The Sensors Automating Your Commute

In a bout of frustration I recently realized that the roads have all updated — most people have no idea how — and this sometimes hurts the flow of traffic. This realization happened when an unfortunate person stopped in a left turn lane well before the stop line. The vehicle didn’t trigger the sensor, so cycle after cycle went by and the traffic system never gave the left turn lane a green light, thinking the lane was unoccupied. Had the driver known about this the world would have been a better place. The first step in intelligent automation is sensing, and there are a variety of methods used to sense traffic’s flow.

Continue reading “The Sensors Automating Your Commute”

Automotive Radar and the Doppler Effect

With more and more cars driving themselves, there is an increasing demand for precise environment aware sensors. From collision avoidance to smooth driving, environmental awareness is a must have for any self-driving cars. Enter automotive radar: cool, precise and relatively cheap. Thanks to a donated automotive radar module, [Shahriar] gifts us with a “tutorial, experiment and teardown.”

Before digging into the PCB, [Shahriar] explains the theory. With just enough math for the mathmagically inclined and not too much for the math adverse, [Shahriar] goes into the details of how automotive radar is different from normal stationary radar.

Only after a brief overview of the Doppler effect, [Shahriar] digs into the PCB which reveals three die-on-PCB ASICs responsible for generating and receiving 77GHz FMCW signals coupled to a 2D array of antennas. Moreover, [Shahriar] points out the several microwave components such as “rat-race couplers” and “branchline couplers.” Additionally, [Shahriar] shows off his cool PCB rulers from SV1AFN Design Lab that he uses as a reference for these microwave components. Finally, a physical embodiment of the Doppler effect radar is demonstrated with a pair of Vivaldi horn antennas and a copper sheet.

We really like how [Shahriar] structures his video: theory, followed by a teardown and then a physical experiment to drive his lesson home. If he didn’t already have a job, we’d say he might want to consider teaching. If the video after the break isn’t enough radar for the day, we’ve got you covered.

Continue reading “Automotive Radar and the Doppler Effect”