Multi-agent Based Hierarchy Simulation Models of Carrier-based Aircraft Catapult Launch

With the aid of multi-agent based modeling approach to complex systems, the hierarchy simulation models of carrier-based aircraft catapult launch are developed. Ocean, carrier, aircraft, and atmosphere are treated as aggregation agents, the detailed components like catapult, landing gears, and disturbances are considered as meta-agents, which belong to their aggregation agent. Thus, the model with two layers is formed i.e. the aggregation agent layer and the meta-agent layer. The information communication among all agents is described. The meta-agents within one aggregation agent communicate with each other directly by information sharing, but the meta-agents, which belong to different aggregation agents exchange their information through the aggregation layer first, and then perceive it from the sharing environment, that is the aggregation agent. Thus, not only the hierarchy model is built, but also the environment perceived by each agent is specified. Meanwhile, the problem of balancing the independency of agent and the resource consumption brought by real-time communication within multi-agent system （MAS） is resolved. Each agent involved in carrier-based aircraft catapult launch is depicted, with considering the interaction within disturbed atmospheric environment and multiple motion bodies including carrier, aircraft, and landing gears. The models of reactive agents among them are derived based on tensors, and the perceived messages and inner frameworks of each agent are characterized. Finally, some results of a simulation instance are given. The simulation and modeling of dynamic system based on multi-agent system is of benefit to express physical concepts and logical hierarchy clearly and precisely. The system model can easily draw in kinds of other agents to achieve a precise simulation of more complex system. This modeling technique makes the complex integral dynamic equations of multibodies decompose into parallel operations of single agent, and it is convenient to expand, maintain, and reuse the program codes.

Modeling of Carrier-based Aircraft Ski Jump Take-off Based on Tensor

A general mathematical model of carrier-based aircraft ski jump take-off is derived based on tensor. The carrier, the aircraft body and the movable parts of the landing gears are treated as independent entities. These entities are assembled into a multi-rigid-body system with flexible links. Dynamical equations of each entity are derived on the basis of the Newton law and the Euler transformation. Using the invariance property of the tensor, the dynamical and kinematical equations are converted to tensor forms which are invariant under time-dependent coordinate transformations. Then the tensor-formed equations are expressed by the matrix operation. Differential equation group of the matrix form is formulated for the programming. The closure of the model is discussed, and the simulation results are given.

Parameter Optimization of Nose Landing Gear Considering Both Take-off and Landing Performance of Catapult Take-off Carrier-Based Aircraft

Optimization of the parameters of landing gear systems with double-stage air springs of catapult take-off carrier-based aircraft is here studied based on the mathematical equations of the classic dual mass spring-damper dynamic model.Certain standards for both take-off and landing performance are put forward.The contradictory factors between take-off and landing processes are analyzed.The optimization of oil in the pin area and the area near the rear oil hole is performed.Then these optimized parameters are used to assess the influence of the initial pressure of the low chamber,the ratio of the high chamber to the low chamber,and the tire inflation pressure on the performance of arresting landing and catapult take-off.The influences of these parameters on carrier-based aircraft and the aircraft-carrier on aircraft catapult take-off is also assessed.Based on the results of the simulation,respective take-off criteria must be drafted considering different types of aircraft and different take-off load cases,all of which must be matched to parameters relevant to catapult take-off.

Guidance and Control Techniques of Carrier-Based Aircraft for Automatic Carrier Landing

We summarize the guidance and control techniques of automatic carrier landing for carrier-based aircraft.First,we analyze the carrier landing operations of the manned fixed-wing aircraft,unmanned fixed-wing aircraft and helicopters.Second,we look into the navigation and guidance system and the flight control methods for current different aircraft.Finally,we draw several conclusions of the development prospects for aircraft carrier landing,including the precision landing control techniques,precision approach and landing guidance techniques,and adaptive,reconfigurable and intelligent flight control techniques.

Dynamics Analysis of Carrier-Based Aircraft with Off-Center Catapult Launch

In order to enhance the safety of the catapult launch of the carrier-based aircraft,the catapult launch multibody dynamic model is established aiming at the problem of off center catapult launch.The whole catapult process including four stages which are buffering,tensioning,releasing and taxiing is taken into consideration and the body dynamics of the off-center catapult during each stage is analyzed.The catapult launch dynamic differences between the conditions only considering taxiing and that considering four stages are compared,and the effects of the different initial off center distances considering four stages on the attitude,landing gear load and acceleration of the carrier based aircraft during catapult launch are discussed.The results show that only considering taxiing may underestimate the dynamics of the carrier-based aircraft substantially.When taking four stages into consideration,the initial off-center distance has small influence on the aircraft dynamic characteristics during buffering and tensioning but has larger influence on that during releasing and taxiing.The increase of the off-center distance will cause the enhancement of the aircraft rolling and yawing,which may lead to the load difference between the left and right landing gears and the increase of the aircraft lateral acceleration.The establishment and simulation of the catapult launch multi body dynamic model founded on buffering,tensioning,releasing and taxiing provide reference for the carrier-based aircraft design and analysis of the catapult launch dynamics.

