A unified strategy for windup prevention in control systems with multiple saturating actuators

[摘要] ENGLISH ABSTRACT:A unified method is proposed to treat saturation in both Multi-Input-Multi-Output MIMOand Single-Input-Single-Output controllers. This method offers superior performance overexisting MIM 0 anti-saturation schemes.The anti-saturation problem is posed as a linear programming problem. A practical andefficient implementation of the algorithm is developed by transforming the problem into itsdual linear programming form. The problem, in dual form, is then solved using the dualsimplex method rather than the primal simplex method. The nature of the problem whenexpressed in dual form and the properties of the dual simplex method are harmonised toguarantee an initial basic feasible solution and an optimal bounded final solution in a finite,predictable and minimal number of iterations.The resultant controller never saturates, hence cannot windup. Furthermore the resultantcontroller always applies the optimal control effort to the plant to minimise the error signalinput as follows:• The controller is governed such that while the future free response combined with thepresent forced response of the controller results in no saturation limits being exceeded,now or at some time in the future, the normal linear response of the controller prevails.• When the future free response combined with the present forced response of the controllerwill result in a saturation limit being reached, now or at some time in the future,the present time input signal into the controller is optimally governed to prevent thesaturation limit from being exceeded at any future time.

[发布机构] Stellenbosch University