1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 14792:2011Road vehicles Heavycommercial vehicles and buses Steady-state circular testsBS ISO 14792:2011 BRITISH STANDARDNational forewordThis British Standard is the UK im
2、plementation of ISO 14792:2011. Itsupersedes BS ISO 14792:2003 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee AUE/15, Safety related to vehicles.A list of organizations represented on this committee can beobtained on request to its secretary.This publi
3、cation does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. BSI 2011ISBN 978 0 580 72781 8ICS 43.080.01Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the aut
4、hority of theStandards Policy and Strategy Committee on 31 March 2011.Amendments issued since publicationDate Text affectedBS ISO 14792:2011Reference numberISO 14792:2011(E)ISO 2011INTERNATIONAL STANDARD ISO14792Second edition2011-03-15Road vehicles Heavy commercial vehicles and buses Steady-state c
5、ircular tests Vhicules routiers Vhicules utilitaires lourds et autobus Essais sur trajectoire circulaire en rgime permanent BS ISO 14792:2011ISO 14792:2011(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file may be printed or viewed b
6、ut shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In downloading this file, parties accept therein the responsibility of not infringing Adobes licensing policy. The ISO Central Secretariat accepts no liability in this
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8、se by ISO member bodies. In the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below. COPYRIGHT PROTECTED DOCUMENT ISO 2011 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in
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10、 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2011 All rights reservedBS ISO 14792:2011ISO 14792:2011(E) ISO 2011 All rights reserved iiiContents Page Foreword iv Introduction.v 1 Scope1 2 Normative references1 3 Test objectives.1 4 Variables and reference system
11、 2 5 Measuring equipment .2 6 Test conditions 2 7 Test procedures.3 7.1 General .3 7.2 Constant radius test3 7.3 Constant speed, variable-steer angle test 3 7.4 Common test conditions 3 8 Data analysis4 8.1 General .4 8.2 Steering-wheel angle.4 8.3 Centripetal acceleration4 8.4 Curvature of trajecto
12、ry4 9 Data evaluation and presentation of results 4 9.1 General .4 9.2 Other evaluations and presentation of results.5 Annex A (normative) Test report Presentation of results8 Bibliography13 BS ISO 14792:2011ISO 14792:2011(E) iv ISO 2011 All rights reservedForeword ISO (the International Organizatio
13、n 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 technical committees. Each member body interested in a subject for which a technical committee has been established has
14、 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 with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Inter
15、national 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 International Standards adopted by the technical committees are circulated to the member bodies for voting. Publicat
16、ion 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 may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent righ
17、ts. ISO 14792 was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 9, Vehicles dynamics and road-holding ability. This second edition cancels and replaces the first edition (ISO 14792:2003), of which it constitutes a minor revision. BS ISO 14792:2011ISO 14792:2011(E) ISO 201
18、1 All rights reserved vIntroduction The main purpose of this International Standard is to provide repeatable and discriminatory test results. The dynamic behaviour of a road vehicle is a very important aspect of active vehicle safety. Any given vehicle, together with its driver and the prevailing en
19、vironment, constitutes a closed-loop system that is unique. The task of evaluating the dynamic behaviour is therefore very difficult since the significant interaction of these driver-vehicle-environment elements are each complex in themselves. A complete and accurate description of the behaviour of
20、the road vehicle must necessarily involve information obtained from a number of different tests. Since this test method quantifies only one small part of the complete vehicle handling characteristics, the results of these tests can only be considered significant for a correspondingly small part of t
21、he overall dynamic behaviour. Moreover, insufficient knowledge is available concerning the relationship between overall vehicle dynamic properties and accident avoidance. A substantial amount of work is necessary to acquire sufficient and reliable data on the correlation between accident avoidance a
22、nd vehicle dynamic properties in general and the results of these tests in particular. Consequently, any application of this test method for regulation purposes will require proven correlation between test results and accident statistics. BS ISO 14792:2011BS ISO 14792:2011INTERNATIONAL STANDARD ISO
23、14792:2011(E) ISO 2011 All rights reserved 1Road vehicles Heavy commercial vehicles and buses Steady-state circular tests 1 Scope This International Standard specifies tests for determining the steady-state directional control response of heavy vehicles, one of the factors composing vehicle dynamics
24、 and road-holding properties. It is applicable to heavy vehicles, i.e. commercial vehicles, combinations, buses and articulated buses as defined in ISO 3833, covered by Categories M3, N2, N3, O3, and O4 of UNECE (United Nations Economic Commission for Europe) and EC vehicle regulations. These catego
25、ries pertain to trucks and trailers with a maximum mass above 3,5 t and to buses and articulated buses with a maximum mass above 5 t. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies
26、. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 3833, Road vehicles Types Terms and definitions ISO 8855, Road vehicles Vehicle dynamics and road-holding ability Vocabulary ISO 15037-2:2002, Road vehicles Vehicle dynamics test methods P
27、art 2: General conditions for heavy vehicles and buses 3 Test objectives The general conditions for variables, measuring equipment and data processing, environment (test track and wind velocity), test vehicle preparation (tuning and loading), initial driving, and the reporting of general data and te
28、st conditions of general significance, independent of the specific vehicle dynamics test procedure, shall be as specified in ISO 15037-2. They shall apply when vehicle dynamics properties are determined unless other conditions are required in the standard for the test procedure actually used. BS ISO
