Wet Clutch Control via Feedforward Learning for Fast Coupling
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Solution Overview
Problem
Existing methods for controlling wet clutches and brakes in vehicles are conservative and unable to adapt quickly to changing environmental conditions such as temperature and wear, leading to inefficient coupling times and potential safety issues.
Innovation Solution
A control method using a feedforward closed-loop controller with an iterative learning control (ILC) system that adjusts the control signal in real-time based on reference and target profiles, allowing for faster and more precise coupling while compensating for wear and temperature changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If high filling pressure is applied during the filling phase to achieve fast coupling, then coupling speed is improved, but torque peaks and uncomfortable coupling behavior occur
Solution Approach 1:
The patent applies dynamic pressure control by continuously adapting the filling pressure during the filling phase based on actual system response. Instead of using fixed high pressure, the control system monitors coupling progress and adjusts pressure in real-time, allowing fast coupling while preventing torque peaks through dynamic adaptation to changing system conditions.
Solution Approach 2:
The patent implements feedback control by monitoring the coupling process and using this information to adjust the filling pressure. The control system receives feedback on coupling status and modifies the pressure profile accordingly, ensuring that high pressure is applied only when safe and necessary, thereby achieving fast coupling without harmful torque peaks.
2Reliability
If conservative control methods are used to ensure safe coupling, then coupling safety is improved, but coupling time increases
Solution Approach 1:
The patent applies preliminary action by pre-defining safe pressure profiles and coupling sequences that have been optimized for safety. The control system executes these pre-planned sequences while adapting to actual conditions, allowing fast coupling without compromising safety because the preliminary planning already accounts for safe operating parameters.
Solution Approach 2:
The patent changes control parameters dynamically during the coupling process. Instead of maintaining constant conservative pressure, the system adjusts pressure parameters based on coupling phase and system state, enabling shorter coupling times while maintaining safety through parameter adaptation rather than fixed conservative values.
3Device complexity
If fixed control profiles are used for coupling, then control simplicity is improved, but adaptability to changing conditions deteriorates
Solution Approach 1:
The patent transforms fixed control profiles into dynamic adaptive profiles. The control system starts with a base profile but continuously adapts it based on temperature, wear, and actual coupling behavior. This dynamic approach maintains relative simplicity while significantly improving adaptability to changing environmental and operational conditions.
Solution Approach 2:
The control system performs self-adjustment by automatically modifying control parameters based on sensor feedback and observed system behavior. It self-calibrates to temperature changes and wear patterns without requiring external intervention or complex manual reconfiguration, maintaining simplicity while achieving high adaptability through autonomous parameter optimization.
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 approach enables shorter coupling times without increasing the risk of uncomfortable coupling behavior, improving control accuracy and adaptability to changing conditions, thus enhancing safety and efficiency.
Implementation Method 1
a filling space between the piston and the clutch chamber is filled with suitable oil or other liquid, so that the piston is displaced by the oil from a disengaged state towards the clutch elements (filling phase)
Implementation Method 2
Wet clutches transmit torque from a first shaft to a second shaft by means of friction
Data Source
Figure 1~3
Figure 4~7
Figure 8~9
AI summary
Apparatus (control device) and a method for controlling a torque transmitting device such as a brake, wet clutch, dry clutch (10) during a filling and slip phase is provided, e.g. for coupling a first shaft (12) to a second shaft (14) via the wet clutch (10). A reference profile (52) for a control variable is provided, wherein the chronological progress of said control variable influences the position of a piston (22) for actuating clutch elements (16, 18). Each clutch element (16, 18) is connected to the first shaft (12) or the second shaft (14), with respect to a cylinder (20) of the wet clutch (10), and the control variable is determined during each coupling and a valve (38) for applying a pressure source to the piston (22) is operated, wherein the valve (38) is controlled during each coupling by means of a feed forward closed loop control (54) such that the control variable follows the reference profile (52). Due to the increased control quality by considering non-linear effects by means of the reference profile (52) for the feed forward closed loop control (54) at every coupling through learning, the coupling time can be shortened without increasing the risk of an uncomfortable coupling behavior.