Sinusoidal Synchronization Pulse Generation for Vehicle Bus EMI Reduction

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Solution Overview

Problem

Current synchronous bus systems in vehicles experience increased electromagnetic radiation due to the high harmonic content of trapezoidal synchronization pulses, which can be mitigated by optimizing the shape of the synchronization pulse to reduce electromagnetic interference.

Innovation Solution

Generating a sinusoidal synchronization pulse using a voltage generator with a current source and current sink, driven by a digital control circuit and digital-to-analog converter, to minimize electromagnetic radiation within specific spectral ranges.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a trapezoidal synchronization pulse is used with high edge steepness, then the synchronization precision is improved, but electromagnetic radiation increases due to high harmonic content

Engineering Contradiction:
Improvesynchronization precisionVSAvoidelectromagnetic radiation
Core Design Contradiction:
Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

The invention changes the waveform parameter from trapezoidal to sinusoidal, fundamentally altering the spectral characteristics. The sinusoidal pulse contains only fundamental frequency components without the high-order harmonics present in trapezoidal waves, thereby reducing electromagnetic radiation while preserving synchronization precision through proper frequency and amplitude control

Inventive Principle:
Principle #35Parameter changes

2Object-generated harmful factors

If a trapezoidal synchronization pulse with rounded corners is used, then electromagnetic radiation is reduced to some extent, but the synchronization precision and signal quality deteriorate

Engineering Contradiction:
Improveelectromagnetic radiationVSAvoidsynchronization precision
Core Design Contradiction:
Object-generated harmful factorsVSMeasurement precision

Solution Approach 1:

The invention implements a complete waveform transformation from trapezoidal to sinusoidal, rather than merely rounding corners. This fundamental parameter change optimizes both electromagnetic compatibility and signal quality simultaneously, as the sinusoidal shape inherently provides smooth transitions without sharp edges while maintaining precise temporal characteristics for synchronization

Inventive Principle:
Principle #35Parameter changes

3Speed

If the edge steepness of the synchronization pulse is increased, then the rise time is reduced and synchronization speed is improved, but electromagnetic interference increases

Engineering Contradiction:
Improvesynchronization speedVSAvoidelectromagnetic interference
Core Design Contradiction:
SpeedVSObject-generated harmful factors

Solution Approach 1:

The sinusoidal waveform inherently provides optimized rise and fall times without requiring high edge steepness. The continuous curved transitions of the sinusoidal shape achieve fast synchronization response while avoiding the abrupt voltage changes that generate electromagnetic interference, thus resolving the contradiction between speed and interference

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

The sinusoidal synchronization pulse reduces electromagnetic radiation to the lowest possible levels, especially in the 100kHz to 300kHz range, by restricting it to the fundamental waves, thereby enhancing signal transmission efficiency.

Implementation Method 1

the voltage generator generates the synchronization pulse via the current source and the current sink by charging and/or discharging a bus load essentially as a sinusoidal oscillation

Methodology Applied
Scientific EffectSinusoidal oscillation: Harmonic Oscillator

Data Source

PatentEP2810399B1Receivng device for a control device in a vehicle et method for generating a synchronisation pulse
Publication Date: 2021.03.10 ROBERT BOSCH GMBH
  • EP2810399B1 patent drawingFigure 1~2
  • EP2810399B1 patent drawingFigure 3~5
  • EP2810399B1 patent drawingFigure 6~7

AI summary

The invention relates to a reception arrangement (3) for a control device in a vehicle with a voltage generator (30) for generating a synchronisation pulse, comprising a first voltage source (3.1), a current source (3.5) and a current sink (3.6), wherein the voltage generator (30) generates the synchronisation pulse within predetermined specification limits with a predetermined shape and a predetermined temporal behaviour, and wherein the reception arrangement (3) outputs the synchronisation pulse for synchronising a signal transmission via a data bus (5) to at least one sensor (7); the invention also relates to a method for generating a synchronisation pulse. According to the invention, the voltage generator (30) generates the synchronisation pulse via the current source (3.5) and the current sink (3.6) by charging and/or discharging a bus load substantially as a sinusoidal oscillation.