DYNAMIC RESPONSE ANALYSIS OF CARRIER-BASED AIRCRAFT DURING LANDING

In view of the complexity of landing on the deck of aircraft carrier,a systematic model,composed of sixdegree-of-freedom mathematic model of carrier-based aircraft,four-degree-of-freedom model of landing gears and six-degree-of-freedom mathematic model of carrier,is established in the Matlab-Simulink environment,with damping function of landing gears and dynamic characteristics of tires being considered.The model,where the carrier movement is introduced,is applicable for any abnormal landing condition.Moreover,the equations of motion and relevant parameter are also derived.The dynamic response of aircraft is calculated via the variable step-size RungeKuta algorithm.The effect of attitude angles of aircraft and carrier movement during the process of landing is illustrated in details.The analytical results can provide some reference for carrier-based aircraft design and maintenance.

Optimal Preview Control for Automatic Carrier Landing System of Carrier-Based Aircraft with Air Wake

Carrier-based aircraft carrier landing is a special kind of tracking control problem and not suitable for classical control methods,which may miss the desired performance or result in overdesign.Therefore,we present an optimal preview control for automatic carrier landing system(ACLS)by using state information of system,as well as future reference information,which can avoid the shortcomings of classical control methods.Since the flight performance of carrier-based aircraft is disturbed by air wake when the aircraft flies near the area of carrier stern,we design a disturbance rejection strategy to ensure that aircraft track the glide path with high precision and robustness.Further,carrier-based aircraft is a complex nonlinear system.However,the nonlinear model of carrier-based aircraft can be linearized at equilibrium landing state and decoupled into the longitudinal model and the lateral model.Therefore,an optimal preview control system is designed.The simulation results of a carrier-based aircraft show that the optimal preview control system can effectively suppress air wake.Tracking accuracy of optimal preview controller is higher than that of the proportional integral differential(PID)control system.

Dynamic Evaluation Strategies for Multiple Aircrafts Formation Using Collision and Matching Probabilities

Configuration evaluation is a key technology to be considered in the design of multiple aircrafts formation(MAF)configurations with high dynamic properties in engineering applications.This paper deduces the relationship between relative velocity,dynamic safety distance and dynamic adjacent distance of formation members,then divides the formation states into collision-state and matching-state.Meanwhile,probability models are constructed based on the binary normal distribution of relative distance and relative velocity.Moreover,configuration evaluation strategies are studied by quantitatively analyzing the denseness and the basic capabilities according to the MAF collision-state probability and the MAF matching-state probability,respectively.The scale of MAF is grouped into 5 levels,and previous lattice-type structures are extended into four degrees by taking the relative velocities into account to instruct the configuration design under complex task conditions.Finally,hardware-in-loop(HIL)simulation and outfield flight test results are presented to verify the feasibility of these evaluation strategies.

An Optimization Method of Formation Flight for Minimizing Fuel Consumption

A method for formation flight trajectory optimization was established.This method aims at minimizing fuel consumption of a two-aircraft formation flight,without changing the original trajectory of the leader.Candidate flight pairs were selected from all international flights arriving at or departing from China in one day according to the requirement of the proposed method.Aircraft performance database Base of Aircraft Data(BADA)was employed in the trajectory computation.By assuming different fuel-saving percentages for the following aircraft,pre-flight plan trajectories of formation flight were optimized.The fuel consumption optimization effect under the influence of different trajectory optimization parameters was also analyzed.The results showed that the higher the fuel savings percentage,the longer the flight distance of formation flight,but the smaller the number of formation combinations that can be realized,which is limited by the aircraft performance.The following aircraft flying along the approximate actual flight trajectory can be benefited as well,and the optimal fuel-saving efficiency is related to the expected fuelsaving efficiency of formation flight.