29、 14792:2011ISO 14792:2011(E) 2 ISO 2011 All rights reservedAlthough this International Standard is intended for combination vehicles as well as for single-unit vehicles, Clauses 8 and 9, regarding data analysis, evaluation and presentation, deal only with the motion variables of the single-unit vehi
30、cle or of the first unit of combinations. Thus, in order to comply with this International Standard, the user shall meet the requirements for variables, measuring equipment and data handling only in as far as they apply to the single-unit vehicle or to the first unit of combinations. Nevertheless, u
31、sers are encouraged to measure and analyse the motions of trailing units as appropriate to their particular purposes. The primary objective of this test procedure is to determine the steady-state turning characteristics of heavy vehicles for both left- and right-hand turns. The steady-state turning
32、behaviour of unit vehicles which have more than two axles and/or dual or wide-base tyres, as is the case with most heavy vehicles, is known to be a strong function of both centripetal acceleration and path curvature34. To characterize the steady-state behaviour of these vehicles, it is therefore nec
33、essary to conduct turning tests on different radii turns as well as at varying levels of centripetal acceleration. Such a test program may be accomplished through a series of constant radius tests conducted at various radii, or through a series of constant speed, variable-steer angle tests conducted
34、 at different speeds. Indeed, it is desirable that both types of tests be conducted for a full characterization of the steady-state turning of these vehicles. The constant radius test requires the test vehicle to be driven at a constant speed on a path of known, constant radius. The directional cont
35、rol response characteristics are determined from data obtained by repeating the procedure at successively higher speeds. To fully characterize the steady-turning of the vehicle, this procedure shall then be repeated for various radii. The procedure may be tailored to existing test track facilities b
36、y selecting circles or paths of appropriate radii. The constant speed, variable-steer angle test requires the test vehicle to be driven at a constant speed and constant steer angle. The directional control response characteristics are determined from data obtained by repeating the procedure at succe
37、ssively greater steer angles. To fully characterize the steady-turning of the vehicle, this procedure shall then be repeated at various speeds. 4 Variables and reference system The variables to be determined may be selected for test purposes from those given in ISO 15037-2 and shall be monitored usi
38、ng appropriate transducers. The variables relate to the intermediate axis system (X, Y, Z) (see ISO 8855). For the purposes of this International Standard, the reference point shall be the centre of gravity of the vehicle unit. This provision overrides the similar provision of ISO 15037-2. Strictly
39、speaking, the steady-state turning performance ought to be evaluated based on centripetal acceleration, ac, rather than on lateral acceleration, aY, (see ISO 8855). In most practical situations, however, the difference between these two quantities is small and can be ignored. Nevertheless, in a few
40、cases (e.g. long-wheelbase vehicles operating on small turning radii or any vehicle operating at large body sideslip angles), the difference could be appreciable. In these cases, measured lateral acceleration needs to be corrected for sideslip angle to determine centripetal acceleration. In any case
41、, this document refers to centripetal acceleration throughout rather than to lateral acceleration. 5 Measuring equipment The measuring and recording equipment shall be in accordance with ISO 15037-2. 6 Test conditions The limits and specifications for ambient and vehicle test conditions shall be in
42、accordance with ISO 15037-2. BS ISO 14792:2011ISO 14792:2011(E) ISO 2011 All rights reserved 37 Test procedures 7.1 General The general test specifications shall be in accordance with ISO 15037-2. 7.2 Constant radius test During this test procedure, the vehicle shall be steered such that it moves on
43、 a circular path at a constant speed. Repeat the procedure at successively faster speeds. The entire procedure should be repeated on paths of at least three different radii. A standard radius of 100 m should be used for one of the paths. The radii of the other paths should span the largest range pra
44、cticable. The significance of the results improves with increases in the range and number of radii. Whichever the radii chosen, the vehicle shall be steered such that the reference point of the first unit remains within 0,5 m of the intended circular path. For each radius chosen, conduct the test at
45、 several speeds. The first speed shall be the slowest practical speed. Choose successive speeds such that the increments of centripetal acceleration are not more than 0,5 m/s2. Where the data vary rapidly with centripetal acceleration, it could be useful to make smaller incremental changes. 7.3 Cons
46、tant speed, variable-steer angle test During this test procedure, the vehicle shall be driven at a constant speed and constant steer angle. Repeat the procedure at successively larger steer angles. The entire procedure should be repeated applying at least three different speeds. The standard speed s
47、hould be 50 km/h and additional speeds covering the broadest range practicable are also recommended. A test at a very slow speed is desirable. The significance of the results improves with increases in the range and number of speeds. For each test run, maintain the average speed within a tolerance o
48、f 2 km/h of the selected speed. A deviation of the vehicle speed of 3 km/h from the selected speed is permissible. For each test speed, conduct tests at several levels of constant steer angle. The first steer angle shall be the smallest practical deflection from the straight-ahead position. Choose s
49、uccessive steer angles such that the increments of centripetal acceleration are no more than 0,5 m/s2. At slower speeds, where large changes of steer angle produce little change in centripetal acceleration, it could be useful to make smaller incremental changes. 7.4 Common test conditions For each test, maintain the steering-wheel position and the vehicle speed as constant as possible during the acquisition of the data. Take data for at least 3 s at each steady-state centripetal acceleration. During this
