Vessel Azimuth Control with Adaptive Frequency-Response Gains
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Solution Overview
Problem
Existing vessel azimuth control systems fail to adequately identify vessel parameters and adjust control gains in response to dynamic changes in sailing conditions and disturbances, leading to unintended azimuth-control responses and inadequate identification during arbitrary steering patterns.
Innovation Solution
A vessel azimuth control apparatus and method that includes units for generating azimuth commands, detecting yaw angles and velocities, and adjusting control gains based on real-time frequency responses and vessel parameters, allowing for dynamic adjustments to maintain stable and responsive steering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the steering-angle offset and vessel parameters are regarded as fixed values for identification, then the identification process is simplified, but the vessel parameters cannot be adequately identified when the sailing azimuth changes or disturbances vary from moment to moment
Solution Approach 1:
The patent applies the dynamics principle by making the steering-angle offset and vessel parameters variable rather than fixed. The system continuously updates these parameters in real-time based on current sailing conditions and disturbance effects, allowing the identification process to adapt to changing azimuth and disturbance variations, thereby maintaining accurate parameter identification without excessive complexity
Solution Approach 2:
The patent implements feedback by using the identified vessel parameters and steering-angle offset to continuously monitor and adjust the azimuth control system. The system compares actual vessel response with expected response and uses this feedback to refine parameter identification, ensuring accurate parameter values are maintained even as sailing conditions change
2Measurement precision
If a step-like veering change is provided to the vessel azimuth command value for identification, then the identification of steering-angle offset and vessel parameters can be executed, but identification cannot be performed for arbitrary-pattern steering during normal sailing
Solution Approach 1:
The patent applies universality by designing an identification method that works across multiple steering patterns rather than requiring specific step-like commands. The system can perform parameter identification during arbitrary-pattern steering by continuously processing steering commands and vessel response data, making the identification process applicable to normal sailing operations regardless of steering pattern
Solution Approach 2:
The patent implements continuity by enabling ongoing parameter identification during normal sailing operations rather than requiring discrete identification maneuvers. The system continuously processes steering commands and vessel response data to update parameters in real-time, ensuring identification capability is maintained throughout arbitrary steering patterns without interruption
3Productivity
If the control gain is determined based on fixed vessel parameters, then the control gain calculation is straightforward, but the control gain becomes inadequate when vessel parameters change due to vessel speed, draft, or other factors
Solution Approach 1:
The patent applies dynamics by making the control gain variable rather than fixed. The system continuously updates control gain based on real-time vessel parameters that change with vessel speed, draft, and other factors. This dynamic adjustment ensures the control gain remains appropriate for current operating conditions, maintaining reliable azimuth control response without sacrificing calculation efficiency
Solution Approach 2:
The patent implements parameter changes by adjusting control gain in response to changes in vessel parameters such as speed and draft. The system monitors these parameter changes and automatically modifies control gain to maintain optimal control performance, ensuring reliability is preserved even as operating conditions vary
Data Source
AI summary
The vessel azimuth control apparatus hasan azimuth control unit that outputs a steering-angle command signal for making a vessel turn to an azimuth to which the vessel should travel, based on an azimuth command signal generated by an azimuth command generation unit, a yaw-angle signal, and a yaw-angular-velocity signal,a steering-angle control unit that controls a rudder based on the steering-angle command signal, anda control gain adjustment unit that has a calculation feasibility determination unit for determining feasibility of calculation of frequency responses, based on the yaw-angle signal and the yaw-angular-velocity signal, and that calculates respective frequency responses of the yaw-angle signal and the yaw-angular-velocity signal for the steering-angle signal, when the calculation feasibility determination unit determines that calculation of frequency response are feasible, and then adjusts a control gain of the azimuth control unit.