A full mathematical simulation of a seated passenger was constructed with the aim of finding the shortest safe stopping distance for an unrestrained occupant of a personal rapid transit vehicle. lt was decided that the most useful form of deceleration was that of the trapezoidal shape, with defined jerk rates and maximum deceleration The design of the seat was to be one of a rigid structure with a compliant covering. The seat-back angle was then set at seventy degrees with a seat pan angle of five degrees rearward to help safety under braking but also ease normal running vibrations and aid comfort. The key factor was found to be the muscular response to the deceleration force of the passenger and this varied greatly with the age and the sex of the passengers. The worst case scenario had to be taken to ensure that the emergency stop would be safe for all the passengers concerned. This led to the model being used to determine the three factors and set an onset jerk of 40 m/s3, a maximum deceleration of 0.67 g (6.57 m/s2) and an end jerk of 100 m/s. This translates to a stopping distance of 10.31 m. Some initial tests have been carried out to try and verify the findings of the model and the results are encouraging. Further work is underway or planned to increase the accuracy of the model and help calibrate it with a larger data set. The model could then be used to set the system safety limits and also to define the 'normal' comfortable decelerations for the everyday running of the system. There are also other issues which could be investigated including the other factors which define the design headway and capacity of the system as well as many other issues concerned with seating position, likely passenger types and vehicle ride effects.
Passenger simulation to determine safety limits during emergency decelerations
Fahrgastsimulation zur Bestimmung von Sicherheitsgrenzen bei Vollbremsungen
2002
8 Seiten, 10 Bilder, 2 Tabellen, 26 Quellen
Aufsatz (Konferenz)
Englisch
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