A Globally Convergent Adaptive Velocity Observer for Nonholonomic Mobile Robots Affected by Unknown Disturbances

In this letter, we present a novel adaptive observer for nonholonomic differential-drive robots to simultaneously estimate the system’s angular and linear velocities, along with its external matched disturbances. The proposed method is based on the immersion and invariance technique and makes use of a dynamic scaling factor. The stability and convergence proof of the velocity and disturbance errors are performed using a strict Lyapunov function. We present a detailed simulation study to validate the performance of our approach.