Arrk Engineering, a development partner for the automotive and mobility industry, has partnered with test bench specialist Gefasoft to develop a new high-precision test bench designed to measure head-up displays (HUDs) in vehicles, with greater accuracy and automation.
The collaboration began in 2020, focusing on creating a test bench that could meet the strict specifications required for HUD systems. The test bench, which is designed to accommodate entire windshields, aims to permit manufacturer-independent measurements across various vehicle types.
The demand for comprehensive testing of HUDs has increased due to the challenges these systems present, such as difficulties in visibility under certain lighting conditions or the potential for distracting drivers if improperly calibrated. Traditional test benches often rely on outdated measurement methods, which do not meet the requirements of modern HUD technology. In response, the companies have developed a new system capable of conducting fully automated, precise measurements with a high degree of repeatability.
“HUDs are like any other technology: the more functionalities are mapped, the greater the demands on testing,” explained Sebastian Hensle, group manager of optical systems at Arrk Engineering. The new test enables the entire windshield to be measured, which is important for evaluating the latest HUD technologies.
“Especially in the context of new, larger HUDs or display content that is projected in the so-called black area of the windshield, for example, it is necessary to measure the entire windshield, which our previous test bench was simply unable to do,” he added.
The test bench is designed to be flexible and customizable, capable of adapting to future HUD generations. Gefasoft incorporated an automated conveyor line to improve the workflow for inserting new HUD projectors and designed a moveable windshield master that can be easily replaced. This flexibility is particularly important as future HUD technologies, such as augmented reality HUDs (AR HUDs), will use larger areas of the windshield for contact-analog projections.
The test bench also features photometric measurement capabilities, using a high-resolution LMK 6 color camera from TechnoTeam. The camera is guided by a linear system, achieving precise positioning accuracy, and the mechanical stability of the test bench ensures high measurement repeatability.
“We had to modify our software accordingly in order to realize the required test scope and measurement sequences,” said Jonathan Guthmann, project manager of vision/HUD at Gefasoft. “We also equipped the system with comprehensive access options and interfaces for our own extensions, so that our colleagues at Arrk Engineering can keep it state of the art in the future and adapt it to the challenges of new HUD generations.”
The fully automated nature of the test bench means lengthy tasks such as luminance measurements can be carried out without manual supervision.
“We chose Gefasoft as our project partner for two main reasons,” concluded Hensle. “First, because of their many years of expertise in the windshield and HUD sector and, second, because we were able to obtain hardware and software from a single provider.”
