Marine Vessel Trajectory Tracking Control via Nested Loop Linearization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing marine surface vessel motion control systems are overly complex and have limited effectiveness due to the underactuation of vessels with two degrees of freedom actuators for three degrees of freedom motions, making it challenging to achieve precise trajectory tracking.
Innovation Solution
A multi-nested loop trajectory linearization guidance control system is introduced, comprising a nominal open-loop controller and a closed-loop tracking error controller. The nominal controller generates nominal control signals based on a desired trajectory without requiring motion variable sensing, while the tracking error controller uses sensed errors to produce corrective control signals, ensuring exponential stability and effective error elimination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If independent longitudinal motion control and lateral-directional control are used, then the control system structure is simple, but the trajectory tracking precision is poor due to underactuation
Solution Approach 1:
The control system is segmented into two independent controllers: a longitudinal motion controller for surge control and a lateral-directional controller for sway-yaw control. This segmentation allows each controller to focus on specific degrees of freedom, simplifying the overall control architecture while addressing the underactuation challenge through coordinated control of the available actuators.
Solution Approach 2:
The control system employs dynamic coupling between the longitudinal and lateral-directional controllers, where the controllers exchange information and coordinate their actions in real-time. This dynamic interaction enables the system to achieve better trajectory tracking performance by utilizing the coupled dynamics of the vessel rather than treating each degree of freedom independently.
2Manufacturing precision
If model-based control techniques are used, then the control accuracy is improved, but the control algorithm complexity increases
Solution Approach 1:
The control algorithm utilizes changes in vessel parameters such as mass, inertia, and hydrodynamic coefficients to adapt the control inputs. By incorporating these parameter variations into the model-based control framework, the system achieves accurate trajectory tracking while maintaining a manageable level of algorithmic complexity through systematic parameter identification and compensation.
3Adaptability or versatility
If data-driven control techniques are used, then the adaptability to uncertainties is improved, but the computational requirements and system complexity increase
Solution Approach 1:
The control system incorporates feedback mechanisms where the actual vessel state is continuously measured and compared with the desired trajectory. The tracking errors are fed back to the controllers, which adjust the control inputs in real-time to compensate for uncertainties and disturbances. This feedback-based approach provides adaptability without requiring complex data-driven algorithms, maintaining computational efficiency while handling system uncertainties.
Data Source
AI summary
Systems, methods, and computer program products for controlling a marine surface vessel. Nominal position and nominal heading signals are received from a trajectory planner, and nominal force and nominal moment signals generated based thereon. A velocity tracking error signal is generated based on the sensed velocity signal, and a yaw rate tracking error signal is generated based on the sensed yaw rate signal. A force tracking error control signal is generated based on the velocity tracking error signal, and a moment tracking error control signal is generated based on the yaw rate tracking error signal. A force command signal is generated by summing the nominal force and force tracking error control signals, and a moment command signal is generated by summing the nominal moment and moment tracking error control signals. The force and moment command signals are used to control one or more actuators of the marine surface vessel.