The application of function reconfiguration for digital fly-by-wire flight control system

This paper describes a method of function reconfiguration, dealing with the failure of helm control. When a helm of the aircraft fails, how to reconfigure the remaining normal helms to balance the aircraft again is an important problem. This paper introduces a method to solve this problem, and simulates the airplane with a computer. In the Fly-By-Wire flight control system, we can instigate a contol mixer which reassigns the control to helms, with regard to the control law and the actuator. Normally, it is an identification matrix; when a failure occurs, an algorithm is used to calculate the matrix, so that the control law has the same effect as the state before failure. There are two algorithms for two fail modes of the helm: turn to middle and lock. As an illustration example, the function reconfiguration method is exercised on an airplane, it is shown that with the helm turning to middle failure mode, the effect of using the reconfiguration algorithm is satisfactory. In addition it is also shown via simulation that with the lock failure mode, the use of this reconfiguration method is feasible when the failed helm locks within the limited angle