Applied Mechanics and Materials Vols. 687-691

Abstract: How to control aerodynamic noise of high speed motor train, this paper starts from the basic theory of hydrodynamics and acoustics, it adopts method of numerical simulation and applies Fluent and VirtuaUab Acousticsand software to make study on characteristics of aerodynamic noise for high speed motor train, the test results indicates that in the stable flow distribution, the baric gradient is relatively larger when its surface pressure is in area with large change in curve curvature, when it is in the area with even curve change, the baric gradient is relatively smaller. In different gradient, the train head, the maximum pressure and the maximum negative pressure ratio of air-conditioner air deflector predicate are in proportion to the square of train speed.

Abstract: The fault diagnosis of unmanned aerial vehicle (UAV) flight control system is an important research of UAV in health management. The sensor is the link which easiest to have problems of the flight control system. Making timely and accurate prediction of its faults is particularly important. A strong tracking Kalman Filter method for the sensor fault diagnosis of UAV flight control system was presented in this paper. The parameters of the system were extended to the state variables, the sensor fault observer was constructed, and the joint estimation of states and parameters of flight control system were gotten. The method can be used to real-time estimate the unmeasured states and time-varying parameters. The results of simulation experiments show that the method has a good real-time and accuracy in the sensor fault diagnosis of flight control system.

Abstract: As the mobile with large screen easily fall damage, in this paper, a finite element model of the mobile phone was built and drop simulation analysis based on ANSYS/LS-DYNA software. The impact force effects on the phone shell, LCD, touch and battery components were studied. The corresponding stress and strain distribution and the acceleration and dynamic characteristics were solved and the dangerous area of the mobile phone was found. Finally the corresponding optimization proposal was put forward. Provide reference for the study and optimization design of structure strength for this type of products.

Abstract: Unlike human beings, a robot will fall without a sufficient walking foot-ground clearance, which is essential to a success walking. However, to obtain less calculating time and simpler analysis, foot scuffing is ignored in most studies during numerical simulations of passive dynamic walkers which can walk down a gentle slope and are actuated only by their own gravity. So this paper initials a study on the effects of a passive dynamic walker’s mechanical parameters on foot-ground clearance and the results can be used to make a further parameters optimization based on walking stability analysis. A passive dynamic walking model with a hip joint, knee joints, ankle joints and an upper body and a prototype were built and numerical simulations were implemented to analyze the effects of mechanical parameters on foot-ground clearance. Finally, the results were validated in prototype experiments.

Abstract: The method of dual sensors closed-loop control is designed for the flat panel control system base on free pendulum.With this method, the angle of the free pendulum is detected firstly by adopting incremental photoelectric encoder,and then with the free swing angle as the set-point,the real time rotation angle feedback of the flat panel is detected by the angle sensor to form closed-loop control. The test results shows that this method well accomplishes the detection function,and implements high precise control.

Abstract: The author introduced the method that using the ANSYS Workbench finite element analysis software to carry out the optimization of pressure vessel. According to GB150-2011, Pressure vessel, and its empirical formula, we can find that conventional design method biased in favor of security, which cause the waste of material and increased cost. Carrying out the finite element analysis using ANSYS Workbench, we can do modification and optimization to the pressure vessel design.

Abstract: Successfully developed of high-speed SCARA robot provides the possibility for fast handling. After analyzed the mechanical structure of SCARA robot, the kinematics equations were built to analyze forward and inverse kinematics problems based on modified D-H coordinate system theory. The trajectory planning was achieved by using the cubic polynomial interpolation method in joint space over the path points combined with motion parameters, the kinematics and trajectory planning were simulated by using matlab simulation platform. Simulation results show that robot parameter design is reasonable and the trajectory planning by interpolation calculation in joint space is feasible.

Abstract: In order to reducing the worker's labor intensity in tobacco sewing, a new machine adoption with single thread sewing technology was developed. Through analyzing the existing problems in sewing machine and the tobacco damage situation, using drawing method, analytic method and other methods, the shape of the sewing component, hook line components and other mating parts were designed. The results show that the machine has the advantages of simple structure, controllable sewing speed, adjustable leaf thickness and quantity. And the tobacco leaf damage rate is low. The comprehensive efficiency in tobacco leaf knitting with this machine is four times higher than that with hand knitting. Its application prospect is considerable.

Abstract: For dual synchronous brush-less DC motor control system’s operation problems due to load disturbance caused by poor synchronization performance, this article establish a mathematical model of brush-less DC motors and synchronous control system, based on the basis of comparison of various control methods and control synchronization control, use VUFPID control algorithm to compensate for the bias adjustable dual brush-less DC motor control program, and compare with conventional PID and fuzzy PID algorithm. Through the simulation results and conclusions show that VUFPID control algorithm can improve the control system coupled deviation synchronization accuracy, superior to conventional PID and fuzzy PID algorithm system.

Abstract: Aimed at the goal of improving the quality and the efficiency of welding for T-type welding seam, This paper put forward a method to track the seam by using the vision sensor. Machine tool main motion trajectory is generated from the numerical model of the parts. The position of two welding torches are adjusted independently based on the machine tool main motion trajectory to ensure the welding precision. Two sets of adjusting mechanism are needed for T-type welding seam. The vision sensor measure the seam and pass the deviation signal to the CNC system. The CNC system adjust the position of the welding torch installed on the cross slide table to reach the goal of seam tracking and dual-beam laser welding for T-type welding seam. Practice shows that this system for T-type welding seam dual-beam laser welding is easy to operate and can improve the quality and the efficiency.