Flatness-Based Active Disturbance Rejection Control For a Wheeled Mobile Robot Subject To Slips and External Environmental Disturbances

This work suggests flatness-based Active Disturbance Rejection Control (ADRC) to deal with the problem of trajectory tracking for Wheeled Mobile Robot (WMR). Based on the differential flatness theory, the nonlinear WMR system is transformed into two integral- chains, which makes the creation of a state feedback controller easier. In order to improve the WMR tracking, slip and external environmental disturbance must be considered in the controller design. Therefore, an Extended State Observer (ESO) is created to estimate the obtained linearized system state and the extended state known as lumped uncertainties. The latter represent the total effects of slip and the external environmental disturbances to WMR. After that, according to the ESO results, a complementary element is added to the state feedback controller to compensate the effects of lumped disturbances. Simulation results are introduced to demonstrate the advantages of combining ADRC with flatness control.