The Self-Driving Vehicle Concept Gets Safer
by Becky Harrison |
posted 30 July 2020
Worried about the idea of autonomous-driving vehicles? You might have cause, according to Oxbotica – a global leader in autonomous vehicle software. Up until now, the problem with full-autonomous vehicle tech has been the way that self-driving cars like these face signal black-outs caused by "urban canyons" in cities across the world, due to the continued growth of skyscrapers and urban infrastructure.
These Urban canyons are formed when a street is densely populated by tall buildings on both sides. This can cause the GPS signal at ground level to be degraded or lost, either through satellite signals being obscured, or through multipath effects: a phenomenon where radio waves bounce off surroundings and form multiple signal paths.
The number of tall buildings (above 200m) has risen by 650% in the last five years and with this number set to increase again by up to 20% in 2020, the frequency of urban canyons in our society is only set to grow. Interruption of GPS signals, through connection drops or multipath degradation, has potential safety and operational implications for autonomous vehicle systems that rely heavily on satellite-based navigation.
Even a standard three-storey building is enough to create signal disruption at ground level. And the problem is worse at higher latitudes where satellites tend to be lower in the sky. If no suitable fallbacks are in place, this can affect autonomous vehicles in these environments, including mass transit shuttles, buses, city delivery vehicles and cars.
However, canyons are not the only issue with GPS dependency. Sunspots formed during the sun’s 11-year magnetic field cycle cause marked changes in the solar wind. This impacts the upper atmosphere which can in turn interfere with GPS satellites. The solution is to use a mix of radars, cameras and lasers to navigate and localise rather than relying solely on GPS.
Oxbotica have come up with autonomy technology which is able to work independently of any external infrastructure, allowing continuous localisation and safe control of its vehicles - even without a GPS signal. Oxbotica’s localisation system is not reliant on a single sensor modality, and instead uses a mixture of radar, laser and vision sensing to deliver autonomous operation in a vast range of settings, on any vehicle platform, under any conditions.