DVE architecture based on message category

By importing the idea of P2P,and transmitting messages among clients directly into the client-server architecture,a new hybrid architecture was presented with the help of AOI technology and message category.Theoretical analysis of this architecture was presented in detail.A series of simulation experiments was carried out to verify its effectiveness.Results indicate that the new architecture produces less server message workload than traditional architectures,which can improve the scalability of DVE systems.     

惯性导航系统航向姿态计算算法研究

通过初始对准,惯性航向姿态系统获得了初始坐标,紧接着就是在运动体的运动中不断地计算运动体的航向和姿态.就惯性航向姿态系统的航向和姿态计算算法进行探讨和研究,以寻求最佳计算算法.     

Total quality control for automotive raw foundry brake disks

In this paper, a solution for the automatic raw foundry brake disk dimensional characterisation and visual inspection for the automotive industry is presented. Three different computer vision techniques are used: a calibrated 3D structured-light vision technique, for dimensional characterisation and inspection; a 3D uncalibrated structured-light vision technique for local fault detection; and a common 2D-vision technique for a further local fault recognition. A new and fully automated 3D-calibration procedure for piece dimensional characterisation is also described. The whole system is an accurately synchronised blending of mechanics, automation, computer vision and robotics. Results from industrial implementation are presented.     

Managing the process of passenger security control at an airport using the fuzzy inference system

Elements of air transport infrastructure as well as passengers and aircraft are constantly at risk of terrorist attack. One of the most important preventative methods is the security control of persons and baggage at airports. Managing this process requires finding a compromise between high capacity of the terminal and the high effectiveness of the security control. The purpose of this study is to show the applicability of an expert system, which assists security managers in deciding how to organise the security screening process. Due to the important role of the human factor, the need to use expert's opinions and the high uncertainty and imprecise nature of information, the developed model and computer tool FUPSCA (FUzzy Passenger Security Control Assessment) uses the fuzzy sets theory and a fuzzy inference system. It's use allows us to adjust the operating parameters of the security screening checkpoint, namely the WTMD sensitivity, number of employees and the frequency of manual controls, to the current level of terrorist threat. As a result of the study it was found that if we want to achieve higher security control effectiveness we should first increase the WTMD's sensitivity and only then increase the frequency of additional manual controls and not the other way round. Of course the FUPSCA system provides specific, quantitative answers. In the future it will be necessary to manage the operation of the passenger security control system using multi-criteria evaluations of: capacity, effectiveness, passenger comfort. FUPSCA will be able to effectively support this process.     

Automatic expert system based on images for accuracy crop row detection in maize fields

This paper proposes an automatic expert system for accuracy crop row detection in maize fields based on images acquired from a vision system. Different applications in maize, particularly those based on site specific treatments, require the identification of the crop rows. The vision system is designed with a defined geometry and installed onboard a mobile agricultural vehicle, i.e. submitted to vibrations, gyros or uncontrolled movements. Crop rows can be estimated by applying geometrical parameters under image perspective projection. Because of the above undesired effects, most often, the estimation results inaccurate as compared to the real crop rows. The proposed expert system exploits the human knowledge which is mapped into two modules based on image processing techniques. The first one is intended for separating green plants (crops and weeds) from the rest (soil, stones and others). The second one is based on the system geometry where the expected crop lines are mapped onto the image and then a correction is applied through the well-tested and robust Theil–Sen estimator in order to adjust them to the real ones. Its performance is favorably compared against the classical Pearson product–moment correlation coefficient.     

Parsimonious cooperative distributed MPC algorithms for offset-free tracking

We propose in this paper novel cooperative distributed MPC algorithms for tracking of piecewise constant setpoints in linear discrete-time systems. The available literature for cooperative tracking requires that each local controller uses the centralized state dynamics while optimizing over its local input sequence. Furthermore, each local controller must consider a centralized target model. The proposed algorithms instead use a suitably augmented local system, which in general has lower dimension compared to the centralized system. The same parsimonious parameterization is exploited to define a target model in which only a subset of the overall steady-state input is the decision variable. Consequently the optimization problems to be solved by each local controller are made simpler. We also present a distributed offset-free MPC algorithm for tracking in the presence of modeling errors and disturbances, and we illustrate the main features and advantages of the proposed methods by means of a multiple evaporator process case study.     

Structural synthesis of 5 DoFs 3T2R parallel manipulators with prismatic actuators on the base

A method is presented to synthesize 5 degrees of freedom (DoFs) of 3 translational and 2 rotational (3T2R) parallel kinematic structures. This method is based on the theory of linear transformation and geometrical analysis. Central to this method is a set of novel 5 DoFs 3T2R parallel mechanisms (PMs). Based on the legs configuration, the generated mechanisms are classified. Moreover, the promising mechanisms of each class are introduced with respect to some criteria, i.e.: (a) degree of coupling between the actuators and degrees of freedom; (b) easy kinematics and control command; (c) easy construction (or low cost construction); and, (d) manufacturability. With reference to these criteria, some discussions are given on the promising mechanisms. Finally, to demonstrate the role of legs configuration in relation to the characteristics of a manipulator, the kinematic analysis of two of the introduced mechanisms is compared.     

基于局部峰值方差检测的改进DUET算法研究

DUET(degenerate unmixing estimation technique)算法是一种典型的盲源分离方法,而混合参数估计是DUET算法的重要组成部分,其估计精度直接影响到源信号的分离效果。针对混合参数估计,提出了一种基于局部峰值方差检测的改进DUET算法。首先利用DUET算法模型中混合参数创建直方图,根据直方图上信号占优的特点,把直方图划分成若干个子区域,计算每个子区域的方差,然后利用排序算法检测出最大的P个方差(P为源信号的个数),这P个方差所在子区域峰值的横纵坐标即是混合参数。此算法改进了原有DUET算法中混合参数估计的智能性和精度,通过语音分离的仿真实验和实录实验表明,此算法简单有效,并且估计源信号的精度有了提高。     

温度测试系统的动态建模与特性分析

本文对瞬时测温系统的动态特性进行研究。为研究热电偶动态性能建立了动态标定实验,并通过一种特殊白化滤波器的广义最小二乘法对该系统进行系统辨识,建立动态数学模型。根据动态数学模型计算出测试系统的时域、频域的动态性能指标。     

项目教学法在《研华工控》新课程教学中的探索与实践

围绕《研华工控》新课程的教学,提出了项目教学的总体方案,对具体项目进行了设置,并在教学全过程中予以了实施。学生学习积极性很高,实践操作技能及工业控制应用系统设计能力得到明显提高,实践证明效果良好。