基于剪式陀螺系统的空间飞行器非线性姿态控制

为避免控制力矩陀螺系统奇异,采用三对剪式陀螺垂直安装构形构成一个控制力矩陀螺系统作为空间飞行器姿态控制的执行机构。基于Newton-Euler法推导出剪式陀螺系统操纵空间飞行器姿态运动的精确数学模型,并在此基础上设计空间飞行器大角度姿态机动的非线性控制律,在设计的同时证明系统的稳定性。对剪式陀螺系统进行奇异性分析,分析表明该系统无内部奇异。提出一种剪式陀螺系统在陀螺同步条件下的伪逆操纵律。为提高同步性能和抗扰动能力,基于Lyapunov稳定性理论设计剪式陀螺系统的自适应非线性反馈控制器。仿真验证所设计的控制律和操纵律的有效性以及该陀螺系统驱动空间飞行器进行大角度姿态机动的能力。     

采用激光辅助装置的机器人视觉跟踪自适应控制

本文从机器人视觉系统的实际问题出发,提出一种采用激光辅助装置的机器人视觉系统对运动目标进行跟踪的自适应控制方案,介绍了自适应系统的结构并对自适应律的设计进行了推导。     

一种新型智能导引律及其三维可视化仿真

针对空空导弹的导引问题,基于模糊逻辑,提出一种新型智能导引律.将导弹与目标的接近速度以及导弹的视线角速度作为模糊控制器的输入,指令加速度作为输出,并在传统的模糊逻辑控制基础上引入了一个非线性变论域函数,从而实现动态改变模糊变量论域的目的.在此基础上,采用Visual C ＋＋和OpenGL来设计空战的三维可视化仿真平台,并实现了逼真的动画效果.     

基于Backstepping的改进等速趋近律AGV滑模轨迹跟踪控制方法

针对自动导引小车(AGV)轨迹跟踪过程中如何快速平稳消除行进所产生的距离和角度误差问题,提出了一种改进等速趋近律的滑模轨迹跟踪控制方法。在全局坐标系下建立了AGV运动学模型,基于反演算法(Backstepping)处理非线性系统的控制策略得到AGV的滑模切换函数,从而解决了非线性系统滑模控制切换函数难的问题;为了更好地实现AGV从任意初始的偏差状态达到滑模切换面,针对等速趋近律中ε常数对趋近过程的影响,通过连续的函数取代原趋近律中的符号函数,得到基于改进等速趋近律AGV滑模控制的切换函数式和轨迹跟踪的控制律式。通过仿真数据与实验结果表明,所提出的轨迹跟踪控制方法能够使AGV在不同转弯半径和不同速度下均能实现较快的误差纠偏,并最终使系统趋于稳定。     

国外反鱼雷水声对抗技术与发展趋势

鱼雷是针对水面与水下目标而出现的一种进攻性武器,尤其是对于水下目标来说,鱼雷的威胁是致命的,因此,世界各国在反鱼雷水声对抗技术方面进行了长期研究,同时,出现了大量的反鱼雷水声对抗器材。本文以国外反鱼雷水声对抗技术为研究内容,通过实例分析的方式对国外反鱼雷水声对抗器材进行介绍的同时,分析国外反鱼雷水声对抗技术发展趋势,从而为我国鱼雷和反鱼雷水声对抗技术发展提供参考。     

航空反潜鱼雷发现概率分析与仿真计算

根据目前主流航空反潜鱼雷搜索攻击图形,对被攻击潜艇规避分布作椭圆合理简化后,基于航空反潜鱼雷投弹综合散布误差分析,利用圆目标面积覆盖潜艇法对鱼雷发现概率进行分析和仿真计算。为提高航空反潜鱼雷的战术使用过程中的攻击效果,在鱼雷空投散布和目标指示精度中提供了决策支持。     

一维波导行波主动控制律研究

本文根据行波理论模型,推导了具有压电陶瓷作动器的一维柔性波导在单点测量,单点激动方案下的主动控制律和相应的补偿器公式.     

