Hybrid Vehicle Engine Control via Dynamic Reference Adjustment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional hybrid vehicle engine control methods lead to inefficient engine operation and reduced acceleration/deceleration responsiveness due to delayed engine start and stop times, caused by hysteresis-based reference value settings that do not accurately reflect real-time driving conditions.
Innovation Solution
A driving control method that calculates an expected vehicle velocity based on driver and road average velocities, determines the driving situation, and adjusts engine-on and engine-off reference values to optimize engine operation, allowing for timely and efficient engine start and stop according to the driving situation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If hysteresis-based engine-on/off reference values are used, then frequent engine start-stop is prevented, but engine operation efficiency deteriorates and acceleration responsiveness is reduced
Solution Approach 1:
The patent applies dynamics by making the engine-on reference value dynamic rather than fixed. The controller adjusts the engine-on reference value based on real-time driving conditions including accelerator pedal opening degree, vehicle speed, and battery state of charge. This allows the system to adapt to changing driving situations, enabling faster engine restart response during acceleration while maintaining stable operation during steady-state conditions.
Solution Approach 2:
The patent changes the parameter of engine-on reference value from a fixed hysteresis-based threshold to a dynamically adjusted value. The controller modifies this reference value according to multiple parameters including accelerator pedal position, vehicle speed, and battery charge state. This parameter change enables the system to optimize both engine stability and acceleration responsiveness by adjusting the reference value based on current operating conditions.
2Reliability
If hysteresis-based engine-on/off control is implemented, then engine start-stop frequency is reduced, but fuel efficiency deteriorates due to extended operation in inefficient regions
Solution Approach 1:
The patent makes the engine-on reference value dynamic, adjusting it based on real-time driving conditions. This allows the system to minimize the time the engine operates in inefficient regions by promptly restarting the engine when driving conditions indicate a need for power, thereby reducing fuel waste while maintaining operational stability.
Solution Approach 2:
The controller predicts future driving power requirements based on current accelerator pedal opening degree and vehicle speed trends. By anticipating increased power demand before it fully manifests, the system can proactively adjust the engine-on reference value to ensure timely engine restart, preventing prolonged operation in inefficient low-power regions and improving overall fuel efficiency.
Data Source
AI summary
A driving control method for a hybrid vehicle is capable of improving fuel efficiency of the hybrid vehicle and increasing acceleration/deceleration responsiveness of the vehicle according to a demand of a driver by more appropriately selecting a point of time at which an engine is turned on/off in the hybrid vehicle in response to a driving situation, and controlling driving of the engine and a motor accordingly.