| > What about input data? What about it? You get input data from data sources which, e.g., in a car it would be a sensor. The manufacturer of the sensor provides you with the guaranteed sensor accuracy for some inputs, which gives you the upper bound on the input error from that source. That is, in a reliable control pipeline, the upper bounds on the errors of data sources are known a priori. Sure, sensors can malfunction, but that's a different problem that's solved differently (e.g. via resiliency using multiple sensors). > A control system doesn't need to be end-to-end neural, by the way. Who's talking about end-to-end neural nets for control? If a single part of your control pipeline has unknown error bounds, your whole control system has unknown error bounds. That is, it suffices for your control pipeline to use a NN somewhere for it to become unreliable. This doesn't mean that you can't use control systems with unknown error bounds somewhere in your product, but it does mean that you can't trust those control systems. This is why drivers still need to keep their hands on the steering wheel on a Tesla: the parts of the pipeline doing the autonomous driving use NNs for image recognition, and the errors on that are unknown. This is also why all "self driving" cars have simpler data sources like ultrasonic sensors, radar, lidar, etc. which can be processed without NNs to avoid collisions reliably. You might still use NNs to improve the experience but those NNs are going to be overridden by reliable control pipelines when required. |
Now we have natural neural networks in the control loop for some reason despite their unknown error bounds. To give another example: is there a sensor for vehicle placement relative to road edges with known upper error bound, which is less than width of the road? No, we have GPS, radar, lidar, camera data that we need to interpret somehow.
A car that reliably avoids collisions (Can it, though? It needs to predict road situation to do it reliably), but can occasionally veer off the road, doesn't strike me as particularly safe.
> to be overridden by reliable control pipelines when required.
Those reliable pipelines needs to be mostly reactive. And there's a limit on what they can do. You can't avoid a collision when a car emerges from around a corner with 0.1 seconds to react. You need complex processing of those "simple" data sources to detect zones that can't be observed right now and to assess a probability of the said situation.
All in all, we already have unreliable human part in the control loop of a vehicle. A control system that is provably robust in all real world situations will be the ultimate achievement and not a prerequirement for wide use of self-driving cars.