RBF神经网络补偿的并联机器人控制研究

为了实现对三自由度Delta并联机器人更精确的轨迹跟踪控制,对并联机构的动力学建模不确定性进行研究,提出了计算力矩控制基础上的RBF神经网络在线补偿控制策略。利用Lyapunov理论推导了神经网络在线权值自适应律,保证了系统稳定性。运用RBF神经网络在线自学习系统的不确定性,提高了控制效率同时增加算法的自适应性。在Simmechanics中建立系统物理模型并在Simulink中设计控制器,之后进行Simulimk/Simmechanics联合仿真,结果表明算法优于计算力矩控制,可以有效减小跟踪误差的收敛半径,实现对目标轨迹的准确跟踪。     

逆系统方法在自动导引制导系统中的应用

基于低阶等效辨识模型,将逆系统方法与参数辨识相结合,首次成功地应用于自动导引反坦克导弹这一多变量、时变、非线性制导系统设计中.利用快速鲁棒自适应控制方法实现了自动导引中的准平行接近制导律,且具视线角速度趋于零和最少测量条件,因此可实现直接碰撞目标,并使制导装置的机构简化、尺寸和重量减小.经过大量数学和半物理仿真试验表明,上述成果可用于实际工程当中.     

液压型风力发电机组低电压穿越分层控制研究

为提高液压型风力发电机组的电网适应性和低电压穿越能力,针对机组低电压穿越过程中的能量调控问题,提出一种基于分层控制思想的低电压穿越控制方法,即设计出基于风力机调桨控制的顶层控制、基于变量马达摆角控制的中层控制和基于节流阀开度控制的底层控制。为实现机组在控制过程中多变量的协调控制,以风力机弃风最小、惯性储能最大和节流阀能耗最小为优化目标,采用二次规划算法对多目标控制律进行规划,得到了最优控制律。通过AMESim和MATLAB/Simulink软件对多目标控制策略进行仿真分析,利用液压型风力发电机组半物理试验平台对控制律进行了验证。结果表明,所提出的控制方法可以有效降低机组在低电压穿越过程中的剩余能量,降低对发电机的冲击,提高机组的适应性。     

Game optimal receding horizon guidance laws and its equivalence to receding horizon guidance laws

In this paper, a game optimal receding horizon guidance law (GRHG) is proposed, which does not use information of the time-to-go and target maneuvers. It is shown that by adjusting design parameters appropriately, the proposed GRHG is identical to the existing receding horizon guidance law (RHG), which can intercept the target by keeping the relative vertical separation less than the given value, within which the warhead of the missile is detonated, after the appropriately selected time in the presence of arbitrary target maneuvers and initial relative vertical separation rates between the target and missile. Through a simulation study, the performance of the GRHG is illustrated and compared with that of the existing optimal guidance law (OGL).     

A novel fractional order PID navigation guidance law by finite time stability approach

In this paper, a novel fractional order proportional–integral–differential navigation guidance law utilizing finite time stability approach is presented in order to achieve robust performance for intercepting incoming targets. The proposed guidance law is designed following three-loop guidance and control scheme, considering the interceptor’s nonlinear 6 degrees-of-freedom model. In the outer loop, normal acceleration commands are generated by the proposed guidance law. In the intermediate loop, these commands are converted into equivalent body rate commands, which are tracked by dynamic inversion based autopilot in the inner loop. A fractional order circle criterion is developed for the finite time stability analysis of this proposed guidance law, whose stability conditions give an analytical bound for the flight up time in which stability can be insured. Extensive 6 degrees-of-freedom simulations and a variety of comparison studies against maneuvering targets are implemented to demonstrate the effectiveness of the proposed guidance law. The simulation results show that the proposed guidance law has better performance when comparing with the proportional navigation and proportional–integral–differential navigation guidance laws.     

过失速大迎角条件下推力矢量飞机机动仿真

推力矢量飞机是我国下一代飞机发展的必然趋势。在过失速大迎角飞行条件下,常规舵面失去了操纵能力,需要开发新型控制律算法来研究推力矢量和推力对飞行性能的影响。本文推导和综合了推力矢量飞机运动方程,推力矢量喷管模型和传感器、作动器模型,并且提出采用后退区间优化控制算法作为研究飞机在过失速大迎角飞行条件下的鲁棒跟踪控制律。仿真验证了在飞行扩展包线中,只有推力矢量和推力配合使用才能保证飞机准确跟随驾驶指令飞行,对下一代飞机设计打下一定的基础。     

Partial stabilization-based guidance

A novel nonlinear missile guidance law against maneuvering targets is designed based on the principles of partial stability. It is demonstrated that in a real approach which is adopted with actual situations, each state of the guidance system must have a special behavior and asymptotic stability or exponential stability of all states is not realistic. Thus, a new guidance law is developed based on the partial stability theorem in such a way that the behaviors of states in the closed-loop system are in conformity with a real guidance scenario that leads to collision. The performance of the proposed guidance law in terms of interception time and control effort is compared with the sliding mode guidance law by means of numerical simulations.     

