针铁矿法沉铁过程亚铁离子浓度预测

针对针铁矿法沉铁过程出口亚铁离子浓度离线化验获得,存在很大滞后性,难以实现沉铁过程实时控制的问题,研究反应器出口亚铁离子浓度在线预测方法.本文在分析沉铁过程化学反应机理的基础上,考虑铜离子对反应过程的影响,结合连续搅拌反应器（Continuous stirred tank reactor,CSTR）特性,建立了针铁矿法沉铁过程的机理模型,并提出了基于信息交换的双粒子群搜索算法（Double particle swarm optimization,DPSO）优化选择机理模型的参数,构建基于最小二乘支持向量机（Least squares support vector machine,LS-SVM）的机理模型输出误差的补偿模型,采用并联补集成方式建立了亚铁离子浓度的集成预测模型.工业现场数据验证了所建模型能有效地反映亚铁离子浓度的变化趋势,为针铁矿法沉铁过程的优化控制奠定了基础.     

Delay time compensation based on coefficient of restitution for collision hybrid motion simulator

A hybrid motion simulator embeds a hardware experiment in a numerical simulation loop. However, it is often subjected to the inherent problem of an energy increase in the collision of two pieces of hardware in a loop because of the delay time. This paper proposes a delay time compensation method based on contact dynamics model for a collision hybrid motion simulator under delay time and establishes a compensation method for coupled translational and rotational motion. The model developed in this paper describes linear uniform motion of a floating object during the period of the delay time until the force and torque are observed and non-linear motion according to environmental stiffness after the initial delay time period in contact. By using the above model, compensation parameters are designed based on desired coefficient of restitution with iterative calculation. The proposed method achieves accurate delay time compensation and simultaneously realizes a variable desired coefficient of restitution over a wide range of frequencies. Furthermore, the compensation method for multi-dimensional motion is established under the assumption that the friction effect is very small. The efficiency of the proposed method is verified through collision experiments for the coupled motion in two dimensions.     

Dynamic compensation by fusing a high-speed actuator and high-speed visual feedback with its application to fast peg-and-hole alignment

This paper presents a dynamic compensation concept to grapple with the dynamic defects of a traditional robot arm, especially while performing high-speed endpoint regulations. The proposed high-speed dynamic compensation concept offers a new point of view for cooperating with a traditional manipulator to realize highly dexterous performance of manipulations. The concept is realized through adoption of a high-speed light-weight actuator as well as endpoint closed loop configured high-speed cameras. The dynamic compensation is analyzed experimentally with 1000 Hz visual feedback and a high-speed finger for a robot arm in the case of one degree of freedom. The advantage of the proposed approach is that the modeling for the robot system’s dynamics is not needed, whereas it is necessary and trivial in order to realize high-speed regulations by traditional approaches. Thus, the control issue becomes easier with the proposed approach. As an application for this concept, fast peg-and-hole alignment with large position and attitude uncertainty is studied. The alignment algorithm is based on a visual compliance strategy. Alignment experiments show that with the proposed concept of dynamic compensation as well as visual compliant motion control, robust and fast convergence was realized for most cases.     

面向ZigBee的视频多描述编码及其传输性能仿真

针对视频码流在ZigBee等不可靠低速无线网络传输时易发生编码信息包丢失而导致接收端无法正确解码这一问题,提出一种基于3D-SPIHT视频多描述编码方案。与传统多描述编码如MDSQ相比,该方案创建的各描述质量平衡,并能通过去除视频帧间冗余来提高压缩比;与国际标准（H.264等）相比,该方案具有算法简单、能够在任意码流截断处解码、码率可连续分级和无明显块效应等优点。实验表明,该编码方案能够较好地应用于ZigBee多信道网络,并在较大压缩比的情况下仍能获取质量较好的重建图像,具有较高的应用价值。     

