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In this research, a method of designing an EPS control system that achieved a good steer feeling without using an actual vehicle was examined. Firstly, evaluation functions to evaluate steer feeling theoretically were set. And it was described that steer feelings such as “inertial feeling” and “viscous feeling” could be expressed by the evaluation functions. Secondly, a target characteristic that made the steer feeling good was determined on the evaluation function, and control methods to theoretically achieve this target characteristic were described. Finally, the designed control system was installed in an EPS vehicle. As a result, it was confirmed that the steer feeling in an actual vehicle was fine with no “inertial and viscous feeling”.

An “Analytical Method of Equivalent Linear System Uning the Restoring Force Model of Power Function Type”, which is used as a non-linear vibration analytical method for vibration systems that shows their characteristics of viscoelasticity, was applied experimentally to vehicle dynamic analysis. This article describes the theory of this analytical method. The analytical method was applied to vehicle dynamic analysis by using it experimentally to analyze vehicle steering force characteristics. We were able to verify the appropriateness and accuracy of this method.

This paper describes the manufacture of a prototype polishing apparatus for curved surfaces utilizing sensor feedback control with a noncontact-type laser sensor, and construction of the circumference system. With respect to the work shape measurement with a noncontact sensor, it was clearly shown that the contouring error was affected by sensing error, and it was possible to decrease the contouring error by correcting the sensing error. Concerning the tool attitude control in which the tool spindle usually rotates in the normal direction to the work surface during polishing, a new mechanism was designed. After the cutting experiment, improvement of machined surface and effectiveness of the new control mechanism were confirmed.

Sample preparation 1st report (WC/12Co) Nitrogen gas nano-sized WC no decarbridization 1200HV 2nd report (WC/12Co) Helium gas nano-sized WC no decarbridization 2050HV [2] [3-4] Cold spraying, one of the coating formation techniques can accelerate feedstock powders to deposit onto substrates only using high pressure gas with lower temperature of melting point of the feedstock.[1] Therefore, the low temperature melting metals have been widely investigated, such as Al and Cu up to now. High temperature melting metals of Nb and Ta have become target by the progress of the cold spraying apparatus, such as increasing gas pressure, gas temperature, powder feeding methods and nozzle design. As for hard and brittle materials of ceramic and cermet, this method has been considered to be difficult to apply in general. Recently, some researches revealed that WC cermet coatings were formed by the cold spraying, where nano-scaled WC particle is effective to increase coating density and hardness. [2-4] However, no investigation has been conducted about wear properties of such a cold sprayed WC cermet coating, as far as we know. In this work, we have investigated influence of WC particle size, powder size and Co content on structural and mechanical properties of cold sprayed WC/Co coatings. Also, the properties have been compared with conventional HVOF coatings. [1] A.P.Alkimov et al.: USPatent5302414. [2] R.S.Lima et al.: Thin Solid Films 416, p129 (2002). [3] H-J.Kim et al.: Surf. Coat. Technol. 191, p335 (2005). [4] H-J.Kim et al.: Mater. Sci. Eng. A391, p243 (2005).