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1.
A new distributed equipment condition monitoring and fault diagnosis network system based on an RS485 field bus and an industrial ethernet was designed for the main drive system of a hot strip mill. The system structure and composition were studied. The following problems were resolved: communication of an intelligence data acquisition module with RS485 interface; communication between a server, clients and a light emitting diode; and point to point communication between a programmable logic controller and server. Real time signals of 24 radial run out, 12 axial drifting can be synchronously acquisitioned and stored in a database. System operation is satisfactory and can be used to identify the causes of rolling mill halt and transmission slip brake, and to improve sheet metal quality.  相似文献   

2.
Abstract:To manage suppliers who are involved in product collaborative design and innovation, on the basis of collating and analyzing 35 literatures related to co design process and supplier management activities, a three tier model of supplier management in collaborative product development is put forward, which includes tiers of long term strategic management, product development project and co design task. In terms of collaborative product development process, an overall management activities model about suppliers is built. Methods of supplier selection and performance evaluation are studied. A case study related to supplier management in equipment co design from a steel company is provided to verify the theory and methods.  相似文献   

3.
In this paper the theory of Fuzzy Mathematics is used to set up the case-based reasoning(CBR) mathematic model system on the price-estimation of the land-rental and the related process and conditions of its application are suggested.The calculation example of CBR in land business demonstrates that the CBR model is effective;it can be used as the reference for the decision-making on estimating the price in land business.  相似文献   

4.
Concept of stability is vague, but it is basic characteristic of dynamic system, and precondition that make all kinds of control system run normally. Today it is still a challenge to analyze stability for uncertainty complex control system, whose mathematic modeling is impossible or very difficult, so it is very hard to judge whether a system running is stable or not by mathematic stability criterion. A kind of analyzing method is presented, which combine absolute stability with self-locked concept of heuristic search, it may analyze system stability in more range through adjusting self-collected loop parameters for uncertain control system based on knowledge control model. It is shown that stability analyzing method is effective and suitable for practical physical system in the engineering project.  相似文献   

5.
Because there are lots of difficulties in mathematic modeling for uncertainty complex object, so it is not suitable to utilize traditional methods in some aspect such as identification, analysis, synthetical design and implementation. Especially, for the idea of system modeling, it is very different in comparison with traditional mathematic modeling, therefore, it is very difficult to study control problem for uncertainty system in technology and theory. On the basis of summarizing characteristics of uncertainty complex object, present to establish generalized control model, and apply intelligent control strategy to implement control effectively. In addition, authors also studied control algorithm and system structure. Engineering practice shows that it is effective and successful to establish generalized control model, and select intelligent control strategy for uncertainty control system.  相似文献   

6.
Zhu Bing  Li QiMing 《保鲜与加工》2005,(4):102-105110
During construction process,there is a "principal-agent" relation between clients and constraints.Between the two parties,there exists moral risk under asymmetric information.This paper builds a "moral risk model" between clients and constraints during the construction process by applying "principal-agent theory" in the information economics theory.On the basis of quantitative analysis of the model,this paper draws some conclusions,which is benefitial to the enhancement of the level of project management.At last,this paper proposes some advice on reducing the moral hazard of the constraints.  相似文献   

7.
This paper introduces the structure and operating principle of double eccentric mechanism used in a special environment to realize the two-dimension precision adjustment, establishes its precise mathematic model, analyzes the theory model with simulation model, and researches it by test. All of which indicate that the operating principle and mathematic model of double eccentric two-dimension precision adjustment mechanism are right. Under the condition of some processing and control accuracy, the adjusting error can satisfy the requirement. Through analyzing on the test data, it shows the circular degree and eccentric errors are the main sources of adjusting errors.  相似文献   

8.
As the important method and instrument of agile manufacture,the technology of distributed collaborative design and manufacturing has become the hotspot of manufacturing. The basic concept and key technologies of IP_VPN are introduced in this paper,and a collaborative design network model based on IP_VPN is presented. Distributed collaborative design is a multi_user,multitask involved system, which is consisted of lots of collaborative processs,so the network security is the key of distributed collaborative design. We research on the security of collaborative design network based on IP_VPN, hence get a conclusion:we can construct an economical?practical and secure collaborative design network system by the application of data encryption,user authentication and access control based on the role,etc.  相似文献   

9.
In this paper, the authors discuss the principium of browser/server model and expatiate on the characteristic of browser/server model. Elucidated the concept and connotation of integrated quality system, and emphatically researched the system structure and function model of the integrated quality system based on browser/server model.  相似文献   

10.
11.
dSPACE is a prototype development and real-time control testing platform which is based on MATLAB/Simulink software. By establishing mathematic model of hydraulic automatic transmission system, the shift rules are achieved. A testing platform for hydraulic automatic transmission system is developed whose control software is programmed by simulink and using the dSPACE as the centre controller. The experiment of electric throttle control and power performance matching control of hydraulic automatic transmission system is carried out. the result shows that well matching performance of hydraulic automatic transmission system can be realizedby using the control strategy proposed in this paper, it provides a fast and efficient approach for researching and developing the hydraulic automatic transmission system.  相似文献   

