Applied Mechanics and Materials Vols. 16-19

Abstract: The performance of solenoid valve is directly related to the security and reliability of industrial system. This paper presents the design of the automatic test platform for solenoid valve. The architecture of the hydraulic subsystem and the control model of providing precise pressure for testing solenoid valve were built up. A self-adaptive fuzzy PID controller, which can dynamically modify the controller’s parameters by using fuzzy rules presented in this paper, was designed with considering the dynamic characteristics of hydraulic system. Simulation results show that the self-adaptive fuzzy PID controller, which compared with conventional PID controller, can obtain better dynamic performance and fast response.

Abstract: In this paper, Data model used in intelligent CNC system based on STEP-NC is presented. A multi-agent architecture of the intelligent CNC system based on STEP-NC is proposed. The architecture consists of fourteen functional agents, such as interpreter agent, process planning agent, simulation agent, tool path planning agent, monitoring agent, expert system agent, etc. Some key technologies to implement the intelligent control including simulation, online inspection and expert system are discussed detailed. As a result, the architecture and key technologies proposed in this paper will aid the development work of the intelligent STEP-NC system.

Abstract: Aim at the problem of work condition monitoring in high speed NC processing, a new method is proposed based on video analysis technology. It puts forward a segmentation model with maximum a posteriori and Markov random field for NC processing image sequence. Moreover, the best segmentation is obtained by optimization immunity algorithm to monitor tool and work piece effectively. The experiment shows that this method can achieve accurate and real time monitoring and demonstrate the validity and robust of the solution for barrier work piece.

Abstract: Focusing on the problem of NURBS curve interpolation in high speed manufacture, a new trajectory planning algorithm, which is suitable for chord error closed loop controlled interpolator is proposed. This tragjectory can determine accelerating, decelerating or maintenance last velocity in the next period via judging the braking distance. By the way of testing different calculating time under different CPU core, the real-time characteristic is validated. The simulation shows that chord error closed loop interpolator can automatically adjust the velocity to satisfying the precision demand, through calculating the curvature. In addition, it can assure that the maximal velocity and the acceleration were equal to the referenced parameters and machine runs with the dynamic characteristic of operator set completely.

Abstract: Based on the analysis of the compressed airflow within air splicer, the simulation of the splicing cavity was performed by using FLUENT and the air fluid field distributions of the aqueduct bodies with various shapes were obtained. The influence of the splicing cavity shape on yarn splicing quality was then analyzed and the satisfying splicing cavity shape was determined.

Abstract: MIMO (mult-input multi-output) networked control systems (NCSs) with multiple packet transmission is considered. The network-induced delay is assumed to be time-varying and less than one sampling period. Suppose the data of sensor node is part of system outputs and is transferred with static scheduling strategy, then the NCS is modeled as uncertain periodic system. The uncertain periodic system theory is used for the stability sufficient condition. Then a control design approach is presented via bilinear matrix inequalities (BMIs) method. The simulation result shows the effectiveness of the proposed approach.

Abstract: The concept of agent and multi-agent was introduced. The agent structure, negotiation strategies, and the negotiation mechanism were also researched. Based multi-agent, an automated negotiation method for bilateral contracts is proposed, which can efficiently carry out multilateral negotiations with multi-attributes in distributed environments. This framework supports efficiently multilateral negotiation. In the end, the negotiation is conducted and demonstrated that multi-agent can improve negotiation efficiency by saving negotiation time and cost.

Abstract: Battlefield weather environment can’t be collected automatically in the existing artillery command automation system, and the response speed of this system is affected seriously. So, firstly, the new-style wind speed, wind direction, temperature and humidity sensor are used to convert these weather parameters into frequency, gray code, voltage. Then the PIC16C73 chip is adopted to translate the output such as frequency and voltage into binary code which is identified easily by computer. The gray code is input into computer directly, and be translated into azimuth by programming. Finally, GAL20V8 and tri-state buffer 74HC573 are used to connect the four kind weather parameters with computer respectively through different port. The automatic collection and processing of battlefield weather environment is realized, and real time and accurate information source for command automation is provided.

Abstract: In this paper, WLAN is used to design tower crane fleet of wireless communication systems, through several performance tests to obtain a low-cost wireless bridge and actual operating parameters. The theory of computation and analysis of the environment is used to sum up focusing problem with setting up the tower crane fleet WLAN system. The results create a new direction for tower crane fleet information management.

Abstract: An experimental programme of cyclic mechanical testing of a 316 stainless steel, at temperatures up to 600°C, under isothermal conditions, for the identification of material constitutive constants, has been carried out using a thermo-mechanical fatigue (TMF) test machine with induction coil heating. The constitutive model adopted is a modified Chaboche unified viscoplasticity model, which can deal with both cyclic effects, such as combined isotropic and kinematic hardening, and rate-dependent effects, associated with viscoplasticity. The characterisation of 316 stainless steel is presented and compared to results from cyclic isothermal tests. A least squares optimisation algorithm has been developed and implemented for determining the material constants in order to further improve the general fit of the model to experimental data, using the initially obtained material constants as the starting point in this optimisation process. The model predictions using both the initial and optimised material constants are compared to experimental data.