Engine Rev Limiter Torque Control Feedback
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Solution Overview
Problem
Existing rev limiters in high-performance internal combustion engines prematurely limit torque delivery, reducing engine performance by controlling torque based on predicted speed rather than actual speed, leading to delayed reaching of nominal speed and unintended vehicle behavior.
Innovation Solution
Activating feedback control only when the engine reaches or is close to nominal speed, setting a predetermined initial torque that can be adjusted for each gear ratio, and using this torque to stabilize the engine at nominal speed while the feedback control adjusts torque delivery to maintain it, allowing for oscillations to adjust exhaust tone and reduce pollutants.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If feedback control is activated early based on predicted speed, then the engine speed can be limited in advance, but the torque delivery is reduced prematurely and the engine reaches nominal speed later
Solution Approach 1:
The patent applies preliminary action by setting a predetermined initial torque value before the feedback control is activated. This initial torque is calculated based on predicted engine speed progression and is applied in advance to prepare the engine for optimal performance when nominal speed is reached, rather than limiting torque prematurely as in prior art
Solution Approach 2:
The patent implements feedback control that is activated only when the engine reaches or is close to nominal speed, not based on predicted speed as in prior art. The feedback control continuously monitors actual engine speed and adjusts torque delivery to maintain nominal speed, ensuring torque is not reduced until absolutely necessary
2Measurement precision
If feedback control is activated based on predicted speed progression, then the rev limiter can prepare for speed limitation, but the actual torque delivery curve deviates from ideal progression
Solution Approach 1:
The patent inverts the conventional approach by not activating feedback control based on predicted speed, but rather waiting until actual nominal speed is reached or closely approached. This reversal ensures that torque delivery follows the ideal progression curve more closely, as the feedback control only activates when needed, rather than prematurely limiting torque based on predictions
Solution Approach 2:
The patent changes the activation parameter for feedback control from predicted speed to actual nominal speed. Additionally, it introduces a predetermined initial torque parameter that is set optimally to match the ideal torque delivery curve, ensuring natural vehicle behavior while maintaining speed limitation
3Reliability
If the rev limiter limits torque delivery early to prevent exceeding nominal speed, then the engine speed can be controlled, but the time to reach nominal speed is significantly delayed
Solution Approach 1:
The patent applies preliminary action by calculating and setting a predetermined initial torque value that is optimized to bring the engine to nominal speed as quickly as possible. This initial torque is applied before feedback control activation, allowing the engine to reach nominal speed rapidly without premature limitation, thus reducing time loss while maintaining eventual speed control
Solution Approach 2:
The patent ensures continuous useful action by maintaining high torque delivery through the predetermined initial torque setting until the engine actually reaches nominal speed. The feedback control then continuously adjusts torque to maintain nominal speed, ensuring uninterrupted optimal performance rather than intermittent limitation
Data Source
AI summary
A method for limiting a revolution speed of an internal combustion engine (E) of a sports car, the method comprising a first step (Step 1) of acquiring a nominal speed value of said internal combustion engine, a second step (Step 2) of measuring a revolution speed of said internal combustion engine, when (CHK) a measured revolution speed of said internal combustion engine has reached (yes) an activation speed approximately equal to said nominal speed, the method comprising a third step (Step 3) of setting a predetermined initial torque value (a) to be delivered by said internal combustion engine and simultaneously a fourth step (Step 4) of carrying out a feedback control of a torque delivery of said internal combustion engine.