Hybrid Vehicle Torque Fluctuation Compensation via Retardation Timing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In hybrid electric vehicles, the control apparatus faces challenges in compensating for torque fluctuations caused by internal combustion engine output changes, particularly when the electrical storage device's power capacity is limited, leading to inefficient compensation and rapid output changes.
Innovation Solution
A control apparatus that adjusts the retardation timing of the stop and combustion energy processes in the internal combustion engine in accordance with the state of the electrical storage device, utilizing the rotating electrical machine to manage torque fluctuations by varying the retardation amount based on charge-discharge power and charging rate, and adjusting the timing of these processes to minimize output changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the stop process is performed to compensate for torque decrease, then torque compensation is achieved, but rapid output change occurs due to response delay in combustion energy amount increase
Solution Approach 1:
The control apparatus performs preliminary action by increasing the combustion energy amount in advance before the stop process is executed. This ensures that when combustion is stopped in one or more cylinders, the other cylinders are already operating at increased energy levels, preventing rapid output changes and maintaining smooth torque compensation.
2Stability of the object's composition
If the motor-generator is used to absorb torque, then torque fluctuation is reduced, but compensation is insufficient when electrical storage device power capacity is limited
Solution Approach 1:
The control apparatus segments the torque compensation function between the internal combustion engine and the motor-generator. The engine handles base torque requirements through combustion energy management in multiple cylinders, while the motor-generator provides supplementary torque adjustment. This segmentation allows effective compensation even when the electrical storage device has limited power capacity.
3Power
If combustion control is stopped in one or more cylinders, then output reduction is achieved for torque management, but discontinuous output change occurs
Solution Approach 1:
The control apparatus maintains continuity of useful action by coordinating the stop process with combustion energy amount increase in other cylinders. When combustion is stopped in one or more cylinders, the energy increase in remaining cylinders compensates for the lost output, ensuring continuous and smooth power delivery without discontinuous changes.
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
Effectively compensates for torque fluctuations by optimizing the retardation timing and combustion energy management, enhancing the controllability and responsiveness of the vehicle's output, even under limited electrical storage device conditions.
Implementation Method 1
an electrical storage device that is charged and discharged by the rotating electrical machine
Implementation Method 2
a rotating electrical machine that applies motive power to a driving wheel
Implementation Method 3
an internal combustion engine that applies motive power to the driving wheel
Data Source
AI summary
A CPU performs a regeneration process of stopping combustion control in one or some of cylinders and making the air-fuel ratio of an air-fuel mixture in the other cylinders or cylinder richer than a theoretical air-fuel ratio, when the amount of PM collected by a GPF increases. In performing the regeneration process, the CPU itself compensates for a fall in the output of an internal combustion engine by gradually increasing the filling efficiency of the other cylinders or cylinder. It should be noted, however, that since the output of the internal combustion engine temporarily fluctuates, the CPU compensates for the fluctuations through the use of a second motor-generator. The CPU varies the retardation amount of a timing of starting the regeneration process with respect to a timing of gradually increasing the filling efficiency, in accordance with the state of a battery.