An adaptive switched robust H∞ control for CACC system considering road adhesion coefficient and communication failure

This paper proposes an adaptive switched robust H infinity control framework for cooperative adaptive cruise control systems, integrating tire-road adhesion coefficient (TRAC) estimation to enhance platooning safety and efficiency under varying road conditions. The method employs an extended Kalman Filter combined with the Pacejka Magic Formula tire model, enabling accurate TRAC estimation during low-acceleration coasting scenarios and complex steering conditions. A novel friction-adaptive variable time headway strategy is introduced, dynamically adjusting inter-vehicle spacing through a piecewise function of TRAC. The robust H-infinity controller addresses vehicle-to-vehicle communication delays, packet loss, and complex vehicle interactions while maintaining string stability. Experimental results demonstrate that the proposed framework reduces spacing errors by 34% compared to conventional methods under low adhesion conditions, and ensures safe platoon operation with spacing adaptation to abrupt TRAC changes from 0.8 to 0.65.