视觉伺服控制微机械手的细胞注射研究

细胞注射前，利用伺服控制方程计算的误差矩阵对系统进行标定，减小显微视觉系统和机械手系统间的坐标变换误差。系统误差标定后，利用显微镜聚焦—失焦技术获得深度信息，将细胞、负压管和注射针定位到同一平面上，定位误差达到0.3806μm，再结合光学流跟踪法。轨迹误差由（7，13）像素减小（0，1）像素。误差矩阵的应用非常有利于实时控制。利用纳米驱动平台设计微注射泵和负压泵，通过脉冲控制药液注射量的大小，注射泵理论注射量可以达到3．2皮升。负压泵可以安全地吸附住细胞。实验结果表明，利用上述各种技术。可以方便地完成细胞显微注射。     

注塑机注射速度的自组织模糊控制器设计

针对注塑机注射速度的非线性和时变性特点,提出了自组织模糊控制注射速度控制算法。利用控制系统输出误差和误差的变化率构造学习算法,设计了具有在线学习自组织模糊控制器。仿真结果表明:该控制器能有效跟踪理想的注射速度曲线,响应速度更快,超调量更小,控制效果优于常规PID控制器。     

转基因微注射系统中注射量的控制技术

转基因微注射系统中DNA注射量的精确控制是构建微注射自动控制系统的关键。以微流体实验为基础，构建了气压电控式微注射量控制器，以注射压力、注射时间及注射针针管半径为控制参数，实现对DNA注射量高精度、高效率而又无污染性的控制。微注射的实验结果表明，建立在上述三参数上的微注射量的数学模型是可以实现的。由此说明采用气压电控式控制方式对微注射量进行控制，确为一条方便、高效的途径。     

用于气辅注射注气控制的数字模糊PID控制器

为了改进气辅注射注气控制系统的性能，本文在传统的PID控制中引入了模糊控制，开好一种数字模糊PID控制器，该控制器特别适合于那些难以建立精确数学模型。非线性和大滞后的过程，而且控制系统能获得良好的动态特性，本文详述了模糊控制器的设计，PID控制器的设计以及结合这两种控制器优点的数字模糊PID控制器的设计。     

基于PLC控制器的煤矿卡轨车控制系统研究

卡轨车是煤矿中重要的辅助运输装备，良好的控制系统是确保设备稳定可靠运行的基础和前提。基于PLC控制器设计了卡轨车的控制系统，该系统采用冗余设计，通过两套PLC控制器进行控制，以提升系统运行的可靠性。控制器型号为S7-300，采用模块化设计，由CPU、电源、计数器、数字量输入/输出等模块构成，变频器选用的型号为D7260，属于隔爆安全型变频器。对控制系统软件总体工作流程进行了分析，对主界面进行了详细设计。控制系统的成功实践应用使设备的运行成本大幅度降低，经济效益显著。     

数字化细胞注射器的试验研究

针对目前广泛采用的细胞微注射器存在的系统结构复杂、注射量控制精度低等缺点，研制了基于叠堆式压电陶瓷微位移特性的数字化细胞微注射器，建立了数字化注射器的理论模型，进行了试验器件基本尺寸的计算。注射器注射试验结果表明，注射器注射量控制精度接近皮升级。     

基于AVR单片机的小型单螺杆空气压缩机控制器开发

针对目前小型单螺杆空压机控制器的功能需要和市场需求,基于AVR单片机技术,结合模块化柔性设计理论,开发了一款小型单螺杆空压机控制器,系统以ATmega16单片机为核心,设计了A/D采样、开关量输入、键盘扫描、开关量输出、LCD显示与报警等外围接口电路,并开发了相应的控制器系统软件.工程实际测试与应用结果表明,该控制器具...     

状态观测器与控制器的统一设计方法

状态观测器与控制器是自动化装置中比较重要、新颖的两种。状态观测器是在状态检测量不足时用于获取全部系统状态的一种硬（或软）设备，当它与控制器联合应用时，会呈现双环路系统固有的振荡倾向，本文提出一种协调优化的设计方法，可以兼顾两者的工作。     

一类切换模糊PID控制器设计及其仿真

提出了一类高动态性能切换模糊PID控制器设计方法.通过对传统PID控制中比例控制和微分控制作用的分析,结合模糊PID控制器鲁棒性能和自适应性好的优点,设计了一类新的模糊控制器.由于该类控制器先后经历比例控制,微分控制和模糊PID控制的切换,使被控系统不仅具有一般模糊PID控制器的所具有的良好的鲁棒性能和自适应性,而且与一般模糊控制器相比具有更小的超调量和调节时间,是一类动态性能良好的控制器.最后将该控制器应用于一伺服系统进行仿真对比,并给出了Simulink仿真框图.仿真结果说明了该控制器的优越性.     

