Practical Predefined-time Sliding Mode Control for Uncertain Marine Natural Gas Engine

It is a significant and challenging task to realize the speed control of marine natural gas engines with uncertainty and external disturbances. In this paper, a new speed control strategy based on practical predefined-time stability and nonlinear sliding surface was proposed for marine natural gas engine. Firstly, the nonlinear uncertain engine mathematical model including complex intake dynamics and torque generation dynamics is established. Then, a nonlinear sliding manifold is designed using predefined-time stability theory to improve the tracking performance. In order to reduce response time of engine speed, a novel practical predefined-time reaching law is utilized for controller design. Further, strict theoretical analysis proves the stability of the closed loop system. Finally, in order to further prove the effectiveness and advantages of proposed approach, it was compared with traditional PID and non-singular terminal sliding mode (NTSM) control in simulation.