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在实际应用中,光纤光栅传感器的测量精度受到噪声,成本等因素的制约。为了实现低成本的高精度光纤光栅传感器系统,提出了对光纤光栅反射谱采用自适应阈值小波消噪和B多节点样条拟合插值算法的处理技术,并通过实验和仿真得出自适应阈值小波消噪,有效提高了系统的信噪比,在相同采样精度下拟合插值处理前波长检测的误差为0.01nm,处理后误差为0.0017nm,误差降低了一个数量级。实验结果证明该方法不但可以有效降低噪声带来的读取误差,而且提高了测量Bragg波长漂移量的分辨率,从而实现高精度地测量温度、应变等外界参量。 相似文献
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针对超声流量计高精度、低功耗的要求,提出一种自适应采样方法,克服了周期性采样的不足.该方法以相邻二次采样的时差变化率作为动态控制采样周期的主要指标,可根据流体流动情况自动调整采样周期.通过对自适应和周期性采样算法的实验数据进行比较分析,自适应采样方法不仅能在流体波动环境中显著提高计量精度,而且还可以在流体处于稳定时降低系统功耗. 相似文献
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将基于双向梯度的插值点灰度预估和局部纹理强度导向的插值强度自适应控制技术相结合,提出了一种新的自适应图像插值方法.该方法用插值点灰度预估值取代近邻采样值纳人重采样运算,并根据降采样图像的局部空间纹理强度实时调节插值强度,从而在不增大运算开销的前提下,实现了插值重建精度的提升.仿真实验结果说明利用该方法插值重建出的图像具有较高的信噪比PSNR和较低的边缘误差比PEE,且视觉效果更锐利. 相似文献
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设计了一种带自适应斜坡补偿的峰值电流模式(PCM)控制Boost变换器。采用一种低功耗自适应斜坡补偿电路,使得升压(Boost)变换器能够实现宽输出范围和高带载能力。在此基础上,提出了一种应用于Boost变换器的电感电流采样电路,该电路实现了高采样速度和高采样精度,且具备全周期的电感电流采样特点。变换器基于SMIC 180 nm BCD CMOS工艺设计。仿真结果表明,该带自适应斜坡补偿的PCM控制Boost变换器输入电压转换范围为2.8 V~5.5 V,输出电压转换范围为4.96 V~36.1 V,最大输出负载电流高达5 A。 相似文献
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已有的基于Stoer-Bulirsch有理函数插值的自适应频率采样算法往往对插值间隔、收敛精度等参数非常敏感,算法稳定性差,甚至会出现伪收敛等问题.针对已有算法的上述缺陷,通过采用极点判断、插值区域二分、参数变换和多次收敛性检验等措施,提出了一种逐一增加采样点的自适应策略.形成了一种通用性强、稳定性好的自适应频率采样算法,可以用较少的采样点插值重构未知函数响应.并结合多层快速多极子方法,对宽频带目标电磁散射进行计算分析,实现采样频点的自适应选取,减少了计算量极大的精确数值计算的次数,提高了仿真效率. 相似文献
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基亏DSP的多路音/视频采集处理系统设计 总被引:1,自引:0,他引:1
采用TI公司的TMS320DM642型数字媒体数字信号处理器(DSP)设计多路音/视频采集处理系统,实现实时处理4路模拟视频和音频输入、1路模拟/数字视频和1路模拟音频信号输出的功能,该系统可适应PAL/NTSC标准复合视频CVBS或分量视频Y/C格式的模拟信号和标准麦克风或立体声音频模拟输入,具有PAL/NTSC标准S端子或数字RGB模拟/数字信号输出和标准立体声音频模拟输出。并给出软/硬件设计原理和电路。 相似文献
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This paper presents a combined analog/digital demodulation system built around a (PLL) with digital carrier regeneration. The input signal itself is not digitized, but the PLL is digital wherever it is possible. The link between the analog and the digital domain is a 1-bit sigma-delta converter that converts the (quasi-dc) output signal of the PLL's phase detector into a bitstream. The PLL's loop filter doubles as a decimation filter for the bitstream. The analog I and Q output signals are obtained by multiplying the analog input signal with the digital output signal of the PLL in two four-quadrant multiplying digital-to-analog converters 相似文献
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In this work a test strategy for analog circuits based on spectral analysis is proposed. The test strategy is blind, in the sense that only statistical information about the input signal is needed, but no sampling of the input signal is required. This feature allows the test of analog circuits with minimum analog hardware addition. In the context of Systems-on-Chip, this strategy needs only the inclusion of a small random signal generator, and transfers most of the signal processing to the digital domain, allowing the use of a purely digital tester or a digital BIST technique. This paper presents the underlying principle of the method and experimental test results for linear analog systems. 相似文献
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Ohta M. Kohiyama K. Tahara N. Sugihara K. Asami F. Kobayashi O. Hino Y. Akiba T. 《Solid-State Circuits, IEEE Journal of》1990,25(6):1464-1469
A single-chip CMOS LSI that integrates all analog-to-digital (A/D), digital-to-analog (D/A), peripheral, and digital signal processing circuits necessary for a digital National Television System Committee (NTSC) signal decoder is described. The LSI chip accepts composite NTSC video signals in analog form, digitizes them using the on-chip A/D converter, converts them to component RGB signals, and then converts the signals to analog form by using the on-chip D/A converters. The development of circuits that maximize use of the input digital data is discussed. A 6-b A/D circuit is used to reduce the circuit size. Circuits that help maintain acceptable picture quality despite 6-b resolution were developed. Besides analog NTSC signal input and RGB signal output, the IC can also input and output digital NTSC signals, Y/C (luminance, chrominance) signals, and RGB signals. Applications of the LSI are presented 相似文献
