1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 17288-2:2011Passenger cars Free-steerbehaviourPart 2: Steering-pulse open-loop testmethodBS ISO 17288-2:2011 BRITISH STANDARDNational forewordThis British Standard is the
2、UK implementation of ISO 17288-2:2011.It supersedes BS ISO 17288-2:2004 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee AUE/15, Safety related to vehicles.A list of organizations represented on this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.T
3、his publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. BSI 2011ISBN 978 0 580 72767 2ICS 43.100Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under t
4、he authority of theStandards Policy and Strategy Committee on 31 March 2011.Amendments issued since publicationDate Text affectedBS ISO 17288-2:2011Reference numberISO 17288-2:2011(E)ISO 2011INTERNATIONAL STANDARD ISO17288-2Second edition2011-02-15Passenger cars Free-steer behaviour Part 2: Steering
5、-pulse open-loop test method Voitures particulires Comportement volant libre Partie 2: Mthode dessai en boucle ouverte avec impulsion au volant BS ISO 17288-2:2011ISO 17288-2:2011(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file ma
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10、22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2011 All rights reservedBS ISO 17288-2:2011ISO 17288-2:2011(E) ISO 2011 All rights reserved iiiContents Page Foreword.iv Introduction.v 1 Scope 1 2 Normative references1 3 Terms and definitions
11、 .1 4 Principle1 5 Variables.2 6 Measuring equipment2 7 Test conditions 3 8 Test procedure.3 9 Data analysis4 Bibliography13 BS ISO 17288-2:2011ISO 17288-2:2011(E) iv ISO 2011 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide federation of national s
12、tandards 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 be represented on that committee. International
13、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 Standards are drafted in accordance with the rules gi
14、ven 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 International Standard requires approval by at least
15、 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 17288-2 was prepared by Technical Committee ISO/TC 22,
16、 Road vehicles, Subcommittee SC 9, Vehicle dynamics and road-holding ability. This second edition cancels and replaces the first edition (ISO 17288-2:2004), of which it constitutes a minor revision. ISO 17288 consists of the following parts, under the general title Passenger cars Free-steer behaviou
17、r : Part 1: Steering-release open-loop test method Part 2: Steering-pulse open-loop test method BS ISO 17288-2:2011ISO 17288-2:2011(E) ISO 2011 All rights reserved vIntroduction The main purpose of this part of ISO 17288 is to provide repeatable and discriminatory test results. The dynamic behaviour
18、 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 since the significant interact
19、ion of these driver-vehicle-environment 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 one small part of the compl
20、ete 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 properties and accident avo
21、idance. 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 method for regulation purposes wi
22、ll require proven correlation between test results and accident statistics. BS ISO 17288-2:2011BS ISO 17288-2:2011INTERNATIONAL STANDARD ISO 17288-2:2011(E) ISO 2011 All rights reserved 1Passenger cars Free-steer behaviour Part 2: Steering-pulse open-loop test method 1 Scope This part of ISO 17288 s
23、pecifies a procedure for determining the free control stability of a passenger car as defined in ISO 3833, by measurement of the transient behaviour following steering pulse input, starting from a straight-ahead, steady-state status. NOTE The open loop manoeuvre specified in this part of ISO 17288 i
24、s not representative of normal driving conditions, but is useful for obtaining a measure of vehicle transient behaviour. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated
25、 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 15037-1:2006, Road vehicles Vehicle dynamics test methods Part 1: Genera
26、l conditions for passenger cars 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 3833 and ISO 8855 apply. 4 Principle This test is intended to evaluate the ability of the vehicle to return to a straight path following a steering pulse input from a str
27、aight-ahead, steady-state driving initial condition. Oscillation of the vehicle is initiated by the application of a single pulse steering input. This is followed by release of the steering wheel and a period during which the steering wheel is free. The steering-wheel angle and the vehicle response
28、are measured and recorded. From the recorded signals, characteristic values are calculated. BS ISO 17288-2:2011ISO 17288-2:2011(E) 2 ISO 2011 All rights reserved5 Variables 5.1 Reference system The provisions given in ISO 15037-1:2006, 3.1, apply. 5.2 Measurement Measure the following variables (see
29、 ISO 8855): a) longitudinal velocity (vX); b) lateral acceleration (aY); c) yaw velocity (); d) steering-wheel angle (H). 6 Measuring equipment 6.1 Description All variables shall be measured by means of appropriate transducers, and their time histories shall be recorded by a multi-channel recording
30、 system. Typical operating ranges, and recommended maximum errors of the transducer and recording system, are given in Table 1. Table 1 Variables, their typical operating ranges and recommended maximum errors Variable Typical operating range Recommended maximum error of the combined transducer and r
