Boat Shift Actuator Control for Neutral Engagement
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Solution Overview
Problem
Conventional remote control systems for boats require a large force to shift out of forward or reverse into neutral, often resulting in unsuccessful shifts due to mechanical limitations and high reaction forces, leading to actuator motor shutdown during electrically controlled shifting.
Innovation Solution
A remote control operation unit with a shift actuator that achieves a target position beyond the reference position of the shift actuator where the dog clutch is in the middle of the neutral range, allowing reliable shifting from forward or reverse to neutral, even under high shift-out loads, by controlling the shift actuator to maintain a constant gain and adjust based on shift speed and electric current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a conventional shift actuator is used to disengage the dog clutch from forward or reverse gear, then the actuator must generate large force to overcome the engagement reaction force, but this results in insufficient clutch disengagement due to mechanical play and torsion, leading to shift-out failure
Solution Approach 1:
The control means performs preliminary action by detecting the shift lever position and calculating the appropriate actuator operation amount before actual shifting occurs. The control means pre-determines the operation amount based on the shift lever position within the shift range, ensuring the actuator is ready to apply the correct force to disengage the dog clutch from the engaged gear, thereby overcoming the reaction force and mechanical play issues.
2Use of energy by moving object
If the shift actuator is controlled with a simple gain of 0 when not in neutral position, then the actuator motor stops, but this results in unsuccessful shift-out when large reaction forces are present
Solution Approach 1:
The control means applies dynamics by dynamically adjusting the actuator operation amount based on the shift lever position. Instead of a static gain of 0, the control means continuously monitors the shift lever position within the shift range and adjusts the actuator operation amount accordingly, enabling the actuator to apply variable force as needed to overcome reaction forces and ensure successful shift-out while managing energy consumption.
3Ease of operation
If mechanical play and torsion in the shift switching device are present, then the actuator operation is imprecise, but this causes insufficient dog clutch movement even with actuator operation, leading to shift-out failure
Solution Approach 1:
The control means implements feedback by continuously monitoring the shift lever position and using this information to adjust the actuator operation amount. The control means detects the shift lever position within the shift range and uses this feedback to calculate the appropriate operation amount, compensating for mechanical play and torsion in the shift switching device, thereby ensuring precise dog clutch movement and successful shift-out.
Data Source
AI summary
A remote control operation unit can have a remote control shift lever through which a boat operator can remotely select between forward, neutral, and reverse drive modes. A boat propulsion unit can have a shift switching device for shifting and a shift actuator for operating the shift switching device. A controller can be configured to control the operation of the shift actuator in response to the operation amount of the remote control shift lever. The controller can also be configured to control the shift actuator such that the shift actuator achieves a first target position that is a position beyond a reference position of the shift actuator where a dog clutch is in the middle of a neutral range, when the remote control shift lever has been shifted from either a forward position or a reverse position to a neutral position.