Bruno Latour, Aramis, or the Love of Technology, PDF - Dss-edit.com

[SUMMARY OF A GROUP INTERVIEW]The same speakers:"If the Aramis cars feel each other out by way of ultrasound detectors, theyrun the risk of bumping into each other or staying too far apart, becauseultrasound echoes are scattered in tunnels and on curves. We'd have toseparate the trains and slow down the cars when they merge and demerge .But that would disrupt the rhythm and reduce the speed, and Aramis' advantages,its train configuration, would disappear. So Matra has to find somethingelse to maintain the performance levels."All guided-transportation systems, trains and metros, are based on theprinciple of fixed sectors. The track is divided up into sections and no vehicleis authorized to enter one section before the vehicle ahead of it has left-thatis, before the red light of each section has turned green. Tra ins and subwaysare equipped with a simple injunction: never cross a sector's red light, whetherthe light is interpreted by a human being or by the motor directly."But if the train is going ten kilometers on hour, it can broke faster than whenit's doing sixty, so it can follow the train ahead more closely without increasingthe danger. However, the sector doesn't authorize this, because it remainsunawore of this margin for negotiation. It maintains a constant distance betweentrains, no matter what their speed."It's like a cop who tokes away all the flexibility from trains and subwaysin exchange for a considerable margin of security. * A procedure like this isn'tappropriate for Aramis, since the car has to be able to connect up with thecars that precede it and form a tra in with nonmaterial couplings. So it has topenetrate the sector ahead by feeling its way. But if it's authorized to go intothe safety sector, then its means of recognition have to be absolutely failsafe.Otherwise, if it's too forceful, it'll crash into the other cars, or, if it's too timid,it'll stay so far away that it'll slow down the flow of the vehicles behind"Matra comes up with a radical solution, one already considered for VALbut then abandoned because of its complexity. It involves doing without thesacrosanct fixed sectors, in exchange for increased intelligence on the part ofthe cars. The Aramis vehicle is endowed with the means to negotiate its ownspeed and safe distance on its own, no longer by means of fixed sectors*Even SACEM a model for assisted driving, recently installed on Line A ofthe RER, which makes it possible to bring trains closer together than the humandrivers present in the cabin would dare to do reduces the intervals only by dividingup the fixed sectors into smaller units. [t docs not do away with fixed sectors.ARAMIS AT THE CET SIAGE