A SCHEME FOR RECONFIGURABILITY OF MOBILE ROBOTS

Abstract

Mobile robots have a great deal of applications in industry, mining, space, forest, . agriculture, demining, military, and underwater areas. They often work in dynamic and unpredictable environments. During a mission, its ability to respond robustly and reliably to unexpected environmental changes and mechanical failure is highly desired. The reconfigurability of mobile robots is an important issue in the industrial applications also, as a faulty vehicle may hamper the continuous flow of material in an industry. To develop fault adaptive control of a mobile robot, a well developed and validated model of the system and its environment is required. This thesis presents a model-based approach for reconfiguration of an autonomous vehicle with sixteen degrees of freedom. The dynamic modeling of autonomous vehicle is performed using bond graph. Dynamic modeling of mobile robot includes the modeling of dynamics of body, wheel and suspension system. Then a proportional-derivative controller has been developed for its positional and directional control. This bond graph model is used for generating the Analytical Redundancy Relations (ARRs) which are used to generate residuals and to perform structural fault isolation. Once the fault list is updated in the equipment availability database, an automaton selects the next best option to reconfigure the system such that the given control objectives are achieved. The developed methodology is validated by considering nine different fault scenarios. The faults are assumed to be as actuator faults.