Optimization and convergence of manipulation tasks in the priority-level control framework

Redundant robots, in particular mobile manipulators, are becoming increasingly important over the years. Thanks to their flexibility, in fact, they are capable of properly interacting with the surrounding environment, exploiting the high number of possessed degrees of freedom. On the other hand, for the latter reason, the resolution of the kinematics problem becomes rather complex (in particular the inverse kinematics equations), therefore many different studies have been dedicated to this research field. One of these control strategies, called priority-level control, is characterized by the great advantage of establishing a priority based sorting of the different tasks the robot has to perform. In this way, this latter is allowed to execute several complex functions concurrently, each of which does not perturb the accomplishment of the tasks having a higher priority. This technique constitutes the core of this paper also because of its possibility of deactivating a task whenever the conditions allow to do so, mitigating any possible discontinuity in the robot behavior too. This project, strictly based on the priority-level control strategy, deals with three different possible improvements of the related framework. At first, a finite-time control technique will be described, then the implementation of a manipulability task and of a conflict avoidance approach will be presented. Consequently, a series of simulations will be carried out to prove the correctness of the aforementioned theory.