Papers by Author: Ping Yang

Abstract: Based on the continuity equation and the motion equation of fluid dynamics, a mathematical model of high pressure transients in water hydraulic pipeline is presented. In the model, the friction item is consist of steady friction item and dynamic friction item, using the Darcy-Weisbach equation to solve steady viscous friction item and using four exponential terms instead of weighting function to solve dynamic friction item. By finite difference method accompanied with Matlab/Simulink, an example of high pressure turbulent flow in water hydraulic pipeline is configured so as to simulate the dynamic characteristics of pressure transients. The comparison between the observed result and the simulation result shows the mathematical model of high pressure transients in water hydraulic pipeline with turbulent flow is reasonable.

Abstract: In order to meet the needs of speed measurement for rotation system, a rotation sensor which based on the principle of Anisotropic Magnetoresistive Effect was designed in this paper. This paper presents the principle, detailed hardware circuit, frequency characteristics of the sensor, as well as the valid detection distance. The sensor used MR elements as the sensing element. It turned the change of the magnetic gear’s rotation speed into the change of the circuit’s output signal and ultimately achieved contactless rotation measurement of the magnetic gear. The hardware circuit of the sensor includes five parts: signal collection, impedance matching, signal amplification, digitalization processing and signal output. The tests show that its operating frequency ranges from 2 Hz to 6 KHz.

Abstract: According to the durability test results of pen cylinders, including failure modes and fatigue life data, life distribution of pen cylinder is studied. The parameters of Weibull distribution of pen cylinder are estimated by least square method. Using Weibull distribution test, the goodness-of-fit test of the pen cylinder life distribution is carried out. Results of goodness-of-fit test show fatigue life distribution of pen cylinder complies with Weibull distribution with two parameters.

Abstract: With the rapid development of the micro projector, the problems of its power consumption and heat dissipation have been increasingly serious. The thermal design can improve its reliability and cut costs at the design stage. This article selects DLP built-in micro projector provided by TI Company to analyze, uses thermal analysis software Flotherm to get the temperature distribution and temperature curves of the measuring points in the steady state, then compares the simulation results of the cooling optimization with the numerical analysis, which reduces the temperatures of thermal sources and shells. The conclusion supplies new theoretical basis on the development of mobile phones integrated with the projection function.

Abstract: A method was proposed based on principle of EKF (extended Kalman Filter) state estimation to improve the localization precision of differential drive mobile robot. The robot position was estimated by Multisensor fusion of Odometer and laser, which kinematics model, the robot sensor perception model and the sensor error model were presented. The models were introduced into the state estimation and covariance matrix update equation of EKF with match convergence condition and nonlinear error correction covariance matrix.The specific iteration equation was acquired.The simulation results demonstrate the approach of modeling and fusion is accurate and validity.

Abstract: According to the current requirements of bending fatigue test for flexible electronics, a bending fatigue machine based on SCM (single chip Microcomputer) has been designed. using stepper motor driving screw nut body as loading mechanism, improve the accuracy of the structure effectively by gaps eliminator, and achieve the requirement of precision control by using fraction driving technology in the motor control. Photoelectric counter and electrical signals detection circuit have also been designed to achieve unattended function. This design plays an important role in the following testing process.

Abstract: As a type of solid state switch, MR (magnetoresistive) sensor detects the air cylinder piston’s position in pneumatic control system. The construction and working principle of the air cylinder with MR sensor are introduced. Using 2-D magnetic field finite element analysis (FEA) method, the magnetic field distribution of air cylinder with piston motion is analyzed. Simulation results are given. The magnetic flux density characteristics are compared between piston wear or not.

Abstract: As a necessary component in pneumatic muscle, minimum switch and minimum mechanical hand, pen cylinder used as prime actuator possesses the characteristics of high speed actuation possible, easy installation, improved wear resistance and so on. The construction and working principle of the pen cylinder are introduced. Using 3-D stress field finite element analysis (FEA) method, the stress field distribution of pen cylinder with preload in mounting nut is analyzed. Simulation results are presented. The stress characteristics are compared between different preload in mounting nut and thickness of mounting bracket.