3D-Sensing MIMO Radar for UAV Formation Flight and Obstacle Avoidance.

This paper presents a millimeter-wave (mmW), multiple-input, multiple-output (MIMO) radar capable of three-dimensional (3D) sensing for applications in UAV formation flight (FF) and obstacle avoidance (OA). The radar consists of a custom, 3D-sensing, MIMO antenna array integrated with a commercial automotive radar. The antenna array is optimized for FF and OA. Specifically, the antenna is designed for wide scan range in azimuth while sacrificing scan range in elevation. This tradeoff reduces the complexity, size, weight, and power of the radar while maintaining sufficient coverage of 3D space for nearby obstacles and UAV peers, which are often arranged in a common azimuthal plane for FF. Experimental results are provided which verify the 3Dsensing capability of the radar against a small peer/obstacle drone hovering at various prescribed aerial locations. The standard deviation of the position estimation is 0.61° in azimuth, 2.6° in elevation, and 0.13 meters in range.