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Most passenger vehicles employ manual or automatic transmission in their power train. Recently, some automated geared transmission including the dual clutch transmission is gaining popularity for its fuel efficiency and smooth driving as well as convenience. In this study, we are proposing a new much simplified clutchless geared transmission which may transmit most powerful torque employing the power-merge planetary gear system to the final drive during gear shift with excellent smoothness in the transmitted torque. This transmission might work for the most kinds of vehicles having internal combustion engine including the hybrid vehicles.

Upon the need of a highly efficient transmission system for conventional cars and the hybrid electric vehicle (HEV) purposes, in the paper, clutchless geared transmission system (CGST) by removing the clutch and incorporating a planetary gear system connected to a motor is newly proposed. The dynamic analysis of CGST operations is carried out, using the lever analogy of planetary gear. The state space model and the mathematical model of CGST structure are derived. Through the simulations of CGST operations, input-output tests and gear shifts are performed. To verify the simulation result, reduced size of CGST testbench is developed and experimented.

Nonlinear and linear state equstions of 3 dof vehicle model for steering are derived by a symbolic computation software, MACSYMA. As these state equations are in symbolic form, the vehicle design variables for steering can be derived also in closed form. Then by putting the poles of the linear state equation to those of the optimal closed loop, an improved tunning of the vehicle steering response is obtained for two wheel steering vehicle.