UWB Occupant Sensing via CIR for Position and Vital Sign Detection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current vehicle safety systems face challenges in accurately distinguishing between occupants and objects using pressure sensors alone, necessitating a more precise method to determine occupant position and vital parameters for effective safety system operation.

Innovation Solution

A method utilizing a radio system with ultra-wide band (UWB) antennas and a control unit to perform Channel Impulse Response (CIR) measurements, enabling spatially and time-resolved monitoring of vehicle occupants, including vital parameter measurement like heart rate and breathing rate, through UWB pulses transmission and reception, and storing data for enhanced safety and rescue operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If pressure sensors are used to detect occupant presence, then the system can detect seat occupancy, but it cannot accurately distinguish between occupants and objects

Engineering Contradiction:
Improveoccupant detection accuracyVSAvoidsensor system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines multiple sensing modalities (pressure sensors, capacitive sensors, and radar sensors) into a unified sensor system. This merging allows the system to leverage the strengths of each sensor type while overcoming their individual limitations, enabling accurate distinction between occupants and objects through data fusion from multiple sources.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The radar sensor array is designed to perform multiple functions: detecting occupant presence, determining occupant position, monitoring vital signs, and distinguishing occupants from objects. This multi-functional approach replaces what would otherwise require separate sensor systems, reducing overall system complexity while improving measurement precision.

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

2Measurement precision

If multiple sensors are used to accurately determine occupant position and vital parameters, then measurement precision improves, but device complexity increases

Engineering Contradiction:
Improveoccupant position and vital parameter detection accuracyVSAvoidnumber of sensors required
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The radar sensor array serves multiple purposes simultaneously: it detects occupant presence, determines spatial position, monitors chest movements for breathing rate, and measures heart rate through Doppler effects. This single multi-functional system replaces what would traditionally require separate pressure sensors, capacitive sensors, and dedicated vital sign monitoring devices.

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

Solution Approach 2:

The patent replaces mechanical pressure sensors with electromagnetic radar sensing technology. This substitution enables contactless measurement of occupant position and vital parameters, eliminating the need for physical contact while providing more comprehensive data including precise position tracking and accurate vital sign monitoring without increasing device complexity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If UWB signals are used for occupant monitoring, then measurement precision and minimal interference are achieved, but transmission power requirements increase

Engineering Contradiction:
Improveoccupant detection accuracyVSAvoidtransmission power
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The UWB radar system transmits signals in periodic pulse sequences rather than continuous waves. This periodic transmission allows the system to accumulate measurement data over multiple pulses while keeping individual transmission power low. The pulsed nature of UWB signals enables precise time-of-flight measurements for position determination and Doppler measurements for vital sign detection without requiring high continuous power.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system utilizes the wide bandwidth parameter of UWB signals (at least 500 MHz) to achieve high resolution in both time and frequency domains. This parameter change from narrowband to ultra-wideband signaling enables precise measurement of occupant position and vital parameters while maintaining low transmission power, as the energy is distributed across a wide frequency spectrum rather than concentrated at a single frequency.

Inventive Principle:
Principle #35Parameter changes

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 allows for accurate detection and monitoring of occupants, including vital signs, with minimal interference, enabling precise occupant identification and improved safety responses, especially in accident scenarios, by creating occupant-specific profiles and facilitating emergency access and rescue operations.

Implementation Method 1

A motor vehicle (10) comprises a radio system with a transceiver (13, 15), with a first UWB antenna (14) and with a second UWB antenna (16)... configured to transmit and receive UWB pulses

Methodology Applied
Scientific EffectElectromagnetic radiation: Electromagnetic Induction

Implementation Method 2

the control unit (12) is configured to control the radio system to perform a method based on channel impulse response (CIR) measurements using the first UWB antenna (14) and the second UWB antenna (16)... during operation of the motor vehicle (10)

Methodology Applied
Scientific EffectChannel impulse response measurement: Reflection

Data Source

PatentEP4324706A1Method for determining the position and vital parameters of an occupant of a motor vehicle, and motor vehicle
Publication Date: 2024.02.21 VOLKSWAGEN AG
  • EP4324706A1 patent drawingFigure 1
  • EP4324706A1 patent drawingFigure 2
  • EP4324706A1 patent drawingFigure 3

AI summary

The invention relates to a method for determining the position and vital parameters of an occupant of a motor vehicle (10) and a motor vehicle (10) with a radio system and a control unit (12) connected to the radio system. It is provided that, using at least two UWB antennas (14, 16), a method based on Channel Impulse Response (CIR) measurements is carried out during the operation of the motor vehicle (10) to determine the position and vital parameters of one or more occupants of the motor vehicle (10).