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, t...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.展开更多
This paper describes a full waveform sampling LiDAR system applying stripe principle. A kind of denoising method based on edge detection of original stripe signal is proposed. This method is compared with other denois...This paper describes a full waveform sampling LiDAR system applying stripe principle. A kind of denoising method based on edge detection of original stripe signal is proposed. This method is compared with other denoising methods, such as Wiener filtering, mean filtering and median filtering. It is found that the proposed denoising method is much more effective for dealing with the waveform signals.展开更多
文摘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.
基金supported by the National Natural Science Foundation of China(No.11004042)the National Key Scientific Instrument and Equipment Development Projects(No.2012YQ040164)the Science Funds of Heilongjiang Province(No.F2016015)
文摘This paper describes a full waveform sampling LiDAR system applying stripe principle. A kind of denoising method based on edge detection of original stripe signal is proposed. This method is compared with other denoising methods, such as Wiener filtering, mean filtering and median filtering. It is found that the proposed denoising method is much more effective for dealing with the waveform signals.
