Shock, vibration and acoustic isolation system

• US 6,923,298 B2
• Filed: 05/20/2004
• Issued: 08/02/2005
• Est. Priority Date: 09/27/2001
• Status: Expired due to Fees

• Current Assignee: Huntington Ingalls, Inc. (Huntington Ingalls Industries Incorporated)
• Original Assignee: Northrop Grumman Corporation
• Inventors: Tanner, Edward T.
• Primary Examiner(s): SICONOLFI, ROBERT
• Application Number:
  US10/850,209
• Publication Number:
  US 20040212132A1
• Time in Patent Office: 439 Days
• Field of Search: 188/267, 188/267.1, 188/267.2, 267 6411- 6428, 267/136, 267/131, 267/140.14, 267/140.15
• US Class Current: 188/267
• CPC Class Codes: B60G 13/14 having dampers accumulating utilisable energy, e.g. compressing air fluid springs with an accumulator B60G11/30
• CPC Class Codes: B60G 17/08 Characteristics of fluid dampers adjusting fluid dampers in general F16F9/44 - F16F9/53
• CPC Class Codes: B60G 2202/314 The spring being a pneumatic spring
• CPC Class Codes: F16F 15/022 using dampers and springs in combination
• CPC Class Codes: F16F 2224/043 electrorheological
• CPC Class Codes: F16F 2224/045 magnetorheological
• CPC Class Codes: F16F 2230/18 Control arrangements
• CPC Class Codes: F16F 9/05 the flexible wall being of the rolling diaphragm type

Abstract

A shock and vibration isolation system for mounting equipment to a base wall uses a semi-active damper in parallel with a spring arrangement to provide optimum isolation with respect to both shock and vibration. The system comprises a load plate configured for attachment of the equipment thereto and a base plate configured for attachment to the base wall. The base plate is substantially parallel to the load plate with a spring arrangement disposed intermediate the load plate and the base plate. The spring arrangement engages the load plate and the base plate to bias the load plate and the base plate in a separated relationship. The system also comprises a damping arrangement disposed intermediate the load plate and the base plate. The damping arrangement is adapted for providing a selectively variable reaction force to the load plate and the base plate responsive to a relative displacement of the load plate with respect to the base plate.

Claims

1. A shock and vibration isolation system for mounting equipment to a base wall, the system comprising:

a load plate configured for attachment of the equipment thereto;

a base plate configured for attachment to the base wall;

the base plate being substantially parallel to the load plate;

a spring arrangement disposed intermediate the load plate and the base plate, the spring arrangement engaging the load plate and the base plate to bias the load plate and the base plate in a separated relationship;

at least one semi-active damper operatively connected to the load plate and the base plate for providing a selectively variable reaction force to the load plate and the base plate responsive to a relative displacement of the load plate with respect to the base plate; and

an adaptive damper controller operatively connected to the at least one semi-active damper for controlling the reaction force applied to the load plate and the base plate, the damper controller including an optimum damper force determination module programmed for calculating an optimum reaction force F_Opt using the equation

F_Opt=G₁X_Rel+G₂ V_Rel

 

where X_Rel is the relative displacement between the load plate and the base plate, V_Rel is the velocity of the load plate relative to base plate, G₁ is a first gain value and G₂ is a second gain value, the optimum damper force determining module being further programmed for calculating the first and second gain values based on an optimizable cost function.

2. An isolation system according to claim 1 wherein the at least one semi-active damper is a magnetorheological fluid damper.

3. An isolation system according to claim 1 wherein the at least one semi-active damper is an electrorheological fluid damper.

4. An isolation system according to claim 1 wherein the controller further includes

a current driver operatively connected to the at least one semi-active damper for selectively supplying current to energize the at least one semi-active damper;

a damper force control module in communication with the optimum force determination module and the current driver, the damper force control module being adapted for controlling the supply of current to the at least one semi-active damper according to a predetermined control algorithm.

5. An isolation system according to claim 4 wherein the control algorithm is selected from the group consisting of clipped optimal control, Lyapunov stability theory, decentralized bang-bang control, and modulated homogeneous friction control.

6. An isolation system according to claim 1 wherein the optimum reaction force determination module comprises a programmable digital processor having optimum force determination software configured for calculating the first and second gains and the optimum reaction force.

7. An isolation system according to claim 6 wherein the programmable digital processor has gain adjustment software configured for determining a change in mass of the equipment based on a change in steady state spacing between the load plate and the base plate and for adjusting at least one of the first and second gains based on the determined change in mass.

8. An isolation system according to claim 1 wherein the optimum force determination module comprises field replaceable analog circuitry adapted for providing the optimum reaction force using the first and second gains.

9. An isolation system according to claim 1 wherein the damping arrangement includes a power supply operatively connected to the at least one semi-active damper.

