ISO 26262 sets out the safety requirements for autonomous vehicles, including so-called ‘functional safety’. This covers the vehicle’s ability to safely respond to errors, either in its firmware or its hardware, ultimately to keep passengers safe. To meet these requirements, the sorts of systems we’ve just described are vital.
However, while functional safety is an essential component of autonomous vehicle safety, it only covers errors that could happen on the vehicle itself. As we’ve seen, when it comes to positioning, the key areas for error are external to the vehicle. So even if a vehicle was functionally safe, it wouldn’t know to reject inaccurate positional data. Consequently, you need a more comprehensive safety approach, called ‘integrity’. This would look at the complete technology landscape, including the sensors, security systems and V2X communications. Integrity demands that every piece of technology identifies how confident it is in the output it is providing. If this confidence drops too low, the vehicle will know when to switch to an alternative technology.
The foundations for future motoring
High GNSS accuracy is a central enabler of advanced driver-assistance systems (ADAS) and completely autonomous vehicles that ultimately improve road safety. Using multi-band receivers and SSR correction data, high precision GNSS provides a reliable reading of the vehicle’s position, irrespective of the circumstances. Accuracy will need to be down to the decimeter-level on open highways, and for now less than a meter on more complex city roads. And as well as being highly accurate when it comes to pinpointing the vehicle’s physical location, the position reading needs to be delivered with a very high degree of confidence in its accuracy. And lastly, if the technology is to achieve mass market adoption, it will need to work flawlessly and be affordable.