Radio Signal Phase Change Detection for Position Drift Correction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing navigation and measurement systems require significant effort and resources to determine position changes and often struggle with accuracy, especially in complex environments where multi-pathing effects hinder distance determinations.

Innovation Solution

A process that evaluates phase changes in radio signals to detect relative movement or the absence of movement by comparing phase measurements at different times, using multiple radio signals from various directions to minimize ambiguities and account for environmental changes, allowing for precise detection of resting states with simple hardware and existing signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple measurements with different frequencies are used to determine position, then measurement accuracy is improved, but system complexity and resource requirements increase

Engineering Contradiction:
Improveposition determination accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts only the phase information from radio signals rather than performing full signal processing with multiple frequencies. By focusing solely on phase measurements at a single frequency, the system achieves position determination without the complexity of multi-frequency analysis, eliminating unnecessary computational and hardware resources while maintaining measurement capability

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes the measurement parameter from multi-frequency signal analysis to single-frequency phase difference measurement. This parameter transformation simplifies the measurement process by using only the phase component of the signal, avoiding the need for complex multi-frequency processing while still enabling accurate position determination through phase comparison

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If phase change evaluation is used to detect relative movement, then movement detection sensitivity is improved, but ambiguities due to equi-phase lines increase

Engineering Contradiction:
Improvemovement detection sensitivityVSAvoidmeasurement ambiguity
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent resolves phase ambiguities by introducing a temporal dimension - comparing phase measurements taken at different times (t1 and t2). This time-based approach transforms the problem from a two-dimensional phase space with equi-phase line ambiguities into a three-dimensional measurement space where the phase difference over time uniquely identifies displacement, eliminating the ambiguity problem

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The system performs a preliminary phase measurement at time t1, then uses this initial measurement as a reference for subsequent measurements at time t2. This preliminary action establishes a baseline that allows the system to detect and correct for environmental phase changes, thereby resolving ambiguities in the second measurement through comparison with the known initial state

Inventive Principle:
Principle #10Preliminary action

3Speed

If inertial sensors are used to detect movements and calculate speed, then speed determination is possible, but drift errors accumulate over time

Engineering Contradiction:
Improvespeed determination capabilityVSAvoiddrift error
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The patent implements feedback by using radio signal phase measurements to monitor and correct inertial sensor drift. The system continuously compares the position information derived from inertial integration with the position information from radio signal phase differences, and uses this feedback to correct accumulated drift errors in the inertial measurements, maintaining long-term accuracy

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The invention merges two different measurement approaches - inertial sensing and radio signal phase measurement - into a unified positioning system. By combining the high-rate motion detection capability of inertial sensors with the drift-free absolute position reference from radio phase measurements, the system achieves both accurate speed determination and long-term reliability without drift accumulation

Inventive Principle:
Principle #5Merging (Combining)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach enables highly sensitive movement detection with high accuracy, such as 3 mm at 2.4 GHz frequency, and simplifies the process while using existing signals, even in complex environments, and can improve inertial sensor measurements by correcting drift.

Implementation Method 1

The present process is based on an evaluation of changes of the phase of a radio system in order to determine on its basis either a relative movement, or respectively to detect precisely the absence of such relative movement, the resting that is

Methodology Applied
Scientific EffectPhase change of radio signal: Doppler Effect

Data Source

PatentEP2786170B1Process for the determination of a position change or respectively resting and/or speed of an object
Publication Date: 2020.05.06 LAMBDA 4 ENTWICKLUNGEN GMBH
  • EP2786170B1 patent drawingFigure 1
  • EP2786170B1 patent drawingFigure 2

AI summary

The present invention relates to a process for determining a position change or respectively the resting and/or a speed of an object, respectively a corresponding process for supporting an inertial measurement system. Many processes for the determination of a position are known. Thus for example satellite based processes are known which can determine a position by evaluating radio signals. This is how also on the basis of several measurements and corresponding differences, position changes, or respectively, when taking into account the time periods elapsed between the measurements, speeds can be determined. It is an object of the present invention, however, to provide an alternative system which can provide reliable results with less effort and which particularly makes a direct detection of a location change possible. This problem is solved by providing a process, in which respectively at least one radio signal (FS) is received on the object (O) at at least one first and one second point in time, particularly continuously, and the change of the phase of said radio signal is determined for a determination of a relative movement between source (U) of said signal or a reference location and said object (O), and the relative movement between source (U) of said signal or the reference location and said object (O) is detected.