A DC motor controller, to put it simply, is any unit that can regulate the position, rpm, or torque of a DC-powered motor. DC motors can also be quickly reversed, unlike some AC motors, by actually swapping their leads such that the DC current flows in the opposite direction. These control systems for unmanned Underwater vehicles may vary and depends upon the requirement the speed, position, rpm or torque gets vary. The quantitative study exposed that the Superior estimation cannot be blamed for the increased efficiency. Estimation of coefficients was only on par with the best alternative methods; some coefficients were calculated more accurately, while others were estimated less accurately.

Reference:

https://www.mdpi.com/2076-3417/11/5/2144