Applied Mechanics and Materials Vols. 128-129

Abstract: In this paper, a H_∞ control approach based on T-S fuzzy model for flexible joint robot is proposed. First, the Takagi and Sugeno (T-S) fuzzy model is applied to approximate the flexible joint robot. Then, a fuzzy controller is developed based on parallel distributed compensation principle (PDC), and H_∞ performance is employed to restrain the influence of modeling error caused by variety of stiffness. The stability conditions for the flexible joint robot control system are proposed by Lyapunov function. Finally, the simulation results are given to show the effectiveness of the proposed method.

Abstract: The structure and the principle of the electronic throttle control system (ETCS) is elaborated. The electronic throttle (ET) control model is built based on Matlab/Simulink, and the hardware-in-loop simulation on the ET model is processed. The result shows that the hardware-in-loop electronic throttle system have significant means on the automotive electronic teaching and design.

Abstract: This study focus on the stiffness analysis of a three-DOF orientation fine-tuning manipulator for segment assembly robots in shield tunneling machines. In underground space development, shield tunneling machines are widely used in subway tunnels, channel tunnels and other kinds of tunnels. As one of the key sub-devices in a shield tunneling machine, a segment assembly robot is used to automatically form the segment lining. In order to evaluate the operational capacity, an analysis of the inverse kinematics is conducted. The local performance atlas, including stiffness and dexterity, are investigated. The results show that the proposed orientation fine-tuning manipulator has good performances and it can meet the needs.

Abstract: An improved DV-HOP localization algorithm is proposed in the paper, aiming at the traditional DV-HOP localization algorithm. The improved algorithm introduces threshold M, it uses the weighted average hop distances of anchor nodes within M hops to calculate the average hop distance of unknown nodes. In addition, the positioning results are corrected in the improved algorithm. The simulation results show that the improved localization algorithm effectively improves the positioning accuracy compared with the traditional DV-HOP localization algorithm, it is an effective localization algorithm for the wireless sensor networks.

Abstract: In this paper, three kinds of FEM models, i.e., the truss element model, the beam element model and the mixed beam-solid element model are utilized to simulate the full-scale field test of transmission tower. Based on Abaqus software, the geometric and material nonlinearity of the structure is considered. Comparing the numerical results with test data, it is found that the truss element model is no longer suitable and the mixed beam-solid element model is more accurate than the beam element model. Thus, using solid element to discrete the key nodes of the tower can greatly enhance the accuracy and reliability of the numerical prediction.

Abstract: GMHPUT has a wide range of potential application in industrial. However, nonlinearity between exciting current and output displacement spoils GMHPUT’s performance. To explore the nonlinearity behaviors of GMHPUT, a nonlinear dynamic model was established. The bifurcation diagrams, phase portrait, Poincaré mapping diagrams, amplitude spectrum, Lyapunov exponent, etc. which demonstrate dynamical characteristics of the system were obtained by numerical integration. Analysis indicates: Nonlinearity of response could be improved by increasing of damping coefficient. Chaos would appear when stiffness of the system is low. At last experiments were done to verify the model. Calculation results and experimental results show a good agreement.

Abstract: Based on the structure of permanent magnet (PM) spring, composed of one fixed end magnet and one moving magnet, a nonlinear resonant electromagnetic micro-generator is designed, which is suitable for human wrist vertical shaking and can be used as an emergency power source for portable electronic products, such as cell phone. Generator model is built under the condition of resistive load, which has been solved numerically through simulation. The model is validated by the measured results and can be used for further study of generator optimization and power processing circuits. The experimental results show that the prototype could generate power as high as 50 mW under the condition of simple harmonic driving acceleration with the amplitude of 0.8 g (7.84 m/s²) and the frequency of 3.33 Hz.

Abstract: The structure of gas blower group is complex. There are many types of fault and many fault are hidden, such as axial channeling move, rotor rubbing, resonance of sliding bearing oil film, gear fault , unbalanced, misalignment .etc. The happening of these kind of fault, will affect seriously the efficiency and safety of operation of the gas blower, leading to the paralysis of the production system. Therefore, it is necessary to design an On-line fault intelligent monitoring diagnosis system for gas blower group as soon as possible. When on-line monitoring , at the same time ，the computer in the background online real-time analysis all kinds of dynamic vibration signal automatically, discriminate the operating status of these blower group, depend on consequence of all kinds of analysis , by intelligent reasoning, online real-time display fault type, the cause, site and severity. Can also be offline man-machine interactive for intelligent diagnosis precision.

Abstract: As one of the most important equipments in the power system, partial discharge (PD) affects the transformer’s properties in a long-term period and the partial discharge pattern recognition has most important sense. In the paper,3 kinds of experimental models simulating discharges were designed and model experiments were performed. Based on this, a transformer partial discharge pattern recognition system based on information fusion technology is developed. the finally experiments show that: information fusion have enough ability to recognize different types of partial discharge.

Abstract: Hard target penetration acceleration signals are non-stationary signals. In this paper use the local mean decomposition theory to analysis hard target penetration acceleration signals. Local mean decomposition can adaptively decompose any complex non-stationary signal into a number of physically meaningful instantaneous frequency components and these components could well reflect the intrinsic nature of the signals. Use local mean decomposition to separate the rigid projectile overload from hard target penetration acceleration signals. That provide reliable data to support accurately calculating the effective penetration depth, hard floors or holes through the number of target parameters on the penetration of weapons is significant. The author apply local mean decomposition algorithm in penetration acceleration signal separation and the results verify the effectiveness of the method.