Author Name | Affiliation | Chi Xu | College of Information Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China Advanced Innovation Center for Soft Matter, Beijing University of Chemical Technology, Beijing 100029, China | Yu Jin | College of Information Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China | Hang Liu | College of Information Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China | Duli Yu | Advanced Innovation Center for Soft Matter, Beijing University of Chemical Technology, Beijing 100029, China |
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Abstract: |
It is usually difficult to design a high performance Sigma-Delta (ΣΔ) modulator due to system noises. In this paper, a disturbance observer (DOB) is utilized to estimate the system noises and eliminate their effects on ΣΔ modulators. The applied DOB is introduced with a Bode's ideal cut-off (BICO) filter used for the Q-filter. The proposed DOB with the BICO filter used in ΣΔ modulators can achieve better noise-shaping ability, resulting from the less phase loss of the BICO filter. Finally, the simulation results show that the proposed BICO filter scheme is a useful additional tool for improving the performance of ΣΔ modulators. |
Key words: DOB ΣΔ modulator BICO filter noise-shaping fractional-order system |
DOI:10.11916/j.issn.1005-9113.18066 |
Clc Number:TP212,TN432 |
Fund: |
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Descriptions in Chinese: |
基于Sigma-Delta调制器的带有理想伯德滤波器的干扰观测器设计 徐驰,金予,刘航,俞度立 (1.北京化工大学 信息科学与技术学院 ,北京 100029; 2.北京化工大学 软物质科学与工程高精尖创新中心,北京 100029) 创新点说明:在实际对象的模型建立中,无论采用何种建模方法都不可能得到跟实际对象完全一致的数学模型。因此,模型的实际参数和理想参数存在一定误差,这样的模型不匹配将成为系统分析和设计的不理想因素,同时给设计系统和分析系统带来困难。在MEMS加速度传感器系统中,敏感结构是采用二阶“弹簧-阻尼”机械系统进行模型建立和分析的,由于环境因素(温度,湿度,压力等)会引起敏感结构的二阶模型参数发生变化,造成敏感结构的实际模型和理想模型发生偏差,这样会使得可移动质量块不能完全保持在平衡位置,从而使得整个MEMS加速度传感器系统性能有所下降。再加上,敏感结构不可避免的会受到外界扰动,如果能及时消除这些扰动,可以进一步提高MEMS加速度传感器系统性能。基于以上所述两点,本文将带有理想伯德滤波器的干扰观测器引入到MEMS加速度传感器系统中,实现提高MEMS敏感结构的抗干扰能力,同时实现高鲁棒稳定性目标。带有理想伯德滤波器的干扰观测器在针对系统模型失配、系统存在外部干扰等问题上具有令人满意的解决能力,本文选取理想伯德滤波器作为干扰观测器的低通滤波器,能够提高滤波器阶次的调节范围,同时减小高阶Sigma-Delta调制器系统相位损失,提高系统抗干扰能力。 关键词:干扰观测器 ,ΣΔ调制器,理想伯德滤波器,噪声整形,分数阶系统 |