EV Motor Torque Control for Virtual Gear Shift Sensation
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Solution Overview
Problem
Electric vehicles without multi-speed transmissions lack the driving sensation and excitement typically experienced in vehicles with multi-speed transmissions, leading to a sense of boredom for drivers seeking a more engaging driving experience.
Innovation Solution
A control method that generates a virtual sensation of gear shifting by determining a basic torque command and virtual gear shift intervention torque based on vehicle driving information, using a virtual gear shift model to simulate the experience of multi-speed gear shifting, allowing the motor torque to be adjusted accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a multi-speed transmission is installed in an electric vehicle, then the driving sensation and excitement are improved, but the device complexity and structural complexity increase
Solution Approach 1:
The patent creates a virtual copy of the gear shifting experience by generating simulated torque fluctuations that mimic the sensation of multi-speed gear shifting. The controller produces a virtual gear shift intervention torque that replicates the mechanical sensations of traditional transmissions without requiring actual transmission components, thereby providing the desired driving sensation while avoiding the complexity of installing a multi-speed transmission system
Solution Approach 2:
The patent replaces the mechanical transmission system with an electronic control system that generates virtual gear shifting sensations through torque modulation. Instead of using physical gears and transmission mechanisms, the system uses the motor controller to create torque variations that simulate gear shifting effects, substituting a complex mechanical system with a simpler electronic control approach
2Adaptability or versatility
If a multi-speed transmission is installed in an electric vehicle, then the gear shifting sensation is improved, but the smooth operability is deteriorated
Solution Approach 1:
The patent implements periodic torque interventions that simulate the rhythmic sensation of gear shifting. The controller generates virtual gear shift intervention torque in periodic cycles that mimic the timing and pattern of actual gear shifts, providing the driver with the sensation of gear changing while maintaining the underlying smooth operation of the single-speed transmission system
3Device complexity
If a reduction gear with fixed gear ratio is used in an electric vehicle, then the device complexity is reduced, but the driving fun and excitement are deteriorated
Solution Approach 1:
The patent introduces dynamic torque modulation to a static single-speed transmission system. The controller dynamically adjusts the motor torque by adding virtual gear shift intervention torque based on driving conditions, vehicle speed, and acceleration patterns. This dynamic control creates varying torque characteristics that simulate the effects of multiple gear ratios, bringing excitement and variability to the otherwise fixed-ratio transmission system
Data Source
AI summary
A control method of an electric vehicle is proposed. The control method includes generating and realizing a virtual sensation of gear shifting the same as that of a vehicle equipped with a multi-speed transmission, in the electric vehicle without a multi-speed transmission. In particular, virtual gear shift intervention torque and limit torque for each virtual gear shift stage are determined from input variables through a virtual gear shift model by inputting vehicle driving information collected from a vehicle during operation. Then the determined virtual shift intervention torque, the determined limit torque for each virtual shift stage, and motor torque command are applied to operate a motor, thereby realizing the virtual sensation of multi-speed gear shifting.