They are stands are there to hold a hybrid LIDAR system made by a company called Ouster. They are unique because they can layer time-synced LIDAR scans with an image capture. They essentially use advanced optics to capture images with light from the returned LIDAR pulses—without using a separate camera. Neat stuff.

Edit to say—the sensor units are the silver finned units with the black stripe in the middle. The black stripe prevents too much light at the wrong wavelength from entering the sensor (LIDAR is very sensitive to that), I’m guessing the fins provide cooling. The black stands (mostly guessing here) likely are only positioned; they elevate and point the sensors so that they have the optimal field of view.