QUATERNION-BASED ATTITUDE CONTROL OF HIGHLY MANEUVERABLE UNMANNED UNDERWATER VEHICLE

Traditionally, unmanned underwater vehicles are operated at low angles of inclination (pitch and roll). However, there are tasks that require high maneuverability and controllability of the underwater vehicle in the entire range of orientation angles. At the same time, traditional control systems use the Euler angles and have limitations associated with the degeneration of the kinematic equations at a picth angle of ± 90 °, the problem of the non-uniqueness of the Euler angles, and the deterioration of the system performance at large inclinations of the vehicle. Thus, the question of developing a synthesis method for a control system for highly maneuverable unmanned underwater vehicles arises. The paper provides a review and comparative analysis of existing approaches to attitude control, on the basis of which an approach using quaternions is chosen. The law of attitude control based on quaternions was approved during field tests on a hybrid unmanned underwater vehicle "Iznos", developed at Bauman Moscow State Technical University. The results obtained during the tests are given in the article. The quaternion-based approach has better performance in comparison with the traditional control system. In addition, control system based on quaternion approach has a simple structure and can be used to increase the maneuverability of unmanned underwater vehicles with average requirements for positioning accuracy.