E-Mobility with LibroDuct

Gegenverkehr 3 PS 646 x 220 Hindernis 3 PS 646 x 220 Haltestelle-5-PS-646-x-220 Kreuzung-2-PS-646-x-220 Abbiegen-PS-646-x-220


Electromobility has been gaining in relevance recently in view of sustainable urban and traffic planning movements although there have been electric trains, trams, trolleybuses and cars for over a century. Trolleybuses (also referred to as ‘catenary buses’) have not been able to gain general acceptance in competing with conventional diesel- or gas-powered buses although trolleybuses are not only cost efficient but energy efficient as well, and produce zero emissions. Since trolleybuses are largely affixed to overhead wires, manual intervention or even a structural solution is required when the bus has to be routed around a temporary obstacle. A supplementary energy source on board is useful to only a limited extent when encountering these obstacles, regardless of whether the source is a battery or auxiliary diesel. The net result of these disadvantages is that in Germany, for example, there are currently 23,000 diesel buses deployed in urban transport as opposed to less than 100 trolleybuses. Also, other e-mobility variants like battery- or fuel cell-powered buses or hybrid buses still pose too many limitations in terms of their operating range or convenience, or are considered to only be transitional technologies, i.e. not ready for prime time.

The solution: LibroDuct

DIaLOGIKa and project partner Kummler+Matter AG looked long and hard for solutions to this issue — and ultimately developed LibroDuct. With this system trolleybuses are able to connect to and disconnect from the overhead wire fully automatically, while travelling or stopped. LibroDuct is based on conventional pole current collector and overhead electrical contact wire systems. The LibroDuct principle is founded on a control system for which patent is pending at the international level. Combined with the novel mechanical components of the current collector system, for which patent is also pending, LibroDuct makes use of various software-based processes, enabling buses to automatically switch between operating with and without overhead lines, thus paving the way for the electrification of local public transport networks.

The technology

LibroDuct unites the positive aspects of trolleybus and battery-powered bus technologies. It enables battery-powered buses to recharge while underway (if only at bus stops), resulting in a drastic reduction in the battery capacity required. LibroDuct also enables trolleybuses to travel for extended distances without being connected to overhead lines. This means that with LibroDuct the construction of overhead lines can be cost-effectively restricted to main routes or specific bus stops and steep inclines requiring substantial electrical power. Thanks to their ability to autonomously disconnect from and recontact overhead lines, LibroDuct-enabled trolleybuses can easily master exceptional situations like sudden obstacles posed by accidents or temporary construction sites. Trolleybuses can also be used to serve heritage sites and historically protected areas without visually blighting them with overhead wires.

Key features

      • Software, not hardware

        Instead of relying on failure-prone mechanical sensors, the position of the overhead lines and current collectors is determined by way of stereoscopic pattern recognition using digital cameras. These signals control the components of the current collector system for precision disconnecting and recontacting.

      • Retrievers – a thing of the past

        The software also enables dewiring – when the trolley poles inadvertently slip off the overhead wires – to be detected and the poles to be reliably repositioned and resecured via the actuators controlling pole movement. Collision is prevented with the overhead wires, the other trolley pole or other obstacles, thus making this system superior to those employing conventional mechanical retrievers.

      Optional features

            • Car-to-car communication

              Digital communication (e.g. trunked radio or digital short range communication as per ITS-G5) is used to negotiate with other buses using the same overhead line to determine which of the two is to disconnect when passing or encountering a single pair of overhead wires.

            • Navigation via GPS and built-in digital map

              Thanks to its GPS system (and other sensors), LibroDuct always ‘knows’ where the bus is located. This information is compared with a stored route map containing details showing where overhead lines may be expected that the bus may contact, and which of possibly several pairs of overhead lines is to be used.

            • Communication with the control center

              LibroDuct automatically receives route information updates for its digital map from the control center via its digital wireless interface so that the driver only has to input the route ID at the beginning of a journey. LibroDuct does everything else. LibroDuct is also able to use this interface to transmit information about critical situations, e.g. obstacles, to the control center for dissemination to other buses.

            • Energy-efficient operation thanks to intelligent technology

              Using its digital map or statistical data from previous journeys, LibroDuct is able to predict the energy consumption and possible energy recuperation on the remaining portion of the route to be covered by the bus. This information is used by LibroDuct to optimize energy use and storage in the energy accumulator.

            Technology partners

            Logo Kummler+Matter AG LibroDuct is a codevelopment project of DIaLOGIKa and Kummler+Matter AG, to which both companies bring their specific expertise to the table. Kummler+Matter is a leading provider of electric contact lines for trolleybuses and other catenary solutions and a manufacturer of current collector components for trolleybuses. DIaLOGIKa is a systems specialist with over thirty years’ experience in the development of technically sophisticated software solutions. Both companies are members of trolley:motion, an action group of industry, mobility consultants and e-bus activists for advancing state-of-the-art trolleybus solutions.

            Have we piqued your interest?

            Dr. Jan Messerschmidt

            Dr. Jan Messerschmidt
            Managing Partner

            Telefon: +49 (6897) 935-222
            Telefax: +49 (6897) 935-422

            Don’t hesitate to contact us for any questions you might have concerning LibroDuct.

            Supported by funds from the government of Saarland and the European Union. Logos der Förderer - Supported by funds from the government of Saarland and the European Union.