Smith predictor for dead-time dominant processes

Due to changes in the security policy of Java it is necessary to white-list the following servers in the Security settings of Java to run the applet.

  • https://www.rexcontrols.cz
  • https://www.rexcontrols.com
  • http://www.pidlab.com

Smith predictor

The simulator shows the basic Smith predictor structure build from RexLib function blocks. The scheme is intended to control processes with dominant dead-time. The task contains one PIDMA controller and three MDL blocks. One MDL serves as a process model while the other two are the part of Smith predictor. P0 and PDT represent the process model without and with time delay, respectively. 


Firstly, the Smith's feedback has to be disconnected (SMITH=0). Then the PIDMA controller can be tuned. The params obtained are writen directly to the process model blocks P0 and PDT. Finally, the Smith's feedback can be closed (SMITH=1) and the controller retuned for the process without time delay.

How to start the simulator?

Before starting the simulator (applet) by START start.gif, 648B button, the sampling period can be set in the field Sampling time. The continous applet running can be stopped by STOP stop.gif, 666B button or paused by PAUSE pause.gif, 1,1kB button. The simulation speed can be adjusted by the slider. The re-init button reinit.png, 858B reset all parameters to initial state.

All parameters of active blocks (non-shadow) can be changed in the dialog which is invoked by cliking at the block. Detailed description of block parameters is available in Function blocks reference manual.