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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.

Electric vehicles (EVs) have attractive potential not only for energy and environmental performance but also for vehicle motion control because electric motors have quick and measurable torque response. Recently, the authors' laboratory has developed a completely original EV which has active front and rear steering systems and high-torque direct- drive in-wheel motors in the all wheels. In this paper, the main features of this vehicle are briefly introduced and our recent studies on pitching control, slip-ratio control, and yaw-rate and slip-angle control with lateral force sensors are explained with experimental results.

In this paper, the range extension control system based on least square method is proposed for electric vehicles with in-wheel motors and front active steering. This proposed method distributes front and rear wheel side-slip angles and driving force difference between left and right motors from lateral force and yaw-moment. The proposed method enables to reduce driving resistance generated from front steering angle. In fact, the mileage per charge is extended up to 200 m/kWh. Simulations and experiments are carried out to confirm the effectiveness of the proposed method.

We started to fabricate 4um design rule SOI (Silicon On Insulator) smart power ICs since 1996 for automotive applications. Now we developed 0.8um design rule SOI smart power ICs. These ICs are using trench dielectric isolation technology, employing an SOI wafer and deep trench etching. This technology could be used to integrate 0.8um CMOS transistors as digital devices, DMOS (Double diffused MOS) transistors as power devices, high breakdown voltage bipolar transistors as analog devices, and to create thin film resistors for high precision resistance, which could be trimmed using a laser. SOI smart power ICs suits various ECUs (Electronic Control Units) and smart actuators for automotive applications, due to its non-parasitic elements and high temperature operation. We describe the requirements of devices for automotive applications and the features of SOI Smart Power ICs.

The shock absorber of suspension has two important basic functions. One is to control vehicle attitude changes when steering and when accelerating and decelerating, and the other is to dampen forces transmitted from the road by its damping effect, thus softening shocks. The characteristics of these two demands in performance, driving stability and riding comfort, conflict with each other but are selected from the concept of a car and from coaching by users. Namely, someone puts stress on driving stability and the other puts stress on riding comfort. Electronics have advanced in recent years and the use of electronic absorber control systems in order to achieve both driving stability and riding comfort has become widespread first of all in Japanese vehicles and also in European and American vehicles. Toyota first developed its TEMS (TOYOTA ELECTRONIC MODULATED SUSPENSION) in 1983 (1) and since then many improvements have been added.