Reconfiguration of an Aircraft’s Executive Subsystem in Case of Failures Leading to a Decrease in the Control Matrix Rank

We consider ensuring the flight safety of an aircraft in case of failures in executive subsystem leading to a decrease in the control matrix rank. At such failures it is impossible to maintain the normal flight dynamics. We suggest an approach using a pseudoinverse matrix of control for rearranging the control signals between actuators remaining operable. This approach is algebraically analogical to reconfiguration with keeping the normal dynamics. However it is based on some parameterized reference dynamics which differs from the normal one. Appearing deviations between real dynamics in case of failures and the reference dynamics are minimized by the least squares technique. Parameters of the reference dynamics are chosen so as to achieve the shortest transients possible at meeting the demands of flight safety and control implementation (constraints of state and control vectors) for any combination of failures from a certain class. An example of controlling the civil aircraft longitudinal motion demonstrates the suggested approach application. Mathematical simulation has shown that when applying the reconfiguration laws based on reference dynamics, for the chosen range of initial conditions the state and control vectors constraints are observed despite some extension of transient. The reference dynamics is quite accurately implemented at any combination of considering failures. This gives a priori information on flight dynamics in case of examined failures regardless of specific failed devices.