Centimetre-accurate positioning is becoming increasingly important, particularly in the development of autonomous vehicles. Several projects are currently underway at RISE to develop this technology .
– "Automation can reduce the number of road accidents, but then the automation itself must be safe and proven to be better than a human driver," says Stefan Nord, Research Project Leader at RISE.
Self-driving cars, also referred to in industry as autonomous vehicles, are one of the initiatives for achieving the Swedish Parliament’s Vision Zero of no fatalities or serious injuries through road accidents.
– “Many of the road accidents today happen because the driver has become impaired in some way, like losing concentration or getting tired,” says Stefan Nord at RISE.
Development and testing still to come
However, before autonomous vehicles can be fully implemented in traffic, much more development and testing is required to prove that they are safer than the cars we use today.
– “Without that, they will never be accepted. Our biggest challenges right now have to do with this validation process and determining whether the automated systems work in real environments and situations,” says Stefan Nord.
This is where RISE and its subsidiary, AstaZero have an important role to play. Positioning is a vital aspect in the development of autonomous vehicles. The vehicles must not only be able to determine what’s around them, but also establish their own position and time in order to be able to share data with each other.
– “If a vehicle shares what its sensors see, but you don’t have its exact position and time, the information is worthless to other vehicles. You might also want to use the information to update a digital map, so accuracy is important,” says Stefan Nord.
World-leading in autonomous car testing
What many people might not know is that AstaZero has the world’s most advanced test environment for autonomous vehicles and associated systems.
– “I’d venture to say that we’re best in the world. We have the most advanced digital environment, as well as an extremely good set of various test tracks for developing these types of automated systems,” says Peter Janevik, CEO of AstaZero.
Autonomous vehicles are harder than people realise
Measurement with millimetre-accuracy
At the test track just on the outskirts of Borås, there are three masts belonging to Lantmäteriet’s (the Swedish mapping, cadastral and land registration authority) system for satellite positioning. It enables us to take measurements with millimetre-accuracy.
“Those working with geodesy and geodetic activities are interested in measuring continental drift, and heights above sea level, with great precision. The masts serve as our anchor points that we use to measure equipment which, in turn is used to measure autonomous vehicles. So for us, we’re talking about centimetre-accurate positioning,” says Stefan Nord.
The aim is to, in the future, be able to develop a service where vehicle manufacturers can visit AstaZero to test and verify how precisely their vehicle positions itself, along with the level of measurement uncertainty.
– “We’re doing research on the design of a system that we can use to validate or calibrate positioning systems. Manufacturers of autonomous vehicles could them come to AstaZero to test how accurately their vehicle positions itself in the coordinate system,” says Stefan Nord.
Development of satellite positioning
In the ongoing project at NPAD, RISE and AstaZero are also collaborating with others in the development of new technology within the field of satellite navigation and GNSS usage. The systems that currently exist for distributing correction data (needed for centimetre-accurate positioning and compensating for any sources of error) haven’t been expanded to cover the mass market and demand that will exist in a few years.
– “With lots of self-driving cars out on the roads and smartphones also wanting to use the technology, we’ll need to have efficient ways of distributing correction data. Otherwise, there will be bottlenecks,” says Stefan Nord.
PRoPART (Precise and Robust Positioning for Automated Road Transports) is another high-priority project. It is an EU funded cooperation project to develop and enhance an RTK (Real Time Kinematic) software solution by exploiting the distinguished features of Galileo signals. Galileo has, for example, a type of authentication protection in place to prevent it from being used for misleading purposes. The most known positioning system is GPS, which has entered the vernacular to mean satellite positioning. The US government created the system, maintains it, and makes it freely accessible to anyone with a GPS receiver. But the EU decided to create its own system, Galileo, so that it wouldn’t be dependent on USA.
Autonomous vehicles rely on more than just a single positioning system. In fact, they use as many systems as possible and are even used in situations and environments where they don’t have any satellite coverage at all. In tunnels for example, other sensors and systems take over (e.g. inertial guidance).
– “The more systems used, the better. You want multiple layers of redundancy so that if there is a problem with one system, another can be used instead,” says Stefan Nord.
Automated vehicles in traffic will need more time
Stefan Nord explains that there has been much discussion and debate as to how quickly we’ll actually start seeing self-driving cars out on our roads. The consensus now seems to be, however, that it will take longer than what many initially thought before we’ll see autonomous vehicles that don’t require monitoring by a driver out on the roads.
“We’re getting closer however, to solutions for self-driving vehicles in both underground and open mines, as well as port areas, for example. Many have realized though, that a future with self-driving vehicles in other situations will be more difficult than we first expected. A person at the wheel, for example, will slow down when a situation or environment feels uncertain or unfamiliar. Automated systems aren’t yet capable of making those kinds of assessments,” says Stefan Nord.