Development Of Multi-function Dynamic Visual Acuity Testing And Training Device

In recent years,with the rapid development of China’s transportation industry andthe number of private cars massive growth, forcing the occupants to face morecomplex traffic environment, therefore, the driver’s driving skills has been anunprecedented challenge. Some traffic developed countries have the dynamic visualacuity into the motor vehicle driver qualification examination. And dynamic visualacuity has a direct impact on the competitive level of athletes and the quality ofspecial tasks of pilots. Therefore, to achieve the popularization of dynamic visualacuity’s test has great social significance. The main purpose of this paper is to build amulti-functional dynamic visual acuity testing and training system, the ultimate goalis to solve driver’s dynamic visual acuity testing problem.According to the testing of DVA dynamic visual acuity and KVA dynamic visualacuity, this paper completes the development of a multi-function dynamic visualacuity testing and training device. The whole device’s difficulty is the dynamic visualmark’s design and generation, glare to simulate the actual environment, the design andimplementation of peripheral hardware, the PC software system development, eyemovement monitoring part of the eye image acquisition and the pupil recognitionbased on Hough transform.In dynamic visual mark’s design and generation, this paper based on the objectimaging and one points perspective theory, analyses the relationship of “C” and “E”mark’s opening direction and perspective’s size.Using “C” mark as dynamic visualacuity test’s standard mark, and through “C” mark’s perspective to calculate thecorresponding value of dynamic visual acuity. In dynamic visual acuity test, openingof the mark has eight directions. When generated the mark in software, we mustspecify the mark’s appears way, and using the random number theory to achieve theappears of mark with randomly direction. So we are unable to determine the nextmark’s direction. In addition, this paper also according to the difference of DVAdynamic acuity and KVA dynamic acuity, respectively specify the DVA and KVAdynamic mark’s generation strategy.In this paper,the glare’s composition is LED lamp assembly with different color,distribution around the mark display to simulating the real environment. In order toguarantee the stability of the glare intensity, this paper realizes the glare calibrationbased on the glare’s theory. The SCM controls of peripheral hardware part, the main control module, the handle control module and the glare control module realizesone-on-one communication with PC software. In order to study the change regularityof eye pupil in observation, the device is provided with eye movement monitoringmodule for image acquisition and recognition of the eye pupil. Using VC4000acquisition card to collect images on the camera, and the acquisition program isimplemented by VC++and OpenCV programming. Using Hough transform toidentify the pupil, first on the gray image preprocessing, and then edge detectionbased on Canny operator, edge detection using adaptive median filter to replace Gausssmoothing, using Hough transform to connect the pupil edge.Based on research on basic structure of dynamic visual acuity testing device andprinciple, combined with the system testing process, the communication processbetween PC software and the SCM control modules, software’s function and dataanalysis ans management to formulate the PC software’s overall architecture ofmultifunction visual acuity testing and training device and realize the design andimplementation of PC software. The software is developed with VC++6.0MFC.According to different landing permissions to enter the different interface and toachieve different functions. Testers can realize the two kinds of dynamic visual acuitytesting and training by the operation of the software. The background can evaluate theresults reasonably according to different groups. The device adopts the Accessdatabase for data storage and management, having powerful data processing ability. Inaddition, the device is joined with the norm analysis and we can get norm analysisaccording to different testers.