Advanced Materials Research Vols. 834-836

Abstract: The verification of electronic type electric energy meter is under strict reference conditions, but some special operating conditions at locale will exceed the standard scopes. In order to improve the calculation accuracy and operating reliability of electric energy meter under operating conditions, it is necessary to study the operating conditions. According to the working principle and the standard verification regulation of electronic type electric energy meter, this paper summarizes these operating conditions: low power factor, harmonic waves, dynamic impulsive load, voltage fluctuation and outside magnetic field of power frequency, then analyzes the causes of operating conditions and their influence on electronic type electric energy meter, eventually lays foundation for thorough and systematic study of electric energy meter in the operating conditions, and establishes measurement center database of operating conditions.

Abstract: A fuzzy sliding control for the motion of the robot manipulator is proposed. The quasi-sliding mode control (QSMC) was added to the fuzzy control. Therefore the system inputs and fuzzy rules can be reduced in fuzzy sliding control. Then the system will be a Single Input Single Output (SISO) system and it has only five fuzzy rules. This makes design process much more simple. The simulation results show that by employing proposed controller to the position control of a three-axis robot manipulator, the overshoot was drastically reduced. Also fast rising time and a small extent of steady-state error can be obtained.

Abstract: A novel remotely operated underwater vehicle-a hybrid remotely operated underwater vehicle (HROV) capable of working to the full ocean depth has been developed. The battery powered vehicle operates in two modes. For broad-area survey, the vehicle can operate as an autonomous underwater vehicle (AUV) capable of mapping the sea floor with sonars and cameras. For close up imaging and sampling, the vehicle can operate as a remotely operated underwater vehicle (ROV) employing a optic fiber tether for real-time telemetry of data and video to its operators on a surface ship. In order for the vehicle to achieve a certain survivability and reliability level, a self-repairing control system (SRCS) has been designed. This paper presents the two basic technologies in SRCS: fault diagnosis and isolation (FDI) and reconfigurable control. For FDI, a model-based hierarchical fault diagnosis system is designed for the HROV. Then, control strategies which reconfigure the control system at intervals according to information from the FDI system are presented. Combining the two technologies, we obtained the fundamental frame of SRCS for the HROV.

Abstract: The dissertation focuses on the limited calibration accuracy of breaker instantaneous problems,explains the reasons for calibration current error.It expounds the current amplitude error,as well as the decomposition method for non-periodic component error.Meanwhile,this dissertation proposes calibration current evaluation methods and successive approximation control methods.It demonstrates the feasibility of this method,by adopting theoretical analysis and simulation.It has been proved through practical application that the method is used to eliminate current error and enhance breaker instantaneous calibration accuracy.

Abstract: The periodic and chaotic dynamic responses of face gear transmission system considering time-varying mesh stiffness and backlash nonlinearity are studied. Firstly, a nonlinear time-varying dynamic model of face gear pair is developed and the motion equations are presented, the real accurate mesh stiffness is obtained by applying Finite element approach. Then, the dynamic equations are solved using Runge-Kutta numerical integral method and bifurcation diagrams are presented and analyzed. The stability properties of steady state responses are illustrated with Floquet multipliers and Lyapunov exponents. The results show that a process of periodic-chaotic-periodic motion exists with the dimensionless pinion rotational frequency as control parameters. The analysis can be a reference to avoid the chaotic motion and unstable periodic motion through choosing suitable rotational frequency.

Abstract: The force of ship is one of the main loads which High-Piled Wharf bears, the assignation of transverse component on each bent is the precondition of the calculation which simplified the wharf structure into plane bent. The taking value of transverse component on bent influences a lot on the result of structure calculation. Nowadays, the design of High-Piled Wharf uses the value from the distribution coefficient in the Design and Construction Code of High –Piled Wharf. The results show that the distribution coefficient taken in the code is under the precondition that considering the beam is rigid; the relative stiffness of beam and pile can influence this distribution coefficient. Considering the flexibility of the beam, the distribution coefficient of the horizontal concentrated force on transverse bents will change.

Abstract: The power loss and efficiency model of a planetary gear transmission system was built with a system modeling method. The method takes many transmission elements such as gear, planetary gear sets, hydraulic torque converter, friction disk, lubrication, sealing, bump and motor etc. into consideration and calculates non-load and load power loss for each element. The overall calculated power loss and efficiency is more accurate than the meshing power method. To make simulation more reliable it is compared with the test data. In the paper some planetary gearbox is selected and its power loss and efficiency were measured from the experiment. The power loss and efficiency of each gear of the planetary gearbox are compared and verified and corresponds well with the test data. The power loss error drop from 10% to 5% with the system method compared with meshing power method. It shows that the system method for power loss and efficiency analysis is more reliable. It provides important basis for engineers to improve design and reduces the power losses. It provides solutions to increase the planetary gear transmission efficiency and finally makes the whole vehicle lighter and the power density higher than before.

Abstract: Mechanicalmethods were employed to study the motion and force transmission performance ofa kind of connecting rod slider mechanism with a curved edge driving component.The deduction methods and the computation formulae of the slider displacement,velocity, acceleration and the executive force gain coefficient were given.Considering two cases of the driving components with straight line edge andexponential function edge, the numerical examples was computed respectively,the results show that the former one is suitable for the force transmission andcan be used in the grip design and the other one is suitable for the motiontransmission which can be used in the fast moving mechanism

Abstract: The dynamic load on drive axle housing has great significance for analyzing the strength of drive axle housing and studying the reliability life of drive axle housing, and road roughness has an important impact on dynamic load of drive axle housing. In this paper, the drive axle housing of agricultural machinery is select as the research object. Firstly, the dynamic model of the drive axle housing is established, and the vibration equation is calculated by Laplace transform and Laplace inverse transform, and then the vibration load time history is given based on the discrete data of road roughness obtained by field experiment. At last, the rainflow counting method is used to generate the load spectrum. The study has a certain reference and application value for the optimization design of drive axle housing of agricultural machinery.

Abstract: The present work assesses the structural analysis of the main lighthouse of Livornos harbor. It is made by a r.c. framework, built in the 50s as reconstruction of medieval tower similar to it. The wind and seismic actions (with and without collaboration of the masonry infill and façade) are investigated, showing the fundamental contribution of the masonry layers for a satisfactory structural response.