In this paper, we analyze the relationship between sensor bandwidth and heading drift, and improve a pedestrian dead-reckoning (PDR) system considering the heading drift by the insufficient bandwidth. The PDR system using foot-mounted inertial measurement unit (IMU) is generally based on an inertial navigation system (INS). In order to reduce the estimated position error, INS is combined with the zero-velocity update (ZUPT), which assumes that the pedestrian shoe velocity is zero at the stance phase. Although the error can be reduced through ZUPT, the estimation errors due to other causes remain. The angular rate and acceleration signals measured from the inertial sensor have various frequency components depending on the motion of the shoe. In the heel strike phase, the signals change sharply due to the impact, and the high frequency components are generated compared to the other phase. Considering only the accuracy of the inertial sensor and using a sensor with insufficient bandwidth, estimation errors occur in the PDR system. In the standard PDR system, loss of information due to narrow bandwidth causes heading drift, which is the unobservable state in the filter. In order to compensate for the heading drift due to the insufficient bandwidth, we analyze the estimation errors according to the bandwidth. Moreover, we propose a PDR system considering the heading drift estimated based on sensor bandwidth. To improve the estimation performance of the PDR system, the proposed system compensates the heading drift according to the sensor bandwidth in the heel strike with the high frequency components. The experimental results show that the improved performance of the proposed system compared with the standard algorithm.

在本文中，我们分析了传感器带宽与航向漂移之间的关系，并通过带宽不足改进了考虑航向漂移的行人航位推算（PDR）系统。使用脚踏式惯性测量单元 (IMU) 的 PDR 系统通常基于惯性导航系统 (INS)。为了减少估计的位置误差，INS 与零速度更新 (ZUPT) 相结合，它假设行人鞋速度在站立阶段为零。虽然通过 ZUPT 可以减少误差，但由于其他原因导致的估计误差仍然存在。从惯性传感器测得的角速率和加速度信号根据鞋子的运动具有不同的频率分量。在足跟撞击阶段，信号因撞击而急剧变化，并且与其他相位相比产生高频分量。仅考虑惯性传感器的精度，使用带宽不足的传感器，在PDR系统中会出现估计误差。在标准 PDR 系统中，由于带宽窄导致信息丢失导致航向漂移，这是滤波器中不可观察的状态。为了补偿由于带宽不足导致的航向漂移，我们根据带宽来分析估计误差。此外，我们提出了一种考虑基于传感器带宽估计的航向漂移的 PDR 系统。为了提高 PDR 系统的估计性能，所提出的系统根据具有高频分量的足跟撞击中的传感器带宽来补偿航向漂移。