Engine Ignition Timing Adjustment Using Thermal State Estimation
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Solution Overview
Problem
Existing ignition timing adjustment methods in internal combustion engines fail to account for transient operating conditions, leading to unnecessary delays that reduce engine performance and increase the risk of knock phenomena due to temperature variations during non-stationary operations.
Innovation Solution
An apparatus and process that adjusts ignition timing based on real-time temperature estimation of engine blocks using a heat exchange model, incorporating transducers for pressure, engine speed, and conditioning fluid temperature, allowing for advanced ignition timing to optimize performance without knock risks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If ignition timing is advanced to increase brake torque and engine performance, then power output is improved, but knock phenomena occur due to increased temperature and pressure
Solution Approach 1:
The ignition timing is made dynamically adjustable rather than fixed, allowing the system to optimize the spark advance angle based on real-time operating conditions. The control unit modifies ignition timing in response to detected engine parameters (intake manifold pressure, coolant temperature, throttle position) to maintain optimal performance while preventing knock under varying load and temperature conditions
Solution Approach 2:
The system implements feedback control by using knock detection means to monitor for knock phenomena and automatically adjusting the ignition timing accordingly. When knock is detected, the control unit retards the ignition timing to eliminate the harmful vibrations, creating a closed-loop control system that maintains optimal operation while preventing damage
2Reliability
If ignition timing is delayed to prevent knock phenomena, then engine safety is improved, but brake torque and performance decrease
Solution Approach 1:
The system dynamically adjusts ignition timing based on actual operating conditions rather than using a conservative fixed timing. By continuously monitoring engine parameters and detecting knock in real-time, the system can operate at optimal advance angles during normal conditions and only retard timing when actually needed to prevent knock, thereby maintaining maximum power output while ensuring reliability
Solution Approach 2:
The control unit changes the ignition timing parameter in response to detected engine conditions. The system monitors intake manifold pressure, coolant temperature, and throttle position to determine appropriate timing adjustments, allowing optimal ignition timing under different operating conditions while preventing knock when necessary
3Device complexity
If fixed ignition timing is used to simplify control system, then device complexity is reduced, but engine performance is lost during transient conditions due to temperature variations
Solution Approach 1:
The system uses the engine's own operating parameters (intake manifold pressure, coolant temperature, throttle position) as feedback signals to automatically adjust ignition timing. This self-service approach allows the control system to adapt to transient conditions using readily available sensor data, maintaining optimal performance without requiring complex external control mechanisms
Solution Approach 2:
The control unit performs multiple functions: it monitors multiple engine parameters (intake manifold pressure, coolant temperature, throttle position), determines optimal ignition timing based on these inputs, detects knock phenomena, and adjusts timing accordingly. This multi-functional approach consolidates control complexity into a single unit that handles both performance optimization and knock prevention
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
Enhances engine performance and efficiency by advancing ignition timing according to actual engine temperature, reducing the risk of knock phenomena and maintaining optimal operation during transient conditions without additional temperature sensors.
Implementation Method 1
a) storing a heat exchange model for a combustion chamber of the engine
Implementation Method 2
estimating, by means of the three determined quantities and by means of the heat exchange model, a fourth quantity indicative of a temperature of at least one engine block delimiting the combustion chamber
Data Source
Figure 1
Figure 2
AI summary
A process to adjust the ignition timing of an air-fuel mixture in a combustion chamber (6) of an internal combustion engine (2) , the process comprises determining a first quantity indicative of a pressure of the mixture for a cycle of the engine, determining a second quantity indicative of a speed of the engine (2), determining a third quantity indicative of a first temperature of a conditioning fluid, providing a heat exchange mathematical model for the combustion chamber (6), which maps the three quantities from the first to the third one onto a fourth quantity indicative of a second temperature of a wall portion (3, 5) around the combustion chamber (6), estimating the fourth quantity by means of the three determined quantities and by means of the mathematical model, and adjusting the ignition timing as a function of the fourth estimated quantity.