GB/T 40499-2021 PDF in English
GB/T 40499-2021 (GB/T40499-2021, GBT 40499-2021, GBT40499-2021)
| Standard ID | Contents [version] | USD | STEP2 | [PDF] delivered in | Name of Chinese Standard | Status |
| GB/T 40499-2021 | English | 365 |
Add to Cart
|
0-9 seconds. Auto-delivery.
|
General condition of vehicle dynamics test for heavy vehicles and buses
| Valid |
Standards related to (historical): GB/T 40499-2021
PDF Preview
GB/T 40499-2021: PDF in English (GBT 40499-2021) GB/T 40499-2021
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 43.020
CCS T 00
General condition of vehicle dynamics test for heavy
vehicles and buses
(ISO 15037-2:2002, Road vehicles - Vehicle dynamics test methods -
Part 2: General conditions for heavy vehicles and buses, MOD)
ISSUED ON: AUGUST 20, 2021
IMPLEMENTED ON: MARCH 01, 2022
Issued by: State Administration for Market Regulation;
Standardization Administration of the People’s Republic of
China.
Table of Contents
Foreword ... 3
1 Scope ... 6
2 Normative references ... 6
3 Terms and definitions ... 6
4 Variables ... 6
5 Measurement equipment ... 7
6 Test conditions ... 11
7 Test preparation ... 13
Appendix A (Informative) Structural changes between this document and ISO
15037-2:2002 ... 17
Appendix B (Normative) Test report - General data ... 19
Appendix C (Informative) Sensor and its installation ... 23
Appendix D (Informative) Analog signal filtering: Butterworth filter ... 29
Appendix E (Normative) Test conditions ... 31
General condition of vehicle dynamics test for heavy
vehicles and buses
1 Scope
This document specifies methods of vehicle dynamics test for heavy vehicles
and buses.
This document applies to M1, M2, M3, N2, N3 vehicles whose total mass is more
than 3 500 kg.
2 Normative references
The contents of the following documents constitute the indispensable clauses
of this document through normative references in the text. For dated references,
only the version corresponding to that date is applicable to this document; for
undated references, the latest version (including all amendments) is applicable
to this document.
GB/T 12549-2013, Terms and Definitions for Vehicle Controllability and
Stability (ISO 8855:2011, NEQ)
3 Terms and definitions
The following terms and definitions are applicable to this document.
3.1
Vehicle unit
A unit of vehicles that are connected by a yaw articulation.
Note: The number of vehicle units is one more than the number of yaw
articulations.
4 Variables
4.1 Reference frame
The motion variables recorded in the test shall meet the definition of coordinate
system in GB/T 12549-2013. The origin of the coordinate is usually taken at the
Hz. In the frequency range of 0 Hz ~ 2 Hz, the amplitude error shall be less than
±0.5%. All analog signals shall be processed with filters of the same phase
characteristics, so as to ensure that the time delay caused by filtering is the
same.
Note: In order to save the low frequency signal, DC coupling shall be adopted
as the signal. Since the analog signal filtering process of different
frequency components will be phase shifted, it is recommended to use
the digital signal processing method that is described in 5.3.3.
5.3.3 Aliasing error and anti-aliasing filter
5.3.3.1 Preparations for analog signal processing include: selecting the
sampling frequency and filter amplitude attenuation characteristics to avoid
aliasing errors, and the phase lag and time delay characteristics of the filter.
5.3.3.2 Contents to be considered for sampling and digitization:
a) The pre-sampling amplification ratio that ensures the smallest digitization
error;
b) The number of bits per sampling;
c) The number of samples per cycle;
d) Sampling and holding amplifier;
e) Sample space;
f) For other digital filters without phase shift, the selection of passband,
stopband, attenuation, allowable ripple, and the correction of filter phase
lag shall be considered.
5.3.3.3 In order to achieve an acquisition accuracy of ±0.5% for the overall data,
the above influencing factors shall be considered comprehensively.
5.3.3.4 For the attenuation and phase shift information of the Butterworth filter,
see Appendix D. In order to avoid uncorrectable aliasing errors, the analog
signal shall be properly filtered before sampling and digitization. The filter order
and its passband shall be selected according to the frequency range of interest
and the signal flatness requirements at the corresponding sampling frequency.
The minimum filtering characteristics and minimum sampling frequency shall
meet:
a) In the frequency range of 0 Hz ~ 2 Hz, the maximum attenuation of the
analog signal shall be less than the resolution of signal digitization;
b) At half the sampling frequency (i.e., Nyquist frequency or folding
frequency), the size of all frequency components of the signal and noise
shall be reduced to less than the digital resolution.
