Intelligent Guidance and Control Laws for an Autonomous Underwater Vehicle

In this paper, intelligent guidance and control laws are developed for an autonomous underwater vehicle to engage underwater targets. The engagement of underwater targets is suffered from uncertainties of the complicated underwater environment, short detecting range of the sonar seeker, the low speed ratio between vehicle and target, and longtime operations but no accurate positioning technique. Uncertainties of underwater environment includes temperature-dependent sound propagation path, sound shadow zone, current flowing direction, current flowing noise and self-noise of the vehicle. The first object is to find the target. The second object is to track the target and to re-track the target after the target lost. Seven guidance laws are developed and switched by an intelligent selecting logic for target engaging. Six control modes for yawing and pitching channel are developed. Mode selections are dependent on the guidance laws selected. Those seven guidance laws and six control laws are well tested by digital simulation verifications of four scenarios. Simulation results give the proposed method can cope with the complicated underwater environment to engage the target. Key-Words: -Guidance and control laws, autonomous underwater vehicle, underwater target.