6自由度绳牵引并联机构的PD反馈控制方案设计

本文对六自由度绳牵引并联机构的控制方案进行研究,建立了其Pd反馈控制规律;并对绳内力进行了线性化和解耦处理。文中综合非线性系统线性化理论以及绳牵引并联机构的线性化研究知识,应用实时测量的绳长和终端位置参数将内力矩阵化成一个线性回归矩阵和一个带有绳子和驱动器连接点参数的参数矩阵的乘积;并利用lyAPunOV原理进行了闭环系统稳定性分析,实现了一类6自由度绳牵引并联机构的闭环反馈控制

Characteristic of the Dielectric Barrier Discharge in Air at Difference Pressure

建立了一套放电装置,放电室内的空气压力可调。设计并制作了单面梳状和平行双平面两种电极板,在不同气压环境下进行空气介质阻挡放电实验。拍摄记录了放电现象,采用电荷-电压(q-V)法处理了放电的有关测量数据,对实验结果进行了分析。研究结果表明,空气介质阻挡放电的特性变化与放电环境气压有关。在各种气压条件下,该文的介质阻挡放电均呈脉冲群间歇性;随着放电环境气压减小,放电由常压下的粗大流注电晕逐渐变成细而密集的细丝状微流注电晕,直至融合为貌似辉光放电;放电脉冲群的密度和宽度也随气压降低而增加,但脉冲幅值减小。放电的有功功率随气压变化并非单调增减,当放电气压约为0.04 MPa时,消耗的有功功率最小,常压下和近真空时放电的有功功率都要大得多。A setup for DBD(Dielectric Barrier Discharge) at different air pressure was built up.Two kinds of electrode,plate-plate and a plate-strip like comb,were designed and made.The phenomenon of the DBD was shot and the data of the DBD experiment at different air pressure were recorded and analyzed.The results presented that the characteristic of the DBD in air changed related with surrounding pressure.The DBD was excited by intermittent cluster of impulses at different pressure.As the decrease of the pressure,the corona discharge of the DBD appeared from sparse column to dense filament until it developed into homogeneous glow-like discharge,and the density and the width of the impulse cluster increased,but its amplitude reduced.The power in the DBD discharge varied with the pressure non-monotonously and it reached its lowest point while the pressure was about 0.04 MPa,which was far less than that at atmosphere pressure and near vacuum.福建省自然科学基金资助项目(A0410001

Horn Antenna Gain Measurement Based on Vector Network Analyzer

利用微波暗室、矢量网络分析仪、角锥喇叭天线以及电脑等设备建立了一套喇叭天线测量系统;采用两相同天线法,分别测量了4~6 GHz、6~8 GHz角锥喇叭天线的增益值,对测量数据进行误差分析和近距修正;并将增益的实测值与理论计算值进行对比.实验结果表明,近距修正后,所测量的4~6 GHz与6~8 GHz频段天线的增益实测值与理论值的最大偏差值分别为-0.20 dB和-0.19 dB,均在±0.25 dB范围内,符合标准增益天线增益的精度要求,也与天线出厂的指标相符,表明所建立的测量系统对于喇叭天线增益的测量有效可行.中航工业创新基金产学研项目(cxy2013XD28

零质量射流技术的新发展及其在流动控制中的应用

零质量射流是主动流动控制的新技术。与常规射流相比,零质量射流最突出的优点在于具有零净质量流量。在应用零质量射流进行流动控制时,不再需要常规射流中必不可少的流体输送管道与其他机械部件。新型等离子射流较传统零质量射流可以获得高能/高动量零质量射流,可应用于宏观大尺度上的主动流动控制。文中阐述传统零质量射流和新型等离子射流的产生机制,概括和分析零质量射流在主动流动控制上的应用。福建省自然科学基金项目(A1010014

风洞试验绳牵引并联支撑技术研究进展

新型飞行器的研制越发强调先进的飞行性能,这对风洞试验模型支撑技术提出了高的要求,为扩展风洞试验的能力,迫切需要研究新型的智能支撑技术。绳牵引并联支撑是基于机器人技术的一种新型机构,具有刚度较大,动态性能良好等优点,为风洞试验提供了一种新的手段。首先,全面论述了绳系支撑在风洞试验中的应用,并给出动态分析;进一步根据绳牵引并联支撑技术的特点,将其分为可实现受迫运动的冗余约束支撑,以及可实现受迫+自由运动的欠约束支撑;其次,重点阐述了冗余约束与欠约束两类支撑系统的若干关键技术问题及其研究进展;最后,指出绳牵引并联支撑技术的发展方向是具有可重构性和智能化。可为绳牵引并联支撑技术在风洞试验中的工程应用提供一定的理论指导与技术支持。国家自然科学基金(11472234,11702232,11072207,50475099);;中央高校基本科研业务费专项资金(20720180071)~

Radiation characteristic measurement of low temperature plasma under atmospheric pressure