Example: For a resolution of 0.05%, the filter attenuation is less than 0.05% in
the 2 Hz range. For all frequencies above one-half the sampling
frequency, the attenuation is greater than 99.95%.
5.3.3.5 The anti-aliasing filter is recommended to be fourth-order or higher; see
Appendix D. Anti-aliasing filter shall be used; excessive analog signal filtering
shall also be avoided. In addition, all filters shall have the same phase
characteristics, so as to ensure that the time delay difference between the
signals meets the requirements of time domain measurement accuracy.
Note: Because when the measured variable amplitude is multiplied, the phase
shift and the corresponding time delay will increase, so, when the
measured variable is multiplied to form a new variable, the phase shift
shall be paid special attention. By increasing the cutoff frequency f0 of
the filter, the phase shift and time delay can be reduced.
5.3.4 Sampling and digitization
5.3.4.1 At 2 Hz, the amplitude change of the signal per millisecond can reach
3%. In order to limit the dynamic error that is caused by the analog input change
exceeding 0.1%, the sampling or digitization time shall be less than 32 μs. The
data of each pair or group of to-be-compared samples shall be collected at the
same time or in a short enough time.
5.3.4.2 Digitization shall adopt a system, of which the resolution is 12-bit or
higher (±0.05%) and the accuracy is 2 LSB (±0.1%). The amplification of the
analog signal before digitization shall be guaranteed: in the digitization process,
the comprehensive error caused by the limited resolution and the inaccuracy of
digitization shall be less than 0.2%.
5.3.5 Digital filter without phase shift
For the filtering that is used to evaluate the data, the digital filter without phase
shift (zero phase shift) shall have the following characteristics (see Figure 1):
-- The range of the passband shall be 0 Hz ~ 2 Hz;
-- The stop band shall start between 6 Hz ~ 10 Hz;
-- The passband filter gain shall be 1 ± 0.005;
-- The stop band filter gain shall be ±0.01.
The wind speed of the surrounding environment during the test shall not exceed
5 m/s. For each test, the test report shall record the climatic conditions during
the test; see Appendix E.
6.4 Test vehicle
The basic data information of the test vehicle shall be recorded in the test report
in Appendix B. For any changes in vehicle parameters (such as load), the basic
data information shall be recorded again.
6.5 Tires
6.5.1 The tires shall be selected and installed on the test vehicle according to
the manufacturer's instructions. If the tire manufacturer does not clearly indicate,
the tire shall be run-in at least 150 km on the tested car or similar car, but it
must be ensured that there is no excessive use, such as emergency braking,
rapid acceleration, sharp turns, road shoulder pressure. After running-in, the
tire shall be kept in the same position for testing.
6.5.2 The tire tread depth (including the entire width of the tire contacting the
ground and the entire tire surface) shall be more than 90% of the initial tire tread
depth.
6.5.3 The production date of the tire shall be recorded in the test conditions;
see Appendix E; the test tire shall not exceed one year from the production date.
6.5.4 The tires shall be inflated according to the pressure corresponding to the
test environment temperature that is specified by the automobile manufacturer.
The tire cold inflation pressure shall meet the technical requirements of the
vehicle; the error shall not exceed 10 kPa.
6.5.5 The tire pressure and the depth of the tire tread pattern before preheating
shall be recorded in the test report; see Appendix E.
6.5.6 In addition to the basic tire conditions, tests can also be carried out under
other conditions. The specific details shall be recorded in the test report; see
Appendix E.
6.6 Key components
6.6.1 The model and type of key components that affect the performance test
of the entire vehicle and the design parameters that affect the test (such as
shock absorber parameters and suspension geometric parameters) shall meet
the manufacturer's instructions. Any data that deviates from the manufacturer's
instructions shall be recorded in the basic information; see Appendix B.
6.6.2 The leveling system that is suspended on the chassis and the cab has an
impact on the response, and shall be disabled in the steady state and step-input
tests.
6.7 Loading conditions
6.7.1 General conditions
6.7.1.1 The total mass of the test shall not exceed the maximum total mass and
the maximum axial load that are specified by the manufacturer; the total mass
and the centre-of-gravity position (longitudinal, lateral, vertical) shall be stated.
6.7.1.2 In order to test the vehicle mass, center of gravity position and moment
of inertia, it shall be close to the design; its increased load shall be evenly
distributed; the wheel load shall be measured and recorded in the test report.
See Appendix B.
