1、中文 2295 字 Application of GPS on Yard Cranes Abstract： GPS is a satellite navigation and positioning system developed by America. Through 24 satellites evenly distributed in the air， the system ensures that positioning information could be well received all over the world at any time. Since the syste
2、m was put into operation， it has been widely applied to uses such as oil surveying， ship and aircraft navigation， construction positioning and military operation. Key Words: GPS , cranes, Port Machinery GPS is a satellite navigation and positioning system developed by America. Through 24 satellites
3、evenly distributed in the air， the system ensures that positioning information could be well received all over the world at any time. Since the system was put into operation， it has been widely applied to uses such as oil surveying， ship and aircraft navigation， construction positioning and military
4、 operation. ZPMC began the study of GPS application on yard cranes two years ago with the purpose of providing the RTG with functions such as reliable straight traveling of gantry and automatic container management like RMG (Rail Mounted Crane) while keeping the RTG of its flexibility on yard changi
5、ng(through longitudinal traveling). The GPS products developed by ZPMC have a positioning accuracy a round15mm and could be widely applied on yard cranes for functions like gantry auto-steering，gantry auto-traveling and automatic container management More than 50 sets of GPS products have been opera
6、ting on ports in Hong Kong， Oman and Shanghai. Application of GPS on Yard Cranes Application of GPS on Yard Cranes It has been long known that the RTG， due to its ability of changing operation yard easily via wheel turning and longitudinal travel， is the favorite choice of many ports when ordering n
7、ew equipment Due to the fact that RTG has no fixed rail however， the function of the gantry steering and position tracking are not well solved，which brings the following drawback： 1.Gantry steering work is becoming more difficult following that the RTG is becoming large r and quicker； 2.Rapid growth
8、 of international trade and container transshipment are making the stacking arrangement and operation management of containers more difficult； if the RTG is not tracked， it is inevitable that the container may be misplaced-such a mistake will result in expensive loses； 3.Automation development of RT
9、G is being hindered due to the shortcoming of gantry it now becomes critical to developing gantry automation while trolley and hoist of RTG has been automated to some extent； 4.Synchronous control of gantry usually is difficult to reach for large span RMGQC In the case that gantry on seaside and lan
10、dside don t travel at same speed， the crane will present skew phenomena and its performance will be degraded. such as “critical path method” to manage the operation more efficiently. 2. Auto-steering of gantry for RTG No maker how high and quick the RTG is， by making use of the “vitual rail” from GP
11、S， excellent gantry autosteering of RTG could be realized thus the RTG Could travel very straight like an RMG and potential gantry collision with other RTG vehicles is eliminated； operators also could be relieved from the fatigue of manual steering. 3. Gantry auto traveling of RTG with position data
12、 (initial and destination position) from the GPS system the RTG could have gantry auto traveling function at the same lane. 4. Fault free operation of RTG By combining gantry position from GPS and positions from trolley and hoist an “e-map” of containers on the yard could be set up The RTG could be
13、so designed that its operation is only possible when the directed container from control center is coincide with the real container(by comparing the positions) 5. Automatic container management with gantry tro1ey hoist position information of the RTG messages including the operation status， current
14、position etc could be sent all the time to the control center； In that way stacking profile of the yard could be continuously updated and manual operation statistics could be reduced to a minimum； 6. Synchronous control for largespan RMG or QC large span RMG or QC is liable to having slipping proble
15、m during gantry t raveling which in turn resents skew phenomena； then the performance of the crane will decrease. With position monitoring on both seaside and land side Synchronous control could be used to remove this problem； 7. AGV navigation traveling of AGV could be remotely controlled with the
16、help from GPS data； 8. Position monitoring for container truck the GPS product could also be applied on container trucks for position monitoring. Application of GPS on container operation management The traditional mode of container operation in many ports is： firstly， in the operation department， i
17、nformation on the containers to be operated would be stored in a main computer； Secondly， the operation message for a certain container with container ID and its position will be sent via radio to an RTG Thirdly the RTG operator will drive the RTG t finish the operation； Finally， the completion of t
18、he operation will be acknowledged by the operator in that sequence, some potential problem may occur: 1.the positions of the RTGS are not clearly indicated and RTG having optimal path cant be selected； the cost then increases； 2. there is no monitoring of the container， then the container may be mis
19、placed： 3. manual interference for acknowledgement is required. However the whole operation could be made in a closed loop by computers without any potential mistake involved by equipping RTGs with GPS. Also the efficiency could be raised greatly See the charts for details. Technical data of the GPS
20、 from ZPMC 1 System configuration 1). The whole project of RTGs will be equipped with one GPS base station it consists of a dualfrequency GPS receiver and a modulating radio transmitter. The function of the base station is to send correction data of GPS position to each crane station. 2). Each crane
21、 will be equipped with a GPS rover station which consists of two GPS receivers and a common radio receiver. This rover station will check the current position of the RTG with a precision at centimeter level. The position signal will be sent to the main PC to be dealt with for functions of container position and auto steering control etc. The whole GPS system is compact, simple and independent and it is easy to be 1nstalled on RTG without imposing any influence on the mechanical design.
