足球机器人守门员防守策略研究

分析了足球机器人比赛中防守特点,提出了一种根据区域划分的防守策略算法。分析了可能遇到的几种情况,针对不同的现场局面形式,给出不同的防守策略。     

存在视觉盲区的小型无人机群自主控制

小型无人机自身负载小,所能携带的通信设备比较有限,可以安装鱼眼镜头作为相互之间的视觉通信设备以扩大无人机的可视范围,但鱼眼镜头仍然存在视觉盲区.为了解决这一问题,论文提出了存在视觉盲区的小型无人机群自主控制算法.论文的主要思想是,首先,对无人机的飞行时的运动状态进行分析,进而建立其飞行时的运动学方程;其次,针对无人机飞...     

一种基于局部变换处理的干扰抵消后置处理方法

针对基于阻塞矩阵方式抵消干扰产生的探测影区问题,提出了一种基于局部变换处理的干扰抵消后置处理方法。首先根据干扰抵消方位对接收阵拾取数据进行线性变换处理,合成一组新数据;其次采用空间谱合成方法对新数据进行变换处理,得到空间各方位对应空间谱;然后采用局部变换处理方法,提取空间谱基底变化量;最后采用空间谱基底变化量对空间谱进行均衡处理,降低探测影区。数值仿真和数据处理均表明,该方法通过对干扰抵消后空间谱进行局部非线性均衡处理,减小了空间谱基底变化量,将探测影区缩小到了3°以内,改善了基于阻塞矩阵方式干扰抵消方法。     

智能称量系统与死区PID控制在烧结配料中的应用

烧结生产实践证明,烧结配料发生偏差是影响烧结过程正常进行和烧结矿产质量的重要因素。因此,精确配料是十分重要的。针对实际需要,将智能称量系统与带死区PID控制算法应用于对烧结配料系统的控制中,并详细介绍烧结配料系统运用智能称量系统与带死区PID控制算法来实现精确配料的控制过程。实践证明,该技术的应用取得了很好的控制效果,适合现场实际应用。     

Factors Influencing High Temperature Thermo Plasticity of BNbRE Steel at the Third Brittle Zone

In view of fine cracks occurred on the surface of BNbRE continuous casting slabs for heavy rail in the practiced production, the effect of two factors, i. e. deformation temperature, deformation velocity, on thermo plasticity of BNbRE steel at the third brittle zone was quantitatively investigated on GLEEBLE-1500D thermal-mechanical simulator after measuring the RA-T curve of BNbRE steel. The results provide experimental data for optimizing the technology of continuous casting secondary cooling zone and avoiding the occurrence of fine surface cracks.     

电弧炉电极调节系统的自适应死区补偿控制

电弧炉电极调节系统存在死区非线性,这将给控制系统带来稳态误差,甚全会造成系统不稳定.为此,针对断点不对称且斜率不相等的死区特性,提出一种自适心死区补偿方法.通过引入死区逆非线性环节,并在线更新未知的死区逆参数,达到完全补偿死区的效果.利用Lyapunov方法证明了参数估计误差的收敛性.仿真结果验证了所提出方法的有效性.     

Microstructure Formation in AlSi7Mg Alloys Directionally Solidified in a Rotating Magnetic Field

To produce high stressed automotive components like engine frames and cylinder heads in foundry industry often AlSi7Mg alloys are used. During mould filling and casting melt flow affects the development of the microstructure, which defines the mechanical properties. In this paper the microstructure formation in AlSi7Mg0.3 and AlSi7Mg0.6 alloys during directional solidification is investigated. To induce a forced melt flow a rotating magnetic field is applied. For that purpose a Bridgman‐type gradient furnace is equipped with a rotary ring magnet. For detailed investigation of the shape of the solid‐liquid interface and the primary dendrite spacing a decanting device is used. As a result, the forced melt flow substantially changes the dendritic solidification microstructure. The rotating magnetic field generates a radial secondary flow in and ahead of the mushy zone, which causes an enrichment of eutectics in the centre of the samples. At lower solidification velocities this locally leads to the transition to mixed columnar‐equiaxed or even to equiaxed growth. In that case the solid‐liquid interfaces of the decanted samples show a significant depression in the centre part. In the out‐of‐centre region columnar growth still exists and the primary dendrite spacing decreases with increasing melt flow.     

烟囱桥子金矿田东西向剪切带遥感影像特征及其控矿作用研究

着重研究了吉林省烟囱桥子金矿田东西向剪切带遥感影像特征,分析了该区构造格局,并初步探讨了区内遥感影像特征及东西向构造的控矿作用,提出今后的找矿方向.     

利用DCS实现风阀电动执行器的开关量控制

简述了退火窑电动执行器的控制原理,通过分析电动执行器的故障特点,介绍了越于西门予S7-400H系统对执行器的改造方案,并重点叙述了该系统的硬件结构和控制程序的组态与设计等。     

Flatness tolerance evaluation: an approximate minimum zone solution

This paper is concerned with the problem of flatness tolerance evaluation. First, we introduce the concepts of width and inner radius of point sets, and establish the equivalence between the width of a point set and the inner radius of the convex hull of the self-difference of the set. On this basis, we present an algorithm for calculating the exact minimum zone tolerance of flatness. Second, we prove that an approximation of the inner radius of a convex set can be obtained from the inner radius of the set in fixed direction. On this basis, we present an algorithm for calculating the ‘almost exact’ minimum zone solution. This algorithm is implemented by solving a single linear programming problem, of which the computational complexity is O(n). Numerical examples are given to validate the proposed algorithms.