
Ask HN: Why are high-res maps vital to self-driving cars? - panabee
Could someone with expertise around self-driving cars kindly explain why high-res maps are vital to self-driving cars?<p>Cars must react in real-time to unmapped items like fallen trees, debris, and people (not to mention other cars), so what additional value do high-res maps provide?<p>Do they reduce processing time because now cars simply scan for deltas instead of the entire environment?
======
atroyn
This is a complex question. As you pointed out, having a high fidelity map
helps to identify the part of the environment that change, creating 'deltas'.

Another reason is that autonomous vehicles take data from a wide variety of
sensors, including cameras, RADAR, LIDAR and others.

None of these modalities is perfectly, and there is always ambiguity and
drift. High fidelity, high resolution maps provide a strong prior that helps
to resolve these issues.

Besides the sensing issues, high fidelity maps also provide priors with
respect to planning and prediction of the behaviors of other road users. A
busy intersection should be approaches differently to a small backroad.

In the end, autonomy needs both real-time processing and high fidelity maps to
perform effectively.

------
agitator
high-res maps help localize the vehicle. All of the sensors on the car
(cameras, GPS, radar, lidar, sonar) all have some degree of error, and have
their own respective strengths and weaknesses.

In order to know where the car is located at any given time, the vehicle uses
data from the gps and a combination of any of the other sensors to help
localize itself in the world. Relying on just GPS is risky and error prone, so
fuzing that position with matching landmarks from the field of view, or lidar
is a way to improve positioning.

This is especially important for determining which lane the vehicle is in,
where it needs to be in order to take a proper exit or turn, and what
potential obstacles or traffic scenarios it might encounter depending on where
it is located on a road.

------
starlord97
Check out this episode of a16z: [https://overcast.fm/](https://overcast.fm/)
BlzEcPXdQ

They go into details on use cases for HD maps

