Hybrid Vehicle Engine Starting Control for PM Emission Reduction
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Solution Overview
Problem
Hybrid vehicles face excessive particulate matter (PM) emissions during engine starting, depending on the starting method, which is not effectively mitigated by existing control systems.
Innovation Solution
A control system for hybrid vehicles that includes a first engine starting unit to curb PM emission by determining low torque necessity states, such as automatic driving or vehicle following modes, and uses specific engine starting methods like high-rotational-speed, ignition, compression-stroke, and intake-stroke starting, based on engine coolant temperature and stop time conditions to minimize PM emission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional engine starting methods are used in hybrid vehicles, then the engine can be started quickly, but the emission amount of particulate matter increases excessively
Solution Approach 1:
The patent applies dynamics by making the engine starting method adjustable based on vehicle operating conditions. The control unit dynamically selects between different starting methods (first engine starting unit for low torque necessity, second engine starting unit for high torque necessity) according to the vehicle's traveling state, thereby optimizing both emission control and torque response requirements
Solution Approach 2:
The patent changes the parameter of engine starting method selection based on operating conditions. By monitoring traveling torque requirements and automatically selecting appropriate starting methods, the system adjusts the engine starting parameters to balance emission reduction with the need for quick torque response when necessary
2Use of energy by moving object
If the engine is stopped and started frequently during traveling, then fuel economy improves, but particulate matter emissions increase during starting
Solution Approach 1:
The control unit implements feedback by continuously monitoring the vehicle's traveling state and torque requirements, then automatically adjusting the engine starting method selection. This closed-loop control ensures that emission-reducing starting methods are used when appropriate while maintaining the ability to quickly respond when torque is needed, thus supporting frequent engine stop-start operation for fuel economy without excessive emissions
3Device complexity
If a single engine starting method is used, then the system is simple, but it cannot simultaneously reduce emissions and ensure quick torque response
Solution Approach 1:
The patent segments the engine starting function into two distinct starting methods: a first engine starting unit for conditions with low torque necessity (prioritizing emission reduction) and a second engine starting unit for conditions with high torque necessity (prioritizing quick response). This segmentation allows each method to be optimized for its specific purpose while the control unit manages the selection between them
Data Source
AI summary
When a vehicle is in a traveling state having a low necessity to quickly increase required traveling torque, high-rotational-speed engine starting unit that reduces an emission amount of particulate matter emitted during engine starting starts the engine. Since quick torque response is not required when the vehicle is in the traveling state having the low necessity to quickly increase the required traveling torque, the high-rotational-speed engine starting unit starts the engine, so that increase of the emission amount of particulate matter emitted during engine starting can be curbed.