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Based on the concept of component assembly, a novel star polygon-coupled honeycomb metamaterial, which achieves a collaborative improvement in load-bearing capacity and vibration suppression performance, is proposed based on a common polygonal structure. The compression simulation and experiment results show that the load-bearing capacity of the proposed metamaterial is three times more than that of the initial metamaterial. Additionally, metal pins are attached and particle damping is applied to the metamaterial to regulate its bandgap properties; the influence of configuration parameters, including the size, number, position, and material of the metal pins, on bandgaps is also investigated. The results show that the bandgap of the proposed metamaterial can be conveniently and effectively regulated by adjusting the parameters and can effectively suppress vibrations in the corresponding frequency band. Particle damping can be used to continuously adjust the frequency of the bandgap and further enhance the vibration suppression capacity of the metamaterial in other frequency bands. This paper provides a reference for the design and optimization of metamaterials. [ABSTRACT FROM AUTHOR]

The Innovative Movable-teeth CVT（ iMCVT） is a new type of non-friction continuously variable transmission,in the process of transmission,there will be fluctuations in rotational speed and torque. In order to investigate the influence of the tension to the fluctuations of the rotational speed and torque,based on the structure and work principle of iMCVT,the causes of iMCVT fluctuations are analyzed. Based on ADAMS,the dynamics simulation model is built. The effect of tension force on the iMCVT transmission fluctuation is studied by changing the tensioning force of the tensioning device on the metal tooth chain. The simulation results show that when the transmission ratio is 1,increasing the tension force can reduce the fluctuation of the rotational speed,when the tension force reaches a certain value（ about 600 N）,the fluctuation of the rotational speed tends to be stable. On this basis,through the formula to calculate the transmission efficiency curve,and in a certain range,increase the tension can improve the transmission efficiency,too much tension can lead to the decline of transmission efficiency. The results of this study laid the foundation for the control of iMCVT tension.

In order to investigate the torque transmitting ability of the innovative Movable- teeth CVT（ i MCVT）,its construction and principle are analyzed,and then,a comparative analysis with the torque transmitting ability of the metal belt continuously variable transmission which is based on friction transmission is carried out. Lastly,the transmission efficiency test platform is set up to investigate the relationship between the transmission efficiency and the transmission torque of the i MCVT under three conditions. The results show that when the i MCVT operating stable under three conditions, the transmission torque could reach to about 220 N·m. When the transmission torque is at 180 220 N·m,the i MCVT transfer stably and the transmission efficiency is high. Compared with the metal belt continuously variable transmission,the torque transmitting ability of i MCVT is stronger,and still could keep the high transmission efficiency of 92% when transferring the high torque.

Regenerative braking is an important technology to improve fuel economy for electric vehicles. Apart from improving energy recovery efficiency and vehicle stability, the arithmetic speed of the algorithm is also essential for an automotive-qualified micro control units. This paper presents a direct multiple shooting method–based algorithm to achieve multiple objectives for four hub-wheel-drive electric vehicle during mild braking situations. Mathematical models of the system are generated for numerical simulations in MATLAB, including a vehicle dynamics model, a modified tire model, a single-point preview driver model, and a regenerative braking motor efficiency map. With the limitation of hard constraint and minimization of adjustment rate in cost function, optimization tends to be accomplished by distribution of braking torque in front and rear wheels. Furthermore, the control strategy has been realized using a direct multiple shooting method to convert the nonlinear optimal control problem to a nonlinear programming problem, which will be settled by adopting a sequential quadratic programming method in each subintervals. The effectiveness and adaptation of the control strategy for four hub-wheel-drive electric vehicle has been evaluated by conducting many simulations during mild braking situations, and the simulation results also demonstrated that the direct multiple shooting–based strategy exhibits a better performance than that of proportional-integral-based or nonlinear model predictive control–based controller. [ABSTRACT FROM AUTHOR]