ASCS Online Fault Detection and Isolation Based on an Improved MPCA

Multi-way principal component analysis（MPCA）has received considerable attention and been widely used in process monitoring.A traditional MPCA algorithm unfolds multiple batches of historical data into a two-dimensional matrix and cut the matrix along the time axis to form subspaces.However,low efficiency of subspaces and difficult fault isolation are the common disadvantages for the principal component model.This paper presents a new subspace construction method based on kernel density estimation function that can effectively reduce the storage amount of the subspace information.The MPCA model and the knowledge base are built based on the new subspace.Then,fault detection and isolation with the squared prediction error（SPE）statistic and the Hotelling（T2）statistic are also realized in process monitoring.When a fault occurs,fault isolation based on the SPE statistic is achieved by residual contribution analysis of different variables.For fault isolation of subspace based on the T2 statistic,the relationship between the statistic indicator and state variables is constructed,and the constraint conditions are presented to check the validity of fault isolation.Then,to improve the robustness of fault isolation to unexpected disturbances,the statistic method is adopted to set the relation between single subspace and multiple subspaces to increase the corrective rate of fault isolation.Finally fault detection and isolation based on the improved MPCA is used to monitor the automatic shift control system（ASCS）to prove the correctness and effectiveness of the algorithm.The research proposes a new subspace construction method to reduce the required storage capacity and to prove the robustness of the principal component model,and sets the relationship between the state variables and fault detection indicators for fault isolation.     

MODELING AND ROBUST DESIGN OF REMANUFACTURING LOGISTICS NETWORKS BASED ON DESIGN OF EXPERIMENT

The uncertainty of time, quantity and quality of recycling products leads to the bad stability and flexibility of remanufacturing logistics networks, and general design only covered the minimizing logistics cost, thus, robust design is presented here to solve the uncertainty. The mathematical model of remanufacturing logistics networks is built based on stochastic distribution of uncontrollable factors, and robust objectives are presented. The integration of mathematical simulation and design of experiment method is performed to do sensitive analysis. The influence of each factor and level on the system is investigated, and the main factors and optimum combination are studied. The numbers of factors, level of each factor and design process of experiment are investigated as well. Finally, the process of robust design based on design of experiment is demonstrated by a detailed example.     

NONLINEAR DATA RECONCILIATION METHOD BASED ON KERNEL PRINCIPAL COMPONENT ANALYSIS

In the industrial process situation, principal component analysis (PCA) is a general method in data reconciliation. However, PCA sometime is unfeasible to nonlinear feature analysis and limited in application to nonlinear industrial process. Kernel PCA (KPCA) is extension of PCA and can be used for nonlinear feature analysis. A nonlinear data reconciliation method based on KPCA is proposed. The basic idea of this method is that firstly original data are mapped to high dimensional feature space by nonlinear function, and PCA is implemented in the feature space. Then nonlinear feature analysis is implemented and data are reconstructed by using the kernel. The data reconciliation method based on KPCA is applied to ternary distillation column. Simulation results show that this method can filter the noise in measurements of nonlinear process and reconciliated data can represent the true information of nonlinear process.     

轮胎成型机的技术革新方案

Energy-saving technology of injection molding machine is the service for reducing costs of injection molding products and enhancing performance of injection molding products. So energy-saving technology must meet the requirements of injection molding for products, rather than the injection molding of products to suit energy-saving property of injection molding machine. The energy-saving technology should be looked on scientifically and dialectically, there are a variety of energy-saving technologies on injection-molding machine, and each has its own applied limitations. Only both of the energy-saving technology and injection molding are combined together to form an integrated new technology, the advantages of energy-saving technology applied on injection molding machine can be brought into play. If we take energy-saving technology as a pure energy conservation to promote, it has not way out, so it should choose appropriate energy- saving technology according to the requirements of injection molding.     

