Research And Reliability Analysis Of Elevator Door Failure Early Alarm System Based On Single Chip Microcomputer

The elevator is a kind of electromechanical vehicle that is often used in people’s life.However,the elevator accidents happen in the nationalwide every year.The function of existing elevator emergency rescue system has yet to be improved,and the failure monitoring system highlighted in these problems for having a poor compatibility,a high price,especially there is still exist a shortage in the prevention of elevator accidents of tipping off.To design a kind of elevator door failure monitoring and warning system which has a set of functions such as accident prevention,failure warning and condition monitoring,and has advantages of strong universality,practical function and being cheap.It is of great significance to improve the safety level of elevator,which can effectively reduce elevator casualties and property damage.In designing an elevator door failure monitoring and early warning system prototype in this paper,the author has carried out such work for ultrasonic ranging circit,early warning system prototype development,host computer interface monitoring and reliability analysis.The main contents and conclusions are as follows:(1)Distance sensing prototype design scheme of early warning system for elevator door failure based on Single Chip Microcomputer.The reasons in the failure of the elevator door system are analyzed in depth,and the failure condition combination of the elevator door system is summarized.The method based on the temperature compensation is adopted in the distance detection,and the experiment is showed that the effective measurement distance is30 cm to 450 cm and the error of the ranging circuit is less than 1cm,the method can meet the requirements of the elevator door failure detection and warning in measure accuracy and range.(2)Hardware and software design of four-channel ultrasonic distance measurement early warning system.Producing the PCB board by using the AD9 circuit software and then welding hardware module,then doing the software design by using the Keil uVision4.The simple experiment proves that it can effectively realize the warning in the event of the elevator door failure.At the same time the elevator door failure monitoring and early warning host computer interface design was carried out by using the labVIEW software.The interface design by using the Single Chip Microcomputer as the control core and by using the serialport to realize the real-time communication with the PC,and it can be applied to remote monitoring and early warning.(3)System circuit reliability analysis.The complex network theory is used as the theoretical basis of the circuit reliability analysis,the circuit components are equivalent to the nodes,the weighted network model based on the component failure rate is established for the circuit of the distance detection early warning system.The center parameters of the network are calculated and analyzed by using the Pajek software,the key components of the system circuit are clarified as U1,U2,C3,VCC and GND;using the Matlab to prepare matrix processing algorithm to get the network efficiency value,it can analyze the effect of the component failure rate on the reliability of the system circuit,The U1,U2 and C3 are extremely critical components,and it is also concluded that the components B1-B4 and L1-L4 have a great influence on the system reliability.The reliability analysis of the system circuit is completed from the angle of the combination of the circuit network topology and the component failure rate,which provides important reference value for the reliability design of the system circuit.