Special Section on Human Centric AR&VR Display and Human Interface Technologies for Automobile Figure 4. Activity diagram showing HMI behaviors related to interactions with the ADS and other constituent systems. with any external systems, which can enhance the driver's understanding of what is occurring around the vehicle. This function simultaneously initiates the functions "guide driver behavior" and "inform of driver's state," but the latter function is executed only when the driver is not in a sufficient state to recover vehicle control. The latter function shows the driver's current state and may call the driver's attention to prepare to regain control of the vehicle. The former function shows what action the driver should take to regain control of the vehicle. This function can enhance a driver's understanding of the differences between the behavior to be implemented by the driver and the desired driver behavior proposed by the ADS. building the hardware and software and was used to build the verification environment with a driving simulator. The graphic contents and display timing of the HMI visual display is an implementation of the HMI inner functioning (Figure 5). These contents will be verified to be appropriate using the driving simulator to confirm that the HMI requirements (Figure 3) has been fulfilled. Figure 6 shows the contents of the HMI visual display, which are designed to enhance a driver's understanding of information regarding VERIFICATION-DRIVING SIMULATOR WITH HMI DISPLAY A driving simulator in which a visual display was implemented as a cluster in the block of the HMI was used as a verification system. The HMI functional flow (Figure 4) was utilized as a test case used for verification because the system model describes the desired behavior of the driver, ADS, and external systems, which interact with the HMI. The test case was used to check the input/output, operating conditions, and expected results of each system prior to 96 Figure 5. Functional flow of the HMI inner functioning. IEEE Consumer Electronics Magazine