EV Gear Shifting Control for 10-30 RPM Engagement Matching
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Solution Overview
Problem
Current electric vehicle transmissions have a limited success rate of gear shifting due to inconsistent rotational speed differences between engagement components, leading to gear shifting failures and the need for repeated attempts.
Innovation Solution
A gear shifting method that adjusts the rotational speed difference between the input-side and output-side engagement components to a precise range of 10-30 rpm, ensuring accurate engagement by issuing an engagement command only after completing the speed adjustment process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional gear shifting method is used, then the transmission can shift gears, but the success rate of gear shifting is limited due to inconsistent rotational speed differences between engagement components
Solution Approach 1:
The patent applies parameter changes by precisely controlling the rotational speed difference parameter between engagement components. The control unit adjusts the rotational speed of the output engagement component to maintain a specific speed difference range (10-30 rpm) relative to the input engagement component, transforming the gear shifting process from a粗放 approach to a precisely controlled parameter-based approach, thereby significantly improving the success rate of gear engagement.
2Productivity
If rotational speed difference is not controlled precisely, then the gear shifting process is simpler, but gear shifting failures occur and repeated attempts are needed
Solution Approach 1:
The patent implements feedback control by continuously monitoring the rotational speeds of both input and output engagement components through sensors. The control unit receives real-time speed information, calculates the actual speed difference, and dynamically adjusts the output component's rotational speed to maintain the target difference range. This closed-loop feedback mechanism ensures accurate speed matching while automating the complex control process, improving gear shifting efficiency without requiring manual intervention.
3Reliability
If the engagement command is issued before speed adjustment is complete, then the gear shifting process is faster, but the rotational speed difference is inconsistent leading to engagement failure
Solution Approach 1:
The patent applies preliminary action by completing the speed adjustment process before issuing the engagement command. The control unit first adjusts the rotational speed of the output engagement component to achieve the desired speed difference range (10-30 rpm), and only after this preliminary speed matching is confirmed does it proceed to activate the engagement command. This sequential approach ensures that engagement components are properly synchronized before contact, significantly improving engagement reliability while minimizing unnecessary repeated attempts.
Data Source
AI summary
A gear shifting method is for use in electric vehicles. The gear shifting method includes a speed adjustment process in which a speed adjustment request is issued to adjust the rotational speed of the drive motor of the electric vehicle, ensuring that the absolute rotational speed difference between the output-side engagement component and the input-side engagement component remains within the range of 10 rpm to 30 rpm when the input-side engagement component and the output-side engagement component of the transmission, driven by the drive motor, are disengaged. The method also includes an engagement process in which an engagement command is issued after the completion of the speed adjustment process, so as to engage the input-side engagement component with the output-side engagement component for gear engagement.