Turbocharged Vehicle Launch Control to Reduce Turbo-Lag
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Solution Overview
Problem
Turbocharged engines in vehicles like snowmobiles and ATVs experience delays in efficiency boost and air flow reduction during initial acceleration due to turbocharger spooling-up time, known as turbo-lag, which hinders initial acceleration performance.
Innovation Solution
Implementing a 'launch control' mode that increases engine speed and opens the throttle valve while the vehicle is at rest, allowing the turbocharger to spool-up before acceleration, and using engine speed and torque limiting techniques by adjusting ignition timing and deactivating cylinders to prevent premature acceleration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the turbocharger is used to compress air for improved combustion efficiency, then the engine efficiency is improved, but the initial acceleration is slowed due to turbo-lag
Solution Approach 1:
The system performs preliminary action by spooling up the turbocharger before the vehicle begins acceleration from rest. The controller detects when the vehicle is stationary and actively rotates the turbocharger to build boost pressure in advance, so that when acceleration begins, the turbocharger is already at optimal operating speed and can immediately provide compressed air for efficient combustion without causing turbo-lag.
2Use of energy by moving object
If the turbocharger spools up before acceleration, then combustion efficiency is improved, but air flow to the engine is reduced during spooling
Solution Approach 1:
The system applies dynamics by making the throttle valve position dynamic and adaptive during the spooling process. The controller adjusts the throttle valve opening based on real-time conditions, optimizing the balance between allowing sufficient air flow to the engine during turbocharger spool-up and maintaining conditions that enable the turbocharger to reach optimal speed for efficient combustion.
3Speed
If the throttle is opened and engine speed is increased to spool up the turbocharger, then turbocharger boost is available for acceleration, but the vehicle may accelerate prematurely while still at rest
Solution Approach 1:
The system applies preliminary anti-action by implementing countermeasures to prevent premature vehicle movement before the operator intends to accelerate. The controller detects conditions that would cause unintended acceleration (such as high engine speed and torque at rest) and applies opposing control actions, such as adjusting ignition timing or modulating fuel injection, to neutralize the harmful effect and maintain vehicle stability during the turbocharger spool-up phase.
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 enables faster acceleration from rest with turbocharger boost available immediately, reducing turbo-lag and maintaining acceleration power without time lost to spooling up, resulting in improved initial acceleration performance.
Implementation Method 1
the efficiency of the combustion process can be increased by compressing the air entering the engine. This can be accomplished using a turbocharger connected to the air intake and exhaust systems
Implementation Method 2
causing inefficient ignition which is produced by adjusting the ignition angle to delay combustion ignition in one or more cylinders
Data Source
AI summary
A method for accelerating a vehicle from rest, including controlling an engine according to a first control strategy; receiving a mode indication selecting a launch control mode for accelerating; controlling the engine according to a second control strategy; in response to greater than zero accelerator position, controlling to increase throttle valve opening and engine control operational conditions to limit engine torque output; while in the second control strategy, receiving an indication to end control by the second control strategy; and in response to indication, controlling according to the first control strategy causing the vehicle to accelerate from rest, the first acceleration rate greater than the second rate corresponding to accelerating from rest after sequentially controlling according to the first and second control strategies; the second acceleration rate corresponding to accelerating from rest by controlling according to the first control strategy without previously controlling according to the second control strategy.