Inertial sensing suites now permeate all forms of smart automation, yet a plateau exists in the real-world derivation of global orientation. Magnetic field fluctuations and inefficient sensor fusion still inhibit deployment. In this article, we introduce a new algorithm, an extended complementary filter (ECF), to derive 3-D rigid body orientation from inertial sensing suites addressing these challenges. The ECF combines computational efficiency of classic complementary filters with improved accuracy compared to popular optimization filters. We present a complete formulation of the algorithm, including an extension to address the challenge of orientation accuracy in the presence of fluctuating magnetic fields. Performance is tested under a variety of conditions and benchmarked against the commonly used gradient decent inertial sensor fusion algorithm. Results demonstrate improved efficiency, with the ECF achieving convergence 30% faster than standard alternatives. We further demonstrate an improved robustness to sources of magnetic interference in pitch and roll and to fast changes of orientation in the yaw direction. The ECF has been implemented at the core of a wearable rehabilitation system tracking movement of stroke patients for home telehealth. The ECF and accompanying magnetic disturbance rejection algorithm enables previously unachievable real-time patient movement feedback in the form of a full virtual human (avatar), even in the presence of magnetic disturbance. Algorithm efficiency and accuracy have also spawned an entire commercial product line released by the company x-io. We believe the ECF and accompanying magnetic disturbance routines are key enablers for future widespread use of wearable systems with the capacity for global orientation tracking.

中文翻译：

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用于全身MARG方向估计的扩展互补滤波器

惯性传感套件现在已经渗透到所有形式的智能自动化中，但是在全球定位的现实世界中仍然存在高原。磁场波动和传感器融合效率低下仍然阻碍部署。在本文中，我们介绍了一种新算法，即扩展互补滤波器（ECF），可从惯性传感套件中获得3-D刚体定向，以解决这些挑战。与流行的优化滤波器相比，ECF将经典互补滤波器的计算效率与更高的精度相结合。我们提出了算法的完整表述，包括扩展以解决存在波动磁场时定位精度的挑战。性能在各种条件下进行测试，并以常用的梯度体面惯性传感器融合算法为基准。结果表明效率得到了提高，ECF的收敛速度比标准替代品快30％。我们进一步证明了对俯仰和横滚中的电磁干扰源以及在偏航方向上快速改变方向的鲁棒性。ECF已在可穿戴康复系统的核心中实施，该系统可跟踪中风患者的运动以进行家庭远程医疗。ECF和随附的电磁干扰抑制算法即使在存在电磁干扰的情况下，也可以以完整的虚拟人（化身）的形式实现以前无法实现的实时患者运动反馈。算法的效率和准确性也催生了x-io公司发布的整个商业产品线。我们认为，ECF及其附带的电磁干扰程序是可穿戴系统未来广泛使用的主要推动力，这些系统具有全球定位跟踪能力。