ATVplus is a suite of MATLAB files that create a graphical user interface (GUI) to perform system identification and control system design using the ATV+ technique. The ATV+ identification method has been developed to allow the identification of linear transfer function models for SISO stable systems. The technique requires that three tests with a modified relay are performed on the process: from each of these tests the position of a point of the process Nyquist curve is obtained, and this information is later used to obtain a full model. The ATV+ identification technique has been presented and described in two papers [1, 2] published on Industrial Engineering Chemistry - Research, the full reference of which is given in the appendix.
The software has been developed in MATLAB and runs on version 5.3 and later. It is required that Simulink and the Control System Toolbox are also installed in the system. The software is divided in three packages that can be run separately and independently:
-) the relaytests package: a simulated process is used to perform the relay tests and obtain the data which will allow the identification of the model;
-) the atvplus package: the relay data are analysed and different order models are identified, asking the user to choose the most appropriate.
-) the controldesign package: several controllers can be designed on the basis of the identified model; closed loop simulations are performed and the performance of the controllers can be compared.