A Design Of Sling State Monitoring System By Embedded With Image

Hoisting-machine is a large-scale mechanical device usually used in the field of engineering,for hoisting and releasing weights.Its safety directly relates to the safety of the entire workplace.Due to incorrect operations of hoisting-machine,such as side pulling,shaking and etc.,the angle between the wire ropes and the plumb line may exceed the limitation so that the wire ropes may wear out and high potential risk may exist.Thus,a real-time monitoring system watching the wire ropes can warn the operators to correct their operations,when the angle exceeds the limitation.It will reduce the cost of maintenance and improve safe service time of machine.This paper concerns the monitoring system of the wire rope's offset angle.Based on embedded micro-control unit(MCU)and micro-image capture device,the monitoring system can catch the image of the wire rope during its swing and calculate the rope swing angle offset to the vertical after image identifying and processing.In order to realize the monitoring system,this paper mainly completed the following work:Firstly,this paper analyses the requirements of the monitoring system and proposes a embedded solution based on the wire rope's image.The functions of image acquisition module,image processing unit,alarm unit and their connection in the monitoring system are specified so that the overall design of the monitoring system is realized.Secondly,for the image capturing unit,this paper analyses the composition and the internal relation of camera and MCU,and gives the image acquisition function with STM32F4 series MCU and OV series camera.Thirdly,for the problem of image recognition and processing of the wire rope,this paper gives the recognition method by a series of pre-processing algorithm such as gray,smooth,edge detection,Hough transformation.It shows the relationship between the actual rope offset angle and the offset angle in the image based on the lens image formation rule.Finally,it uses STM32F407 MCU,OV7670 camera,LCD display,and a buzzer to set up a prototype monitoring system.Several experiments are carried out to monitor the wire rope's offset angle and verify the algorithms on image processing and angle calculating.