A more recent focus on driver comfort and the increasing demand for wide range of information availability make automotive Original Equipment Manufacturers (OEMs) provide advanced features such as Head Up Display (HUD) system. Even though HUD projects vital information onto the windshield/glass, its structural integration comes with significant vibration challenges, leading to display instability and haziness. This paper discusses the significant design parameters influencing the functional effectiveness of HUD system. The structure considered for analysis is the HUD assembly and its integration in vehicle. Cross Car Beam (CCB) turns out to be the critical component of the vehicle structure susceptible to road excitations. Although it’s mass dampens the vibrations inherently, due to the low mass of the HUD, relative oscillation between its projector, mirror, and either the windshield or display causes image distortion
This paper investigates in detail the role of HUD structural stiffness, eccentric design and material of the display glass and its shaft in achieving optimal HUD functional performance of high definition display. Based on this analysis, the system natural frequency has to be above a particular frequency called Critical Flickering Frequency (CFF) to avoid fuzzy image perception to human eyes . CFF for the HUD discussed is calculated using a structured and controlled subjective study taking care of all the significant parameters affecting it with individuals from all ages and gender. This data is used to build a robust design criteria for the HUD structure for a highly stable display.
This research including the novel approach of integrating the concept of CFF in display system vibration development in particular is of significant value to automotive engineers in designing robust functional HUD systems. Addressing the above critical design parameters, this paper paves the way for a seamless in display experience in modern connected vehicles.