ASPECT: industrial self-tuning nonlinear controller on a PLC

The presented self-tuning nonlinear controller ASPECT (advanced control algorithms for programmable logic controllers) is intended for control of a practically important class of nonlinear processes that may be presented by a set of low-order local linear models. The model is obtained by means of experimental modelling using an online learning procedure that combines model identification with pre- and post-identification steps that provide reliable operation. There is a choice of several control algorithms suitable for different processes that may be used for control and whose parameters are automatically tuned from the model. The controller monitors the resulting control performance and may react to detected irregularities. The choice of the controller structure and algorithms allows implementation on available industrial hardware, such as programmable logic controllers (PLCs) or open controllers, and simplifies configuration of parameters.