Secure Dual-Channel Joint Defense Strategy for Steer-by-Wire Systems Against DoS Attacks

For vehicle steer-by-wire (SbW) systems, intelligent connected vehicle technology has improved their performance while making them vulnerable to denial-of-service (DoS) attacks. Since the sampling and control signals share the same CAN bus, both sensor-to-controller and controller-to-actuator channels are prone to simultaneous signal interruptions under DoS attacks, significantly reducing the accuracy of steering angle tracking. This article innovatively proposes a secure dual-channel joint defense strategy that enhances tracking accuracy under DoS attacks. For secure observation, the estimation error system is established to consider uncertainties caused by external disturbances and measurement noise. By introducing constraints that characterize the convergence speed and bounds of estimation errors, it ensures high accuracy of state observation in uncertain SbW systems under DoS attacks. For robust control, the designed tube-based model predictive control introduces an auxiliary control input to constrain future states that may be affected by system disturbances caused by potential DoS attacks, to a robust positive invariant set, suppressing the jumping phenomenon in switching control caused by uncertainty, leading to prediction performance degradation and achieving smooth actuator outputs. Hardware-in-the-loop experiment results demonstrate that the proposed strategy ensures stability of the SbW system under DoS attacks and effectively improves the transient response performance and tracking accuracy for the reference steering angle.