Pneumatic actuation control system and method of operation

• US 6,708,708 B2
• Filed: 07/25/2002
• Issued: 03/23/2004
• Est. Priority Date: 07/25/2002
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Winkler, Daniel S., Wingert, David A.
• Primary Examiner(s): Michalsky, Gerald A.
• Application Number:
  US10/205,076
• Publication Number:
  US 20040016465A1
• Time in Patent Office: 607 Days
• Field of Search: 137/12, 137/81.1, 137/596.17
• US Class Current: 137/12
• CPC Class Codes: B64C 13/48 characterised by the fluid being gaseous
• CPC Class Codes: F15B 11/028 for controlling the actuating force F15B11/024 takes precedence
• CPC Class Codes: F15B 11/08 with only one servomotor
• CPC Class Codes: F15B 21/006 Compensation or avoidance of ambient pressure variation
• CPC Class Codes: F15B 2211/30525 Directional control valves, e.g. 4/3-directional control valve
• CPC Class Codes: F15B 2211/327 electrically or electronically
• CPC Class Codes: F15B 2211/50536 using unloading valves controlling the supply pressure by diverting fluid to the return line
• CPC Class Codes: F15B 2211/50554 the pressure control means controlling a pressure downstream of the pressure control means, e.g. pressure reducing valve
• CPC Class Codes: F15B 2211/5151 being connected to a pressure source and a directional control valve
• CPC Class Codes: F15B 2211/528 actuated by fluid pressure
• CPC Class Codes: F15B 2211/55 for limiting a pressure up to a maximum pressure, e.g. by using a pressure relief valve
• CPC Class Codes: F15B 2211/89 Control specific for achieving vacuum or "negative pressure"
• CPC Class Codes: G05D 16/2013 using throttling means as controlling means
• CPC Class Codes: Y10T 137/0379 By fluid pressure
• CPC Class Codes: Y10T 137/2012 Pressure
• CPC Class Codes: Y10T 137/86622 Motor-operated
• CPC Class Codes: Y10T 137/87217 Motor

Abstract

A pneumatic actuation control system includes a pressure controller, an eductor and a valve. The pressure controller is capable of directing an amount of fluid to the contained volume such that a pressure within the contained volume exceeds a pressure external to the contained volume by a predefined positive pressure. The pressure controller can also adjust the pressure within the contained volume when the pressure external to the contained volume changes. The eductor can draw fluid from the contained volume to thereby decrease the pressure within the contained volume. The valve is controllably operable in either a pressure mode or a vacuum mode, where the valve either permits the pressure controller to provide fluid to the contained volume, or permits the eductor to draw fluid from the contained volume. As such, the system provides precision pressure control over a broad range of external pressures while compensating for rapid pressure changes.

Claims

1. A pneumatic actuation control system for controlling a pressurizable object that defines a contained volume, said system comprising:

a pressure controller capable of directing fluid flow, wherein said pressure controller is capable of directing an amount of fluid to the contained volume such that a pressure of fluid within the contained volume exceeds a pressure of fluid external to the contained volume by a predefined positive pressure, wherein said pressure controller is further capable of adjusting the pressure of fluid within the contained volume, and wherein said pressure controller is capable of adjusting the pressure by at least one of providing additional fluid to the contained volume and drawing an amount of fluid from the contained volume when the pressure external to the contained volume changes;

an eductor capable of drawing fluid from within the contained volume to thereby decrease the pressure of fluid within the contained volume; and

a valve in fluid communication with said pressure controller, said eductor and the pressurizable object, wherein said valve is controllably operable in at least one of a pressure mode and a vacuum mode, wherein when said valve operates in the pressure mode said valve permits said pressure controller to at least one of directing an amount of fluid to the contained volume and adjusting the pressure of fluid within the contained volume, and wherein when said valve operates in the vacuum mode said valve permits said eductor to draw fluid from the contained volume.

2. A pneumatic actuation control system according to claim 1, wherein when the pressure of fluid external to the contained volume increases said pressure controller is capable of adjusting the pressure of fluid within the contained volume by providing additional fluid to the contained volume, and wherein when the pressure of fluid external to the contained volume decreases said pressure controller is capable of adjusting the pressure of fluid within the contained volume by drawing an amount of fluid from the contained volume.

