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This paper is dedicated to the study and improvement of the aerodynamic properties of the feeder airship in the context of MAAT project. FP7 MAAT project is based on the concept of two different types of airships (the cruiser and the feeder) working together as a transportation system. The current feeder concept includes unconventional shape changing envelope. Two problems are considered in this paper. The first problem is to find a condition of the effective vertical ascent for the feeder (from the ground to the altitude of the cruiser). A series of CFD simulations were carried out for the top flow for a range of altitudes from 0 to 16 km and velocities between 2 and 10 m/s. The results confirm the appearance of some negative effects, including high drag during the vertical ascent, especially, at low altitudes. The second problem is to study and reduce the side wind effects on the ascending feeder airship.

The aim of the study was to investigate the difference between car-to-e-bikes and car-to-pedestrian accidents. The China In-depth Accident Study (CIDAS) database was searched from 2011 to 2013 for pedestrians and e-bikes struck by car, van and SUV fronts, which resulted in 104 pedestrian and 85 e-bike cases where information was sufficient for in-depth analysis. Reconstruction by PC-Crash was performed for all of the sampled cases. Pre-crash parameters were calculated by a MATLAB code. Focus was on prototypical accident scenarios and causes; speed as well as possible prevention countermeasures. It has been shown that traffic light violations, road priority violations, and unsure safety (these situations included misjudgments, unpreparedness, proximity to other road users, inappropriate speeds, etc.…) are the main causes in both the VRU groups. Distinctions were found for aspects of car collision speed, accident scenario, distribution of head contact points and so on.

In helicopter, the icing rotor blades will decrease the effectiveness of the helicopter and endanger the lives of the pilots. The asymmetrical ice break-up and shedding could also lead to severe vibrations of the rotor blade. Ice break-up from the main rotor may strike the fuselage and tail rotor, even worse, find its way into the engine, which may cause serious aircraft accidents. An understanding of the mechanisms responsible for ice shedding process is necessary in order to optimize the helicopter rotor blade design and de-icing system to avoid hazardous ice shedding. In this paper, the ice shedding model is improved by introducing a bilinear cohesive zone model (CZM) to simulate the initiation and propagation of ice/blade interface crack. A maximum stress criterion is used to describe the failure occurred in the ice.

In order to achieve a good shifting quality of pure electric vehicle dual-clutch transmission, this paper adopts linear active disturbance rejection controller (LADRC) to control the shifting strategy. For the uncertainty of transmission dynamics model parameters and the existence of unknown disturbance effects, the linear expansion state observer (LESO) can be used to estimate and compensate the disturbance. The shift control process is converted into tracking the motor speed and clutch speed trajectory, and the linear feedback control law is used to control the motor torque and the solenoid valve current. The simulation and test results show that the control algorithm is effective and good shifting quality is guaranteed.

This paper proposes a hybrid carrier spread spectrum modulation (HCSM) technique based on dynamically adjusting the spatial zero-vectors action time to suppress the sideband vibro-acoustic responses introduced by the discontinuous pulse-width modulation (DPWM) in permanent magnet synchronous motor (PMSM) for electric vehicles (EVs). Firstly, the space vector principle of DPWM is presented, and the relationship between current harmonics and space zero-vectors is analyzed. Then, the HCSM technique is proposed to suppress the current harmonics and vibro-acoustic responses based on the variation trend of zero-vectors action time in six sectors, and the suppression effect of HCSM on sideband components is predicted by the finite element method. Finally, with a 12-slots/10-poles prototype PMSM, the sideband vibro-acoustic responses and the electric drive system loss caused by DPWM and classical space vector pulse-width modulation (SVPWM) before and after using HCSM are analyzed.

In order to improve the path tracking accuracy of driverless vehicles at different speed, a fuzzy adaptive model prediction control method was proposed to adjust constant predictive horizon of MPC. Based on the MPC method of 3-DOF vehicle dynamics model, prediction horizon and weight coefficient of the MPC controller could be varied in real time according to the speed and road curvature. With the desired path as the target, the front wheel angle was changed to achieve path tracking. Simulation analysis was performed under the CarSim/Simulink co-simulation environment. Simulation results show that under the condition of satisfying ride comfort and stability of vehicle, the tracking error of the proposed method in the path tracking control is reduced by 30.0%, 29.9% and 14.6% at 36km/h, 72km/h and 108km/h, respectively, which are helpful to path tracking control.