Desigh And Implementation Of A Communication Terminal For Mobile Construction Machinery Based On Embedded Linux

It is an important precondition of clustered intelligentized construction machinery that implements sharing the information between mobile construction machinery and control center. And the study done by this thesis makes a great contribution to researches on"Clustered Intelligentized Construction Machinery", a National 863 project, in charge of Xuzhou Construction Machinery Group,Southeast University,Tsinghua University and Traffic Institutes Of Chongqing.This thesis first introduces the concept of"Clustered Intelligentized Construction Machinery"and its research status. And a detailed analysis is made on the information requirement called by construction environment and all kinds of construction machinery. According to these requirement and the different characteristics of construction machineries, this thesis respectively discusses different communication methods between different construction machineries and control center.The scheme based on embedded system has been chosen according to the characteristics of construction machinery. In the thesis, this scheme is proved, the device is designed and implemented, and the design of circuit boards for embedded GSM module, embedded GPS module and power supply module is completed. Then the mobile CAN/GPS/WLAN/GSM wireless communication terminal based on embedded Linux operation system, is finally implemented.By analyzes the characteristics of the working site, a wireless local area network is installed. Then the thesis shows how to write a wireless network communication program and makes a further study on the format of the CAN/GPS data to realize the collection of the status message from CAN bus and the GPS positioning information. All these data that acquired are finally transported as TCP data packet by WLAN and received by control center which stored them in database.This thesis also introduces two communication methods of wireless wide area network using on the terminal: one is based on SMS and the other is based on GPRS. As for SMS, all of the data, including CAN bus messages and GPS positioning information are assembled as parts of PDU, and was sent by GSM Modem using AT commands. As for GPRS, a network architecture is chosen,introduces PPP protocol and shows the implementation of GPRS communication on Linux. The differences between GPRS and SMS, mainly on traffic and rates are also analyzed by some experiments. Finally, the thesis studies the method to pass through firewalls and backward control of the communication terminal.