Real-time identification of vehicle body motion-modes based on motion-mode energy method

Abstract Vehicle body dominant motion-modes, including bounce, roll, and pitch, are highly related to vehicle ride comfort and handling performance, while are generally coupled. Real-time identification of dominant motion-mode with the three motion-modes benefits control on active suspensions. The conventional (7-DOF vehicle model based) motion-mode energy method (MEM) for motion-mode identification needs 14 vehicular states and 4 road information, blocking its real vehicle application. This study simplifies the MEM on a 3-DOF body model to identify the dominant motion-mode real-timely. This method requires less and easily accessible inputs compared with conventional methods in real time. This consequently enables practical application of instant dominant motion-mode identification. The proposed method gives a new way to decouple suspension deflection into each body dominant motion-mode, and only uses easily accessible suspension deflection, vehicle body angle, angle rate and vertical motion of a vehicle. Moreover, the relative error of mode energy ratio between the developed method and the traditional method is under 5% in simulation, which indicates high accuracy of the developed method. The real-time ability and reliability of the developed method are experimentally proved under different driving conditions. The experiment results confirm that the proposed method is effective regarding identification of the dominant vehicle motion-mode on typical driving scenarios. This method helps design of vehicle dynamic control strategy, and therefore improves active suspension performance.