10. An isolation system according to claim 9 wherein the power supply is included in the damper controller.

11. An isolation system according to claim 9 wherein the power supply is rechargeable, the system further comprising a recharging arrangement in electrical communication with the rechargeable power supply, the recharging arrangement being attached to one of the base plate and the load plate and having means for converting vibratory motion to electrical energy for storage in the rechargeable power supply.

12. An isolation system according to claim 11 wherein the means for converting includes an electrical coil, at least one spring and a magnet connected to the at least one spring, the magnet being disposed within the electrical coil so that oscillation of the magnet produces a current in the electrical coil.

13. An isolation system according to claim 1 wherein the spring arrangement has a natural frequency in a range from about 1.0 Hz. to about 10.0 Hz.

14. An isolation system according to claim 1 wherein the spring arrangement includes at least one pneumatic spring.

15. A shock and vibration isolation system for mounting equipment to a base wall, the system comprising:

a load plate configured for attachment of the equipment thereto;

a base plate configured for attachment to the base wall;

the base plate being substantially parallel to the load plate;

a spring arrangement disposed intermediate the load plate and the base plate, the spring arrangement engaging the load plate and the base plate to bias the load plate and the base plate in a separated relationship;

damping means for providing a selectively variable reaction force to the load plate and the base plate responsive to a relative displacement of the load plate with respect to the base plate, the damping means being disposed intermediate the load plate and the base plate; and

adaptive controller means for controlling the reaction force applied to the load plate and the base plate, the controller means being operatively connected to the damping means and including means for calculating an optimum reaction force F_Opt using the equation

F_Opt=G₁X_Rel+G₂V_Rel

 

where X_Rel is the relative displacement between the load plate and the base plate, V_Rel is the velocity of the load plate relative to base plate, G₁ is a first gain value and G₂ is a second gain value, the means for calculating an optimum reaction force being adapted for calculating the first and second gain values based on an optimizable cost function.

16. An isolation system according to claim 15 wherein the damping means includes at least one semi-active damper operatively connected to the base plate and the load plate.

17. An isolation system according to claim 16 wherein the at least one semi-active damper is a magnetorheological fluid damper.

18. An isolation system according to claim 16 wherein the at least one semi-active damper is an electrorheological fluid damper.

19. An isolation system according to claim 16 wherein the controller means further includes

means for selectively supplying current to energize the semi-active damper;

and

means for controlling the supply of current to the semi-active damper according to a predetermined control algorithm, the means for controlling the supply of current being in communication with the means for selectively supplying current and the means for calculating an optimum reaction force.

20. An isolation system according to claim 19 wherein the control algorithm is selected from the group consisting of clipped optimal control, Lyapunov stability theory, decentralized bang-bang control, and modulated homogeneous friction control.

21. An isolation system according to claim 15 wherein the means for calculating an optimum reaction force comprises a programmable digital processor having optimum force determination software configured for calculating the first and second gains and the optimum reaction force.

22. An isolation system according to claim 21 wherein the programmable digital processor has gain adjustment software configured for determining a change in mass of the equipment based on a change in steady state spacing between the load plate and the base plate and for adjusting at least one of the first and second gains based on the determined change in mass.

23. An isolation system according to claim 15 wherein the means for calculating an optimum reaction force comprises field replaceable analog circuitry adapted for providing the optimum reaction force using the first and second gains.

24. An isolation system according to claim 16 wherein the damping means includes a power supply operatively connected to the at least one semi-active damper.

25. An isolation system according to claim 24 wherein the power supply is rechargeable, the system further comprising means for recharging the rechargeable power supply, the means for recharging being attached to one of the base plate and the load plate and having means for converting vibratory motion to electrical energy for storage in the rechargeable power supply.

26. An isolation system according to claim 25 wherein the means for converting includes an electrical coil, at least one spring and a magnet connected to the at least one spring, the magnet being disposed within the electrical coil so that oscillation of the magnet produces a current in the electrical coil.

27. An isolation system according to claim 15 wherein the spring arrangement has a natural frequency in a range from about 1.0 Hz. to about 10.0 Hz.

28. An isolation system according to claim 15 wherein the spring arrangement includes at least one pneumatic spring.

29. A shock and vibration isolation system for mounting equipment to a base wall, the system comprising:

a load plate configured for attachment of the equipment thereto;

a base plate configured for attachment to the base wall;

the base plate being substantially parallel to the load plate;

a spring arrangement disposed intermediate the load plate and the base plate, the spring arrangement engaging the load plate and the base plate to bias the load plate and the base plate in a separated relationship;

at least one magnetorheological fluid damper disposed intermediate the load plate and the base plate, the a magnetorheological fluid damper being adapted for providing a selectively variable reaction force to the load plate and the base plate responsive to a relative displacement of the load plate with respect to the base plate; and

an adaptive damper controller operatively connected to the at least one magnetorheological fluid damper for controlling the reaction force applied to the load plate and the base plate, the damper controller including an optimum damper force determination module programmed for calculating an optimum reaction force F_Opt using the equation

F_Opt=G₁X_Rel+G₂V_Rel

 

where X_Rel is the relative displacement between the load plate and the base plate, V_Rel is the velocity of the load plate relative to base plate, G₁ is a first gain value and G₂ is a second gain value, the optimum damper force determination module being further programmed for calculating the first and second values based on an optimizable cost function.

