Marine Drive Steering Control with Dynamic Angle Limits
Solution Overview
Problem
Existing marine steering systems face challenges in adapting the permitted drive angle range to prevent collisions between closely mounted marine drives, especially under high-speed conditions or when one drive is deactivated, leading to unresponsive steering and potential hazards.
Innovation Solution
The system adjusts the maximum drive angle and permitted drive angle range by controlling a resistance device to prevent steering wheel rotation past an end stop position and shifts the steering map to ensure the drive angle stays within the permitted range, using a central control module to manage multiple marine drives independently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the maximum drive angle is increased to improve steering responsiveness, then steering control is enhanced, but the risk of collision between closely mounted marine drives increases
Solution Approach 1:
The system dynamically adjusts the maximum drive angle based on operational conditions. When drives are closely mounted or one drive is deactivated, the system reduces the maximum drive angle to prevent collisions. This dynamic parameter adjustment allows the steering system to maintain high responsiveness when safe to do so while automatically limiting the drive angle to prevent collisions when necessary, thus resolving the contradiction between steering responsiveness and collision risk.
Solution Approach 2:
The system changes the parameter of maximum drive angle adaptively based on the operational state of marine drives. By monitoring whether drives are closely mounted or deactivated, the system modifies the permitted drive angle range, shifting the steering map accordingly. This parameter change enables the system to optimize steering responsiveness under normal conditions while preventing collisions under restricted conditions.
2Reliability
If the permitted drive angle range is narrowed to prevent collisions between marine drives, then collision safety is improved, but steering responsiveness deteriorates
Solution Approach 1:
The system makes the permitted drive angle range dynamic rather than fixed. It continuously monitors the operational status of marine drives and adjusts the maximum drive angle accordingly. When drives are closely mounted or one is deactivated, the system narrows the permitted range to ensure collision safety. When conditions allow, it expands the range to restore steering responsiveness, thus dynamically balancing safety and responsiveness.
Solution Approach 2:
The system changes the parameter of the permitted drive angle range based on real-time operational conditions. By shifting the steering map and adjusting the maximum drive angle, the system optimizes the balance between collision safety and steering responsiveness, allowing full responsiveness when safe and limiting it only when necessary to prevent collisions.
3Ease of operation
If the steering system allows full rotation of the steering wheel, then steering freedom is maximized, but unresponsive steering occurs when drives are deactivated
Solution Approach 1:
The system implements feedback by monitoring the operational status of marine drives and using this information to adjust the permitted drive angle range. When a drive is deactivated, the system receives feedback about this condition and automatically narrows the permitted range, shifting the steering map to maintain responsive steering within the safe limits. This feedback mechanism ensures steering freedom is maintained within safe operational boundaries.
Solution Approach 2:
The system changes the parameter of the permitted drive angle range based on feedback about drive operational status. By dynamically adjusting the maximum drive angle and shifting the steering map, the system maintains steering freedom within safe limits while preventing unresponsive steering behavior that would occur if full rotation were allowed when drives are deactivated.
Data Source
AI summary
A method of operating a steering system for a marine vessel includes controlling a resistance device to apply a resistance force against rotation of the steering wheel in a first rotational direction past an end stop position, controlling a steering actuator associated with a marine drive based on a steering map and such that a drive angle of the marine drive stays within a permitted drive angle range, and determining that the current wheel position has passed the end stop position and then adjusting control of the steering actuator to account for the current wheel position being past the end stop position.