牙嵌式自由轮差速器消声环的设计与强度分析

消声环是牙嵌式自由轮差速器降噪减震的重要零部件。在差速器的工作过程中,主动环与从动环频繁的接合、分离容易导致消声环齿的断裂。消声环齿的强度是牙嵌式自由轮差速器设计过程中需要重点考虑的因素。本文根据牙嵌式自由轮差速器的结构与工作原理,对牙嵌式自由轮差速器消声环进行设计。通过Solidworks进行建模,并用Ansys Workbench进行仿真分析,对不同齿形及齿数的消声环强度进行计算,选择出合理的消声环齿形和齿数。

Automatic Stabilization of an Adaptive Feedback Control for Noise Cancelling In-ear Headphones

Headphones with an integrated active noise cancellation system have been increasingly introduced to the consumer market in recent years. When exposing the human ear to active noise sources in this striking distance, the ensuring of a safe sound pressure level is vital. In feedback systems, this is coupled with the stability of the closed control loop; stable controller design is thus essential. However, changes in the control path during run-time can cause the stable control system to become unstable, resulting in an overdrive of the speakers in the headphones. This paper proposes a method, which enables the real-time analysis of the current system state and if necessary stabilizes the closed loop while maintaining the active noise reduction. This is achieved by estimating and evaluating the open loop behavior with an adaptive filter and subsequently limiting the controller gain in respect to the stability margin.