Simultaneous optimization of control gains and reference filter coefficients for trajectory tracking control

TL;DR

The paper tackles simultaneous optimization of dynamic-positioning control gains and reference-filter coefficients under actuator and rate saturation. It adopts a backstepping DPS controller and models saturation penalties in the optimization objective, solving for 18 parameters with CMA-ES and tuning 6 reference-filter parameters alongside 12 gain parameters. The optimized gains reduce saturation exceedances while the jointly designed reference filter yields appropriate target trajectories across scenarios. Simulation results demonstrate improved tracking performance and feasible reference generation under wind disturbances, highlighting practical impact for ship automation.

Abstract

Research on vessel automation and autonomy is currently being conducted by various countries and institutions. Safe and accurate ship control algorithms are crucial to realize automated operation. Actuator drive constraints of a target ship may jeopardize the stability of the control law and require complex theory. In this study, we include a penalty term to the control law gain optimization stage of dynamic positioning systems to account for the amounts by which the actuator input value and its rate of change exceed the constraint. The parameters for generating a suitable reference path for the control law are identified simultaneously with the control gains. The simulation results show that the proposed method can realize control parameters and a reference design with excellent tracking performance while determining the cost of the controller design by considering the effects of both the actuators and rate saturation.

Figures (5)

• Figure 1: Example of unstable controlling of a ship due to actuator saturation
• Figure 2: The coordinate systems in this study
• Figure 3: Example of 4 corner testing
• Figure 4: The results of the trajectory for the test scenario.
• Figure 5: Time variation of each parameter related to the control law in the test scenario. The parameters $u_1,u_2,$ and $u_3$ represent $\delta_{\mathrm{P}},\delta_{\mathrm{S}},$ and $n_\mathrm{B}$, respectively. The light blue areas indicate the driving range. The colors of the lines in the graph are the same as in the legend of Fig. \ref{['fig:Result of Trajectory']}