Clutch Actuator Speed Control for Low-Noise AWD Engagement
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Solution Overview
Problem
Existing actuator systems in all-wheel-drive vehicles generate unwanted noise and vibration due to the mechanical operation of clutches, which can only be reduced by slowing down the actuator's delivery speed, leading to increased reaction time and discomfort for vehicle passengers.
Innovation Solution
A method for controlling the clutch actuator that adjusts speed based on the clutch's state, allowing for faster transitions between disengaged, synchronized, and engaged states, reducing noise and vibration by using different operating modes with varying speeds, and accounting for wear-dependent changes in the clutch's delivery path.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the actuator delivery speed is reduced to reduce noise generation, then noise and vibration are reduced, but the reaction time increases and clutch engagement/disengagement becomes slower
Solution Approach 1:
The actuator delivers force dynamically with varying amplitude over time, starting with high amplitude to quickly move the clutch piston to the kiss point, then reducing amplitude to minimize noise during final engagement. This dynamic delivery profile allows fast response time while controlling noise through adaptive force modulation.
Solution Approach 2:
The actuator uses periodic pulsing action to deliver force in controlled intervals. The force delivery is pulsed rather than continuous, with the first pulse providing high force for rapid positioning and subsequent pulses providing reduced force for noise-free final engagement, achieving both speed and comfort goals.
2Object-affected harmful factors
If the actuator moves the clutch slowly through the entire range to reduce noise, then noise is reduced, but time is lost in the region between mechanical end stop and kiss point
Solution Approach 1:
The clutch engagement process is segmented into distinct phases: a first phase from mechanical end stop to kiss point where high-speed movement is acceptable, and a second phase from kiss point to final engagement where noise reduction is prioritized. This segmentation allows optimized speed profiles for each phase, achieving overall time efficiency while controlling noise.
Solution Approach 2:
The actuator dynamically adjusts its delivery speed based on the clutch position and engagement phase. High speed is maintained during the first phase for rapid response, then speed is reduced in the second phase for noise-free operation, optimizing both time and noise characteristics through adaptive dynamic control.
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
Significantly reduces noise and vibration from the drivetrain while maintaining or slightly increasing the speed of clutch engagement and disengagement, thereby enhancing vehicle comfort without prolonging reaction times.
Implementation Method 1
The drive motor can be connected to the first disk by means of one or multiple gear pairings to transmit a rotational movement
Implementation Method 2
at least one spring for displacing the second disk along the axial direction
Implementation Method 3
a clutch which acts exclusively by means of friction, e.g. a multi-disk clutch
Data Source
AI summary
Controlling a clutch by means of an actuator, wherein at least one first shaft can be torque-transmittingly connected to a second shaft by means of the clutch, the clutch in one of at least three states, where in an disengaged first state, a torque cannot be transmitted, in a second state, a torque can be transmitted such that the speeds of the first shaft and the second shaft are synchronized in the second state, and in an engaged third state, a required torque can be transmitted; wherein, in various states and in an operating mode associated with the particular state, the actuator is adjusted at a different speed in order to adjust the clutch.