| 摘要 |
An apparatus controlling an overhead crane in a manner that reduces the likelihood that the crane and objects suspended therefrom will contact another object. This apparatus comprises a standard control panel for controlling the speed and direction of the crane based on a plurality of operator control signals and a collision avoidance system. The collision avoidance system comprises (a) an ultrasonic transceiver for generating an ultrasonic signal and receiving a reflected ultrasonic signal that has been reflected off of the other object, the reflected ultrasonic signal being indicative of a distance between the crane and the other object; (b) means for generating an analog ranging signal based on the reflected ultrasonic signal, the level of the ranging signal being substantially proportional to the distance between the crane and the other object; (c) a plurality of relays; and (b) relay driver means associated with each of the relays for operating the relay associated therewith, the relay driver means being operator adjustable to allow the relays associated therewith to be operated based on a desired level of the ranging signal. The relays are so arranged and the relay driver means are so adjusted that, when the crane is likely to contact the other object, the relay driver means so operates the relays that the relays cause the control means initially to limit the speed of crane and then to stop the crane. With switches controlled based on a direction of travel of the crane, more than one ultrasonic transceiver may be employed.
|
