The research of adaptive sliding mode controller for motor servo system using fuzzy upper bound on disturbances

Considering sliding mode control (SMC) method using the estimation of upper bound on disturbances in motor servo system, if the upper bound is underestimated, the position tracking precision is poor. Contrarily, the control input is overlarge and even chatters violently. To solve the above problems, an adaptive sliding mode controller (ASMC) is proposed. It utilizes a fuzzy decision maker (FDM), which exports the estimation of upper bound on disturbances according to the information of position tracking error and control input. The computer simulations on a dc motor present that the proposed method guarantees satisfactory position tracking accuracy and the chattering at control input is evidently suppressed. Moreover, the output of FDM is sensitive to the changes of disturbances realtimely and precisely. Subsequently, the proposed scheme possesses strong robust performance against disturbances in motor servo system.     

A simple and cost-effective method for fabrication of integrated electronic-microfluidic devices using a laser-patterned PDMS layer

We report a simple and cost-effective method for fabricating integrated electronic-microfluidic devices with multilayer configurations. A CO₂ laser plotter was employed to directly write patterns on a transferred polydimethylsiloxane (PDMS) layer, which served as both a bonding and a working layer. The integration of electronics in microfluidic devices was achieved by an alignment bonding of top and bottom electrode-patterned substrates fabricated with conventional lithography, sputtering and lift-off techniques. Processes of the developed fabrication method were illustrated. Major issues associated with this method as PDMS surface treatment and characterization, thickness-control of the transferred PDMS layer, and laser parameters optimization were discussed, along with the examination and testing of bonding with two representative materials (glass and silicon). The capability of this method was further demonstrated by fabricating a microfluidic chip with sputter-coated electrodes on the top and bottom substrates. The device functioning as a microparticle focusing and trapping chip was experimentally verified. It is confirmed that the proposed method has many advantages, including simple and fast fabrication process, low cost, easy integration of electronics, strong bonding strength, chemical and biological compatibility, etc.     

A fuzzy cerebellar model articulation controller based visual servo system for robot

This paper presents a novel online learning visual servo controller integrating the FCMAC with proportion controller for the control of position of manipulator end-effector. Since the FCMAC has good learning capability and fast learning speed, and can save much computer memory space by fuzzy processing of input space division and memory unit activation, it is used to develop an adaptive control law by learning the relationship between the image feature errors and manipulator input, and the aim of online learning of the FCMAC is to minimize the output of proportion controller. Furthermore, the FCMAC has no need for models of robot manipulator and image feature extraction, so that the capability of proposed controller for tasks under uncertain environment can be improved. Finally, the proposed controller is proved to be effective by the experiment, and compared with BP neural network.     

150t/h循环流化床锅炉燃烧系统的建模

通过调研某发电厂循环流化床锅炉,利用从该电厂获得的历史数据以及现有的数学模型,采用MATLAB工具箱建立了传递函数模型,在此模型基础上通过仿真研究循环流化床锅炉燃烧系统的动态特性.主要研究给煤量、一次风、二次风等输入量与床温、主蒸汽压力、主蒸汽温度、炉膛出口烟气含氧量等输出量之间的关系,给出了可用于控制系统设计的燃烧系统的传递函数阵.仿真结果表明,所建立的模型能准确地反映系统的动态性能.同时分析了影响动态特性的因素,为循环流化床锅炉燃烧系统的控制策略研究建立了平台.     

Translational motion compensation for coronary angiogram sequences

A method of compensating for the lag of the video cameras typically used in angiographic systems is presented for use in sequences of digitized X-ray images. The lag effect is reduced by a straightforward weighted subtraction, which has the undesirable side effect of increasing noise. By superimposing several lag-corrected and appropriately shifted images, however, the signal-to-noise ratio can be restored. The algorithm uses the phase-correlation method to measure the two-dimensional shift of a mobile coronary arterial structure. Processing is confined to a rectangular area of interest (AOI), which encloses a feature of clinical significance. The differences of the phases of the Fourier transforms of two frames is computed, combined with an appropriate filter, and inverse Fourier-transformed to produce a phase-correlation image. The vector separation from the origin of image space of the peak of the phase-correlation image is the estimate of the shift of the artery's position in the second frame as compared to the first. The isolation of the AOI from the surrounding image is achieved by the application of a window and correction for any linear trend in the background intensity.     

经食道心房调搏的放射性核素心血管造影

本文应用反符合电路剔除调搏脉冲干扰的方法,制成经食道心房调搏心电心音门电路触发装置,用于经食道心房调搏的核素心血管造影。参考Tzivoni标准,当逐级增加调搏心率至140次/min或亚极量心率后发现:冠心病人有调搏后EF降低;急性心肌梗塞病人EF减低更为明显,并呈室壁反向运动。因此,心房调搏核素心血管造影有助于冠心病,特别是心肌梗塞的诊断。     

一种简便的饮用水除铀方法及其机理

本文介绍一种利用原水中含有的无机盐,加入廉价的化学试剂除去饮用水中微量铀的简便方法。并对其除铀机理进行了探讨,证明除铀主要是以软化水过程中产生的氢氧化镁表面吸附共沉淀机理进行的。     

单晶硅化物及其应用

本文评述了单晶CoSi_2和NiSi_2的结构特点、各种制备方法、器件应用和发展前景。采用分子束外延(MBE)和“内延”法(Mesotaxy)制备的单晶硅化物质量,电学性能和热稳定性较好。由于首次得到理想的突变的金属——半导体接触,使对金属——半导体接触的理论分析成为可能。硅/单晶硅化物/硅结构在实际应用中非常重要,如单晶硅化物作集电极埋层,能降低集电极串联电阻,克服重掺杂埋层的横扩和自掺杂问题,提高了电路工作速度,减小了器件面积。埋层硅化物也可作为微波传输线的地线,是实现高频集成电路互连的好方法。而采用该结构制备的高速器件——金属基区晶体管(MBT)和穿透基区晶体管(PBT),具有很好的应用前景。     

FD—140型高灵敏测氡仪及其应用

FD—140型高灵敏测氡仪用于测量氡的浓度,测氡灵敏度可达15mBq/m~3 min。该仪器可用于普查与勘探铀矿床,也可用于找石油、煤、金、地下水和地震预报以及地质构造调查等方面。