Four Materials Co-injection Molding Machine

Guangdong Borch Machinery Co., Ltd. launched their latest four materials injection molding machine （four colors injection molding machine） recently. This machine is based on the modular design and is designed by the mode of flexible combination. The structure is to add a set of horizontal plasticizing system which is installed in the back of the main plasticizing system and is a 13° bevel with it based on the original three materials co-injection molding machine.[第一段]     

Brief introduction of current status domestic blow moulding machine

Blow molding is a commonly used method which manufacture of hollow thermoplastic products, the main products are film blowing machine and hollow container. Blow molding machine can be heated so that made pre-molding plastics products to plasticate , and then blown into molding, this method is mainly used for high-speed, high-volume production of PET and BOPP bottles, that is two-step process; blow molding and injection molding can also be combined into all-inones injection stretch blow machine, which is a commonly used methods in the production of PET container; blow molding process can also be combined with the extrusion process, extrusion blow molding equipment adapt to a wider range, which can produce the product more enrich, including multi-layer compound films and various types of polyolefin hollow container widely used in foodstaff, pharmaceutical and cosmetics industries.     

PERFORMANCE EVALUATION METHOD FOR BUSINESS PROCESS OF MACHINERY MANUFACTURER BASED ON DEA/AHP HYBRID MODEL

A set of indices for performance evaluation for business processes with multiple inputs and multiple outputs is proposed, which are found in machinery manufacturers. Based on the traditional methods of data envelopment analysis (DEA) and analytical hierarchical process (AHP), a hybrid model called DEA/AHP model is proposed to deal with the evaluation of business process performance. With the proposed method, the DEA is firstly used to develop a pairwise comparison matrix, and then the AHP is applied to evaluate the performance of business process using the pairwise comparison matrix. The significant advantage of this hybrid model is the use of objective data instead of subjective human judgment for performance evaluation. In the case study, a project of business process reengineering (BPR) with a hydraulic machinery manufacturer is used to demonstrate the effectiveness of the DEA/AHP model.     

HYDROFORMING OF BIMETALLIC LINED PIPE

A new hydroforming process for manufacturing corrosion-resistant-alloy (CRA)-lined pipe is proposed to overcome the disadvantages in existing technologies, and a new kind of hydraulic expansion device for bimetallic CRA-lined pipe has been researched and developed. Its operational principal and technical characteristic is also introduced. The stress and strain in the liner and outer pipe during the hydroforming process have been analyzed and the mechanism of hydraulic expansion method is studied theoretically. The final forming pressure formula is suggested and the theoretical analysis is verified by experimental investigation. The results indicate that the new technology is feasible and can be applied in industrial production.     

Numerical simulation and analysis of power consumption and Metzner-Otto constant for impeller of 6PBT

Majority of non-Newtonian fluids are pseudoplastic with shear-thinning property, which means that the viscosity will be different in different parts of the stirred tank. In such mixing process, it is difficult to predict accurately the power consumption and mean shear rate for designing novel impeller. Metzner-Otto method is a widely accepted method to solve these questions in mixing non-Newtonian fluids. As a result, Metzner-Otto constant will become a key factor to achieve an optimum way of economical mixing. In this paper, taking glycerine and xanthan gum solutions as research system, the power consumption, stirred by the impeller composed of perturbed six-bent-bladed turbine （6PBT） with differently geometrical characteristics in a cylindrical vessel, is studied by means of computational fluid dynamics （CFD）. The flow is modeled as laminar and a multiple reference frame （MRF） approach is used to solve the discretized equations of motion. In order to determine the capability of CFD to forecast the flow process, the torque test experiment is used to measure the glycerine solution power consumption. The theological properties of the xanthan gum solutions are determined by a Brookfleld rheometer. It is observed that the power consumption predicted by numerical simulation agrees well with those measured using torque experiment method in stirring glycerine solution, which validate the numerical model. Metzner-Otto constant is almost not correlated with the flow behavior index of pseudoplastic fluids. This paper establishes the complete correlations of power constant and Metzner-Otto constant with impeller geometrical characteristics through linear regression analysis, which provides the valuable instructions and references for accurately predicting the power consumption and mean shear rate of pseudoplastic fluids in laminar flow, comparatively.     

RIGID-PLASTIC MECHANICAL MODEL FOR THE FORGING METHOD WITH HORIZONTAL V-SHAPED ANVIL

In order to decrease the anisotropy of mechanical properties, the rigid-plastic mechanical model for the forging method with horizontal V-shaped anvil is presented. The forging method, through the change of anvils shape, is able to control fibrous tissue direction, to improve the anisotropy of mechanical properties of axial forgings, to realize uniform forging. Therefore, the forging method can overcome the defect that conventional forging methods produce. The mechanism of the forging method with horizontal V-shaped anvil and the process of metal deformation are analyzed. The agreement of theoretical analysis with experimental study verifies the fact that the forging method with horizontal V-shaped anvil can control effectively the mechanical properties of axial forgings.     

