A 3D Model of One-Legged Hopping Machine

The paper models the spatial motion of a hopping machine with allowance for the inertial properties of its leg. A control system is synthesized and a program trajectory is determined in view of the collision processes accompanying touchdowns. The synthesis procedure is based on optimization of periodic systems. The results from numerical simulation of the hopper's nonstationary motion are demonstrative of the high efficiency of the control system     

Control of the Nonstationary Motion of a Hopping Machine (Path Tracking)

The problem on control of the nonstationary motion of a hopping machine is solved. It is shown that similarly to a walking machine, this problem can be reduced to finding a periodic solution of the discrete Riccati equation. The simulation results are indicative of the efficiency of the algorithm proposed     

单足机器人周期跳跃控制的虚拟约束方法

研究单足机器人周期跳跃控制问题.弹簧支撑倒立摆模型可以比较准确地描述动物的跳跃行为,但无控制的自然跳跃抗干扰能力较差,一般采用轨迹跟踪控制方法实现单足机器人周期跳跃.当系统存在比较大的误差时,传统的时间轨迹跟踪控制方法存在明显的不足.引入虚拟约束技术,采用基于空间路径跟踪的控制方法可以克服时间轨迹跟踪的不足.采用点足机器人模型,并通过控制腿伸缩的方式为系统提供动力,将跳跃过程分为地面摆动和腾空飞行两个阶段,并通过起飞和着陆两个事件完成两个阶段之间的转换,整个系统模型属于欠驱动非光滑动力学系统.根据简化的动力学方程获得系统的虚拟约束解析表达式,并采用部分反馈线性化方法结合PD控制设计系统的控制律.分析了系统的混合零动力学方程,并证明了闭环系统的临界稳定性.仿真结果表明,提出的控制方法可以实现单足机器人的周期跳跃控制,并且对外部干扰具有较强的鲁棒性.     

基于遗传算法参数整定的方位保持仪温控系统

遗传算法是一种高效的模拟生物进化过程的全局随机化搜索优化方法，它可直接得到所求解问题的全局最优解。针对方位保持仪，提出了一种分段参数设置与级间控制相结合的三级温控方案，并基于遗传算法对PID控制参数进行了优化整定。同时介绍了整个温控系统的软件实现。大量试验证明该控制策略接近最优，达到了战技指标要求。     

A Note on a Model Hopping Machine

A model of a statically unstable (one-legged) hopping machine is discussed. It is used to analyze whether and how well the control algorithms for systems with variable constraints can be employed in the engineering implementation of this machine. The results obtained indicate that the control algorithms make it possible to create a functioning machine with relatively simple components. The dynamical characteristics of this hopping machine are such that it can, for example, double the horizontal speed in two to three hops. This fact is interesting because a linear controller controls a nonlinear object.     

应用遗传算法求解二维扩压器壁面速度最优分布

将遗传算法应用于求解透平机械中的二维扩压器壁面最优化速度分布，该方法可以容易的求解出既满足在扩压器出口流动速度极小又保证壁面边界层不发生分离的最优速度分布。用该方法求取著名的Ｓｔｒａｔｆｏｒｄ实验条件下的二维扩压器最优速度分布，所得结果与该实验吻合良好。     

A Note on a Walking Machine Model

The paper continues studies intended to find out whether it is possible to create a prototype walking machine with relatively simple components. In this connection, the control problem is solved for a two-dimensional model of biped machine. It has a torso and two telescopic legs. Each leg includes a ponderable section of constant length and an imponderable section of variable length. The machine, regarded as a system with variable constraints, implements a single-stance gait (one stance leg at a time) with a step of constant duration. The contact of the swing leg with the ground is analyzed within the framework of Carnot's theorem (perfectly inelastic impact). It is assumed that the force developed in the stance leg is due to the deformation of the leg's spring and that this deformation can be controlled. An algorithm is proposed to synthesize a control system that takes into account collisions occurring at reverse of the roles of the legs. This algorithm is based on methods of optimizing periodic systems. The algorithm is compared with approaches used by other authors     

