Vehicle Control Unit Thermal Management via Dynamic Switching

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Solution Overview

Problem

Existing control units for vehicle passenger protection systems face challenges in managing thermal loads and electromagnetic radiation from switching converters, leading to interference with radio reception and increased costs from static interference suppression measures.

Innovation Solution

A control unit with an influencing circuit that adjusts the rise and fall times of switching converter output signals based on thermal load, using adjustable current sources and adaptive control to balance thermal stress and radiation, thereby improving electromagnetic compatibility without additional static interference suppression measures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the current is kept constant during the charging phase to avoid overheating, then thermal stability is improved, but electromagnetic radiation increases and interferes with radio reception

Engineering Contradiction:
Improvethermal stabilityVSAvoidelectromagnetic radiation
Core Design Contradiction:
TemperatureVSObject-generated harmful factors

Solution Approach 1:

The patent applies dynamics by making the charging current variable rather than constant. The control unit continuously adjusts the charging current based on real-time temperature measurements from the temperature sensor, creating a dynamic balance between thermal stability and electromagnetic radiation reduction.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements feedback control through a closed-loop system where the temperature sensor monitors the charging phase temperature, the control unit processes this information, and adjusts the charging current accordingly. This feedback mechanism enables the system to maintain thermal stability while minimizing electromagnetic radiation interference.

Inventive Principle:
Principle #23Feedback

2Reliability

If static interference suppression measures such as snubber circuits are added, then electromagnetic compatibility is improved, but device complexity and costs increase

Engineering Contradiction:
Improveelectromagnetic compatibilityVSAvoidcircuit complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies self-service by enabling the switching converter to regulate its own electromagnetic emissions through intelligent control. The control unit uses temperature feedback to dynamically adjust operating parameters, allowing the system to self-regulate electromagnetic compatibility without requiring additional passive suppression components.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent implements parameter changes by dynamically modifying the charging current based on temperature conditions. This active parameter adjustment achieves electromagnetic compatibility through control strategy rather than through additional circuit components, thereby reducing device complexity.

Inventive Principle:
Principle #35Parameter changes

3Temperature

If the charging current is gradually reduced when temperature exceeds threshold, then thermal stability is improved, but charging efficiency decreases

Engineering Contradiction:
Improvethermal stabilityVSAvoidcharging efficiency
Core Design Contradiction:
TemperatureVSProductivity

Solution Approach 1:

The patent applies dynamics by implementing continuous real-time adjustment of the charging current based on temperature measurements. Rather than using fixed threshold-based reduction, the system dynamically optimizes the charging current at each moment, maintaining high charging efficiency while ensuring thermal stability through continuous adaptation.

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

This approach reduces electromagnetic radiation, enhances electromagnetic compatibility, and maintains efficiency by optimizing thermal load and radiation characteristics, particularly in the VHF range, without the need for costly static interference suppression measures.

Implementation Method 1

A switching converter is a converter that transforms an input voltage to a higher or lower voltage level using inductances such as chokes or transformers

Methodology Applied
Scientific EffectElectromagnetic Induction: Electromagnetic Induction

Implementation Method 2

The smoothing of the output voltage takes place usually by capacitors (electrolytic capacitors)

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 3

The physical parameter on the integrated circuit is defined by the dependent claims... The at least one physical parameter is used to determine the thermal load on the integrated circuit

Methodology Applied
Scientific EffectTemperature detection:

Data Source

PatentEP2240347B1Control unit and method for controlling personal protection means for a vehicle
Publication Date: 2018.04.11 ROBERT BOSCH GMBH
  • EP2240347B1 patent drawingFigure 1~3
  • EP2240347B1 patent drawingFigure 4
  • EP2240347B1 patent drawingFigure 5

AI summary

A method and a control unit for controlling personal protection means for a vehicle are proposed, wherein at least one DC-DC converter is used for voltage conversion. An influencing circuit is proposed for the at least one DC-DC converter, wherein the DC-DC converter is disposed in an integrated switching circuit. The influencing circuit determines a thermal load as a function of at least one physical parameter for the integrated switching circuit. Rise and/or fall times of at least one output signal of the at least one DC-DC converter are modified as a function of said thermal load.