When I worked at Boeing, I talked about autoland systems with my lead engineer. He said the autoland was too perfect, as the airplanes would touch down at the same place every time.

This caused that place in the runway to suffer severe fatigue damage.

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psunavy03 11 hours ago | parent [-]

IIRC, there was a similar problem on aircraft carrier flight decks, where they had to induce some randomized amount of dispersion to keep the tailhook from hitting the same spot over and over again.

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krisoft 8 hours ago | parent | next [-]

I work at a self-driving car company and we observed a similar problem when we did some off-road testing on dirt tracks. The cars were too precise and they were cutting deep ruts into the soil. We too solved it by adding a pseudo-random offset to the track.

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bobthepanda 7 hours ago | parent | next [-]

Before the current wave of automation there was a previous technology to automate buses using optical sensing and lines in the road which had the same issue.

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mikepurvis 4 hours ago | parent | prev [-]

I believe Google Maps adds a bit of a rng in which route it will recommend when two otherwise similar in distance/time. Obviously the traffic input also affects this, but that's a slower feedback mechanism; better to distribute the cars all leaving the airport for downtown across the 2-3 possible routes upfront rather than dumping them all onto route A until it's a jam and then all onto route B until it's a jam, etc.

	▲	bigiain 3 hours ago \| parent [-]
		Annealing.

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refibrillator 10 hours ago | parent | prev | next [-]

Hmm in distributed computer systems similar patterns exist, e.g. adding jitter to avoid thundering herd effects.

This feels like an essential pattern of the universe or something…

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HPsquared 9 hours ago | parent [-]

"Spread spectrum" is used in EE to spread out the frequency ranges used and reduce interference. The extreme version being CDMA.

	▲	username135 9 hours ago \| parent [-]
		Intriguing

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cucumber3732842 8 hours ago | parent | prev [-]

Citation please. Doesn't pass the sniff test.

I suspect the ocean in its various states provides quite a bit of dispersion. Replacing deck plates on a ship is a normal part of maintenance. I find it very hard to believe they'd induce randomness rather than having just that one plate get a different hardness (I know some people will screech about that but trust me, the warship industry is well practiced at such things).

	▲	Cerium 6 hours ago \| parent \| next [-]
		I interpreted the effect here not to be on the deck plates but to be the point of impact between the cable and the hook. Sudden bends in cables can wear them fairly quickly in the immediate vicinity. I'm sure you can extend cable life proportionally to the spread of the loading.
	▲	Onavo 7 hours ago \| parent \| prev [-]
		Not sure about the ocean industry but carrier landings have full autoland support for a long time (see e.g. magic carpet).