reality display mechanism are in communication with each other.

15. A method of interactive evaluation of a geometric model, said method comprising the steps of:

selecting a geometric model from a database in the memory of a computer system;

acquiring a haptic device position and orientation with respect to a surface of the geometric model, wherein the haptic device is operatively connected to a haptic interface;

mapping the haptic device position and orientation into a geometric model coordinate reference system;

determining a closest point position and orientation on the surface of the geometric model to the haptic device position;

extracting a surface property at the closest point position and orientation;

mapping the surface property of the closest point position and orientation into a vector;

mapping the surface property of the closest point position and orientation into the haptic device coordinate reference system;

determining a stick-to-surface force and a property feedback force using the surface property of the geometric model at the closet point position and orientation; and

adding the stick-to-surface force and property feedback force together to form an applied force and applying the applied force to the haptic device to constrain a motion of the haptic device to stick and be orientated normal to a virtual surface representing the surface of the geometric model, thereby constraining a hand of a user to always be on the surface to enable the user to explore and feel the geometric model.

16. A method as set forth in claim 15 including the step of configuring the geometric model as a parametric surface, wherein a point representing the model has a set of coordinates within a predetermined coordinate system.

17. A method as set forth in claim 16 including the step of orienting a haptic device position within a haptic device coordinate system.

18. A method as set forth in claim 15 wherein said step of extracting a surface property includes the step of determining a surface normal at the closest point position and orientation.

19. A method as set forth in claim 15 wherein said step of extracting a surface property includes the step of determining a surface curvature at the closest point position and orientation.

20. A method as set forth in claim 15 wherein the user views the surface of the geometric model using a virtual reality display mechanism in communication with the computer system and the haptic interface.