参数不确定SGCMG系统的自适应操纵律设计

在单框架控制力矩陀螺(SGCMG)系统操纵律的设计中,如果考虑框架伺服特性,往往假设系统的物理参数是确切已知的.为消除参数的不确定性对操纵性能的影响,设计了一种自适应操纵律.该操纵律可对系统物理参数进行在线估计,并能根据航天器姿态控制给出的角动量(或力矩)指令,直接计算出每个框架驱动系统所需的控制力矩.由于操纵律没有算法奇异,在SGCMG系统不出现运动奇异的情况下,可使操纵误差渐近收敛至零.同时,该操纵律对系统参数变化具有良好的适应性,且形式简单,易于实现.对应用在航天器上的某SGCMG系统的仿真结果表明,上述操纵律是可行的.     

变速控制力矩陀螺的飞轮参数与构型倾侧角优化设计

为了在保证姿控和储能功能条件下设计出变速控制力矩陀螺(VSCMG) 簇参数, 在已有动量包络分析的基础之上, 给出了考虑飞轮调速范围存在上限和下限约束条件下的动量包络空间和储能特性分析, 提出了VSCMG簇的飞轮参数和构型倾侧角的优化设计方法. 将VSCMG簇的参数优化设计问题描述为非线性、多约束、强耦合的 单目标静态优化问题, 采用序列二次规划算法求解优化问题, 获得优化的单元参数, 并计算出动量包络面, 验证了所提出优化方法的有效性.

     

Momentum unloading excessive reaction-wheel system of a spacecraft

Wide use of electromechanical actuators in attitude control systems of spacecraft is intimately connected with improvement of these actuators using unloading methods—relieving excessive momentum. As applied to electromechanical actuators of the type of reaction wheels, the problem of unloading momentum for the case of excessive flywheel system is studied. The key feature of the work is the use of arbitrary parameters in the general solution of the undefined system of linear algebraic equations as additional control parameters. For the minimum excessive flywheel system and magnetorquers of the unloading system creating the additional external moment, control algorithms are synthesized which guarantee asymptotic stability of the zero solution to model equations describing the flywheel motion. The performance of the proposed algorithms and specific features of the process of unloading momentums of the flywheels are studied, as exemplified by the controlled motion of the spacecraft in stabilization of the regime of three-axial orbital orientation.     

面向新颖成像模式敏捷卫星的联合执行机构控制方法

为满足新颖成像模式对卫星姿态快速机动或对规划姿态的高精度跟踪控制需求,本文针对金字塔构型控制力矩陀螺（Control moment gyroscopes,CMG）群与反作用飞轮为联合执行机构的挠性敏捷卫星,提出一种融合以Legendre伪谱法实现卫星姿态及CMG群框架角速度最优规划的前馈控制、以非线性模型预测控制（Nonlinear model predictive control,NMPC）实现最优轨迹反馈跟踪的复合控制方法.在前馈控制律设计中,充分考虑了CMG群的力矩输出能力、奇异性及振动抑制性能等约束,规划获得了最优的CMG群框架角速度、卫星的姿态角及角速度.在反馈控制律设计中,以飞轮输出力矩能力、姿态机动快速性及能量为约束,设计了具有滚动优化思想的跟踪算法,补偿由于初始状态及转动惯量偏差等带来的控制误差.研究结果表明,在转动惯量存在偏差情况下,本文的控制方法仍是有效的,且表现出较强的鲁棒性.     

知识化制造环境下航空发动机装配车间自进化

针对产品动态到达的航空发动机装配车间, 对知识化制造系统的自进化问题进行研究. 将自进化的思想应用于该装配车间, 提出了知识化制造环境下该装配车间自进化问题的求解算法. 根据双层规划理论, 建立了系统在每个决策时刻静态决策问题的一般数学模型, 并设计了一种基于可行域搜索的双层遗传算法(FR-BiGA) 对模型进行求解. 仿真结果验证了该模型与算法的有效性和可行性, 且实验数据表明, 自进化的系统具有相对较优的生产性能.

     

Controllability of Spacecraft Attitude Using Control Moment Gyroscopes

This technical note describes an application of nonlinear controllability theory to the problem of spacecraft attitude control using control moment gyroscopes (CMGs). Nonlinear controllability theory is used to show that a spacecraft carrying one or more CMGs is controllable on every angular momentum level set in spite of the presence of singular CMG configurations, that is, given any two states having the same angular momentum, any one of them can be reached from the other using suitably chosen motions of the CMG gimbals. This result is used to obtain sufficient conditions on the momentum volume of the CMG array that guarantee the existence of gimbal motions which steer the spacecraft to a desired spin state or rest attitude.      

