“…Similar to autonomous vehicles, ETAs use a set of sensing -e.g., ultrasonic, infrared, radio frequency identification (RFID), and global positioning systems (GPS) -and visual technologies -e.g., stereo and RGB-D cameras -to perceive the environment, detect objects, and process the information [11], [13]- [15]. This process must be executed in real-time, under diverse and unknown environmental conditions, and be safe to the users [16].…”