A bi-population immune algorithm for weapon transportation support scheduling problem with pickup and delivery on aircraft carrier deck

The weapon transportation support scheduling problem on aircraft carrier deck is the key to restricting the sortie rate and combat capability of carrier-based aircraft.This paper studies the problem and presents a novel solution architecture.Taking the interference of the carrier-based aircraft deck layout on the weapon transportation route and precedence constraint into consideration,a mixed integer formulation is established to minimize the total objective,which is constituted of makespan,load variance and accumulative transfer time of support unit.Solution approach is developed for the model.Firstly,based on modeling the carrier aircraft parked on deck as convex obstacles,the path library of weapon transportation is constructed through visibility graph and Warshall-Floyd methods.We then propose a bi-population immune algorithm in which a population-based forward/backward scheduling technique,local search schemes and a chaotic catastrophe operator are embedded.Besides,the randomkey solution representation and serial scheduling generation scheme are adopted to conveniently obtain a better solution.The Taguchi method is additionally employed to determine key parameters of the algorithm.Finally,on a set of generated realistic instances,we demonstrate that the proposed algorithm outperforms all compared algorithms designed for similar optimization problems and can significantly improve the efficiency,and that the established model and the bi-population immune algorithm can effectively respond to the weapon support requirements of carrier-based aircraft under different sortie missions.

多飞行器协同导航最优编队构型设计

高精度的协同导航是实现多飞行器编队飞行的关键,而编队构型是影响协同导航定位精度的重要因素。为了实现高精度的协同导航,建立了多飞行器协同导航系统模型,分析了编队构型及其动态变化对协同导航定位精度的影响,确定了使系统完全可观测的编队构型;进而,基于系统可观测度分析方法建立了协同导航定位精度评价模型,得到了多飞行器协同导航最优编队构型。仿真结果表明,相较于采用非最优编队构型,采用最优编队构型时的定位精度可提高75%以上,有效提升了编队飞行器的协同导航定位精度。

美航母编队数据链能力体系及发展趋势

航母编队数据链装备是连接航母编队中各作战平台的重要手段,通过数据链装备能够使各作战单元共享战场态势并协同完成作战任务。结合美军航母编队的发展演进和能力现状,首先,深入分析美航母编队数据链能力体系;接着,重点探讨了航母编队数据链的应用现状,主要包括航母编队作战概念发展演进、数据链应用模式、数据链消息标准;最后,给出了航母编队数据链未来发展趋势。相关研究内容能够为航母编队数据链装备建设及不同种类数据链融合发展并成体系运用提供参考。

有翼飞行器初制导阶段两段式协同集结方法

针对多枚有翼飞行器初制导阶段跨大空域飞行的协同集结问题,将协同集结问题转化为初始部署点到编队协同飞行区域之间的时间与位置协同问题。将协同集结过程划分为两个阶段,第一阶段飞行器间无信息交互,设计了带有集结角度约束的第一阶段时间协同集结方法,为各枚飞行器指定共同的集结时间和集结角度,采用模糊逻辑实现航迹控制与速度控制的合理分配,在可靠建立通信拓扑且满足终端放宽判断条件后,转入第二阶段协同集结飞行。第二阶段飞行器利用相互间构建的通信拓扑交互信息,为跟随者飞行器设计了基于编队跟踪控制的协同集结方法,通过李雅普诺夫理论对闭环系统稳定性进行了证明。仿真算例验证了所提方法的有效性。

基于几何拓扑约束的多飞行器高精度协同相对导航方法

多飞行器编队的多重作业能力强、可靠性高、整体效率高,是未来航空领域发展的重要方向,而高精度的相对导航是实现多飞行器编队飞行的关键。为了实现高精度相对导航,现有方法通常采用增加导航传感器种类或提高导航传感器测量精度的方式提升相对导航精度,但这不仅导致相对导航系统成本和体积的增加,而且会导致系统复杂性的增加。为此,本文从编队整体的几何拓扑结构出发,建立编队几何拓扑约束模型,并将其引入对相对惯导误差的估计中,提出一种基于几何拓扑约束的协同相对导航方法。所提方法通过引入整个编队的几何拓扑信息,能够在不增加导航传感器配置的前提下提升相对导航精度。在此基础上,设计得到一种多飞行器高精度协同相对导航方案。仿真结果表明,所提方法具有比现有方法更高的相对导航精度,其相对定姿、相对定位和相对测速的误差均方差分别减少了66.48%、48.73%和69.53%以上,可以实现多飞行器之间高精度的相对导航。

An approach for formation design and flight performance prediction based on aerodynamic formation unit:Energy-saving considerations

