Alternator Control via Engine Speed Derivative
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for controlling an alternator in a motor vehicle with a non-automated gearbox during deceleration are inefficient, as they require gear shift detection sensors and can lead to false detections and delayed battery recharging due to prolonged calculation times, which are not economically viable and affect driver comfort.
Innovation Solution
A method that determines the increase in engine speed during gear reduction changes and initiates alternator ballasting before the end of gear shift recognition, using the derivative of engine speed to anticipate the start of ballasting, even without gear sensors, allowing the alternator to recharge the battery during vehicle deceleration by coupling and decoupling the engine from the gearbox via a clutch.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If gear shift detection sensors and prolonged calculation methods are used to detect gear changes, then gear shift detection accuracy is improved, but response time increases and false detections occur
Solution Approach 1:
The system performs preliminary analysis of engine speed trends and calculates the derivative before the gear shift is complete. By anticipating the gear shift event based on engine speed patterns and initiating ballasting early, the system reduces response time without sacrificing detection accuracy. The method prepares the ballasting operation in advance based on predicted gear shift occurrence.
2Reliability
If alternator ballasting is delayed until gear shift recognition is complete, then false detections are avoided, but the duration of ballasting phase is reduced
Solution Approach 1:
The system initiates alternator ballasting before the gear shift recognition is fully complete by analyzing engine speed derivative trends. This preliminary action extends the ballasting duration while maintaining reliability through continuous monitoring of engine speed patterns that confirm the gear shift is actually occurring, thus avoiding false detections.
Solution Approach 2:
The system dynamically adjusts the ballasting activation timing based on real-time engine speed and its derivative. By using dynamic thresholds and continuous monitoring of engine behavior patterns, the system can safely activate ballasting earlier while still detecting false gear shifts and preventing incorrect operation.
3Loss of time
If engine speed calculation and derivative analysis are performed during gear change, then ballasting can be initiated earlier, but computational complexity increases
Solution Approach 1:
The engine control unit performs multiple functions simultaneously: it monitors engine speed for normal control purposes, calculates the derivative for gear shift detection, and triggers ballasting operation. By making the ECU multi-functional and reusing existing sensor data and processing capabilities, the system avoids adding dedicated hardware or complex separate systems while still achieving early ballasting initiation.
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 method extends the duration of alternator ballasting phases, reduces fuel consumption, and minimizes false gear shift detection errors, enabling efficient energy recovery during engine braking without the need for specific sensors, resulting in significant time and fuel savings.
Implementation Method 1
an alternator associated with a heat engine of a motor vehicle... intended to recharge a battery of the vehicle
Implementation Method 2
coupling and decoupling the engine from the gearbox via a clutch
Data Source
Figure 1~4
Figure 5
AI summary
A method for controlling an alternator combined with a motor vehicle combustion engine, including a phase of loading the alternator, this loading phase being intended to recharge a battery of the vehicle during a period of deceleration of the vehicle. The method comprises a step of determining the increase (TRC, TFS) in engine speed when the injection of fuel into the engine is cut off during a gear reduction change in a gearbox of the vehicle and a step of starting the loading (C4) of the alternator, this loading being initiated when the variation in the increase in engine speed is sufficient after an engine idling period (TRI) occurring during said gear reduction change, before data acknowledging the end of the gear reduction change is available.