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US 5,568,557 AGranted
Active vibration control system for aircraft
AssigneeNoise Cancellation Technologies, Inc.
InventorsColin F. Ross, Andrew J. Langley
Life of this patent
Estimating the term…
Abstract
An active noise and vibration reduction system for canceling noise in aircraft or other passenger carrying transportation systems which utilizes a series of seat mounted microphones and trim mounted speakers in conjunction with a digital controller with a class-D stage power amplifier and which is synched to the aircraft alternator.
Claims13
An active control system for reducing the tonal vibration in the cabin of an aircraft, helicopter or other passenger carrying cabin comprising:
- individual power amplifier means,
- actuator means combined with said individual power amplifier means and adapted to produce an additional vibration field,
- trim-mounted sensing means adapted to generate signals responsive to sound in the cabin and insensitive to sound between the trim and the outer skin of the vehicle, and
- a controller means responsive to the said sensing means signals and adapted to adjust signals to the said actuator means so that the said additional vibration field tends to reduce the said cabin vibration,
- said controller means characterized in that it receives its speed reference signal from a power alternator on said vehicle and that the said power amplifier means contains an efficient class-D stage and wherein the said controller means monitors its own performance and switches off when the said monitored performance falls below a prescribed level and wherein it detects failures of the said sensing means and said actuator means.
2 more elements
Dependencies are inferred from the claim text.