Abstract: In the complicated traffic environment, the application of traditional adaptive cruise control is limited, because of the unpredictability of the leading vehicle in relative motion and driver’s intention. Hence, a multi-mode switching strategy for ACC is proposed. Based on the existing ACC hierarchical controller, a mode switching layer is added. Eight longitudinal driving conditions are defined and an optimal control mode should be determined according to the real driving conditions. Acceleration weighted average algorithm is adopted for the accuracy and output continuity during the switching. Six control modes including cruise mode, steady following mode, approaching mode, acceleration mode, hard braking mode and collision avoidance mode are designed. In order to improve the overall control quality, the corresponding upper controller is designed and variable parameters are set under different control objectives. Lastly, the vehicle test results verify the effectiveness and availability for the multi-mode ACC system.

Key words: Adaptive cruise control, Condition division, Mode switch, Vehicle test