From Adaptive Inverse Control

10.6 A MIMO CONTROL AND SIGNAL PROCESSING EXAMPLE

An extraordinary problem of great current interest is that of canceling noise in the passenger compartment of commercial aircraft. A new generation of airplanes is being developed using a combination of turbojet engines and propellers that promises to be 30 to 40 percent more fuel efficient than the best turbojet airplanes flying in the mid 1990s. The engines and pusher propellers will most likely be mounted at the tail. A serious drawback is the increase in cabin noise resulting from the use of propellers. We propose to utilize adaptive inverse control systems of the MIMO type to control and cancel noise due to the turbojet engines and the propellers.

Referring to Fig. 10.22(a), we see the aircraft with a turbine-driven propeller at the rear. We assume that there will be two engines and two propellers, and that they will be synchronized. Thus, obtaining a single reference signal from a sensor on the shaft of one of the engines should be sufficient. We will need to obtain signals corresponding to the fundamental and harmonics of the turbine blades, and the fundamental and harmonics of the propeller blades. A single reference signal containing a...


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Topics of Interest

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