Study On Advanced Public Transportation Information System Based On Station Beaconing

Advanced Public Transportation system (APTS) technology was a significant part of Intelligent Transportation System (ITS). The APTS system was developed as the important application system of ITS in many countries. In China, its development was especially concerned. This paper presents a novel technology of APTS system. It combines with the short radio frequency (RF) communication technology and General Packet Radio Service (GPRS) wireless transmission technology.In this paper, first overall scheme and flow of system was designed which based on the technical realization mode of APTS system. Function and interface types of main modules composing system hardware were analyzed. Secongly according to function requirement of APTS system, the hardware system was developed and designed. It was composed of two parts:On Board Unit (OBU) and Road Side Unit (RSU) which both were consisted of GPRS transmission module and short distance wireless positioning module of radio frequency. Aiming at vehicle location error, odometer cumulate error correction technique based on beaconing fixed-point was analyzed. The theory of correction reference point selected based on RSSI was also researched. And the beaconing positioning correction algorithm was designed. It was proved that this algorithm was feasible by the experimental data. Then according to the functions of hardware devices in the system, the communication software was designed and developed where GPRS and short distance RF were as transmission technology. The functions such as automatic positioning; error correction; wireless data transmission and vehicle real-time monitor were achieved.Finally, every function modules of APTS system were tested. And the feasibility of the designed APTS system was verified by the test results.