EV Transmission Shift Control to Suppress Direction-Change Shock
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Solution Overview
Problem
Electrified vehicles with transmissions that include forward and reverse gears experience significant shocks when switching between gear stages while traveling forward or backward, due to the motor's forward rotation driving the wheels in unintended directions.
Innovation Solution
An electronic control unit is implemented to control the motor's rotation direction, allowing reverse rotation when switching to reverse gear while traveling forward and forward rotation when switching to forward gear, thereby canceling inertial forces and reducing shocks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the gear stage is switched from forward gear to reverse gear while the vehicle is traveling forward, then the vehicle can travel backward, but a great shock is generated in the vehicle
Solution Approach 1:
The electronic control unit detects when the transmission is switched to reverse gear while the vehicle is traveling forward, and proactively controls the motor to perform reverse rotation before the shock occurs. This preliminary counter-action prevents the harmful shock by opposing the inertial force that would otherwise cause the shock during gear switching.
Solution Approach 2:
The system changes the rotation direction parameter of the motor from forward rotation to reverse rotation based on the detected gear stage and vehicle traveling state. By dynamically adjusting this parameter, the system ensures the motor rotates in the direction that prevents shock during transmission gear switching.
2Adaptability or versatility
If the gear stage is switched from reverse gear to forward gear while the vehicle is traveling backward, then the vehicle can travel forward, but a great shock is generated in the vehicle
Solution Approach 1:
The electronic control unit detects when the transmission is switched to forward gear while the vehicle is traveling backward, and proactively controls the motor to perform reverse rotation to counteract the inertial force. This preliminary counter-action prevents the harmful shock by opposing the force that would otherwise cause the shock during gear switching.
Solution Approach 2:
The system dynamically changes the motor's rotation direction parameter based on the detected gear stage and vehicle traveling state. When switching from reverse gear to forward gear during backward travel, the motor maintains reverse rotation to prevent shock, demonstrating parameter adaptation to operating conditions.
3Ease of operation
If the motor is controlled to perform forward rotation and the gear stage is switched while traveling, then the vehicle can change direction, but the drive wheels are driven in the unintended direction resulting in shock
Solution Approach 1:
The electronic control unit continuously monitors the transmission gear stage and vehicle traveling state, using this feedback information to determine the appropriate motor rotation direction. When the gear stage is switched during travel, the feedback mechanism triggers reverse rotation control to prevent the drive wheels from rotating in the unintended direction and causing shock.
Solution Approach 2:
The system changes the motor rotation direction parameter based on feedback from the transmission gear stage and vehicle state. By adapting this parameter dynamically, the system ensures the drive wheels rotate in the intended direction even during gear stage switching, preventing shock.
Data Source
AI summary
Provided is an electrified vehicle including a motor and a transmission, and a control method thereof. The electrified vehicle is caused to travel forward when forward gear is achieved and the electrified vehicle is caused to travel backward when reverse gear is achieved while the motor is performing forward rotation. When the transmission is switched to reverse gear while the electrified vehicle is traveling forward, or when the transmission is switched to forward gear while the electrified vehicle is traveling backward, fail-safe control to allow reverse rotation of the motor is executed, thereby suppressing a great shock from being generated in the vehicle.