1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 17288-1:2011Passenger cars Free-steerbehaviourPart 1: Steering-release open-loop testmethodBS ISO 17288-1:2011 BRITISH STANDARDNational forewordThis British Standard is th
2、e UK implementation of ISO 17288-1:2011.It supersedes BS ISO 17288-1:2002 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee AUE/15, Safety related to vehicles.A list of organizations represented on this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
3、.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. BSI 2011ISBN 978 0 580 72766 5ICS 43.100Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under
4、 the authority of theStandards Policy and Strategy Committee on 31 March 2011.Amendments issued since publicationDate Text affectedBS ISO 17288-1:2011Reference numberISO 17288-1:2011(E)ISO 2011INTERNATIONAL STANDARD ISO17288-1Second edition2011-02-15Passenger cars Free-steer behaviour Part 1: Steeri
5、ng-release open-loop test method Voitures particulires Comportement volant libre Partie 1: Mthode dessai en boucle ouverte avec relchement du volant BS ISO 17288-1:2011ISO 17288-1:2011(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this fi
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10、+ 41 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 17288-1:2011ISO 17288-1:2011(E) ISO 2011 All rights reserved iiiForeword ISO (the International Organization for Standardization) is a worldwide federation o
11、f 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 be represented on that committee. In
12、ternational 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
13、the rules given in the ISO/IEC Directives, Part 3. 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
14、 by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this part of ISO 17288 may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 17288-1 was prepared by Technical
15、 Committee ISO/TC 22, Road vehicles, Subcommittee SC 9, Vehicle dynamics and road-holding ability. This second edition cancels and replaces the first edition (ISO 17288-1:2002), of which it constitutes a minor revision. ISO 17288 consists of the following parts, under the general title Passenger car
16、s Free-steer behaviour : Part 1: Steering-release open-loop test method Part 2: Steering-pulse open-loop test method BS ISO 17288-1:2011ISO 17288-1:2011(E) iv ISO 2011 All rights reservedIntroduction The main purpose of this part of ISO 17288 is to provide repeatable and discriminatory test results.
17、 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 since th
18、e significant interactions 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
19、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 prop
20、erties 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 method for
21、 regulation purposes will require proven correlation between test results and accident statistics. BS ISO 17288-1:2011INTERNATIONAL STANDARD ISO 17288-1:2011(E) ISO 2011 All rights reserved 1Passenger cars Free-steer behaviour Part 1: Steering-release open-loop test method 1 Scope This part of ISO 1
22、7288 specifies an open-loop test method for determining the free control stability of a passenger car as defined in ISO 3833, by measurement of the transient behaviour following steering release, starting from a steady-state cornering status. NOTE The open-loop manoeuvre specified in this part of IS
23、O 17288 is not representative of normal driving conditions, but is nonetheless 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
24、 applies. 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 15037-1:2006, Road vehicles Vehicle dynamics test m
25、ethods Part 1: General 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 for evaluating the ability of a vehicle to return to a straight path following steering-wh
26、eel release from a steady-state turn. The initial conditions are defined by a steady-state circular motion. During the test, the driver releases the steering wheel. The steering-wheel angle and the vehicle response are measured and recorded. From the recorded signals, characteristic values are calcu
27、lated. BS ISO 17288-1:2011ISO 17288-1:2011(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 ISO 8855): longitudinal velocity (vX); lateral acceleration (aY); yaw velocity ( );
28、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 using a multi-channel recording system. Typical operating ranges, and recommended maximum errors of the transducer and recor
29、ding system, are given in Table 1. Table 1 Variables, typical operating ranges and recommended maximum errors Variable Typical operating range Recommended maximum error of combined transducer-recorder system Longitudinal velocity 0 m/s to +50 m/s 0,3 m/s Lateral acceleration 15 m/s2to +15 m/s20,1 m/
30、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 general use. Many such instruments are developed by users. If any system error exceeds the recommended maximum valu
31、e, 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 comply with ISO 15037-1:2006, 4.2. For the steering-wheel angle, the additional requirements given in 6.2.1 of ISO
