SPRY346 March   2022 AWR1843 , AWR1843AOP , AWR2243 , AWR2944

 

  1.   At a glance
  2.   Authors
  3.   Introduction
  4.   Advancing from 24-GHz to 77-GHz radar for mid- and short-range applications
  5.   Imaging radar vs. lidar
  6.   Expanding radar to new applications
  7.   Radar for ultra-short-range applications
  8.   Driver monitoring for ADAS
  9.   Conclusion

Radar for ultra-short-range applications

Today, surround-view cameras and ultrasonic sensors enable parking assistance. Drivers are still required to make judgments and maneuver based on sensor feedback, however. Plus, in severe weather conditions these sensing modalities cannot work independently; thus, the cars are not completely autonomous.

To enable automated parking functionality, the sensor should be capable of detecting other cars, curbs or pedestrians from 3 cm to more than 40 m away in a wide field of view, in any kind of environmental conditions. mmWave sensors help achieve this functionality by accurately detecting smaller objects (such as a metal rod protruding from the ground) that other sensing modalities may not be able to detect from a distance less than 25 cm, all while functioning under a variety of weather and lighting conditions. Radar sensors also improve the overall aesthetics of vehicles because they operate behind the bumper and do not require any drilling of holes on bumpers.

The AWR1843AOP provides a wide field of view in both azimuth and elevation that enables true 3D detection for various objects. A wide field-of-view with the integrated antenna makes it possible to achieve 360° coverage with a minimal number of sensors, as shown in Figure 5.

Figure 5 Comparison of range and field of view for ultrasonic vs. mmWave radar systems.

A mmWave radar sensor’s 77-GHz bandwidth enables high range resolution so that it can distinguish between various types of objects across a wide field of view, including wood, metal and plastic, as shown in Figure 6.

GUID-20220302-SS0I-GGFT-SVZR-6SQVNQSHQDFN-low.png Figure 6 Multiple types of objects detected by a mmWave radar sensor.