Hybrid Engine Start Controller Torque Compensation
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Solution Overview
Problem
In hybrid vehicle systems, the difference in output characteristics between starters and motor generators leads to inadequate or excessive fuel injection during engine start-up, as the existing engine start controllers do not account for the distinct rotational torque capabilities of these components.
Innovation Solution
An engine start controller that calculates an assist injection amount based on the engine's rotation speed, adjusting fuel injection to match the torque requirements of either the starter or motor generator, ensuring adequate starting torque while minimizing fuel consumption by setting the assist injection amount to zero when the motor generator's torque exceeds the needed torque.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the same fuel injection amount is used for both starter and motor generator engine starting, then the engine can be started reliably using the starter, but fuel consumption increases excessively when using the motor generator
Solution Approach 1:
The fuel injection amount is made dynamic by adjusting it according to the engine rotation speed and the type of starting device being used. The control device calculates different assist injection amounts based on whether the starter or motor generator is initiating engine start, allowing the system to adapt fuel delivery to the specific torque characteristics of the active starting device.
Solution Approach 2:
The system changes the fuel injection parameter (assist injection amount) based on the operating conditions - specifically the engine rotation speed and starting device type. By modifying this key parameter according to the torque capabilities of the active starting device, the system optimizes fuel consumption while maintaining reliable engine starting.
2Force
If a larger fuel injection amount is used during engine start-up, then the starting torque is sufficient, but fuel consumption increases
Solution Approach 1:
The system applies partial fuel injection (assist injection) only during the specific period when the engine rotation speed is below the predetermined threshold. By limiting fuel injection to this critical period and adjusting the amount based on actual torque needs, the system provides sufficient starting torque without excessive fuel consumption throughout the entire start-up process.
Solution Approach 2:
The control device continuously monitors engine rotation speed and uses this feedback to adjust the assist injection amount in real-time. When the rotation speed exceeds the threshold, the system automatically reduces or stops assist injection, creating a closed-loop control system that optimizes fuel delivery based on actual engine performance and torque requirements.
3Use of energy by moving object
If the assist injection amount is reduced when using the motor generator, then fuel consumption decreases, but engine starting reliability may be compromised
Solution Approach 1:
The system dynamically adjusts the assist injection amount based on the interaction between motor generator torque and engine rotation speed. By continuously adapting the fuel injection rate to match the actual torque delivery characteristics of the motor generator during the start-up process, the system maintains reliable engine starting while minimizing fuel consumption.
Solution Approach 2:
The control device changes the assist injection parameter according to the specific operating conditions during motor generator starting. By modifying the injection amount based on engine rotation speed and torque requirements, the system ensures reliable engine starting with the motor generator while avoiding excessive fuel consumption that would occur with fixed injection amounts designed for starter operation.
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
This solution enables reliable and smooth engine starting while reducing fuel consumption by accurately compensating for the torque shortfall or surplus, optimizing fuel injection based on the engine's rotation speed and the torque capabilities of the starter and motor generator.
Implementation Method 1
an injection amount calculating portion configured to calculate, as an assist injection amount, an injection amount of fuel injected from a fuel injection valve of the engine in an engine start-up period until the engine rotation speed exceeds a predetermined starting rotation speed from zero
Data Source
AI summary
An engine start controller includes an injection amount calculating portion that is configured to calculate, as an assist injection amount, an injection amount of fuel injected from a fuel injection valve of an engine in an engine start-up period until the engine rotation speed exceeds a predetermined starting rotation speed from zero. The injection amount calculating portion is configured such that, in a case in which the rotation speed of the engine is higher than or equal to a threshold value that is a value less than the starting rotation speed, the injection amount calculating portion calculates the assist injection amount to be smaller when the engine is started by using the motor generator than when the engine is started by using the starter.