How Will Autonomous Cars Respond to Emergency Vehicles? Posted on : Aug 02 - 2018

As we get closer to the widespread deployment of autonomous vehicles, there’s still discussions about what sensors will be required to make these vehicles safe – for the passengers and other pedestrians and vehicles. Those discussions usually revolve around cameras, radar, LiDAR (Light Distance and Ranging), and ultrasonic. There’s one other sensor that isn’t discussed – an audio microphone.

I recently experienced a situation that caused me concern over how well an autonomous car would handle emergency vehicle awareness. I was stopped at a red light in the left-hand turn lane on a local road. There was a large panel truck immediately to my right. Just before the turn light turned green, I heard the siren of an approaching fire engine. I could not see the fire engine because of the panel truck and the distance involved, but I could *hear* the approaching emergency vehicle. When an emergency vehicle (law enforcement, fire and medical) approaches, all other traffic must stop or move to the right side to allow the emergency vehicles pass through. Adding a sense of hearing has not been high on autonomous vehicle priorities, if even considered at all. How would an autonomous car know to hold at the green light and not proceed? While its radar, liDAR, and camera sensors are always scanning 360 degrees around the vehicle, those sensors may not be able to see around obstacles like trucks, buildings, etc.

I recently talked to an automotive engineer and he contented that the constant awareness of autonomous vehicle sensors provides better circumstance awareness. I don’t argue that point, but some information is not within visual range and emergency vehicle response is one potential problem. There are weather proof microphones available, and the processing requirements for siren recognition is a well bounded problem. For now, we will need to rely on the driver being able to respond and take over control of the vehicle.

The Long-term solution is V2V and V2X

The long term solution to this problem will be vehicle-to-vehicle (V2V) and vehicle-to-everything (V2X) radio connections. These radio links provide a valuable adjunct to the other sensors. With V2X, the autonomous vehicles communicate to each other providing live information that can range beyond the range of the other sensors. With V2X, other vehicles with a better view could warn all cars that an emergency vehicle was coming. It would be best if the emergency vehicles could transmit information to all cars in the local area signally them to hold position. A V2X system might also work in a similar way with sensors on local structures, like light poles, even pedestrians, that could transmit the emergency warnings. View More