| 摘要 |
A method and apparatus for measuring distance on a loose surface is disclosed. The apparatus includes a frame and a wheel operatively coupled to the frame. The wheel rotates relative to the frame. Further, the wheel includes a hub for operatively coupling the wheel with the frame. The hub rotates relative to the frame in response to one of pushing and pulling of the frame. To increase traction between the wheel and the loose surface, a plurality of spikes is provided on a peripheral surface of the wheel, projecting outwardly away from the hub. As the peripheral surface rolls on the surface, the distance traversed by the wheel is measured by calculating the number of rotations made by the wheel. A counter is operatively coupled to the wheel for tracking the number of rotations made by the wheel as the peripheral surface of the wheel rolls on the loose surface. |
