Sensor Fusion Architecture for Autonomous Driving
Autonomous and semi-autonomous driving requires the vehicle to perceive its environment accurately under all conditions. No single sensor technology provides complete, reliable perception β each has complementary strengths and weaknesses that motivate sensor fusion. Camera systems provide high-resolution color images and can recognize objects, read signs, and detect lane markings β they perform excellently in good light but degrade in rain, fog, glare, and darkness. Tesla's vision-only approach (FSD) relies on multiple high-resolution cameras with neural network processing, arguing that sufficient camera density combined with advanced AI can replicate human visual perception. LIDAR (Light Detection and Ranging) emits laser pulses and measures return time to create precise 3D point-cloud maps of the surrounding environment at up to 200-meter range. LIDAR provides accurate distance measurement and works in darkness but is degraded by precipitation (laser scatter) and is currently expensive ($500β$3,000 per unit, though declining). Waymo, Cruise, and most robotaxi companies use LIDAR as their primary sensor. RADAR uses millimeter-wave radio signals (77 GHz automotive standard) to measure distance and velocity of objects. RADAR is highly reliable in precipitation, fog, and darkness, and measures velocity directly (via Doppler effect) but provides low spatial resolution β it cannot identify object type clearly. RADAR excels at highway adaptive cruise control and is used in nearly all driver assistance systems. Ultrasonic sensors use sound waves for very short-range proximity detection (0β5 meters) β essential for parking, blind spot detection at low speed, and supplementary close-range awareness. The sensor fusion algorithm on the central compute platform (NVIDIA DRIVE, Qualcomm Snapdragon Ride) integrates all sensor data streams, resolving conflicts and maintaining a unified environmental model β detecting objects with higher confidence than any single sensor could alone.