Advanced Materials Research Vols. 433-440

Abstract: In mine power systems, false operation and failure operation of relays in parallel supply lines often take place when single phase grounding fault occurs. A novel method based on phase-to-phase current difference is proposed as line selection criterion in this paper. The method builds on that the phase-to-phase current difference based on fault phase in fault line is equal to the grounding fault current while the phase-to-phase current difference based on fault phase in sound lines is equal to zero. Thus the fault line was selected by the biggest phase-to-phase current difference of the lines. The simulation results using PSCAD and experiment results show that the method has a high accuracy and a great ability of anti-disturbance. It is quite effective when single-phase-to-earth fault occurs in one of the parallel supply lines. It also applies to any distribution system with different grounding patterns and won’t be affected by the value of grounding resistance or the degree of fault phase.

Abstract: The paper revolves around the design of large and medium-size water supply system in which the adjustable modifying factor PID fuzzy control algorithm is adopted. The design offers a solution which is targeted at the closed-loop control by analysis mathematical model is not efficiently achievable, because of the complicated water pipelines and numerous curves, as well as the fact that the objects to be controlled are characterized by their high order, big lagging, close coupling, non-linear and time-varying parameters. The design can enhance the stability and reliability of the frequency control water supply system.

Abstract: Product after-sales use and maintenance phase is the longest and most important part in the product life cycle stage. It is researched after-sales process management of product use and maintenance phase with learning from the theory and experience of contemporary technology and process management of the product manufacturing phase. It is put forward that is a proposal of after-sales process planning of the product use and maintenance. And a JSP-based computer-aided system is researched and designed which is about railway transportation equipments after-sales process.

Abstract: In this paper trajectory tracking control problem for nonholonomic wheeled mobile robots with the actuator dynamics being considered is studied. On the basis of rotation error transformation and backstepping technique, tracking control law designed for kinematic model is backstepped into dynamic model and furthermore actuator dynamics is involved. Closed-loop stability is guaranteed by Lyapunov theory and Routh-Hurwitz Criterion. Finally simulation results for tracking typical trajectory are presented.

Abstract: Well pattern is the most important affecting factor to the ultimate recovery for an oilfield development. Many researches are reported on areal well pattern, which is widely used in conventional reservoirs development such as low permeability reservoirs, heavy oil reservoirs, multi-layer sandstone reservoirs, etc. In this paper, according to the geological characteristics of fractured buried hill reservoir of Liaohe Oilfield, we firstly present the concept of stereoscopic well patterns and compare it with common areal water flooding. By using numerical reservoir simulation method, we design and optimize the parameters of 5-spot stereoscopic horizontal well patterns, including payzone thickness and horizontal well length under different anisotropic factors of fracture permeability. This can be successfully applied on the development of MM block fractured buried hill reservoir of Liaohe Oilfield.

Abstract: Aiming to solve the problems of inaccuracy in temperature control and the slow reaction in condensing system in the automated distillation analyzer, an approach which combining electrical fan and thermoelectric cooler was put forward, using STM32 as the control unit; accurate temperature control during the distillation process was realized, data collection and processing can be completed by the control unit, and the wireless module can accomplish communication and control the analyzer under the instructions of computer. With this temperature control method, the automation and test accuracy of distillation analyzer can be enhanced, thus ensuring better ratio of performance-to-price and control performance.

Abstract: The propagation of scattering Lamb wave in plate was simulated using transient dynamic analysis in ANSYS. In order to extract the characteristic information of received signal for damage identification, the short time Fourier transform based on time-frequency analysis was utilized, and then the energy distribution and envelop of received signal were obtained. Based on the displacement contour of simulation and energy distribution, the propagation of scattering wave in plate with a through hole was examined. Also, a mathematic relationship between damage location and scattering signal was developed, with the help of wave propagation path through actuator, damage and sensor. A nonlinear optimization method was applied on the mathematic relationship to obtain the damage location. The damage identification method using scattering Lamb wave was therefore established.

Abstract: It’s very difficult to get high precision measuring result using contact torquemeter because of very low signal-to-noise ratio. To overcome this defect, a wireless torque measuring system is designed based on CC2500. This system uses strain gauge torque sensor to measure the surface principal stress of the transmission shaft, and get the maximum shearing stress, and then the torque that the transmission shaft bears. The weak output signal of torque sensor is magnified by the instrumentation amplifier AD623, and sent to the analog-to-digital convertor. These digital data are transmited to the portable receiving terminal by the wireless transceiver chip CC2500. The dynamic wireless torque measurement is realized by this system.

Abstract: This paper mainly introduces the mechanical structure and parameters of Chinese massage robot, establishes coordinate system for the whole structure and on this base, establishes equations of motion for manipulator by D-H method. Then this paper makes a planning for trajectory of Palm kneading which is one of ten massage techniques, realizes it using interpolation method, and takes a simulation to the trajectory by MATLAB software at the end.

Abstract: A new method, triboelectricity and ultrasonic, for the soot mass flow measurement is developed. The direct rod-shaped sensor is used to measuring the triboelectricity charge and the ring sensor is used to measuring the electrostatic induction charge. The pure-triboelectricity can be figured out and the pure-triboelectricity is eliminated the influence of the electrostatic induction. Through the numerical simulation, the proportion between the electrostatic induction charge and the electrostatic induction charge is presented. The gas flowrate is measured by the ultrasonic. The soot mass flow can be figured out through the pure-triboelectricity and the gas velocity. Additionally, the sample calibration equipment based on the pure-triboelectricity and ultrasonic method is also introduced. Experimental results show the method can on-line measure the soot mass flow.