本文在自行设计的放电电极板上实现常压下的空气辉光放电(APGD),产生出一薄层的低温等离子体,利用光栅单色仪及测试声强和温度的仪器对所产生的等离子体的光辐射、声辐射和热辐射特性进行实验测量。数据处理后的分析结果表明,该APGD等离子体的光辐射强度及声辐射和热辐射强度,以及总辐射能量基本上都与电极板的加载功率呈线性关系,而且各种形式的能量各占比例是一定的。研究结果表明可以通过沿面APGD的辐射特性与加载功率之间的关系来描述APGD等离子体的特性,以及控制等离子体的产生量。A thin layer of the low temperature plasma due to Atmospheric Pressure Glow Discharge (APGD) in air was produced on the planar surface of designed electrode plates. The optical, acoustic and thermal radiation characteristics of the produced plasma were measured in experiment with a grating spectrograph system, a sound level meter and a non-contact thermometer, respectively. The analysis results from the data processed indicate that the intensity of the optical, acoustical and thermal radiation of the APGD plasma grow linearly up with the increasing power applied to the electrode plate, which demonstrates that the total radiance varies linearly with the power and that every kind of radiant energy has a proper proportion. The study shows that it is feasible to describe the behavior of the APGD plasma and to control it quantitatively by the obtained relationship between its radiation characteristic and applied power.福建省自然科学基金(A0410001

Calibrating Testing and Data Processing of MEMS Rate Gyro

分析了以微电子机械MEMS技术制成的单片偏航角速率陀螺仪ADXRS150的匹配电路原理与工作原理,阐述了角速率陀螺仪的设计要点,设计并搭建了其标定实验平台,对其进行标定实验,通过对标定实验所得的数据进行处理和分析,得到标定曲线和误差分析关系式,从而给出在陀螺仪标定实验可行的数据处理方法。The matching circuit and the principle of the single chip rate gyro,ADXRS150,based on integrated micro electro-mechanical system have been introduced and analyzed.The keystone in design of the rate gyro was explained.The rotational stand for the test to the gyro was built and the calibrating has been carried out.The experimental data recorded by compute has been processed through analyzing.The relationship between the angular rateω and the output voltage V of the gyro is obtained.The error analysis for calibrating test data is presented.The result shows the method of the calibrating test and the data processing on the gyro is available.国家自然科学基金项目(50475099

Experiment on flow field and thrust induced by plasma actuators

为了深入了解等离子体激励器流动控制原理,采用PIV技术获得了静止空气中的等离子体激励器上表面诱导气流及其末端引射气流流场的流速分布和流态,并对由此产生的诱导推力进行了测量实验;研究了等离子体激励器上表面诱导气流加速机理和尾部流场形态以及电极对数对诱导气流加速的影响,并与推力实验结果进行比较。研究结果表明,等离子体激励器上表面空气被诱导产生定向流动,并在多对平行电极的作用下被逐渐加速;诱导气流在激励器末端的引射作用形成射流,增加等离子体激励器电极对数可以增大该射流的流速;所产生的诱导推力也随诱导气流流速的加速相应增大。The velocity distribution and flow pattern of the induced flow on the surface and in the downstream of the plasma actuator were obtained by PIV technique in the still air and the induced thrust produced by the flow also was measured with an electronic balance.The mechanism of the induced flow on the actuator surface was investigated.The effect on accelerating the induced flow by the electrode number was compared with the induced thrust measured.The results show that the air flow induced on the plasma actuator is directional to form a jet in the downstream edge of the actuator and the flow is gradually accelerated by the electrodes parallel in both side of the actuator.Both the jet velocity and the induced thrust increase with adding electrode number.福建省自然科学基金(2010J01014

INTERVAL INCLUSION COMPUTATION FOR THE SOLUTIONS OF THE BURGERS EQUATION

National Natural Science Foundation of China [10571146]In this paper we study the interval computation for the solutions of the Burgers equation. For the initial-boundary value problems of the Burgers equation by using the technique of the Green function, a new kind of interval method is proposed. Both algorithm and computational examples are given. Convergence is proved. From the results we see that this interval method can get a better solution with our corroboration

System simulation of vertical 3-DOF cord-drawn parallel mechanism

给出所设计的立面一个转动两个平动(1R2T)三自由度绳牵引并联机构的模型.针对此机构模型,建立了运动学逆解模型;接着提出两种计算绳拉力的算法,并具体分析了其中一种算法.以末端执行器实现椭圆型的运动轨迹为目标,进行轨迹规划,研究绳的运动特性.采用Simlink仿真软件对该系统进行了一系列的仿真,包括:绳长变化、绳的速度、加速度变化以及绳的拉力变化.仿真结果表明:在所规划椭圆轨迹下,所有绳速度、加速度的变化是连续的;一些绳拉力的变化比较大,另一些绳拉力的变化比较小.提出的运动轨迹规划方法,具有通用性.A model of the vertical 1R2T 3-DOF cord-drawn parallel mechanism is presented in this study.Afterwards,a reverse kinematical model is established.The cord tension is subsequently obtained via two different calculations,one of which is analyzed in details.Accordingly,a generic track planning is conducted based on the motion tracking of end manipulator.Consequently,the cord motion characteristics,including variations of cord length,velocity,acceleration and tension,are simulated using Simulink TM.It is indicted that the variation of cord velocity and acceleration is consecutive,whereas the variation of cord tension is not tendentious.国家自然科学基金资助项目(50475099