A Swept Sine event simulates a vehicle driving at a constant speed with a sinusoidal
steering input of constant magnitude but increasing frequency applied.
Output Requests are included to measure the vehicle state variables, tire forces, and tire
state variables. The Altair Driver steers the vehicle and maintains constant speed. A plot
template is available to plot the results.
This test is used to measure the dynamic response of the vehicle to sinusoidal steering
input. Figure 1.
The parameters available in the Swept Sine event are detailed in the following table:
Parameter
Description
Amplitude
Amplitude of the steering input (degrees).
Frequency Rate
The rate of change of frequency (hz/sec) of the sine wave function applied to
the steering wheel.
Minimum frequency
The minimum (initial) frequency sine wave that is applied to the steering
wheel.
Maximum frequency
The maximum (final) frequency sine wave that can be applied to the steering
wheel.
Start time
The start time of the sine wave steering function application to the steering
wheel.
Velocity
The constant speed that the vehicle attempts to maintain during the
event.
End Time
End time of the simulation. End time is calculated using the start time, the
frequency rate, and the max and min frequencies. All frequencies from min to max
are run.
Print interval
Data is output to the plot files and graphics file at this time interval
(seconds).
Figure 2. Swept Sine Event
Reference
ISO +7401-2003 - Road vehicles — Lateral transient response test methods — Open-loop test
methods.
