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Xin Zilin,Wang Wenwei,Liang Sheng 한국자동차공학회 2023 International journal of automotive technology Vol.24 No.4
In order to improve the path following performance and solve the stability problems of autonomous distributed drive electric buses, this paper proposed a path following and lateral-yaw-roll stability integrated control method. Firstly, to cope with the varying speed during different maneuvers and roll motion of autonomous distributed drive electric buses, a nonlinear 4-DOF vehicle dynamic model which includes rolling and longitudinal movement is established. Secondly, a hierarchical control method is built, in the upper layer, a model predictive controller (MPC) is designed to generate the control inputs, which is obtained through an optimization problem including path following error and vehicle stability condition, especially the roll stability for buses, and for the lower layer, the torque of each drive wheel is distributed through solving an optimization problem about drive requirement and tire utilization. Finally, the validation of the proposed method is carried out through TruckSim-Simulink co-simulation, the results illustrate that both following accuracy and vehicle stability are obtained more effectively than the popular linear MPC method, especially roll stability is guaranteed under extreme condition.
Joint Deployment and Trajectory Optimization in UAV-Assisted Vehicular Edge Computing Networks
Zhiwei Wu,Zilin Yang,Chao Yang,Jixu Lin,Yi Liu,Xin Chen 한국통신학회 2022 Journal of communications and networks Vol.24 No.1
As the general mobile edge computing (MEC)scheme cannot adequately handle the emergency communicationrequirements in vehicular networks, unmanned aerial vehicle(UAV)-assisted vehicular edge computing networks (VECNs) areenvisioned as the reliable and cost-efficient paradigm for themobility and flexibility of UAVs. UAVs can perform as thetemporary base stations to provide edge services for road vehicleswith heavy traffic. However, it takes a long time and huge energyconsumption for the UAV to fly from the stay charging stationto the mission areas disorderly. In this paper, we design a predispatchUAV-assisted VECNs system to cope with the demandof vehicles in multiple traffic jams. We propose an optimalUAV flight trajectory algorithm based on the traffic situationawareness. The cloud computing center (CCC) server predictsthe real-time traffic conditions, and assigns UAVs to differentmission areas periodically. Then, a flight trajectory optimizationproblem is formulated to minimize the cost of UAVs, while boththe UAV flying and turning energy costs are mainly considered. Inaddition, we propose a deep reinforcement learning(DRL)-basedenergy efficiency autonomous deployment strategy, to obtain theoptimal hovering position of UAV at each assigned mission area. Simulation results demonstrate that our proposed method canobtain an optimal flight path and deployment of UAV with lowerenergy consumption.
Bo Long,Chu Wang,ZiLin Zhu,Xin Lu,LiJun Huang,YuFei Dai,Yong Liao,FuSheng Li 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5
In the grid-connected inverter controller system, conventional PI or PR controller decrease their lowfrequency gain and bandwidth to maintain the stability of the system. However, this degrades the disturbance rejection and current tracking capability. To solve this problem, this paper gives an H∞ robust control scheme based on Numerator Denominator Model method, which has the advantages of simplified current controller design procedure, can place the poles of closed-loop system at the desired place. By properly selecting the weight function, the proposed control scheme can not only achieve good robustness in disturbance rejection capability, but also gives a straight forward to design the dynamic performance. Simulation and experimental comparison results between PR and H∞ controller is demonstrated. The results prove that the proposed control scheme shows obviously improvements on the robustness of inverter and meanwhile does not lose advantages on the dynamic performance.