Sequential quadratic programming-based non-cooperative target distributed hybrid processing optimization method

The distributed hybrid processing optimization problem of non-cooperative targets is an important research direction for future networked air-defense and anti-missile firepower systems. In this paper, the air-defense anti-missile targets defense problem is abstracted as a nonconvex constrained combinatorial optimization problem with the optimization objective of maximizing the degree of contribution of the processing scheme to non-cooperative targets, and the constraints mainly consider geographical conditions and anti-missile equipment resources. The grid discretization concept is used to partition the defense area into network nodes, and the overall defense strategy scheme is described as a nonlinear programming problem to solve the minimum defense cost within the maximum defense capability of the defense system network. In the solution of the minimum defense cost problem, the processing scheme, equipment coverage capability, constraints and node cost requirements are characterized, then a nonlinear mathematical model of the non-cooperative target distributed hybrid processing optimization problem is established, and a local optimal solution based on the sequential quadratic programming algorithm is constructed, and the optimal firepower processing scheme is given by using the sequential quadratic programming method containing non-convex quadratic equations and inequality constraints. Finally, the effectiveness of the proposed method is verified by simulation examples.

Impedance control of multi-arm space robot for the capture of non-cooperative targets

Robotic systems are expected to play an increasingly important role in future space activities. The robotic on-orbital service, whose key is the capturing technology, becomes a research hot spot in recent years. This paper studies the dynamics modeling and impedance control of a multi-arm free-flying space robotic system capturing a non-cooperative target. Firstly, a control-oriented dynamics model is essential in control algorithm design and code realization. Unlike a numerical algorithm, an analytical approach is suggested. Using a general and a quasi-coordinate Lagrangian formulation, the kinematics and dynamics equations are derived.Then, an impedance control algorithm is developed which allows coordinated control of the multiple manipulators to capture a target.Through enforcing a reference impedance, end-effectors behave like a mass-damper-spring system fixed in inertial space in reaction to any contact force between the capture hands and the target. Meanwhile, the position and the attitude of the base are maintained stably by using gas jet thrusters to work against the manipulators' reaction. Finally, a simulation by using a space robot with two manipulators and a free-floating non-cooperative target is illustrated to verify the effectiveness of the proposed method.

Design of a Non-cooperative Target Capture Mechanism

A passive compliant non-cooperative target capture mechanism is designed to maintain the non-cooperative target on-orbit. When the relative position between capture mechanism and satellite is confirmed,a pair of four-bar linkages lock the docking ring,which is used for connecting the satellite and the rocket. The mathematical model of capture mechanism and capture space is built by the Denavit-Hartenberg(D-H)method,and the torque of each joint is analyzed by the Lagrange dynamic equation. Besides,the capture condition and the torque of every joint under different capture conditions are analyzed by simulation in MSC. Adams. The results indicate that the mechanism can capture the non-cooperative target satellite in a wide range. During the process of capture,the passive compliant mechanism at the bottom can increase capture space,thereby reducing the difficulty and enhance stability of the capture.

Design of a Flexible Capture Mechanism Inspired by Sea Anemone for Non-cooperative Targets

Robotic grippers have been used in industry as end-effectors but are usually limited to operations in pre-defined workspace.However,few devices can capture irregularly shaped dynamic targets in space,underwater and other unstructured environments.In this paper,a novel continuum arm group mechanism inspired by the morphology and motions of sea anemones is proposed.It is able to dissipate and absorb the kinetic energy of a fast moving target in omni-direction and utilize multiple arms to wrap and lock the target without accurate positioning control.Wire-driven actuation systems are implemented in the individual continuum arms,achieving both bending motion and stiffness regulation.Through finite element method,the influence of different configurations of the continuum arm group on the capture performance is analyzed.A robotic prototype is constructed and tested,showing the presented arm group mechanism has high adaptability to capture targets with different sizes,shapes,and incident angles.

