Differential ultra-wideband indoor positioning method

• US 9,407,317 B2
• Filed: 04/03/2013
• Issued: 08/02/2016
• Est. Priority Date: 04/03/2013
• Status: Expired due to Fees

• Current Assignee: Umm Al-Qura University
• Original Assignee: Umm Al-Qura University
• Inventors: Khalaf-Allah, Mohamed
• Primary Examiner(s): Bythrow, Peter
• Assistant Examiner(s): Seraydaryan, Helena
• Application Number:
  US13/856,419
• Publication Number:
  US 20140301427A1
• Time in Patent Office: 1,217 Days
• Field of Search: 342/465
• US Class Current: 1/1
• CPC Class Codes: G01S 5/021 Calibration, monitoring or correction G01S5/0252 takes precedence
• CPC Class Codes: G01S 5/0218 Multipath in signal reception
• CPC Class Codes: H04B 1/69 Spread spectrum techniques

Abstract

The differential ultra-wideband indoor positioning method provides differential positioning to increase the accuracy of ultra-wideband (UWB) based indoor position estimation. Knowledge about common errors can be learned by employment of a reference source, where the difference between its known and estimated position (differential operation in solution domain), or the difference between the known and measured ranges (differential operation in measurement domain), provides invaluable information to be utilized in reducing errors in estimating the position of the target source. Differential operation accuracy reaches far beyond the accuracy of the non-differential setting.

Claims

1. A computer software product, comprising a non-transitory medium readable by a processor, the non-transitory medium having stored thereon a set of instructions for performing a differential ultra-wideband indoor positioning method, the set of instructions including:

(a) a first sequence of instructions which, when executed by the processor, causes said processor to store in memory a precisely known position of a single reference source (RS) and known positions of n UWB sensors, n≧

3, wherein both a target source (TS) and said single RS are transmitting ultra-wideband (UWB) signals;

(b) a second sequence of instructions which, when executed by the processor, causes said processor to acquire times of arrival (TOA) of both said RS and said TS;

(c) a third sequence of instructions which, when executed by the processor, causes said processor to estimate range and position of said RS and said TS based on said TOA of said ultra-wideband (UWB) signals and known positions of n UWB sensors;

(d) a fourth sequence of instructions which, when executed by the processor, causes said processor to compute the difference between true and estimated range and position parameters of said RS based on said stored precisely known position of said RS, known positions of n UWB sensors, and n TOA measurements;

(e) a fifth sequence of instructions which, when executed by the processor, causes said processor to compute correction factors for said TS estimated range and position based on said computed difference of said RS range and positioning parameters;

(f) a sixth sequence of instructions which, when executed by the processor, causes said processor to recalculate said TS estimated range and position based on said correction factors, wherein sensors involved in the acquisition of said RS and said TS TOA are common to both said TS and said RS;

a seventh sequence of instructions which, when executed-by the processor, causes said processor to calculate η

_i as part of said correction factors computation, said η

_i calculation being characterized by the relation;