基于ARM-MCX514的机器人-数控协同系统运动控制器设计

由于机器人工作的复杂性日益增加,单个机器人的工作能力愈发显得不足,针对当前问题,提出将ARM微控制器与MCX514运动控制芯片相结合用于机器人-数控系统的协同运动控制。在硬件设计层面,以ARM微控制器与MCX514运动控制芯片为核心硬件,设计了芯片间的通信线路以及外围电路和接口。在软件设计层面,依托FreeRTOS嵌入式操作系统,采用多线程编程模式,由MCX514控制四自由度数控系统,ARM控制三轴的机械臂部分,利用握手式基坐标系标定方法实现机器人与数控系统的协同运动,并设计了配套的上位机程序。通过与ACR9000运动控制器的对比分析,证明所设计开发的控制器精度达到预期效果,具有一定的市场价值和应用前景。     

Formation and behavior of composite CO2 hydrate particles in a high-pressure water tunnel facility

Sinking CO₂ composite particles consisting of seawater, liquid CO₂, and CO₂ hydrate were produced by a coaxial flow injector fed with liquid CO₂ and artificial seawater. The particles were injected into a high-pressure water tunnel facility to permit determination of their settling velocities and dissolution rates. Injections were performed at fixed pressures approximately equivalent to 1200-m, 1500-m, and 1800-m depths and at temperatures varying from approximately 2 to 5 °C. Immediately after injection, the cylindrical particles were observed to break away from the injector tip and often aggregated into sinking clusters. The seawater flow in the tunnel was then adjusted in a countercurrent flow mode to suspend the particles in an observation window so that images of the particles could be recorded for later analysis. The flow would often break or cause rearrangement of some of the clusters. Selected individual particles and some clusters were studied until they became too hydrodynamically unstable to follow. In general, the flow required to suspend clusters or individual particles decreased with time as the particles dissolved. For example, one particle was produced and observed for over 6 min at an average pressure of 15.022 MPa and an average temperature of 5.1 °C. Its sinking rate, determined from the flow required for stabilization, changed from 37.2 to 3.3 mm/s over this time. Particle sinking rates were compared to correlations from the literature for uniform cylindrical objects. Reasonable agreement was observed for short times; however, the observed decrease in sinking velocity with time was greater than that predicted by the correlations for longer times. Particle dissolution rates, based on changes in diameter, were also determined and varied from 5 to . A pseudo-homogeneous mass transfer model was used to predict single-particle dissolution rates. Good agreement was achieved between experimental dissolution data and the modeling results.     

陕甘宁盆地中部马五14气层成岩相与有利储集区预测

陕甘宁盆地中部马五4^1气层成岩相主要包括准同生期近地表大气淋蚀次生孔隙相、成岩期浅埋次生孔隙相、表生期岩溶次生孔隙相、再埋藏早期次生孔隙相,再埋藏晚期次生孔隙相和复合型次孔隙相,不同类型成岩相的沉积学标志,地球化学特征,空间分布,演化序列和发育的控制因素不同,对气藏的最终形成所起的作用亦不同,其中,准同生期大气淋蚀次生孔隙相及成岩期浅埋次生孔隙相是形成气藏的基础,复合型次生孔隙相和表生期岩溶次生孔隙相是气藏的关键,再埋藏早期和晚期次生孔隙相是形成气藏的必要条件,诸类型成岩相的叠加和改造部位通常是气藏发育的是有利地区。     

On the solution of a quasi-tridiagonal system of linear equations

A method is described for solving a system of linear algebraic equations which is almost tridiagonal. Numerical results are presented for a number of test problems and some comparisons are made with the results obtained from algorithms proposed by other authors. A possible extension of the technique is briefly outlined.     

DI-720系列高速数据采集卡及其应用

DI-720系列高速数据采集卡具有与计算机接、采样位数多、支持多路输入并可人工设置等特点.所带有的波形记录分析软件(WWB)和程序开发包(SDK),使数据采集更灵活、方便.并以C++ Builder 5为开发语言,举例详细地说明了其在多通道故障信号采集中的应用,证实了该卡的灵活性和高性能等优点.     

宽基准电压范围D/A转换芯片MAX514及其应用

本文介绍了一种有12位精度、串行接口的四路D/A转换器MAX514,并介绍了其在麦克尔逊相移干涉测量相移器压电陶瓷驱动电源设计中的应用。