UIC comfort tests - VTI

More documents

Recommendations

Info

13.3 Conclusions in relationship with the organisation oftests13.3.1 Choice of the test trackThe test track should be chosen in such a way that all relevant situations arepresent in a sufficient number (See.7.2).13.3.2 Choice of the test vehicleIt is necessary to be able to control the settings of the tilting control system of thetest vehicle in order to obtain a sufficient spread in potential results. (See 8.4.2).13.3.3 Choice of place in the coachIt is obvious that ideal positions in the coach, having the “optimal compensation”are present in limited number. The number of “optimal” and “non optimal”positions should be optimised to obtain best results. (See 8.4.3).13.3.4 SynchronisationIt is important to synchronise the questioning of test people as well as possiblewith the zones to be judged, if possible independently in each vehicle. (See 8.3.3).13.3.5 Nature of the databasesThe working group only had access to a restricted database. This databasecontained only evaluated values chosen by the working group and allowed by theowners of the test vehicle.Without any doubt, the possession of a digital time history of relevant datawould be a decisive advantage in this kind of investigation, because the possibilityto create “on the fly” parameters that seem better adapted to the problem.(See 8.5.2).13.3.6 Number of events in the experimental databaseDue to the natural spread of responses with a human origin (votes), the number ofindependent data present in the experimental databases should be as large aspossible.The actual average comfort test is based on 153 independent observations, for4 parameters. 40 observations/parameters is to be considered as an absoluteminimum. (See 12.2.7).13.4 Interpretation of the results13.4.1 Many parameters are correlatedMany of the parameters initially chosen as possible influences are correlated. Theparameters having the lowest mutual correlation factors and giving higheststatistical quality are chosen. So it is possible to find other groups of parametershaving nearly equal statistical description. (See chapters 11 and 12).VTI notat 56A-2003 111
13.4.2 Parameters representing shorter events do give betterstatistical resultsInitially parameters representing the averaged value, calculated on 0.1, 0.4 and 1second were introduced into regression. Maximum values of 0.1 second averagedvalues give better statistical results. (See Table 11-5 and Table 11-6).13.4.3 The spread of the votes is considerableAs could be expected, the spread of the votes in identical situations is important.This is conforms with the spread already observed in the study of equal sensationcurves. As a consequence a large number of test persons are needed. Thirty-twotest-persons are an absolute minimum to obtain acceptable results. Moreconvincing results will be obtained using 80–100 test persons.13.4.4 The individual influences are well defined by their associatedt-parametersIn spite of the spread, the statistical parameters associated with the regressionsconfirm without hesitation the chosen parameter as “non-zero”. (See most of theregression tables).13.5 Influence of construction detailsConstruction details of the train as well as the tilt control system do have aninfluence on the comfort of the people in the train, because it is impossible tobalance the lateral acceleration with the same amount of tilt for all position in thevehicle, i.e. the time delay can only be zero for one position in the vehicle. (Timedelays of the order of 100 ms or less are probably not noticeable and have noinfluence on comfort). (See chapter 9).13.5.1 Influence of the length of the transitionIn a transition curve, the tiling angle of the car body is only optimal for oneposition in the vehicle. The longer the transition curve the smaller is the differencein lateral acceleration felt by a passenger seated in the front of the vehicle incomparison with the lateral acceleration felt by a passenger seated at the end ofthe same vehicle.