Internal Combustion Engine Torque Fluctuation Control
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Solution Overview
Problem
Existing methods for reducing fuel consumption in internal combustion engines, such as high gear ratios and stop-start systems, are not effective for vehicles that spend most of their time at constant cruising speeds, leading to increased maintenance costs and reduced dynamic qualities, and result in power losses and increased fuel consumption.
Innovation Solution
A method that controls the engine to deliver torque fluctuating around a desired value by alternating between active and passive phases, with the engine working in low specific consumption areas and disconnecting from the driveline during passive phases, using a PWM technique to manage fuel supply and maintain vehicle speed stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If high gear ratio is used to reduce fuel consumption, then fuel consumption is reduced, but engine elasticity is reduced and torque reserves are insufficient to face slopes
Solution Approach 1:
The patent applies periodic action by alternating between active phase (engine connected to driveline, delivering torque) and passive phase (engine disconnected from driveline, consuming minimal energy). This periodic switching allows the engine to operate at optimal fuel consumption points while maintaining vehicle motion through coasting during passive phases, thereby reducing overall fuel consumption without permanently sacrificing engine elasticity.
Solution Approach 2:
The system dynamically switches between different operating states (active/passive phases) based on real-time conditions such as vehicle speed, load, and driver demand. This dynamic adaptation enables the engine to maintain high elasticity when needed (by transitioning to active phase) while achieving fuel savings during suitable conditions, resolving the contradiction between fixed high gear ratio efficiency and adaptive engine responsiveness.
2Adaptability or versatility
If number of gears is increased or dual clutch transmission is used to maintain engine elasticity, then engine elasticity is improved, but purchase and maintenance costs increase
Solution Approach 1:
The patent extracts the need for complex transmission systems by implementing engine disconnection from the driveline during passive phases. This allows the vehicle to coast without engine power while maintaining simplicity in transmission design, eliminating the requirement for additional gears or dual clutch mechanisms while preserving engine elasticity through controlled reconnection when needed.
3Use of energy by moving object
If long gearbox ratios are used to reduce fuel consumption, then fuel consumption is reduced, but turbosupercharger response is slower and counter-pressure at exhaust increases at high RPM
Solution Approach 1:
By implementing periodic active and passive phases, the system allows the turbosupercharger to operate at optimal speeds during active phases without the constraint of long gearbox ratios. During passive phases, the engine disconnects from the driveline, allowing the turbosupercharger to spin down and reduce counter-pressure, thereby improving response speed while maintaining fuel efficiency benefits.
Data Source
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AI summary
Method for controlling an internal combustion engine comprising a step of controlling a torque delivery of the engine, by means of a modulation of the engine fuel supply, wherein the modulation is realized by means of a periodical or an aperiodical modulating function, in particular the torque delivery control is of the PWM type.