Output feedback trackers for nonholonomic chained-form systems

Global trackers based on output feedback are constructed for nonholonomic systems in chained form. By combining a novel coordinate transformation with the cascade-design method, a reduced-order observer is given first. Then an output-feedback stabilizer is designed with the help of the cascade-design method again for the error-dynamics model under the introduced coordinate transformation. A new feature of the proposed method is that global K-exponential tracking is successfully obtained for nonholonomic systems in chained form without the popular condition of persistent excitation or not converging to zero on reference signals. Simulation results are provided to validate the effectiveness of the proposed method.