基于GMR传感器的小体积二维电子罗盘设计

针对二维电子罗盘存在的体积、精度较难平衡等问题,对二维电子罗盘展开了研究。通过对硬件与算法的优化设计,提出了一种较为实用的解决方案。硬件上采用新型的二维GMR传感器感测磁场,使用C8051F350单片机自带的Δ-ΣA/D模块进行了信号调理,有效减少了信号调理器件,使用了针对GMR传感器优化的算法,在无干扰下可保证其具有较好的辨向精度,在有外部干扰的环境中,通过旋转校准,依然可以保证较高的精度。同时,将校准数据IAP到单片机Flash中,即使系统掉电也可以保证数据不丢失。经国防科技工业弱磁一级计量站的测试,其测试结果表明,该设备在无干扰情况下精度可达±2°,在强干扰下精度依然较高,具有较强的工程实用价值。

Design of miniature electronic compass based on GMR sensor

Aiming at miniaturizing 2-axis electronic compass while maintaining its accuracy, a miniature 2-axis electronic compass based on giant magnetoresistanee （GMR） was investigated and realized by optimizing the hardware and arithmetic. In hardware, the novel GMR was chosen to measure magnetic field, and a △-∑MD converter which is already incorporated into the MCU （C8051F350）was selected to condition the output of GMR sensors. The designed compass is with a compact size, and can be calibrated to eliminate magnetic interference making it suitable for embedded applications. The accuracy of the electronic compass was measured to be±2° without magnetic interference. Even with the presence of magnetic interference, a relatively good accuracy is still achievable if a proper calibration is done. The results indicate that this electronic compass can be applied in many engineering applications.