Applied Mechanics and Materials Vols. 121-126

Abstract: A camera calibration based on controlled motion sequences and homography is adopted. First condition of unique solution for constrained equation set is proofed. Then two sets three orthogonal motions are carried out for camera in manipulator, thus 6 homographic matrixes of plane are obtained at 7 view points, and thus the intrinsic parameters of camera are achieved. The experiments on real images validate our technology based on homography.

Abstract: Traffic management can improve QoS of the network, the exist well-known algorithm for the network traffic management has some problems in the sensitive degree and the network reliability, using queuing theory build up the basic M/M/1 model for the network traffic management, obtaining the network traffic forecasting ways and the stable congestion rate formula, combining the general network traffic monitor parameters, realizing the estimation and monition process for the network traffic rationally. By testing the algorithm, we know that queuing theory can optimize the network traffic, it’s convenient and simple for calculating and monitoring the network traffic properly.

Abstract: To approximate some problems with strongly discontinuous coefficients, we present the large jump asymptotic method for parabolic interface problems, focus on the derivation and proof of the asymptotic error estimates for our approximation, and show it is of order two. Numerical experiments verify the theoretical results.

Abstract: Long span mobile bridges (LSMBs) are widely used in military maneuver operations or civil rescue works across narrow gorges or rivers. Especially it is quite a difficult problem to design LSMBs of over 50 m length satisfying required safety criteria under military load class 70 (MLC 70), namely permit vehicle weight of 63.5 tons. In order to optimize a LSMB of 60 m length for both lightweight and minimum deflection under MLC 70, a multi-objective optimization process based on genetic algorithm (GA) and weighted sum method for handling multiple objectives was utilized after its validity verification with the six-member and five-node truss problem. GA in this study utilized a variable penalty function to treat design constraints and fitness function to deal with both objective and penalty functions together. Finite element structural analysis of the LSMB was done by ANSYS for the design optimization process. As the result, the optimally designed LSMB of 60 m span that meet requirements and safety criteria of a military bridging equipment design and test code has been successfully obtained.

Abstract: Human consciousness has multiple channels and not only relying on eyes. People uses touch sense to understand and feel world since it is feeling system's reaction to material because of physiological stimulation. The essay discusses on application of touch experience in graphic design and how to use touch organ sense to design graphic designing that conform with audience demand by discussing on designing concept of touch experience and researching on touch sense expression from perspective of designing psychology.

Abstract: With the development of science and technology, the quality of the product is better and better. Consequently, in the time-ended life tests, zero-failure data is of frequent occurrence． So the evaluation of the product’s life has important meaning and greatly practical value． While Bayesian estimation is a very effective method about the analysis of the product’s zero-failure data. In the paper, Bayesian estimation of failure probability of zero-failure data are take out, combined linear fitting method and the software of Matlab, the method to ascertain types of product’s life distribution is come out according to zero-failure data. Finally calculation is performed regarding to zero-failure data of a certain model engine, and ascertain the equation of the engine’s life distribution.

Abstract: This paper describes a new approach to establish the helix flute model of solid carbide end mills. Based on the theory of differential geometry and coordinate transformation, a mathematical model of the end mill helix flute will be established.The main idea of the study is to envelop the helix flute by a one-parameter surface group which consists of the cross-sectional profiles of the wheel.Then, the mathematical model will be quickly verified by MATLAB.Thus the end mill design time will be saved and the new mathematical model will be checked effectively.

Abstract: Aimed at the design of the radius of flute for solid carbide end mill, a new oblique cutting model for milling was established based on the simplified model of milling layer. Depending on this model, an equation was developed to calculate the maximum chip thickness in milling. An oblique cutting simulation via FEM(Finite Element Method) was conducted to verify the equation. The conclusion was that the result gained from the simulation was in a good agreement with the present model, so the present model is reasonable to predict the maximum chip thickness in milling and to determine the radius of the arc at the bottom of the flute.

Abstract: High velocity and stability are the development trend and inevitable requirement, but the clearance would make the stability of mechanical system deceased, especially in high speed. To the folder mechanism with clearances in high velocity, combined with the definition of sensitivity and the kinematics analysis, the kinematics sensitivity analysis model is derived by the matrix analysis method. Through the sensitivity analysis model, it can be easy to get the relationship of the design variables and the mechanism’s robustness, which provides the base to design the folder mechanism in high velocity.

Abstract: A sensorless control model based on a model reference adaptive system (MRAS) with the theory of parameter optimization for the Permanent Magnet Synchronous Motors (PMSM) servo system is presented in this paper. The model can promptly work out the speed of the rotor without any other position/speed sensor. Different from the other MRAS-based speed observers which constructed according the theory of stability customarily, by using the error between the measured phase currents of actual motors and theoretic phase currents acquired by the mathematical model of motors as the parameter to be optimized, the proposed model can gain the speed of rotor with fast response and better performance. The stability of MRAS is analyzed subsequently. In the model, only a few parameters are needed and satisfactory performance can be achieved. So this model is very simple to be used as the position/speed observer of the PMSM servo system. Finally the simulation and experimental results confirm the validity and advantage of the proposed method.