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The capacity of improving the control accuracy and dynamic performance of a four degreeof-freedom (DOF) permanent magnet biased active magnetic bearing (PMBAMB) system is critical to developing and maintaining a high precision application in a magnetically suspended direct-driven spindle system. The 4-DOF PMBAMB system, however, is a multivariable, strong coupled and nonlinear system with unavoidable and unmeasured external disturbances, in addition to having parameter variations. The satisfactory control performance cannot be obtained by using traditional strategies. Therefore, it is important to present a novel control scheme to construct a robust controller with good closed-loop capability. This paper proposes a new decoupling control scheme for a 4-DOF PMBAMB in a direct-driven spindle system based on the neural network inverse (NNI) and 2-degreeof-freedom (DOF) internal model control method. By combining the inversion of the 4-DOF PMBAMB system with its original system, a new pseudolinear system can be developed. In addition, by introducing the 2-DOF internal model controller into the pseudolinear system to design extra closed-loop controllers, we can effectively eliminate the influence of the unmodeled dynamics to the decoupling control accuracy, as well as adjust the properties of tracking and disturbance rejection independently. The experimental results demonstrate the effectiveness of the proposed control scheme.

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Flexible lithium–sulfur (Li–S) batteries with high mechanical compliance and energy density are highly desired. This manuscript reported that large-area freestanding MXene (Ti3C2T x ) film has been obtained through a scalable drop-casting method, significantly improving adhesion to the sulfur layer under the continuously bent. Titanium oxide anchored on holey Ti3C2T x (TiO2/H–Ti3C2T x ) was also produced by the well-controlled oxidation of few-layer Ti3C2T x , which greatly facilitates lithium ion transport as well as prevents the shuttling of lithium polysulfides. Therefore, the obtained sandwich electrode has demonstrated a high capacity of 740 mAh g–1 at 2 C and a high capacity retention of 81% at 1 C after 500 cycles. Flexible Li–S batteries based on this sandwich electrode have a capacity retention as high as 95% after bending 500 times. This work provides effective design strategies of MXene for flexible batteries and wearable electronics.

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In this paper, we present a coordinated control system of differential and assisted steering for in-wheel motor driven (IMD) electric vehicles (EVs) with two independent front-wheel drives. An electric differential (ED) control strategy is proposed to track the expected yaw rate based on sliding mode control (SMC). Meanwhile, to realize differential drive assisted steering (DDAS), a variable speed integral PID controller is used to follow the ideal steering wheel torque. The impacts of the coupling with the ED and DDAS systems on EVs are analyzed, and a coordinated control system with adaptive weighting dependent on vehicle speed is designed. Results of the simulation on the CarSim-Simulink joint platform for IMD EVs model show that the proposed coordinated control approach can effectively reduce the torque of a steering wheel while ensuring the vehicle's stability. Finally, road testing results of IMD EVs are demonstrated to be comparable with joint simulations, indicating the correctness of this solution.