Non-cooperative target pose estimation based on improved iterative closest point algorithm

For localisation of unknown non-cooperative targets in space,the existence of interference points causes inaccuracy of pose estimation while utilizing point cloud registration.To address this issue,this paper proposes a new iterative closest point(ICP)algorithm combined with distributed weights to intensify the dependability and robustness of the non-cooperative target localisation.As interference points in space have not yet been extensively studied,we classify them into two broad categories,far interference points and near interference points.For the former,the statistical outlier elimination algorithm is employed.For the latter,the Gaussian distributed weights,simultaneously valuing with the variation of the Euclidean distance from each point to the centroid,are commingled to the traditional ICP algorithm.In each iteration,the weight matrix W in connection with the overall localisation is obtained,and the singular value decomposition is adopted to accomplish high-precision estimation of the target pose.Finally,the experiments are implemented by shooting the satellite model and setting the position of interference points.The outcomes suggest that the proposed algorithm can effectively suppress interference points and enhance the accuracy of non-cooperative target pose estimation.When the interference point number reaches about 700,the average error of angle is superior to 0.88°.

A Method to Obtain the Moving Speed of Uncooperative Target Based on Only Two Measurements

The existing research results show that a fixed single station must conduct three consecutive frequency shift measurements and obtain the target’s moving speed by constructing two frequency difference equations. This article proposes a new method that requires only two consecutive measurements. While using the azimuth measurement to obtain the angular difference between two radial distances, it also conducts two consecutive Doppler frequency shift measurements at the same target azimuth. On the basis of this measurement, a frequency difference equation is first constructed and solved jointly with the Doppler frequency shift equation. By eliminating the velocity variable and using the measured angular difference to obtain the target’s lead angle, the target’s velocity can be solved by using the Doppler frequency shift equation again. The new method avoids the condition that the target must move equidistantly, which not only provides an achievable method for engineering applications but also lays a good foundation for further exploring the use of steady-state signals to achieve passive positioning.

An innovative inertial parameters identification method for non-cooperative space targets based on electrostatic interaction

Inertial characteristics of non-cooperative targets are crucial for space capture and sub-sequent on-orbit servicing.Previous methods for identifying inertial parameters involve proximity operations,which are associated with the risk of collision with non-cooperative targets.This paper introduces a long-range,contactless method for identifying the inertial parameters of a non-cooperative target during the pre-capture phase.Specifically,electrostatic interaction is used as an external excitation to alter the target's motion.A force estimation algorithm that uses measure-ments from visual and potential sensors is proposed to estimate the electrostatic interaction and eliminate the need for force sensors.Furthermore,a recursive estimation-identification framework is presented to concurrently estimate the coupled motion state,weak electrostatic interaction,and inertial parameters of the target.The simulation results show that the proposed method extends the identification distance to 170 times that of the previous method while maintaining high identifica-tion precision forall parameters.

Analytic optimal pose tracking control in close-range proximity operations with a non-cooperative target

This paper investigates an analytical optimal pose tracking control problem for chaser spacecraft during the close-range proximity operations with a non-cooperative space target subject to attitude tumbling and unknown orbital maneuvering.Firstly,the relative translational motion between the orbital target and the chaser spacecraft is described in the Line-of-Sight(LOS)coordinate frame along with attitude quaternion dynamics.Then,based on the coupled 6-Degree of Freedom(DOF)pose dynamic model,an analytical optimal control action consisting of constrained optimal control value,application time and its duration are proposed via exploring the iterative sequential action control algorithm.Meanwhile,the global closed-loop asymptotic stability of the proposed predictive control action is presented and discussed.Compared with traditional proximity control schemes,the highlighting advantages are that the application time and duration of the devised controller is applied discretely in light of the influence of the instantaneous pose configuration on the pose tracking performance with less energy consumptions rather than at each sample time.Finally,three groups of illustrative examples are organized to validate the effectiveness of the proposed analytical optimal pose tracking control scheme.

Fixed-wing UAV guidance law for ground target over-flight tracking

This paper studies the problem of tracking a ground target for a fixed-wing unmanned aerial vehicle(UAV) based on the proposed guidance law. The algorithm ensures that a UAV continuously overflies the target whether it is fixed or moving. The requirements of the UAV flight constraints such as bounded airspeed and acceleration are considered. A Lyapunov function is constructed to prove the stability of the proposed guidance law,and parameter design criteria have been developed. Considering the fixed and moving ground targets, numerical simulations are performed to verify the feasibility and benefits of the proposed guidance algorithm.

