排序方式: 共有17条查询结果,搜索用时 0 毫秒
1.
本文简介了三种常用功率匹配泵(直控制式、双边阀控式和单边阀控式)的工作原理,并从实验和理论计算上对三种LS控制系统作分析比较。 相似文献
2.
测试了两台三位五通气动换向阀的流量特性。实验结果表明,被试三位五通换向阀各个通道的流量特性有较大差别。当压力比相同时,两个换向阀不同通道流量的最大差值分别为其最小流量的11.8%和26.6%。气动换向阀串联流道等效面积计算结果表明,不同通道之间的等效面积差别为8.9%,可见各流道结构参数没有得到合理匹配。本文根据实际结构,匹配了换向阀流道,提高了换向阀流道有效面积,并由此指出合理匹配各流道结构参数是提高气动换向阀整体流通能力的有效措施。 相似文献
3.
4.
5.
A general approach for controlling of periodical dynamic systems was presented by taking robotic yoyo as an example. The height
of the robot arm when the yoyo arrives at the bottom was chosen as virtual control. The initial amplitude of yoyo could be
mapped to the desired final amplitude by adjusting the virtual control. First, the yoyo motion was formulated into a nonlinear
optimal control problem which contained the virtual control. The reference trajectory of robot could be obtained by solving
the optimal problem with analytic method or more general numerical approach. Then, both PI and deadbeat control methods were
used to control the yoyo system. The simulation results show that the analytic solution of the reference trajectory is identical
to the numerical solution, which mutually validates the correctness of the two solution methods. In simulation, the initial
amplitude of yoyo is set to be 0.22 m which is 10% higher than the desired final amplitude of 0.2 m. It can be seen that the
amplitude achieves the desired value asymptotically in about five periods when using PI control, while it needs only one period
with deadbeat control. The reference trajectory of robot is generated by optimizing a certain performance index; therefore,
it is globally optimal. This is essentially different from those traditional control methods, in which the reference trajectories
are empirically imposed on robot. What’s more, by choosing the height of the robot arm when the yoyo arrives at the bottom
as the virtual control, the motion of the robot arm may not be out of its stroke limitation. The proposed approach may also
be used in the control of other similar periodical dynamic systems. 相似文献
6.
焊接电流有效值是电阻点焊最重要的工艺参数和控制变量.现行的焊接电流有效值测量方法均不能同时满足测控的准确性和实时性,严重影响焊接过程控制的平稳性和焊接质量.基于电阻焊焊接回路数学模型,提出电阻焊电流有效值算法--过零导数法,使用微型洛氏线圈直接测量电流变化率并据此实时计算电流有效值.采用仿真数值离线训练的人工神经网络在线计算模型参数,简便的信号检测方法和简洁的计算形式保证该算法良好的实时性和准确性.在以DSP为核心的点焊质量实时监控系统中实现了基于神经网络拟合函数的实时计算.实验结果证明该算法是有效的. 相似文献
7.
应用混合计算智能方法,进行大型发电机定子绝缘击穿电压预测以对其剩余寿命进行评估。为了解决在样本数较少及自变量间存在多重相关性时的击穿电压预测问题,文中通过将RBF神经网络和偏最小二乘(PLS)集成在一起,来计算PLS输入的外部模型权值,利用PLS方法提取变量成份来降低输入变量维数,这样消除了变量建模时的共线性,从而大大提高PLS的建模能力,同时利用RBF神经网络的非线性拟合能力来捕获变量投影空间的非线性关系。另外,在建模过程中对原始数据进行了中心化和压缩处理,以消除参数的量纲效应。大电机定子击穿电压预测试验结果表明:混合模型的预测结果明显优于传统的预测模型。 相似文献
8.
9.
10.