Adaptive Powertrain Torque Blending for Smooth Mode Transitions
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Solution Overview
Problem
Existing vehicle control systems experience disconcerting changes in engine torque response when automatically switching between terrain modes, leading to unexpected acceleration or deceleration characteristics, which can be distracting and inconvenient for drivers.
Innovation Solution
A method and system that progressively blends between different filters applied to propulsion requests, allowing for a gradual change in the delay of engine response when switching between vehicle operating modes, ensuring a smooth transition in torque characteristics without sudden changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the vehicle control system automatically switches between terrain modes, then the vehicle can adapt to different driving conditions, but the engine torque response changes abruptly causing driver discomfort
Solution Approach 1:
The system dynamically adjusts the filter time constant based on the current terrain mode, allowing the engine torque response characteristics to change adaptively. Different terrain modes (rock crawl, sand, mud, snow, ice, pavement) have different filter time constants that optimize performance for each condition while maintaining smooth transitions through progressive blending.
Solution Approach 2:
The system changes the filter time constant parameter according to the detected terrain mode. By modifying this key parameter, the system achieves different engine response characteristics suitable for various terrains without requiring complex mechanical changes, and uses progressive blending to transition between parameter values smoothly.
2Speed
If the engine responds immediately to accelerator pedal changes, then the vehicle has responsive acceleration, but the transition between terrain modes causes unexpected acceleration or deceleration
Solution Approach 1:
The system applies a filter to the engine torque response that anticipates the need for smooth transitions. By pre-adjusting the filter time constant before and during mode transitions, the system prevents abrupt changes in acceleration while maintaining overall responsiveness to driver input.
Solution Approach 2:
The filter acts as an intermediary between the accelerator pedal input and the engine torque output. This intermediary component smooths out abrupt changes during terrain mode transitions while preserving the essential responsiveness of the engine to driver demands.
3Productivity
If different filter time constants are used for different terrain modes, then the engine response can be optimized for each terrain, but the switching between filters causes abrupt changes in torque characteristics
Solution Approach 1:
Instead of abruptly switching between fixed filter time constants, the system dynamically adjusts the filter time constant through progressive blending. The transition between different terrain mode filters is achieved by gradually changing the filter characteristic over time, maintaining both optimization for current terrain and stability during transitions.
Solution Approach 2:
The system maintains continuous and smooth engine torque delivery during terrain mode transitions by progressively blending between filter time constants. This ensures that the useful action of engine power delivery continues without interruption or abrupt changes, optimizing performance while maintaining consistency.
Data Source
AI summary
Embodiments of the present invention provide a vehicle having different operating modes, and for each such mode a different characteristic of output torque and accelerator pedal position. The rise of output torque in response to a propulsion request is more or less delayed according to the instant operating mode. The invention provides for blending of the response to a propulsion request so that the delay is progressively varied between a source and target operating mode.