Dry Clutch Anti-Judder Control via Virtual Shaft Speed
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Solution Overview
Problem
Dry clutches in automated manual transmissions experience judder due to overheating, leading to reduced drivability and power transfer efficiency, which existing methods attempt to address by changing clutch materials but with limited success.
Innovation Solution
A dry clutch control method that generates a virtual target input shaft speed, detects vibration components, and applies anti-judder clutch control torque proportional to the amplitude of recognized vibrations, effectively offsetting clutch vibrations without material changes or additional vehicle weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If clutch material is changed to reduce judder, then drivability is improved, but manufacturing cost and complexity increase
Solution Approach 1:
The patent changes the operating parameters of the clutch system by dynamically adjusting clutch control torque based on detected vibration characteristics. Instead of changing material properties, the system modifies operational parameters (torque application timing and magnitude) to suppress judder while maintaining the original clutch material and structure.
Solution Approach 2:
The patent implements a feedback control mechanism where vibration components are detected from input shaft speed variations, analyzed to determine judder characteristics, and used to generate compensatory clutch control torque. This closed-loop feedback system continuously adjusts clutch operation to eliminate judder without requiring material changes.
2Ease of operation
If additional vibration suppression hardware is added, then judder is reduced, but vehicle weight and cost increase
Solution Approach 1:
The patent replaces potential mechanical vibration suppression hardware with a control system that uses existing sensors and actuators. By substituting physical vibration dampers with electronic control algorithms that manipulate clutch torque, the system achieves judder reduction without adding mechanical mass to the vehicle.
Solution Approach 2:
The clutch system serves its primary function while simultaneously suppressing its own vibrations through integrated control. The same clutch actuator that controls engagement also generates the compensatory torque needed for judder suppression, eliminating the need for separate vibration suppression components.
3Ease of operation
If clutch control torque is increased to suppress vibration, then judder is reduced, but power transfer efficiency decreases
Solution Approach 1:
The patent applies partial action by generating clutch control torque only in the specific direction and magnitude needed to counteract detected vibration components. Rather than continuously applying maximum torque to suppress all vibrations, the system calculates and applies only the necessary compensatory torque, minimizing energy loss while achieving judder suppression.
Solution Approach 2:
The patent makes the clutch control torque dynamic by continuously adjusting its magnitude and timing based on real-time vibration detection. The control torque varies with operating conditions and vibration characteristics, allowing optimal suppression efficiency that minimizes energy loss compared to static high-torque approaches.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method significantly reduces clutch judder, enhancing vehicle drivability without increasing costs or altering the vehicle's weight, by applying anti-judder torque only to the amplitude direction of the vibration component, thereby improving power transfer performance.
Implementation Method 1
a vibration recognizing step of detecting a vibration component based on a difference between an actually measured input shaft speed and the virtual target input shaft speed
Implementation Method 2
a control input step of applying as an anti judder control input a clutch control torque corresponding to only an amplitude in any one direction from a center of the amplitude of the vibration component recognized in the vibration recognizing step
Data Source
AI summary
A dry clutch control apparatus may include a vibration component extractor configured to generate a virtual target input shaft speed from a wheel speed and detect a vibration component based on a difference between an actually measured input shaft speed and the virtual target input shaft speed; and a feedback controller configured to feedback-apply as an anti judder control input a clutch control torque corresponding to only an amplitude in any one direction from a center of an amplitude of the vibration component recognized in the vibration component extractor.