联合收割机脱粒滚筒恒速智能控制器设计

研究了轴流式联合收割机的控制问题,给出了联合收割机脱粒滚筒的数学模型,介绍了基于模式识别的智能控制原理,建立了联合收割机脱粒滚筒恒速控制模型,设计了基于模式识别的智能恒速控制器.应用Matlab/Simulink进行了控制器仿真,其结果表明,将基于模式识别的智能控制应用于联合收割机脱粒滚筒的恒速控制,其过渡过程平稳、响应速度快、无超调、无振荡并且无稳态误差.     

Approximation of solutions of generalized equations of Hammerstein type

Let $H$ be a real Hilbert space. For each $i=1,2,\dots ,m$, let $F_i,K_i:H\to H$ be bounded and monotone mappings. Assume that the generalized Hammerstein equation $u+{\sum }_{i=1}^m{K}_i{F}_{i}u=0$ has a solution in $H$. We construct a new explicit iterative sequence and prove strong convergence of the sequence to a solution of the generalized Hammerstein equation.     

Systems of generators for ideals of algebra of convergent differential series

Differential algebra of convergent power series that depend on an arbitrary finite number of variables is considered. The concept of a passive family of generators is defined for a differential ideal of this algebra. It is a further extension of the concept of the Groebner basis. The theorem that allows checking whether a family of generators is passive and ensures that the point solution of an infinite system of equations exists and is unique in this algebra is proved.     

基于语义事务分解的可串行性

数据库应用中长事务的出现严重降低了系统的性能，一些研究者为解决这一问题提出了利用事务的语义信息对事务进行分解的方法，但所得结论仍然存在缺陷．本文从用户定义的后续集出发给出了正确步进串行历史的概念，可以很容易证明正确步进串行历史是用户可接受的正确历史，并以此作为判定一个历史是否正确的基础．重后，证明了当用户给出的后续集满足约束2时，优化前驱图的无环性是判定一个正确历史的充要条件．     

基于兴趣区检测的远距离机场目标识别研究

典型目标的检测识别是精确制导武器的关键技术之一，具有广泛的应用。根据远距离前视红外机场目标图像的特性，文章提出并实现了一种利用边缘线段群特征检测感兴趣机场目标区域，并进一步分割、识别潜在目标的新算法。仿真实验结果证实算法是合理、有效的。本文的算法结构简单、适应性广、适合于实时处理，具有广泛的应用前景。     

Stability properties of equilibria of classes of cooperativesystems

This note deals with the constant control problem for homogeneous cooperative and irreducible systems. These systems serve as models for positive systems. A necessary and sufficient condition for global asymptotic stability of the zero solution of this class of systems is known. Adding a constant control allows to shift the equilibrium point from zero to a point in the first orthant. We prove that for every nontrivial nonnegative control vector a unique nontrivial equilibrium point is achieved which is globally asymptotically stable if the zero solution of the uncontrolled system is globally asymptotically stable. In addition a converse result is provided. Finally a stability result for a particular class of Kolmogorov systems is established. We compare our main results to those in the literature     

核ICA在电流传感器相位差监测中的应用

介绍了核独立分量分析(ICA)的基本原理和算法,并将其用于对电流传感器输出的混合信号进行分离,通过比较分离出的单频测试信号输入前后的相位差,来标定传感器本身的相位差对其检测对象的影响。此外,还采用最大似然法对核ICA的分离效果进行评价。实验证明:在输入信号的信噪比为18.73dB的情况下,核ICA分离出的信号与源信号相位差在0.002 rad以内,达到了实际应用中所要求的误差范围。     

短时公交客流的弦不变量预测方法

短时公交客流预测是智能公交系统动态调度的基础.文中根据短时公交客流数据特性,提出基于弦理论的短时公交客流预测方法,模拟弦结构建立弦不变量客流预测模型(SI-PFPM),并采用遗传算法优化SI-PFPM中各参数.提出基于动态时间弯曲距离的仿射传播(AP)聚类算法,对短时公交客流时间序列进行聚类分析.利用SI-PFPM预测聚类子集数据,并分析预测残差,验证SI-PFPM可以预测短时公交客流的假设成立.最后将SI-PFPM的预测性能与现有方法进行对比分析,验证SI-PFPM对短时公交客流预测的有效性.     

