Advanced Materials Research Vols. 139-141

Abstract: In this paper the average run length is adopted as the tool to describe the performance of control charts. The respective methods for calculating the average run length of the modified Shewhart control chart and the Shewhart residual control chart for 2-order autoregressive process are derived and shown in detail. By the proposed approach some numerical results of average run lengths of both Shewhart type charts are formulated and discussed. We analyze and compare that the influence of the correlation coefficients of the 2-order autoregressive process on the performance of both charts based on the estimated data. Several clear and main points of the issue are summed up. Lastly, we give some recommendations for the choice of both Shewhart type control schemes.

Abstract: Relative to gear shaping and gear hob, using gear slotting produces herringbone gear which is used in nuclear power turbine speed redactor has more obvious technical and economic benefits, but profile angle error of slotting cutter causes profile error and base pitch deviation of herringbone gear. It will result in high-frequency noise which damages the tactical and technical performance of warship. By analyzed the wire cutting system of rack cutter used in MAAG type gear machining for herringbone gear, the mathematical model of error prediction for rack cutter profile angle was founded. On the base of model of error prediction, the principle of error control and the method of revision control are presented. Finally, the example of prediction and control is provided.

Abstract: Based on the analysis of the disadvantages of shoe last making with 3-axis shoe last NC machine, this paper presents a novel solution for last making with 5-axis shoe last NC machine, introduces the working principles, motions, components and implementation of 5-axis shoe last NC machine in detail. A key feature of the machine is that it can produce complete lasts in one working process, avoiding milling the toe and heel with final manual finishing operations. This paper proposes an algorithm of the tool path generation of the machine. By the grid data of the last surfaces and spiral interpolation, we can obtain the cutter contact points and cutter location points and then deduce the formula of solving each component motion in the machining. A model machine developed by the presented solution demonstrates the improved machining efficiency and high quality of shoe last.

Abstract: Assembly performance test bed is an indispensable equipment in the development and production of air compressor assembly. The test bed studied is a mechanical, electronic and hydraulic integrated equipment and its measuring and controlling system mainly consist of computer system, process channel, control object and measuring and controlling software. Guided by the “soft hardware” design conception, two “soft” subsystems was adopted in a one-level computer system to replace the generally adopted two-level “hard” system consisting of measuring and controlling subsystem and management subsystem. This improvement allows the more applications of integrated sensor and intelligent controller, resulting in a simpler hardware and greater openness. The practice indicated that, with rapid parameter adjustment, accurate measuring, large testing scope and high automation, the system meets all the technical indexes of test requirement.

Abstract: Implicit cost (PONC) which was produced by nonconformance in manufacturing process bring a large number of loss to the enterprise. For the data of PONC during manufacturing process is difficult to collect, and difficult to calculate costing of scrap and rework PONC, the included projects and the calculation method of Price of Nonconformance is proposed and analyzed to quantify scrap and rework PONC. The calculation method can be programmed and implemented by means of C# language in the paper, and the working procedure which the Price of Nonconformance is beyond the standard is analyzed and improved. The results of example analysis and verification show the calculation method of PONC is effective way to improve the efficiency of cost management, reduce quality cost, improve product quality and increase the economic efficiency of enterprise.

Abstract: The Screw Down System (SDS) is a typical hydraulic servo control system. It is the key actuator of cold rolling mill. The dynamic performance of SDS has a significant effect on the accuracy of thickness. Hydraulic servo control system is not always optimal and stable due to highly nonlinear and parameter uncertainties. In this paper, the most important nonlinear relating flow and pressure is analyzed. A nonlinear self-adaptive compensation method is designed. Modeling and simulating the hydraulic servo control system of SDS using this method, the numerical simulation results show that the maximum overshoot and static error of the compensated system are more less than that of without nonlinear compensation. The overshoot of the compensated system is less than 10% when the cold strip is rolling. So the thickness tolerance of the cold strip can be guaranteed easily. This self- adaptive compensation method can be used to other hydraulic servo control systems.

Abstract: In order to improve the flatness of cold rolled strips, strategies of closed loop feedback flatness control and rolling force feed forward control were established respectively, based on actuator efficiency factors. As the basis of flatness control system, efficiencies of flatness actuators provide a quantitative description to the law of flatness control. For the purpose of obtaining accurate efficiency factors matrixes of actuators, a self-learning model of actuator efficiency factors was established. The precision of actuator efficiency factors could be improved continuously by correlative measurement flatness data inputs. Meanwhile, the self-learning model of actuator efficiency factors permits the application of this flatness control for all possible types of actuators and every stand type. The developed flatness control system has been applied to a 1250mm single stand 6-H reversible UCM cold mill. Applications show that the flatness control system based on actuator efficiency factors is capable to obtain good flatness.

Abstract: Turret feeding servo system is the connecting link of a servo motor and a linear motion unit. Studying the static performance and the dynamic performance of the feeding servo system plays a key role in precision finishing and it also is the key technology to realize the high precise CNC lathe. This article builds several mathematical models for the driving part, the speed governing part, the mechanical transmitting part and the feeding part of the feeding servo system using permanent magnet synchronous motor (PMSM) and then simulates the system with Simulink so as to verify the mathematical models; optimize the servo system by combining the traditional PID control with the fuzzy control and finally, compare and analyze the system performances under several control methods, which may provide references for designing a feeding servo system.

Abstract: This paper describes a configuration method of kiln outlet production line in which a new integrated control system PCS7 of Siemens is used. From the raw feeding to the clinker storage, and from measurement unit at the bottom to management at the upper system, the configuration realizes a transversal and vertical integration and automatic control of the productive process. The operational principle of the kiln, burning process of raw power, pulverized coal and hot airflow in the kiln and cooling procedures and transportation of clinker in grate cooler are all analysed at length. The control requirements, influencing factors and controlling methods of the secondary air flow, which is the most important factor in all process parameters, are analysed in detail, and the control loops of opening degree of valves and the speed of waste gas fan are designed to improve and stabilize the temperature of secondary air flow.

Abstract: Ordinarily, water fire monitor extinguishing systems are applied to protect large space places from fire. To intellectualize them and improve the water usability and extinguishing efficiency, it is necessary to realize the closed-loop control of the landing position of the water jet out from the monitors in order to let the water jet reach the fire point as fast as possible. According to the characteristics of the adjusting mechanism of fire monitors, combing with the new theoretical model for their water jet track, the closed-loop control procedure is simulated. The results show that the water jet can reach the ignition point after only several adjustments. The effective control procedure simulation paves a sound basis for the closed-loop control of the landing position of the water jet out from water fire monitors.