Maritime drift control system

A maritime vessel with a maritime drift control system and at least one propulsion device, the maritime drift control system having:

• a vessel movement detection Unit which detects actual vessel speed and direction of the vessel;
• a drift error generator is connected to the vessel movement detection unit and receives the actual vessel speed and direction therefrom;
• the drift error generator generates drift error signals depending on a predetermined speed limit and the actual vessel speed;
• a vessel movement control unit having a drift controller which is connected to the drift error generator and receives the drift error signals transmitted by the drift error generator, the drift controller is configured to compute propulsion command signals and transmit the propulsion command signals to the at least one propulsion device;
• the at least one vessel propulsion device is connected to the drift controller and receives the propulsion command signals transmitted therefrom, the at least one vessel propulsion device being controlled based on the propulsion command signals to adjust a speed of the vessel to a target value;
• the drift error generator generates a drift error signal equal to zero;
• if the actual vessel speed is lower than approximately 50% of the predetermined speed limit;
• the drift error generator generates a drift error signal in a high error range, if the actual vessel speed is greater than approximately 150% of the predetermined speed limit;
• the drift error generator generates a drift error signal in a low error range that is between zero and the high error range, if the actual vessel speed is in a range of between 50% and 150% of the predetermined speed limit;
• the drift error generator is configured to calculate an integral of the drift error signals;
• the drift error generator is configured, when the actual vessel speed is below the predetermined speed limit, to apply a decaying function to reduce said integral;
• and
• the at least one propulsion device being controlled based on the propulsion command signals received from the drift controller to adjust the speed of the vessel to the target value.