What is the principle behind Model control or Dead Reckoning mode in DP systems?

The principle behind Model control or Dead Reckoning mode in DP systems is that it maintains outputs despite system failures. In this mode, the DP system uses the information from its own model of the vessel's dynamics and environmental effects to predict its position and control its movement even when certain inputs or systems are compromised. This capability is crucial in ensuring that the vessel can maintain its predetermined position without immediate reliance on external sensors that may fail or become unreliable.

In the context of dynamic positioning, the system continuously calculates the expected position based on the last known data, taking into account factors like wind, wave, and current influences. By utilizing historical data and internal models, the DP system can make educated decisions about thrust and heading adjustments, thus providing a level of operational integrity even under less-than-ideal conditions.

The other choices do not accurately capture the fundamental characteristics of Model control or Dead Reckoning mode. For instance, relying solely on GPS data does not align with the principles of dead reckoning, which involves more than just satellite positioning. Likewise, continuous real-time feedback is not a defining feature of this mode but rather of more advanced control algorithms. Eliminating continuous monitoring is not a principle of this mode since monitoring remains essential for verification and system performance assessments.