Vehicle Powertrain Clutch Control for Reverse Rotation Safety
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hybrid or electric vehicles with brushless electromotors face unpredictable behavior due to incorrect rotation direction, which can lead to safety risks, despite existing measures to mitigate this issue.
Innovation Solution
A powertrain system with a controllable clutch and feedback loop that disengages when the electromotor inadvertently rotates in the reverse direction, preventing propulsion and maintaining stability by correlating the clutch engagement with slip indicators and reference values, combined with monitoring the rotation direction to disable operation if it does not match the desired driving direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the electromotor is controlled to rotate in the correct direction to achieve desired driving direction, then the vehicle propulsion function is improved, but the risk of unpredictable behavior due to incorrect rotation direction cannot be completely eliminated
Solution Approach 1:
The patent applies preliminary anti-action by implementing a feedback control mechanism that preemptively counteracts the harmful effect of incorrect rotation direction. The system continuously monitors the actual rotation direction of the electromotor and compares it with the desired rotation direction. When a mismatch is detected, the controller immediately reverses the polarity of the drive signal to correct the rotation direction before it can cause unpredictable vehicle behavior. This proactive correction mechanism eliminates the harmful factor of incorrect rotation while maintaining reliable vehicle propulsion.
2Manufacturing precision
If a feedback loop with slip indicator is used to control clutch engagement, then the clutch control precision is improved, but the system complexity increases
Solution Approach 1:
The patent implements feedback control by introducing a slip indicator that continuously measures the slip between the clutch input and output shafts. The measured slip value is fed back to the controller, which adjusts the clutch engagement state accordingly. This feedback mechanism enables precise control of clutch engagement by maintaining the slip within a desired range, thereby improving clutch engagement precision while managing system complexity through a straightforward feedback loop architecture.
Data Source
Figure 1~1A
Figure 2~3
Figure 4
AI summary
A powertrain for a vehicle is disclosed that includes an electromagnetic driving unit (10) and a transmission module (20) comprising a controllable clutch (21) the powertrain further includes a control system to control the electromagnetic driving unit and to control the clutch. The controller has a safety operational mode wherein it controls an engagement of the controllable clutch with a feedback loop in which a desired extent of engagement is positively correlated to a difference between an extent of slip as indicated by the slip indicator and a positive reference value for said extent of slip, wherein the slip indicator indicates the extent of slip with a sign that is the product of the sign of the difference between the rotational speed of the input shaft and a rotational speed of the output shaft and a desired driving torque sign.