Technion-Israel Institute of Technology, Haifa 32000, Israel.
Sensors (Basel). 2019 Mar 7;19(5):1170. doi: 10.3390/s19051170.
One of the common ways for solving indoor navigation is known as Pedestrian Dead Reckoning (PDR), which employs inertial and magnetic sensors typically embedded in a smartphone carried by a user. Estimation of the pedestrian's heading is a crucial step in PDR algorithms, since it is a dominant factor in the positioning accuracy. In this paper, rather than assuming the device to be fixed in a certain orientation on the pedestrian, we focus on estimating the vertical direction in the sensor frame of an unconstrained smartphone. To that end, we establish a framework for gravity direction estimation and highlight the important role it has for solving the heading in the horizontal plane. Furthermore, we provide detailed derivation of several approaches for calculating the heading angle, based on either the gyroscope or the magnetic sensor, all of which employ the estimated vertical direction. These various methods-both for gravity direction and for heading estimation-are demonstrated, analyzed and compared using data recorded from field experiments with commercial smartphones.
解决室内导航的常用方法之一是行人航位推算 (PDR)，它使用通常嵌入在用户携带的智能手机中的惯性和磁传感器。在 PDR 算法中，估计行人的航向是一个关键步骤，因为它是定位精度的主要因素。在本文中，我们不是假设设备在行人身上固定在某个方向，而是专注于估计不受约束的智能手机传感器框架中的垂直方向。为此，我们建立了一个重力方向估计框架，并强调了它在解决水平面上的航向问题方面的重要作用。此外，我们详细推导出了几种基于陀螺仪或磁传感器计算航向角的方法，所有这些方法都使用估计的垂直方向。使用从商业智能手机的现场实验中记录的数据，演示、分析和比较了这些用于重力方向和航向估计的各种方法。
