Applied Mechanics and Materials Vols. 719-720

Abstract: According to the existing problems of driving equipment for belt conveyor, a novel design scheme of controlled transmission which uses hydraulic transmission system driving worm gear to control the output speed of planetary gear mechanism is proposed. The control strategy of multi-motor drive power balance which adopts master-slave structure is designed. The master driver adopts speed closed-loop control with current limiting and the slave drivers adopt power closed-loop control. The given power signal of slave pulley is decided by the master motor. The control system offers multiple communication interfaces which enable the belt conveyor to integrate in coal mine information platform and realize information resource sharing. The controlled transmission device and its power balance control system have characteristics of compact, reliable and high efficiency.

Abstract: For the problem of serial robot structure error, method of relative position correction was researched. An adaptive filtering correction method based on robot joint position feedback was proposed. The method built a robot joint adaptive filtering corrector (AFC) to correct robot joint feedback. The real spatial position of robot end-effector can be got through the forward kinematics computation with the corrected joint feedback. Thus, the robot structure error is corrected. Weights matrices of AFC were trained with relative positions between calibration points on the standard calibration module. The proposed method of relative positions correction provides a new way for serial robot structure error correction, which does not directly modify the robot kinematics design parameters, dose not need measuring equipment, and can be applied in field. The simulation results got with LabVIEW robot module show that the corrected trajectory of robot end-effector is more approaching to its true trajectory than before, which means the robot structure error is effectively corrected.Keywords: Correction; Relative position; Serial robot; Kinematics

Abstract: In this paper, 0.05 grade three-phase main control system of multi-station meter testing equipment (MTE) is presented. This design is based on the S3C2440 core board as the control core, and the software is based on Windows CE(WINCE) embedded operating system. The device is displayed and controlled by 7-inch Touch Screen. The main control system communicate with the error instrument and PC through Controller Area Network (CAN) bus, and the largest number of error instruments can connect to CAN bus is 100. The main control system communicates through RS232 bus with three-phase signal source and standard electric energy meter, through RS485 bus with programmable power amplifier. In this device, calibration of energy meters can not only through the PC software, but also use the main control system. Compared to the traditional design of the electric energy meter calibration device, the design’s the man-machine interface is more optimized, the number of electric energy meters can be test in the same time is more, faster communication, stronger anti-interference ability, and calibration is more efficiency.

Abstract: The switched mode dc-dc converters are some of the most widely used power electronics circuits because of high conversion efficiency and flexible output voltage. Many methods have been developed for the control of dc-dc converters. This paper deals with design of controller for dc-dc buck converter using various control techniques. The first two control techniques are based on classical or linear control methods i.e. PI and PID control, while the other two control technique are based on non linear control method i.e. Sliding Mode Control (SMC) and Sliding Mode Proportional Integral Derivative Control (SMC-PID). The output voltage and the inductor current of the applied control techniques are analyzed and compared in transient and steady state region. Also the robustness of the buck converter system is tested for load changes and input voltage variations. Matlab/Simulink is used for the simulations. The detailed simulation results are presented, which compare the performance of the designed controllers for various cases. The results show that the non linear control for DC/DC Buck converter proves to be more robust than linear control especially when dynamic tests are applied.

Abstract: This paper studies prognostic and health management (PHM) system for smart grid based on wireless sensor networks. The system function is analyzed firstly. Then, problems like networking hardware selection and data processing method have been discussed. The application of data fusion is discussed specially. In the end, the system platform based on a data-centric hierarchical technology architecture is designed with four layers: network configuration layer, network communication layer, platform basis layer and application layer. The research work of this paper is theoretical support for the realization of PHM for smart grid and the application of WSNs in smart grid.

Abstract: As a benchmark to assess the performance of the control loops, MV (minimum variance) has been widely used in industrial process.MV control gives the lowest achievable output variance when there is no constraint on the actuator. In this paper, it shows that MV controller is no longer optimal and the mean of the output value is non-zero when the constraint is active and the parameter of the disturbance is approaching to one. In order to achieve the lowest variance of the output value, and the mean of the output value can be approaching to zero, a new approach is proposed in this paper. The proposed method is imposing a compensation value on the constrained MV control law, meanwhile, a new performance index function is introduced. As a result, it is believed that this method is more effective to the real industrial process for systems with actuator constraints and stochastic disturbances. Simulation example demonstrates the usefulness of this method.

Abstract: The Smart Grid, acting as a powerful technique for addressing the existing challenges in the power network, has matured in recent years. Its importance has been well recognised. As the most important property of the Smart Grid, the information interactivity over the power network is a frequent topic for academia and industry. Therefore this paper introduces the main achievements of recent years associated with the communication technology and signal processing methodology based on the Smart Grid. Their pros and cons will also be summarised and analysed in detail. To be brief, the novel properties and developments of the Smart Grid, the communication techniques, and the involvement of cRIO integrating FPGA, TDMS, SQL Server, DataSocket Server and LabVIEW Electrical Power Suite will be elaborated upon.

Abstract: This paper analyzes the core values of the smart grid that is the need of significant stakeholders, the reliable and efficient electricity supply for users and running economy for power grid enterprises. Using fishbone analysis gets the main elements, which are the quality and reliability of power supply, grid structure, equipments situation, intelligence level and operation level. Due to the complexity of the evaluation system,the entire system divided into three layer levels,the target layer, the element layer and the index layer. The structure and operation of low voltage distribution grid and medium-high voltage distribution are significantly different,they separate into two systems to evaluate,it can get the evaluation index system. Compared with the traditional distribution grid evaluation system, this system is more comprehensive and systematic for evaluation the development level of the smart distribution grid,it is practically valuable for evaluation work.

Abstract: In this paper, we investigate the cluster mixed synchronization scheme in time-varying delays coupled complex dynamical networks with disturbance. Basing on the community structure of the networks, some sufficient criteria are derived to ensure cluster mixed synchronization of the network model. Particularly, unknown bounded disturbances can be conquered by the proposed control. The numerical simulations are performed to verify the effectiveness of the theoretical results

Abstract: With the increasing of resonant frequency and integration of film bulk acoustic resonator (FBAR), the electromagnetic interference (EMI) of FBAR devices appears to be extremely important. The electric fields of the common electrical model and finite element model are assumed to be quasi-static and cannot simulate the electromagnetic (EM) property. A 3-D EM model of FBAR is achieved by means of high frequency EM simulation software HFSS. A real-time simulation of EM distributed effects, EM coupling and piezoelectric effects is achieved by employing an effective permittivity in the EM model. The effects of the high frequency EM distributed effects and the EM coupling on resonant characteristics are analyzed. By optimizing the distance between FBAR and components, introducing substrate materials with different permittivity, the EM coupling is effectively reduced.