| With the increasing demands of maneuverability, radar stealth, reliability, flight safety and otheraspects, more and more aircrafts are being designed with many more than the classical three sets ofcontrol effectors (ailerons, elevator, and rudder). The next generation of highly maneuverableairplanes is projected to have more than20primary flight control effectors. The effective allocation ofthese controls to achieve specific flight objectives is the redundant control problem.Most commonly used method of the redundant control is that firstly designing control law to get3-axis torque of controlling aircrafts, then converting the torque to deflection commands of actuatorsby using multi-control allocation algorithms.This paper studies the redundant control technology, and applies it to the super low altitudeairdrop. The main work includes establishing the motion equations of the airplane-cargo system,designing flight control law of the airdrop system, studying the multi-control allocation algorithms,eliminating the impact of cargo sliding, and simulating the super low altitude airdrop system withmulti-control.There are two main innovations in this paper. First, it presents a new direct allocation algorithmnamed "parallel edges searching algorithm". By coordinate transformation and projection, thealgorithm transforms the n-objective constrained control allocation problem into some two-objectiveconstrained control allocation problems, and greatly reduces computational complexity as well asimproves the limitation of other direct allocation algorithms which can only allocate3-objictive.Second, according to the principle of direct lift control, a collision avoidance subsystem was designed.It effectively avoids the height control delay by elevators and the coupling of vertical movement andpitching movement, reduces the risk of aircraft collision，and provides protection for the super lowaltitude airdrop. |
