An Approach to the Construction of High-Quality Position Force Control Systems for Autonomous Underwater Vehicles with a Multi-Link Manipulator

In this paper, a new approach is proposed to the construction of control systems for autonomous underwater vehicles equipped with multi-link manipulators for high-precision execution of various technological operations on underwater infrastructure objects, including those requiring force action on these objects, in fully automatic mode. The approach is based on creating a force effect on the work object using the thrusters of the underwater vehicle. In this case, all mutual influences from the manipulator moving in a viscous water space are taken into account, including nominal mutual influences between its links, the action of the added masses and moments of inertia of the liquid, as well as viscous friction. At the same time, the values of the added masses and moments of inertia of the liquid are proposed to be identified before the start of any technological operations using sliding mode observers and identification methods based on Kalman filters. Sliding mode observers allow us to estimate the values of generalized external torques acting in each actuator of the manipulator, as well as the values of rotational velocities and accelerations of their output shafts. The resulting minor displacements of the underwater vehicle during the execution of technological operations, due to errors in determining the force effect on the body of the vehicle from the operating manipulator, are compensated with the help of onboard stabilization systems of the underwater vehicle.