6.7.2 Maximum loading condition
The maximum loading condition refers to the condition that the total mass of
the tractor or trailer is equal to the complete vehicle kerb mass plus the
designed maximum loading mass, or the state where the test vehicle is in the
designed maximum total mass, and at the same time, it shall be ensured that
the load on any axle does not exceed the maximum axial load of standard
requirements. The height of center of gravity of the test vehicle and the mass
distribution of the additional load shall reflect the application of the test vehicle.
The maximum loading condition is the standard test condition.
6.7.3 Minimum loading condition
The minimum loading condition of heavy vehicles and buses refers to the curb
weight of each unit plus the mass of the test equipment. For those that the
traction unit should be added with the driver's mass, the mass of an equipment
operator or observer can be added as needed. The minimum loading condition
is optional.
6.7.4 Other loading conditions
Other loading conditions can be used to represent special transportation
conditions.
7 Test preparation
7.1 Preheating
Before the start of the test, all relevant parts of the motor vehicle shall be
preheated, so that its temperature can reach a temperature representative of
Appendix C
(Informative)
Sensor and its installation
C.1 Overview
Sensors (including commercial and customized) are mainly used to measure
required and optional variables. If the sensor cannot directly measure the
required variable, the sensor signal shall be appropriately adjusted to obtain
this variable on the basis of ensuring accuracy.
Since there are many types of test instruments, each type of equipment used
shall be recorded; the installation location of the equipment on the motor vehicle
shall be recorded on the test data table (see Appendix B).
The sensor error requirements for various directly measured variables are
shown in the following clauses. The percentage error of the variable that is
calculated from the output signals of several sensors can be obtained by
dividing the differential value of the calculated variable by the variable.
C.2 Steering wheel angle
Typical sensors are multi-turn potentiometers or digital photoelectric encoders,
which are connected to the rear of the steering wheel through gears or
connected to the "additional steering wheel".
C.3 Longitudinal velocity
The longitudinal velocity sensor shall be installed as close as possible to the
reference point. In the process of data processing, the installation position of
the speed sensor shall be recorded, and necessary signal corrections shall be
made to obtain the reference point longitudinal velocity. The typical sensor is a
five-wheel instrument whose accuracy is 0.2 km/h; a "non-contact" speed
sensor that is based on optics or Doppler principle. The speed sensor based on
optics has an accuracy of 0.1 km/h; the speed sensor based on Doppler has an
accuracy of 0.5 km/h. The steady-state signal of the five-wheel instrument is
very close to the horizontal velocity, while the optical sensor measures the
longitudinal velocity (the component of the horizontal velocity in the X direction
is equal to the product of the horizontal velocity and the cosine of the slip angle).
Another alternative method of measuring longitudinal velocity is to use the
Global Navigation Satellite System (GNSS) (see C.11).
C.4 Side velocity and sideslip angle
The two-way speed sensor based on the optical principle that is installed
according to the product manual can directly measure the side velocity of a
given point. The installation location of the sensor shall be recorded. The side
velocity of any other point can be obtained by interpolation or extrapolation by
two side velocity sensors, or by the product of the side velocity of the measuring
point plus the yaw velocity AND the distance between the desired point and the
measuring point. The slip angle is obtained by dividing the side velocity by the
tangent of the longitudinal velocity. The commercial two-way speed sensor full
scale is ±10 m/s, the steady-state full scale accuracy is ±1%.
The side velocity can also be obtained by the integral of the difference by
subtracting the side acceleration (corrected by position, roll angle and surface
inclination errors) by the product of the longitudinal velocity and the yaw velocity;
then, the side slip angle can be calculated. Because the net acceleration error
(including zero offset) will accumulate, this method is only suitable for short-
term testing.
C.5 Angular velocity
The yaw velocity, roll velocity and pitch velocity can be directly measured by
the angular velocity sensor that is installed in accordance with the product
manual. The traditional angular velocity sensor refers to a gyroscope. In general,
good gyroscope performance includes: in the range of 1/2 full scale, the linearity
is ±0.2% ~ ±0.5% of full scale; in the range of 1/2 to full scale, the linearity is
±1% ~ ±2% of full scale; the cross sensitivity is 0.04%; the threshold is ±0.05%
of full scale; the hysteresis is 0.15% of full scale. Angular velocity sensors based
on Coriolis acceleration, optical fiber, laser or other physical principles have
been commercialized. They usually have the following characteristics: the
linearity is ±0.1% ~ 1% of full scale, the threshold sensitivity is 0.01%; the
hysteresis is zero.
The angular velocity sensor is usually fixed on the motor vehicle. Therefore,
they measure the yaw velocity of the ground plane multiplied by the cosine of
the vehicle roll angle during steady-state steering. In order to obtain the yaw
velocity of the ground plane, the vehicle roll angle and pitch angle shall be
corrected.