30. An isolation system according to claim 29 wherein the controller further includes

a current driver operatively connected to the at least one magnetorheological fluid damper for selectively supplying current to energize the at least one magnetorheological fluid damper;

a damper force control module in communication with the optimum force determination module and the current driver, the damper force control module being adapted for controlling the supply of current to the at least one magnetorheological fluid damper according to a predetermined control algorithm.

31. An isolation system according to claim 30 wherein the control algorithm is selected from the group consisting of clipped optimal control, Lyapunov stability theory, decentralized bang-bang control, and modulated homogeneous friction control.

32. An isolation system according to claim 29 wherein the optimum reaction force determination module comprises a programmable digital processor having optimum force determination software configured for calculating the first and second gains and the optimum reaction force.

33. An isolation system according to claim 32 wherein the programmable digital processor has gain adjustment software configured for determining a change in mass of the equipment based on a change in steady state spacing between the load plate and the base plate and for adjusting at least one of the first and second gains based on the determined change in mass.

34. An isolation system according to claim 29 wherein the optimum force determination module comprises field replaceable analog circuitry adapted for providing the optimum reaction force using the first and second gains.

35. An isolation system according to claim 29 further comprising a power supply operatively connected to the at least one magnetorheological fluid damper.

36. An isolation system according to claim 35 wherein the power supply is included in the damper controller.

37. An isolation system according to claim 35 wherein the power supply is rechargeable, the system further comprising a recharging arrangement in electrical communication with the rechargeable power supply, the recharging arrangement being attached to one of the base plate and the load plate and having means for converting vibratory motion to electrical energy for storage in the rechargeable power supply.

38. An isolation system according to claim 37 wherein the means for converting includes an electrical coil, at least one spring and a magnet connected to the at least one spring, the magnet being disposed within the electrical coil so that oscillation of the magnet produces a current in the electrical coil.

39. An isolation system according to claim 29 wherein the spring arrangement has a natural frequency in a range from about 1.0 Hz. to about 10.0 Hz.

40. An isolation system according to claim 29 wherein the spring arrangement includes at least one pneumatic spring.

41. A shock and vibration isolation system for mounting equipment to a base wall, the system comprising:

a load plate configured for attachment of the equipment thereto;

a base plate configured for attachment to the base wall;

the base plate being substantially parallel to the load plate;

a spring arrangement disposed intermediate the load plate and the base plate, the spring arrangement engaging the load plate and the base plate to bias the load plate and the base plate in a separated relationship;

at least one semi-active damper operatively connected to the base plate and the load plate for providing a selectively variable reaction force to the load plate and the base plate responsive to a relative displacement of the load plate with respect to the base plate;

a rechargeable power supply operatively connected to the at least one semi-active damper for selectively powering the at least one semi-active damper;

a recharging arrangement in electrical communication with the rechargeable power supply, the recharging arrangement being mounted to one of the base plate and the load plate and being configured for converting vibratory motion to electrical energy for storage in the rechargeable power supply; and

an adaptive damper controller operatively connected to the at least one semi-active damper for controlling the reaction force applied to the load plate and the base plate, the damper controller comprising an optimum damper force determination module configured for determining from real time data the relative displacement of the load plate and a relative velocity of the load plate with respect to the base plate, for calculating first and second gain values and for calculating an optimum reaction force from the relative displacement, the relative velocity and the first and second gain values.

42. An isolation system according to claim 41 wherein the recharging arrangement includes an electrical coil, at least one spring and a magnet connected to the at least one spring, the magnet being disposed within the electrical coil so that oscillation of the magnet produces a current in the electrical coil.

43. An isolation system according to claim 41 wherein the at least one semi-active damper is a magnetorheological fluid damper.

44. An isolation system according to claim 41 wherein the at least one semi-active damper is an electrorheological fluid damper.

45. An isolation system according to claim 41 wherein the optimum damper force determination module is programmed for calculating an optimum reaction force F_Opt using the equation

F_Opt=G₁X_Rel+G₂V_Rel

where X_Rel is the relative displacement between the load plate and the base plate, V_Rel is the velocity of the load plate relative to base plate, G₁ is the first gain value and G₂ is the second gain value, the optimum damper force determination module being further programmed for calculating the first and second gain values based on an optimizable cost function.

46. An isolation system according to claim 41 wherein the optimum force determination module includes gain adjustment software configured for determining a change in mass of the equipment based on a change in steady state spacing between the load plate and the base plate and for adjusting at least one of the first and second gains based on the determined change in mass.

47. An isolation system according to claim 41 wherein the power supply is included in the damper controller.