DEADBAND

Block Screenshot

Contents

• Description
• Parameters
• Default properties
• Interfacing function
• Computational function
• Example

Description

The Dead Band block provides a region of zero output.

It's a range of inputs for which the output remains unchanged. Outside that range there is a linear relationship between the deadband input u(k) and the dead band output v(k).

Below is shown a graph of a particular deadband:

It is defined by:

where

c_E > c_S

When the input u(k) is between C_s and C_E, the output v(k) is zero. When the input is greater than or equal to the upper limit C_E, the output is the input minus the upper limit. When the input is less than or equal to the lower limit C_s, the output is the input minus the lower limit.

Parameters

• End of dead band

  The upper limit of the dead band.

  Properties : Type 'vec' of size 1

• Start of dead band

  The lower limit of the dead band.

  Properties : Type 'vec' of size 1

• Zero crossing

  Select to enable zero crossing detection to detect when the limits are reached.

  Properties : Type 'vec' of size 1

Default properties

• always active: no

• direct-feedthrough: yes

• zero-crossing: yes

• mode: yes

• regular inputs:

  - port 1 : size [1,1] / type 1

• regular outputs:

  - port 1 : size [1,1] / type 1

• number/sizes of activation inputs: 0

• number/sizes of activation outputs: 0

• continuous-time state: no

• discrete-time state: no

• object discrete-time state: no

• name of computational function: deadband

Interfacing function

• SCI/modules/scicos_blocks/macros/Misc/DEADBAND.sci

Computational function

• SCI/modules/scicos_blocks/src/c/deadband.c (Type 4)

Example

The following is an example of a system with deadband.

The input is a sine wave. The magnitude is set to 2, the frequency to 1.25 and the phase to 0. The Deadband block has the following parameters:

This plot shows the effect of the dead band on the sine wave.