1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 11026:2010Heavy commercial vehicles andbuses Test method for rollstability Closing-curve testBS ISO 11026:2010 BRITISH STANDARDNational forewordThis British Standard is th
2、e UK implementation of ISO 11026:2010.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 publication does not purport to include all the n
3、ecessaryprovisions of a contract. Users are responsible for its correctapplication. BSI 2010ISBN 978 0 580 66380 2ICS 43.080.01Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy C
4、ommittee on 30 September 2010.Amendments issued since publicationDate Text affectedBS ISO 11026:2010Reference numberISO 11026:2010(E)ISO 2010INTERNATIONAL STANDARD ISO11026First edition2010-07-01Heavy commercial vehicles and buses Test method for roll stability Closing-curve test Vhicules utilitaire
5、s lourds et autobus Mthode dessai de stabilit au renversement Essai en courbe se fermant BS ISO 11026:2010ISO 11026:2010(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file may be printed or viewed but shall not be edited unless the t
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10、Web www.iso.org Published in Switzerland ii ISO 2010 All rights reservedBS ISO 11026:2010ISO 11026:2010(E) ISO 2010 All rights reserved iiiContents Page Foreword iv Introduction.v 1 Scope1 2 Normative references1 3 Terms, definitions and symbols 1 4 Principle1 5 Measuring equipment .2 6 Variables.2
11、7 Test conditions 3 7.1 General .3 7.2 Test vehicle 3 8 Test method .4 8.1 Initial driving condition.4 8.2 Performance of the steering procedure4 9 Data evaluation 5 9.1 General .5 9.2 Average jerk .5 9.3 Validity criteria.5 9.4 Characteristic values 5 9.5 Other values of interest 5 Annex A (normati
12、ve) Test report General data and test conditions .6 Annex B (informative) Example of calculating a test path7 Annex C (informative) Examples of sequencing closing-curve tests .9 BS ISO 11026:2010ISO 11026:2010(E) iv ISO 2010 All rights reservedForeword ISO (the International Organization for Standar
13、dization) 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 the right to
14、 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. International Stan
15、dards 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. Publication as an Int
16、ernational 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 rights. ISO 11026
17、 was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 9, Vehicle dynamics and road-holding ability. BS ISO 11026:2010ISO 11026:2010(E) ISO 2010 All rights reserved vIntroduction The main purpose of this International Standard is to provide repeatable and discriminatory test
18、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 environment, constitutes a closed-loop system that is unique. The task of evaluating the dynamic behaviour is therefore very difficult
19、since the significant interaction of these drivervehicleenvironment elements are each complex in themselves. A complete and accurate description of the behaviour of the road vehicle must necessarily involve information obtained from a number of different tests. Since this test method quantifies only
20、 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 the overall dynamic behaviour. Moreover, insufficient knowledge is available concerning the relationship between overall vehicle dynamic
21、 properties and accident avoidance. A substantial amount of work is necessary to acquire sufficient and reliable data on the correlation between accident avoidance and vehicle dynamic properties in general and the results of these tests in particular. Consequently, any application of this test metho
22、d for regulation purposes will require proven correlation between test results and accident statistics. BS ISO 11026:2010BS ISO 11026:2010INTERNATIONAL STANDARD ISO 11026:2010(E) ISO 2010 All rights reserved 1Heavy commercial vehicles and buses Test method for roll stability Closing-curve test 1 Sco
23、pe This International Standard specifies an open-loop test method for determining the roll stability of a vehicle negotiating a curve on dry surface. It applies to heavy vehicles, that is commercial vehicles, commercial vehicle combinations, buses and articulated buses as defined in ISO 3833 (trucks
24、 and trailers with maximum weight above 3,5 t and buses and articulated buses with maximum weight above 5 t, according to ECE and EC vehicle classification, categories M3, N2, N3, O3 and O4). The method is intended for vehicles equipped with electronic roll stability control systems. 2 Normative ref
25、erences The following referenced documents are indispensable for the application 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 d
26、efinitions ISO 8855, Road vehicles Vehicle dynamics and road-holding ability Vocabulary ISO 15037-2:2002, Road vehicles Vehicle dynamics test methods Part 2: General conditions for heavy vehicles and buses 3 Terms, definitions and symbols For the purposes of this document, the terms, definitions and
27、 symbols given in ISO 15037-2, ISO 8855 and the following apply. 3.1 jerk rate of change of lateral acceleration 3.2 steady-state rollover threshold maximum magnitude of lateral acceleration that a vehicle can sustain during steady-state cornering on a flat and level surface without rolling over 4 P
28、rinciple The objective of this test method is to determine the effect of roll stability control on the roll stability of a vehicle travelling at constant longitudinal velocity on a path with a constantly increasing curvature, a closing curve. Also, effects on the yaw stability will be considered. Th
29、e initial state for the test is driving in a straight line at constant longitudinal velocity. BS ISO 11026:2010ISO 11026:2010(E) 2 ISO 2010 All rights reservedThe path is defined by the curvature rate, kc, which gives the curvature, , along the path: cks = where s is the distance along the path. At
