Active Shimmy Control Method for Driverless Electric Vehicle Considering Unknown Sensor Measurement Error via Sampled-Data Output Feedback

Compared with traditional vehicles, driverless electric vehicles equipped with electric wheels are more likely to generate the front wheel shimmy phenomenon, which affects driving comfort and safety. It is necessary to study an active control approach to alleviate or even eliminate the shimmy phenomenon. The current active shimmy control methods do not consider the sensor measurement error. However, the sensor measurement error worsens the effect of an active shimmy control method in practice. For addressing this issue, this paper proposed a novel active shimmy control method considering unknown sensor measurement error via sampled-data output feedback. Firstly, a four-degree-of-freedom (4-DOF) shimmy model of the front electric wheel is built. The dynamic functions of the model are obtained via the Lagrange theorem. Based on the dynamic functions, a shimmy control system with unknown sensor measurement error and nonlinearities is proposed. Then a sampled-data output feedback control (SOFC) method is proposed for the shimmy control system. By selecting an appropriate domination gain, the designed controller can globally asymptotically stabilize the system even in the presence of unknown measurement error. Finally, the 4-DOF shimmy model and the SOFC method for the shimmy system are verified via simulation. The simulation results show that the SOFC method can address the sensor measurement error issue.