True digital control: an integrated environment for the design of direct digital and adaptive control systems

Presents a digital control system design methodology that is based wholly in discrete time, as opposed to merely being the digitisation of a continuous time design. The reason for adopting this 'true digital control' (TDC) strategy is that it provides a logical, almost automatic, general approach to the design of digital controllers for SISO systems, and, in addition, experience to date suggests that it offers several advantages over its 'digitised continuous' counterparts. The underlying strength of the TDC approach, is the use of discrete time modelling techniques to select an appropriate controller sampling interval: a good choice of sampling time will improve the quality of the discrete time process model, which, in turn, will result in improved control system performance. The TDC strategy comprises five distinct stages: data collection, data pre-processing, model identification and parameter estimation, control system design, and, if required, self-adaptive control system design. An outline of the strategy is presented. Its use is subsequently illustrated by applying the method to the design of a flow control system.<>