Engine Torque Map Matching for Shift Pattern Drivability
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Solution Overview
Problem
Existing vehicle control systems face issues with drivability due to the lack of torque reserve in all gears, leading to sluggish acceleration and unpredictable responses during gear shifts, as adjusting torque maps without considering gear shift patterns can result in torque saturation and excessive acceleration after downshifts.
Innovation Solution
The method involves matching the vehicle torque map to gear shift patterns by producing 100% of the engine's available torque before a downshift and calculating a second torque for increased power output after the downshift, ensuring a reserve of power and smoother acceleration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If torque map is adjusted without considering gear shift pattern, then torque delivery can be optimized for specific conditions, but drivability deteriorates due to torque saturation and sluggish acceleration response
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing optimal torque values in lookup tables for each gear and accelerator pedal position combination. The system determines the current gear and APS position, then directly retrieves the pre-computed optimal torque value, avoiding real-time complex calculations and enabling responsive torque delivery that adapts to gear shifts.
Solution Approach 2:
The patent implements dynamics by making the torque map adaptive to changing gear conditions. Instead of using a fixed torque map, the system dynamically selects appropriate torque values based on the current gear and accelerator pedal position, allowing the torque delivery characteristics to change smoothly across gear transitions and maintain optimal drivability.
2Device complexity
If constant torque is maintained across all RPM values, then simple control is achieved, but acceleration response becomes sluggish due to lack of torque reserve
Solution Approach 1:
The patent applies local quality by implementing different torque strategies for different operating conditions (gears and accelerator pedal positions). Each combination of gear and APS position has its own optimized torque value in the lookup table, allowing the system to provide aggressive torque delivery when needed (improving acceleration response) while maintaining simple retrieval-based control.
3Speed
If torque map is optimized for performance, then acceleration capability improves, but drivability deteriorates due to excessive acceleration after downshift
Solution Approach 1:
The patent uses preliminary action by pre-calculating torque values that account for upcoming gear shifts. The lookup tables are populated with torque values that anticipate the need for smooth transitions, preventing excessive acceleration after downshifts while maintaining strong acceleration capability. The system retrieves these pre-computed values based on current gear and APS position.
Solution Approach 2:
The patent implements dynamics by making torque delivery adaptive to gear position changes. The system dynamically adjusts torque based on the current gear and accelerator pedal position, allowing smooth transitions during downshifts while maintaining performance. This dynamic adaptation prevents the harsh acceleration spikes that occur with fixed torque maps during gear changes.
Data Source
AI summary
A method includes: controlling a production of torque by an engine of a vehicle such that a first torque is produced in an nth gear prior to a downshift determined according to a gear shifting pattern of the vehicle, wherein the first torque is 100% of the engine's available torque at a given accelerator pedal position and a given engine revolutions per minute (RPM); calculating a second torque which causes a predefined increase in engine power output based on a first engine power output occurring as the engine produces the first torque at the given accelerator pedal position and the given RPM; and controlling the production of torque by the engine such that the second torque is produced in an (n−1)th gear after the downshift.