http://ktisis.cut.ac.cy/handle/10488/4913 Search the Channel search http://ktisis.cut.ac.cy/simple-search http://ktisis.cut.ac.cy/handle/10488/7842 Title: Nonholonomic stabilization with collision avoidance for mobile robots<br/><br/>Authors: Loizou, Savvas; Tanner, Herbert G.; Kyriakopoulos, Kostas J.<br/><br/>Abstract: This paper presents a motion planner and nonholonomic controller for a mobile robot, with global collision avoidance and convergence properties. An appropriately designed (dipolar) potential field is combined with discontinuous state feedback. A new class of Lyapunov functions is introduced and used for nonholonomic navigation. The obstacle avoidance and global asymptotic stability properties are verified through simulations. http://ktisis.cut.ac.cy/handle/10488/7825 Title: Control of the multi agent micro-robotic platform MiCRoN<br/><br/>Authors: Loizou, Savvas; Vartholomeos, Panagiotis; Thiel, Michael<br/><br/>Abstract: This paper presents the theoretical framework for the centralized control architecture of the multi agent microrobotic platform MiCRoN. The entire control system architecture integrates sensory modules, modeling modules, and control modules. The latter are composed by (i) a high level simulation and autonomous execution unit that is capable for on-line multi-robot navigation with collision avoidance, (ii) a trajectory tracking unit for manipulation purposes, and (iii) a low level position controller that performs position control exploiting machine learning algorithms. The high level controllers take into account behaviors specific to the micro-scale. The performance of the layered control system is evaluated through simulations and preliminary hardware experiments on a micro-robotic platform. The application domain of the MiCRoN platform is cell manipulation, and 3-D assembly for micro-fabrication. http://ktisis.cut.ac.cy/handle/10488/7817 Title: Closed loop navigation for multiple holonomic vehicles<br/><br/>Authors: Loizou, Savvas; Kyriakopoulos, Kostas J.<br/><br/>Abstract: We extend the navigation function methodology, established for single robot navigation, to the case of multiple robots. Appropriate expression of the robot potential functions guarantees global convergence. The derived closed form navigation function provides a robust navigation scheme, suitable for real time implementation. The collision avoidance and global convergence properties are verified through simulations. http://ktisis.cut.ac.cy/handle/10488/7814 Title: Motion tasks for robot manipulators on embedded 2-D manifolds<br/><br/>Authors: Loizou, Savvas; Papageorgiou, Xanthi; Kyriakopoulos, Kostas J.<br/><br/>Abstract: In this paper we present a methodology to drive the end effector of a robotic manipulator across the surface of an object in the workspace. Three typical tasks are considered, namely stabilization of the end effector over the object's surface, motion planning and eventually trajectory tracking of the end effector across the object's surface. The proposed controllers utilize navigation functions and are based on the belt zone vector fields concept. The derived dynamic controllers are realized using an integrator backstepping methodology. The derived feedback based controllers guarantee global convergence and collision avoidance. The closed form solution provides fast feedback rendering the methodology particularly suitable for implementation on real time systems. The properties of the proposed methodology are verified through non-trivial computer simulations.