12.
Based on the analysis of dynamics method of pneumatic transmission, the mathematic model of air brake Load Sensing Proportional Valve (LSPV) is established by fluid servo control theory. The air brake LSPV of one All Terrain Vehicle (ATV) is simulated with the platform of advanced modeling ervironment for performing simulations of engineering system(AMESim), then the input and output pressure characteristic curve of the valves are obtained. The characteristic curve shows, with the load increasing, the pressure adjustment point of Load Sensing Proportional Valve (LSPV) moves up. When the pressure reaches into the pressure adjustment point, the increase rate of output pressure is less than the increase rate of input pressure, so that it can effectively prevent the lockup of the rear wheel precede the front wheel. The result of the simulation is consistent with the experiment result. The validity of the model is verified, which provide foundation for the simulation of the air brake elements and brake system.  相似文献   

13.
The space of mountain center city has diversified characteristics, which has interactive relations with the city overall function. Based on analyzing the contradictions between the characteristics of central city and the form of mountainous city, following the mountainous central cities' characteristics of multi-group, multi-center, multi-dimensional and multi-level, the theoretical model which reflects mathematic and abstract relationship between the characteristics and the overall function of the mountainous central cities was constructed. On the basis of the mountainous cities' characteristics and the scientific planning, the model develops the mountainous cities space and macro-functions theory.  相似文献   

14.
A mathematic model for filtering reducer transmission robots which have the characteristics of parameter uncertaintiesexternal disturbancestrong couplingnonlinearities and multi-variable is establishedand then an adaptive RBF networks backstepping method is proposed to control the robot.RBF is employed to approach the nonlinear item of the filtering reducer transmission robot on lineand an adaptive RBF network controller is developed based on backstepping method which effectively suppresses the effect of parameter uncertainties and external disturbance etc.It is combined with Lyapunov stabilization analytical method to demonstrate the close loop system convergence.Simulation results verify that the proposed controller not only satisfies high performance position trackingbut also has good accuracy and robustness.  相似文献   

15.
A dynamic control arithmetic and mathematic model of secondary cooling system for ROKOP billet concasting has been developed in view of the changes of casting speed during concasting process and the high fluctuation of surface temperature due to the use of static control method. By means of computer simulation and by comparison between static and dynamic control method, it proves that the latter one is more adaptive to the changes of casting speed, which leads to lower fluctuation of surface temperature.  相似文献   

16.
The dynamic data exchange is the key to the realization of the collaborative design based on Internet. The features of data for collaborative design based on Internet are analyzed. The data transformation, the data transmission and the data transaction of collaborative design based on Internet are researched. The system configuration and organization mode of dynamic data exchange for collaborative design Internet-based are developed, in which, STEP serves as the product data exchange standard, and ORACLE is the kernel database of the system, so that each of the CAD systems can synchronously access the ORACLE database, share and exchange the design information. The STEP-ORACLE serves as the organizing mode of dynamic data exchange for the collaborative design based on Internet, which realizes the real-time exchange and consistency of the dynamic data between the different platforms and CAD systems.  相似文献   

17.
In this paper according to different cooling feafures in the secondary coolingzone,a two-dimensional mathematic model of heat transfer is developed,which is suitable for the op-eration of the casfer in Chongqin g Special Steel Plant,In the model, a finite difference method isadopted and different boundary conditions a different time-step is firstly used.Thus the model isof high precision with a shorter calculation time.The optimum secondary cooling system of the con-tinuous billet can be gained by aimulating and optimizing calculations using the model.  相似文献   

18.
A method of constructing GPS-based positioning services system by means of JAVA technology is introduced in this paper. The position data, which are sent from GPS satellites, are received by GPS receiving terminal and are analyzed by mobile computing client developed on J2ME in accordance with the differential GPS algorithm. The client submits special position querying information to position server in way of wireless GPRS network. After computing and data querying, the server developed by J2EE returns results to the mobile device. Then, the mobile computing client displays the position map or carries out further processing. All of these form a highly precise location-based services system.  相似文献   

19.
A test bed with computer control for hydraulic torque converter test is built up. The structure and principle of the test bed are introduced. The performance characteristic of torque converter for a CVT car is studied, and the mathematic model of the torque converter is established based on test results, which lays a foundation for the exploitation of automatic transmission car with hydraulic torque converter.  相似文献   

20.
面向协作定价的上海蔬菜供应链整合研究   总被引:1,自引:1,他引:0  
通过对上海地区蔬菜供应链结构的调研,分析了几种典型蔬菜供应链结构的优势和存在的问题。以批发市场占主导的上海蔬菜供应链为例,从供应链整合中最核心的协作定价策略出发,运用二层规划模型对该供应链进行协作定价的决策分析,以期确定能实现供应链整体收益和各主体收益稳定增长的合理价格,并提出了能保护农民和市民利益的理想蔬菜供应链结构。  相似文献   

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