Design And Development Of Elevator Fault Alarm And Diagnistic Unit Based On Wireless Network

By analyzing the application status and the development trend of wirelesscommunication and fault diagnosis technology used in elevator field, it is proposed anelevator fault alarm and diagnostic unit based on wireless network such as GPRS andWi-Fi that has functions of data acquisition, fault alarm, remote wireless datatransmission, fault diagnosis and repair service. This paper focused on design anddevelopment of GPRS-based fault alarm, Wi-Fi-based wireless data transmission andexpert system-based elevator fault diagnosis.Firstly, after putting forward overall program and structure of the elevator faultalarm and diagnosis system, core CPU, embedded operating system, functionalmodule and structure of application software was determined. Focus on hardwaredesign, which include the design of core board and expansion board, of the unit. Coreboard, including modules as Flash, SDRAM, clock and expansion interface, wasdesigned with the conception of minimal system, which used S3C2440as coreprocessor. Expansion board had functional modules as serial port of debugging, GPRS,voice chip, Wi-Fi, LCD touch screen, USB interface, SD card interface, Ethernet port,JTAG and reset circuit. At last, WinCE6.0was chosen as the embedded operationsystem.Then, this paper focused on the design and implementation of the applicationsoftware of wireless alarm and communication. After describing the superiority ofGPRS and Wi-Fi, program flow of GPRS-based alarm and Wi-Fi-based transmissionwas designed. Then, this paper focuses on the achievement of alarm and transferprograms by the use of embedded Visual C++language.Finally, elevator fault diagnosis based on expert system was achieved. Byanalyzing the advantages of theory of expert system and fault tree, this paper firstlyestablished the elevator fault tree model, from which extracted expert rules. Secondly,knowledge base and forward inference engine for expert system was designed. Then,this paper used SQLite database for management of knowledge base. Finally, by usingembedded Visual C++, diagnosis function was achieved. In addition, this paper alsorealized service functions such as inquiry of elevator information and registration ofservice information.