SYNTHESIS OF THE UNDERWATER CARGO LIFTING COMPLEX CONTROL SYSTEM

Abstract

A carrier vessel is used to transport an underwater cargo. The given vessel is equipped with a unit for
lifting underwater cargoes designed to capture it, lift it, secure it on the vessel and transport it to the base
point. The given unit includes the following components: the descent module, the lifting mechanism, the locking
mechanism, the damping mechanism and the control system. The paper presents the findings of the mathematical
model development of the main components for the unit to make a crucial contribution to obtaining
reliable results – an underwater cargo, an asynchronous motor, a cable suspension and a compensation
mechanism. The underwater cargo is described based on the theorems about the change in the amount of
motion and kinetic moment of the mechanical system. In the equations of linear and angular displacement of
a cargo, there is a mass of liquid in it. The cable suspension model takes into account its deformation in motion
while operating. The model of an asynchronous motor with a short-circuited rotor is obtained from a
generalized circuit. A vector control method is provided, the rotor flow coupling vector is taken as the base
vector. The compensation mechanism model is based on an adiabatic process in a macroscopic system,
where there is no heat released into. For the control system synthesis, the cargo is represented by a transfer
function in the form of an aperiodic link of the second order. There is a three-loop PID controller synthesized
with feedback in position, speed and current. Equations are obtained for calculating the generalized dynamic
characteristics of a closed second-order system, and the controller parameters are calculated. The findings
carried out on mathematical models of the system help us to obtain initial information about the linear and
angular displacement of the descent module in steady state, the movement of points of external and internal
suspensions, the magnitude of the force on the cables, the torque and speed developed by electric motors of
winches. Modeling of descent, stabilization and ascent modes made it possible to adjust the parameters of the
equipment and achieve satisfactory results of the complex's operation.