Stabilization of polytopic delay difference inclusions via the Razumikhin approach

Polytopic delay difference inclusions (DDIs) have received increasing attention recently, mostly due to their ability to model a wide variety of relevant processes, including networked control systems. One of the fundamental problems for DDIs that poses a non-trivial challenge is stabilization. This paper embraces the Razumikhin approach and provides several solutions to the stabilization problem as follows. Firstly, a method to synthesize a control Lyapunov–Razumikhin function (cLRF) is presented for unconstrained DDIs. Secondly, for constrained DDIs, a receding horizon controller based on the cLRF for the unconstrained system is proposed, along with a closed-loop stability analysis. Thirdly, it is shown that a tractable implementation of the developed control algorithm can be attained even for large delays, by means of an on-line Minkowski set addition. An advantageous feature of the developed methodology is that all the synthesis algorithms can be formulated as a low complexity semi-definite programming problem for quadratic cLRF candidates. A comparison with alternative synthesis methods demonstrates the advances provided by the developed theory.     

双层规划在灾后应急物资调度中的应用综述

为了减少财产损失和人员伤亡、提高灾民满意度,基于双层规划理论,从应急救援角度出发,对突发灾害事件下的应急物资调度问题进行综述。围绕应急物资调度,从灾后应急现状、应急物资选址—分配、不同约束下的应急物资调度及双层规划和群智能优化算法在应急物资调度中的应用等方面进行梳理和讨论。结果表明,关于灾后应急物资调度的研究,目前主要关注单级应急网络结构,且模型的目标函数和约束条件与实际情况存在着出入,结合应急物资调度实际特征提出改进建议;考虑两级应急网络结构,进而构建双层规划模型,实现上下级目标的联合优化。     

A global optimization algorithm for solving the bi-level linear fractional programming problem

In this paper, we obtain the solution to bi-level linear fractional programming problem (BLFP) by means of an optimization algorithm based on the duality gap of the lower level problem. In our algorithm, the bi-level linear fractional programming problem is transformed into an equivalent single level programming problem by forcing the dual gap of the lower level problem to zero. Then, by obtaining all vertices of a polyhedron, the single level programming problem can be converted into a series of linear fractional programming problems. Finally, the performance of the proposed algorithm is tested on a set of examples taken from the literature.     

Sensitivity shaping with degree constraint by nonlinear least-squares optimization

This paper presents a new approach to shaping of the frequency response of the sensitivity function. In this approach, a desired frequency response is assumed to be specified at a finite number of frequency points. A sensitivity shaping problem is formulated as an approximation problem to the desired frequency response with a function in a class of sensitivity functions with a degree bound. The sensitivity shaping problem is reduced to a finite-dimensional constrained nonlinear least-squares optimization problem. To solve the optimization problem numerically, standard algorithms for an unconstrained version of nonlinear least-squares problems are modified to incorporate the constraint. Numerical examples illustrate how these design parameters are tuned in an intuitive manner, as well as how the design proceeds in actual control problems.     

不确定情形下在线多源多属性反向拍卖双边协商决策

针对现实中存在的带有协商交互的在线多源多属性反向拍卖(OMSMARA)情形,同时考虑到买卖(采供)双方面临的不同方面的不确定性,综合利用双层规划理论和模糊理论研究不确定情形下OMSMARA双边协商决策问题.首先,基于问题描述和适当假设,建立一个新的带有协商交互的模糊混合整数双层规划(FMIBLP)模型,并基于增广模糊最小最大决策方法进行模型的精确转化;其次,考虑到问题模型的特点以及粒子群算法(PSO)的优越性,提出基于修正PSO的双层分布迭代算法(PSO-BLDI)用于模型求解;然后,通过数值算例和对比分析展示所建模型的可行性以及所提出算法的有效性;最后,通过敏感性分析研究相关参数变化对模型求解结果的影响,进一步表明所提出模型的合理性与决策方法的有效性.     

Constrained optimal control of switched systems based on modified BFGS algorithm and filled function method

In this paper, we consider an optimal control problem of switched systems with a continuous-time inequality constraint. Because of the complexity of this constraint, it is difficult to solve this problem by standard optimization techniques. To overcome this difficulty, the problem is divided into a bi-level optimization problem involving a combination of a continuous-time optimal control problem and a discrete optimization problem. Then, a modified Broyden-Fletcher-Goldfarb-Shanno algorithm and a discrete filled function method is first proposed to solve this bi-level optimization problem. Finally, a numerical example is presented to illustrate the efficiency of our method.     