Study of injection molding process simulation and mold design of automotive back door panel

Numerical simulation of the injection molding process of the outer panel of the automotive plastic rear door and mold design is presented here. Computer aided three-dimensional interactive application (CATIA) is employed to design the original automotive steel structure, and the modal and thermodynamic properties of the plastic back door outer panel are changed by changing the different injection materials of the back door outer panel. In order to efficiently design the panels, finite element analysis is used to verify whether the designed parts meet the mechanical properties requirements such as light weight, low fuel consumption, short production cycle, strong modeling design, high corrosion resistance and good recovery, the above main parameters have been evaluated, and the above main parameters are carried out evaluate. To simulate the injection molding process, computer aided engineering (CAE) software such as ANSYS and HyperWorks are used to analyze the back door of the selected material. After the numerical analysis, suitable material is selected, so that the modal and thermodynamic properties of the product could be satisfied as well as improved. Unigraphics NX (UG) is employed to design the convex and concave mold for the injection molding of the automobile’s plastic back door panel. Combined with the characteristics of the parts and the design requirements of the injection mold, the multi-scheme design of the pouring and cooling system is carried out. By comparing the effects of different gating and cooling systems on injection molding, the best gating and cooling system is selected. The artificial fish swarm algorithm is used to optimize the process parameters of the injection molding process, and the best combination of the injection molding process parameters of the outer panel of the rear door of the automobile is obtained.

     

塑料注射成形过程仿真软件的开发和应用

智能型3维注射成形过程仿真系统HSCAE　3D解决了用3维实体／表面模型取代中性层模型的关键性技术难题，通过数值计算与人工智能技术的结合，使仿真软件由传统的被动式计算工具提升为主动式优化系统。实验和实践证明，HSCAE　3D为注塑制品与模具的虚拟制造奠定了坚实的理论和技术基础，构成了注塑制品成形质量全面控制的核心技术，已在模具行业中得到了很好的应用。     

Comparison of crystallization characteristics and mechanical properties of polypropylene processed by ultrasound and conventional micro-injection molding

Ultrasound injection molding has emerged as an alternative production route for the manufacturing of micro-scale polymeric components, where it offers significant benefits over the conventional micro-injection molding process. In this work, the effects of ultrasound melting on the mechanical and morphological properties of micro-polypropylene parts were characterized. The ultrasound injection molding process was experimentally compared to the conventional micro-injection molding process using a novel mold, which allows mounting on both machines and visualization of the melt flow for both molding processes. Direct measurements of the flow front speed and temperature distributions were performed using both conventional and thermal high-speed imaging techniques. The manufacturing of micro-tensile specimens allowed the comparison of the mechanical properties of the parts obtained with the different processes. The results indicated that the ultrasound injection molding process could be an efficient alternative to the conventional process.     

POE增韧改性回收PP的注塑成型工艺及其性能

通过正交试验研究了回收聚丙烯(PP)的注塑成型工艺,并以经马来酸酐改性的乙烯-辛烯共聚物(POE)和改性POE+纳米CaCO3作为增韧剂对PP改性,研究了增韧剂加入量对回收PP的微观组织和力学性能的影响。结果表明:影响回收PP力学性能程度由大到小的工艺参数顺序为注塑温度、注塑压力、保压压力和保压时间,最佳工艺参数为注塑温度220℃,注塑压力70 MPa,保压压力55 MPa,保压时间40 s;两种增韧剂对回收PP均具有较好的增韧效果,最佳加入量均为25%;用改性POE+纳米CaCO3作为增韧剂的效果优于只使用改性POE作为增韧剂的改性效果。     

A study of optimization of injection molding process parameters for SGF and PTFE reinforced PC composites using neural network and response surface methodology

This study analyzed variations of mechanical characteristics that depend on the injection molding techniques during the blending of short glass fiber and polytetrafluoroethylene reinforced polycarbonate composites. A hybrid method including back-propagation neural network (BPNN), genetic algorithm (GA), and response surface methodology (RSM) are proposed to determine an optimal parameter setting of the injection molding process. The specimens are prepared under different injection molding processing conditions based on a Taguchi orthogonal array table. The results of 18 experimental runs were utilized to train the BPNN predicting ultimate strength, flexural strength, and impact resistance. Simultaneously, the RSM and GA approaches were individually applied to search for an optimal setting. In addition, the analysis of variance was implemented to identify significant factors for the injection molding process parameters and the result of BPNN integrating GA was also compared with RSM approach. The results show that the RSM and BPNN/GA methods are both effective tools for the optimization of injection molding process parameters.     

