Research And Design Of Augmented Reality Head-Up Display Optical System For Vehicles

With the improvement of people's living standard,the number of road motor vehicles per capita has been growing every year.The importance of driving safety should be stressed even more.Augmented Reality Head-Up Display can present the driving speeds,navigation,and other information more intuitively and more effectively,ensuring that the driver's line of sight does not leave the road surface,preventing the blind area of driving vision.In this way,the driving safety is improved.Three aspects of research,focusing on Head-Up Display for Vehicles and its combination with Augmented Reality technology,are presented in this thesis:1.This thesis introduced the relevant theoretical basis of the Head-Up Display system.Firstly,we analyzed several common structures and the mainstream developing trend of the HUD system.Secondly,we focused on the windshield integrated HUD system and introduced its system composition and parameter specifications requirement:At first,we analyzed the four image source systems that widely used in the HUD system,giving their respective advantages and disadvantages.Then,we presented the solution of the angle of the simplified wedge-shaped laminated glass,and the freeform surface used in the HUD system.Finally,the performance parameter specifications of the HUD system were formulated both in traditional HUD and AR-HUD,according to the actual user needs.2.This thesis accomplished the optical design of a traditional HUD system,which built the base of AR-HUD design.Starting from the actual parameter specifications,we calculated the specifications for back-lighted illumination.Then,the lateral folding layout was determined under the spatial limitation,and the initial structure was arranged by adopting the reversed design method.After that,the design result was given and was evaluated from four aspects:Footprint,Spot Diagram,Grid Distortion,and Modulation Transfer Function.Next,we discussed the influence of replacing the 5th order XY polynomial freeform with aspheric surface or XY polynomial freeform that is lower than 5th order.Finally,the processing of the traditional HUD prototype was introduced,and the virtual image projection result was demonstrated.The image is clear,and the distortion is small,which verified the feasibility of the design.3.This thesis realized the optical design of the augmented reality head-up display system.The main design method is to make use of more optimization variables of those two freeform surfaces to correct the severer aberrations and distortions.Firstly,the longitudinal folding was determined as the final spatial layout and the spatial structure was arranged.Then,specific optimization strategies were analyzed.After that,the design result was given and evaluated from the same four aspects:Footprint,Spot Diagram,Grid Distortion,and Modulation Transfer Function.Next,the influence of replacing one of the two XY polynomial freeform surfaces with a plane mirror was discussed,showing single XY polynomial freeform is not suitable for AR-HUD system.Then,the influence of moving the major freeform reflector was also discussed.The experimental setup and display results of the AR-HUD prototype were demonstrated,which proves that the system meets the hardware requirements of the augmented reality technology.Finally,the limitation of the reflective HUD system was analyzed.