变厚度多层介质结构的一种三维数值半解析方法

应用复合材料层合结构分理论思维，建立起以样条函数、级数及插值相结合的新型三维数值半解析算法，以期解决复材呈变厚度结构的变形及内力分析，并作为该类型结构优化设计的高精度的内核计算工具。本文方法克服了一般半解析方法对解析函数的过分依赖性，在原始数据准备、计算规模、数值精度、收特性及稳定性诸方面都较有限元方法有显著改善；特别对复材层合结构的变厚度区段，无需主任何假设，从而为解特殊类型问题提供了极好的分析     

A Simplified Optimal Control Method for Homoclinic Bifurcations

A simplified optimal control method is presented for controlling or suppressing homoclinic bifurcations of general nonlinear oscillators with one degree-of-freedom. The simplification is based on the addition of an adjustable parameter and a superharmonic excitation in the force term. By solving an optimization problem for the optimal amplitude coefficients of the harmonic and superharmonic excitations to be used as the controlled parameters, the force term as the controller can be designed. By doing so, the control gain and small optimal amplitude coefficients can be obtained at lowest cost. As the adjustable parameter decreases, a gain of some amplitude coefficient ratio is increased to the highest degree, which means that the region where homoclinic intersection does not occur will be enlarged as much as possible, leading to the best possible control performance. Finally, it is shown that the theoretical analysis is in agreement with the numerical simulations on several concerned issues including the identification of the stable and unstable manifolds and the basins of attraction.     

结构优化的GA算法

本文提出了一种用于结构优化的具有动态种源空间的ＧＡ算法，这种ＧＡ算法可以与其它结构优化方法如齿行法结合起来处理结构优化问题。这种ＧＡ具有很好的鲁棒性和较高的效率，可作为一个黑箱处理相当广泛的结构优化问题。     

Aerodynamic optimization of 3D wing based on iSIGHT

A method for combining the CFD software,Fluent,with the iSIGHT design platform is presented to optimize a three-dimensional wing to ameliorate its aerodynamics performance.In the optimization design,two kinds of genetic algorithms,the Neighborhood Cultivation Genetic Algorithm（NCGA）and the Non-dominated Sorting Genetic Algorithm（NSGAII）,are employed and the Navier-Stoke（N-S）equations are adopted to derive the aerodynamics functions of the 3D wing.The aerodynamic performance of the optimized wing has been significantly improved,which shows that the approach can be extended and employed in other cases.     

航天器太阳阵伸展过程最优控制的遗传算法

本文讨论航天器太阳阵伸展中航天器姿态的最优控制问题。利用动量矩守恒原理导出带太阳阵航天器的动力方程,指出了系统的非」完整约束性质。将航天器太阳阵展开过程中主体姿态控制问题转化为非线性系统最优控制问题。厚优控制中引入遗传算法,替代传统的牛顿迭代方法。提出基于遗传算法的非完整运动规划最优控制算法。通过数值仿真表明,该方法对太阳阵伸展过程航天器姿态控制是有效的。     

改进单向搜索遗传算法的工程结构优化设计

本文基于规范规定的约束条件和各项技术标准要求，建立了离散变量结构优化模型。针对遗传算法在迭代过程中经常出现未成熟收敛、振荡、随机性太大和迭代过程缓慢等缺点，提出一种新的遗传算子单亲遗传算子，用于对遗传算法的改进。并提出一种离散变量结构优化设计的单向搜索算法与遗传算法结合在一起解决问题。优化设计结果表明，这种改进单向搜索遗传算法的收敛特性得到了很好的改善，即发挥了单向搜索算法局部搜索能力强的特点，又发挥了遗传算法全局性好的特点。该方法是一种有效的工程结构优化设计方法。     