A method of reducing the number of members of the committee systems of linear inequalities

The problem of discriminant analysis under mild conditions is reduced to a system of linear inequalities. However, this system can turn out to be inconsistent, which happens rather frequently. This is when the method of committees is used. The quality of a committee is improved as the number of its members drops. A method of reducing the number of members of committees, if this is fundamentally possible, is considered.     

Current optimization of search of objects for the model of distributed Poisson flow of their appearance

The problem of current optimization of object search when their appearance is simulated by random flow regularities is considered. The equation of evolution in time is obtained for the density of non-normalized probabilistic measure that gives probabilistic characteristics of the search. The optimal control law is synthesized for the search, with its properties analyzed. An example is given.     

磁力矩器测试设备中关键技术的研究

磁力矩器被广泛用于卫星的姿态控制分系统中[1,2],所以其测试技术的研究必不可少。通过对磁力矩器原理进行分析后发现,要对磁力矩器进行有效的测试,难点是在可变高共模的条件下高精确度、实时地监测磁棒的微小工作电流和电源电流。在磁力矩器测试设备中,要求电源的电压是可变的,再加上电阻的实际阻值和标定的阻值之间存在误差,造成差分放大器的正负端的不对称。以上特点会引入一种误差,但是经过分析发现这种误差是可校正的。所以针对上述问题提出了一种解决方法,补偿了由上述原因引起的误差。该方法简单,容易实现。经试验证明,提出的方法能够明显提高测量精度,满足磁力矩器测试的需要。     

复杂性算法在图像景深扩展中的应用研究

由于光学系统受景深小的物理性能限制,对纵向变化范围较大的物体,所拍图片为局部清晰。利用Kolmogorov复杂性测度来度量不同聚焦层面形成的序列图像中对象的局部清晰程度,将序列图像聚焦清晰的部分提取并合并出一幅全清晰图像,实现景深扩展,得到清晰的全景深图像。实验证明,将复杂性测度应用于景深扩展,具有广泛的应用前景。     

斜拉索主参数共振的稳定性分析

研究轴向激励下斜拉索的主参数共振的稳定性问题．考虑拉索垂度和几何非线性的影响,导出了拉索在轴向激励下的非线性参数振动方程．利用多尺度方法研究了斜拉索的主参数共振问题,并对其稳态解的稳定性作了较详细的分析．对斜拉索的主参数共振进行了数值模拟,得到了不同阻尼、初始条件及激励幅值作用下拉索的时程曲线．结果表明：斜拉索的固有频率与外激励参数对斜拉索稳态解的个数及其稳定性都存在直接影响,从而对斜拉索的参数设计起到了指导作用．     

Problems of Evolution of Rotations of a Rigid Body under the Action of Perturbing Moments

The rotatory motion of a nearly dynamically spherical rigidbody, which contains a viscoelastic element, is considered. This elementis simulated by a moving mass, connected by a spring and damper to thepoint, situated on one of a principal axis of inertia. The smallparameters caused by the proximity of moments of inertia and thepresence of moving mass are considered to be of the same order. Thespherical coordinates defining the position of the angular velocityvector are introduced. The system of differential equations is obtainedand investigated, the special cases of motion are considered. Theauthors investigate perturbed rotational motions of a rigid body,similar to the regular precession in the Lagrange case, under the actionof the moment that is slowly changing in time and the restoring momentdepending on the angle of nutation. In two problems it is assumed thatthe angular velocity of the body is large and its direction is close tothe axes of dynamic symmetry. In the first problem it is assumed thattwo projections of the vector of the perturbing moment onto principalaxes of inertia of the body are small as compared to the restoringmoment, while the third one is of the same order of the magnitude as themoment in question. In the second problem it is assumed that theperturbing moments are small as compared to the restoring one. Averagedsystems of equations of motion are obtained and investigated in thefirst and the second approximations. Examples are considered.     

