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• SYNTHESIS OF THE UNDERWATER CARGO LIFTING COMPLEX CONTROL SYSTEM

  P.P. Chernus, Pavel P. Chernus, А.А. Yakovlev, R.V. Sakhabudinov, А. S. Golosiy

  2024-05-28

  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.

• SYNTHESIS OF A DIGITAL REGULATOR OF A HYDRAULIC SYSTEM FOR STABILIZING AN UNDERWATER OBJECT

  P.P. Chernus, Pavel P. Chernus , А.A. Yakovlev, R.V. Sakhabudinov, А.S. Golosiy

  2023-04-10

  Abstract ▼

  The article presents the results of the development and synthesis of a hydraulic system for
  stabilizing an underwater object. For completeness and accuracy of mathematical modeling in the
  hydraulic system, the forces of dry friction between the piston and the walls of the hydraulic cylinder,
  the forces of dry friction between the rod and the hydraulic cylinder, which together determine
  the total dry friction force in the active hydraulic cylinder, the total dry friction force in the
  passive hydraulic cylinder, and the acceleration of movement, are taken into account. Also taken
  into account is the reduced mass of the system of blocks and chain hoist, the mass of the moving
  parts of the active and passive hydraulic cylinders. After calculating the mass and dynamic characteristics
  of the hydraulic stabilization system, mathematical modeling of the developed system
  was carried out. In the process of developing and synthesizing the system, the features and typical
  non-linearities of the hydraulic and pneumatic parts included in the system were taken into account,
  such as the flow characteristic of a spool-type hydraulic valve, low leakage and compression
  costs in the working cavities of the active hydraulic cylinder. When designing, the adiabatic
  nature of the process in the pneumohydraulic displacer was adopted, since the reaction and
  movement of the hydraulic stabilization system occurs quite quickly, which means that the heat
  exchange with the environment will be negligible. In the process of synthesizing the mathematical
  model of the system, the nonlinearity of the rope elasticity coefficient is taken into account. A study
  of the stability of the mathematical model of the stabilization system was carried out and a synthesis
  of the control system for the hydraulic part of the system was carried out using a fairly common
  PID controller. The PID controller parameters were calculated using a standard calculation
  method. Since the result of the operation of the stabilization system with such a synthesis of the
  control system strongly depended on the perturbation signal, it was decided to increase the invariance
  of the system with respect to the input signal by introducing a combined control. Such an
  improvement of the system turned out to be sufficient to improve the quality of the mathematical
  model of the hydraulic stabilization system. A digital redesign of the controller was carried out,
  the features of the operation of analog-to-digital transducers of sensors were taken into account.
  The simulation results showed the operability of such a control system.