Engine Start Controller Using Integrated Driving Force Threshold
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Solution Overview
Problem
Existing vehicle systems experience wasteful fuel consumption due to repeated starting and stopping of the engine when the target driving force briefly exceeds and then falls below a threshold, leading to inefficient engine operation.
Innovation Solution
An engine start controller that derives an integrated value by integrating the difference between the target driving force and a predetermined threshold value, only starting the engine when the integrated value meets a second threshold, thereby preventing unnecessary engine startups and maintaining the engine in a stopped state when the target driving force is transiently above the first threshold.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the engine is started whenever the target driving force exceeds a predetermined threshold value, then the vehicle can respond quickly to acceleration requests, but the engine will be repeatedly started and stopped causing wasteful fuel consumption
Solution Approach 1:
The system performs preliminary integration of the target driving force before triggering engine start. Instead of immediately starting the engine when the threshold is exceeded, the controller accumulates the driving force values over time and only starts the engine when the integrated value reaches a predetermined threshold, preventing premature or unnecessary engine startups
Solution Approach 2:
The integrated value acts as an intermediary parameter between the target driving force and the engine start command. Rather than directly comparing the instantaneous target driving force with the start threshold, the system uses the integrated value as a mediating criterion that filters out transient fluctuations and provides a more stable trigger condition
2Loss of energy
If the engine is stopped when the target driving force falls below a threshold value to save fuel, then fuel efficiency improves, but the engine may be repeatedly started and stopped reducing reliability
Solution Approach 1:
The system accumulates driving force data before making stoppage decisions. By integrating the target driving force over a period and comparing the accumulated value against a threshold, the system ensures that stoppage decisions are based on sustained low demand rather than transient conditions, improving operational stability
Solution Approach 2:
The stoppage threshold is made dynamic by linking it to the integrated value of the target driving force. Rather than using a fixed threshold, the system adapts the stoppage criterion based on the accumulated driving demand, allowing flexible yet stable engine management that responds to actual usage patterns
Data Source
AI summary
A vehicle includes an engine and an engine start controller. The engine start controller is configured to derive an integrated value while a target driving force derived on a basis of an accelerator operation amount is larger than or equal to a predetermined first threshold value from a time point when the target driving force becomes larger than or equal to the first threshold value, and to start the engine when the integrated value becomes larger than or equal to a predetermined second threshold value. The integrated value is obtained by integrating a difference value between the target driving force and the first threshold value.