Optimization And Research Of Elevator Information Collection And Micro-projection System Based On ARM

In recent years,the number of elevators in China has increased rapidly year after year,which reflects that elevators are playing an increasingly important role in modern life.Elevators have become one of the most frequent places every day.Therefore,how to ensure the stable operation and safety of elevators and improve the environment has become one of the hot issues of social concern.The safe and stable operation of the elevator is the most important thing.Through real-time monitoring of elevator operation status and collection of elevator operation information,elevator faults can be predicted in advance based on big data analysis to avoid potential safety hazards.At the same time,because the interior of the elevator is a relatively closed and narrow space,passengers may face various unexpected situations.It is the inevitable development trend of elevator safety prevention for timely and accurate identification of abnormal behaviors of passengers.In addition,the existing elevator multimedia display system has small images,single playing content,which is inconvenience for passengers.What’s more,it is prone to irritability and depression in a narrow elevator space,resulting in poor experience.Therefor,this paper proposes the optimization and research of elevator information collection and micro-projection system based on ARM embedded system,and mainly discusses and studies an independent system implementation method integrating elevator operation information collection,passenger abnormal behavior identification and projection display of multimedia information.According to the design requirements,the concept of edge computing is introduced,and three edge computing devices are allocated and deployed to ensure the computing power requirements of each module of the system.In the part of elevator operation information collection,firstly,JY901 B ten-axis high-precision sensor is proposed to detect the acceleration and atmospheric pressure of the elevator,and PT100 resistive sensor is used to realize wide-range temperature measurement inside the elevator.Then,the relevant hardware detection circuit is designed and completed to realize the independent collection of elevator information.It does not need to rely on the elevator’s own control system or install other auxiliary calibration equipment,which is suitable for the installation of new elevators and the upgrading of old elevators.Finally,improve the air pressure-altitude conversion algorithm by using the collected acceleration,air pressure value and temperature value,propose elevator start and stop detection algorithm,floor identification algorithm,adaptive calibration algorithm and segmented temperature compensation algorithm,and complete the real-time data detection and acquisition of elevator running acceleration,average speed,up and down state,running floor and internal ambient temperature parameters.The experimental results show that the elevator information acquisition system proposed in this paper can accurately detect the elevator running state,in which the elevator state and floor recognition rate reach 100%,and the temperature measurement accuracy reaches ± 0.1℃.In the part of elevator passenger abnormal behavior detection,this paper proposes a three-level cascade convolution neural network architecture,which completes model training through self-built elevator passenger abnormal behavior data.The three-level convolution neural network model can accurately identify abnormal behaviors such as passenger falls,syncope,fights,group fights,etc.Considering the limited computing power of edge computing devices,this paper proposes a method to collect real-time passenger behavior video data through edge computing devices and embed it into Web server.Then the video data is accessed in the background server to identify the passenger behavior,and the abnormal behavior is returned to the coordinates of the target detection frame.Drawing in the video frame in the edge computing device,switching the projection display method to achieve the warning and reminding function.The experimental results show that the classification and recognition accuracy of the three-stage cascade network proposed in this paper can reach 94% and 89.4% in the actual test of passengers’ abnormal behaviors inside the elevator,and the average time from identifying abnormal behaviors to switching projection display is 1.7 s.In the part of elevator multimedia display,this paper proposes an optimization scheme to replace the traditional LCD screen display method with a micro-projection optical machine.The micro-projection system projects the picture on the upper 1/3 of the elevator door with large projection picture and rich projection content.In this module,the hardware system of the micro-projection system is built and completed.The projection interface design is completed through QT programming,and the collected elevator information is displayed synchronously and visually,which makes up for the deficiency of traditional multimedia.In addition,a mobile phone APP is designed and developed for updating the playing content of the micro-projection system,which realizes updating the multimedia content wirelessly.In order to ensure the power supply stability of each module of the system,+12V stabilized power input is designed.Through multi-channel DC-DC conversion circuit based on LM2596 step-down voltage,each module is supplied with power separately,and the standby power supply charging and discharging circuit is designed and implemented to realize stable and uninterrupted power operation of the system.Then,the hardware circuits of each module of the whole system are integrated and designed in a PCB board to realize the simplified design of the whole equipment structure.Finally,through the integration of each module of the system,the prototype of elevator information collection and micro-projection system based on ARM embedded system is completed.Installed in many places,multiple elevators internal field for operation test.Through repeated optimization and adjustment problems,the final experimental results show that the research in this paper meets the expected design requirements,can accurately detect the elevator operation information,and timely identify the abnormal behavior of elevator passengers.The projection picture of the micro-projection system is clear and the projection content is rich,which improves the elevator comfort.