Hybrid Vehicle Engine Start Threshold Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hybrid vehicles with externally chargeable batteries face delayed engine start times during sudden high-load conditions, leading to slow acceleration responses due to prioritizing battery power over fuel, which compromises acceleration performance compared to ordinary hybrid vehicles.
Innovation Solution
A control device that dynamically adjusts the engine start threshold based on required drive torque, vehicle speed, and residual battery electricity, allowing for earlier engine activation during rapid acceleration requests while maintaining reduced fuel consumption by maximizing battery power usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the engine start threshold is increased to prioritize battery power usage and reduce fuel consumption, then fuel economy improves, but acceleration response deteriorates due to delayed engine start during sudden high-load conditions
Solution Approach 1:
The engine start threshold is made dynamic rather than fixed. The control device adjusts the threshold in real-time based on vehicle operating conditions: it increases the threshold during normal driving to prioritize battery power and reduce fuel consumption, but decreases the threshold during sudden acceleration requests (when accelerator position changes rapidly) to ensure rapid engine start and maintain acceleration response. This dynamic adjustment resolves the contradiction by allowing the system to optimize for fuel economy during steady-state operation while maintaining acceleration performance when needed.
Solution Approach 2:
The control device changes the parameter of engine start threshold based on detected operating conditions. When rapid acceleration is detected (large change in accelerator position), the threshold parameter is decreased to enable earlier engine start. During normal operation, the threshold parameter is increased to maximize battery power usage. This parameter change strategy allows the system to switch between fuel economy mode and acceleration response mode as needed.
2Use of energy by moving object
If the engine start threshold is set high to maximize battery power usage during low-speed driving, then fuel consumption reduces, but engine start is delayed until vehicle speed increases, slowing acceleration response
Solution Approach 1:
The control device performs preliminary detection of accelerator position changes to anticipate the driver's acceleration request. When a large change in accelerator position is detected, the system proactively decreases the engine start threshold in advance, preparing for potential rapid acceleration needs before the vehicle actually begins to accelerate. This preliminary action prevents engine start delay while still allowing battery power to be used during normal low-speed operation.
Solution Approach 2:
The control device continuously monitors accelerator position and uses this feedback to adjust the engine start threshold. When the accelerator position changes significantly, indicating the driver wants to accelerate, the feedback mechanism triggers a threshold decrease to enable rapid engine start. This closed-loop feedback ensures the system responds appropriately to driver intentions while maintaining fuel economy during normal operation.
Data Source
AI summary
A hybrid vehicle includes a motor generator used for driving the vehicle, an engine used in combination with the motor generator, an accelerator sensor arranged in an instructing unit instructing increase and decrease in required drive torque, and a control device starting the engine when a required engine output value exceeds a start threshold. The controller decreases the start threshold according to at least increase in required drive torque, and preferably decreases the start threshold further according to decrease in vehicle speed sensed by a vehicle speed sensor.