Guidance law against maneuvering targets with intercept angle constraint

This study explores the guidance law against maneuvering targets with the intercept angle constraint. The limitation of the traditional guidance law, which simply treats the unknown target acceleration as zero, has been analyzed. To reduce this limitation, a linear extended state observer is constructed to estimate the acceleration of the maneuvering target to enhance the tracking performance of the desired intercept angle. Furthermore, a nonsingular terminal sliding mode control scheme is adopted to design the sliding surface, which is able to avoid the singularity in the terminal phase of guidance. Simulation results have demonstrated that the proposed guidance law outperforms the traditional guidance law in the sense that more accurate intercept angle can be achieved.     

水力喷射径向水平井射流钻头优选试验研究

射流钻头的破岩性能对井眼深度和大小有重要影响。本文对径向水平井常用的2种射流钻头——多孔喷嘴和混合射流喷嘴采用室内试验的方法对它们的破岩规律和破岩性能进行了分析和对比。结果表明,冲击时间、喷嘴压降、喷距和围压对2种喷嘴破碎效果的规律基本相同,混合射流喷嘴的最优喷距不明显,多孔喷嘴的最优喷距为5～6倍喷嘴当量直径,多孔喷嘴的破岩性能要优于混合射流喷嘴,同时混合射流喷嘴在破碎孔径大小方面优于多孔喷嘴。本文可以为水力喷射径向水平井射流钻头的选择提供试验依据。     

平面曲柄滑块机构近似导向综合

平面曲柄滑块机构近似导向综合数值解法设计参数多(7个),求解难度大,且计算效率低下.为解决这一问题,提出了平面曲柄滑块机构导向综合的方法:将其拆分为两个双杆组,分别进行综合,并将综合结果组合以得到符合要求的平面机构,减少了单个方程组的设计参数,大大降低了求解难度.提高了计算速度.最后,推导出了两个双杆组的综合方程组,并...     

反坦克导弹三点法导引弹道仿真

导引规律是描述导弹质心运动应遵循的准则,它确定了弹道质心在空间的运动轨迹.在导弹的制导系统中,导引规律的作用是确定导弹飞行并命中目标的运动学弹道.采用一种合适的导引方法来改善导弹的制导性能,提高导弹的命中精度,一直是人们比较关心的问题.现主要通过对三点法导引规律的研究,分析各参数对导引弹道的影响.总结该法的优缺点,并提出了若干建议.     

An analytical guidance law of planetary landing mission by minimizing the control effort expenditure

An optimal trajectory design of a module for the planetary landing problem is achieved by minimizing the control effort expenditure. Using the calculus of variations theorem, the control variable is expressed as a function of costate variables, and the problem is converted into a two-point boundary-value problem. To solve this problem, the performance measure is approximated by employing a trigonometric series and subsequently, the optimal control and state trajectories are determined. To validate the accuracy of the proposed solution, a numerical method of the steepest descent is utilized. The main objective of this paper is to present a novel analytic guidance law of the planetary landing mission by optimizing the control effort expenditure. Finally, an example of a lunar landing mission is demonstrated to examine the results of this solution in practical situations.     

Sliding mode control based impact angle control guidance considering the seeker׳s field-of-view constraint

The problem of impact angle control guidance for a field-of-view constrained missile against non-maneuvering or maneuvering targets is solved by using the sliding mode control theory. The existing impact angle control guidance laws with field-of-view constraint are only applicable against stationary targets and most of them suffer abrupt-jumping of guidance command due to the application of additional guidance mode switching logic. In this paper, the field-of-view constraint is handled without using any additional switching logic. In particular, a novel time-varying sliding surface is first designed to achieve zero miss distance and zero impact angle error without violating the field-of-view constraint during the sliding mode phase. Then a control integral barrier Lyapunov function is used to design the reaching law so that the sliding mode can be reached within finite time and the field-of-view constraint is not violated during the reaching phase as well. A nonlinear extended state observer is constructed to estimate the disturbance caused by unknown target maneuver, and the undesirable chattering is alleviated effectively by using the estimation as a compensation item in the guidance law. The performance of the proposed guidance law is illustrated with simulations.