Research On Flight Control For High-altitude Long-endurance Unmanned Aerial Vehicle

The development and wide application of Unmanned Aerial Vehicle(UAV) beganafter World War II., UAV have been widely used in military and civilian aspect afterdecades of development. In terms of military,it was successfully applied to targetdetection, localization, strike,etc. In civilian area, it was used in daily patrols,geological exploration, disaster monitoring, environmental control, etc. Represented bythe U.S."Global Hawk", the rapid development of high-altitude long-endurance UAVbegan in the1990s. Its strong endurance, mount ability, hang time make it manyincomparable advantages to other UAVs, even superior than most of manned aircrafts.Because of its great influence to a war, it is considered to be a country’s strategic asset.Our country has vast expanse of territory and territorial sea, facing complicatedboundary and territorial disputes,so there is an urgent demand for high-altitudelong-endurance UAV. At present,our country is still in the development stage on theresearch of high-altitude long-endurance UAV, carrying out study of flight control lawhas important practical significance. This paper designed a flight control law for it andcarried out a series of simulations to prove its validation.(1)Established the6degrees of freedom（DOF）,12order nonlinear differentialequation for the high-altitude long-endurance UAV.(2)An attitude control law was designed,based on Active Disturbance RejectControl (ADRC) method and nonlinear dynamic inversion technique, simulationshowed that the control law was designed reasonable and the result was satisfactory.(3)The design of tracking control law was divided into two channels——verticalcontrol and lateral control, both were based on ADRC method and nonlinear dynamicinversion technique,the result of simulation showed that the control law can tracking thereference input signal effectively and keep a fixed altitude at the same time.(4) Simulations for internal and external disturbance were carried out, as well asfor long time endurance and high altitude characteristics. The results showed that thecontrol law can effectively resist the system disturbance and can adapte to the quality orheight viariations,thus the control law has good robustness.