With its feet on the ground, the railway system is experiencing its own industrial revolution, increasingly closer to aerospace technology. Currently the day is rare when cars without a driver do not appear in the headlines. Mobility, and especially urban mobility, tends more and more towards shared vehicles, electric vehicles and the self-employed. And the manufacturers know it. In August 2016, Ford revealed that starting in 2021, it plans to manufacture a fully autonomous vehicle to share in a chain. Meanwhile, Tesla is increasing the level of automatic driving in their vehicles, getting closer and closer to the autonomous car.
The race of car manufacturers and technological firms to take advantage of technology without a driver is a wake-up call for the railway industry. Road transport is already a major competitive threat for trains and any technology that facilitates its use will intensify that modal rivalry. But there are opportunities. Probably, the production in chain of the components that make possible the cars without driver, concretely of the sensors, will reduce the costs. This allows to rethink the technology of the automotive sector and to design a solution for the railroad systems specific railroad and get for the autonomy of the trains.
Automatic or autonomous?
The notion of autonomous trains raises an obvious question: Do not we already have them? Not yet. In today's rail systems, the most sophisticated current trains without a driver are automatic, but they are not really autonomous. The meters operated by CBTC are an example. At present, Thales' SelTrac CBTC solution has an unparalleled track record with more than 80 start-ups in 40 cities around the world. In the current CBTC rail systems, the ground system controls the train and, although the computers are the ones that govern the trains, they do not make decisions by themselves. External systems are responsible for sending instructions according to the information collected with the data received from the train.
The support of the latter imposes a series of limitations. One of them is the need for what is known as "secondary detection", which consists of a reserve positioning system. Earth systems, such as axle counters or track circuits, are necessary to achieve this and increase costs. The next step is to equip the train with sensors and processing capabilities, such as Google's car, so you can make your own decisions. Increasing its functions entails a reduction of infrastructures in the road, which reduces maintenance costs, thus marking a big difference.
Draw the panorama
An autonomous train must be able to do three things. First, you must know where it is. Secondly, he must be able to identify what is ahead. And finally, he must be able to make decisions about whether he travels or not. Sensors play a fundamental role in these matters. Thales engineering teams are currently working on a proof of concept for the autonomous operation of the trains. One of the aspects they are analyzing is the type of sensors that work best in rail systems. Without a doubt, radar is an option. It is good to detect other trains, but less effective when it comes to identifying people on the road. That's why you need instruments, such as optical sensors and cameras, which are the trend in autonomous cars. In addition to locating objects, the radar looks promising as a positioning technology: the train can be used to detect beacons mounted between the tracks. It does not need power, so the maintenance requirements are minimal.
Thales plans to introduce radar technology soon. Capacity and costs are two factors that determine the selection of sensors. Laser Imaging Detection and Ranging (LIDAR), for example, uses lasers to generate precise images in 3D. However, the cost is high. You can do a lot with the right cameras and software. For now, Thales is studying both solutions. The work of the company with respect to autonomy also focuses on the mechanisms of sensor fusion. These will allow the trains to draw a clear image of the surroundings, combining data from several of them. Even so, a centralized regulation is needed to coordinate what happens in the network of railway systems. This is where the CBTC system will continue to play an important role. Although safety functions criticize - including interlocking - they are likely to focus more on trains, central monitoring will continue to be necessary. Considering the margin to improve capacity, the reduction of operating costs and the elimination of ground infrastructure, it seems likely that subway systems are the first candidates for autonomy.
"In addition to detecting objects, the radar looks promising as a positioning technology"
However, technology offers potential in other fields. The autonomy could provide a lifeline to rural rail routes, enabling the reduction of operating costs, while maintaining or improving services. They could even have applications in the Fast Transit Bus System (BRT) market. Research in the field of train autonomy could also have important consequences for the development of ETCS in the case of conventional and high-speed line operations. It is likely that the next evolutionary step of the ETCS standard 3 will take advantage of, to a large extent, the advanced techniques outside the traditional railway field. Autonomous technology has a bright future and, undoubtedly, Thales will be able to make it possible.