预磨机模糊控制系统的设计与试验

针对目前磨矿设备中存在的控制模型相对简单、控制精度低、磨矿工序的效率较差等问题,采用模糊控制算法设计了控制模型。根据模糊控制理论,分别设计了给料及主轴转速的模糊控制器,并采用并行连接方法组成了一个两输入两输出的模糊控制系统。以江西理工大学研制的RM500预磨机为样机的Matlab仿真表明,与常规的PID控制相比,模糊控制明显改善了预磨机的静态和动态性能,并且具有更强的自适应能力和鲁棒性;进一步的实际钨矿石预磨试验表明,在模糊控制系统控制下,预磨机工作电流稳定,产品质量优异。

人机交互等待状态的用户体验研究和设计对策

随着国内通讯技术、互联网技术、移动互联网技术、包括近两年火起来的云计算技术与及信息处理技术的快速发展;各种信息客户端产品;以及运行在这些设备上各种网站和APP产品使得人们的生活节奏越来越高效;这样的变化使人们不能忍受在使用产品过程中的缓慢交互的过程;因为等待会打断人们业务操作的流程;影响工作完成的效率;所以对网站、APP、和运行IT系统的服务来讲;等待过程的体验是一个急需改善的问题。对此;本文对交互等待环节进行深入系统的分析研究;归纳出适用于交互等待状态的科学、系统、合理、可行的设计方法和策略。

浅析DMR2000数字调制器控制接口板

文章详细的介绍了DMR2000大功率短波发射机数字调制器控制接口板的功能及输入输出接口设计。通过文章的详细分析,总结,希望能够给相关方面研究人员带来一定的借鉴,供大家参考。

Multi-loop Internal Model Controller Design Based on a Dynamic PLS Framework

In this paper,a multi-loop internal model control(IMC) scheme in conjunction with feed-forward strategy based on the dynamic partial least squares(DyPLS) framework is proposed.Unlike the traditional methods to decouple multi-input multi-output(MIMO) systems,the DyPLS framework automatically decomposes the MIMO process into a multi-loop system in the PLS subspace in the modeling stage.The dynamic filters with identical structure are used to build the dynamic PLS model,which retains the orthogonality among the latent variables.To address the model mismatch problem,an off-line least squares method is applied to obtain a set of optimal filter parameters in each latent space.Without losing the merits of model-based control,a simple and easy-tuned IMC structure is readily carried over to the dynamic PLS control framework.In addition,by projecting the measurable disturbance into the latent subspace,a multi-loop feed-forward control is yielded to achieve better performance for disturbance rejection.Simulation results of a distillation column are used to further demonstrate this new strategy outperforms conventional control schemes in servo behavior and disturbance rejection.

Adaptive controller design based on input-output signal selection for voltage source converter high voltage direct current systems to improve power system stability

An input-output signal selection based on Phillips-Heffron model of a parallel high voltage alternative current/high voltage direct current(HVAC/HVDC) power system is presented to study power system stability. It is well known that appropriate coupling of inputs-outputs signals in the multivariable HVDC-HVAC system can improve the performance of designed supplemetary controller. In this work, different analysis techniques are used to measure controllability and observability of electromechanical oscillation mode. Also inputs–outputs interactions are considered and suggestions are drawn to select the best signal pair through the system inputs-outputs. In addition, a supplementary online adaptive controller for nonlinear HVDC to damp low frequency oscillations in a weakly connected system is proposed. The results obtained using MATLAB software show that the best output-input for damping controller design is rotor speed deviation as out put and phase angle of rectifier as in put. Also response of system equipped with adaptive damping controller based on HVDC system has appropriate performance when it is faced with faults and disturbance.

Nonlinear Control of Induction Motor： A Combination of Nonlinear Observer Design and Input-Output Linearization Technique

This paper deals with a nonlinear control strategy of induction motor that combines an input-output linearization control technique and a nonlinear observer design. It is well known that induction motors are the most widely used motors in electrical appliances, industrial control and automation. However, it is also known that induction motor control is a complex task that is due to its nonlinear characteristics. Two main features of the proposed approach are worth to be mentioned. Firstly, a nonlinear control is carried out using a nonlinear feedback linearization technique involving non available state variable measurements of the induction motor system. Secondly, a nonlinear observer is designed to estimate these pertinent but unmeasurable state variables of the machine. The circle-criterion approach is performed to compute the observer gain matrices as a solution of LMI （linear matrix inequalities） that ensure the stability conditions, in the sense of Lyapunov, of the estimated state error dynamics of the designed observer. Simulation results are presented to validate the effectiveness of the proposed approach.

A cross-layer approach to enable multipacket transmission in MIMO-SDMA based WLAN

We propose a medium access control(MAC) protocol for uplink transmissions in wireless local area networks(WLANs),where both stations and access points(APs) are equipped with multiple antennas. The protocol solves some common problems in utilizing multiple input multiple output(MIMO) under the 802.11 protocol,e.g.,how to deploy preamble(training sequence) used for channel estimation and how to enable simultaneous data transmissions,and facilitates two simultaneous uplink data transmissions via a cross-layer approach. Furthermore,we develop a 3D discrete-time Markov model to analyze the per-formance of the proposed WLAN scheme. The analytical results are verified by simulation,and numerical results show that the system throughput can be significantly improved by our proposed scheme as compared with conventional schemes.