EV Shift Control Using Torque-Gated Skip Shifting
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Solution Overview
Problem
Conventional electric vehicles experience instability and reduced operability due to abrupt changes in drive force when shifting modes or torque maps, leading to wheel slip and compromised behavior, especially during consecutive shifting operations.
Innovation Solution
A control system for electric vehicles that allows skip shifting of operating ranges based on target torque values and threshold settings, preventing abrupt torque changes by selectively enabling or disabling consecutive shifts based on predetermined criteria, such as torque values and rates relative to vehicle speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If consecutive shifting operations are allowed to provide manual shifting experience, then driver operability is improved, but vehicle stability deteriorates due to abrupt torque changes
Solution Approach 1:
The control device predicts the target torque value before executing the shifting operation. By calculating the anticipated torque change in advance, the system can determine whether the shift will cause excessive torque variation, and prevent such shifts before they occur, thereby maintaining vehicle stability while preserving manual shifting functionality.
Solution Approach 2:
The system continuously monitors actual torque values and compares them with predicted values. When the absolute difference exceeds a predetermined threshold, the control device prevents further consecutive shifting operations. This feedback mechanism dynamically adjusts shifting availability based on real-time torque conditions, balancing operability and stability.
2Adaptability or versatility
If multiple torque maps are provided for different operating ranges, then torque characteristics adaptability is improved, but system complexity increases
Solution Approach 1:
Multiple torque maps are stored in the storage device, each corresponding to different operating ranges. The control device selectively accesses appropriate torque maps based on current operating conditions, allowing the system to provide diverse torque characteristics without requiring separate control systems for each range. This multi-functionality approach maintains adaptability while managing complexity through unified control logic.
Data Source
AI summary
A control system for an electric vehicle for allowing a driver to virtually enjoy a manual shifting operation as performed in the conventional vehicles having transmissions without reducing stability and operability of the electric vehicle. A controller is configured to set a required drive torque in accordance with a selected operating range, and to selectively allow an execution of a skip shifting of the operating range to the range further than two ranges from the current operating range, based on the required drive torque to be set in the operating range selected by operating a shifting device consecutively.