Hybrid Powertrain Mode Transition Delay for Occupant Comfort
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Solution Overview
Problem
Hybrid vehicle power train mode changes initiated by the system, such as switching from zero-emission electric mode to emission mode with the internal combustion engine, are uncomfortable for occupants due to abrupt noise and vibrations, as they occur unexpectedly under constant driving conditions.
Innovation Solution
An operating method that introduces a delay or specific conditions for initiating the internal combustion engine startup, allowing the power train to remain in zero-emission mode until a predefined time, energy extraction, or distance is reached, and only switches to emission mode if conditions persist, with driver-initiated changes overriding system-initiated delays.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the system-initiated changeover from zero-emission mode to emission mode is implemented immediately when the state of charge reaches the threshold value, then the energy management strategy is executed as planned, but the vehicle occupants experience reduced comfort due to abrupt engine startup noises and vibrations
Solution Approach 1:
The control unit determines a starting command for the internal combustion engine in advance when the state of charge reaches the threshold value, but delays the actual execution of this command. This preliminary determination allows the system to prepare for the mode change while avoiding immediate engine startup, thereby maintaining energy management reliability while improving occupant comfort by postponing the harmful noise and vibration effects.
2Power
If the internal combustion engine is started to provide drive power, then the vehicle can overcome driving resistances effectively, but perceptible noises and vibrations are generated that reduce occupant comfort
Solution Approach 1:
The system determines the starting command in advance when needed based on energy management requirements, but executes it only after a delay period. During this delay, the vehicle continues operating in zero-emission mode if possible, or uses stored energy from the electric energy storage unit, thereby maintaining power availability while avoiding unnecessary abrupt engine startups that generate noise and vibration.
3Duration of action of moving object
If the state of charge threshold is set low to maximize zero-emission operation, then electric driving range is extended, but the internal combustion engine must start more frequently causing comfort issues
Solution Approach 1:
By determining the starting command in advance but delaying execution, the system can maintain a lower state of charge threshold for extended electric driving range while reducing the frequency of actual engine startups. The delay allows the vehicle to continue electric operation longer or use cached energy, thereby extending effective electric range while minimizing the harmful frequency of engine activations.
4Reliability
If the state of charge threshold is set high to ensure engine availability, then power reliability is improved, but the electric driving range is reduced and comfort deteriorates due to more frequent engine operation
Solution Approach 1:
The control unit determines the starting command in advance when the state of charge reaches the threshold, ensuring power reliability is maintained through proper energy management planning. However, by delaying the actual execution of this command, the system allows the vehicle to continue operating in zero-emission mode longer, thereby extending electric driving range and reducing the frequency of engine operations that harm comfort, while still ensuring the engine is available when truly needed.
Data Source
AI summary
An operating method for a power train of a hybrid vehicle having an internal combustion engine, an electric drive machine and a rechargeable electric energy storage unit configured to supply the electric drive machine with energy, includes controlling the power train in a zero emission mode in which the internal combustion engine is deactivated and in which the electric drive machine serves to drive the hybrid vehicle, and in an emission mode in which the internal combustion engine is operated in a fired operation. The method also includes determining, for a system initiated change of operating mode from the zero emission mode into the emission mode, a starting command for the internal combustion engine. The change of operating mode from the zero emission mode into the emission mode is blocked for one of a predefinable delay time, a predefinable quantity of energy extracted from the electric energy storage unit, or a predefinable travel distance.