A Low-Cost Method of Improving the GNSS/SINS Integrated Navigation System Using Multiple Receivers

Di Liu,Qingyuan Xia,Hengjun Wang,Changhui Jiang

doi:10.3390/electronics9071079

Abstract

GNSS (global navigation satellite system) and SINS (strap-down inertial navigation system) integrated navigation systems have been the apparatus for providing reliable and stable position and velocity information (PV). Commonly, there are two solutions to improve the GNSS/SINS integration navigation system accuracy, i.e., employing GNSS with higher position accuracy in the integration system or utilizing the high-grade inertial measurement unit (IMU) to construct the integration system. However, technologies such as RTK (real-time kinematic) and PPP (precise point positioning) that improve GNSS positioning accuracy have higher costs and they cannot work under high dynamic environments. Also, an IMU with high accuracy will lead to a higher cost and larger volume, therefore, a low-cost method to enhance the GNSS/SINS integration accuracy is of great significance. In this paper, multiple receivers based on the GNSS/SINS integrated navigation system are proposed with the aim of providing more precise PV information. Since the chip-scale receivers are cheap, the deployment of multiple receivers in the GNSS/SINS integration will not significantly increase the cost. In addition, two different filtering methods with central and cascaded structure are employed to process the multiple receivers and SINS integration. In the centralized integration filter method, measurements from multiple receivers are directly processed to estimate the SINS errors state vectors. However, the computation load increases heavily due to the rising dimension of the measurement vector. Therefore, a cascaded integration filter structure is also employed to distribute the processing of the multiple receiver and SINS integration. In the cascaded processing method, each receiver is regarded as an individual “sensor”, and a standard federated Kalman filter (FKF) is implemented to obtain an optimal estimation of the navigation solutions. In this paper, a simulation and a field tests are carried out to assess the influence of the number of receivers on the PV accuracy. A detailed analysis of these position and velocity results is presented and the improvements in the PV accuracy demonstrate the effectiveness of the proposed method.

Highlights

IntroductionHas been widely used to generate position, velocity, and time (PVT) information [1,2]
Represented the global positioning system (GPS), the global positioning navigation system (GNSS)has been widely used to generate position, velocity, and time (PVT) information [1,2]
A simulation and a field tests are carried out to assess the influence of the number of receivers on the position and velocity information (PV) accuracy

Summary

Introduction

Has been widely used to generate position, velocity, and time (PVT) information [1,2]. Signals from the vehicle satellites are broadcast to the earth, and the receivers generate the PVT information by Electronics 2020, 9, 1079; doi:10.3390/electronics9071079 www.mdpi.com/journal/electronics. Due to the long range of the signal transmitting, the signal power is comparatively weak when it reaches the earth [3,4]. The limitation of the signal power leads to the receiver failing to work well under some challenging environments, e.g., in urban canyons, indoors, tunnels, etc. Two major factors obstruct the GNSS positioning accuracy. A momentary partial or total signal blockage attenuates the position accuracy by changing the satellite distribution. While the satellites are totally blocked, the receiver cannot output PVT information [9,10]. In order to construct a seamless navigation system, GNSS is usually integrated with a strap-down inertial navigation system (SINS)

Methods

Results

Discussion

Conclusion