Optimal measurement configurations for kinematic calibration of six-DOF serial robot

An optimal measurement pose number searching method was designed to improve the pose selection method. Several optimal robot measurement configurations were added to an initial pre-selected optimal configuration set to establish a new configuration set for robot calibration one by one. The root mean squares (RMS) of the errors of each end-effector poses after being calibrated by these configuration sets were calculated. The optimal number of the configuration set corresponding to the least RMS of pose error was then obtained. Calibration based on those poses selected by this algorithm can get higher end-effector accuracy, meanwhile consumes less time. An optimal pose set including optimal 25 measurement configurations is found during the simulation. Tracking errors after calibration by using these poses are 1.54, 1.61 and 0.86 mm, and better than those before calibration which are 7.79, 7.62 and 8.29 mm, even better than those calibrated by the random method which are 2.22, 2.35 and 1.69 mm in directions X, Y and Z, respectively.     

基于微分进化遗传算法的双目摄像机标定

为提高遗传算法全局寻优的性能,将标准遗传算法改进并运用到摄像机标定,提出一种新的双目摄像机标定方法。通过改进编码方法,自适应调整变量搜索区间;引入微分进化进行交叉和变异,使群体呈多元化发展。该方法与现有的非线性标定方法相比,标定精度更高,可有效解决传统优化方法难以解决的多参数、非线性的复杂函数优化问题。实验结果表明,该方法具有较强的泛化能力,鲁棒性好。     

Design of small-area multi-bit antifuse-type 1 kbit OTP memory

A multi-bit antifuse-type one-time programmable (OTP) memory is designed, which has a smaller area and a shorter programming time compared with the conventional single-bit antifuse-type OTP memory. While the conventional antifuse-type OTP memory can store a bit per cell, a proposed OTP memory can store two consecutive bits per cell through a data compression technique. The 1 kbit OTP memory designed with Magnachip 0.18 μm CMOS (complementary metal-oxide semiconductor) process is 34% smaller than the conventional single-bit antifuse-type OTP memory since the sizes of cell array and row decoder are reduced. And the programming time of the proposed OTP memory is nearly 50% smaller than that of the conventional counterpart since two consecutive bytes can be compressed and programmed into eight OTP cells at once. The layout area is 214 μm × 327 μm, and the read current is simulated to be 30.4 μA. Foundation item: Project supported by the 2nd Stage of Brain Korea; Project supported by the Korea Research Foundation     

基于图像反馈的标靶面与光轴垂直调节系统

介绍了摄像机标定的内部参数,阐述了标靶面与光轴垂直可以简化标定的过程.当标靶面与光轴垂直时,利用标靶面上特征圆在CCD成像面上成像也是圆的特点,提出了基于图像反馈的标靶面与光轴垂直的调节方法.一般情况下,标靶面与光轴不垂直,标靶面上特征圆在CCD成像面上成像为椭圆.通过图像处理和最小二乘椭圆拟合法计算出成像椭圆的长短轴及偏角,设计了调整控制策略.实验结果表明,该方法是有效可行的.     

基于动态优先级的实时Java垃圾回收策略

针对通用平台下Java虚拟机垃圾回收器（GC）的不定期启动问题,提出了一个周期性提升GC优先级、提前调度GC的解决方案.该方案把优先级按任务的重要程度分两个等级：关键线程和非关键线程,通过计算垃圾回收的时机即计算出垃圾回收的周期上限T_GC,在任务运行最长不超过T_GC的时间内提升GC的优先级为非关键线程的最大值,从而使GC在不影响关键线程的情况下能提前回收内存中的垃圾,使虚拟机的内存处于非饱和状态.理论分析和实验结果表明,该方法可以提高通用环境下Java关键线程的实时性及执行的可预测性.     

地震层位标定方法综述及应用

在岩性油气藏的勘探过程中,地震层位标定是地震资料构造解释和地震储层研究的基础.介绍了基于合成记录层位标定和VSP层位标定的原理,并指出两者在单一标定过程中存在的问题,提出在单一层位标定方法基础上的综合地质、VSP、合成记录资料的综合层位标定方法.     

储油罐变位识别与罐容表标定的数学建模

针对2010年数模竞赛A题,使用二重积分、近似积分及坐标变换方法,求出储油罐发生变位时储油量与油面高度的函数关系.利用最小二乘法原理建立了求解最优参数和的约束规划模型,进而对罐容表重新标定.     

采用定波长传感技术研制污水活性测定仪

利用波长为485 nm的光具有最大吸收峰的特点,使用污水生物活性甲月替萃取液研制了定波长光吸收传感器,该传感器将萃取液中的生物活性转换为电信号。并在此基础上,研制成功了智能化的污水活性测定仪,实现了生物活性指标的直读、存储及打印输出功能。并对硬件和软件设计进行综合考虑,实现了简便、准确的仪器标定。     

基于序列图像的粮堆三维重建技术研究

研究基于粮堆序列图像的三维重建问题.重点阐述了三维重建过程中的几个关键步骤,如角点检测、基础矩阵估计和摄像机自标定等,提出一种基于去除异常点的基础矩阵估计方法,接着采用摄像机自标定方法求解摄像机投影矩阵,进而借助投影矩阵和图像特征点计算三维空间点坐标,完成重建过程,给出了基于真实的粮堆图像的三维重建结果.     

冶炼机器人位姿标定及运行可靠性

对冶炼用CS－1双擘工业机器人现场使用中的位姿标定及运行可靠性进行了研究。提出了一种简便有效的现场标定计算模型和标定方法对机器人进行位姿标定,由标定变换矩阵补偿同一测点的实际值和计算值的误差,可同时减少机器人定位误差和由臂杆几何参数偏差所引起的运动误差,显著提高需进行连续路径控制的机器人的现场定位精度和位置跟踪精度。此外,提出了用增加机器人现有硬件的冗余功能和设置敏感器件的替代功能以提高机器人现场运行可靠性的方法。实践证明,该方法能提高恶劣环境下易失效部件的可靠度,进而提高机器人的整机使用性能。