Evaluation of Multi-Vehicular Underwater Transportation Systems under Disturbances, Sensor Noise and Limited Sensor Readings

Underwater transportation using multiple Autonomous Underwater Vehicles (AUVs) could be useful for safely and securely transporting a military payload as well as precisely transporting and installing underwater installations. It is significant to investigate different transportation systems in the underwater environment and priorities these systems under different operational conditions. These systems are named the Rigid Connection Transportation System (RCTS), Dynamic Connection transportation System (DCTS) and Leader-Follower Formation Control Transportation System (LFFCTS). An estimator was designed using Kalman Filter to estimate the full state of the systems under the constraints of disturbances, sensor noise and limitation in sensor readings. The PID based controllers were applied to track the desired trajectory under the mentioned constraints. RCTS was found to have a higher motion precision than DCTS. The motion accuracy of the leader vehicle of LFFCTS was higher but lower for the follower vehicle compared to RCTS and DCTS. The accuracy of swing angles of the flexible joint links of DCTS was lower even at using very high controller gains. This made the overall motion accuracy of DCTS the lowest. In terms of power consumption, RCTS and LFFCTS consumed around the same amount of power. On the other hand, the power consumption of DCTS was the highest. Though RCTS is overall better, the importance of DCTS and LFFCTS cannot be denied in certain situations.