| Strong light exposure affects driving safety and riding experience,therefore,cars are equipped with sunshades.However,traditional sunshades usually have the following three disadvantages: firstly,they need to be manually reversed,which diverts the driver’s attention during operation and affects driving safety;secondly,they are usually made of opaque material,which blocks the view while blocking light and further affects driving safety;thirdly,sunshades are usually installed only on the main driver’s seat,so the strong light from side windows and sunroofs cannot be blocked,which affects the comfort of the ride.As traditional sun visors have many drawbacks and are less practical,this paper replaces the traditional car sun visor,side windows and sunroofs with a dimming glass that can be flexibly adjusted for light transmission.The dimming glass is designed to reduce the light transmission as the voltage increases,allowing flexible control of the light intensity in the cabin and improving ride comfort.It automatically blocks out strong light while retaining a certain level of light transmission,eliminating the need for manual operation and extending the driver’s field of vision to improve driving safety.The main research elements are as follows:(1)An overview of the current development status of traditional sunshades and dimming sunshades at home and abroad.The dimming materials currently available on the market are categorised into three types: Polymer Dispersive Liquid Crystal(PDLC),Electrochromic(EC)and Suspended Particle(SPD),and their light changing principles are studied and the characteristics of the three materials are summarised,with analysis and selection based on actual needs.(2)Control circuits are designed according to the working characteristics of the dimming materials.The new dimming materials use 0V-10 V AC power supply,while only 12 V or24V DC power is usually provided in the car cab.Therefore,the first design hardware circuit will be a car cab 12 V DC power into a 0V-10 V range of several different gears of square wave AC power,so that the dimming glass with multiple shading gears.In addition to the voltage conversion function,the hardware circuit also needs to have a key function module,a light detection module and a communication module.(3)Based on the actual requirements of the control circuit,the control programme is designed.Firstly,the light sensor is used to detect the light intensity in the cab and adjust the light transmission of the vario glass in real time according to the light intensity to realise the automatic light blocking function.Then the manual adjustment function is designed according to the physical button,supporting the automatic shading mode/manual adjustment mode conversion and the control of the shading position.Finally,the communication module program design is completed to complete the data communication function with the subsequent control APP.(4)The intelligent cockpit software architecture in China is reviewed,and the control APP is designed according to the current intelligent cockpit mainstream architecture system,and the relevant program is designed to complete the data transmission function with the communication module of the control circuit,and to control the dimming mode and dimming position increase/decrease function of each sunshade in the cab.In addition,to verify the suitability of the preset automatic dimming positions,data is collected from the user in manual adjustment mode.The STS authentication application server is built according to the above requirements to respond to the control APP access and return the Security Token with Aliyun OSS write permission.(5)The reliability analysis of the designed control circuit is carried out and verified on the real vehicle.Firstly,its theoretical mean trouble-free operating time was calculated to verify its commercial possibility.The sunshade sample and its control circuit are then tested in a real vehicle installation and the test results are given. |
PDF Full Text Request