基于Kalman滤波的谐波电流实时检测仿真分析

谐波电流的实时检测是有源电力滤波器实现的关键,数字化的实现引入了一定的时间延迟,影响了其滤波效果。将三相谐波电流进行Clark坐标变换到两相正交坐标系中,利用Kalman算法对系统进行建模,检测出各次谐波电流的幅值和相角。通过选取合理的Kalman状态变量,运用简单的代数运算向模型中增加了一个相位补偿角,来消除延时的影响。最后,利用Matlab进行仿真实验,验证了该方法的有效性和正确性。     

硅压阻式气压高度计的设计与实现

采用硅压阻式压力传感器,以ATmega88PA为控制器设计了气压高度计。内嵌全温度范围的曲面拟合算法进行温度补偿及线性化处理,解决了压力传感器的温漂和非线性问题,并用海拔高度与气压的关系计算高度。测量结果通过RS-485接口发送给上位机。测试结果表明,该气压高度计压力测量误差优于0.50‰,分辨率为0.01 h Pa,线性度为0.999 9;标准大气环境下高度测量误差为0.16 m,线性度为0.999 8。该气压高度计具有质量小、功耗低、精度高、工作可靠等优点。     

主从式测量系统中传感器标定方案的研究及实现

针对主从式测量系统中传感器的标定问题,提出从上位机软件进行标定的方案,着重分析软件标定的数据采集及处理过程,并根据标定直线及标定常数的数值判定是否需要进行原点补偿。实验证明,从上位机软件角度对传感器进行标定更加简单方便,并且降低了对生产线标定人员的专业知识要求,该方法适合应用于工业现场对传感器进行标定,有较高的实际应用价值。     

基于F2812高精度抗震动电子天平系统设计

采用F2812作为主控制器,对高精度、低成本、抗震动的电子天平系统进行设计。利用F2812高速运算能力,对AD转换后的称重数据进行数字滤波,通过程序判断有无加卸载称重样品,对滑动平均滤波算法进行改进,不仅提高了电子天平的称重精度,又加快了称重速度。为使其能在地表震动、温度变化频繁等恶劣环境中稳定工作,对电子天平增加了震动和温度补偿,改善了称重系统的动态稳定性。基于VC++开发了电子天平上位机监控软件,方便工作人员在主控室中对电子天平实时称重信息进行监测、补偿模式进行远程控制和查询历史数据。     

含温度补偿的便携式土壤水分测定仪研制

针对现有土壤水分测定仪的不足,研制了一种新型的便携式土壤水分测定仪。传感器快速测量出土壤温、湿度数据,GPS自动获取时间、经纬度信息,数据既可临时保存在仪器的存储芯片中,又可通过GPRS/GSM将数据及时发送到后台数据库和手机用户。通过温度补偿和野外验证实验得出,温度补偿项为Δy=0.0002 t3-0.011 t2+0.444 1 t-6.423 2,仪器所有功能运行正常,测量绝对误差为-3.64%~3.82%,平均绝对误差为2.24%,精度较高,适合在地方农技和水利部门推广应用,有助于农业水利信息化水平的提高。     

Novel one-step formed composite reinforcement of "Spider web like" SiCnw networks and "Z-pins like" SiC rods for ablation resistance improvement of C/C-ZrC-SiC

A novel composite reinforcement with horizontal multilayer "Spider web like" SiC nanowire networks and vertical interconnected "Z-pins like" SiC rods was designed and prepared by facile one-step figuration. The linear ablation rate of "Spider web like" SiC nanowire networks and "Z-pins like" SiC rods collectively reinforced C/C-ZrC-SiC composites at 2610 ± 20 ℃ was 0.4 ± 0.03 μm/s with a 74.19 % reduction. The improved ablation resistance was attributed to a denser gradient oxide layer composed of central ZrO₂ layer, transitional ZrO₂-SiO₂ layer and marginal SiO₂ layer generated under the initial sticky net effect from SiCnw networks and subsequent oxide compensation from "Z-pins like" SiC rods.