惯性测量组合24位数据采集模块的设计

针对中高精度惯性测量组合中,陀螺和加速度计输出信号动态范围大,精度高,随机漂移小,非线性度小的特点,设计了一种采用24位Σ-Δ型模数转换器的惯性测量组合六通道并行数据采集模块,它由差分放大器、ADS1278、现场可编程门阵列(FPGA)及微控制器(MCU)构成.介绍了该模块的的设计方案,同时结合高精度模数转换器的特点,分析了信号驱动、基准源、时钟、电源及模数转换器等产生的误差,提出了充分发挥高精度模数转换器性能的优化设计方法.实际使用表明,该采集模块满足系统高精度、高可靠性要求.

Design of 24-Bit Data Acquisition Module of IMU

Since the IMU with middle and high precision has characterized by wide dynamic range of output signal, high precision, small random drift and nonlinearity, a data acquisition module based on 24-bit delta-sigma analog-to-digital converter is designed, which allows simultaneously sampling of six channels. Firstly, this paper introduces the design scheme of the module, which consists of fully-differential amplifier, analog-to-digital converter, FPGA and microcontroller. Secondly, considering the characteristics of high-precision analog-to-digital converter, an analysis is made on the data acquisition error caused by signal regulation, voltage reference, clock, power supply and analog-to-digital converter. A method is presented to improve the performance of data acquisition module. The application results show that the module can satisfy the high-precision and high-reliability requirements of IMU.