Abstract
In compact robots, the chassis is usually made with two independent drive wheels and two passive wheels or balls, while the turn is carried out like a tank. But in robots, for example, the number of chassis engines is often limited, including by the rules of the competition, and by the fact that the number of engines in simple Lego robots is limited. For a tank turn, the driven wheels must provide minimal resistance to lateral drift during a turn, but when moving straight, these wheels must support rectilinear motion as much as possible. This is a contradiction. By the way, yaw is not harmless either - frequent yaw makes noise in the gyroscope. We proposed and implemented a scheme with a "Fifth Wheel" - a wheel that extends only during the turn, perpendicular to the longitudinal axis of the robot, raising the passive wheels for a turn. We designed, tested and built a robot using a 5-wheel scheme.