Controlled movement of portable underwater system (PUS)

Abstract

Purpose of research . The article contains mathematic simulation and research of movement of a portable underwater robot designed to monitor pollution of hydrosphere objects. Modern methods of environmental monitoring suggest the presence of stationary sites. The task of mobile controlled monitoring remains unresolved currently. One of the ways to solve this problem is the transition to control systems that provide a given movement of the water system both on the surface and under water. Therefore, the purpose of this article is to study and set the basic laws and algorithms based on mathematical models that describe the controlled movement of portable underwater systems. Methods . When developing the motion control algorithm for PUS, a mathematical model was used to determine the spati-temporal location of PUS with a variable thrust vector. The basic mathematical expressions that determine the movement of PUS in a predetermined path are obtained. Particular attention is paid to that part of the algorithm that ensures the movement of PUS in a predetermined path in underwater mode if there is no contact with the global navigation system, taking into accounts the underwater GPS and the distance to the bottom and obstacles. As the main criterion of quality of control system we have used the deviation of the actual position of PUS from the position datum. Results . To select the direction of movement when monitoring water, a method of planning the trajectory, built on piecewise linear sections, has been developed that allows probing the space of water in such a way as to ensure maximum efficiency of the monitoring process with a minimum number of sampling points. For this, each new segment of the trajectory and sampling points are planned taking into account information on the concentration of pollutants at the previous stage, as well as the coastline and the depth of water. Conclusion The article discusses the method for monitoring water bodies using a portable unmanned underwater system. The kinematic and dynamic models of the PUS movement are developed. It is proposed a method of planning a trajectory of motion based on piecewise linear segments. We have developed an algorithm of controlling the autonomous movement of the underwater vehicle.