微机模糊控制理论与应用

简述了模糊控制理论与应用技术的形成及发展，扼要介绍了模糊控制器的一般原理和控制器的基本设计方法，以及模糊技术在工业和家用电器方面的应用情况。     

排尘孔涡轮冷却叶片叶顶流动与传热研究

涡轮叶片叶顶排尘孔用于清除冷气中掺杂的尘粒,以保证气膜孔和冲击孔的可靠工作,但排尘孔射流引起叶顶流动和传热问题。采用参数化方法建立有、无排尘孔涡轮冷却叶片几何模型,基于包含叶片主体、主燃气通道和三腔回流式内冷却通道的全局模型,采用流热耦合数值分析,开展排尘孔对涡轮冷却叶片叶顶流动与传热问题的初步研究。研究结果表明,对比有、无排尘孔叶片,排尘孔射流可降低叶顶平均温度约25 K;冷却通道对流换热作用和叶顶排尘孔射流可使叶顶平面降温400～600 K,冷却效果与冷却通道冷气流量和尘孔结构在叶顶位置相关;排尘孔叶顶射流对叶顶间隙高温燃气泄漏具有阻碍作用,可以提高叶片总压恢复系数约0.5%～1.5%,随着冷气流量的增大,这种作用增强;尘孔结构设计应兼顾射流对叶顶流动与传热的共同影响。     

水生物种基因转移微注射自动化技术

针对目前水生物种转基因注射时存在的手工操作注射效率及成功率低等缺点,研究用于水生物种基因转移的专用细胞自动注射技术。提出卵细胞自动定位输送、吸持、注射的方法。研制了细胞自动注射试验系统,进行鱼卵细胞自动注射试验研究,试验表明,在注射过程中可完成卵细胞的自动定位输送、吸持、注射;可完成未注射和已注射卵细胞的分离和计数;可实现注射过程的计算机控制。该技术的研究为实现水生物品种杂交及品种改良提供高效快捷培育方法。     

Investigation of design parameters for droplet generators driven by piezoelectric actuators

This paper presents a numerical analysis of a drop-on-demand (DOD) piezoelectric (PZT) actuated droplet generator. A finite difference numerical model was established to analyze the design parameters of droplet ejection. First, we discussed the influence of the driving conditions on the droplet ejection characteristics, such as the driving time and the driving volume change in the pressure chamber. The volume factor, an important design parameter, was proposed from the analysis. The ejected droplets can maintain the same ejection velocity at different nozzle diameters, as long as the volume factor remains the same. Two empirical formulas, based on the analysis data, are suitable for the design of PZT actuated droplet generator. The first empirical formula is a linear relationship between the droplet velocity and the volume factor with a slope of 0.3422 for different nozzle diameters. The second empirical formula defines the driving volume of PZT and nozzle diameter to eject the desired droplets. The geometrical design parameters of droplet generator, such as the nozzle thickness, the pressure chamber width and depth, as well as the driving conditions of the PZT actuator, are all included in the analysis. The sensitivity of geometrical design parameters which affect the droplet volume, the droplet velocity, and the lowest driving condition is established. The quantitative criterion for ejection of droplet, liquid jet, and no droplet is presented. The proposed empirical formula and figures provide easy-to-use tool for design of DOD PZT actuated droplet generators.     

The effect of injection pressure and fuel viscosity on the spray characteristics of biodiesel blends injected into an atmospheric chamber

An experimental study was conducted to examine the effect of injection pressure and fuel type on the spray tip penetration length and the angle of spray injected into atmospheric chamber. The objective of the present study is to formulate empirical correlations of the spray tip penetration and the spray angle for non-evaporative condition. The experiment was performed by a common rail type high-pressure injector for the diesel engine at the injection pressure 40??100 MPa and four different fuels (D100, BD25, BD45, and BD65). The results showed that the biodiesel content increased the spray tip penetration and decreased the spray angle. The correlation of spray tip penetration is expressed for each region before and after spray break-up time in terms of injection pressure, fuel viscosity and time after start of injection. The correlation is also obtained for spray angle equation terms of injection pressure and fuel viscosity.     

Influence of water injection parameters on the performance of a water-lubricated single-screw air compressor

A thermodynamic model of a water-lubricated single-screw air compressor was established to examine the impact of water injection parameters on performance. Heat transfer and leakage between humid air and water was considered by analyzing the impacts of rotation speed, discharge pressure, the rate of water injection, and diameter of droplets on the performance of a compressor. The discharge temperature could be reduced by increasing the rate of water injection, resulting in the compression procedure moving towards an isothermal state. The increase in the rate of water injection under rated conditions from 60 L/min to 80 L/min resulted in a reduction in the compressor discharge temperature, increased the volume efficiency, and increased adiabatic efficiency by 11.1 K, 1.5 %, and 2.8 %, respectively. Water injection atomization increased the area of transfer of heat between humid air and water and improved the performance of compressor.

