Performance of an adaptive tuner for pressure rise control in an axial ducted fan

An adaptive tuner for maintaining the pressure rise within certain limits in an axial ducted fan has been described. Process dynamics is assumed to be a single input (throttle position) and single output (pressure differential) case and is assumed to be linear in the neighborhood of the throttle position (u(m)) corresponding to maximum outlet pressure at the given value of the impeller speed. The initial value of the process parameters are obtained by randomly actuating the throttle in the range +/-5% of u(m) and running on-line, the recursive least square (RLS) algorithm. The outlet pressure reaches its maximum value within these bounds for the range of the impeller speed considered. The process is found to have always, two stable poles and one stable/unstable zero. At each sampling instant, the process parameters are estimated by RLS algorithm, regulator parameters calculated and control signal generated. The adaptive tuner takes care of the variation of process parameters and maintains the outlet pressure to better regulation when compared to other control techniques.