Vehicle Comfort Heating With Capacitive Sensing Mode Switching

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing vehicle heating systems lack responsiveness and efficiency in achieving thermal comfort while ensuring safety and reliability of capacitive sensors.

Innovation Solution

A system with a resistive heating structure and capacitive sensor that alternates between heating and detection modes, using PWM signals to control switches, ensuring the capacitive sensor operates effectively without interference from the heating process, and includes a protection temperature to prevent burns.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the capacitive sensor operates continuously during heating, then detection reliability is maintained, but heating speed is reduced due to alternating modes

Engineering Contradiction:

Improvecapacitive sensor detection reliabilityVSAvoidheating speed

Core Design Contradiction:

ReliabilityVSSpeed

Solution Approach 1:

The system performs preliminary heating to reach protection temperature first, establishing a safe thermal baseline before activating the capacitive sensor. This preliminary action ensures that when detection begins, the heating structure is already at a safe temperature, preventing burns during the transition phase.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system implements periodic alternation between heating mode and capacitive detection mode after reaching protection temperature. This periodic action allows the capacitive sensor to operate reliably without continuous interference from heating currents, while minimizing detection intervals to maintain overall heating efficiency.

Inventive Principle:

Principle #19Periodic action

2Temperature

If heating and capacitive detection operate simultaneously, then thermal comfort is maintained, but sensor accuracy deteriorates due to electromagnetic interference

Engineering Contradiction:

Improvethermal comfortVSAvoidcapacitive sensor accuracy

Core Design Contradiction:

TemperatureVSMeasurement precision

Solution Approach 1:

The control unit alternates between heating mode and capacitive detection mode in periodic cycles. During detection periods, heating is temporarily suspended to eliminate electromagnetic interference with the capacitive sensor, ensuring accurate touch detection while maintaining overall thermal comfort through rapid cycle transitions.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The system extracts the capacitive detection function from continuous operation and isolates it to specific time windows when heating is suspended. This separation removes the source of electromagnetic interference during detection, allowing the capacitive sensor to operate independently and accurately.

Inventive Principle:

Principle #2Taking out (Extraction)

3Speed

If the heating structure reaches high temperature quickly, then thermal comfort responsiveness is improved, but burn risk increases

Engineering Contradiction:

Improveheating responsivenessVSAvoidburn risk

Core Design Contradiction:

SpeedVSObject-affected harmful factors

Solution Approach 1:

The system applies preliminary anti-action by first heating to a safe protection temperature (e.g., 60°C) before allowing further heating to higher comfort temperatures. This intermediate safety threshold prevents direct exposure to potentially harmful high temperatures, reducing burn risk while maintaining heating responsiveness.

Inventive Principle:

Principle #9Preliminary anti-action

Solution Approach 2:

The capacitive sensor provides real-time feedback on user contact with the heating structure. When contact is detected, the system immediately suspends heating or reduces power, creating a feedback loop that prevents burns while allowing rapid heating during non-contact periods.

Inventive Principle:

Principle #23Feedback

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

Faster heating to a set temperature is achieved while maintaining capacitive sensor functionality, reducing the risk of burns and electromagnetic interference, and enhancing thermal comfort responsiveness.

Implementation Method 1

at least one resistive layer arranged to produce heat when this layer is traversed by an electric current

Methodology Applied

Scientific EffectJoule effect: Joule Heating

Implementation Method 2

a capacitive sensor arranged to detect, in a detection zone, a presence of a part of a passenger

Methodology Applied

Scientific EffectCapacitive detection: Capacitance

Data Source

PatentEP4590071A1Interactive comfort system, in particular for a vehicle

Publication Date: 2025.07.23 VALEO ELECTRIFICATION

Figure 1~2
Figure 3~4
Figure 5~6

AI summary

The invention relates to an interactive comfort system (400), in particular intended to be installed inside a passenger compartment of a vehicle, in particular a motor vehicle, the system comprising: - a heating structure (401) comprising: o at least one resistive layer (402), o at least two electrodes, - a capacitive sensor (403) arranged to detect, in a detection zone, a presence of a part of a passenger, for example an arm, an elbow, a hand or a finger (FG) of the passenger, - a control unit (410) configured to control the heating structure (401) and the capacitive sensor (403) with a heating mode of the heating structure (401) and a capacitive detection mode of the capacitive sensor (403), system in which the control unit (410) is configured to, in a phase (Dreq) of increasing the temperature of the heating structure (401) in order to reach a predetermined temperature,turn on only the heating mode of the heating structure (401).,