1、 Reference number ISO 28981:2009(E) ISO 2009INTERNATIONAL STANDARD ISO 28981 First edition 2009-11-01 Mopeds Methods for setting the running resistance on a chassis dynamometer Cyclomoteurs Mthodes pour fixer la rsistance lavancement sur un banc dynamomtrique ISO 28981:2009(E) PDF disclaimer This PD
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5、 ISO 2009 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISOs member body in
6、the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2009 All rights reservedISO 28981:2009(E) ISO 2009 All rights reserved iiiContents Page Foreword i
7、v Introduction.v 1 Scope1 2 Normative references1 3 Terms and definitions .1 4 Symbols2 5 Test moped, chassis dynamometer and instruments .3 6 Required accuracy of measurements .4 7 Road test 4 7.1 Requirement for road 4 7.2 Ambient conditions for the road test 4 7.3 Reference speed5 7.4 Specified s
8、peed .5 7.5 Coastdown starting speed5 7.6 Coastdown time measurement beginning speed and ending speed.5 7.7 Preparation of test moped5 7.8 Rider and riding position6 7.9 Measurement of coastdown time.6 8 Data processing.8 8.1 Calculation of running resistance force8 8.2 Running resistance curve fitt
9、ing .8 8.3 Target running resistance force for chassis dynamometer setting.8 9 Chassis dynamometer setting derived from on-road coastdown measurements .8 9.1 Requirements for the equipment .8 9.2 Inertia mass setting.9 9.3 Warming up of chassis dynamometer 9 9.4 Adjustment of tyre pressures 9 9.5 Mo
10、ped warming up9 9.6 Procedures for setting chassis dynamometer .9 9.7 Verification of chassis dynamometer12 10 Chassis dynamometer setting using the running resistance table .12 10.1 Applicability .12 10.2 Requirements for the equipment .12 10.3 Setting the running resistance force on the chassis dy
11、namometer14 10.4 The specified speed for the chassis dynamometer.14 10.5 Verification of chassis dynamometer14 Annex A (normative) Moped description16 Annex B (normative) Chassis dynamometer and instruments description .18 Annex C (informative) Record of coastdown time and chassis dynamometer settin
12、g .20 Bibliography23 ISO 28981:2009(E) iv ISO 2009 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO techni
13、cal committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely w
14、ith the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft Int
15、ernational Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document m
16、ay be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 28981 was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 23, Mopeds. ISO 28981:2009(E) ISO 2009 All rights reserved vIntroduction This International Sta
17、ndard is based on ISO 11486:2006 6 , which specifies the measurement method(s) for determining motorcycle running resistance on the road, but adapted to the different vehicle category of mopeds. The most significant difference between this International Standard and ISO 11486:2006 6is that use of ch
18、assis dynamometers with a fixed load curve is permitted and a specific verification method is specified. INTERNATIONAL STANDARD ISO 28981:2009(E) ISO 2009 All rights reserved 1Mopeds Methods for setting the running resistance on a chassis dynamometer 1 Scope This International Standard specifies the
19、 measurement method for determining the moped running resistance on the road, and two methods of setting the chassis dynamometer with the moped running resistance. It is applicable to mopeds as defined in ISO 3833. 2 Normative references The following referenced documents are indispensable for the a
20、pplication of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 3833, Road vehicles Types Terms and definitions ISO 7116, Mopeds Measurement method for maximum speed 3 Ter
21、ms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 running resistance F total force resistant to a running moped which, when measured by the coastdown method, includes the friction forces in the drive-train 3.2 reference speed v 0moped speed at which
22、 the running resistance of the moped is calculated and then used for setting the chassis dynamometer 3.3 specified speed v moped speed at which the running resistance on the road is measured to determine the running resistance curve 3.4 moped kerb mass m kmoped dry mass to which is added the mass of
23、 the following: fuel: tank filled at least to 90 % of the capacity specified by the manufacturer; ISO 28981:2009(E) 2 ISO 2009 All rights reserved oils and coolant: filled as specified by the manufacturer; auxiliary equipment usually supplied by the manufacturer in addition to that necessary for nor
24、mal operation tool-kit, carrier(s), windscreen(s), protective equipment, etc. 3.5 moped reference mass m refkerb mass of the moped increased by a uniform figure of 75 kg which represents the mass of a rider 4 Symbols For the purposes of this document, the symbols in Table 1 apply. Table 1 Symbols Sy
25、mbols Definition Unit a The coefficient of polygonal function b The coefficient of polygonal function c The coefficient of polygonal function a TThe rolling resistance force of front wheel N b TThe coefficient of aerodynamic N/(km/h) 2d TThe relative air density under test conditions d 0The standard
26、 ambient relative air density F The running resistance force N F EThe set running resistance force on the chassis dynamometer N F E (v 0 ) The set running resistance force at the reference speed on the chassis dynamometer N F E (v i ) The set running resistance force at the specified speed on the ch
27、assis dynamometer N F fThe total friction loss N F f (v 0 ) The total friction loss at the reference speed N F jThe running resistance force N F j (v 0 ) The running resistance force at the reference speed N F pauThe braking force of the power absorbing unit N F pau (v j ) The braking force of the p
28、ower absorbing unit at the specified speed N F pau (v 0 ) The braking force of the power absorbing unit at the reference speed N F TThe running resistance force obtained from the running resistance table N F *The target running resistance force N F * jThe target running resistance force at the speci
29、fied speed N F * (v 0 ) The target running resistance force at the reference speed on the chassis dynamometer N F * (v i ) The target running resistance force at the specified speed on the chassis dynamometer N f 0The rolling resistance N f * 0The corrected rolling resistance in the standard ambient
