
AutoDyn
Operators Manual
Section 9 - Page 20
CH9 AutoDyn Description of the Config File.fm
Channel 53 - WhlSlp
(C57-C10)/C10*100
Channel 53 is used to estimate the wheel slip that occurs during a test. It
takes the difference between the wheel speed measured by the optical
tachometer in Channel 57 and the roll speed in Channel 10. This
difference is converted into a percent slip number. The slip value will
usually be low (less than 1%) at low rates of acceleration or at constant
speed. Under high acceleration or deceleration, some slip will appear
(less than 5%). If the slip is greater than zero at low loads, it is probable
that the tire diameter information used by Channel 57 is incorrect for the
vehicle. The tire diameter information comes from the specifications in
Channel 84. Change the tire diameter until the average slip is zero at
constant speed and no load. This is the effective rolling diameter of the
tire. Use the
Tir_Dia
test profile to facilitate obtaining the correct tire
diameter.
Channel 54 - Rv/mph
C125/C10
Rv/kmh
C125/C10
Channel 54 calculates the ratio of the engine speed to the roll speed
during a test. This ratio is useful for observing potential wheel slip, clutch
slip, or tire slippage during changes in speed. During fast transients,
some change in the ratio can also be introduced if there are different data
filtration rates on the engine tachometer versus the roll speed, however,
this would not be the normal condition.
Channel 55 - OvrRat
C79*C80*81
Channel 55 calculates the overall ratio of all gears from crankshaft to the
driven wheel of the vehicle under test. Engine ratio, transmission ratio,
and final drive ratio are multiplied together to obtain the overall ratio.
Channel 56 - WhelRv
C12*60
Channel 56 is used to calculate the wheel rpm based on the optical
tachometer signal from Channel 12. Channel 56 is used by Channel 57 to
calculate the actual wheel speed in miles per hour
[km/h]
from the optical
tachometer input.
Channel 57 - WhlSpd
mph = (C56*C84/12*3.1416*60/5280)
km/h = (C56*C84*3.1416*60/100000)
Channel 57 is used to calculate the wheel speed in miles per hour
[km/h]
from the optical tachometer input on Channel 12 and calculations in
Channel 56. Channel 84, the tire diameter, is used to convert the wheel
rpm to miles per hour
[km/h]
.
Channel 58 - WhRvPm
(C10/60)*(5280/(C84*0.2618))
(C10/60)*(1000/(C84*3.14/1000))
Channel 58 calculates the wheel revolutions per minute using the roll
speed (C10) and tire diameter (C84). The constant 0.2618 equals Pi
divided by 12 and is used to simplify the equation for WinDyn. Channel 58
can then be used to derive engine speed in channel 125 without using
any type of sensor.
Содержание AutoDyn
Страница 4: ...AutoDyn Operators Manual Section 1 Page 4 AutoDyn Cover fm...
Страница 5: ...1 General Information...
Страница 10: ...S Y S T E M O V E R V I E W Section 2 Page 1 2 System Overview...
Страница 24: ...P A C K A G I N G A N D H A N D L I N G Section 3 page 1 Packaging and Handling 3...
Страница 29: ...T E S T A R E A R E Q U I R E M E N T S Section 4 page 1 4 Test Area Requirements...
Страница 40: ...I N S T A L L A T I O N Section 5 Page 1 5 Installation...
Страница 55: ...6 System Operation...
Страница 60: ......
Страница 78: ...H A N D H E L D C O N T R O L L E R Section 7 Page 1 7 Handheld Controller...
Страница 104: ...8 Theory Of Testing...
Страница 114: ...Theory Of Testing Volume 2 9 10 04 Section 8 Page 13 Figure 8 1 Frontal Area Coefficient of Drag US...
Страница 115: ...AutoDyn Operators Manual Section 8 Page 14 Theory Of Testing fm Figure 8 2 Frontal Area Coefficient of Drag Metric...
Страница 123: ...9 Description of the Configuration File...
Страница 172: ...20 Service and Calibration...
Страница 178: ...S E R V I C E A N D C A L I B R A T I O N Section 20 page 7 20 2 Maintenance record...
Страница 193: ...A General Testing Information Appendix...
Страница 205: ...B Fundamental Concepts to Obtaining Superior Repeatability Appendix...