转型背景下“计算机工业控制技术”课程教学改革探索

“计算机工业控制技术”是测控技术与仪器等控制类专业的重要专业课,在课程体系中占有非常重要的地位。为了更好地培养优秀的应用型人才,在阐述该课程的重要性及在教学过程中存在问题的基础上,从教学内容、教学方式、教学手段及考核方式等方面对课程教学进行新的探索。这样能有效地激发学生的学习热情,提高学生分析问题、解决问题的综合能力,对提高“计算机工业控制技术”课程教学质量具有重要的意义。

Iterative learning control of SOFC based on ARX identification model

This paper presents an application of iterative learning control (ILC) technique to the voltage control of solid oxide fuel cell (SOFC) stack. To meet the demands of the control system design, an autoregressive model with exogenous input (ARX) is established. Firstly, by regulating the variation of the hydrogen flow rate proportional to that of the current, the fuel utilization of the SOFC is kept within its admissible range. Then, based on the ARX model, three kinds of ILC controllers, i.e. P-, PI- and PD-type are designed to keep the voltage at a desired level. Simulation results demonstrate the potential of the ARX model applied to the control of the SOFC, and prove the excellence of the ILC controllers for the voltage control of the SOFC.

Control synthesis for polynomial nonlinear systems and application in attitude control

A method for positive polynomial validation based on polynomial decomposition is proposed to deal with control synthesis problems. Detailed algorithms for decomposition are given which mainly consider how to convert coefficients of a polynomial to a matrix with free variables. Then, the positivity of a polynomial is checked by the decomposed matrix with semidefinite programming solvers. A nonlinear control law is presented for single input polynomial systems based on the Lyapunov stability theorem. The control synthesis method is advanced to multi-input systems further. An application in attitude control is finally presented. The proposed control law achieves effective performance as illustrated by the numerical example.

A Fault Detection and Isolation Scheme Based on Parity Space Method for Discrete Time-delay System

A Fault detection and isolation(FDI)scheme for discrete time-delay system is proposed in this paper,which can not only detect but also isolate the faults.A time delay operator is introduced to resolve the problem brought by the time-delay system.The design and computation for the FDI system is carried by computer math tool Maple,which can easily deal with the symbolic computation.Residuals in the form of parity space can be deduced from the recursion of the system equations.Further more,a generalized residual set is created using the freedom of the parity space redundancy.Thus,both fault detection and fault isolation have been accomplished.The proposed method has been verified by a numerical example.

Geospacial information utilized under the access control strategy

This paper introduces a solution to the secure requirement for digital rights management （DRM） by the way of geospacial access control named geospacial access control （GeoAC） in geospacial field. The issues of authorization for geospacial DRM are concentrated on. To geospacial DRM, one aspect is the declaration and enforcement of access rights, based on geographic aspects. To the approbation of digital geographic content, it is important to adopt online access to geodata through a special data infrastructure （SDI）. This results in the interoperability requirements on three different levels： data model level, service level and access control level. The interaction between the data model and service level can be obtained by criterions of the open geospacial consortium （OGC）, and the interaction of the access control level may be reached by declaring and enforcing access restrictions in GeoAC. Then an archetype enforcement based on GeoAC is elucidated. As one aspect of performing usage rights, the execution of access restrictions as an extension to a regular SDI is illuminated.

A Loosely Coupled Control Architecture Based on Agent and CORBA for Multiple Robots

With the rapid development of information technology, adopting advanced distributed computing technology to construct robot control system is becoming an effective approach gradually. This paper proposes a distributed loosely coupled software architecture based on Agent and CORBA to control multiple robots. This model provides the robot user with agent control units at the semantic level and CORBA provides function interfaces to agent at the syntax level, which shows a good adaptability, flexibility and transparence.

Intelligent manufacturing system of impeller for computer numerical control(CNC) programming based on KBE

To solve the problem of advanced digital manufacturing technology in the practical application, a knowledge engineering technology was introduced into the computer numerical control(CNC) programming. The knowledge acquisition, knowledge representation and reasoning used in CNC programming were researched. The CNC programming system functional architecture of impeller parts based on knowledge based engineering(KBE) was constructed. The structural model of the general knowledge-based system(KBS) was also constructed. The KBS of CNC programming system was established through synthesizing database technology and knowledge base theory. And in the context of corporate needs, based on the knowledge-driven manufacturing platform(i.e. UG CAD/CAM), VC++6.0 and UG/Open, the KBS and UG CAD/CAM were integrated seamlessly and the intelligent CNC programming KBE system for the impeller parts was developed by integrating KBE and UG CAD/CAM system. A method to establish standard process templates was proposed, so as to develop the intelligent CNC programming system in which CNC machining process and process parameters were standardized by using this KBE system. For the impeller parts processing, the method applied in the development of the prototype system is proven to be viable, feasible and practical.

Design and control of multiple spacecraft formation flying in elliptical orbits

Spacecraft formation flying is an attractive new concept in international aeronautic fields because of its powerful functions and low cost. In this paper, the formation design and PD closed-loop control of spacecraft formation flying in elliptical orbits are discussed. Based on two-body relative dynamics, the true anomaly is applied as independent variable instead of the variable of time. Since the apogee is considered as the starting point, the six integrating constants are calculated. Therefore, the algebraic solution is obtained for the relative motion in elliptical orbits. Moreover, the formation design is presented and both circular formation and line formation are provided in terms of an algebraic solution. This paper also discusses the PD-closed loop control for precise formation control in elliptical orbits. In this part, the error-type state equation is put forward and the linear quadratic regulator （LQR） method is used to calculate PD parameters. Though the gain matrix calculated from LQR is time-variable because the error-type state equation is time variable, the PD parameters are also considered as constants because of their small changes in simulation. Finally, taking circular formation as an example, the initial orbital elements are achieved for three secondary spacecraft. And the numerical simulation is analyzed under PD formation control with initial errors and J2 perturbation. The simulation results demonstrate the validity of PD closed-loop control scheme.