3. A pneumatic actuation control system according to claim 1 further comprising a fluid source in fluid communication with said pressure controller and said eductor, wherein said fluid source is capable of providing the fluid directed by said pressure controller.

4. A pneumatic actuation control system according to claim 3, wherein said fluid source is further capable of providing fluid to said eductor, and wherein said eductor is capable of receiving fluid and thereafter drawing fluid from the contained volume based upon fluid received from said fluid source.

5. A pneumatic actuation control system according to claim 4 further comprising a pressure regulator disposed between said fluid source and said pressure controller and in fluid communication with said fluid source and said pressure controller, wherein said pressure regulator is also disposed between said fluid source and said eductor and in fluid communication with said fluid source and said eductor, and wherein said pressure regulator is capable of regulating a pressure of fluid from said fluid source.

6. A pneumatic actuation control system according to claim 1, wherein said pressure controller is capable of measuring a pressure differential between the pressure of fluid within the contained volume and the pressure of fluid external to the contained volume.

7. A pneumatic actuation control system according to claim 6, wherein said pressure controller is capable of repeatedly measuring the differential pressure, wherein when the pressure of fluid external to the contained volume increases by an amount said pressure controller is capable of adjusting the pressure of fluid within the contained volume by providing additional fluid to the contained volume to thereby increase the pressure of fluid within the contained volume by the same amount, and wherein when the pressure of fluid external to the contained volume decreases by an amount said pressure controller is capable of drawing an amount of fluid from the contained volume to thereby decrease the pressure of fluid within the contained volume by the same amount.

8. A pneumatic actuation control system according to claim 1 further comprising a valve control switch capable of controlling operation of said valve.

9. A pneumatic actuation control system according to claim 1, wherein said pressure controller is capable of directing an amount of fluid to the contained volume such that the pressure of fluid within the contained volume exceeds the pressure of fluid external to the contained volume by no more than 0.1 psi.

10. A pneumatic actuation control system according to claim 1, wherein said pressure controller is capable of directing an amount of fluid to the contained volume such that the pressure of fluid within the contained volume exceeds the pressure of fluid external to the contained volume by 0.1 psi.

11. A pneumatic actuation control system according to claim 1, wherein the pressurizable object is at an altitude and the pressure of fluid external to the contained volume comprises atmospheric pressure at the altitude, wherein when the altitude of the pressurizable object changes to thereby change the atmospheric pressure said pressure controller is capable of adjusting the pressure of fluid within the contained volume based upon the change in atmospheric pressure.

12. A method of pneumatically actuating a pressurizable object that defines a contained volume, said method comprising:

determining a pressure differential between a pressure within the contained volume and a pressure external to the contained volume;

directing an amount of fluid to the contained volume such that the pressure within the contained volume exceeds the pressure external to the contained volume by a predefined positive pressure;

adjusting the pressure of fluid within the contained volume, wherein adjusting the pressure comprises at least one of providing additional fluid to the contained volume and drawing an amount of fluid from the contained volume when the pressure external to the contained volume changes; and

drawing fluid from the contained volume thereby decreasing the pressure of fluid within the contained volume.

13. A method according to claim 12, wherein the pressurizable object is at an altitude and the pressure external to the contained volume comprises atmospheric pressure at the altitude, said method further comprising altering the altitude of the pressurizable object to thereby alter the atmospheric pressure, wherein altering the altitude occurs after directing an amount of fluid to the contained volume.

14. A method according to claim 12, wherein the pressure external to the contained volume increases adjusting the pressure within the contained volume comprises providing additional fluid to the contained volume to thereby increase the pressure of fluid within the contained volume, and wherein when the pressure external to the contained volume decreases adjusting the pressure within the contained volume comprises drawing fluid from the contained volume to thereby decrease the pressure of fluid within the contained volume.

15. A method according to claim 12, wherein directing an amount of fluid to the contained volume comprises directing an amount of fluid to the contained volume such that the pressure within the contained volume exceeds the pressure external to the contained volume by no more than 0.1 psi.

16. A method according to claim 12, directing an amount of fluid to the contained volume comprises directing an amount of fluid to the contained volume such that the pressure within the contained volume exceeds the pressure external to the contained volume by 0.1 psi.