Unmanned Surface Vessel (USV) is gaining great popularity in various fields including marine environmental monitoring and coastal waters protection and it is becoming world-focused marine equipment.
USV can reduce direct human intervention and perform safe operations in hazardous environments such as marine exploration, personnel rescue, environmental monitoring and survey, etc.
When the USV is sailing, it will deviate from the given course due to the disturbances of wave, current, wind and other marine environment.
Although several technical proposals have been proposed to solve this problem, ship control still remains a very challenging problem.
Ship course is mostly controlled by the conventional PID control law. Conventional controllers are still regarded as a good choice for an auto-steering system when they have typical SISOs, but not suitable for a complex and strong nonlinear MIMO system like USV. Indeed, this method is easy and simple, but its parameters are set by manual experience and control is possible in the limited range, which leads to low adaptability.
Choe Kum Song, a section head at the Faculty of Shipbuilding and Ocean Engineering, has obtained USV’s hydrodynamic parameters from its sailing test data and built a linear mathematical model of 3-DOF for USV planar motion. On this basis, he has proposed a course control algorithm for USV based on fuzzy PD and compared it with the conventional PID law.
The simulation results show that the designed fuzzy PD law is more effective than the conventional PID law.
© 2021 KumChaek University of Technology