Calculating The Maximum Time Duration Of A Movement File; Vehicle Description Files (Used For Smoothening) - R&S SMW-K44 User Manual

Satellite Navigation
For information on the impact of the used resolution on the number of possible way-
points, see
File",
A.1.6 Calculating the Maximum Time Duration of a Movement File
The R&S SMW loads the movement and the motion files in the RAM memory. Hence,
it is the available RAM memory that limits the duration of a simulated movement.
If a movement is described for example as a waypoint file, its duration is the product of
the used resolution and the number of waypoints. Thus, the maximum number of way-
points in a waypoint file depends on the used resolution.
For a given available RAM memory, the maximum time duration a waypoint file can
have is calculated as:
TimeDuration
●
The RAM
●
10 ms is the internal resolution
●
6*8 bytes are required to store one resampled waypoint;
Waypoints values are defined in double-precision floating point format (doubles)
and a resampled waypoint requires 6 doubles with 8 bytes each.
A warning message indicates the following situations:
●
The time duration of the loaded waypoint file exceeds the maximum allowed value
●
The RAM memory is insufficient to process the file
Example:
If a waypoint file contains 4 waypoints and uses a resolution of 50 ms, then:
●
#Waypoints*Resolution
4*50 = 200 ms long.
●
The file is resampled to the internal resolution of 10 ms (i.e. sampling rate of 100
Hz) and the resulting number of samples is:
#Samples = TimeDuration
●
Storing these 20 samples requires a memory of #Samples * 6*8 [bytes] = 20*48 =
960 bytes.
A.2 Vehicle Description Files (Used for Smoothening)
The vehicle description files use the file extension *.xvd. The following is a simple
example of the file format.
<vehicle>
<info name="Car"/>
<limits>
User Manual 1178.6379.02 ─ 01
Chapter A.1.6, "Calculating the Maximum Time Duration of a Movement
on page 399.
[ms] = (RAM
max
is the available RAM memory size, e.g. 1 Gbyte;
Size
WaypointFile

Vehicle Description Files (Used for Smoothening)

[bytes]/6*8[bytes])*10[ms], where:
Size
= TimeDuration
[ms] / Resolution
WaypointFile
User Environment Files
, i.e. the waypoint file is
WaypointFile
[ms] = 200 / 10 = 20
Internal
399