Precise and Robust RTK-GNSS Positioning in Urban Environments with Dual-Antenna Configuration

Abstract

Robust and centimeter-level Real-time Kinematic (RTK)-based Global Navigation Satellite System (GNSS) positioning is of paramount importance for emerging GNSS applications, such as drones and automobile systems. However, the performance of conventional single-rover RTK degrades greatly in urban environments due to signal blockage and strong multipath. The increasing use of multiple-antenna/rover configurations for attitude determination in the above precise positioning applications, just as well, allows more information involved to improve RTK positioning performance in urban areas. This paper proposes a dual-antenna constraint RTK algorithm, which combines GNSS measurements of both antennas by making use of the geometric constraint between them. By doing this, the reception diversity between two antennas can be taken advantage of to improve the availability and geometric distribution of GNSS satellites, and what is more, the redundant measurements from a second antenna help to weaken the multipath effect on the first antenna. Particularly, an Ambiguity Dilution of Precision (ADOP)-based analysis is carried out to explore the intrinsic model strength for ambiguity resolution (AR) with different kinds of constraints. Based on the results, a Dual-Antenna with baseline VEctor Constraint algorithm (RTK) is developed. The primary advantages of the reported method include: 1) Improved availability and success rate of RTK, even if neither of the two single-antenna receivers can successfully solve the AR problem; and 2) reduced computational burden by adopting the concept of measurement projection. Simulated and real data experiments are performed to demonstrate robustness and precision of the algorithm in GNSS-challenged environments.

Online Tuning of PID Controller Using a Multilayer Fuzzy Neural Network Design for Quadcopter Attitude Tracking Control

“…In past decades, many studies have been conducted to solve such problems (time-consuming, costly, etc. ; Fatan et al, 2013 ; Kuantama et al, 2017 ; Noordin et al, 2017 ; Rouhani et al, 2017 ; Sumardi and Riyadi, 2017 ; Prayitno et al, 2018 ; Thanh and Hong, 2018 ; Chen et al, 2019 ; Rabah et al, 2019 ; Soriano et al, 2020 ). The Ziegler Nichols method is a well-known for tuning PID parameters (Azman et al, 2017 ).…”

Attitude Determination and RTK Performances Amelioration Using Multiple Low-Cost Receivers with Known Geometry

“…Khodabandeh et al [7] introduced a concept of array-based between-satellite single difference satellite phase biases determination to accelerate the single-receiver IAR, but they did not take into consideration the attitude information of the vehicle which cannot analyze the influence with attitude consideration. Peirong Fan et al [8] proposed a dual-antenna constraint RTK algorithm to improve the system AR success rate, which combines GNSS measurements of both antennas by making use of the baseline vector constraint between them. However, the attitude information of the vehicle is still not taken into account.…”

High-Accuracy Position-Aware Robot for Agricultural Automation Using Low-Cost IMU-Coupled Triple-Laser-Guided (TLG) System

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