Marine Vessel Heading Control With Slow-Speed Impulse Steering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing marine vessel auto-heading systems face challenges in maintaining accurate heading at slow speeds due to differential vessel handling characteristics, leading to wandering and unpredictable yaw rate responses, especially when operating in no-wake zones or on larger vessels.
Innovation Solution
Implementing a control module that uses separate logic for non-planing speeds, employing impulse steering inputs and accumulated offset calculations to quickly correct heading errors, rather than traditional PID feedback control, which reduces oscillations and maintains desired headings more effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional PID feedback control is used for auto-heading, then the system is simple to implement, but heading accuracy deteriorates at slow speeds due to wandering and unpredictable yaw rate responses
Solution Approach 1:
The control system is segmented into two distinct modes: a PID feedback control mode for normal operation and an impulse control mode for slow-speed conditions. The system divides the operating range and applies different control strategies based on vessel speed, thereby achieving high heading accuracy at slow speeds without sacrificing simplicity in normal operating conditions.
Solution Approach 2:
The control system dynamically switches between PID feedback control and impulse control based on vessel speed conditions. This dynamic adaptation allows the system to optimize performance for each operating regime, maintaining simplicity when PID control suffices while achieving precision when impulse control is required.
2Measurement precision
If impulse steering inputs are used to correct heading errors at slow speeds, then heading accuracy improves, but the control logic becomes more complex
Solution Approach 1:
The control system applies different control qualities to different operating conditions: PID feedback control for normal speeds and impulse control for slow speeds. This local differentiation ensures that the more complex impulse control logic is only activated when necessary, minimizing overall system complexity while maximizing heading accuracy where needed.
Solution Approach 2:
The system changes the control parameter based on vessel speed, transitioning from continuous PID feedback to discrete impulse steering inputs. This parameter change allows the system to achieve superior heading error correction at slow speeds while keeping the control logic manageable through clear conditional thresholds.
3Ease of operation
If PID feedback control is used, then the control system is easy to operate, but yaw rate stability deteriorates at slow speeds
Solution Approach 1:
The control system dynamically adapts its operation mode based on vessel speed, maintaining ease of operation through automatic mode selection. The operator simply engages auto-heading mode, and the system automatically applies impulse control when appropriate, preserving yaw rate stability without requiring operator intervention or complex manual adjustments.
Solution Approach 2:
The control system performs self-service by automatically detecting slow-speed conditions and switching to impulse control mode without operator input. This self-adjusting capability maintains yaw rate stability while keeping the interface simple, as the system serves itself by selecting the appropriate control strategy based on operating conditions.
Data Source
AI summary
A method is disclosed for controlling heading of a marine vessel having a steerable component coupled thereto, the steerable component being rotatable to affect a direction of movement of the vessel. The method is carried out by a control module and includes accepting a command to initiate a control mode in which the vessel's heading is to be maintained at a desired heading. The method includes receiving a current heading of the vessel and determining a heading error between the current heading and the desired heading. The method also includes determining if the vessel is on-plane or off-plane. In response to the vessel being off-plane, the method includes controlling the steerable component to rotate by at least a predetermined correction amount away from a starting position in a direction that will cause the vessel to rotate to reduce the heading error, and subsequently to rotate back toward the starting position.