单轮电机失效时四轮轮毂电动汽车各驱动模式转向特性研究

文章在对轮胎侧偏特性和轮胎力研究的基础上,提出了四轮轮毂电动汽车四种驱动模式的转向力矩分配问题;通过数学分析,将此问题转化为一个有约束条件的最优化求解问题,接着使用MATLAB优化工具箱,并采用有效集算法对此优化问题进行求解,最终解决了单轮电机失效时四种驱动模式的选择问题,为改善单轮电机失效时四轮轮毂电动汽车的转向特性,防止车辆侧滑失稳提供了理论依据;最后采用汽车动力学仿真软件TESIS DYNAware对所提理论的正确性进行了仿真验证。     

基于Pareto支配的双目标优化求解非线性双层规划问题

双层规划问题是一类具有双层递阶结构的系统优化问题。采用Pareto支配的双目标优化策略求解非线性双层规划问题。利用K-T条件把双层规划问题等价转化单层规划问题,进而结合约束部分建立可行性度量目标形成双目标规划问题。在基本的差分进化算法框架中融入非负的最小二乘曲线拟合判断候选解的可行性,构造基于动态概率的Pareto支配选择策略挑选下一代个体,解决种群容易陷入局部最优的缺陷。15个标准函数的测试结果对比显示,该算法在求解非线性双层规划问题中具有较好的全局寻优能力、较低的计算复杂度、较强的稳定性和适用性,可以获得全局最优解。     

高速公路网入口流量控制的双层规划模型及算法

建立双层规划模型用于解决高速公路网的入口流量控制问题。提出了一种结合遗传算法和Aloplex算法的新算法——GAA算法来求解双层规划问题。实验结果表示，GAA算法在求解双层规划问题上优于遗传算法；分车型测算得出进入路网的流量使上层目标函数值更小（相对于单车型情况），并且使路网利用程度得到进一步的提高。     

上层含约束条件且具有模糊决策变量的二层多随从线性规划

提出并研究了一类上层含约束条件且具有模糊决策变量的二层多随从线性规划模型,利用结构元理论证明了该模型最优解等价于上层含约束条件的二层多随从线性规划模型最优解,利用Kuhn-Tucker方法得到了该模型最优解,并通过数值算例验证了该方法的可行性。     

柔性车间生产排产调度优化方法

为满足柔性制造企业在车间生产中合理安排生产排产调度的需要,提出柔性车间生产排产调度优化方法。首先,通过分析车间生产排产问题的特点,制定满足车间应用需求和各种资源限制的生产排产总体流程,从而设计基于约束条件的生产对象关系模型;其次,提出一种动态策略差分进化算法,根据个体之间的拥挤度动态选择变异策略,设计基于工序位置的编解码方案,其能快速有效地进行求解,从而得到最佳调度方案,提高设备运行效率,实现资源利用的最大化;最后,通过6个标准测试函数、FT6-6测试问题及生产调度应用实例验证了算法的有效性。     

Bi-level programming modeling and hierarchical hybrid algorithm for antimissile dynamic firepower allocation problem with uncertain environment

Aiming at the shortcomings of antimissile dynamic firepower allocation (ADFA) researches under uncertain environment, the fuzzy chance-constrained bi-level programming model with complex constraints is proposed by introducing the uncertain programming theory. Firstly, maximization cost-effectiveness ratio and earliest interception time as the upper and the lower objective functions of the model, respectively, are used. In order to close to the battlefield environment, the model constraint includes interception time window, effective damage lower bound and intercept strategy, etc. Secondly, a particle coding scheme and repairing scheme are given with hierarchical structure for multi-constrained bi-level ADFA problem. Furthermore, the improved variable neighborhood PSO algorithm with convergence criterions and the PSO algorithm with doubt and repulsion factor (PSO-DR) are effectively combined. On these bases, the hierarchical hybrid fuzzy particle swarm optimization algorithm is presented with fuzzy simulation technique. Finally, the results of comparison show the proposed algorithm has stronger global searching ability and faster convergence speed, which can effectively solve large-scale ADFA problem and adapt to the requirements of real-time decision.     

欠驱动刚体航天器姿态运动规划的遗传算法

研究欠驱动刚体航天器姿态的非完整运动规划问题．航天器利用3个动量飞轮可以控制其姿态和任意定位,当其中一轮失效,航天器姿态通常表现为不可控．在系统角动量为零的情况下,系统的姿态控制问题可转化为无漂移系统的运动规划问题．基于优化控制理论,提出了求解欠驱动刚体航天器的姿态运动控制遗传算法,并且数值仿真表明：该方法对欠驱动航天器姿态运动的控制是有效的．     

Optimal decision making in multi-product dual sourcing procurement with demand forecast updating

In this paper, we will investigate a buyer's decision making problem in procuring multiple products, each treated as a newsvendor, from two markets. The contract market has a long lead time, a fixed wholesale price and resource constraints. While the spot market has an instant lead time and a highly volatile price. The purchasing decision at the spot market can be made near the beginning of the selling season to take the advantage of the most recent demand forecast. The buyer needs to determine the purchasing quantity for each product at the two markets to maximize the expected profit by trading off between the resource availability, demand uncertainty and price variability. The procurement decision making is modeled as a bi-level programming problem under both a single resource constraint and under multiple resource constraints. We show that this bi-level programming problem can be formulated as a single-level concave programming problem. We then develop a sequential algorithm which solves for a linear approximation of the concave programming problem in each iteration. This algorithm can be used to solve a real world problem with up to thousands of kinds of products, and is found to be highly efficient and effective.