Engine Torque Reserve for Drag Racing Transient Response
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Solution Overview
Problem
High-performance vehicles with high horsepower engines struggle to quickly transfer engine torque to the ground during brake launches from a complete stop, particularly in drag racing scenarios, due to limitations in existing traction control systems.
Innovation Solution
A control system that generates a torque reserve by increasing airflow and deactivating a predetermined set of engine cylinders, then releases this reserve upon detecting the driver's intent to launch, optimizing torque transfer through enhanced airflow control and reactivation of cylinders.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If existing traction control systems are used to improve torque transfer, then vehicle traction is increased, but the systems are overpowered by high horsepower engines and cannot quickly transfer all engine torque to the ground
Solution Approach 1:
The system performs preliminary action by pre-positioning the engine operating point at a higher airflow level than needed for the current torque request. This creates a reserve of airflow capacity that can be immediately utilized when launch conditions arise, allowing the engine to quickly deliver maximum torque without waiting for airflow adjustments during the launch event.
Solution Approach 2:
The system dynamically adjusts engine operation by temporarily increasing airflow above the steady-state requirement and deactivating specific cylinders. This dynamic modification of the engine's operating characteristics allows rapid torque delivery when needed while maintaining normal operation during non-launch conditions.
2Power
If airflow is increased to achieve maximum torque output, then engine torque is maximized, but the vehicle cannot quickly transfer this torque to the ground due to driveline limitations
Solution Approach 1:
The system pre-conditions the engine by establishing an elevated airflow state before the launch event. This preliminary action ensures that when the driver requests maximum torque, the engine can immediately deliver it without delay for airflow adjustment, effectively bridging the gap between engine capability and driveline transfer capacity.
Solution Approach 2:
The system changes the airflow parameter to a higher-than-necessary level for the current torque request. This parameter modification creates a reservoir of available airflow that can be rapidly converted into torque when launch conditions are detected, enabling faster torque delivery to match the driveline's transfer capability.
3Power
If all cylinders are activated for maximum torque, then engine power is maximized, but noise/vibration/harshness increases during launch preparation
Solution Approach 1:
The system segments the cylinder operation by selectively deactivating specific cylinders (e.g., alternating cylinders) during the torque reserve buildup phase. This segmentation reduces the total number of active combustion events, thereby reducing noise and vibration while the engine prepares for launch. When the launch occurs, all cylinders are reactivated to deliver maximum power.
Solution Approach 2:
The system performs preliminary cylinder deactivation as part of the torque reserve establishment process. By deactivating cylinders before the launch event, the system reduces harmful noise and vibration during the preparation phase while still maintaining the capability to deliver maximum torque when needed.
Data Source
AI summary
A control system and method for controlling vehicle launch includes receiving a request to enable a launch control feature of a traction control system of the vehicle, the launch control feature being configured to improve torque transfer from an engine of the vehicle to a driveline of the vehicle; and in response to receiving the enable request for the launch control feature, generating a torque reserve at the engine by (i) increasing airflow into the engine to a level greater than a level for achieving a torque request for the engine and (ii) deactivating a predetermined set of cylinders of the engine by disabling their respective fuel injectors; detecting an intent of the driver to launch the vehicle; and in response to detecting the intent of the driver to launch the vehicle, releasing the torque reserve to increase a torque output of the engine based on the engine torque request.