Location Filtering via Device Mobility Classification

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Solution Overview

Problem

The time-varying nature of RF signals leads to inaccuracies in tracking the location of both stationary and mobile devices, despite the use of filtering techniques, resulting in significant errors in determining the actual path of mobile devices.

Innovation Solution

A method that classifies devices as stationary or mobile based on location information, adjusting filter parameters such as measurement noise and process noise covariance for Kalman filters to improve location estimation accuracy, by determining whether a device is likely to be stationary or mobile, thereby selecting appropriate filter settings to enhance tracking precision.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If filtering is applied to location data to reduce measurement noise, then location estimation accuracy improves for stationary devices, but tracking precision deteriorates for mobile devices due to time-varying RF signal characteristics

Engineering Contradiction:
Improvelocation estimation accuracyVSAvoidtracking precision
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The system dynamically adjusts filter parameters based on device mobility detection. When a device is detected as mobile, the system switches from using stationary device filters to mobile device filters, allowing the filtering characteristics to adapt to the time-varying nature of RF signals from moving devices. This dynamic adaptation resolves the contradiction by enabling optimal filtering for each device state rather than using a fixed filtering approach.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes filter parameters (such as measurement noise covariance and process noise covariance) based on the detected mobility state of the device. By adjusting these parameters according to whether the device is stationary or mobile, the system optimizes location estimation accuracy for each state, thereby resolving the contradiction between filtering effectiveness for stationary devices and tracking precision for mobile devices.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If a single filter configuration is used for all devices, then system complexity is reduced, but location tracking accuracy deteriorates due to inability to adapt to different mobility states

Engineering Contradiction:
Improvesystem complexityVSAvoidlocation tracking accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The system segments the device population into stationary and mobile categories based on mobility detection. By dividing devices into these distinct groups, the system can apply different filter configurations to each segment, improving location tracking accuracy for both stationary and mobile devices while maintaining manageable system complexity through clear classification categories.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically selects appropriate filter configurations based on real-time mobility detection. Rather than maintaining multiple static filter configurations simultaneously, the system uses mobility detection to dynamically switch between filter types, reducing system complexity while adapting to different device states to maintain high location tracking accuracy.

Inventive Principle:
Principle #15Dynamics

3Measurement precision

If filtering parameters are optimized for stationary devices, then location estimation accuracy improves, but tracking errors increase for mobile devices due to inappropriate filter settings

Engineering Contradiction:
Improvelocation estimation accuracyVSAvoidtracking error
Core Design Contradiction:
Measurement precisionVSManufacturing precision

Solution Approach 1:

The system changes filter parameters (measurement noise covariance, process noise covariance) based on the detected mobility state. For mobile devices, the system adjusts these parameters to account for the time-varying nature of RF signals, thereby reducing tracking errors. This parameter adaptation allows the system to maintain high location estimation accuracy across both stationary and mobile devices without the tracking errors that would result from using stationary-optimized filters for mobile devices.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS8248233B2Location filtering based on device mobility classification
Publication Date: 2012.08.21 CISCO TECHNOLOGY INC
  • US8248233B2 patent drawing
  • US8248233B2 patent drawing
  • US8248233B2 patent drawing

AI summary

In one embodiment, a method includes obtaining location information associated with a remote device, and processing the location information. Processing the location information includes determining if the remote device is mobile. The method also includes configuring a filter such that at least one parameter indicates that the remote device is mobile if the remote device is mobile, and configuring the filter such that the at least one parameter indicates that the remote device is approximately stationary if the remote device is not mobile. The filter is applied to the location information to generate a filtered location estimate which is arranged to estimate a location of the remote device.