新型Σ-Δ多通道动态测试分析系统研究与实现

 动态测试与分析系统需要动态范围（DRN）大、信噪比（SNR）高，传统方法实现复杂且成本高。本文分析了Σ-Δ调制的动态特性，提出基于Σ-Δ ADC(模-数转换器)ADS1271，Σ-Δ DAC（数-模转换器）AIC23及浮点数字信号处理器（DSP）芯片TMS320C6713的新型高精度动态测试与分析系统，实现了多通道实时动态测试与分析，系统具有24位采集精度，8通道可级联基本模块，实时频率细化FFT（Zoom-FFT）、功率谱密度（PSD）等分析功能, 正弦、瞬态扫频、随机和冲击响应谱等信号源功能以及高速USB2.0数据传输功能。系统用于振动、冲击、噪声工程等测试与分析系统，可取代国外最新产品。

Research and Development of Multi-channel Dynamical Test and Analysis System Based on Sigma-Delta Model

This article presents an introduction to a new dynamical testing and analytical system. It begins with a discussion of over sampling techniques and the theory and advantages of Σ-Δ devices for digital-to-analogue conversion(DAC), which is very suitable for dynamical testing systems. Based on Σ-Δ ADC (analogue-to-digital- converter) ADS1271, Σ-Δ DAC AIC23 and digital signal processor (DSP) TMS320C6713, the article then proposes a system with high performance of 24 bits in each of the 8 channels and many functions of digital signal processing, signal sources producing and data transmitting. The digital signal processing involves fast Fourier transform (FFT), Zoom FFT, power spectral density (PSD) and other functions. The signal sources can produce sine wave, swept wave, random wave and shock response spectrum. All the data can be transmitted to/from PC application.The system is designed for data display, secondary signal processing, signal source controlling and the interface between the users and PC, via USB2.0 devices. It can be used in vibration, shock and noise testing and control projects to replace imported hitech products.