惯性导航系统中浮点计算加速单元设计

Design of floating point calculation acceleration unit in inertial navigation system

石英振梁加速度计采用频率输出的形式表示加速度,在惯性导航系统中,需要将频率值转换为加速度值,再进行姿态解算。采用软件方法进行浮点计算,需要耗费CPU大量的计算能力。为了优化频率转换的计算速度,设计一种面向频率转换应用的浮点计算加速单元,并基于FPGA进行了实现与验证。结果表明,系统从数据采样到频率转换,然后将频率值转换成加速度进行姿态解算,陀螺仪测得的角速度进行积分,最后完成数据融合,使用本文设计的浮点加速单元来实现频率转换,速度提高了2倍。

Quartz vibrating beam accelerometer expresses acceleration in the form of frequency output. In the inertial navigation system, it is necessary to convert the frequency value into an acceleration value and then perform attitude calculation. Using software method for floating point calculation requires a lot of computing power of CPU. In order to optimize the calculation speed of frequency conversion, the paper designs a floating-point calculation acceleration unit for frequency conversion applications, which is implemented and verified based on FPGA. The results show that the system from data sampling to frequency conversion, then converts the frequency value into acceleration for the attitude calculation. The angular velocity measured by the gyroscope is integrated, and finally the data fusion is completed. Using the floating-point acceleration unit designed in the paper to achieve frequency conversion, the speed is improved by 2 times.