Fault-tolerant Control of a Service Robot using a LPV Robust Unknown Input Observer

Abstract

In this paper, the control problem of a service robot under exogenous forces that might be exerted on the system is addressed, considering them as faults. Proposed approach is based on using a fault estimation scheme together with a Robust Unknown-Input Observer (RUIO) that allows to estimate the fault as well as the robot state, along with a state feedback control strategy. After the fault occurrence, from the fault estimation, a feedforward control action is added to the feedback control action to compensate the fault effect. To cope with the robot non-linearity, its model is transformed into a quasi-LPV model. Both the state-feedback and RUIO are designed using an LMI-based approach considering a gain-scheduling alike scheme, where global conditions have been considered. To illustrate the proposed fault-tolerant approach, a mobile service robot TIAGo, developed by PAL robotics, is used.