I could be totally wrong, but I thought I read the emergency braking function was Volvo’s, and built into the base vehicle. Uber had disabled because they were testing their own software.
The NTSB report mentions the standard automatic emergency braking features from Volvo:
> The vehicle was factory equipped with several advanced driver assistance functions by Volvo Cars, the
original manufacturer. The systems included a collision avoidance function with automatic emergency
braking, known as City Safety, as well as functions for detecting driver alertness and road sign
information. All these Volvo functions are disabled when the test vehicle is operated in computer control
but are operational when the vehicle is operated in manual control.
However, that appears to be separate from emergency braking under Uber's self-driving system:
> At 1.3 seconds before impact, the self-driving system determined that an emergency braking maneuver was needed to mitigate a collision (see figure 2).[2] According to Uber, emergency braking maneuvers are not enabled while the vehicle is under computer control, to reduce the potential for erratic vehicle behavior. The vehicle operator is relied on to intervene and take action. The system is not designed to alert the operator.
> [2]: In Uber’s self-driving system, an emergency brake maneuver refers to a deceleration greater than 6.5 meters per second squared (m/s^2).
It sounds like Uber didn't trust their own self-driving system enough to allow it to initiate sudden crash stops. Too many false positives, I guess? Of course, simply disabling the function leads to other obvious problems, as shown.
That exactly what I was wondering. So Volvo's system was disabled (and they probably don't have any data from that system anyway) and so these quotes are specifically about Uber's system, which they seem to have full logs for?
That's a really weird interpretation. Uber's system could obviously brake but not 'emergency brake'? The system disabled a part of itself? How is that any different than it just never deciding to 'emergency brake'?
I think the better interpretation is that the Uber system disabled another separate (non-Uber) system.
Uber's system could obviously brake but not 'emergency brake'?
There are two systems in the vehicle. One is the manufacturer's, let's call it System V after Volvo, and the other is System U, for Uber.
System V provides collision detection and emergency braking. It played no part in this incident, since it's inactive if the car is under control of System U, which it was at the time.
System U can decide that the car should slow down in some situations. Let's call gradual slowdown Action U1, and emergency slowdown Action U2. The incident called for Action U2, by Uber's criteria. What Uber said is that a) they disabled automatic execution of Action U2, punting it to the driver (really, a bored passenger in driver's seat), and b) that the driver would get no indication of emergency situations from the system.
The idea is, presumably, that driver should watch the road and react in emergencies. But we also know that the driver had the duty of working with the onboard console, which must have been quite a distraction. Effectively, Uber has set themselves up for failure, and it happened.
Volvo has automatic driver-assistance emergency braking. That's turned off while Uber's self driving system is on, because obviously the two systems are not built to work together.
Uber also disabled emergency braking from their own system. That was because it would "drive erratically" when it was turned on.
Testing is not a valid reason for disabling it, because if it fires, then either Uber's system has failed to respond in time, or it is a false positive, and there cannot be many of those, or else it would be a problem with the relatively large numbers of otherwise ordinary Volvos equipped with emergency braking and being driven by humans.
That's not how I interpreted it. The report calls Volvo's system "advanced driver assistance functions" and "automatic emergency braking." When the report refers to "self driving systems" or "emergency braking maneuvers", they are talking about Uber's system.
