Objective Aiming at the problems of unknown ship model parameters and external disturbance and servo constraints, this paper proposes a method for the data-driven online identification of ship parameters and iterative analytical calculation of the optimal control quantity of track tracking control.
Method A three degrees of freedom dynamics equation of a double propeller ship is constructed, and the extended state observer-multiple innovation recursive least squares interactive algorithm is designed by collecting the motion data of the ship. By approximating the identified ship motion model to a time-invariant linear model in the sampling period, the ship trajectory tracking problem can be transformed into a linear quadratic optimization control problem with constraints and disturbances. The weighted matrix and penalty function are introduced to construct the quadratic performance index including trajectory error, external disturbance, and control constraint inequality. The precise integration method is then used to obtain the analytical solution of the matrix Riccati differential equation and the iterative calculation formula of the finite time state regulator.
Results Th online identification of the ship motion model parameters and estimation of unknown disturbances are achieved, and a trajectory tracking control algorithm with "no need to worry after startup" is designed, reducing the strict requirements of parameter identification and control algorithms for experimental design.
Conclusion Using MATLAB to carry out numerical simulation and analyze the influence of weight matrix \boldsymbolQ,\boldsymbolR and S on trajectory tracking accuracy, the results verify the effectiveness of the parameter identification and control algorithm.
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