Is it really in the right spot?
Their advantage, compared to the internal combustion engines used currently in city busses, is obvious: no exhaust. The disadvantage of electric busses is, however, their limited range per battery charge. One way of solving this problem would be rapid-charging of the battery and not just overnight in the bus garage but right during operation on city streets. So, for example, one could use the busses’ waiting times at the stops of their route to reload the battery. To do this, a so-called pantograph would dock onto the bus from above. As soon as contact was produced, electricity would start to flow to recharge the battery. Since a bus is, as a rule, only briefly at its stops, the pantograph would have to dock as quickly and precisely as possible.
Max Bergfeld of BFFT Berlin addressed this problem in his Bachelor thesis. He developed image processing software that assured the correct positioning of the bus beneath the pantograph. Here’s how it works: The live data needed for the image processing are captured by a camera mounted on the mast of the pantograph. As soon as the bus is in the correct position, the pantograph docks onto the bus for loading. In order to avoid false positives, various interference factors such as fog, shade, a covered camera lens, etc. would have to be accounted for. In Max’s thesis, the qualitative effect was determined by simulation as well as by experiment. The result: Recognizing the position of the bus by means of a camera succeeds even under adverse environmental conditions — but only by day and not at night for bus stops that are not illuminated. That is why it is not suited for placement in city traffic, at least for now. However, since the system was configured to be hardware-independent, its introduction in other situations that require recognizing the positioning of objects is conceivable.
Max presented his results at Engineering Informatics Day at the HTW Berlin on 27 April. After successfully completing his Bachelor studies, Max will remain at BFFT as a student trainee. And since his colleagues in Berlin have been working for some years on the development of electric busses, additional exciting projects are continually being offered there. Maybe there is one that would interest you? Take a look at the BFFT Jobs Page – it just might be worth your while!