ISO 10392:1992-06 pdf free download.Road vehicles with two axles – Determination of centre of gravity.
ISO 10392 specifies a method to determine the location of the centre of gravity of a road vehicle, as defined In ISO 3833. with two axles. Other procedures may exist and be uscd. employing more elaborate and sophisticated methods and equipment, such as tilt-tables and cradles.
2 Normative references
The following standards contain provisions which. through reference in this text, constitute provisions of ISO 10392. At the time 01 publication, the editions indicated were vaIid Al) standards are subject to revision, and parties to agreements based on ISO 10392 are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO marntain registers of currently valid International Standards
ISO 612:1978. Road vehicles — Dimensions of motor vehicles and towed vehicles — Terms and definitions.
ISO 3833:1977, Road vehicles — Types — Terms and definitions
ISO 8855 iggi. Road vehicles — Vehicle dynamics and road-holding ability — Vocabulary.
3 Test conditions
3.1 Operating and other liquids
The fuel tank shall be completely full lithe displacement of other liquids (operating and other) due to the inclination of the vehicle, as measured In clause 4. is considered significant, this shall be taken into account.
3.2 Loading conditions, suspension and mechanical parts
Any load shall be held in place to avoid displacement due to the inclination of the vehicle.
After loading the vehicle to the desired loading conditions. the wheel suspension shall be blocked to avoid changes in deflection due to the inclination of the vehicle. This may also apply to other vehicle components which could affect the test result due to flexible mounting
When lifting the vehicle, the gear-box shall be in neutral The parking-brake shalt be released; rolling of the wheels of one axle only shall be avoided by wedges or other means. The front wheels shall remain pointing straight ahead as far as possible.
4 MeasurIng procedure
4.1 With the vehicle hori7ontal, and In accordance with the dimensions given In ISO 612 and ISO 8855. measure and record;
. the wheelbase, left, in millimetres:
the wheelbase, right. In millimetres; ?. the track, front, in millimetres;
k. the track, rear, in millimetres;
m1, the wheel load, front left, In kilograms;
m2. the wheel load, front right. in kilograms:
m1, the wheel load, rear left, in kilograms; m4, the wheel load, rear right, in kilograms;
the static loaded radius’, front left, in mliii metres:
the static loaded radius”, front right, in millimetres:
r,,3, the static loaded radius”, rear left, in mullmetres;
r314, the static loaded rear right, In millimetres.
4.2 Lift one axle in steps (three or more steps are recommended). Record the axle load of the other axle and the lifting angle for each position, The maximum lifting angle depends upon the accuracy of the scale which Is used to measure the axle load it shall he large enough to provide the accuracy required in clause 5.
4.3 To take the hysteresis into account, lower the lifted axle by steps back to the level position and record axle loads and lifting angle as described as above.
4.4 Plot the axle loads and the tangent of the corresponding lifting angles and determine the mean value of axle load for a corresponding lifting angle
4.5 It is recommended that all the measurements be repeated lifting the other axle
4.6 It may also be desirable to determine the lifting angle from the wheelbase and the elevation of the wheels above the ground for each inclination position. In this case the change in tyre deformation caused by lifting one end of the vehicle shall be taken into consideration.
5 Accuracy of determined parameters
The following accuracies are required:
— Absolute axle load vatue ± 0.2 %
— Change In axle loads due to lifting (applies to scales, which do not
measure absolute loads, but changes
In loads): ± 2,5 Ofo
— Dimensions’ 2 000 mm: ± 1 mm
>2000mm: ±0,05 %
— Angles: ± I %
6 DetermInation of location of centre of gravity
6.1 Determination of coordinates in horizontal plane
6.1.1 Location of centre of gravity longitudinally
The horizontal distance between centre of front axle and centre ol gravity, CO’ in millimetres. Is determined by the equation
in,
where
m, = in3 + in4 (as defined in 41) — rear axle
load, in kilograms:
ifld=inl+fl12+?fl3+1fl4 (as defined in 4.1)
total mass of vehicle, in kilograms:
1=O,5(4, + (as defined in 4.1) wheelbase of the vehicle, in millimetres.
6.1.2 LocatIon of centre of gravity laterally
The horizontal distance between the longitudinal median plane of the vehicle and the centre of gravity (positive to the left), YcG’ in millimetres, is determined by the equation
where all symbols are as defined in 4.1.
6.2 Determination of height of centre of gravity above ground
6.2.1 Determination of axle load and lifting angle The following values are obtained from the plotted data by linear curve fitting:
in’, and in’, which are axle loads at front and rear respectively of the axle remaining on the ground while the vehicle Is inclIned
lithe corresponding lifting angle
6.2.2 Location of centr. of gravity above ground The height of the centre of gravity above ground, in millimetres, is determined by the equations:
1 Is as defined in 61.
For symbols not defined, see 41.
NOTE I in1 and m, may be measured directly it only the height of the centre of gravity Is required, in which case ,n, m7, in1 and in4 are not needed
7 Data presentation
Measured data and test results shall be presented in a test report as shown in annex B.