Question on dynamic positioning

I am aware of several joystick control systems. The new pod drives from Volvo and Mercury as well as some retrofits for boats with thrusters. And, these often offer "stay on station" buttons that work with gps to remain an approximate position. Inguess this is called DP1. I went to the Ft. Lauderdale boat show and asked several vendors about the logic behind the technology. They did not seem to understand the question. So, here is taking another try.

Is the joy stick control (retrofit) just a way to engage the thrusters OR does the system have the logic to vary the thrusters with the prevailing conditions. So, on a calm day, moving the joystick to port may fully engage the bow and stern thrusters. But, keeping the boat moving parallel in a blow or strong current may require unequal application of the thrusters. How much logic is built into the dp1 systems available on pleasure boats?

 

The system gets a signal from the GPS to calculate the position. When the position changes it will engage, shifters, steering, throttles to compensate. The pods will rotate to be out of alignment (compared to normal running) to help with the maneuvering.

 

DPS-1 is a classification of the systems dynamic positioning capability. See the following ABS guide.

https://www.eagle.org/eagleExternal...itory/Rules&Guides/Current/191_DPSguide/Guide

How much logic? Depends on who wrote the code. Most DP systems use PID controllers (https://en.wikipedia.org/wiki/PID_controller) so usually there is a bias depending on the force balance.