Propeller Aircraft Noise Reduction Simulation And Experimental Research Based On Synchrophasing Control

At present,the propeller aircraft has been widely applied in virtue of for its high efficiency and large thrust,but the large noise causes many adverse influences on airborne passengers and airborne equipment.Propeller synchrophasing control,which utilizes the existing sound sources canceling each other out,is a potential active noise control method,because it can be realized on by engine electronic controller without additional weight of EEC,and without increasement of aircraft body weight.Simulation and experimental research on synchrophasing control noise reduction was carried out in this thesis.Firstly,the noise reduction principle of synchrophasing control was introduced.The general scheme of noise reduction system using synchrophasing control was improved based on the analysis of the original system.Slave-slave strategy was selected for synchrophasing control.A method using virtual phase angle was presented to eliminate large fluctuation.An improved method of resisting saturation of integral was put forward and output limits in speed control and phase angle control were designed respectively to coordinate the relationship between speed control and phase angle control,which decreased phase angle jitter effectively.Secondly,both the necessity of establishing a ground experiment platform and the accuracy requirement of synchrophasing control were analyzed,on this basis,the general scheme of ground experiment platform was put forward.The FOC control was adopted to improve the accuracy of speed control,and the encoder sensor was selected to measure phase angle.A ground monitoring software and a data playback software for the synchrophasing control system were designed.Control parameters were tuned.Experiment results indicated that the error of synchrophasing control was less than 3°.Finally,the flight verification of synchrophasing control was carried out.A flight platform based on a small unmanned aerial vehicle was established.The general scheme of flight experiment was presented based on the subsystem design of flight control system,power system,and other systems.The flight control system was regulated to a good condition during the field experiment.The comparison of various phase angle difference in flight experiment verified the effectiveness of noise reduction.