Modeling, Simulation and Control of 3-DOF Redundant Fault Tolerant Robots by Means of Adaptive Inertia

Control systems that have the ability, in the one hand, to detect incipient failures in sensors and/or actuators and, in the other hand, to adapt quickly the control laws in order to preserve the specified performance in terms of production quality, safety, etc., are called fault-tolerant control systems (Blanke et al., 2001), (Blanke et al., 2006). This kind of systems have become increasingly important for manipulator robots, especially those performing in remote or dangerous zones, like outer space, underwater or nuclear environments. In this context, there is a growing need and interest in developing control systems that can operate in acceptable manners, even after the occurrence of failures, also being able to stop the process before irreparable damages arise (Bonivento et al., 2004). In this work, modeling, simulation and control of industrial fault tolerant robots by means of adaptive inertia is presented. This study, initially developed for robots with n Degrees Of Freedom (DOF), includes the calculation of adaptive inertia parameters; which is particularized for planar systems with two and three rotational joints. The modeling of these systems considers kinematic and dynamic aspects of robots, including the dynamics of actuators and position sensors that, by employing MatLab/Simulink software, permits the simulation and results displaying of dynamic behavior of such systems in front of actuator failures.