Applied Mechanics and Materials Vol. 421

Abstract: Networked Control System (NCS) has been drawn much attention in control field, and the performance of integrating control with network is particularly considered. The co-design of control and network performances of NCSs simultaneously possesses the theoretical and practical significance. In the paper, the main four NCS factors, i.e., network-induced delay, scheduling, sampling period, and packet loss rate, are investigated from the perspective of theoretical analysis and simulation. The simulations, based on the Truetime toolbox, show the effect of each factor on the NCS performance, which could provide a critical research basis for the further research in the co-design of NCS control and scheduling.

Abstract: Access control system applied in laboratory center makes laboratory management more conveniently. The laboratory security can be guaranteed, even the efficiency of laboratory management and human resource arrangement are also improved. How to use the hardware and software resources of access control system sufficiently, and conduct intelligent management combined with experiment courses, which need deeper research and actual intelligent management. In the paper, take the Beijing Experimental Teaching Center-Experimental Teaching Center of Electrical and Intelligent Engineering on Building as example, the co-design of Access Control System and experiment courses arrangement is proposed according to the database technology, and the intelligent management process is analyzed and realized.

Abstract: The research management system in the higher vocational college is the foundation to realize an efficient research management in the college. In this article, we suggest an implementation scheme based on the workflow technology for the research management system in the higher vocational college. First, we analyze the research management demand by the high-level college and then apply the workflow technology into the development of the research management system and on the basis of ASP.NET and SQL Server 2005, we complete this system. The system function conforms to the operation flow of the research management in the higher vocational college. Also with the good flexibility and reliability, it enables the system to have a flexible process restruction.

Abstract: The paper presents constraint satisfaction problem driven approach to analytical solution of the cyclic scheduling problem in the Flexible Manufacturing System (FMS) producing multi-type parts where for material handling are used the Automated Guide Vehicles Systems (AGVS). Finding the conditions guaranteeing the AGVs deadlock-free and collision-free movement policy is the aim of our researches. The AGVs co-sharing the common parts of the transportation route while executing repetitive processes, i.e. being assigned to AGVs passing along machines in a cyclic way, can be modeled in terms of Cyclic Concurrent Process Systems (CCPS). Schedulability analysis for a given CCPS answers the question whether a cyclic schedule exists or not. The paper suggests approach for schedulability analysis of multimodal processes representing real manufacturing employing the declarative modeling.

Abstract: The overall performance of large aerospace vehicles is determined to a great extent by the wings structure of aircrafts. In order to prevent wings vibration due to external interference, schemes of combined fuzzy-PID and fuzzy adapt PID controllers are proposed based on flexible beam structure. The MATLAB simulation model demonstrates that the proposed controllers not only has good dynamic characteristics, but also reduce the vibration effect greatly caused by external disturbance, which lay the foundation for the active vibration control of aircraft wings.

Abstract: Actual trends in manufacturing are characterized by production broadening, innovation cycle shortening, and the products having a new shape, material and functions. The production strategy focused on time needed change from the traditional functional production structure to flexible manufacturing cells and lines. Production by automated manufacturing system (AMS) is one of the most important manufacturing philosophies in the last years. The main goals of the project we are involved in lies on building a laboratory in which will be located a flexible manufacturing system consisting of at least two production machines with NC control (milling machines, lathe). These machines will be linked to a transport system and they will be served by industrial robots. Within this flexible manufacturing system a station for the quality control consisting of a camera system and storage system will be also located. The design, analysis and improvement of this manufacturing system, specially with a special focus on the communication among devices constitute the main aims of this paper. The key determining factors for the manufacturing system design are: the product, the production volume, the used machines, the disposable manpower, the disposable infrastructure and the legislative frame for the specific cases.

Abstract: In industry, grinding is commonly used as a finishing or semi-finishing operation. The surface roughness is a variable often used to describe the quality of the overall grinding system. However, the traverse and longitudinal waviness are produced by the random nature of the grinding process and by machine vibration in surface. This paper presents an adaptive fuzzy sliding mode control (AFSMC) to improve surface roughness in inner hole machining using diamond grinding bar. The experimental results show that the AFSMC can reduce surface roughness (Ra).

Abstract: In this contribution is presented the new idea of another approach and application of designed and verified assembly station that can be used for disassembly process. Automated assembly station with Cartesian industrial robot is especially designed for assembly of specific products. New approach consists in the fact that such equipment can be used for disassembly of assembled products after lifecycle. This solution can be used where it can be readjusted assembly station by proposing of particular disassembly equipment that supports the disassembly process. The paper deals with the analysis of automated assembly station design methodology and with proposals for concrete actions that need to be made to the assembly station may to change to a device designed for disassembly process. This problematic solves a development of the assembly and disassembly station with respect to lifecycle management of the assembly product and also assembly system with Cartesian robot. The main idea of the development of such a device is the use of the same Cartesian industrial robot, material supply devices, assembly and disassembly units in one workplace with different application. Result of design methodology is the verification and proposition of real automated assembly and disassembly workplace with Cartesian robot for known verified model of assembled actuator.

Abstract: According to the test requirements of elevator safety devices, the electric control system of elevator tower was designed and developed. The control system was divided into four layers: management layer, control layer, driving layer and execution layer. The Siemens S7-300 was used as the logic controller. The inverter VS-616G5 was used as the driving component. To implement close loop control, the PG card was used to receive the feedback signals send by encoder. Three software modules were developed and each module is corresponding to the kind of test.

Abstract: This paper researches on the control system for wind power generation of DFIG (Doubly Fed Induction Generator). DSP TMS320F28335 was used as the core CPU of the control system, which can meet the requirement of high precision and real time. An embedded real-time operation system (RTOS) was transplanted into TMS320F28335 and some function blocks in common use were added into the RTOS. The human-machine interface of the control system was programmed with LabVIEW, which perform the control function and can process the data came from the control system. By using this control system, many control arithmetic of wind power generation of DFIG can be tested in the laboratory.