31、ecorder system Longitudinal velocity 0 m/s to +50 m/s 0,3 m/s Lateral acceleration 15 m/s2to +15 m/s20,1 m/s2Yaw velocity 50/s to +50/s 0,3/s Steering-wheel angle 360 to +360 2 for |H| u 180 4 otherwise Transducers for measuring some of the listed variables are not widely available and not in genera
32、l use. Many such instruments are developed by users. If any system error exceeds the recommended maximum value, this and the actual maximum error shall be stated in the test report given in Annex A of ISO 15037-1:2006. 6.2 Transducer installation 6.2.1 General The transducer installation shall compl
33、y with ISO 15037-1:2006, 4.2. For the steering-wheel angle, the additional requirements given in 6.2.2, below, shall apply. BS ISO 17288-2:2011ISO 17288-2:2011(E) ISO 2011 All rights reserved 36.2.2 Steering-wheel angle It is recommended that the steering-wheel angle be measured using transducers in
34、 conjunction with the original steering wheel of the vehicle. Alternatively, a replacement instrumented steering wheel may be used. In either event, care should be taken to avoid changing the mass centre, inertial properties or friction of the steering system. Any changes shall be recorded in the te
35、st report given in ISO 15037-1:2006, Annex B. NOTE Free control behaviour is known to be sensitive to the friction and inertia characteristics of the steering system. In addition, it is sensitive to the mass and mass offset of the steering wheel. 6.3 Data processing The provisions given in ISO 15037
36、-1:2006, 4.3, apply. 7 Test conditions Test conditions shall be in accordance with ISO 15037-1:2006, Clause 5. 8 Test procedure 8.1 General All details of the test shall be recorded in the test report specified in ISO 15037-1:2006, Annexes A and B, under “General comments and/or other relevant detai
37、ls” and “Test method specific data”, respectively. 8.2 Warm-up The warm-up shall be carried out in accordance with ISO 15037-1:2006, 6.1. 8.3 Starting conditions of the test The starting condition for the test is steady-state straight-ahead running motion at a prescribed longitudinal velocity vX. Th
38、e steady-state straight-ahead running motion shall be in accordance with ISO 15037-1:2006, 6.2.1. The test shall be conducted for a minimum of three longitudinal velocities. These shall include the standard longitudinal velocity of 100 km/h, and other velocities varied in steps of 20 km/h. 8.4 Test
39、execution From each starting condition, the driver shall apply the steering pulse input to a predetermined value and release the steering wheel immediately to place the vehicle in free control with its response determined by its dynamic characteristics. The throttle shall be maintained constant, eve
40、n though velocity can decrease. The test shall be conducted with an amplitude of steering-wheel angle sufficient to produce the initial lateral acceleration (aY0) of 1 m/s2. The test shall be repeated with incremented amplitude of steering-wheel angle peak Hp, such that lateral acceleration is incre
41、mented in steps of not more than 0,5 m/s2up to a level of at least 5 m/s2. See Figures 1 and 2. Referring to the example time history of steering-wheel angle shown in Figure 1, t0is the time, in seconds, at which the amplitude of steering-wheel angle first exceeds 10 % of its maximum amplitude Hp, a
42、nd tpis the time of maximum amplitude at which the steering wheel is released. The rise time of pulse input (tp t0) shall be 0,2 s 0,05 s. Test data are recorded from time tss 0,5 s until 1 s after the steering oscillation is completely damped or until t0+ 5 s, whichever is shorter. BS ISO 17288-2:2
43、011ISO 17288-2:2011(E) 4 ISO 2011 All rights reservedWhere possible, the test should be conducted in both left and right turning directions. Key t time, s Hp maximum amplitude of steering-wheel angle tptime of maximum amplitude of steering-wheel angle (at which steering wheel is released) tsspoint i
44、n time from which steady-state straight-ahead driving is recommended aFree steer control. b0,5 s to 0,8 s. Figure 1 Steering-wheel angle input 9 Data analysis 9.1 General General data shall be presented in the test report given in ISO 15037-1:2006, Annexes A and B. The recorded time history of the f
45、ollowing variables shall be displayed and examined visually. Results not considered to be representative shall be discarded: yaw velocity; steering-wheel angle; sideslip angular velocity. NOTE Sideslip angular velocity is usually calculated by the formula: ()( )()()YXatttvt=(1) BS ISO 17288-2:2011IS
46、O 17288-2:2011(E) ISO 2011 All rights reserved 5where vXis the longitudinal velocity of the vehicle; is the yaw velocity of the vehicle; aYis the lateral acceleration of the vehicle; t is time. 9.2 Damping and damping time of yaw velocity Referring to the example time history of yaw velocity shown i
47、n Figure 2, all amplitudes starting with the second peak shall be determined. Calculate the mean value of the amplitude ratios, r , using Equation (2): 21233412233445 11.2nnnnrn + +=+ + + (2) NOTE Each amplitude, ,nis an absolute value. 1nn +shall be at least 10 % of 12 +, or nshall be the last ampl
48、itude of the recorded time period of 5 s. When the amplitude of third peak, 3 , is too small to be determined clearly, or 2is smaller than 10 % of 1 , calculate r using Equation (3): 12r=(3) Calculate the damping of yaw velocity, D, using Equation (4): ()22lnlnrDr=+(4) Calculate the damping time of
49、yaw velocity, T0,1 which indicates the duration of yawing oscillation (i.e. the time period required to decrease the yaw velocity within 10 % level of peak 1) using Equation (5): 0,1ln 10TD =(5) where ()()2111nntt D=(6) For each of the variables damping of yaw velocity, and damping time of yaw velocity: a) evaluate the functions f (aY0) = D and f