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Yan Wang Koichi Hamashita Gábor C. Temes 《Analog Integrated Circuits and Signal Processing》2010,63(2):293-298
A hybrid (analog/digital) architecture is proposed to implement a robust high-resolution delta-sigma modulator with a single-bit
output. The system contains a low-order multi-bit analog noise-shaping loop, followed by a scaling block and a high-order
single-bit digital modulator. The combination simplifies the realization of the analog modulator, and it allows the use of
most of its full-scale input range. 相似文献
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Hsun-Pang Wang Xiaohui Gu Linbo Xie Leang-San Shieh Jason S. H. Tsai Yongpeng Zhang 《Circuits, Systems, and Signal Processing》2012,31(5):1653-1676
This paper presents a digital controller design methodology for multivariable analog systems represented by minimally realizable multiple input–output time-delay transfer function matrices with long time delays. First, the analog transfer function matrix with multiple input–output time delays is minimally realized and represented by a delay-free state-space model and a multiple output-delay function. For a specific multiple time-delay transfer function matrix with complex poles, a minimal realization scheme is newly proposed. Then the minimized delay-free state-space model is utilized for linear quadratic regulator (LQR) design. Furthermore, the designed analog LQR is digitally redesigned via a predictive state-matching method for finding a low-gain digital controller from the pre-designed high-gain analog controller. For implementation of the digitally redesigned controller, a digital observer is constructed for the multiple time-delay system with long time delays. An illustrative example is given to demonstrate the effectiveness of the proposed method. 相似文献
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整个电路采用标准CMOS工艺,采取模块化设计的方法,把数字频率发生器和模拟滤波器部分分开设计。数字频率发生器采用直接数字综合(DDS)的方式,来产生5种不同中心频率(10个通道),简化了传统模拟压控振荡器(VCO)的设计,提高了频率发生器的灵活性;根据精度要求,模拟高斯低通滤波器采用5阶低通滤波器来进行逼近。并论述和讨论了一种用数字和模拟混合集成电路来实现一维模拟输入的连续小波变换(CWT)芯片的方法。 相似文献
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A Rank Encoder: Adaptive Analog to Digital Conversion Exploiting Time Domain Spike Signal Processing
Philipp Häfliger Elin Jørgensen Aasebø 《Analog Integrated Circuits and Signal Processing》2004,40(1):39-51
An electronic circuit is presented that encodes an array of analog input signals into a digital number. The digital output is a rank order code that reflects the relative strength of the inputs, but is independent of the absolute input intensities. In that sense, the circuit performs an adaptive analog to digital conversion, adapting to the average intensity of the inputs (i.e. effectively normalizing) and adapting the quantization levels to the spread of the inputs. Thus, it can convey essential information with a minimal amount of output bits over a huge range of input signals.As a first processing step the analog inputs are projected into the time domain, i.e. into voltage spikes. The latency of those spikes encodes the strength of the input. This conversion enables the circuit to conduct further analog processing steps by asynchronous logic. 相似文献
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《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》1972,60(8):1007-1008
The accuracy with which the mean of an analog signal can be estimated from the mean after quantization by an analog/digital converter is examined. The mean of the quantized signal is a good measure of the mean of the input, down to lower values of input noise than is commonly supposed. 相似文献
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TLC0834是TI公司生产的八位逐次逼近模数转换器 ,具有输入可配置的多通道多路器和串行输入方式。文中以AT89C51CPU为核心 ,采用LTC0834八位串行A/D转换器设计了一个可将模拟信号转换为数字信号的电路 相似文献