The performance improvement of swarm drones through aerodynamic shape optimization may be challenging due to folded size constraints imposed by the specific launch approach.However,fixed-wing aircraft swarms can benefit from formation flight in terms of energy consumption.This study introduces the concept of the"aerodynamic formation unit",which consists of two or three aircraft that form an inseparable unit of the formation.Considering the Unmanned Aerial Vehicle(UAV)distribution and wingtip vortex interference in the formation,two typical aerodynamic formation units are optimized by the variable-fidelity aerodynamic optimization method based on space mapping.The aerodynamic characteristics of the formation UAVs that affect flight performance,such as lift-to-drag ratio(L/D ratio)and static stability are analyzed by Computational Fluid Dynamics(CFD)simulations.The L/D ratio(cruising condition)of the following aircraft can be increased by 22.8%and 57.5%in the optimal units that involve two and three aircraft respectively.Moreover,this study conducts several CFD simulations for multi-aircraft formations formed by the units,which show that the average L/D ratio of the formation can be improved by more than 19%.These results verify the feasibility and effectiveness of the"aerodynamic formation unit"concept and the optimization framework for formation parameters.

基于实时可达域的高速飞行器分组队形优化

无动力高速飞行器作为欠驱动系统,在进行编队飞行队形优化时需系统地考虑其控制特点。借助“实时可达域”这一概念,在分析高速飞行器实际可到达区域的基础上,考虑集群成员数量变化以及实际集群包含多个任务小组的情况,提出一种适用于高速飞行器集群的分组动态队形优化方法。仿真结果表明提出的队形优化方法可对队形形状和参数进行一体化优化,可灵活适应多种飞行任务,同时也适用于集群成员数量发生变化的队形重构问题,具有重要应用价值。

一种无人机编队参考点飞行运动预判方法

为了实现无人机编队领机/虚拟参考点飞行运动的准确预判,提出了一种基于RBF神经网络的领机/虚拟参考点加速度估计方法。设计神经网络实际权值的更新方式,并运用改进的智能水滴算法获取神经网络高斯径向基函数中心(c_(1max),c_(2max))。其中,上述算法中水滴的速度和加速度模拟无人机的速度和加速度;根据水滴位置偏差、速度偏差组成的矩阵的范数以及网格土壤含量,更新水滴所处网格位置;在满足计算停止条件时,土壤含量最少网格处的(c_(1max),c_(2max))作为基函数中心输出。仿真表明,无人机编队能够快速响应机动飞行,队形变换结束后各机位置偏差和速度偏差足够小。可见,对领机/虚拟参考点加速度估计足够准确,估计方法有效。

气象海洋环境对航母编队反潜作战影响仿真模型设计研究

航母编队反潜作战受气象海洋环境影响显著。为了加强研究气象海洋环境对航母编队反潜作战的影响,论文运用作战仿真技术,构建航母编队反潜作战的气象海洋环境影响仿真模型体系,同时提出基于规则、原理、经验及综合仿真的建模方法,为开展不同气象海洋环境下航母编队反潜作战兵力运用问题研究提供技术支撑。该模型设计方法对于加强气象海洋环境影响仿真建设具有很强的指导和实践意义。

面向双机编队战术识别的时空图卷积网络

空战中的双机编队战术识别具有重要的研究意义和应用价值。为了提高双机编队战术识别的准确率和鲁棒性,采用深度学习技术,提出了一种面向双机编队战术识别的时空图卷积网络。首先,对双机编队协同作战序列数据进行了时空图构建;然后,通过空域图卷积网络模块、时域图卷积网络模块和通道注意力模块提取了双机编队战术的时空域特征;最后,利用分类器对双机编队战术进行了识别。试验结果表明,该网络可有效识别双机编队战术。

非完备信息下的超视距空战双机协同战术识别

针对超视距(BVR)空战过程中,受探测装置性能限制和敌方干扰等原因,导致目标信息易缺失,从而难以实时准确地识别敌方协同空战战术的问题,提出了一种基于动态贝叶斯网络(DBN)与参数学习的超视距空战双机协同战术识别方法。分析了超视距空战条件下的双机协同战术特征,根据长机和僚机的职能分工、当前态势及机动动作,构建了识别网络模型;为提高模型对双机协同战术的识别概率,采用期望最大参数学习方法优化网络参数;基于自回归模型对缺失目标信息进行修补,提出非完备信息下的双机协同战术识别推理算法。通过开展空战对抗仿真实验,验证了双机协同战术识别方法对于非完备信息下的超视距空战双机协同战术具有较高的识别概率和较好的实时性。