基于多关节机器人的能量最小消耗控制策略*

为了能够在有限的能量供给的情况下延长机器人运行时间,针对此类机器人在运动中的耗能问题,提出一种通过改进梯形升降速算法来实现多关节机器人能量最小消耗的控制方法。首先对多关节机器人的协调控制及能耗问题进行了研究,利用梯形升降速算法的速度函数与伺服电机耗能之间的关系推导出该算法的能量函数;然后通过求解能量函数最小值,得出梯形速度曲线基于能量最优的时间参数,利用该时间参数来设定伺服电机各运动阶段的时间,使机器人耗能最小。最后通过实验计算及分析,验证了所述控制策略在解决机器人耗能最小化问题上的有效性。     

混合式步进电机用于加工中心的试验与探讨

混合式步进电机与适宜的数控软硬件配套可较好地用于加工中心。为了进一步提高分辨率以及对于低阻尼的进给传动系统应采用细分技术。用单片机组成的智能化步进电机驱动器使机床在快速、精度和降噪方面达较高水平。     

Hydro- abrasive jet machining modeling for computer control and optimization

Use of hydro-abrasive jet machining (HAJM) for machining a wide variety of materials—metals, poly-mers, ceramics, fiber-reinforced composites, metal-matrix composites, and bonded or hybridized mate-rials—primarily for two- and three-dimensional cutting and also for drilling, turning, milling, and deburring, has been reported. However, the potential of this innovative process has not been explored fully. This article discusses process control, integration, and optimization of HAJM to establish a plat-form for the implementation of real-time adaptive control constraint (ACC), adaptive control optimiza-tion (ACO), and CAD/CAM integration. It presents the approach followed and the main results obtained during the development, implementation, automation, and integration of a HAJM cell and its computer-ized controller. After a critical analysis of the process variables and models reported in the literature to identify process variables and to define a process model suitable for HAJM real-time control and optimi-zation, to correlate process variables and parameters with machining results, and to avoid expensive and time-consuming experiments for determination of the optimal machining conditions, a process predic-tion and optimization model was identified and implemented. Then, the configuration of the HAJM cell, architecture, and multiprogramming operation of the controller in terms of monitoring, control, process result prediction, and process condition optimization were analyzed. This prediction and optimization model for selection of optimal machining conditions using multi-objective programming was analyzed. Based on the definition of an economy function and a productivity function, with suitable constraints relevant to required machining quality, required kerfing depth, and available resources, the model was applied to test cases based on experimental results.     

寒冬季节中对空冷岛的热态冲洗

某空冷机组位于冬季环境温度极低的地区,在直接空冷系统的调试过程中,需对空冷岛进行热态冲洗。在寒冬季节里,对空冷岛进行冲洗的前期准备工作中,需对采取防冻措施。实际应用后的效果证明,这些防冻措施相当有效。     

三种典型油源液压系统传动效率分析

基于理论分析和仿真,对变量泵油源(VD油源)、变频调速油源(INV油源)、启停式油源(ACC油源)三种不同油源组成的液压系统传动效率进行了分析计算。计算过程中,设定三系统均选用了同功率的定量泵,考虑各部件的效率和管路的压力损失,对VD油源、INV油源做了直接的效率分析和计算;针对ACC油源液压系统,对其核心元件——蓄能器的充放液过程作了仿真,并做了效率计算。最后从效率、主要部件的成本、频响等各方面综合比较了三种液压系统。理论计算表明,ACC油源液压系统由于利用了蓄能器储存的能力,有效地提高了液压系统效率。     

直接空冷闭环控制系统的应用和探讨

对漳山发电直接空冷控制系统控制、保护逻辑进行全面介绍，针对在实际运行中存在的问题，提出了相应的改进方案。     

ACC系统遮档技术的控制实现

介绍控制冷却工艺的特点及性能,着重分析了边部遮挡技术的设计思路及方法,并给出了具体的计算实现。     

新型荫罩式PDP放电单元谐振光子辐射和捕获过程研究

本文在流体模型计算的基础上采用蒙特卡罗模型,研究了彩色等离子体平板放电单元中的辐射和捕获过程.研究了新型荫罩式等离子体显示器(SMPDP)和传统的交流表面放电等离子体显示器(ACC PDP)的放电过程以及谐振光子的辐射和捕获特性.给出了电子及氙谐振态平均浓度以及相应空间浓度分布随时间变化情况.模拟了谐振光子和147谱线的分布情况.可以看到SMPDP的发光效率高于表面放电结构.     

直接空冷电厂的凝汽器热力计算方法

直接空冷电厂的凝汽器热力计算方法。