     

Effects of needle response on spray characteristics in high pressure injector driven by piezo actuator for common-rail injection system

The common-rail injection systems, as a new diesel injection system for passenger car, have more degrees of freedom in controlling both the injection timing and injection rate with the high pressure. In this study, a piezo-driven injector was applied to a high pressure common-rail type fuel injection system for the control capability of the high pressure injector’s needle and firstly examined the piezo-electric characteristics of a piezo-driven injector. Also in order to analyze the effect of injector’s needle response driven by different driving method on the injection, we investigated the diesel spray characteristics in a constant volume chamber pressurized by nitrogen gas for two injectors, a solenoid-driven injector and a piezo-driven injector, both equipped with the same injection nozzle with sac type and 5-injection hole. The experimental method for spray visualization was based on back-light photography technique by utilizing a high speed framing camera. The macroscopic spray propagation was geometrically measured and characterized in term of the spray tip penetration, spray cone angle and spray tip speed. For the evaluation of the needle response of the above two injectors, we indirectly estimated the needle’s behavior with an accelerometer and injection rate measurement employing Bosch’s method was conducted. The experimental results show that the spray tip penetrations of piezodriven injector were longer, on the whole, than that of the solenoid-driven injector. Besides we found that the piezo-driven injector have a higher injection flow rate by a fast needle response and it was possible to control the injection rate slope in piezo-driven injector by altering the induced current.     

鞘气聚焦电纺射流喷射的电学特性

开展了鞘气聚焦高效率纺丝射流喷射的研究。搭建了带有微弱电流检测模块的鞘气聚焦电纺喷射实验平台,讨论了鞘气约束作用下纺丝射流的流变与运动行为,结合理论模型分析了鞘气供气压强等工艺参数对纺丝电流的作用规律。实验显示:鞘气聚焦促进了射流的拉伸细化,降低了射流喷射临界启动电压,减小了纳米纤维的直径、提高了电纺纳米纤维的均匀性。当供气压强由0kPa上升到50kPa时,射流喷射平均临界启动电压由10.2kV降低至2.9kV;施加电压为4kV时,经4.4s产生峰值为532nA的冲击电流,稳定喷射阶段纺丝电流为300~500nA。鞘气聚焦还减小了射流直径和表面电荷密度,纺丝电流减小至没有鞘气聚焦时纺丝电流的1/7;纺丝电流随着鞘气压强、喷头至收集板距离的增加而降低,随着施加电压和溶液质量百分数的增加而增大。得到的结果表明:鞘气聚焦抑制了射流喷射过程的电荷干扰,减小了纺丝射流直径,提高了静电纺丝的稳定性。该方法为改善静电纺丝技术的控制水平提供了新的途径。     

压气机叶顶微喷气扩稳研究（英文）

The mechanism of compressor stall margin enhancement using the tip air injection is explored. The transonic compressor, NASA Rotor 37, is taken as the object to study the tip clearance flow under active control of tip air injection by numerical simulations. The effects of injection parameters(injection total temperature, injection position, injection angle, injection mass flow, injection port size, injection type and etc) on the stall margin extension are emphatically analyzed. Results show that the enhancement of tip leakage vortex enlarges the low-energy region induced by the shock wave in the row channel when the working condition is moving to stall point. In addition, the enhancement of radial vortex increases its entrainment ability, which tends to expand separation zone. Once the tip injection imposed, the decrease of the leakage vortex intensity widens the stall margin, while the total pressure loss increases to some extent due to the mixing of the tip micro jet with the mainstream. It is found that injection parameters should be restricted to a moderate region so as to achieve a good stall margin extension without an excessive increase in the pressure loss.     

COMPARISON OF TWO METHODS TO INCREASE TIP CLEARANCE AND ITS EFFECT ON PERFORMANCE OF TURBOCHARGER CENTRIFUGAL COMPRESSOR STAGE

Tip clearance between the blade tip and casing of a centrifugal compressor can be varied through two methods:by changing the blade height(M1)or by changing the casing diameter(M2). Numerical simulations are carried out to compare these two methods and their effect on the stage and impeller performance.The impeller and diffuser are connected through rotor stator boundary using frozen rotor approach.Overall stage performance and the flow configuration have been investigated for nine tip clearance levels from no gap to 1 mm.Impeller and diffuser performances are also pre- sented separately.It has been found that the overall and impeller performance are comparatively better for M1 below tip clearance of 0.5 mm whereas M2 is found advantageous above 0.5 mm of tip clear- ance.Both M1 and M2 show performance degradation with the increase in tip clearance.Two models have been proposed for the stage total pressure ratio and efficiency,which are found to be in agree- ment with experimental results.The impeller efficiency and the pressure ratio are found to be maxi- mum at tip clearance of 0.1 mm for both the cases however minimum diffuser effectiveness is also observed at the same clearance level.Diffuser effectiveness is found to be maximum at zero gap for both cases.As it is practically impossible to have zero gap for unshrouded impellers so it is concluded that the optimum thickness is 0.5 mm onwards for M1 and 0.5 mm for M2 in terms of diffuser effec- tiveness.Mass averaged flow parameters,entropy,blade loading diagram and relative pressure fields are presented,showing the loss production within the impeller passage with tip clearance.