Diesel Glow Plug Temperature Control via Autonomous Target Setting

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Solution Overview

Problem

The existing control systems for diesel engine glow plugs require complex mutual adjustments between the engine control unit and the glow plug control unit, limiting independence and flexibility in design and operation, and do not effectively adapt the glow plug temperature to varying engine conditions, which affects ignition and emissions.

Innovation Solution

The engine control unit specifies a target temperature for the glow element, which is transmitted to the glow plug control unit to implement using stored algorithms and characteristic values, allowing independent operation and adaptive temperature adjustment based on engine conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If complex mutual adjustments between engine control unit and glow plug control unit are implemented, then glow plug temperature control is achieved, but system complexity and control effort increase

Engineering Contradiction:
Improveglow plug temperatureVSAvoidcontrol system complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The glow plug control unit autonomously determines the target temperature for the glow element based on engine operating conditions (coolant temperature, engine speed, load) without requiring complex coordination with the engine control unit. The system serves itself by having the glow plug controller independently make temperature decisions based on stored characteristic values and current engine parameters.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The control system is divided into independent functional segments: the engine control unit handles engine management while the glow plug control unit independently handles glow plug temperature control. This segmentation allows each unit to operate autonomously with simplified interfaces, reducing overall system complexity while maintaining effective temperature control.

Inventive Principle:
Principle #1Segmentation

2Ease of operation

If predetermined temperature control is used, then control implementation is simplified, but adaptability to varying engine conditions is reduced

Engineering Contradiction:
Improvecontrol implementation easeVSAvoidtemperature adaptability
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The target temperature is made dynamic rather than fixed. The glow plug control unit continuously adjusts the target temperature based on real-time engine conditions including coolant temperature, engine speed, and load. This dynamic adaptation allows the system to respond to varying operating conditions while maintaining straightforward control implementation through automated parameter adjustment.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the target temperature parameter according to engine operating conditions. Stored characteristic values provide baseline temperatures that are modified based on current engine parameters, enabling the system to adapt to different operating regimes (cold start, warm operation, high load, idle) without complex control logic.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If glow plug temperature is optimized for immediate ignition, then ignition reliability improves, but service life is reduced

Engineering Contradiction:
Improveignition reliabilityVSAvoidglow plug service life
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The glow plug operation uses periodic heating cycles rather than continuous high-temperature operation. The control unit applies heating voltage in controlled periods to reach target temperatures for ignition support, then reduces or stops heating when target temperature is achieved. This periodic action pattern maintains ignition reliability while reducing cumulative thermal stress on the glow plug element.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system applies partial heating action - using just enough heating voltage and duration to reach the required target temperature for reliable ignition, rather than continuously applying maximum heating power. The control unit monitors temperature and stops heating when the target is reached, avoiding excessive thermal exposure that would reduce service life while maintaining sufficient ignition reliability.

Inventive Principle:
Principle #16Partial or excessive action

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 the effort in controlling glow plugs, optimizes their temperature for improved ignition and reduced emissions, extends their service life, and allows for more flexible engine operation, including supporting combustion over longer periods and reducing pollutant emissions.

Implementation Method 1

controls the electrical power supplied to the glow plugs... rapid heating of the glow plugs during the pre-heating phase is energy-controlled

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

Glow plugs are designed to ensure reliable ignition of the fuel-air mixture... maintain a smooth idle during an afterglow phase

Methodology Applied
Scientific EffectThermal radiation: Thermal Radiation

Data Source

PatentEP1852604B1Method for operating spark plugs in diesel engines
Publication Date: 2019.05.15 BORGWARNER LUDWIGSBURG GMBH
  • EP1852604B1 patent drawingFigure 1

AI summary

The method involves having a housing which is arranged over a glow element. A motor control unit is provided having a glow control device and receives default controls. The engine control unit detects a size which is a measure of temperature of the glow element. The size is transmitted as a target to the glow control device which is an algorithm that is stored. Stored parameters are considered by the algorithms and implemented.