熔融挤压堆积成形质量分析

通过理论分析与工艺试验相结合，探索几种聚合物材料在不同工艺条件下的粘结质量问题，总结出不同材料在熔融挤压堆积成形工艺中的最佳喷嘴温度范围、成形室温度范围及合理层厚。这里结论对于选用成形材料和优化工艺参数提供了重要依据。     

精密注塑制品残余应力的试验研究及其计算

注塑残余应力对精密注塑制品的力学性能和光学性能等有重要影响,是精密注塑制品质量控制的关键指标之一。为研究注塑成形过程中残余应力的发展,以丙烯腈—丁二烯—苯乙烯共聚物(Acrylonitrile butadiene styrene,ABS)塑料为研究对象,对其模内蠕变行为进行试验研究。将热弹性模型计算的收缩应变与试验测量的收缩应变之间的差值定义为制件的模内蠕变,得到注塑工艺条件对模内蠕变的影响规律。在此基础上构建计算精密注塑制品残余应力的蠕变模型。模型中的材料弹性模量可由Tait方程计算得到,粘壶系数采用反演方法计算得到。利用该模型结合薄壳有限元法对ABS平板注塑件残余应力进行计算,对计算结果进行试验验证,并与普通的松弛模型计算进行比较。计算结果表明,该模型的计算精度高于普通的松弛模型,是解决精密注塑制品残余应力预测问题的新的有效方法。     

Microcellular injection molding process for producing lightweight thermoplastic polyurethane with customizable properties

A three-stage molding process involving microcellular injection molding with core retraction and an “out-of-mold” expansion was developed to manufacture thermoplastic polyurethane into lightweight foams of varying local densities, microstructures, and mechanical properties in the same microcellular injection molded part. Two stages of cavity expansion through sequential core retractions and a third expansion in a separate mold at an elevated temperature were carried out. The densities varied from 0.25 to 0.42 g/cm³ (77% to 62% weight reduction). The mechanical properties varied as well. Cyclic compressive strengths and hysteresis loss ratios, together with the microstructures, were characterized and reported.     

超薄塑件注塑成形特性的试验研究与数值模拟

薄壁注塑成形技术具有节约材料、降低成本、减少制品重量和外形尺寸等优点,可促进移动电话等电子产品的迅速发展,特别是超薄塑件的注塑成形技术在微机电领域具有巨大的应用潜力。但随着制品厚度的减小也使注射成形难度加大,填充过程更为复杂,成形特性有待探索。设计制造出可成形超薄塑件的模具,利用正交试验方法(田口方法)进行充模试验和数值模拟技术研究各工艺参数(注射速度、注射压力、熔体温度、注射量和制品厚度等)对超薄塑件注塑成形充模过程的影响。研究结果表明,制品厚度对超薄塑件的填充起决定性作用;注射量及注射速度对超薄塑件注塑成形的填充起主导作用,提高注射速度能大幅度地提高填充率;熔体温度和注射压力相对于注射量和注射速度只起次要作用,但在填充过程中,高的熔体温度和注射压力也是必要的。     

Optimum process conditions on shrinkage of an injected-molded part of DVD-ROM cover using Taguchi robust method

Plastic injection molding is an important process to produce thin-shell parts. However, the difficulty in adjusting optimum process conditions may cause defects of the injected-molded parts such as shrinkage. This study investigates on the optimum combinations of process conditions on shrinkage of an injected-molded part of the DVD-ROM cover based on Taguchi method. In doing this, a series of Moldflow analyses have been performed as per L₂₇ orthogonal array design with each analysis by means of the process conditions of mold temperature, melt temperature, injection pressure, injection time, and cooling time. In the meantime, signal-to-noise (S/N) ratio is utilized to determine the optimum combinations of the process conditions for shrinkage through analysis of variance (ANOVA). ANOVA is further used to find which of the process conditions are statistically significant. Finally, confirmation tests at the optimum combinations of the process conditions were executed to verify the robustness and the effectiveness of Taguchi method within 95% confidence interval. From the findings, it can be stated that Taguchi method is a powerful tool for evaluating the defect of shrinkage in the plastic injection molding.