Dual Clutch Transmission Synchronization Control via Slip Acceleration Feedback
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Solution Overview
Problem
Dual-clutch transmissions (DCTs) face challenges in smooth synchronization control, leading to potential banging noises and requiring significant calibration efforts to achieve acceptable shift quality and speed, resulting in inefficiencies and performance issues.
Innovation Solution
A control system incorporating a pressure control solenoid, flow control solenoid, fork position sensor, slip sensing module, and sync control module that adjusts slip acceleration profiles to smoothly synchronize shift forks, using a closed-loop approach to minimize calibration efforts and ensure efficient power flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If traditional hydraulic control systems are used for shift fork synchronization, then the system structure is simple, but banging noises occur during shifting and significant calibration time is required
Solution Approach 1:
The patent implements a closed-loop feedback control system where the actual shift fork position is measured by a position sensor and fed back to the control unit. The control unit compares the actual position with the target position and adjusts the hydraulic pressure accordingly to minimize position error, ensuring smooth synchronization without banging noises while reducing calibration requirements.
Solution Approach 2:
The patent replaces traditional mechanical synchronization mechanisms with an electro-hydraulic control system. The control unit electronically calculates the required slip acceleration profile and converts it to hydraulic pressure commands, substituting mechanical linkages and synchronizers with electronic control and hydraulic actuation for smoother operation.
2Ease of manufacture
If traditional hydraulic control systems are used for shift fork synchronization, then the system structure is simple, but significant calibration time and effort are required to achieve acceptable shift quality
Solution Approach 1:
The closed-loop feedback control system automatically adapts to actual system conditions by continuously monitoring shift fork position and adjusting hydraulic pressure in real-time. This self-adjusting capability eliminates the need for extensive manual calibration, as the system automatically optimizes shift quality based on measured position data.
Solution Approach 2:
The control system performs self-calibration by using the position sensor feedback to automatically determine the relationship between hydraulic pressure and shift fork position. The system serves itself by automatically adapting to manufacturing tolerances and wear without requiring external calibration intervention, significantly reducing calibration time and effort.
3Device complexity
If manual transmission clutch disengagement is used for gear changes, then the mechanism is simple, but power delivery is interrupted causing efficiency loss
Solution Approach 1:
The patent pre-selects the target gear before the actual shift occurs by engaging the next gear's clutch in advance while the current gear is still engaged. This preliminary action allows the transmission to prepare for the shift without interrupting power flow, as the second clutch is already ready to take over immediately when the first clutch disengages.
Solution Approach 2:
The dual-clutch system maintains continuous power delivery by ensuring that while one clutch is disengaging, the other clutch is already engaged and ready. The overlap period between clutch operations is minimized through precise control, eliminating the on/off power delivery interruption characteristic of manual transmissions and maintaining continuous useful action.
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
The system enables smooth synchronization of shift forks in dual-clutch transmissions with reduced noise and calibration time, enhancing efficiency and performance by maintaining continuous power flow without interruptions.
Implementation Method 1
A pressure control solenoid and a flow control solenoid may be used to control operation of the clutches, shift forks and gear selectors
Implementation Method 2
A pressure control solenoid and a flow control solenoid having an input in fluid communication with the pressure control solenoid
Implementation Method 3
A piston adjusts a position of a shift fork and includes a first area in fluid communication with the pressure control solenoid and a second area in fluid communication with the flow control solenoid
Data Source
AI summary
A control system includes a pressure control solenoid and a flow control solenoid having an input in fluid communication with the pressure control solenoid. A piston adjusts a position of a shift fork and includes a first area in fluid communication with the pressure control solenoid and a second area in fluid communication with the flow control solenoid. A fork sensor senses a position of a shift fork. A slip sensing module estimates slip acceleration between an input shaft and a gear. A flow determining module generates a flow command for the flow control solenoid. A sync control module determines a slip acceleration profile including an estimated slip acceleration, adjusts the estimated slip acceleration based on the measured slip acceleration, and generates a pressure command for the pressure control solenoid based on the adjusted slip acceleration.