Optimal Active Sound-Reduction in Airplane-Cubicles for High Tonal Noise-Levels (optimale aktive gerauschreduzierung in flugzeugkabinen fur hohe tonale larmpegel)

摘要

With the procedures presented in this work it is possible to lay an active noise reduction system out for high tonal noise levels. The FxLMS algorithm well-known from the literature is adapted according to the requirements. It is appropriate now to regulate both several load cases and base positions. The regulation success which can be obtained can be adjusted. Thus with high noise levels considered the high actuator controls then can be expected. The operability of the regulation algorithm is experimentally proven. For the position optimization of actuators and sensors a new procedure for the cost determination of data for an individual configuration is presented. This procedure is characterised by the fact that it considers not only the obtained regulation success, but also the electrical achievement necessary for it similarly to the rule algorithm. The cost determination of data is merged into COSA procedures well-known from the literature. The positions determined with this procedure are experimentally verified. It shows up that the determined positions can serve as basis for an experimental optimization. This experimental optimization can be simplified by the numeric procedure, not replaced however. In the literature so far no position optimization for the active noise reduction is presented into half-closed volume. This gap is closed with the available work. Due to the special conditions with a half-closed volume a special arrangement of the actuators is selected. This arrangement is announced in Breitbach to the patent. Both the numeric and the experimental investigations clarity that a local control system is suitable with changing base positions and flight conditions also.