Hybrid Vehicle Control Method Preventing Battery Overcharge During Upshifts
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In vehicles equipped with internal combustion engines and electric motors, gear upshifts can lead to overcharging of the battery with excess electric power, accelerating battery deterioration.
Innovation Solution
A control method that adjusts the operation of the internal combustion engine, rotation regulator, and transmission to limit charging electric power during gear upshifts, ensuring it remains below a predetermined level, thereby preventing battery overcharge and allowing smooth gear changes while maintaining efficient engine operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the gear of the transmission is upshifted while keeping the engine operation at the efficient drive point, then fuel consumption is improved, but the battery may be overcharged with excess electric power
Solution Approach 1:
The control device performs preliminary action by changing the engine's drive point before the actual gear upshift occurs. When an upshift is detected, the control device adjusts the engine operation point in advance to prevent excessive electric power generation that would otherwise overcharge the battery during the gear transition.
Solution Approach 2:
The control device uses feedback by continuously monitoring the gear state and electric power generation conditions. When the transmission gear state changes (upshift detected), the control device receives this feedback and automatically adjusts the engine drive point to maintain optimal fuel efficiency while preventing battery overcharge.
2Reliability
If the engine drive point is changed to prevent battery overcharge, then battery reliability is improved, but engine operation efficiency may be reduced
Solution Approach 1:
The control device changes the engine drive point in advance before the gear upshift occurs. This preliminary adjustment ensures that when the upshift happens, the electric power generation is already controlled to safe levels, protecting the battery while minimizing the impact on overall engine efficiency.
Solution Approach 2:
The control device applies parameter changes by adjusting the engine's operating parameters (drive point) dynamically. The control device selects appropriate drive points from multiple available options, changing parameters such as injection amount and ignition timing to achieve the desired balance between battery protection and engine efficiency.
3Adaptability or versatility
If multiple drive points are used for the engine, then flexibility in controlling electric power generation is improved, but control complexity increases
Solution Approach 1:
The control device utilizes parameter changes by establishing multiple predetermined drive points with different characteristics. Each drive point represents a specific combination of engine parameters (injection amount, ignition timing, etc.), allowing flexible control of electric power generation without requiring complex real-time calculations.
Solution Approach 2:
The control device performs preliminary action by pre-establishing multiple drive points and their corresponding characteristics before operation. This preparation work simplifies the actual control process, as the control device only needs to select from pre-defined options rather than calculating optimal parameters in real-time during gear transitions.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Prevents battery overcharging during gear shifts, prolongs battery life, and ensures efficient engine operation by controlling the drive point of the internal combustion engine and the transmission, thereby improving fuel consumption and reducing wear on vehicle components.
Implementation Method 1
a rotation regulator that is linked to an output shaft of the internal combustion engine, is connected to a power shaft different from the output shaft to enable rotation of the power shaft independently of the output shaft, and regulates a rotation speed of the output shaft relative to the power shaft through input and output of electric powers
Implementation Method 2
a motor that inputs and outputs power to and from the power shaft
Implementation Method 3
an internal combustion engine
Data Source
AI summary
The control procedure of the invention sets a target rotation speed Ne* and a target torque Te* of an engine corresponding to a torque demand Td* required for driving the vehicle (steps S100 to S120). In response to an upshift request for a gear of a transmission, the control procedure sets a positive pre-upshift target rotation speed Nmtag to a target rotation speed Nm1* of a first motor (step S230). The control procedure changes the target rotation speed Ne* of the engine to a specific rotation speed corresponding to the pre-upshift target rotation speed Nmtag of the first motor (step S240) and subsequently implements an actual change of the gear in the transmission (step S310). This arrangement effectively restrains a battery from being overcharged with excess electric power.