RTK/Pseudolite/LAHDE/IMU-PDR Integrated Pedestrian Navigation System for Urban and Indoor Environments.

Ruihui Zhu,Baoguo Yu,Hongji Cao,Yunjia Wang,Lu Huang,Haonan Jia,Heng Zhang,Jianqiang Chen,Xingli Gan,Shuang Li

doi:10.3390/s20061791

Abstract

This paper presents an evaluation of real-time kinematic (RTK)/Pseudolite/landmarks assistance heuristic drift elimination (LAHDE)/inertial measurement unit-based personal dead reckoning systems (IMU-PDR) integrated pedestrian navigation system for urban and indoor environments. Real-time kinematic (RTK) technique is widely used for high-precision positioning and can provide periodic correction to inertial measurement unit (IMU)-based personal dead reckoning systems (PDR) outdoors. However, indoors, where global positioning system (GPS) signals are not available, RTK fails to achieve high-precision positioning. Pseudolite can provide satellite-like navigation signals for user receivers to achieve positioning in indoor environments. However, there are some problems in pseudolite positioning field, such as complex multipath effect in indoor environments and integer ambiguity of carrier phase. In order to avoid the limitation of these factors, a local search method based on carrier phase difference with the assistance of IMU-PDR is proposed in this paper, which can achieve higher positioning accuracy. Besides, heuristic drift elimination algorithm with the assistance of manmade landmarks (LAHDE) is introduced to eliminate the accumulated error in headings derived by IMU-PDR in indoor corridors. An algorithm verification system was developed to carry out real experiments in a cooperation scene. Results show that, although the proposed pedestrian navigation system has to use human behavior to switch the positioning algorithm according to different scenarios, it is still effective in controlling the IMU-PDR drift error in multiscenarios including outdoor, indoor corridor, and indoor room for different people.

Highlights

The pedestrian navigation technologies can be divided into relative positioning and absolute positioning
Sensors 2020, 20, 1791 which made the fact that when the pedestrian’s foot is in contact with the ground, the actual velocity of the foot is zero, and when the still phase is detected, the velocity derived by inertial navigation system (INS) is used as the measured error and fed to extended Kalman filter (EKF) to estimate the velocity error, called as INS-EKF-zero velocity detection update (ZUPT) (IEZ)
1 in for assisting the Real-time kinematic (RTK) to improve the system robustness and positioning accuracy is shown in O

Summary

Introduction

The pedestrian navigation technologies can be divided into relative positioning and absolute positioning. The inertial navigation system (INS) is commonly used for relative positioning which uses the acceleration and angular rate output by inertial measurement unit (IMU) to integrate to obtain velocity and attitude. The acceleration and angular rate information both include random noises, which result in integral cumulated errors in velocity and heading [1]. A zero velocity detection update (ZUPT) technique was proposed to aid the inertial navigation system (INS) [2,3,4], Sensors 2020, 20, 1791; doi:10.3390/s20061791 www.mdpi.com/journal/sensors. The IEZ algorithm is unable to estimate the error in heading because it cannot obtain the heading observations. A zero angular rate update algorithm (ZARU) was proposed to eliminate the error in heading [5], which is not constrained by the external environment, it had limited ability to correct heading. Heuristic drift elimination (HDE) algorithm [6]

Methods

Results

Conclusion