A Path Correction Module for two-wheeled service robots under actuator faults

Autonomous wheeled robots are receiving significant attention in various applications, including security monitoring of remote or hazardous locations and moving goods in warehouses with the minimum human intervention. At some unknown time, the operation of these robots may be affected due to some actuator fault, which causes the robot to partially lose the ability to navigate and to achieve its goals. In this work, a model-based Fault Detection, Isolation and Path Correction Module (FDI-PC) is presented, suitable for non-holonomic two-wheeled service robots. The first step of the FDI-PC is to determine whether an actuator fault has occurred, based on the measured states and the control inputs. The second step is to determine the type of fault that has occurred, i.e. whether the fault affects the left or right wheel, and to identify its magnitude using adaptive estimation. The third step is to modify the control input using a path-correction algorithm so that the robot maintains its ability to reach its goal. Simulation results on a realistic model of a two-wheeled service robot demonstrate the effectiveness of the FDI-PC Module.