Model reference control of deep submergence vehicles

The feasibility of employing a model reference controller synthesis technique to design a control system for a deen submergence vehicle (DSV) is investigated. The synthesis technique is based on Liapunov´s direct method and may be applied to nonlinear, time-varying, multivariable systems. The control system is based on a nonlinear control law. It forces the vehicle to behave like a linear time-invariant reference model. For motion in a plane, six model state variables are defined as the vehicle´s desired position coordinates and velocity components. An error vector is defined with components equal to the difference between these desired states and the vehicle´s actual position coordinates and velocity components. The control system causes the error vector to approach zero. Two types of control action are discussed: maneuvering from one specified position to another, and maintaining a fixed position under the influence of random currents. The two situations are simulated on a digital computer. Simulation results show that the vehicle behaves as desired in both cases.