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positionactuator-relative

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positionactuator-relative

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Library

Iconic Diagrams\Mechanical\Translation\Actuators

Use

Domains: Continuous. Size: 1-D. Kind: Iconic Diagrams (Translation), Block Diagrams.

Description

This model represents an ideal actuator. A position input signal is differentiated by a state variable filter to a velocity difference between its two terminals:

 

p_high.v = p_low.v + dx/dt;

p_low.F = p_high.F = indifferent;

 

Differentiation is performed by a state variable filter:

DifferentiateSVF

The S-domain function of this filter is equal to:

DifferentiateSVFequation

where f is the cut-off frequency. For very high values of f, the output becomes the pure derivative of the input. High values of f, however, increase simulations times. A good trade-off is a starting value of 1e5.

Interface

Ports

Description

p_high, p_low

Both terminals of the Translation port p.

Causality

 

fixed velocity out

 

Input

 

x

Position [m].

Parameters

 

f

v_initial

Cut-off frequency of the differentiation [Hz].

Initial velocity output of the differentiation [m/s].