Abstract
A mechanism for auto-landing operation of self-propelled carriage has been developed as an automation technique for one-man yarding. To achieve accurate auto-landing, it is necessary to accurately detect when the load that is suspended from a hoisting cable becomes a "no load" by landing. Therefore, we measured the load that was suspended on a hoisting cable based on the hydraulic motor pressure of the hoisting winch drive, and designed a technique for detecting the moment when pressure begins to decrease and the moment when there is "no load" from the viewpoint of easiness of remodeling and not ruining an original mechanism. When pressure reaches no load, the winch is stopped. In this method, there is little change in hydraulic pressure and detection becomes impossible when the load is light. Therefore, the boundary between correct and incorrect detection was calculated. The results of a corroborative experiment using an iron weight were roughly the same as the calculated values. The boundary value was about 100kg from a suspension height of 10m which, although a slightly large value, would be the range that the work can be done and could still enable automatic operation to be done accurately. Landing work that did not need a human worker became possible by combining this new method with an automatic unloading hook.
