4륜 공기 현가 장치의 제어 및 고장 안전 로직

This paper proposes height control and failsafe logic for a closed loop four wheel air suspension control system. Based on understanding and researching existing air suspension system, we develop new control algorithm and method. We analyze the air suspension system and classify six modes according to vehicle height. The system inputs consist of vehicle conditions and driver's commands, such as the vehicle speed, the vehicle heights, the steering angle, a mode select switch input and etc. The logic determines target height from input signals and controls actuators such as a compressor, two reversing valves, and four air spring valves. First, the main logic determines target vehicle height and detects the faults of the various parts through the target mode decision logic and the fault detection logic. On results of this logic, it is performed for the target height correction logic, the failsafe logic and determining actuators commands. Finally the vehicle engages to target height. The control logic is developed by model based design method and constructed the simulation environment using Matlab/Simulink and CarSim. To verify suggested control and failsafe logic, simulations are conducted under the reasonable condition.