Continuous cast width control using a data mining approach

Abstract

Twelve per cent chrome ferritic (non-stabilised) stainless steel cast at the continuous caster at Columbus Stainless exhibited notable differences in the width change between consecutive heats. The reason for these differences is related to the fact that the steel is in a dual phase region between austenite and ferrite during the solidification stages of the continuous casting process. A model was developed and is currently used as a production tool to predict the width change of a 12% chrome ferritic heat before it is cast based on heat composition. The strand width is altered based on the model predictions by changing the secondary cooling pattern. It was uncertain if the current model is the best suited for this application and a study was carried out using different but more advanced data mining techniques in an attempt to improve the existing model. It was found that advanced data mining techniques could not improve the original rule based model.     

中央空调空气处理机组的DDC设计

讨论了对智能建筑中央空调系统中的空气处理机组实现直接数字控制的基本原理,阐述了直接数字控制器硬件和软件的设计方法,并详细介绍了一种关于室温控制的复合模糊控制算法。     

Modelling and control of coiling entry temperature using interval type-2 fuzzy logic systems

Abstract

The set-up of the cooling water applied to the strip as it traverses the runout table in order to achieve the coiler entry temperature was made by an intelligent model implemented using interval type-2 fuzzy logic systems. The model uses as inputs the targets for coiling entry temperature, strip thickness, finish mill exit temperature and finishing mill exit speed. The experiments of this application were carried out for three different types of coil in a real hot strip mill. The results proved the feasibility of the system developed for coiler entry temperature prediction. Comparison with the online type-1 fuzzy logic based model shows that the proposed interval type-2 fuzzy logic system improves performance in coiler entry temperature prediction under the tested condition.     

Concurrent Map Building and Behavior Learning for Navigation in Unknown Environments

In this paper, we report a robust and low-cost navigation algorithm for an unknown environment based on integration of a grid-based map building algorithm with behavior learning. The study focuses on mobile robots that utilize ultrasonic sensors as their prime interface with the outside world. The proposed algorithm takes into account environmental information to augment the readings from the low angular accuracy sonar measurements for behavior learning. The environmental information is obtained by an online grid-based map learning design that is concurrently operating with the behavior learning algorithm. The proposed algorithm is implemented and tested on an in-house-built mobile robot, and its performance is verified through online navigation in an indoor environment.     

Self-adaptive neuro-fuzzy systems for autonomous underwater vehicle control

This paper presents a systematic approach for developing a concise self-adaptive neurofuzzy inference system (SANFIS) with a fast hybrid parameter learning algorithm for on-line learning of the control knowledge for autonomous underwater vehicle (AUV) control. The multi-layered network structure of SANFIS incorporates fuzzy basis functions for better function approximations. We investigate three SANFIS structures with three different types of fuzzy IF-THEN rule-based models and cast the rule formation problem as a clustering problem. A recursive least-squares algorithm and a modified Levenberg-Marquardt algorithm with limited memory are exploited to accelerate the parameter learning process. This hybrid parameter learning algorithm together with an on-line clustering technique and rule examination provide SANFIS with the capability of selforganizing and self-adapting its internal structure (i.e. the fuzzy rules and term sets) for learning the required control knowledge for an AUV to follow desired trajectories. Computer simulations for modeling a control system for an AUV have been conducted to validate the effectiveness of the proposed SANFIS.     

基于信息熵和模糊层次分析的5G终端性能网格化评价算法

5G终端性能评价在网络优化领域发挥着重要作用。本文提出了一种基于信息熵和模糊层次分析(FUZZY AHP)算法的网络大数据5G终端性能网格化评价方法。首先,我们构建并改进了5G终端评估系统,将5G驻留时间作为KPI引入到终端评估系统中,然后提出了基于信息熵和FUZZY AHP算法来训练评估系统因子权重,应用该方法,因子权重可以比基于终端评估系统的经验直接获得的结果更准确、更客观,在评估算法中引入了位置网格法,可以消除网络和用户分布的影响。采用终端抽样测试和投诉工单选择的方法,在算法结果的基础上,提高了性能相对较差的手机的选择精度。     

A Localization Algorithm for Autonomous Mobile Robots via a Fuzzy Tuned Extended Kalman Filter

The capability to acquire the position and orientation of an autonomous mobile robot is an important element for achieving specific tasks requiring autonomous exploration of the workplace. In this paper, we present a localization method that is based on a fuzzy tuned extended Kalman filter (FT-EKF) without a priori knowledge of the state noise model. The proposed algorithm is employed in a mobile robot equipped with 16 Polaroid sonar sensors and tested in a structured indoor environment. The state noise model is estimated and adapted by a fuzzy rule-based scheme. The proposed algorithm is compared with other EKF localization methods through simulations and experiments. The simulation and experimental studies demonstrate the improved performance of the proposed FT-EKF localization method over those using the conventional EKF algorithm.     

碳势模糊控制及数字仿真

用数字仿真的方法论述了碳势采用模糊控制能取得比较理想的控制效果。通过数字仿真可以优化模糊控制器的控制参数,加快系统调试过程。     

S7—200pH自动控制系统

以一实测中和滴定曲线为例,引出缓冲指数及平衡迟缓的概念。从而说明酸碱中和（ｐＨ）控制的困难性。然后文章指出一般的位式控制和常规的反馈控制难以克服ｐＨ控制对象的强非线性和大滞后特性。因此研制一种既可用于一般工业过程又经济的ｐＨ控制系统十分必要。最后文章简要地介绍了作者研制Ｓ７２００ｐＨ控制系统,在间歇流程及连续过程中使用的控制系统方案、软件程序框图及使用情况。同时指出Ｓ７２００ｐＨ系统的优异特性及尚待研究的有关问题。     

Local maneuvers planning: application to an autonomous wheelchair moving in constrained spaces

The problem approached in this paper is the simulation of maneuvers planning for an autonomous mobile robot moving in constrained spaces free of obstacles. The robot treated is an autonomous wheelchair for the disabled. Our approach is based on the principle that a maneuver is the concatenation of elementary moves with reversal. So, to perform a maneuver that enables reaching a final state, we have defined five elementary moves. The developed planner is built around a perception system, a guidance system and a locomotion system. Each elementary move is implemented using a fuzzy controller.