Dead Zone Mitigation for Vehicle Passive Entry Systems

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Solution Overview

Problem

Passive entry passive start (PEPS) systems face dead zones around vehicles where antenna modules cannot accurately measure signal strength from mobile devices, leading to unreliable location tracking and impaired functionality.

Innovation Solution

The implementation of antenna modules that generate predictors based on past signal strength measurements and algorithms like Kalman filters and Markov Chains to estimate the location of mobile devices within dead zones, enabling passive entry when multiple predictors match and a user is detected, and unlocking doors accordingly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If antenna modules are used to measure signal strength from mobile devices, then passive entry functionality is enabled, but dead zones are created where signal strength cannot be accurately measured

Engineering Contradiction:
Improvepassive entry functionalityVSAvoidsignal strength measurement reliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent introduces predictor modules as intermediary components that generate predicted signal strength values when direct measurement is unavailable. These predictors act as mediators between the antenna modules and the passive entry system, providing estimated signal strength data that allows the system to function in dead zones while maintaining measurement reliability through multiple prediction methods (e.g., based on historical data, spatial interpolation, or machine learning models).

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system performs preliminary actions by pre-calculating and storing signal strength patterns, propagation models, and environmental characteristics in advance. When a dead zone is detected, these pre-computed data and models are quickly applied to generate accurate predictions without requiring real-time complex calculations, enabling seamless passive entry functionality even in areas with no direct signal measurement capability.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If multiple predictors are generated to estimate mobile device location in dead zones, then location accuracy is improved, but computational complexity increases

Engineering Contradiction:
Improvelocation estimation accuracyVSAvoidcomputational complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent implements a hierarchical prediction strategy where multiple predictors are generated but not all are equally weighted or processed. The system uses a combination of simple predictors (e.g., based on recent history) and complex predictors (e.g., machine learning models), activating only the necessary level of complexity based on the situation. This partial action approach achieves sufficient location accuracy without the excessive computational burden of running all possible prediction methods at full capacity simultaneously.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The system incorporates feedback mechanisms where the results from multiple predictors are continuously evaluated and compared. When predictors converge on a consistent location estimate, the system accepts this result. When they diverge, the system adjusts its prediction strategy based on feedback from recent accuracy measurements, environmental conditions, and resource availability, dynamically balancing accuracy requirements with computational constraints.

Inventive Principle:
Principle #23Feedback

Data Source

PatentUS10640087B2Dead zone mitigation for a passive entry system of a vehicle
Publication Date: 2020.05.05 FORD GLOBAL TECH LLC
  • US10640087B2 patent drawing
  • US10640087B2 patent drawing
  • US10640087B2 patent drawing

AI summary

Method and apparatus are disclosed for dead zone mitigation for a passive entry system of a vehicle. An example vehicle includes antenna modules to measure signal strengths of broadcasts from a mobile device. The example vehicle also includes a wireless module to, when the mobile device is in a dead zone, generate first and second predictors and enable passive entry when the first and second predictors match and indicate that the mobile device is in a passive entry zone, and a sensor detects a user. The example vehicle also includes a body control module to unlock a door when passive entry is enabled.