The maneuvering control of autonomous vessels has been under extensive investigations by academic and industrial communities since it is one of the primary steps towards enabling unmanned shipping. In this paper, a model predictive control (MPC) approach is presented for trajectory tracking control of vessels which takes into account the thrust allocation (TA) problem in the presence of rotatable thrusters. In this approach, the TA problem is formulated over a finite horizon and solved with regard to the power consumption, changes in the angle and speed of actuators, and the operating constraints. In the proposed control approach, several linearization techniques have been employed to enable the adoption of quadratic programming approaches for solving the MPC's and TA's optimization problems. The performance of the proposed approach is evaluated through several simulation experiments using a replica vessel model.

A novel signal control strategy for urban traffic networks, called ART-UTC (the abbreviated form of 'Adaptive Real-Time Urban Traffic Control') is introduced. We propose an efficient algorithm for ART-UTC to determine the green priority of different rights-of-way at each intersection. The proposed algorithm takes into account the queue length on each link, the waiting time of the first vehicle in the queue, and the incoming traffic flow to the link. We also propose a law to determine the green times of each traffic light based on the queue length on the link that is controlled by that traffic light. An advantage of ART-UTC is that due to the simple computations involved, it can be used for real-time urban traffic control. To evaluate ART-UTC, two different urban traffic networks are simulated within the urban traffic simulator SUMO. The performance of ART-UTC is compared to the performance of a fixed-time traffic controller based on Webster's formulas and a vehicle-actuated traffic controller. The results show that by using ART-UTC, the total travel time of the vehicles, the average queue length on the links in urban traffic networks, and the average waiting time of the first vehicles in the queues on the links of the traffic networks are reduced significantly in the majority of the cases compared with the fixed-time and the vehicle-actuated controllers.