30、 conditions N f 2The coefficient of aerodynamic drag N/(km/h) 2f * 2The corrected coefficient of aerodynamic drag in the standard ambient conditions N/(km/h) 2K 0The temperature correction factor for rolling resistance ISO 28981:2009(E) ISO 2009 All rights reserved 3Table 1 (continued) Symbols Defin
31、ition Unit m The test moped mass kg m aThe actual mass of the test moped kg m iThe equivalent inertia mass kg m fiThe flywheel equivalent inertia mass kg m kThe moped kerb mass kg m rThe equivalent inertia mass of all the wheels kg m refThe moped reference mass kg m ridThe rider mass kg m rfThe rota
32、ting mass of the front wheel kg m r1The equivalent inertia mass of the rear wheel and the moped parts rotating with the wheel kg p 0The standard ambient pressure kPa p TThe mean ambient pressure during the test kPa T TThe mean ambient temperature during the test K T 0The standard ambient temperature
33、 K v The specified speed km/h v jThe specified speeds which are selected for coastdown time measurement km/h v 0The reference speed km/h v 1The speed at which the measurement of the coastdown time begins km/h v 2The speed at which the measurement of the coastdown time ends km/h T EThe corrected coas
34、tdown time at the inertia mass (m i+ m r1 ) s T iThe average coastdown time at the specified speed s T jThe average coastdown time of the two tests s T roadThe target coastdown time s t The coastdown time s t The mean coastdown time on the chassis dynamometer without absorption s t EThe mean coastdo
35、wn time on the chassis dynamometer at the reference speed s t aiThe coastdown time measured during the first road test s t biThe coastdown time measured during the second road test s t iThe coastdown time corresponding to the reference speed s v The coastdown speed interval (2 v = v 1 v 2 ) km/h The
36、 chassis dynamometer setting error 0The standard relative ambient air volumetric mass kg/m 35 Test moped, chassis dynamometer and instruments A full description of the moped shall be provided in accordance with Annex A. A full description of the chassis dynamometer and instruments shall be provided
37、in accordance with Annex B. ISO 28981:2009(E) 4 ISO 2009 All rights reserved6 Required accuracy of measurements Measurements shall be made to the accuracies as specified in Table 2. Table 2 Required accuracy of measurements Parameter At measured value Resolution a) Running resistance force, F + 2 %
38、b) Moped speed (v 1 , v 2 ) 1 % 0,45 km/h c) Coastdown speed interval 2 v = v 1 v 2 1 % 0,10 km/h d) Coastdown time ( t) 0,5 % 0,01 s e) Total moped mass m k+ m rid 1,0 % 1,4 kg f) Wind speed 10 % 0,1 m/s g) Wind direction 5 h) Ambient temperature 2 K i) Barometric pressure 0,2 kPa 7 Road test 7.1 R
39、equirement for road The test road shall be flat, level, straight and smoothly paved. The road surface shall be dry and free of obstacles or wind barriers that might impede the measurement of the running resistance. The slope of the surface shall not exceed 0,5 % between any two points at least 2 m a
40、part. 7.2 Ambient conditions for the road test During data collecting periods, the wind shall be steady. The wind speed and the direction of the wind shall be measured continuously or with adequate frequency at a location where the wind force during coastdown is representative. The ambient condition
41、s shall be within the following limits: maximum wind speed: 3 m/s; maximum wind speed for gusts: 5 m/s; average wind speed, parallel: 3 m/s; average wind speed, perpendicular: 2 m/s; maximum relative humidity: 95 %; air temperature: 278 K to 308 K. Standard ambient conditions shall be as follows: pr
42、essure, p 0 : 100 kPa; temperature, T 0 : 293 K; relative air density, d T : 0,919 7; air volumetric mass, 0 : 1,189 kg/m 3 . ISO 28981:2009(E) ISO 2009 All rights reserved 5The relative air density when the moped is tested, calculated in accordance with the formula below, shall not differ by more t
43、han 7,5 % from the air density under the standard conditions. The relative air density, d T , shall be calculated by the following formula: 0 T T0 0T T p dd p T = (1) 7.3 Reference speed The reference speed or speeds shall be as defined in the test cycle. 7.4 Specified speed The specified speed, v,
44、is required to prepare the running resistance curve. To determine the running resistance as a function of moped speed in the vicinity of the reference speed, v 0 , running resistances shall be measured using at least four specified speeds, including the reference speed(s). The range of specified spe
45、ed points (the interval between the maximum and minimum points) shall extend either side of the reference speed or the reference speed range, if there is more than one reference speed, by at least v, as defined in 7.6. The specified speed points, including the reference speed point(s), shall be no g
46、reater than 20 km/h apart and the interval of specified speeds should be the same. From the running resistance curve, the running resistance at the reference speed(s) can be calculated. 7.5 Coastdown starting speed The coastdown starting speed shall be more than 5 km/h above the highest speed at whi
47、ch coastdown time measurement begins, since sufficient time is required, for example to settle the positions of both the moped and rider and to cut the transmitted engine power off before the speed is reduced to v 1 , the speed at which the measurement of the coastdown time is started. 7.6 Coastdown
48、 time measurement beginning speed and ending speed To ensure accuracy in measuring the coastdown time, t, and coastdown speed interval, 2 v, the beginning speed, v 1 , and ending speed, v 2 , in kilometres per hour, the following requirements shall be met: v 1= v + v (2) v 2= v v (3) v shall be 5 km
49、/h when v is less than 60 km/h, and shall be 10 km/h when v is 60 km/h or more. 7.7 Preparation of test moped 7.7.1 The moped shall conform in all its components with the production series, or, if the moped is different from the production series, a full description shall be given in the test report. 7.7.2 The engine, transmission and moped shall be properly run in, in accordance with the manufacturers requirem
