Hi Miquel,
National Instruments has a bundle for LabVIEW in order to improve control system development.
This bundle is called Control Design and Simulation. Within the bundle you can find a tool called System Identification Toolkit, where it allows you to combine data acquisition tools with system identification algorithms for accurate plant modeling.
More info
http://sine.ni.com/nips/cds/view/p/lang/en/nid/13855
http://zone.ni.com/devzone/conceptd.nsf/webmain/ef51d50670d7901086256f860076594e
If this tool is good for you, you´d be able to call to your sales representative of NI for more information.
Regards
Diego M.