Solid objects that arent too dark or too shiny. Lidar is very bad at detecing mirrored surfaces or non-reflecting structures that absorb the paticular frequency in use. The back ends of trucks hauling liquid are paticularly bad. Block out the bumper/wheels, say by a slight hill, and that polished cone is invisible to lidar.

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bayindirh 5 days ago | parent | next [-]

Add one or a couple of RADAR(s), too. European cars use this one weird trick to enable tons of features without harming people or cars.

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UltraSane 5 days ago | parent | prev [-]

LIDAR works be measuring the time it takes for light to return so I don't understand how a object can be too reflective. Objects that absorb the specific wavelength the LIDAR uses is an obvious problem.

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sandworm101 5 days ago | parent [-]

Too reflective, like a flat mirror, will send the light off in a random direction rather than back as the detector. Worse yet, things like double reflections can result in timing errors as some of the signal follows a longer path. You want a target that is nicely reflective but not so shiny that you get any double reflections. The ideal is a matte surface painted the same color as the laser.

	▲	UltraSane 5 days ago \| parent [-]
		Ah it relies on diffuse reflections to guarantee some light returns to the sensor but specular reflections mean none is returned. This is a good example of why sensor fusion is good.