MEMS数字地震检波器专用DSP芯片优化设计

The new micro-electro-mechanical system (MEMS) digital geophone provides key technological support for the deep oil and gas exploration and development. It has large dynamic range and small disturbance between axises. As it integrates the digital signal processing chip, it can directly output 24-bit digital signal. At recently, the MEMS geophone market is monopolized by foreign countries. As one of the core parts of MEMS geophone, General DSP chip CS5376 was developed by American Cirrus Logic Company more than ten years ago. It has many problems. Such as complicated circuit structure, higher power consumption, high in price, etc. This project intends to research as bellows: 1.optimize timing of chip to control and neglect unconcerned data so as to reduce power; 2.optimize the algorithm design for DSP chip, simplify algorithm as possible in the context of meeting the requirements of performance index, decrease the cost of hardware; this study uses global optimization method (Simulated Annealing、differential evolution) to optimize coefficient of algorithm, decrease the length of coefficient, reduce system power consumption;3. discuss different ways of hardware implements(recursion、non- recursion、polyphase decomposition) to optimize hardware architectures of algorithm; 4.utilize FPGA to prototype test for algorithm;consumption, valuate the power consumption quantitatively after tip-out at last, Expect to reduce power consumption in the performance standards of the premise. If mass-produced,Costs will be reduced about several times. Project has a positive meaning for Localization of exploration equipment.

新一代微机电系统（MEMS）数字地震检波器具有动态范围大、轴间串扰小、防电磁干扰等特点，这为深层油气的勘探开发提供了关键技术支撑。MEMS检波器集成的DSP芯片是其核心部件之一，它能够使检波器直接输出高质量数据。目前MEMS检波器使用的DSP芯片是美国Cirrus Logic公司开发的通用数字信号处理芯片CS5376，存在功耗较高、价格昂贵、并时刻受国外垄断威胁等问题。对此本项目拟开展研究如下：①通过利用时分复用等技术优化设计具有自主知识产权的芯片架构；②针对地震信号的特点，通过全局寻优方法（模拟退火）对芯片核心算法进行优化设计以期在满足地震勘探需要前提下减小硬件开销；③研究算法不同的硬件实现方式进一步降低芯片功耗；④利用FGPA进行原型验证，并最终流片进行实际测试，预期功耗有一定程度降低，若大量生产，成本估计降低数倍。项目对勘探设备的国产化具有一定积极意义。

MEMS数字检波器具有有效响应频带宽、动态范围大、非线性失真度小等显著优势，能够支撑单点高密度采集，进行深层精细油气资源勘探，同时，其优异的矢量保真性能够更好的分离P波和S波，从而可以利用多波信息综合进行裂隙储层油气资源勘探。基于MEMS数字检波器的新一代高精度数字地震采集系统将逐步取代传统的地震采集系统成为重要发展趋势。.作为MEMS检波器核心技术部件之一，抽取滤波芯片是对前端伺服电路ASIC调制所产生的高速低位数据流进行数字滤波处理转换为低速高位数据流，使系统完成高精度的模/数（A/D）转换。课题针对数字抽取滤波芯片主要进行了以下几方面工作：.1）数字抽取滤波芯片的算法设计与优化，包括多级滤波系统参数设计、滤波器系数全局寻优算法优化等。.2）数字滤波专用芯片架构设计和优化，包括芯片时序控制、数据处理、数据输入输出、电源管理等模块的设计与实现。.3）数字滤波专用芯片的集成测试，包括检波器样机架构设计与实现、系统噪声测试、检波器性能参数标定。.研究工作结果表明所设计数字抽取滤波芯片，能够满足其功能要求，其性能指标达到设计要求，集成此芯片的地震检波器与国外同类产品性能相当。