(Short transition curves have other disadvantages such as high levels of rollvelocity, roll acceleration and jerk).13.5.2 Influence of the length of the vehicleThe length of the coach has an influence on the balance of forces, because of thedifference between the local radius of the transient curve under the centre of thebogies. (See 9.4.2).13.5.3 Influence of the control of the tilting systemThe synchronisation between the beginning and end of the transition curve and thebeginning and end of the tilting motion should be as accurate as possible to avoidthe problem with time delay between tilt motion and lateral acceleration at thetrack level. Time delays provoke both unnecessary levels of lateral accelerationsand jerks.112 VTI notat 56A-2003
Page 1 and 2:
VTI notat 56A • 2003VTI notat 56A
Page 3 and 4:
ContentsPageAbbrivations and Notati
Page 5 and 6:
10.5.1 Transitions 5311 Evaluation
Page 7 and 8:
Abbrivations and NotationsAEAT AEA
Page 9 and 10:
chosen test track with a minimum of
Page 11 and 12:
1.8.2 ModelsThree different models
Page 13 and 14:
3 What does comfort mean in the con
Page 15 and 16:
Representation of passengers’ opi
Page 17 and 18:
4 How comfort evolves with speed4.1
Page 19 and 20:
Each element may provoke a potentia
Page 21 and 22:
5.2.2 Theoretical behaviour of thos
Page 23 and 24:
Nominal acceleration in the horizon
Page 25 and 26:
6 Actual evaluation rulesAll the fo
Page 27 and 28:
Important variancesS 0 = var(y)Sr =
Page 29 and 30:
7 Choice of the test zone7.1 Choice
Page 31 and 32:
9.008.007.006.00roll velocity5.004.
Page 33 and 34:
8 Description of the test8.1 The tr
Page 35 and 36:
8.3.3 Synchronisation between votes
Page 37 and 38:
8.5 Registration of data, calculati
Page 39 and 40:
DRIVER CAB8.6.2 Occupied places2224
Page 41 and 42:
9.3 Study of the car body angle9.3.
Page 43 and 44:
9.4.2 Influence of length of the co
Page 45 and 46:
9.4.4 Additional discomfort due to
Page 47 and 48:
10.1.1 ConclusionsThe actual distri
Page 49 and 50:
10.3 Seat positionThe influence of
Page 51 and 52:
Average votes for the different tra
Page 53 and 54:
Figures 10-5 to 10-10 show the infl
Page 55 and 56:
Influence by roll velocity on voteA
Page 57 and 58:
5.0Influence by Pct on voteAll cate
Page 59 and 60: 11 Evaluation of local comfort11.1
Page 61 and 62: 11.1.4 Scaling of votesThe N’ VA
Page 63 and 64: Note that very high values of later
Page 65 and 66: 554433N'vaN'va221100 1 2 3 4Lateral
Page 68 and 69: Multiple regressions have therefore
Page 70 and 71: With the 1.0-second window, the jer
Page 72 and 73: The regression has been repeated wi
Page 74 and 75: (Table 11-12)Object: Simple and adj
Page 76 and 77: simple transitions, and with the re
Page 78 and 79: Table 11-18 Regression for track en
Page 80 and 81: Some characteristic data points of
Page 82 and 83: The probability that all coefficien
Page 84 and 85: Second conclusionThis also proves t
Page 86 and 87: number of real votes3025201510500,2
Page 88 and 89: 11.2.2 ParametersFour parameters we
Page 90 and 91: There are some observations from th
Page 92 and 93: Table 11-30 Two-parameter regressio
Page 94 and 95: Three-parameter regression - N'VA,
Page 96 and 97: The three-parameter regression was
Page 98 and 99: 12 Evaluation of average comfort12.
Page 100 and 101: Table 12-2 shows that the correlati
Page 102 and 103: 3.53.5332.52.5NVA21.5NVA21.5110.50.
Page 104 and 105: Table 12-5 Multiple regression for
Page 106 and 107: This is the preferred result to be
Page 108 and 109: 12.2.5 Density of importance of eac
Page 112 and 113: An identical observation can be mad
Page 114 and 115: 13.7.3 Evaluation of local comfort
Page 116 and 117: Appendix 1Page 1 (3)1 Preparing the
Page 118 and 119: Appendix 1Page 3 (3)2.5 Publish res
Page 120 and 121: Appendix 2Page 2 (10)For this progr
Page 122 and 123: Appendix 2Page 4 (10)Vertical accel
Page 124 and 125: Appendix 2Page 6 (10)Influence of l
Page 126 and 127: Appendix 2Page 8 (10)Red line : 0.1
Page 128 and 129: Appendix 2Page 10 (10)Study of aver
Page 130: Appendix 3Page 2 (2)Evaluation of h
show all

UIC comfort tests - VTI

Create successful ePaper yourself

Delete template?

Save as template?