Method of adaptively controlling paint system

• US 6,701,193 B1
• Filed: 08/18/2000
• Issued: 03/02/2004
• Est. Priority Date: 08/18/2000
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Motor Company
• Inventors: Feldkamp, Lee Albert, Filev, Dimitar P., Larsson, Tomas, Lixing, Ma, Prokhorov, Danil Valentinovich
• Primary Examiner(s): Khatri, Anil
• Assistant Examiner(s): PHAM, THOMAS K
• Application Number:
  US09/641,738
• Time in Patent Office: 1,292 Days
• Field of Search: 700/28-32, 700/47-48, 700/123, 700/263, 427/421, 427/424, 427/427, 427/435, 427/443.2
• US Class Current: 700/28
• CPC Class Codes: B05B 12/12 responsive to conditions of ambient medium or target, e.g. humidity, temperature position or movement of the target relative to the spray apparatus B05B12/082, B05B12/084 take precedence
• CPC Class Codes: G05B 13/042 in which a parameter or coefficient is automatically adjusted to optimise the performance

Abstract

A method is provided of adaptively controlling a paint system for painting vehicle bodies. The method includes the steps of obtaining an estimated Jacobian that identifies characteristics of the paint system and using the estimated Jacobian to determine initial conditions to be implemented for the next vehicle body to be painted in the paint system. The method also includes the steps of storing a database of appropriate initial conditions that resulted in satisfactory transient response in a rule-base and using the rule-base at start-up of the paint system or if the paint system fails to be satisfactorily controlled.

Claims

1. A method of adaptively controlling a paint system for painting vehicle bodies, said method comprising the steps of:

obtaining an estimated Jacobian that identifies characteristics of the paint system;

using the estimated Jacobian to determine control parameters to be implemented for the next vehicle body to be painted in the paint system;

storing a database of appropriate initial conditions that resulted in satisfactory transient response in a rule-base; and

using the rule-base at start-up of the paint system or if the paint system fails to be satisfactorily controlled.

2. A method as set forth in claim 1 wherein said step of obtaining comprises obtaining an estimated Jacobian using a linear estimation that identifies characteristics of the paint system.

3. A method as set forth in claim 1 including the step of using a Smith predictor to compensate for a measurement delay between output and input of the paint system.

4. A method as set forth in claim 1 including the step of solving a constrained optimization problem using the estimated Jacobian to determine an optimal change in control parameters to be implemented for the next vehicle body to be painted in the paint system.

5. A method as set forth in claim 1 including the step of storing environmental variables in the rule-base.

6. A method as set forth in claim 1 wherein the control variables include paint flow and shaping air.

7. A method as set forth in claim 5 including the step of using the environmental variables to determine a new set of initial conditions for the paint system.

8. A method as set forth in claim 5 wherein the environmental variables include paint temperature, humidity, and down draft.

9. A method of adaptively controlling a paint system for painting vehicle bodies, said method comprising the steps of:

obtaining an estimated Jacobian that identifies characteristics of the paint system;

solving a constrained optimization problem using the estimated Jacobian to determine an optimal change in control parameters to be implemented for the next vehicle body to be painted in the paint system; and

using the optimal change in control parameters to control the paint system.

10. A method as set forth in claim 9 including the step of storing a database of appropriate initial conditions that resulted in satisfactory transient response in a rule-base.

11. A method as set forth in claim 10 including the step of using the rule-base at start-up of the paint system or if the paint system fails to be satisfactorily controlled.

12. A method as set forth in claim 9 wherein said step of obtaining comprises obtaining an estimated Jacobian using a linear estimation that identifies characteristics of the paint system.

13. A method as set forth in claim 9 including the step of using a Smith predictor to compensate for a measurement delay between output and input of the paint system.

14. A method as set forth in claim 9 including the step of storing environmental variables in the rule-base and using the environmental variables to determine a new set of initial conditions for the paint system.

15. A method of adaptively controlling a paint system for painting vehicle bodies, said method comprising the steps of:

obtaining an estimated Jacobian that identifies characteristics of the paint system;

using the estimated Jacobian to determine initial conditions to be implemented for the next vehicle body to be painted in the paint system;

using the initial conditions to control the paint system; and

using a Smith predictor to compensate for a measurement delay between output and input of the paint system.

16. A method as set forth in claim 15 wherein said step of obtaining comprises obtaining an estimated Jacobian using Kalman filter estimation that identifies characteristics of the paint system.

17. A method as set forth in claim 15 including the step of storing a database of appropriate initial conditions that resulted in satisfactory transient response in a rule-base.

18. A method as set forth in claim 15 including the step of solving a constrained optimization problem using the estimated Jacobian to determine an optimal change in control parameters to be implemented for the next vehicle body to be painted in the paint system.

19. A method as set forth in claim 15 including the step of storing environmental variables in the rule-base and using the environmental variables to determine a new set of initial conditions for the paint system.

20. A method as set forth in claim 17 including the step of using the rule-base at start-up of the paint system or if the paint system fails to be satisfactorily controlled.