In this paper, a novel two-channel event triggered adaptive fault-tolerant control approach is designed to handling the degree freedom nonlinear system with disturbance. The main purpose of this study is to maintain the output tracking ability while reducing the transmission burden. The objective is realized by designing a novel adaptive sliding mode controller integrated with the event trigger mechanism. Concretely, the state, actuator fault, and lumped disturbance information are obtained by designing a composite observer, in which the disturbance upper bound is not needed. Then, the obtained information is utilized to design the controller. In the proposed method, the lumped disturbance and nonlinear estimated values are contained in the sliding mode manifold to enhance the robustness. Additionally, an adaptive parameter is also integrated into the controller to compensate for the disturbance. Furthermore, a specific event triggered controller is proposed to keep the tracking ability and reduce the transmission load of the fault system. The no Zeno phenomenon performance is analyzed and, finally, the application to the suspension system is given to show the fault tolerance ability of the proposed method.

The existing energy management strategies for four-wheel-drive electric vehicles only take into account the vehicle energy consumption under static adhesion constraints. However, the front and rear axle loads transfer under dynamic conditions lead to the variations of vehicle adhesion characteristics, which results in the changes of vehicle energy consumptions. In this paper, a multi-objective optimal torque distribution strategy is proposed, taking into account the front and rear axle load transfer and the variations of adhesion characteristics. The advantages of the proposed strategy are verified through simulation studies in terms of vehicle energy consumption and wheel slip ratio, in comparison with the average torque distribution strategy and the optimal torque distribution strategy based on Sequential Quadratic Programming Algorithm. The simulation results show that the economy performance of the proposed strategy is superior to those of the competing methods. Furthermore, the proposed strategy provides good power performance and eliminates excessive wheel slip, which in turn ensures vehicle longitudinal stability and avoids energy loss resulting from frequent ASR interventions.

This article presents an active fault-tolerant control (FTC) approach for four-wheel drive-by-wire (4WDW) electric vehicles (EVs) with unmatched disturbance, whose purpose is to preserve stability and improve the tracking performance under actuator fault. The proposed scheme is divided into four steps. First of all, an unmatched nonlinear disturbance observer (NDOB) is established based on the 4WDW EV model to estimate the equal disturbance and compensate for the modeling error. Then, a state tracker with estimated unmatched nonlinear disturbance is designed. Followed by the design of a novel adaptive sliding mode fault-tolerant control (ASM-FTC) strategy based on NDOB. Finally, control efforts allocate according to the degree of motor failure. On the one hand, controller parameters are capable of self-adaptively reconfiguring such that a faster convergence can be realized. On the other hand, better tracking performance is guaranteed with the application of estimated disturbance information in the control law. Hardware-in-the-loop (HIL) simulation results illustrate the validity of the proposed method in various driving scenarios.

Vehicular ad hoc networks (VANETs), an application of the Internet of Things (IoT) providing a better intelligent transportation system (ITS), has received substantial attention from both industry and academia. Heterogeneous vehicular communications in VANETs occur when both vehicles and the infrastructure use different cryptographic technologies to exchange safety messages. However, the safety messages between vehicles and the infrastructure are communicated wirelessly; therefore, security issues are a serious concern in this domain. The existing schemes secure the transmission of safety messages with respect to confidentiality, authentication, and nonrepudiation. However, they are inappropriate with respect to efficiency. They cause computational overhead on the receiver and bandwidth overhead in the communications. To cope with this, we propose an elliptic curve cryptosystem-based hybrid signcryption (ECCHSC) protocol that satisfies the security requirements (i.e., message confidentiality, message’s source authentication, message integrity, nonrepudiation, and identity–anonymity) for heterogeneous vehicle-to-infrastructure (V2I) communications in a single logical step. This protocol allows secure transmission of a safety message from a vehicle using identity-based cryptography (IDC) to a roadside unit (RSU) using public-key infrastructure (PKI). In addition, the ECCHSC protocol enables the RSU to receive multiple ciphertexts, aggregate them, and de-signcrypt them simultaneously through the batch de-signcryption method, which further improves the performance. The ECCHSC protocol has indistinguishability against adaptive chosen ciphertext attacks (IND-CCA2) and existential unforgeability against adaptive chosen message attacks (EUF-CMAs) in the random oracle model (ROM). The performance analysis of our protocol demonstrates a significant reduction in computational overhead and in communication/storage overhead as compared to the state-of-the-art schemes.

To better predict the high-frequency switching operation of the half-bridge circuit in power converters, the value of the parasitic elements of these devices must be accurately evaluated. A new MOSFET-based half-bridge circuit parasitic inductances extraction method using two-port S-parameters is proposed in this paper. By changing the terminal connection of the half-bridge circuit, we can treat it as several different two-port networks, and then detailed network analysis can be performed on it. The parasitic parameters of multi-terminal actual circuits such as half-bridge can be extracted accurately and quickly through the simple measurement steps and calculations of the proposed method.

Dual active bridge (DAB) converter is widely used in electric vehicles due to its advantages of electrical isolation function and bi-directional energy flow. However, compared with other converters, the number of switching tubes is large and the internal structure is complex, and the electromagnetic interference at the input and output ends is more serious. In this paper, a predictive behavioral model is established to predict the common-mode (CM) conducted electromagnetic interference (EMI) on both sides of DAB converter. First, the converter is treated as a linear two-port network. Secondly, the impedance of the two-port network in the common-mode loop is calculated from the extracted S-parameters of the converter. And then an equivalent model is established to predict the conducted EMI combined with the common-mode current of the input and output bus. Finally, the proposed model is verified by experiments on a 140W DAB converter system.