多维数据实视图的动态选择

提出了多维数据中实视图的动态选择方案.其基本思想是由系统跟踪查询的分布情况,并据此动态地调整实视图集合.具体实现了该方案,并证明了在一定条件下,单次选择算法的效果与最优效果的差具有一定的上限.实验结果表明,动态方案的效果优于已有的其他选择方案.     

On time-optimal control of a sequence of projects of activitiesunder time-variable resource

A sequence of k projects of independent activities, each project composed of activities available for realization at the same time, is considered. It is assumed that the activities are continuous dynamical systems with dynamics that depend continuously on the alloted amounts of the resource and that the initial and terminal states are fixed. The problem is to allocate the time-variable renewable, continuously divisible resource (e.g. power, fuel flow, approximate manpower) to the activities in order to minimize the performance time of the sequence of projects. A solution is presented that is based on the notion of the set of reachable states under the assumption that the allowable level of the total usage of the resource is piecewise constant. Necessary and sufficient optimality conditions are stated in terms of the performance time, and the existence of the optimal control is proved. An algorithm for the time optimal control is proved. An algorithm for the time-optimal resource allocation is derived and an example is given to illustrate the approach     

信号处理系统高性能网络关键技术的研究

新型通用嵌入式信号处理系统是基于分组交换网络实现的。在嵌入式系统中,其中一个关键的问题是设计高性能和高可靠性的分组网络,解决多个处理器高速互连,进一步提高信号处理系统的整体性能。RapidIO协议是商业联盟协会为了解决嵌入式系统高速互连的问题于2001年3月提出的,该文根据协议的要求和应用范围,以及信号处理系统的特点,将该协议用于解决信号处理系统高速互连的问题,提出了一种能适用于RapidIO分组交换网络不同拓扑结构的路由策略,最后运用概率模型对此分组交换网络的一些性能进行了比较详细的分析。该文通过对实现RapidIO协议关键技术的研究和对系统性能的分析,对建立基于RapidIO协议的通用高速信号处理系统具有重要的意义。     

多体动力学在汽车前轮定位参数分析中的应用

以某轿车的前悬为例,基于多体动力学理论,利用拉格朗日乘子法,采用虚拟样机技术,借助MSCAdams/car软件,建立某轿车前悬的多体动力学仿真模型,深入地分析前轮定位参数随车轮跳动的变化关系.结果和实测值、理论值相一致,表明该分析方法对产品的优化设计、缩短产品的研制周期具有重要的实际意义.     

Organization of the non-uniqueness of a canonical structure of linear multivariable systems

This paper is concerned with organizing the non-uniqueness of the canonical structure of a class of linear time-invariant multivariable systems in such a way as to provide an efficient tool in control system design. A phase-variable block form of state equations is used to describe the system class in the transformed coordinates. The transformation procedure is characterized by an arbitrary parameter (in the form of a submatrix) which adds an attractive degree of freedom in the solution of practical problems. As a demonstration, the procedure is applied to synthesize a minimum-time deadbeat controller for linear discrete-time systems. A family of controllers, not identifiable by earlier approaches, is developed and that controller which additionally minimizes a control energy criterion is determined. A numerical example is provided to illustrate the different aspects of this work.     

基于纹理方向整体分布特征的台风自动识别方法

为实现卫星云图上台风的自动识别，提出了一种基于纹理方向整体分布特征的台风云系图象自动识别方法，通过引入矢量矩的概念来表现图象纹理整体分布规律，该识别方法采用全局搜索方式，将一窗口在整幅图象上滑动，首先计算出窗口图象内各点的纹理方向，进而得出窗口图像的矢量矩，将矢量矩与阈值比较来判整幅图象是否为台风云系图像，实验结果表明，该方法能够识别不同类型和不同发展阶段的台风云系图象，能够很好地将台风云系与其他干扰云系区分开，具有较广泛的适应性和较高的识别率。