blockTruncatedNormalNoise

Noise generator with truncated normal distribution

Extends from Modelica.Blocks.Interfaces.PartialNoise (Partial noise generator).

Information

A summary of the common properties of the noise blocks is provided in the documentation of package Blocks.Noise. This TruncatedNormalNoise block generates reproducible, random noise at its output according to a truncated normal distribution. This means that normally distributed random values are truncated to the band y_min ... y_max. Measurement noise has often this distribution form. By default, the standard parameters of the truncated normal distribution are derived from y_min ... y_max:

mean value = (y_max + y_min)/2,
standard deviation = (y_max - y_min)/6 (= 99.7 % of the non-truncated normal distribution are within y_min ... y_max).

For an example see Examples.Noise.Distributions. By default, two or more instances produce different, uncorrelated noise at the same time instant. The block can only be used if on the same or a higher hierarchical level, model Blocks.Noise.GlobalSeed is dragged to provide global settings for all instances.

Parameters

TypeNameDefaultDescription
SI.PeriodsamplePeriod (from PartialNoise)Period for sampling the raw random numbers
IntegerlocalSeed (from PartialNoise)The actual localSeed
Realy_minLower limit of y
Realy_maxUpper limit of y
Advanced › Noise generation
BooleanenableNoise (from PartialNoise)globalSeed.enableNoise= true: y = noise, otherwise y = y_off
Realy_off (from PartialNoise)0.0Sets y = y_off if enableNoise=false (or time<startTime, see below)
Realmu(y_max + y_min)/2Expectation (mean) value of the normal distribution
Realsigma(y_max - y_min)/6Standard deviation of the normal distribution
Advanced › Initialization
BooleanuseGlobalSeed (from PartialNoise)true= true: use global seed, otherwise ignore it
BooleanuseAutomaticLocalSeed (from PartialNoise)true= true: use automatic local seed, otherwise use fixedLocalSeed
IntegerfixedLocalSeed (from PartialNoise)1Local seed (any Integer number)
SI.TimestartTime (from PartialNoise)0.0Start time for sampling the raw random numbers

Connectors

TypeNameDefaultDescription
RealOutputy (from SO)Connector of Real output signal

Revisions

Date Description
June 22, 2015
DLR logo Initial version implemented by A. Klöckner, F. v.d. Linden, D. Zimmer, M. Otter.
DLR Institute of System Dynamics and Control