Mechanical and control design of caster for low vibrations and crashes of carts

This paper presents the mechanical and control design of a caster to reduce the impulsive accelerations and residual vibrations of carts. The main theme is to remove the cart disturbances from roads by mechanical and control design. The mechanical design based on the center of percussion of the caster is proposed to reduce the impulsive accelerations caused by road bumps, and the reduction effect for the cart is confirmed by experiments. Then what is called a skyhook control is applied to reduce the residual vibrations after running over road bumps. The simple skyhook control is proposed by using only the absolute velocity and acceleration, and is verified to be effective in the reduction of both the vibration and the impulsive acceleration toward the cart by experiments.