Vehicle Lighting Modulation for Distance Measurement

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Solution Overview

Problem

Existing vehicle systems for determining distance to objects require multiple sensors, which increase costs and installation space, and existing lighting systems that double as sensors can be noticeable and distracting.

Innovation Solution

A method and device that utilize the vehicle's existing lighting system, such as LEDs, to generate modulated signals for distance measurement, allowing the lighting system to function both as an illumination source and a sensor, while minimizing visibility to human observers, and adjusting power based on ambient conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If additional sensors (radar, lidar, ultrasound) are used for object detection, then measurement precision and reliability are improved, but device complexity and cost increase

Engineering Contradiction:
Improvedistance measurement precisionVSAvoidsensor system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies multi-functionality by enabling vehicle lighting devices to serve dual purposes: illumination and distance measurement. The lighting device emits modulated light signals that reflect off objects and are detected by sensors, allowing the same component to perform both lighting and sensing functions, thereby eliminating the need for separate dedicated sensors

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent combines the illumination function and sensing function into a single integrated system. The lighting device and sensor work together as a unified distance measurement system, merging what were previously separate components (light source and sensor) into a collaborative functional unit that reduces overall system complexity

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If additional sensors are installed on the vehicle, then object detection capability is improved, but installation space requirements increase

Engineering Contradiction:
Improveobject detection reliabilityVSAvoidinstallation space
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The patent makes existing lighting devices multi-functional by adding sensing capability to them. This eliminates the need for separate sensor installations, as the lighting devices themselves perform both illumination and object detection functions, thereby maintaining reliability without increasing installation space requirements

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Measurement precision

If modulated light signals are used for distance measurement, then measurement precision is improved, but visibility to human observers increases causing distraction

Engineering Contradiction:
Improvedistance measurement precisionVSAvoidobserver distraction
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent applies parameter changes by modulating the light signal at specific frequencies that are imperceptible to human observers. The modulation frequency is selected within a range that allows precise distance measurement through phase detection while remaining below the threshold of human visual perception, thus eliminating distraction

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses periodic modulation of the light signal at high frequency. The light is emitted in a periodically modulated manner where the modulation period is so short that human eyes cannot perceive the flicker, yet the periodic signal allows for precise distance measurement through phase comparison between transmitted and reflected signals

Inventive Principle:
Principle #19Periodic action

4Loss of information

If transmission power is increased for distance measurement, then measurement range is improved, but energy consumption increases

Engineering Contradiction:
Improvemeasurement rangeVSAvoidenergy consumption
Core Design Contradiction:
Loss of informationVSUse of energy by moving object

Solution Approach 1:

The patent applies dynamics by adaptively adjusting the transmission power based on ambient light conditions. The system dynamically modifies the modulation depth and transmission intensity according to the surrounding environment, using higher power only when necessary (e.g., in dark conditions) and lower power when ambient light is sufficient, thereby optimizing the balance between measurement range and energy consumption

Inventive Principle:
Principle #15Dynamics

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

Enables cost-effective and unobtrusive distance measurement, reducing sensor complexity and visibility, while maintaining the primary lighting function, and providing accurate distance data for driver assistance systems.

Implementation Method 1

Light emitted by the lighting device and reflected by an object in the scene is received

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 2

the solid-state camera can convert the light reflected from the object into charges

Methodology Applied
Scientific EffectPhotoelectric conversion: Photoelectric Effect

Data Source

PatentEP2956799B1Determining distance information for a vehicle
Publication Date: 2018.09.05 VOLKSWAGEN AG
  • EP2956799B1 patent drawingFigure 1
  • EP2956799B1 patent drawingFigure 2
  • EP2956799B1 patent drawingFigure 3~4

AI summary

The invention relates to a method for a vehicle (10) in order to determine distance information for the vehicle (10). In the method, an operating state of the vehicle (10) is detected, and a modulated signal is generated dependent on the operating state. An illuminating device (11) of the vehicle (10) is actuated dependent on the modulated signal in order to illuminate a scene in an area surrounding the vehicle (10) or a scene within the vehicle (10). Light (16) which has been emitted by the illuminating device (11) and has been reflected by an object (17) in the scene is received, and a reception signal is generated dependent on the received light (16). The distance information, for example a distance between the object (17) and the vehicle (10), is determined dependent on the modulated signal and the reception signal.