Research And Design Of Intelligent Road Marking Equipment Control System

In recent years,the rapid economic development has promoted the development of transportation roads,and the country's investment in road construction has continued to rise,while also promoting the development of the road maintenance industry.As an important part of road maintenance,road marking work becomes very heavy and faces huge challenges.At present,China's road marking equipment has a low degree of automation.It is mainly based on manual hand-pushing simple marking machines and rack-mounting marking machines,which is inefficient and can not be sprayed according to actual needs.Moreover,the accuracy of the existing marking machine depends on the operating experience and technical level of the workers,and subjective factors have a great influence.Therefore,researching and designing an intelligent road marking machine that can spray road markings and characters is of great significance to promote the upgrading of the road marking industry and meet market demand.In this paper,ARM and image processing technology are combined to study and design a road marking machine control system with automatic spraying and automatic positioning functions,including spraying module control,nozzle positioning and marking machine motion control.The nozzle part adopts single-row array nozzle,multiple nozzles are arranged at equal intervals,and is connected to the solenoid valve.Through the opening and closing of the solenoid valve,different nozzles are controlled to spray the marking paint to meet the spraying requirements of road marking.The hardware part introduces the composition and functions of the marking machine control system,including the STM32F103VET6 controller and its minimum system,video acquisition module,host computer communication module,spraying module and travel module,and gives the corresponding circuit design.The control program of the spraying module is divided into two parts: calling and processing.First read the dot matrix address and spray parameters of the characters and graphics to be sprayed from the storage module,extract the corresponding dot matrix data from the designed font according to the dot matrix address,and put it into the cache array.Then,the nozzle module drives the solenoid valve to open or close at different positions through PWM modulation,so as to spray out the selected characters or marking lines.The location of the nozzle depends on the position of the marking machine,so it is necessary to control the movement of the marking machine.When the road marking device is traveling,the longitudinal position is determined by the encoder,and the lateral position is obtained by image processing.The acquisition of lateral position parameters mainly includes three stages: image preprocessing,road edge line detection and extraction,positioning andcontrol decision.In the image pre-processing stage,the road information is collected by the camera and uploaded to the host computer for graying,filtering and threshold segmentation to distinguish the road from the background;the road edge line is detected and extracted using Canny algorithm and Hough transform Combined with the imaging rules of the camera,the road reconstruction from the two-dimensional road image to the three-dimensional space is performed,and the position parameters are calculated in real time,thereby controlling the driving and movement of the marking machine.Finally,the control system of road marking machine is verified by experiment.The results show that the intelligent road marking equipment can identify and extract the road edge information under various road conditions,determine the location parameters,and spray out relatively complete markings and graphics.