If the sideslip angle sensors are installed on the front axle and the rear axle at
the same time, the yaw velocity of the vehicle in the ground plane can be
calculated by dividing the difference between the side velocity of the front axle
and the rear axle by the longitudinal distance between the two sensors.
C.6 Side acceleration
In most working conditions, especially in steady-state conditions, the focus is
on centripetal acceleration. Typically, the actual measured quantity is side
Note: The side acceleration is the component of the acceleration vector at this
point in the Y direction.
C.7 Vehicle angle
The vehicle roll angle and pitch angle relative to the direction of gravity can be
measured by a two-axis gyroscope; a non-reference gyroscope or a gravity
reference vertical gyroscope can be selected. The free gyroscope has a frame
structure and shall be locked on its shell when not measuring. When the frame
structure is unlocked, it remains unchanged in the inertial space and can
measure the angle of car movement. The free gyroscopes can be used to
measure roll and yaw angles, or roll and pitch motions. By actively controlling
the action of the slow-rotating torque motor, the vertical gyroscope is "upright"
with respect to the vertical direction of gravity. Neither of the above two types
of gyroscopes can obtain the required measured acceleration under long-term
stable steering. According to the product manual, the free gyroscope and the
vertical gyroscope of failure vertical system "drift" at a maximum speed of 0.5°
~ 1° per minute; the vertical gyroscope that is effectively installed a vertical
system will search for "vertical line of sight" at a rate of 2° ~ 5° per minute, which
is the vector sum of gravity and side acceleration. When there is no side
acceleration, the vertical accuracy of the vertical gyroscope can reach ±0.15° ~
±0.1°.
The roll and pitch angles of the vehicle relative to the road can be measured by
the following methods:
a) The angle measurement sensor shall be installed on the roll and pitch
balance frame of the side-sliding vehicle.
b) Through ultrasonic or optical sensors, measure the change in the vertical
distance from a reference point located in front of, behind or on the side
of the vehicle to the ground. It’s sufficient for ultrasonic or optical sensors
to achieve a measurement accuracy of 0.5 mm. The road surface is far
from flat, and its roughness cannot be ignored and it is also obvious. Three
automobile sensors will define a plane, which is used for calculating the
pitch and roll angles relative to the road. It is recommended to install the
ultrasonic sensor or optical sensor as far as possible, so as to improve the
measurement accuracy.
c) The measurement of the wheel runout relative to the sprung mass mainly
considers the influence of the suspension connecting rod (the method
does not consider the tire deformation).
In each of the above methods, when there are no other constraints in the test
experiment, the accuracy of its description can be achieved. In order to obtain
the vehicle roll angle and pitch angle relative to the ground plane, the
measurement signal shall be corrected by the angle of the road plane relative
to the horizontal plane.
The amount of change of the vehicle's roll angle and pitch angle relative to the
initial test conditions can be measured by the integral measurement of the
angular velocity gyroscope signal. This method is only suitable for short-term
testing, because the entire signal including zero drift will be accumulated.
Note 1: For cars with a suspended cab or a separate cab, there will be two body
angles. One is the car body angle of the cab relative to the road surface,
and the other is the car body angle of the chassis relative to the road
surface.
Note 2: The roll angle which is obtained by measuring the vertical distance
change between the reference points on both sides of the vehicle with
respect to the road surface by ultrasonic sensors or optical sensors may
be different from the measurement results of other methods, which is
related to the roll stiffness of the car chassis. For motor vehicles with
independent chassis or those which are very long, this effect shall be
paid special attention to.
Depending on the end use, the road inclination angle shall be used to correct
the measured roll angle data relative to the road surface or the direction of
gravity.
C.8 Steering wheel moment
The steering wheel moment can be measured by a torque sensor that is
installed in accordance with the product manual, which mainly measures the
torque acting on the steering wheel relative to the axis of rotation. In some tests,
if the inertia of the steering wheel is inconsistent with the original vehicle, its
measurement results are inaccurate.
C.9 Wheel steering angle
The wheel steering angle relative to the sprung mass can be measured by an
angle sensor. The sensor, which is located between the sprung mass and the
steering knuckle assembly, is installed on the bearing of the wheel hub, and is
connected to the sprung mass by the constraints that allow front/rear, vertical
and camber movements; or it is measured by the linear displacement or angular
displacement sensor that is installed on the steering rod.
The front-wheel steering angle that is formed by suspension kinematics and
elastic kinematics can be calculated by subtracting the steering wheel angle
from the preceding vehicle steering angle, and dividing by the total steering
gear ratio.
......
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.
|