Composite Finite‐time Convergent Guidance Law for Maneuvering Targets with Second‐order Autopilot Lag

This paper aims to develop a new finite‐time convergent guidance law for intercepting maneuvering targets accounting for second‐order autopilot lag. The guidance law is applied to guarantee that the line of sight (LOS) angular rate converges to zero in finite time and results in a direct interception. The effect of autopilot dynamics can be compensated based on the finite‐time backstepping control method. The time derivative of the virtual input is avoided, taking advantage of integral‐type Lyapunov functions. A finite‐time disturbance observer (FTDOB) is used to estimate the lumped uncertainties and high‐order derivatives to improve the robustness and accuracy of the guidance system. Finite‐time stability for the closed‐loop guidance system is analyzed using the Lyapunov function. Simulation results and comparisons are presented to illustrate the effectiveness of the guidance strategy.     

基于FPGA的白光干涉仪数据采集系统的设计

为了对白光干涉仪的干涉条纹进行分析处理,该文设计了一种以FPGA为核心的数据采集系统。低相干白光光源在发生干涉后,会形成明暗相间的干涉条纹。通过对干涉条纹测量分析,就能对数据进行精确的测量。整个系统以FPGA作为主控制器,配以CCD采样,AD模数转换,内部FIFO存储、以太网高速传输,从而把干涉数据实时传送到上位机中,具有传输速度快,效率高等优点,实现了白光干涉信号的数字化处理。     

一种事件序列相似性评估方法

事件序列广泛出现在工业制造和信息科学的各个领域,如流水线中的操作流、字符串、用户访问网站的点击流、DNA序列、系统维护记录等。不同于数字信号处理中的时间序列,事件序列的自变量是代表顺序的有限正整数,因变量是表征事件的常量,这样的常量没有大小之分,是定性的特征。文章立足于实际应用,通过把问题转化为一个线性规划问题,建立了一种局部特征适应性好的相似性评估方法,并成功应用于某型导弹武器系统的考核评估中。     

基于FPGA的虚拟现实定位系统设计

虚拟现实技术是目前计算机信息科学中的前沿学科,文中设计了一种以FPGA为核心的数据采集处理系统。利用HMC5883L和ADXL345对虚拟场景中物体的方位和朝向进行确定并通过以太网给虚拟场景主机发送数据。整个系统以FPGA作为主控制器,配以传感器数据采集,内部FIFO存储,以太网高速传输,从而把定位系统参数实时传送到上位机中,具有传输速度快、实时性等优点,实现了虚拟现实高精度定位的功能。     

SiC器件对并网逆变器EMC特性和效率的影响

近年来,宽禁带器件SiC MOSFET在并网逆变器邻域已经取得了越来越多的关注。首先,讨论了SiCMOSFET三相并网逆变器EMC模型的建立,并通过分析噪声源的模型进行等效替代,结合逆变器损耗对于噪声传导路径的阻尼作用,得到了SiC逆变器的EMC仿真模型和理论模型;然后,通过逆变器平台实验的结果与仿真模型和理论模型的结果进行了对比,验证了模型的可行性;最后,通过实验比较了沟道栅SiC逆变器、平面栅SiC逆变器和Si IGBT逆变器3者在相同开关频率下的传导干扰和不同开关频率下的满载效率。     

固相微萃取(SPME)技术与质谱技术联用研究进展

SPME是二十世纪八十年代末期发展起来的一项革命性的样品前处理技术。经过十余年的发展演变，目前已经成功地实现了与各现代分析仪器的联用并应用于诸多研究领域。本文综述了固相微萃取（SPME）技术研究进展，主要包括SPME发展现状及技术特点，讨论了SPME在萃取纤维涂层，材料，键合技术，复合/交联键合相等方面的改进；同时综述了该技术与现代分析仪器联用方面的应用进展。     

税控燃油加油机计量比对方法及不确定度评定

文章从笔者参加的税控燃油加油机计量比对工作出发,针对比对过程中的一些方式方法和注意事项进行分析整理,并对比对不确定的评定做出说明。     

歧口17-2油田总体开发方案的优化

歧口17-2油田是一个边际油田，用渤海以往的开发模式不能经济有效地投入开发。在“三新三化”原则的指导下，通过对该油田的开发方案进行多次优化，终于在技术可行、安全可靠的前提下，把盈利率水平提高到规定的目标以上，完成了总体开发方案的编制，为该油田的开发，打下了坚实的基础。     

Design,development, and field evaluation of a rubber tapping robot

Modern robotics has made great strides in the field of agricultural harvesting. In the field of rubber tapping, however, there are still significant challenges to be faced. As one of the few agricultural harvesting areas primarily manual, rubber tapping requires precise control of the knife in the forest's unstructured environment at night. This paper presents the design of a rubber cutting robot for natural rubber plantations. An upgraded spatial spiral trajectory is established by analyzing the trunk and manual rubber cutting trajectories for the operation of a six-axis tandem robot arm. A compact binocular stereo vision system achieved the initial perception of the parameters required for the cutting trajectory. Besides, an integrated end-effector was developed to enable further precise perception of the cutting trajectory and cutting operations. The system was tested in the field at a rubber plantation in Hainan Province. The upgraded trajectory's adaptability and the accuracy and efficiency of the starting point positioning algorithm were verified. The operational performance of the complete system was evaluated to help guide future improvements. The error of the start point locating is 1.0 $\pm$ 0.1 mm, and the execution time is 17.01 $\pm$ 3.65 s. The bark consumption—cutting depth setting of (2.0 and 5.0 mm) is more appropriate for the rubber tapping robot. Then the accuracy of chip thickness and chip width is about 1.73 $\pm$ 0.28 mm, and 5.07 $\pm$ 0.13 mm, respectively. Furthermore, the accuracy of chip weight is 1.99 $\pm$ 0.24 mm. The average operating time of the whole tapping operation is 80 $\pm$ 5 s. Future work will include improvements in system stiffness and robustness. This study demonstrates the potential of applying industrial robotics to the field of latex harvesting. Robotics may be a future development towards mechanized rubber tapping.     

智能变电站通信网络虚拟局域网建模与优化配置方法

目前虚拟局域网(VLAN)的配置主要由人工完成,工作量大,且缺乏统一的标准和评价指标,容易出现人为错误,给保护控制系统的可靠性带来隐患。分析了VLAN优化配置的约束条件,并基于智能变电站通信网络拓扑结构和设备间报文订阅关系等建立了VLAN配置的通信网络模型。结合VLAN模型,提出了报文最短路径的计算算法,进而实现了VLAN的自动配置与优化。以某实际智能变电站的VLAN优化配置为例,将所提优化方法与现有优化方法进行对比分析,结果证明了所提方案的有效性和实用性。