Study On Active Vibration Control Of Gear Transmission System Based On Nonlinear Adaptive Filtering Algorithm

In the mechanical systems, gear is one of the most widely used driving ways, so the vibration control of gear system is the focus of the current research. Especially in recent years, the requirement of these fields, such as aeronautic, aerospace and robot, demands more on the accuracy, vibration, noise and reliability in the gear driving system. In practical application of the gear transmission system, the manufacture and installation errors and the teeth deformation caused by the load are unavoidable. It introduces the nonlinear factors in the work process of gear system, then the internal incentive engendered by collision and impact between the teeth causes the nonlinear vibration.In this paper, in order to control the vibration of gear transmission system, an active control structure in the internal gearbox is developed, which is based on the active shaft transverse vibration control concept. This approach makes the control force directly work on the shaft near the excitation source, so that the vibration response of two pairs gears is controlled which is caused by the mesh errors synchronously. Two piezoelectric stack actuators are constructed with the piezoelectric smart material. Based on nonlinear adaptive filtering algorithm, the force generated by the actuator can attenuate bending vibration of the shaft, so as to achieve the aim of attenuation vibration of gear transmission system. The main contributions of the dissertation include the following:â‘  In order to analyze the nonlinear dynamic response of gear system, a 12 degree of freedom vibration mathematical model of the two stage spur gear system is established by using the lumped mass method, in which the nonlinear clearance and time-varying mesh stiffness is concerned. Based on the model, the Newmark iteration algorithm is adopted to solve the differential equations. Then the nonlinear dynamic response caused by the contact loss is analyzed, and a foundation for active vibration control of gear system is laid.â‘¡ According to active shaft transverse control concept, an active vibration control structure of gear system with actuator radial layout is adopted. Based on the nonlinear characteristics of gear transmission system, a vibration active control scheme based on the nonlinear adaptive filtering algorithm improved through Fx LMS is adopted. This paper expounds the basic principle of nonlinear adaptive filtering algorithm and construct the linear and nonlinear primary path model and the minimum phase and non-minimum phase of the secondary path model, the simulation analysis the controlperformance of the nonlinear adaptive filtering algorithm and Fx LMS algorithm.â‘¢ The performance characteristics of online secondary path identification technology-adding noise technology and direct estimation error technology is analyzed,the active vibration control simulation verification is carried out.â‘£ An active vibration control experiment platform is constructed and the active control test is carried out. The active controller with double input/double output based on the nonlinear adaptive filtering algorithm is designed, the direct estimation error technology is adopted to online secondary path modeling, the experiment study on the active vibration control of two stage gear transmission system is carried out. It verifies the feasibility and effectiveness of the controller and the control structure, and the superiority of the nonlinear adaptive filtering algorithm applied in active vibration control of gear transmission system.