Millimeter-wave radar (MMW radar) and LiDAR are both used in automotive sensing systems, but they have distinct differences in working principles, capabilities, and applications.
Working Principle
Millimeter-Wave Radar (MMW Radar): Uses radio waves in the millimeter-wave frequency range (typically 24 GHz, 77 GHz, or 79 GHz) to detect objects by measuring the time delay and Doppler shift of reflected signals.
LiDAR (Light Detection and Ranging): Uses laser beams (usually in the near-infrared spectrum) to scan the surroundings and create a high-resolution 3D map by measuring the time it takes for light to return after hitting an object.
Detection Range and Accuracy
MMW Radar: Has a long detection range (up to 250m), performs well in adverse weather conditions (rain, fog, dust), but has lower resolution and struggles with small objects.
LiDAR: Provides high-resolution 3D imaging with precise object detection and shape recognition but has a shorter range (typically 100-200m) and can be affected by harsh weather and strong sunlight.
Application in Cars
MMW Radar: Commonly used for Adaptive Cruise Control (ACC), Blind Spot Detection (BSD), and Collision Avoidance systems.
LiDAR: Mainly used for autonomous driving and advanced driver-assistance systems (ADAS) due to its detailed environmental mapping capabilities.
Cost and Complexity
MMW Radar: More cost-effective, compact, and widely adopted in production vehicles.
LiDAR: More expensive and complex, but its prices are decreasing with advancements in technology.
In summary, MMW radar is better for long-range detection and operation in all weather conditions, while LiDAR provides superior resolution and object recognition, making it ideal for high-level autonomous driving applications.
