Discontinuous finite-time tracking controller of nonholonomic mobile robots with unmeasurable velocity

In this paper, finite-time tracking problem of mobile robots in the presence of unmeasurable velocities and disturbances is studied. To accomplish this problem, the tracking error dynamic is transformed into two subsystems with disturbances, and the two subsystems are discussed respectively. First, a discontinuous controller is designed to realize finite-time tracking of mobile robots. Then, if the angular velocity is unmeasurable, a finite-time trajectory tracking controller based on a state observer is presented. When the trajectory is special, a finite-time controller is proposed to solve the tracking problem with unmeasurable angular and linear velocities. Finally we demonstrate the effectiveness of our proposed controllers with simulation.