Clutchless Multi-Gear Shift Control Using Motor Generator Torque
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Solution Overview
Problem
Existing drive systems with multi-speed transmissions face challenges in achieving smooth shifting processes that enhance driving comfort and reduce pollutant emissions, particularly during combustion engine-driven gear changes, as they often require friction clutches that increase complexity and emissions.
Innovation Solution
The method involves controlling the first electric motor to generate increasing load torque before gear disengagement and decreasing load torque after gear engagement, allowing the internal combustion engine to operate continuously and reducing torque fluctuations, thereby eliminating the need for friction clutches and minimizing emissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If friction clutches are used to enable power transmission during shifting, then shifting comfort is improved, but device complexity and cost increase
Solution Approach 1:
The patent extracts and removes the friction clutch component from the transmission system by utilizing the generator mode of the first electric motor to relieve torque during shifting operations, thereby achieving clutchless shifting and reducing device complexity while maintaining shifting comfort
Solution Approach 2:
The patent replaces the mechanical friction clutch system with an electrical control system where the first electric motor operates in generator mode to manage torque during shifting, substituting mechanical friction-based torque management with electrical torque control
2Ease of operation
If friction clutches are used for shifting operations, then shifting smoothness is improved, but pollutant emissions increase
Solution Approach 1:
The patent removes the friction clutch component that causes emissions during engagement/disengagement operations, replacing its function with electrical torque management through the first electric motor in generator mode, thereby eliminating the source of pollutant emissions while maintaining shifting smoothness
3Object-generated harmful factors
If the internal combustion engine is shut down during shifting, then emissions are reduced, but vehicle acceleration is interrupted
Solution Approach 1:
The patent maintains continuous operation of the internal combustion engine during shifting operations by using the first electric motor in generator mode to manage torque transitions, allowing the engine to remain running and provide continuous power while still reducing emissions through optimized torque management during the shifting process
4Reliability
If the first electric motor is operated in generator mode to relieve torque, then mechanical switching means are protected, but energy is consumed
Solution Approach 1:
The patent converts the potentially harmful torque that would damage mechanical switching means during shifting into a beneficial control mechanism by operating the first electric motor in generator mode, where the generated electrical energy can be recovered and stored, thereby protecting the switching means while minimizing net energy consumption through energy recovery
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 approach provides a 'virtual double clutch' experience with constant vehicle acceleration and reduced emissions, as the internal combustion engine can be operated efficiently without shutting down, and the drive system can be implemented cost-effectively without friction clutches, enhancing both acoustic and haptic comfort.
Implementation Method 1
the first electric motor EM-I being operated at least briefly in generator mode in order to disengage a gear of the multi-speed transmission 110
Data Source
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AI summary
The invention relates to a drive system (100), to a control device (CTR), and to a method (10) for controlling a mechanical shifting operation in the drive system (100), wherein the drive system has at least one first multi-gear transmission (110), which has a first input shaft (111) and a first mechanical shifting means (115), wherein torques coming from the first input shaft (111) are transmitted to an output shaft (130) of the drive system (100), and wherein the torques are produced by an internal combustion engine (VKM) and/or at least one first electric motor (EM-I). For the purpose of disengaging a gear of the multi-gear transmission (110), the first electric motor (EM-I) is operatively connected to the internal combustion engine (VKM) and operated in a generator operating mode (steps 12, 13) at least at times (T12, T13) during the shifting operation, whereby the internal combustion engine (VKM) is loaded and the first mechanical shifting means (115) is unloaded. The mechanical shifting means (115), which can be, for example, a shifting sleeve, a shifting coupling, or an interlocking coupling, is thus free of load or free of torsion and can be easily disconnected/opened. During the entire shifting operation (T11-T17), the internal combustion engine (VKM) can be continuously actively operated, in particular fired (steps 11-17), but at least during a time span (T12-T16) of the shifting operation in which the first electric motor (EM-I) is operated in the generator operating mode. The driver is thereby given the acoustic and haptic impression of a drive having a "virtual dual clutch".