S12微控制器C代码生成及基于CCP的标定技术

根据现代汽车电子系统V模式开发流程的需要,研究了针对S12微控制器的C代码生成和基于CCP的标定技术,包括如何利用RTW自动生成C代码并将其与手写底层I/O以及CCP驱动代码进行衔接和集成。实际应用结果表明,所提出的方法能够快速有效地进行嵌入式控制软件的开发、控制参数的在线标定及信号的实时测量。     

基于CCP协议的汽车ABS标定系统CAN通信模块的研发

CAN总线以其通信效率高、可靠性强、连接方便等优点在汽车电子领域得到了广泛的应用。CCP协议作为CAN通信系统的标定协议,以主从机通信模式实现了CAN网络中标定工具对一个或多个控制器的在线标定和实时监测。基于CCP协议的汽车ABS标定系统CAN模块的研发,为ABS控制系统的开发提供了准确、实时的通信保证,显著缩短了ABS控制系统的开发周期。     

A study on the various features for effective control chart pattern recognition

The identification of various unnatural patterns that are usually exhibited in quality control charts leads to more focussed diagnosis and, thereby, significantly minimises the effort towards effective troubleshooting. Feature-based control chart pattern (CCP) recognition systems have the advantage that the users can easily understand how a particular pattern is identified. Pham and Wani have presented a feature-based heuristic approach for CCP recognition which can differentiate six types of CCPs, based on the extraction of nine shape features. The extraction of some of these features requires users’ inputs and, thus, this CCP recognition system is not truly automated. Moreover, many real-life situations require detection of all of the eight basic CCPs, including stratification and systematic patterns. The extraction of the features after the scaling of pattern data into an (0, 1) interval can ensure that the magnitudes of the features are independent of the mean and standard deviation of the underlying process. But the distinction between normal and stratification patterns is lost when the pattern data are scaled. A CCP recogniser that will identify a stratification pattern, therefore, needs to be developed using unscaled pattern data. In this paper, potentially useful 32 features, the extraction of which do not require users’ inputs of any form, are proposed. The magnitudes of these features are independent of the process mean and are considerably insensitive to changes in the process standard deviation. An easy mechanism for the determination of the optimal set of features and a heuristic is also presented. Sensitivity studies on the performance of the heuristic show that it is robust against the estimation error of the process mean and is reasonably robust against the estimation error of the process standard deviation. Thus, it has enough potential for use in real-time process control applications.     

全景环形透镜三维空间成像展开算法的研究

全景环形透镜(PAL)利用平面圆柱投影法(FCP),将三维空间的像成在一个环形区域,由于其成像原理不同于人眼习惯的中心投影法(CCP),故不利于人眼的观察以及测量,极大地限制了PAL的应用领域。现提出了一种新的展开方法,实现了从FCP到CCP的转换,结果表明,三维立体空间环形像的展开效果良好,更符合人的观察习惯,极大地拓展了PAL的应用领域。     

Modelling of the Polished Profile in Computer-Controlled Polishing by a Sub-Aperture Pad

High-quality part surfaces with high surface finish and form accuracy are increasingly in demand in the mold/die and optics industries. The computer-controlled polishing (CCP) is commonly used as the final procedure to improve the surface quality. This paper presents a theoretical and experimental study on the polished profile of CCP with sub-aperture pad. A material removal model is proposed based on the evaluation of the amount of material removed from the surface along a direction orthogonal to the tool path. The model assumes that the material removal rate follows the Peterson equation. The distribution of the sliding velocity at the contact region is presented. On the basis above, the approaches to calculate the polished profiles are developed for the sub-aperture pad polishing along a straight path and a curved path. The model is validated by a series of designed polishing experiments, which reveals that polishing normal force, angular spindle velocity, feed rate and polishing path all have effects on the polished profile. The result of experiments demonstrates the capability of the model-based simulation in predicting the polished profile.     

Control chart pattern recognition using feature-based learning vector quantization

The reported learning vector quantization (LVQ) network-based control chart pattern (CCP) recognizers in literature use raw process data as the input vector and can recognize six basic CCPs only. In this paper, an LVQ network-based CCP recognizer is presented that can recognize eight basic CCPs, using seven extracted shape features from the pattern data as the input vector. The recognition performance of this recognizer is compared with the LVQ network-based recognizer that uses raw process data as the input vector. The results show that the feature-based recognizer results in substantially better recognition performance than the raw data-based recognizer. The confusion matrix reveals that the recognition performance of the feature-based recognizer can be improved further if any feature that is more powerful in discriminating shift and trend pattern can be identified. Comparison of performances of LVQ network-based and multilayer perceptrons (MLP) network-based recognizers (both using extracted features as input vector) reveals that the LVQ network-based recognizer requires much lesser learning time than the MLP network-based recognizer, but results in little inferior recognition performance.     

Optimal fitting of strain-controlled flattenable mesh surfaces

In this paper, an eye-in-hand vision-based robotic bin-picking system is proposed. The system can identify the pose of a plumbing part from a pile and grip it correctly. A monocular eye-in-hand camera and a laser projector are employed to reconstruct the 3-D point cloud of plumbing parts stacked together. The projection direction of the laser line projector is controlled to change in order to scan the pile of objects while the camera is observing. 3-D points can then be determined by the a priori known geometry between the camera and the laser line projector. To estimate the pose of an object, the iterative closest point (ICP) is employed to match the point clouds of the object and the model. The transformation between the object and the model can thus be determined. A computed closer point (CCP) approach is proposed to estimate the pose of an object since the deviation from the object to the model is initially large in nature. The proposed CCP approach combining with the ICP algorithm can improve the success rate and accuracy of point cloud matching. The proposed system has been validated by experiments with potential applications in production lines.     

A hybrid rough-cut process planning for quality

This paper proposes a hybrid approach to develop a rough-cut process planning for quality. The approach aims to determine key process alternatives with an adequate process capability by systematic quality planning and assessment methods during the initial planning stage of the product development cycle. It consists of four steps: (1) identification of quality characteristics (2) planning of the process quality by combining quality function deployment (QFD) with the process failure mode and effect analysis (FMEA) (3) a selection of process alternatives, and (4) an assessment of process quality through a quality measure index, called the composite process capability (CCP). The process alternatives with an adequate CCP selected during the early design stage can then be not only used as the guidelines for detailed process planning but also as feedback for the product design and other functions for design evaluation and improvement. This approach is helpful to reduce or even eliminate the iterations of modification of process plans. A prototype system called the rough-cut process planning for quality (RPPFQ) has been developed for validation. A case study concerned with a satellite frame part is presented to illustrate the approach and prototype system in this paper.     

Experiments and numerical approaches to ductile tearing in an 2024-T351 aluminium alloy

Ductile fracture of an 2024-T351 aluminium alloy has been investigated using a central crack panel (CCP). In order to predict rupture, two models using the local approach to fracture mechanics were verified: the uncoupled Rice and Tracey void growth model and the coupled Rousselier model based on continuum damage mechanics. A finite element analysis has been performed in order to verify the capability of these models to predict the crack extension.     

基于PXI总线的电驱变速箱齿轴耐久测试系统的开发

使用NI公司的LabVIEW2010、PXI平台成功搭建一套电驱变速箱齿轴耐久测试系统。其中采用CCP通讯协议完成与混合动力控制器的控制和监测,同时通过定制的远程通讯协议完成与台架测控软件的通讯。采用高速数据采集卡进行数据采集和实时报警。