30、constant longitudinal velocity, VX, the jerk, ka, is constant. 3acXkkV= The path can be expressed in Cartesian coordinates in the earth-fixed system as follows: () ()Ecos dXs s=() ()Esin dYs s=where is the course angle, calculated as follows: 2a3Xd2ks sV= The severity of the test depends both on the
31、 jerk and on the longitudinal velocity. Higher velocity on a path with a certain jerk is more demanding than a lower velocity on another path with the same jerk. Thus, varying the jerk by changing the velocity on a given path is not identical to changing the path while maintaining the velocity. 5 Me
32、asuring equipment The measuring equipment, transducer installation and data processing shall be in accordance with ISO 15037-2. 6 Variables The variables of motion used to describe the behaviour of the vehicle shall be related to the intermediate axis system (X, Y, Z) of the first vehicle unit (see
33、ISO 8855). For the purpose of this International Standard, the location of the reference point is at ground level in the plane of symmetry and at the longitudinal position of the first axle of the first vehicle unit. The following variables shall be determined for compliance with this International
34、Standard: longitudinal velocity, VX; lateral acceleration, aY; indication of intervention of the electronic stability control system; indication of roll instability, which may be indicated by the outriggers touching the ground if they are mounted at a height that corresponds to roll instability; ind
35、ication of yaw instability of vehicle combinations, which may be indicated by the engagement of the anti-jackknife device if it is mounted in such a way that it allows an articulation angle of at least 45. BS ISO 11026:2010ISO 11026:2010(E) ISO 2010 All rights reserved 3NOTE Determination of lateral
36、 acceleration is most important prior to intervention of the stability control system. During this period, vehicle behaviour is likely to be sufficiently quasi-static to allow determination of lateral acceleration from the product of yaw velocity and longitudinal velocity. The following variables sh
37、ould also be determined: steering-wheel angle, H; yaw velocity, ; articulation angles between vehicle units, I; brake pressures of interest, pB; rotational velocity of wheels, i; retarder operation; engine-torque demand; engine-torque actual; sideslip angle at the first rear axle of the first vehicl
38、e unit; longitudinal acceleration, aX. Typical operating ranges of the variables to be determined for this International Standard are shown in Table 1 and in ISO 15037-2. Table 1 Variables, typical operating ranges and recommended maximum errors of variables not listed in ISO 15037-2 Variable Typica
39、l operating rangeRecommended maximum error of the combined transducerrecorder system Brake pressure in air systems 0 to 1 500 kPa 15 kPa Brake pressure in hydraulic systems 0 to 30 MPa 0,3 MPa Rotational velocity of wheels 0 to 4 000 /s 5 /s 7 Test conditions 7.1 General The test conditions specifie
40、d in ISO 15037-2 apply. In addition, 7.2 applies. 7.2 Test vehicle 7.2.1 Safety equipment Anti-rollover outriggers should be used when executing the test, especially if the test is used to investigate the performance limits of the stability control system. In the case of vehicle combinations, anti-j
41、ackknifing devices should be used. BS ISO 11026:2010ISO 11026:2010(E) 4 ISO 2010 All rights reserved7.2.2 Loading conditions The standard loading condition is maximum loading with the centre of gravity of the load at least high enough to cause rollover during a test if the stability control system w
42、ere disabled. The height of the centre of gravity of the load of the vehicle shall be reported. The steady-state rollover threshold should also be reported. Additional loading conditions are recommended. 8 Test method 8.1 Initial driving condition The initial driving condition for the test shall be
43、driving straight ahead as specified in ISO 15037-2. 8.2 Performance of the steering procedure The vehicle shall be steered in such a way that its reference point follows a path that starts with a straight line and ends with a circular curve. The transition between the straight ahead part and the cir
44、cular part shall give a constant jerk, ka(m/s3), at constant longitudinal velocity, VX(m/s). The curvature of the circular part, 1/Ri, shall give a lateral acceleration, at the test velocity, that exceeds the steady-state rollover threshold of the vehicle by at least 50 %. The accelerator pedal shal
45、l be kept constant throughout the test. Cruise control shall not be engaged. For manual transmissions, a gear position that gives an engine speed as close as possible to the maximum number of revolutions per minute shall be chosen. In order to avoid inappropriate self-calibration of the electronic v
46、ehicle stability control system, and to ensure that system parameters have achieved a steady state, test runs should be interspersed with sufficient periods of “normal” driving. Normal driving includes straight ahead driving, moderate turning in both directions and moderate accelerations and deceler
47、ations. For each combination of jerk and longitudinal velocity, the test shall be conducted at least three times, both in left- and right-hand turns. A test run is finished when the vehicle has reached steady state on the circular curve or when roll or yaw instability has occurred. The closing-curve
48、 part of the path, as a function of the length coordinate s (m) along the path, is defined in Cartesian coordinates with the following equations. s is an incremental step along the path. It should not exceed 0,01 m in order to get sufficient accuracy. m2ami3X0cos2iikXssV=m2ami3X0sin2iikYssV=Annex B
49、shows an example of calculating a path. In order to find the value of jerk at which the vehicle eventually rolls over at a given test velocity, the jerk shall be increased in steps by changing the path. To get a complete understanding of the ability of the roll stability system to prevent rollovers, as a function of jerk and velocity, tests should be carried out with different velocities. Annex C shows various examples of seque
