Microwave Radars for Automotive In-Cabin Detection

Modern cars are complex systems where the passenger safety and comfort are high on the list of the requirements. To this aim, the chance to control the car infotainment system without any contacts represents an advanced feature with a great potential in different applications. In this contribution, a 24 GHz Doppler radar system was specifically designed to investigate the features and current challenges related to the in-cabin detection topic and in detail concerning the radar capability to control the touch-free infotainment system. A case study concerning the contactless adjustment of the car audio system was demonstrated first by identifying the right gesture by exploiting the micro-Doppler analysis and subsequently by extracting the desired volume level from the real fingers’ aperture. To measure the fingers’ aperture, the radar feature to detect movements in the range of millimeters and below was exploited. Moreover, the phase and amplitude imbalance between the two receiving channels was estimated and corrected. Exploiting radars to enable such a kind of features might pave the way to the next generation of advanced cars where the passengers will be able to comfortably control different infotainment systems.