城市无人机航线飞行间隔与调控频率综合研究

聚焦城市无人机航线飞行,为确保运行安全,需要为无人机配备合适的飞行间隔。面向同航线纵向飞行场景,研究了考虑冲突频率与碰撞概率且符合ICAO间隔制定原则的间隔调控模型。通过研究仅考虑无人机定位误差下的碰撞风险,得到无人机纵向飞行间隔,作为后续间隔计算的基准;通过综合考虑定位误差和速度误差引发的位置不确定性,计算伴随无人机航线飞行进程的碰撞风险。加大纵向间隔会延迟突破安全目标水平的时机,但随着飞行进程的推进,碰撞风险终将突破安全目标水平。基于此,提出了无人机位置调控机制,对2架无人机位置进行定期调控,以消除速度所产生的累积误差。针对某1个指定的安全目标水平,得到了纵向间隔与位置调控频率的关系曲线,发现二者存在博弈关系,实施高频调控,需要采取更小的航线间隔;反之,则需要加大航线间隔。同时,为兼顾城市空间与位置调控能力的双重约束,提出了选取曲率最大值位置的所需飞行间隔与调控频率作为折中方案,发现安全目标水平要求越严格,所需调控频率和飞行间隔越大。实验得到在满足安全目标水平为5×10^(-9)次/飞行小时情况下,所需调控频率为87次/h,所需纵向飞行间隔为90 m;同时在实际运行环境中,应用上述评估模型与方法可以客观选择所需间隔和调控频率。本文研究可以兼顾城市物流无人机空中运行的安全,提高城市空域利用率和派送效率。

基于OpenMV的无人机目标跟踪系统

无人机在众多领域展现出巨大的应用潜力,其中作为关键技术之一,目标跟踪对于提升无人机自主作业能力至关重要。文章介绍一种无人机目标识别与跟踪系统。该系统基于OpenMV平台,利用阈值分割的图像处理算法,确保目标识别的高精度与鲁棒性。通过分析图像中特定色块的位置,计算相对于图像中心的偏移量,进而确定目标运动轨迹。所获取的偏移信息被实时传输至无人机控制系统,无人机通过PID控制器调节,自动调整飞行路径,对目标实施紧密跟踪。在实现过程中,通过优化算法参数和进行大量实验测试,确保系统的稳定、可靠运行。实验结果表明,该系统能准确识别目标色块,并实现对目标的稳定伴飞,为无人机在目标跟踪、智能监控等领域的应用提供有力支持。

基于改进YOLOv8的飞机起降飞行姿态风险检测

飞机在执行飞行任务时,其起飞和降落两个阶段是整个飞行过程中最关键和最具挑战性的时刻之一,其起降飞行姿态的变化程度关系到整个飞机的安全性。为了降低飞机在起降过程的风险性,提出了一种基于改进YOLOv8的飞机起降飞行姿态的风险检测方法。该检测方法综合利用了CBAM注意力机制、GSConv轻量化卷积模块和HIOU准则函数等深度学习和目标检测技术,实现了对飞机机翼、起落架等关键结构部位的准确检测,以便利用识别到的飞行姿态特征参数来对飞机当前的安全状态进行分析和评估。经实验验证表明,该改进方法对于飞机起降阶段中的飞行姿态风险状况能够进行精准识别和检测,具有较高的可靠性。

FlightGear在无人机实时飞行仿真中的应用

无人机实时飞行仿真是无人机研制中不可缺少的一个过程,但是对于小型无人机来讲,开发一个完整的实时飞行仿真系统往往花费巨大。详细论述基于xPC Target的实时仿真系统设计,在此基础上,利用FlightGear飞行模拟器实现了无人机的三维实时可视化显示。该仿真系统开发简单,构造灵活,成本低,能够使开发人员将更多的精力花费在飞行控制算法研究上。

基于改进离散狼群算法的火力分配

随着无人机和智能弹药协同的兴起,进行高效的火力分配成为研究重点。传统的数学模型过于单一,不满足空对地合理分配需求;目前常用的元启发算法迭代较慢且容易陷入局部最优解。为了解决火力分配问题,提出了一种新的数学模型和改进离散狼群算法。模型兼顾摧毁目标价值最大化、己方损耗最小化、弹药协同打击;引入莱维飞行策略、汉明距离和编码段替换改进狼群算法中的智能行为。通过对比仿真,验证了新算法的高效性和可行性。

