Spatial-Diversity Radar With Ground Effect Compensation for Vehicle Collision Warning Applications
|關鍵字:||空間多樣性;連續頻率調變雷達;spatial diversity;FMCW radar|
This dissertation discusses a realistic road surface can cause multipath reflection, degrade the received power, and reduce detection probability for automotive radar application. A one-transmitter-two-receiver (1T2R) frequency-modulation continuous-wave (FMCW) radar architecture with spatial diversity and ground-effect compensation for automotive applications has been proposed. Besides, several vehicle collision warning radars have been developed and implemented for automotive applications. In the first stage of this dissertation, several techniques to acquire data and recognize as a target have been introduced and discussed, especially for automotive radar application. The focus is on waveform design in general and on automotive applications in particular. Target detection is an important issue for all radar systems. Therefore some Constant False Alarm Rate (CFAR) procedures are discussed which can be applied, especially in multiple target situations, to avoid masking. Additionally some tracking techniques are introduced and discussed for target recognition which have been developed for automotive applications Next, the multipath reflection caused by a road surface has been presented. A four-ray model has been introduced to estimate the received power response with a ground surface by ray-tracing technique. The power responses of multi-reflection with ground surface at 24 and 77 GHz have been investigated and discussed, which reveal the road surface leads severe power degeneration. Moreover, a Sallen-Key high pass filter has been introduced to compensate the path loss of the received power response. Based on the knowledge of multipath effect of a road surface, we further proposes a one-transmitter-two-receiver frequency-modulation continuous-wave (FMCW) radar architecture with spatial diversity and ground-effect compensation for automotive applications. In the proposed design, suitable spacing between the two receiving antennas compensated for the multipath effect of the road surface and improved the signal-to-ground-clutter ratio of the receivers at certain distances. In the last part of the dissertation, a spatial-diversity 24-GHz radar has been proposed and implemented for forward-looking application. The measurement results show a good agreement with the calculated results, which largely increase the received power and detection rate. Besides, a compact 24-GHz blind spot detection (BSD) radar has been developed for a short range warning application referring to ISO 17387 specification, which provided a good protection in the blind zone for the driver. Moreover, a single-lane-cover 24-GHz radar has also been presented to provide a forward collision warning feature, and has the potential to be applied in the Autonomous Emergency Braking (AEB) system in the future. Finally, a high gain slot-pair substrate-integrated-waveguide (SIW) antenna has been presented as a candidate for the proposed spatial-diversity architecture for 77 GHz vehicle collision warning application.