Applied Mechanics and Materials Vols. 687-691

Abstract: In order to improve the stability of steam turbine under large disturbance, the controller of cement waste heat power generation valve was designed by using exponential terminal sliding mode variable structure control method. In this paper, taking a single machine infinite bus power system as an example, established mathematical model of waste heat generator valve system, and designed the valve controller of synchronous generator based on the exponential terminal sliding mode variable structure control theory. Then, valve control simulation model was set up and simulation experiment was performed by MATLAB. Finally, verify the effectiveness of the scheme by comparison analysis. Simulation results show that the controller can effectively improve the transient stability of power system and the dynamic quality.

Abstract: Thin-walled aluminum alloy parts are widely used in the aviation industry. In order to predict the deformation of milling aluminum alloy 7075-T7451 thin-walled parts, a deformation prediction method based on BP artificial neural network is presented. Firstly, the orthogonal experiment is designed to acquire the experimental data. Secondly, the BP neural network model of deformation prediction based on the experimental data is established. The comparison of the simulated values with the experimental results is performed to validate the proposed model. Lastly, the result shows that the proposed deformation prediction model is reasonable and can be used to predict the milling deformation.

Abstract: The hydraulic system of radiator fin blanking machine plays a leading role in the radiator fin production. Its performance directly affects the efficiency and quality of product line. The hydraulic system of blanking machine for radiator was composed of blanking circuit and support circuit. The hydraulic system realizes the cutting action using the reciprocating movement of the hydraulic cylinder. The hydraulic system simulation model was built by the simulation software of AMESim in this paper. Using the simulation model, the simulation analysis of the dynamic characteristics of hydraulic system were completed. The hydraulic system has been through the debugging and put into production, running in good condition.

Abstract: This paper introduces the vector control of permanent magnet synchronous motor (PMSM), and proposes the control strategy according to the characteristics of the electric vehicles. The dynamics equation is obtained based on the analysis of the power system of electric vehicles, and the control scheme for PMSM is proposed. In the environment of MATLAB/SIMULINK software, the model of PMSM vector control and the electric vehicles drive system are established and analyzed.

Abstract: Intermediate stage build of Multi-station progressive die is to get intermediate configuration of every station and blank by unfolding product configuration reversely. It needs complicated hand computation and drawing to design intermediate stage with traditional method. In this paper, NX PDW module is used to finish the work. According to the shape of sheet metal, parts are simply classified into three types, and for different type of sheet metal part, different method to unfold the product configuration is discussed. The process of building intermediate stage with PDW is intuitive, timesaving, and also easy to modify.

Abstract: Structure characteristics and cavitations principle of precise dibbler are elaborate, and the mathematical model of the motion trajectory of the dibbler and parametric equations of punching contours are also established in this work. On the basis of parametric equation between punch length and wheel parameter, the effect of dibbler’s radius、fixed duckbill inclination angle 、flexible duckbill inclination angle and the slip ratio to punch length are analyzed, meanwhile in combination of field testing results the effect of wheel parameter toward cavitations size are analyzed in detail. The research results will provide reference for optimal design of the punching planter and for the research and development of new type of sowing wheel.

Abstract: In order to improve the working life of engine blade and delay the crack initiation and propagation, the shot peening strengthening treatment is usually used to.This article discusses the significance and necessity of the engine blade after shot peening and introduces shot peening strengthening process parameters to the engine blade, maily explains the equipment for engine blade shot peening strengthening, and summarizes applications of engine blade of shot peening strengthening equipment.

Abstract: With the development of die industry, multi-position progressive die is used wildly. The process rate allocation of each punching process is very important during the whole cartridge case forming. This paper shows a key point to the theoretical calculation of process rate allocation of cutting cupping, first cite-longing and second cite-longing, and these theoretical formulas can provide a reference for future researchers.

Abstract: Polygon effect is the inherent characteristics of chain drive system, and also the main factor which restricts the transmission performance of the system. In this article a structure related to a slide constraint chain drive is presented and optimized by means of MATLAB optimization toolbox. Based on polygon effect analysis, a compensation method is proposed and verified by trajectory simulation. Simulation results show that the compensation method can effectively reduce the polygon effect of chain drive and improve the transmission performance of the chain drive system.

Abstract: In order to make the biped robot realize the global stability control, this paper adopts the sub-sectional control strategy. According to the structure of the robot and the stability of the walking state, the range of each state domain is divided. Based on this we design the controller of each domain. In the unstable section the nonlinear fitting control based on the nonlinear observer compensation is adopted; in the controllable and stable section the energy shaping control is adopted; in the stable convergence section the passive control is adopted. The simulation results show that the sub-sectional control can increase the speed of the system convergence and improve the robustness of the system.