Research On Active Control For Vehicle Interior Noise Based On Piezoelectric Effect

With the rapid development of vehicle industry,people paid more attention to not only the dynamic performance,but also the riding comfort of a vehicle.The low frequency vibration generated by the walls and plates of a running vehicle may cause structural noise and propagate to the interior cavity,which affects the passenger's comfort and driving safety.Thus,in this thesis,the plate vibration control of vehicle body is carried out by using the piezoelectric material and fuzzy control method.Firstly,based on the electromechanical coupling characteristics of the piezoelectric materials,the positive and inverse mechanism is studied and four piezoelectric constitutive equations are deduced.The analytical model of a piezoelectric intelligent plate is built by impedance analysis method.The size of the piezoelectric ceramic actuator is determined by analyzing its bending moment state.The driving equation of the piezoelectric material used as an actuator is derived and the sticking positions of sensor and actuator on a piezoelectric ceramic strip are determined.The modal analysis,dynamic response analysis and interior sound field analysis of a cavity model are performed for obtaining reasonable positions of piezoelectric actuator,which is a theoretical basis for active vibration control.Secondly,a fuzzy controller for active vibration control is designed and simulated.The fuzzy control algorithm is improved by adjusting the quantization factors,such as the deviation and deviation rate.For training the controller,the vibration response signals are directly extracted from the structure and quickly fed to the algorithm inference process.Based on the derived piezoelectric equations and the improved fuzzy algorithm,an active noise control(ANC)system is developed and analyzed by simulations.The result shows that the active controller designed in this thesis can effectively suppress the wall vibrations,and thereby the interior noises of the cavity.Finally,a functional prototype of ANC system is set up,and the simulation platform d SPACE is used in the experiments.The noise and vibration signals of the front wall panel are investigated.Experimental results show that the developed ANC system can effectively reduce vibration and noise,which implies a feasibility of the ANC method proposed in this thesis.Based on the piezoelectric effect,this thesis developed a novel ANC method,which might provide an effective way to solve the interior noise problem of vehicles.