A hybrid stochastic fractal search and pattern search technique based cascade PI-PD controller for automatic generation control of multi-source power systems in presence of plug in electric vehicles

A hybrid Stochastic Fractal Search plus Pattern Search （hSFS-PS） based cascade PI-PD controller is suggested in this paper for Automatic Generation Control （AGC） of thermal, hydro and gas power unit based power systems in presence of Plug in Electric Vehicles （PEV）. Firstly, a single area multi-source power system consisting of thermal hydro and gas power plants is considered and parameters of Integral （I） controller is optimized by Stochastic FractaI Search （SFS） algorithm. The superiority of SFS algorithm over some recently proposed approaches such as optimal control, differential evolution and teaching learning based optimization techniques is demonstrated by comparing simulation results for the identical power system. To improve the system performance further, Pattern Search （PS） is subsequently employed. The study is further extended for different controllers like PI, PID, and cascaded PI-PD controller and the superiority of cascade PI-PD controller over conventional controllers is demonstrated. Then, cascade PI- PD controller parameters of AGC searched using the proposed hSFS-PS algorithm in presence of plug in electric vehicles. The study is also extended to an interconnected power system. It is seen from the comparative analysis that hSFS-PS tuned PI-PD controller in single and multi-area with multi sources improves the system frequency stability in complicated situations. Lastly, a three area interconnected system with PEVs with dissimilar cascade PI-PD controller in each area is considered and proposed hSFS- PS algorithm is used to tune the controller parameters in presence of nonlinearities like rate constraint of units, dead zone of governor and communication delay.

Computer Audit Risk Control Research

The development of computer information technology makes the information of the audited unit more and more high. The introduction of accounting computerization information system makes the processing of enterprise economic business more convenient and efficient. Here came the computer controlled environment audit new risks, of course, the computer technology applied to the audit work to improve the audit efficiency by a lot, but also increased the complex information technology environment audit risk. Starting from the concept of computer audit risk, this paper analyzes and discusses the new risks and causes of audit under the computer condition, and puts forward some constructive risk control measures.

Service-based flexible workflow system for virtual enterprise

Using the services provided by virtual enterprises, we presented a solution to implement flexible inter-enterprise workflow management. Services were the responses of events that can be accessed programmatically on the Internet by HTTP protocol. Services were obtained according to some standardized service templates. The workflow engine's flexible control to a request was bound to appropriate services and their providers by using a constraint-based, dynamic binding mechanism. Hence, a flexible and collaborative business was achieved. The workflow management system supports virtual enterprise, and the styles of virtual enterprises can be adjusted readily to adapt various situations.

Application of workflow technology for workshop scheduling

This paper attempts to solve the complexity of scheduling problems and meet the requirement of the ever-changing manufacturing environment. In this paper, a new Workflow-Based Scheduling System (WBSS) is proposed. The integration of Workflow Management System (WfMS) and rule-based scheduler provides us an effective way of generating a task-sheet according to the states of system and the scheduled objects. First, the definition of workflow model for scheduling is proposed, and following are the architecture and mechanism of the proposed WBSS. At last, an application is given to show how the established system works.

A Sliding Mode Control for Uncertain Time-delay Systems

By means of the feasibility of some linear matrix inequalities(LMIs),delay dependent sufficient condition is derived for the existence of a linear sliding surface,which guarantees quadratic stability of the reduced-order equivalent system restricted to the sliding surface.And a reaching motion controller is proposed.A numerical simulation shows the effectiveness of the approach.

Development of testing techniques for mine fan performance

Three progressive stages of testing techniques are elaborated,which are en-tirely manual operating,taking separate instruments testing and computer program con-trolling.The testing method and principle are detailed based on the testing process formeteorological parameters,air pressure,air quality and rotating velocity.And every testingtechnique is analyzed.Finally, the technique outlook is viewed.All this plays a leading rolein development of the testing techniques.

Design and Implementation of Computer Network Traffic Monitoring

This paper focuses on the key technologies of P2P and network traffic monitoring, research and analyze the traditional P2P flow control technology and the working principle of deployment, discuss on the straight loss and bypass interference control technology, and the reasonable combination of two kinds of technology to design straight bypass joint deployment. On basis of it, we design a new P2P traffic monitoring system. Through the design and implementation of computer network traffic monitoring system based on C/S mode to achieve automatic control, maintenance, and monitor network traffic, which is suitable for the current engineering software to monitor a network application environment. From the network users and network operator＇ s perspective, monitoring of network traffic is scientific, reasonable that improve network management and it has important research value.

Research on the interaction design of somatosensory games——With the original game ＂Dream＂ in the center

The emergence of the somatosensory interactive technology has changed the ways of the interaction between the users and the computers, so that people can control the computers more freely. This paper focuses on the interactive design of the somatosensory games, and combines the Kinect interactive devices with the popular Unity 3D game engines, and analyzes and designs the realization principles of the somatosensory games, the somatosensory games and the digital somatosensory interactive display. Through the design and production of the original game ＂Dream＂, the author discusses the design methods of the game interactive experience while abandoning the traditional human-comouter interactive mode.