32、 15037-1:2006 shall apply. BS ISO 17288-1:2011ISO 17288-1:2011(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 conjunction with the original steering wheel of the vehicle. Alternatively, a replacement instru
33、mented 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 test report as given in Annex B of ISO 15037-1:2006. NOTE Free control behaviour is known to be sen
34、sitive 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 15037-1:2006, 4.3, apply. 7 Test conditions Test conditions shall be in accordance with ISO 15037
35、-1:2006, Clause 5. 8 Test procedure 8.1 Test report 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 details” and “Test method specific data”, respectively. 8.2 Warm-up The warm-up shall be carr
36、ied out in accordance with ISO 15037-1:2006, 6.1. 8.3 Starting conditions of the test The starting condition for the test is a steady-state circular motion at a prescribed level of lateral acceleration, aY0. The steady-state circular motion shall be in accordance with ISO 15037-1:2006, 6.2.3, except
37、 for the following: for the time interval from t1to t2, the standard deviation of the lateral acceleration shall not exceed 3 % of its mean value or 0,2 m/s2, whichever is higher. The standard longitudinal velocity shall be 100 km/h; it may vary by steps of 20 km/h. Where possible, the test should b
38、e conducted performing alternating left and right turns. The initial prescribed level of lateral acceleration aY0of 1 m/s2shall be incremented in steps of, nominally, 1 m/s2, until a limiting condition is reached (see 8.4). 8.4 Test execution From each starting condition, the driver shall suddenly r
39、elease the steering wheel at the reference point in time, t0 (see ISO 15037-1:2006, Figure 2), while maintaining the throttle constant and placing the vehicle in free control, so that its response is determined by its dynamic characteristics. Record test data from time t1for 1 s after the steering o
40、scillation is completely damped or until t0+ 5 s, whichever is shorter. The test should be repeated from starting conditions at incremented levels of lateral acceleration until vehicle response becomes divergent, or the limit of lateral adhesion is reached in the starting condition. BS ISO 17288-1:2
41、011ISO 17288-1:2011(E) 4 ISO 2011 All rights reserved9 Data analysis 9.1 General General data shall be presented in accordance with the test report given in ISO 15037-1:2006, Annexes A and B. The recorded time history of the relevant variables shall be displayed and examined visually. Results not co
42、nsidered representative shall be discarded. 9.2 Ratio between second and first peak of a given variable after steering-wheel release For each of the variables (see Figure 1) sideslip angular velocity, yaw velocity, and steering-wheel angle: a) evaluate the function f (aY0) = peak 2/peak 1, at each l
43、evel of initial lateral acceleration aY0; b) plot the function f (aY0) vs aY0; c) compute the linear regression (see Figure 2); d) calculate m, the slope of the linear regression; e) calculate q, the value of the linear regression at a lateral acceleration of 4 m/s2. NOTE Sideslip angular velocity i
44、s usually calculated by the formula: ()( )()()YXatttvt=where aY is the lateral acceleration of the vehicle; vXis the longitudinal velocity of the vehicle; is the yaw velocity of the vehicle; t is time. 9.3 Value of second peak of a given variable after steering-wheel release For each of the variable
45、s (see Figure 1) sideslip angular velocity, yaw velocity, and steering-wheel angle: a) evaluate the function f (aY0) = peak 2, at each level of initial lateral acceleration aY0; b) plot the function f (aY0) vs aY0; BS ISO 17288-1:2011ISO 17288-1:2011(E) ISO 2011 All rights reserved 5c) compute the l
46、inear regression (see Figure 2); d) calculate m, the slope of the linear regression; e) calculate q, the value of the linear regression at a lateral acceleration of 4 m/s2. Key t time, in seconds yaw velocity Hsteering-wheel angle sideslip angular velocity aPeak 1. bPeak 2. Figure 1 Peaks of variabl
47、es after steering-wheel release BS ISO 17288-1:2011ISO 17288-1:2011(E) 6 ISO 2011 All rights reservedKey aY0lateral acceleration, in m/s2 m slope of the linear regression q value of the linear regression at a lateral acceleration of 4 m/s2Figure 2 Typical aspect of functions of lateral acceleration
48、9.4 Delay of first peak of a given variable after t50(see Figure 3) For each of the variables (see Figure 1) steering-wheel angle, and lateral acceleration: a) evaluate the function f (aY0) = time delay of peak 1, at each level of initial lateral acceleration aY0; b) plot the function f (aY0) vs aY0
49、; c) compute the linear regression (see Figure 2); d) calculate m, the slope of the linear regression; e) calculate q, the value of the linear regression at a lateral acceleration of 4 m/s2. BS ISO 17288-1:2011ISO 17288-1:2011(E) ISO 2011 All rights reserved 7Key t time, in seconds Hsteering-wheel angle, in degrees aY0lateral acceleration, in m/s2a50 % of the initial level. Figure 3 Delay of first peak of steering-wheel angle and late
