【作者】 李智；

【导师】 陆宇平；

【作者基本信息】 南京航空航天大学 ， 导航、制导与控制， 2010， 硕士

【摘要】 运输机超低空空投技术能显著提高空军远程机动能力和后勤保障速度,对于军队应对多种安全威胁、完成多样化军事任务以及维护不断扩展的国家利益具有重要意义。由于运输机超低空空投属于C种飞机阶段,需要极高精度的航迹跟踪和姿态保持。空投过程中,运输机具有如下几个特点:一是速度低,气动特性大大降低,抗扰动能力较弱;二是货物对飞机的扰动剧烈,飞机重心发生变化;三是随着飞机高度下降,飞机遭遇紊流、低空风切变等大气扰动的概率会明显增加。本文通过研究与仿真,针对大气扰动对空投任务的影响,创新性地提出了扰动补偿控制方法。首先给出了研究飞行控制技术经常采用的三种大气扰动模型:随机紊流模型,离散突风模型和低空风切变模型。然后给出带大气扰动的超低空空投六自由度非线性数学模型,并在此基础上,深入分析了运输机与大气扰动运动的耦合。接着,采用经典控制理论分别设计了超低空空投下滑段、拉平段、空投拉起段的基本控制器和横侧向的基本控制器。在基本控制器基础上分别设计了大气扰动的纵向和横侧向补偿控制器。最后,引入模糊控制理论,设计了超低空空投大气扰动补偿的模糊控制器。通过仿真分析得出结论,大气扰动补偿的经典控制器和模糊控制器均能显著补偿大气扰动的影响。在受到一定强度大气扰动情况下,运输机的航迹和姿态均能够达到超低空空投性能的严格要求。两种控制器的比较可以看出,模糊控制器具有更好的鲁棒性,航迹跟踪效果也更精确。更多还原

【Abstract】 The TransportAircraft Ultra-Low Altitude Airdrop (ULAA) Technology can observably enhance the capability of long-range mobility and the speed of logistics support of Air Force. It still has realistic significances for the military to respond to various security threats, accomplish diverse military tasks and protect the expanding national interests. Because the transport aircraft flies in C phase while Ultra-Low Altitude Airdrop, high-accuracy flightpath tracking and attitude hold are required. During the course of Ultra-Low Altitude Airdrop, the transport aircraft has the following characteristics: First, the aerodynamic performance is not excellent any more and the capability of disturbance rejection declines. Second, the cargo’s impact is very violent and the center of gravity of the aircraft shifts. Third, the probability of encountering turbulence, wind shear increases observably.Via research and simulations, disturbance compensation control methods are presented innovatively to slow down the effect caused by atmospheric disturbance. First of all, stochastic turbulence model, discrete gust model and low-level wind shear model which are usually used in flight control research are presented. Then the nonlinear six-degrees-of-freedom model of transport aircraft ULAA with atmospheric disturbance is provided. Based on this model, coupling movement of aircraft and disturbance is deeply analysed. After this, ULAA glide, flare, airdrop-pull up basic controllers and lateral basic controllers are designed using classical control theory. Based on the basic controllers, the longitudinal and lateral atmospheric disturbance compensating conrollers are designed. At last, fuzzy control theory is introduced and the ULAA longitudinal and lateral atmospheric disturbance compensating fuzzy conrollers are designed.After analysing the results of simulations, conclusions are presented that both classical controllers and fuzzy controllers can compensate the effects of atmospheric disturbance. The flight path and attitude could meet the exact demands of ULAA while the transport aircraft is disturbed by different kinds of atmosphere. Compared with each other, fuzzy controllers have stronger robustness and higher flight path tracking accuracy.更多还原