多控制点高速砖式灌装机控制系统的设计

高速无菌砖式饮料灌装机结构复杂,控制点多,既有对温度、压力、液位、流量等的过程控制,又有对包装机械速度和位移的运动控制,而且整个生产过程必须处于严密的监控之下。同时,该系统还有稳定性以及高速性的要求。针对这些特点,确定了上下位机的控制模式,并设计了以PLC为控制核心、附带两个独立控制模块的控制系统。结果表明:该控制系统实现了高速运转过程中实时的、高精度的控制,且方便工人操作以及监控系统运行状态。研究成果为多点控制的机电设备控制系统设计提供了参考。

长水平段水平井靶区多控制点轨道优化设计方法

试算法设计的多控制点水平井轨道造斜段多、轨迹控制作业难度大,不利于快速钻井。结合水平井"PDC钻头+弯外壳螺杆钻具"复合钻快速钻井特点,提出了长水平段水平井靶区多控制点轨道优化设计方法,即先用直线间隔连接控制点得到控制单元,再通过选择适当曲线连接相邻控制单元形成二维或三维控制单元体。实例计算结果表明,本文提出的优化设计方法设计的靶区多控制点水平井轨道稳斜段总进尺长,三维水平井轨道可在装置角保持不变的情况完成轨迹控制作业,有利于复合钻快速钻井和提高作业效率。

基于衣片网格局部变形的服装多样性研究

针对服装建模过程中,需要反复修改衣片来获得令人满意的虚拟服装模型以及计算复杂度高的问题,提出一种基于多控制点的衣片网格局部变形方法。该方法首先建立衣片网格模型,然后利用Open GL的选择模式移动服装关键点,进而得到边界控制点,利用控制点对衣片网格模型进行局部变形,最后对衣片建立受力模型,通过虚拟缝合、碰撞检测以及纹理映射建立三维服装模型,展现服装整体效果,得到多样的服装模型。实验结果表明,由于在算法中不需要重新网络化,故具有较低的计算代价,同时也使得到的服装模型更加多样化。

Analysis and Taxonomy of Congestion Control Mechanisms for Internet Reliable Multicast

The research of congestion control for Internet reliable multicast is one of the most active fields in reliable multicast protocol research. Many reliable multicast congestion control mechanisms have been put forward. In this paper we present principal problems of congestion control for Internet reliable multicast, analyze solutions and difficulties of solving these problems, and then give a classification of some reliable multicast congestion control mechanisms. Lastly the future work is proposed.

Recent developments on applications of sequential loop closing and diagonal dominance control schemes to industrial multivariable system

With a focus on an industrial multivariable system, two subsystems including the flow and the level outputs are analysed and controlled, which have applicability in both real and academic environments. In such a case, at first, each subsystem is distinctively represented by its model, since the outcomes point out that the chosen models have the same behavior as corresponding ones. Then, the industrial multivariable system and its presentation are achieved in line with the integration of these subsystems, since the interaction between them can not actually be ignored. To analyze the interaction presented, the Gershgorin bands need to be acquired, where the results are used to modify the system parameters to appropriate values. Subsequently, in the view of modeling results, the control concept in two different techniques including sequential loop closing control(SLCC) scheme and diagonal dominance control(DDC) schemes is proposed to implement on the system through the Profibus network, as long as the OPC(OLE for process control) server is utilized to communicate between the control schemes presented and the multivariable system. The real test scenarios are carried out and the corresponding outcomes in their present forms are acquired. In the same way, the proposed control schemes results are compared with each other, where the real consequences verify the validity of them in the field of the presented industrial multivariable system control.

GRADIENT OF REFERENCE DIFFERENCE BASED MATCHING ALGORITHM FOR IMAGE FEATURE POINT

During matching on feature point, gray correlation matching technology is utilized to extract multi-peaks as a coarse matching set. A pair of given corresponding reference points within the left and right images is used to calculate gradients of reference difference between the reference points and each feature point within the multi-peaks set. The unique correspondence is determined by criterion of minimal gradients of reference difference. The obtained correspondence is taken as a new pair of reference points to update the reference points continuously until all feature points in the left (or right) image being matched with the right (or left) image. The gradients of reference difference can be calculated easily by means of pre-setting a pair of obvious feature points in the left and right images as a pair of corresponding reference points. Besides, the efficiency of matching can be improved greatly by taking the obtained matching point as a new pair of reference points, and by updating the reference point continuously. It is proved that the proposed algorithm is valid and reliable by 3D reconstruction on two pairs of actual natural images with abundant and weak texture, respectively.

Design and implementation of ethernet passive electronic network over coax

To increase the limit of ethernet over coax （EoC） technology in the bidirectional reform of the hybrid fiber coaxial （HFC） network, an ethernet passive electronic network （EPEN） system based on Coax is proposed and experimentally demonstrated in this paper. The proposed EPEN exploits the existing capabilities of the MAC layer in the ethernet passive optical network （EPON） for reduction of cost of the HFC network. As the MPCP （multi-point control protocol） is introduced in the EPEN, bandwidth control and higher efficiency can be achieved. The experimental results exhibit the throughput of system up to 100Mbps, which meet the requirements of HFC network. To improve the performance of EPEN, frequency division multiplexing （FDM） can be used for further increase of the throughput and more hardware processing modules in the future. can be implemented to enhance the capacity

结冰区流场特征一致的混合缩比翼型设计

提出了一种基于翼型前缘范围流场相似的多控制点混合缩比翼型优化设计方法:以前缘局部范围内的空间流场特征相同为目标,采用多目标遗传优化算法结合翼型参数化、多控制点、网格自适应技术及CFD,进行了不同工况下的混合缩比翼型设计,分别通过低湍流度风洞及结冰风洞对翼型的气动性能及积冰过程进行了实验。设计及实验结果表明:该混合缩比翼型与对应的全尺寸翼型在前缘15%弦长范围内的压力系数偏差均在5%以内,翼型绕流相似;在相同时间历程内两者的冰型增长及气动特性均具有相同的变化规律。该设计方法可以应用于不同实验状态下的混合缩比翼型的设计,提高多状态下结冰实验效率。