SMART ONE-HAND OPERATION MECHANISM FOR MULTI-PURPOSE STEERING OF A FOUR-WHEELED VEHICLE

We propose a manually controllable smart mechanism for changing locomotion types of a 4-wheeled vehicle. Our locomotion types include direct moving toward the front and rear, turning toward the right or left, and spinning, but also braking without using special disc or shoe pads. These types are possible when external motors drive locomotion power. For instance the power is supplied by a user when the vehicle is a walker. To make it easy to maneuver the walker toward the direction of the destination, we designed a joystick, which is operated by hand without using electric power or instruments. It is basically composed of a differential gear mechanism. However, it is assembled using irregular gears to satisfy the Ackerman-geometry so that the walker can turn easily with one-hand operation. We show the design of the force transmission mechanism using an irregular gear made up of two different plain gears in pitch circle diameter. Also, we show how the mechanism works since the vehicle steering is an oscillatory motion operation.