Study on design methodology of power-assisted luggage cart with rotational arms for stair climbing

Power-assisted luggage carts that are capable of climbing stairs using actuated rotational arms with unactuated wheels at the ends of the arms are proposed. A unified optimum design, including the number of arms, is analyzed and discussed from the perspective of motion smoothness and assist capability. With the appropriate selection of the number of arms and dimensional design of the arm length and wheel radius, the motion fluctuation can be reduced to less than 40 mm on stairs with normal going and riser dimensions. It was found that the mechanical work by the operator could be reduced to one fourth using the proposed mechanism with rotating arms by an actuator.