基于分析传函的有源力控FLMS算法研究

针对结构振动和声辐射有源控制中对误差传函现有建模方法的不足 ,本文对该系统的物理通道进行了分析建模 ,形成了基于分析传函模型的 FLMS算法 ,该分析传函模型中充分包含了结构的振动模态信息 ,无论激励力源是单频还是宽频激励力源 ,该模型都可以在实施 FLMS算法之前确定所需参数。随后在该算法的计算机模拟实验中 ,通过与时延估计法的比较 ,表明该方法扩大了步长因子的取值范围 ,扩大了收敛域 ,该模型的建立为有效实施有源控制的自适应算法提供了一条新的途径。     

基于遗传算法的结构支撑位置优化

采用整数编码、实数编码、种群隔离机制、算术杂交、非均匀随机变异等新理论设计了一种广义遗传算法,并将该算法应用于结构支撑位置优化问题。数值算例表明,该方法能够很好地求解支撑具有弯曲刚度的结构支撑位置优化问题,对于一般支撑位置优化问题具有较强的适用性。     

Maneuvering Aspects and 3D Effects of Active Airfoil Flow Control

An active flow control experiment was conducted on a cropped NACA 0018 airfoil to study 3D effects and maneuverability aspects made possible by a segmented actuation system installed in the airfoil. The 14 piezo-fluidic actuators were installed at the corner of the cropped region, inclined at 30° to the local surface, facing downstream. Operating all actuators at unison significantly increased lift and generated a pitch-down moment. Operating all actuators at the same magnitude but varying the phase along the span generated larger lift-increment, with respect to the uniform phase excitation. Significant rolling moment can be generated when only half-span of the wing is actuated. The latter effect, as indicated by the 3D pressure distribution, persists to the leading edge even though the excitation was introduced close to the trailing edge. When a pair, out of the possible fourteen actuators is not operating, very little of the control authority is lost. This is an important finding when issues like fault tolerance and robustness of fluidic-piezo actuators are considered.     

改进的遗传算法在连续体结构多目标拓扑优化中的应用

连续体结掏多目标拓扑优化是结构优化领域中的一个较难的研究课题.本文提出了一种改进的SPEA2多目标优化算法.该算法中采用数学形态学中的四方向链码的编码方式进行结构拓扑表达,使产生的拓扑结构清晰且无异议,完全消除了模糊的拓扑边界和棋盘格现象.提出了"质量向量"的概念,用以量化两个结构拓扑之间的相似性,从而使得不同结构拓扑之间的相似性比较成为可能.同时还将机器学习中的范例学习的思想融入到新算法中,利用前面的有限元分析结果对后来的结构分析进行指导,剔除了很多不必要的重复的计算,从而使算法的总计算量大幅度地减少.将新算法应用于悬臂和简支两类深梁的多目标拓扑优化,获得了高质量的Pareto最优解,且具有很好的分布.     

一种基于二次优化的改进圆锥算法

提出了一种改进的圆锥优化算法,对传统圆锥优化算法的周期项进行了二次优化.首先,根据经典圆锥运动建立了二次优化的误差准则;其次,给出了推导二次优化补偿系数以及相应的残留误差的一般方法;最后,在不同的经典圆锥运动环境下对三例改进算法的姿态解算误差进行了仿真验证.结果表明,通过改进的四子样和五子样算法得到姿态解算精度与通过旋转矢量变化量的理想值得到的结果几乎完全一致.此外,由于比改进的五子样算法少一次叉乘和两次加法运算,而且仿真速度大约快14％,所以改进的四子样算法更值得推荐采用.     

简单周期结构波传播主动控制研究

研究了在梁结构插入压电材料的周期结构波传播的一般规律。以梁的弯曲波传播方程的解析解为基础，进一步分析了简单周期结构的波传播的一些固有特性。并在此基础上，以压电材料作为作动器，采用主动控制方法研究了调整结构传播波的带通、带阻的频率范围可行性和有效性。     

基于遗传算法的仿真转台控制器优化设计与应用

针对仿真转台系统的时变性、模型的不确定性等特点，提出采用基于遗传算法的PID自适应控制器，实现控制器参数的在线自寻优。试验结果表明，该控制算法具有很强的鲁棒性、抑制外界干扰性和良好的动态性能。