带有输入时滞的动力定位船鲁棒滑模控制

Robust sliding mode control on the dynamic positioning vessel with control input time-delay

针对动力定位船定位作业时推进器、舵等执行机构的时滞问题,设计了一种根据时滞上界选取参数的鲁棒滑模控制器,以降低控制输入时滞对DP系统的影响.首先将多执行机构时滞简化为水平面三自由度的控制输入时滞,再将带有输入时滞的系统模型等效为状态时滞系统,然后针对未知有界干扰给出了带有时滞滑模项的鲁棒滑模控制律.在稳定性分析中,通过设计合适的Lyapunov-Krasovskii泛函,给出了系统稳定时控制增益的选取条件,证明了系统控制误差收敛于零.与传统的定位作业控制方法相比,该算法对时滞影响有一定的鲁棒性.仿真中利用PID和时滞鲁棒滑模控制算法,对比了船舶定位作业时的控制效果,说明了本文所提出算法的有效性.

To solve the time-delay problem of such actuators as thrusters and rudders in the positioning operation of dynamic positioning （DP） vessel, a kind of robust sliding mode controller has been designed for reducing negative effects of control input time-delay, with controller parameters chosen according to the upper bound of time-delay. First, the time-delay of the multi-actuator is simplified as a 3 degree-of-freedom control input time-delay, then a system model with input time-delay is equivalent to a state time-delay system, subsequently, for an unknown bounded environmental disturbance, the robust sliding mode control law with time-delay sliding mode item is given. In the stability analysis, by designing a proper Lyapunov-Krasovskii function, the selection condition for controlling gain in system stabilization is given, so to verify that the system control error is convergent to zero. In comparison with traditional DP control methods, the proposed algorithm has proper robustness for the time-delay influence. In the simulation case, PID and time-delay robust sliding mode controllers are utilized to compare the control effects in the positioning of vessel, which show the effectiveness of algorithm proposed in the paper.