Annual Report
INDUSTRY 4.0 TO GO - TUGGER TRAINS UNDERWAY WITHOUT DRIVERS

The mass production of self-driving cars may still be a long way off, but the production of non-autonomous cars with the help of autonomous vehicles is in full swing. 
Automated guided vehicles (AGVs) and their little siblings, small AGVs or automated guided carts (AGCs), have already been underway in production and logistics halls for some time now. Most of them, however, are line-guided or work on defined routes with fixed reference points. Forward-looking, Schiller Automatisierungstechnik GmbH even relies on complete tugger trains – that are autonomous and drive entirely freely – to ease the increased traffic in factory halls.

Self-driving tugger trains are already in use in the automotive industry. The electric trucks transport production goods to their next point of use on four trailers at ten kilometers per hour. With the help of contour-based localization, the tugger train knows exactly where it is at any time. The autonomous train does not need to be purchased completely new; the existing transport system can be used. A conventional electric truck serves as the basis, retrofitted by Schiller to create a driverless tugger train. This considerably reduces the investment costs. The conversion kit contains sensors for localization and vehicle protection, as well as a controller. The autonomous tugger train can also still be used manually with a driver. 
The abilities of the driverless tugger trains exceed the automation of earlier solutions. They enable dynamic route guidance according to delivery priorities and the active bypassing of obstacles. The autonomous control and navigation of the tugger trains takes place using the laser signals of NAV310 2D LiDAR sensors from SICK. These provide precise scanning data that is processed using an algorithm (also developed by SICK) in the SIM2000 Sensor Integration Machine. During processing, this algorithm continuously compares the distances determined from the current scanning data with the reference map, providing the current position and orientation angle of the vehicle without requiring any supplementary reflectors.
The market introduction of SICK’s microScan3 Pro safety laser scanner in summer 2018 was the breakthrough for the safety technology required to develop the autonomous tugger train. “It was relatively quickly clear that safety technology would be the central topic for the tugger train, because the main task when developing a tugger train, or operating with trailers in general, would be the trailers’ lack of line fidelity,” Peter Stoiber, Manager of Automotive Development at Schiller Automatisierungstechnik, explains the requirements. “The legal standard demands that any obstacle in the drive path must be detected and, if necessary, the vehicle must stop in such a way that no one can be endangered. The tractrix curves of the trailers must be taken into account when cornering. With big trailers this could well make a difference of one to one and a half meters, depending on the curve radius and angle.” The protective fields of the microScan3 Pro are ideal for cornering and parking: Flexible adaptation to the surroundings takes place with up to 128 freely configurable fields and eight simultaneous protective fields. Thanks to the protective fields, the tugger trains can gradually reduce their speeds. The protective field range of 5.5 m enables the high speed of the tugger trains and thus high throughput and high productivity.
»IT WAS RELATIVELY QUICKLY CLEAR THAT SAFETY TECHNOLOGY WOULD BE THE CENTRAL TOPIC FOR THE TUGGER TRAIN.«
PETER STOIBER, MANAGER OF AUTOMOTIVE DEVELOPMENT,
SCHILLER AUTOMATISIERUNGSTECHNIK
In view of the human-machine interaction, Schiller decided on a wearable mobile device: A smartwatch supports logistics employees during the container-changing process and announces approaching tugger trains via a vibration alarm. Employees can also read out which container they should unload and send the tugger train to its next destination via touchscreen. “With four trailers, the vehicle has a total length of almost ten meters. This means that if I remove the fourth container, I will have to walk the ten meters forward in order to activate the vehicle’s start button and then walk back again. These are all transit times that cost money at the end of the day. And this can be prevented with the watch,” Peter Stoiber describes the advantages.
The complexity of processes in production and logistics is constantly rising. The batch sizes to be produced are becoming ever-smaller. The aspiration remains: a level of efficiency that is equal to that of mass production. Flexibility and speed are called for. This is why rigid continuous conveyors in existing logistical solutions are being supplemented, e. g., with industrial trucks that drive around according to the taxi principle. A mixture of automated and manual processes will therefore have more and more influence on what the delivery chain will look like in future. This complicated logistical network requires efficient management. Transparency beyond system boundaries will be required more than ever: on the conveyor system, on the forklift, regarding the movement of pallets in the warehouse or in the next handling depot – along the entire value-creation chain.

In all this, localization technology is one of the keys to networked Industry-4.0-based production and logistics. It can be used to exploit numerous optimization potentials by enabling the agile planning of production and logistical processes. ///