Design And Study Of Melting Ice Process In Car Window And Detection System

Melting ice performance of car windows is of great importance for safe drive. Now, most of melting ice use air-conditioning system. The most common way to assess performance of melting ice using air-conditioning is that using transparent paper to describe the melting ice layer boundary, then compute the area that boundary rounds. This method has low efficiency and bad real-timeliness. As a new-style testing tectonic machine vision of faster speed, higher precision and non-contact testing available, it does well in conquering deficiency on manual work and improving both automate and efficiency.First, do a simple introduction for the development of the topic at home and abroad and the need for Monitoring melting ice of windows. Traditional design of the defrost outlet and duct mainly bases on experience. This method has many deficiencies. Using computational fluid dynamics (CFD) numerical simulation analysis, can make mathematical models instead of the traditional defrost test and the simulation test study, greatly shorten the development cycle, and reduce profligacy in time and money for the trial. After the theoretical design using the design of the products also need experimental testing to assess the performance of the product design. So Deng yong-mei use a CCD detection system which can recorded hand-drawn graphics in real time track and determine the boundary surrounding area. Light pen and positioning accuracy can reach the order of 10 microns. Deng bao-qin proposed a measure system to meet certain requirements of speed and accuracy of automatic detection, the system base on local threshold selection method.Secondly, this article uses number simulation base on CFD to analysis characters of melting ice performance in theory. CFD is a discipline which rapidly rises since 20th century. CFD numerical method contains finite difference method, finite element method, boundary element method and the finite analysis method. FLUENT is computer software for simulation of a complex shape fluid flow and heat transfer in the United States, the core of FLUENT is solving module. In the module, the mathematical model is mainly based on the module Navier-Stokes equations and energy equation-based, meanwhile, it also contain Various turbulence models, multiphase flow model, combustion and chemical reaction flow model, free surface model, the melting/solidification model and the non-Newtonian fluid model and so on. The accuracy and stability are superior to the traditional programming with finite difference method. User simply select the appropriate model, define the appropriate boundary conditions, according to a number of defined conditions, such as solving the control of the convergence conditions, availability of the required accuracy of the solution. The third, Describes the part of machine vision in the principle of optical imaging, including the principle of imaging cameras, CCD image acquisition card works. Also, make a detailed description of design on the car window glass melting ice monitoring system. It also Introduce the system camera devices, imaging lens and image acquisition card selection and general workflow of the software system.Lastly, aiming at monitoring, this paper particularly researches the design of the Monitoring System of ice melting and image processing calculating arithmetic. After learning common image processing methods and analyzing characteristic of ice melting image, we make a particular study of the image Enhancement, segmentation and smoothing.The tests demonstrate that this system perfectly match experiment of melting ice on car windows.