Vibration reduction in a flexible-link mechanism through synthesis of an optimal controller

In this paper, reduction of vibration of a flexible planar mechanism is achieved through synthesis of an optimal controller. A finite element model, based on the equivalent rigid-link system theory, is used to accurately describe the dynamic behavior of the system. The model, which accounts for geometric and inertial nonlinearities of the mechanism, has been fully validated through experimental tests. In order to be able to employ the classical optimal control theory, a suitable linear model has been derived from the original one by means of a suitable linearization procedure. Vibration reduction can then be obtained by first defining an adequate performance index, which accounts for vibration amplitude, then by solving Riccati’s equation in order to find the controller that minimizes the performance index, i.e. the optimal controller. The results of several tests that have been carried out are also reported, to show the effectiveness of the synthesized control system.     

电力谐波实验台研究与设计

电力谐波实验台是一种通过模拟实际电网中产生的谐波电流并对其进行实时抑制的实验装置。该实验装置采用公共基础台+功能挂件的设计方式,结构紧凑,集成度高,扩展性好,能够完成电力谐波的产生、在线检测、分析、有源滤波等多项实验。装置软件实现由DSP控制器和上位机两部分组成。DSP控制器采用自适应滤波理论的单神经元电力谐波动态检测算法和滞环控制算法实现系统的补偿。上位机负责计量、监测、显示、储存等功能,是实验装置虚拟仪器的核心部分。该装置系统具有较高的教学使用和科研价值。     

并联型有源电力滤波器直流侧电压柔性控制策略

针对并联型有源电力滤波器的直流侧电压控制特点,提出了一种对直流侧电压进行柔性控制的并联型有源电力滤波器控制策略。该策略中,在直流侧电压控制部分引入反馈低通滤波器,削弱直流侧固有谐波对输出电流控制的影响;在电流控制的输出部分通过增加直流侧电压前馈系数,抵制在变换桥中可能引入的直流侧电压谐波影响。仿真结果表明直流侧电压柔性控制策略能够降低APF系统补偿后的电源电流总谐波畸变率,从而改善并联型有源电力滤波器的谐波补偿性能。     

模具专业的《数控加工》任务驱动教学探索

模具专业的《数控加工》课程传统教学模式存在很多不足,教学效果也不理想。为强化学生职业能力,提高就业竞争力,本文提出以模具加工生产实例为数控加工课程教学单元,从学习目标驱动与生产任务驱动两方面运用任务驱动教学方法进行了尝试与探索。     

大功率脉冲TEA CO2激光器控制系统设计

大功率脉冲TEA CO₂激光器不仅设备复杂,而且具有高电压、高激光功率、强电磁干扰的特点。本文采用工控机、可编程控制器和触摸屏,设计并实现了两级分布式大功率脉冲TEA CO₂激光器控制系统。详细阐述了系统硬件和软件的设计方案及实施过程。实际应用表明,该控制系统工作稳定可靠,具有较好的实际应用价值。     

基于NGB接入网的组播复制点研究

通过探讨分析下一代广播电视网(NGB)接入网的主要模式,揭示组播复制点在组播传输中的重要地位。重点分析了组播复制点和组播控制点的原理、规划,实际应用中的网络设计,面临的问题和解决方案。     

A novel Markov analytical model for the TCP/AQM systems

A novel closed-loop feedback TCP/AQM(Transfer Control Protocol/Active Queue Management) model is proposed in this paper using a discrete-time Markov chain,and a way to calculate the equilibrium distribution of this model is given.In the model,system time is divided into time slots,the bottleneck router queue model and TCP window size model in each slot are analyzed.Finally,by combining adjacent slots,an integrated TCP/AQM analytical model is developed.By this model,the average values of packets dropping rat...     

触摸调光控制芯片的设计与测试

电力作为一种方便的能源广泛应用于我们生活的各个方面,于是电能的节能变得尤为重要。由于家用照明设计可以从控制方面实现节能,因此人们可以根据自己不同时间的不同需要来调节灯光的亮度来达到节约电能的目的。本文提出了一种应用于家用照明亮度的调节控制芯片的设计方案,首先分析顶层模块的功能,再将其功能分类细化,分配到不同的子模块去实现,利用CMOS电压比较器来实现了过零检测、系统时钟脉冲产生、触摸控制等操作,并通过仿真软件验证了设计模块功能的正确性,最后经流片测试芯片功能满足设计要求。     

Tracking and controlling unstable steady states of dynamical systems

An adaptive controller for stabilization of unknown unstable steady states (spirals, nodes and saddles) of nonlinear dynamical systems is considered and its robustness under the changes of the location of the fixed point in the phase space is demonstrated. An analog electronic controller, based on a low-pass filter technique, is described. It can be easily switched between a stable and an unstable mode of operation for stabilizing either spirals/nodes or saddles, respectively. Numerical and experimental results for two autonomous systems, the damped Duffing–Holmes oscillator and the chaotic Lorenz system, are presented.