针对低速目标的飞行器中段航迹快速规划

针对长航程飞行器打击低速舰船目标的问题,提出一种基于滚动序列凸优化算法的中段航迹快速规划算法。使用滚动规划框架将航迹更新问题转化为初始与终端位置更新后的单次航迹规划子问题,构造多约束凸优化问题并使用序列凸优化算法求解。提出滚动规划周期收缩策略,减少航迹更新次数。设计了一种改进参考航迹生成算法并使用了信赖域自适应收缩策略,在保证规划效果的同时有效提高计算速度。仿真结果表明,该算法规划效果优良,可满足在线规划的要求,且与一般的滚动序列凸优化航迹规划算法相比速度更快。

全二维气相色谱—飞行时间质谱非靶向筛查页岩气场地不同样品中的微量有机污染物及溯源分析

以全二维气相色谱—飞行时间质谱为技术手段,通过对某页岩气开采场地样品中微量有机污染物进行非靶向筛查,构建了基于实际样品分析的有机污染物清单。通过对不同样品中有机污染物特征分析,解析了部分有机污染物的来源。烷烃是钻井泥浆中被识别出的主要有机污染物类型。与钻井泥浆相比,脱油岩屑中烷烃占比显著降低而羰基、醇类化合物占比升高,说明热脱附技术对石油烃类具有良好的去除效果,但对极性更强的羰基和醇类化合物的去除效果可能欠佳。烷烃和羰基化合物是压裂液和返排液中的主要污染物。在压裂液和返排液中还可识别出大量被用作抗菌剂、增塑剂、表面活性剂和引发剂的有机污染物。

A grasp planning algorithm under uneven contact point distribution scenario for space non-cooperative target capture

The contact point configuration should be carefully chosen to ensure a stable capture,especially for the non-cooperative target capture mission using multi-armed spacecraft.In this work scenario,the contact points on the base and on the arms are distributed on the opposite side of the target.Otherwise,large forces will be needed.To cope with this problem,an uneven-oriented distribution union criterion is proposed.The union criterion contains a virtual symmetrical criterion and a geometry criterion.The virtual symmetrical contact point criterion is derived from the proof of the force closure principle using computational geometry to ensure a stable grasp,and the geometry criterion is calculated by the volume of the minimum polyhedron formed by the contact points to get a wide-range distribution.To further accelerate the optimization rate and enhance the global search ability,a line array modeling method and a continuous-discrete global search algorithm are proposed.The line array modeling method reduces the workload of calculating the descent direction and the gradient available,while the continuous-discrete global search algorithm reducing the optimization dimension.Then a highly efficient grasping is achieved and the corresponding contact point is calculated.Finally,an exhaustive verification is conducted to numerically analyze the disturbance resistance ability,and simulation results demonstrate the effectiveness of the proposed algorithms.

基于神经网络剩余时间估计的导弹-目标动态分配方法

针对防空导弹动态目标分配问题,设计了一种基于神经网络的剩余飞行时间预测方法,该方法在计算中不仅考虑了弹目相对距离和导弹运动状态,还考虑了敌方目标的运动状态对预测结果的影响,提升了预测精度;结合该方法建立了综合考虑距离优势、角度优势和剩余飞行时间优势的目标分配模型,采用拍卖算法对该模型进行求解,给出整体最优的目标分配方案。仿真结果表明:神经网络模型的测试集预测误差在1 s以内,低于经典算法,拍卖算法的重分配计算用时能够满足系统的实时性要求。

防空装备虚拟射击试验仿真航迹生成方法

地面防空装备虚拟射击试验是一种“虚飞实打”的靶场试验新模式,能够有效降低试验成本、缩短试验周期,同时为检验装备边界性能提供了新手段,虚拟靶机仿真航迹生成是其中的难题。提出并实现一种目标运动方程叠加雷达测量误差模型的仿真航迹生成方法,综合运用多元线性回归分析和最小二乘法构建雷达测量误差模型,解决基于历史试验数据计算相应状态下雷达测量误差的难题。最后,选取历史试验数据进行验证分析,建立相应的雷达测量误差模型,通过叠加单机复杂战术机动行为,得到仿真航迹数据。分析表明,按照该方法生成的航迹高低角、方位角测量值的均方根误差分别为0.110 mil、0.166 mil,距离测量值均方根误差为2.285 m,能够满足试验需求。

基于xPC Target的无人机飞行控制系统实时仿真

无人机飞行控制系统的实时仿真是无人机研制中不可缺少的一个过程。本文详细论述了基于xPC Target的实时仿真系统设计。首先介绍了xPC Target的工作原理，其后设计了无人机飞行控制实时仿真系统，最后给出了基于该系统的仿真实例。