A Novel Ultra-Wideband Double Difference Indoor Positioning Method with Additional Baseline Constraint

Abstract

Ultra-wideband (UWB) technology is suitable for indoor positioning owing to its high resolution and penetration. However, the current UWB positioning methods not only fail to fully analyze errors, but do not have the ability to eliminate gross and large random errors. In this article, the errors of UWB indoor positioning are analyzed comprehensively, and the basic function model is given. An indoor positioning method based on a double difference UWB with ranging observations is proposed and realized. In the proposed method, two UWB rover stations and a common base station are introduced, and the known baseline length between two rovers is used as the constraint condition for quality control. The observations and coordinate estimations are constrained by the prior and posteriori, respectively, and the weight of ranging observations with large residuals is reduced. Two groups of static experiments are designed. After adopting the proposed method, the plane error of one rover is 3.4 cm and 2.1 cm, and plane error of another rover is 3.3 cm and 2.0 cm, respectively. The positioning precision is improved by more than 80% compared with the traditional method. In the dynamic experiment, the coordinates of the starting and ending point obtained by the proposed method are basically consistent with the truth value, and the positioning results are close to the reference trajectory. The experimental results show that the proposed method can eliminate systematic and large random errors and improve the positioning precision effectively.

Posture algorithm for mobile robot based on ultrawide band

“…27,28 At present, the positioning accuracy has been improved by the researchers, and the simulation error of 2 cm is chosen as the lower limit in this article. 29 We suppose the coordinates of the three base stations are (0,0), (0, 800), and (800, 0); the robot centroid coordinates (400, 400); target point position (800, 800); actual posture angle 45°; and the installation distance of the two tags 60 cm. The posture angle of the robot θ I in the plane coordinate system is simulated with the positioning errors of 8, 6, 4, and 2 cm (Figure 6).…”

System and Method for Reducing NLOS Errors in UWB Indoor Positioning

“…Indoor Positioning Systems (IPSs) are crucial in diverse fields, from emergency services to industrial automation [1]. The most used satellite technologies, like the Global Navigation Satellite System (GNSS) [2], are ineffective indoors due to signal attenuation caused by building materials and environmental factors [3].…”

“…Ultra-wideband (UWB) technology has been increasingly recognized as an efficacious strategy for IPSs due to its high accuracy, low transmission cost, and robustness to environmental perturbations [4]. The Federal Communication Commission (FCC) defines the UWB signal by one of the two conditions: (1) The signal bandwidth should be wider than 0.2 times the carrier frequency, or (2) the signal bandwidth should be wider than 500 MHz. The fine time resolution and broad bandwidth of UWB technology enable precise location tracking, making it superior to other IPSs like WiFi or Bluetooth [5], especially in complex indoor scenarios.…”

Comprehensive Evaluations of NLOS and Linearization Errors on UWB Positioning

“…Additionally, UWB has a strong penetration ability under the situations such as in woods and stones, and these penetration errors can be corrected by modeling. However, UWB has a weak ability to penetrate water and metal [16]. Currently, UWB modes include Time of Arrival (TOA), Time of Flight (TOF), Difference of Time-Of-Arrival (TDOA), Angle of Arrival (AOA), Received Signal Strength Indication (RSSI) [17,18].…”