Optimal control methods are increasingly used in automatic control systems, especially in automotive suspension system. However, the optimal control algorithm only achieves the highest efficiency in suspension control system when the required number of sensors is sufficient, corresponding to the number of states in the system. The arrangement of sufficient number of sensors depends on the capacity, economic conditions and responsiveness of the sensor. The Kalman observer is designed to reliably estimate the required parameters in the control where the number of sensors is limited. The article focuses on analyzing the theory of building a quarter-car model, developing and determining the optimal control matrix, the Kalman observer design method. The findings of the article reveal the effectiveness of automotive body vibration suppression and the required force for control corresponding to different control algorithms, under the influence of square pulse road surface, when using the different sensor types, thereby providing a choice of sensor type and the location on the semi-active ¼ suspension.
