Dynamic Control Allocation Using Constrained Quadratic Programming

Control allocation deals with the problem of distributing a given control demand among an available set of actuators. Most existing methods are static in the sense that the resulting control distribution depends only on the current control demand. In this paper we propose a method for dynamic control allocation, in which the resulting control distribution also depends on the distribution in the previous sampling instant. The method extends the traditional generalized inverse method by also penalizing the individual actuator rates. Its main feature is that it allows for different control distributions during the transient phase of a maneuver and during trimmed flight. The control allocation problem is posed as a constrained quadratic programming problem which provides automatic redistribution of the control effort when one actuator saturates in position or in rate. When no saturations occur, the resulting control distribution coincides with the control demand fed through a linear filter which can be assigned different frequency characteristics for different actuators.