Ship Propulsion Clutch Slip Control via Ramp Function
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Solution Overview
Problem
Existing ship propulsion systems face high mechanical stresses and abrupt clutch slip adjustments due to direct setpoint value variations, leading to challenging maneuvering and safety issues during direction changes.
Innovation Solution
A control apparatus using an electronic control unit that applies a ramp function characteristic to gradually reduce clutch slip during engagement, splitting cruise commands for engine speed and sense-of-rotation signals, and incorporating a speed limiting unit to maintain suitable engine speed for trolling operations, ensuring gentle clutch engagement and reduced mechanical stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the adjustment value for the adjustable clutch is varied directly in response to the setpoint value, then the clutch slip can be adjusted quickly, but this leads to abrupt slip variation and high mechanical stresses on the drive train
Solution Approach 1:
The control system performs preliminary action by gradually varying the clutch adjustment value according to a predetermined time profile before reaching the final setpoint. This ramp-function-based approach prepares the drive train for the slip change, reducing abrupt mechanical stresses while still achieving the desired clutch slip adjustment within a defined engagement period.
2Stress or pressure
If the clutch engagement process is made gentle to reduce mechanical stress, then the drive train is protected, but the engagement time increases which may reduce maneuvering responsiveness
Solution Approach 1:
The control system applies dynamics by using a time-varying ramp function for clutch adjustment that can be adapted to different operating conditions. The engagement profile is dynamically optimized to balance gentle stress reduction with acceptable engagement time, allowing the system to protect the drive train while maintaining reasonable maneuvering responsiveness.
3Stress or pressure
If the clutch engages with minimal slip to reduce mechanical stress, then the drive train is protected, but the full power of the propulsion system cannot be utilized during engagement
Solution Approach 1:
The control system applies periodic action by structuring the clutch engagement in phases: an initial phase with minimal slip to protect the drive train, followed by a transition phase where power is gradually increased. This phased approach ensures drive train protection during the critical engagement moment while still allowing full power utilization to be achieved shortly after engagement completes.
Data Source
AI summary
A control unit and a method for influencing the speed of an engine and the slip of a downstream clutch of a transmission of a ship's propulsion system via an electronic control unit in response to a manual control-signal generator to select the sense of rotation and the driving speed, wherein, as the clutch is engaged to initiate forward or reverse driving, a slip determination unit of the electronic control unit influences the slip of the clutch in response to a ramp function characteristic to reduce the clutch's slip during an engagement period.