The Research Of Anti-tow Accident Video Curtain In Elevator System

With the widespread use of the elevators, there are some new accidents nowadays. Itwas an accident that a little boy’s finger might be towed by the sightseeing lift, andsandwiched between the landing door and the doorpost, when it was opening. Inresponse to this phenomenon, there ware many solutions. For example, mount therubber blanket in the door to reduce gap, install the ultrasonic elevator door detector,assembling an anti-clamp safety device in the lift system, etc. However, there are allseparate types of device.The anti-tow video curtain contained a camera, which was assembled on the topof the elevator car door to monitor an appropriate outside area of it. The elevator gateto turn on or off was controlled by the data processing result of digital image signal,which was collected by the camera. It mainly used microprocessor to dispose thecollecting date, and this also meant detection and velocity calculation of the movingobjects. The results ware compared with the predetermined threshold to judge theexistence or inexistence of tow accident. If the date was in the threshold, there was atow accident. The elevator main controller received the signal sending bymicroprocessor, then paused the opening door to prevent accidents.This thesis was based on analysis of image processing technology, and processingvideo date by the software programming on PC platform. How to gain streamingvideo date from the camera by DirectShow was studied. In allusion to the problem oftowing, frame-difference method was used to detect moving object in the targetspecific areas. Then improved SUSAN algorithm adapted to process it, and get theextract target pixel. The results ware compared with the predetermined threshold tojudge the existence or inexistence of tow accident. Efficiency was improved by the use of improved frame-difference method and SUSAN algorithm.The anti-tow video curtain in elevator system took a new design, introducing theimage processing technology to safe detection device, and to test the moving object,which was towed by landing door, when the elevator door was opening. Finally,achieve to prevent accidents. In the actual environment, debug the program repeatedlyto draw the most suitable threshold. Not only ensured accurate detection of target, butalso was the normal operation of the elevator not impact.The video-based anti-tow curtain in elevator system is not only accurate detection,but also strong valuable in use. On this basis, it could be used in the automatic doorsof the subway, office buildings and other systems through slightly modify. It has avery broad prospect.