A Method for Synthesis of Position-Force Control Systems for Electric Drives of Multi-Link Manipulators Mounted on Autonomous Underwater Vehicles. Part 2

In the first part of the article, the authors proposed a comprehensive method for solving the problem of synthesizing combined position-force control systems (CS) for electric drives (ED) of multi-link underwater manipulators (MUM) mounted on autonomous underwater vehicles (AUV) operating in mode of landing on a seabed or on work sites, followed by rigid fixation of these AUV using special devices. To do this, the following subtasks were successively solved. First, the synthesis of self-adjusting regulators was performed, ensuring the stabilization of variable dynamic parameters of the ED at a given nominal level. Secondly, a synthesis of observers with a variable structure has been performed, which allows using only measurements from angle sensors of the ED output shafts when creating MUM CS. And thirdly, the synthesis of position-force regulators has been performed, which, by minimizing the selected quadratic cost function, make it possible to ensure accurate working out of the specified movements of the ED output shafts while maintaining the required moments on them. The second part of the paper describes the operation of the MUM position-force CS, which makes it possible to create the required force effects with its work tool on the surface of work objects during its movement along the trajectory. Moreover, this CS ensures the successful performance of force operations in the presence of continuously changing and previously unknown parameters of the interaction of the MUM links with a viscous medium, including the velocity of the liquid flow, viscous friction and the MUM links added masses and moments of inertia. The operability and effectiveness of the synthesized position-force control systems is confirmed by the results of computer modeling, the analysis of which made it possible to determine the conditions under which it is necessary to accurately take into account the various features of the impact of a viscous medium on the MUM links when performing complex technological operations.