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Vehicle lateral states such as lateral distance at a preview point and heading angle are indispensable for lane keeping control systems, and such states are normally estimated by fusing signals from an onboard vision system and inertial sensors. However, the sampling rates and measurement delays are different between the two kinds of sensing devices. Most of the conventional methods simply neglect measurement delay and reduce sampling rate of the estimator to adapt to the slow sensors/devices. However, the estimation accuracy is deteriorated, especially considering the delay of visual signals may not be constant. In case of electric vehicles, the actuators for steering and traction are motors that have high control frequency. Therefore, the frequency of vehicle state feedback may not match the control frequency if the estimator is infrequently updated. In this paper, a multi-rate estimation algorithm based on Kalman filter is proposed to provide lateral states with high frequency.

The wireless charging system of electric vehicles will be of high power. Due to environmental problems and the heat emission design of the machines, it is not easy to improve the efficiency of the power transmitting system. While improving the efficiency of the overall system is important, it is especially significant to improve the efficiency of the transmitting and receiving antennas. Improving the antennas is necessary as it accounts for a large part of the overall efficiency and it has strong relation to the transfer characteristics. In this paper, the importance of reducing the antenna loss for high power implementation is discussed. We showed that the antenna losses not only affecting the transfer efficiency but also the maximum power consumed by the load (the available power) by deriving an equation.

This year is being called the “first year of electric vehicles,” and electric vehicles have come on the market in earnest. This trend is expected to continue and even accelerate with the diffusion of electric vehicles. However, manually charging the battery for electric vehicles is a tedious process. Therefore, an automatic, wireless charging system for electric vehicle is greatly desired. There are some types of wireless power transfer systems. In particular, electromagnetic resonant coupling is a promising technology for wireless power transfer because power can be transferred over a large air gap; this method is more practical and efficient than the conventional methods. This technology has been proposed recently, and detailed study on the repeater antenna is yet to begin.