Sensor and actuator deception attacks often manipulate states and control commands, which lead to system performance deterioration or even instability. This article focuses on the platoon control problem for a group of connected and automated vehicles (CAVs) subject to both deception attacks and external disturbances. First, modeling both attacks and external disturbances as lumped disturbances, and a novel adaptive fixed-time disturbance observer (AFxTDO) without requiring prior knowledge of the disturbance boundary is further constructed to estimate the lumped disturbances within given time with zero estimation errors. Then, a new global fixed-time stability result with faster convergence rate is developed, together with the given AFxTDO, a variable exponent fixed-time sliding-mode control (VFxTSMC) scheme is established, such that the platoon tracking errors can converge to a predetermined region within the given time while avoiding the singularity phenomenon, improving the convergence speed and reducing the number of controller parameters. Meanwhile, individual vehicle stability and string stability also can be guaranteed within fixed-time by the suggested control scheme. Finally, the simulation results reveal the effectiveness and superiority of the proposed algorithm.

This study investigates the online optimization control problem for a vehicular platoon in the presence of unmodeled vehicle dynamics, unknown external disturbances, and uncertain inter-vehicle communication topology. A novel practical performance-prescribed reinforcement learning-based distributed sliding mode (PRLDSM) control framework is constructed for the platoon to strengthen the robustness and possess the online self-learning capacity for optimizing and control. Specifically, a composite controller is proposed for the platoon which consists of an online optimal controller and a sliding mode controller. By the strong learning capacity provided by the PRLDSM controller, the optimal policy and cost function can be recursively approximated by online simultaneous tuning of both actor and critic neural networks. Moreover, it is proved that all the signals in the closed-loop platoon control system are uniformly ultimately bounded and approach zero by selecting appropriate parameters. Theoretical analysis eventually guarantees that the tracking errors can be stabilized to satisfy both the individual vehicle stability and disturbance string stability with the prescribed transient response and steady-state accuracy. The obvious feature of the proposed PRLDSM controller is that the requirement of the exact vehicle dynamics and topological matrix of the inter-vehicle communication topology can be avoided. Both numerical examples and experimental studies illustrate the effectiveness of the proposed control method.

Emerging technologies of connected and automated vehicles (CAVs) applied at intersections have great potential to improve traffic efficiency, driving safety, and fuel economy. This paper proposes a virtual spring strategy for coordinating CAVs to pass through signal-free intersections. A virtual spring coordination system (VSCS) is established to force the movements of conflicting CAVs in terms of spring characteristics. Inspired by the properties of springs with dampers, a distributed control protocol is designed to regulate CAVs to reach a desired state of motion when crossing intersections. For ensuring the convergence of the VSCS, i.e., the total elastic potential energy approaches to zero, sufficient conditions for the internal stability are derived subject to the input saturation. To further improve the anti-disturbance capability of the VSCS, we ensure the upper bound of the disturbance propagation, which is characterized by an$H_{\infty }$performance index. The proposed strategy is developed in a receding horizon framework and tested under the two scenarios in simulations. The simulation results show the effectiveness and superiority of the proposed strategy.

This paper proposes a privacy-preserving distributed collaboration (PPDC) scheme for connected autonomous vehicles (CAVs) to cross signal-free intersections based on the cloud, while securing the private data of the vehicles. Firstly, this paper converts the cooperation problem into a multi-objective problem that aims to improve the efficiency of traffic and fuel economy. Secondly, to prevent the privacy of the transmitted data of vehicles from being inferred by untrusted cloud servers or external attackers, an affine masking-based privacy strategy is designed. Specifically, the vehicle first uploads the encrypted state data to the cloud with the affine masking method. Then the cloud returns the control input by solving the newly constructed optimization problem, which is different but equivalent to the original problem. Then the vehicle calculates the real control input by the inverse affine masking mechanism. Simulation examples show that the proposed PPDC scheme can guarantee collision avoidance and the privacy protection of transmitted data of CAVs, improve traffic efficiency as well as fuel economy, and avoid extensive computation burden.

In this paper, the distributed security control problem of connected vehicle systems (CVSs) is investigated under denial of service (DoS) attacks and uncertain dynamics. DoS attacks usually block communication channels, resulting in the vehicle inability to receive data from the neighbors. In severe cases, it will affect the control performance of CVSs and even cause vehicle collision and life threats. In order to keep the vehicle platoon stable when the DoS attacks happen, we introduce a random characteristic to describe the impact of the packet loss behavior caused by them. Dependent on the length of the lost packets, we propose a security platoon control protocol to deal with it. Furthermore, the security platoon control problem of CVSs is transformed into a stable problem of Markov jump systems (MJSs) with uncertain parameters. Next, the Lyapunov function method and linear matrix inequations (LMI) are used to analyze the internal stability and design controller. Finally, several simulation results are presented to illustrate the effectiveness of the proposed method.

This paper studies the problem of designing the load frequency control (LFC) scheme for the inter-connected multi-area power systems (MAPSs) with asynchronous sampled-data coomunication and missing control inputs. Due to the effect of asynchronous sampled-data communication and missing control inputs, the MAPS is modeled as sampled-data switched systems. By using the modeling transformation technique, MAPS is further represented as a time-delay switched system with multiple time delays. Combined with average dwell time technique and time-delay systems analysis approach, a series of conditions are obtained for MAPS to maintain grid frequencies and tie line power exchanges with neighborhood areas at scheduled values. Moreover, the relation between the stability and the control inputs missing rate is established and the upper bound of the allowable control inputs missing rate is found. Based on those obtained condition, a useful algorithm is proposed to solve the controller gain for the area control error based sampled-data LFC. The designed LFC scheme not only can guarantee the stability of the MAPS but also can reject the effect of load disturbance. The applicability of the proposed design method is validated by a numerical example with inter-connected three-area power systems.

This paper investigates the platoon control problem for vehicular cyber physical systems (VCPSs) under Denial-of-Service (DoS) attacks and multiple disturbances. DoS attacks often make data packets congested or even lost by jamming communication channels, which will lead to performance degradation of the VCPSs or even vehicle collisions. To counter DoS attacks, a recovery mechanism is introduced to confine the time duration rate and occurring frequency of the adverse effects of the DoS attacks on VCPSs. In the meanwhile, a resilient platoon control protocol is proposed to achieve internal stability of the VCPSs under DoS attacks. The propagation of disturbances among VCPSs is characterized by an$H_{\infty }$performance index, whose upper bound is ensured by solving conditions related to matrix inequalities. Moreover, a controller design algorithm is proposed to minimize the disturbance propagation bound in the context of DoS attacks. Numerical examples show the effectiveness of the obtained theoretical results.