基于频谱法的车辆音频测速研究

本文对目前现有车辆测速方式的现状分析,设计出一种利用音频测速的装置,并通过计算机实验分析表明,该装置的确能够用于实际生活中的车辆测速,具有经济,简便的特点.     

基于反射式黑白码盘的模型车测速装置

针对在模型车上使用的测速装置仅戍本较高的旋转编码器的现况,根据实际智能模型车的测速需要,提出了一种能够实现精确测量成本又低的测速装置.该装置利用光遇到黑白条文反射强弱不同的原理,使用光电管与自制黑白码盘实现测速,通过比较芯片最终输出标准方波波形,直接输入单片机使用.该测速装置能够实现精确测量车速,同时很大程度上降低成本,具有制作容易,操作简单易于实现等优点.     

机动车视频测速中关键技术的研究与实现

针对通过视频检测机动车行驶速度方法精度低、易受阴影十扰和无法对多辆机动车同时测速的问题,该文介绍了一种基于机动车视频测速模型检测机动车行驶速度的新方法。基于该测速模型实现的机动车视频测速系统取得了令人满意的测速效果,在一定条件下其视频测速精度可达到98．33％。     

MCS－8098单片机在变压交流调速中的应用

本文用编码器作为测速装置，构成反馈环，利用ＭＣＳ－８０９８单片机通过变压调速达到在负载可变的情况下，转速恒定，是一种简单、实用的变压调速系统。     

MCS—8098单片机在变压交流调速中的应用

本文用编码器作为测速装置，构成反馈环，利用ＭＣＳ－８０９８单片机通过变压调速达到在负载可变的情况下，转速恒定，是一种简单、实用的变压调速系统。     

一种实用的两相流速度测量方法

本文提出了一种实用的两相流速度测量方法——波形法．从理论上分析了波形法的测速原理，且通过对现场采样的速度信号进行分析比较，证明了波形法可以取代相关法测速。从响应时间、适用的范围、与平均速度的接近程度及可靠性几方面比较了二种方法的优缺点，并提出了一种能计算出更接近平均速度的两相流速度测量方法的设想。     

基于多传感器信息融合的水下运动体速度测量

针对水下运动体测速中存在的难度大、精度低等问题,提出一种基于加速度计和机械测速装置的融合测速方法。该方法实质上是一种改良的模糊自适应卡尔曼滤波,在常规卡尔曼滤波的基础上,引入了自适应参数,并通过模糊控制器对残差的监控来实时调整自适应参数。经Matlab仿真和实际试验证实:该方法可以有效地提高卡尔曼滤波器的跟踪性,并改善滤波效果,适用于通用的水下运动体测速。     

ARM皮带秤控制器的高精度测速技术研究

针对皮带秤使用脉冲计数方法进行速度测定精度不高,影响了皮带秤的计量精度,在原有的皮带秤装置的基础上,采用新型的ARM控制器,提出了一种基于此控制器的测速方法,进行了高精度测速技术的研究.实践表明,以ARM为控制器的皮带秤测速精度高,响应快,误差小.     

一种提高全数字化直流调速系统稳态控制精度的方法

根据系统稳态控制精度的要求，对数字触发器分辨率、数字测速装置、CPU运算等字长和光电码盘P值的计算选择做了定量分析，并对M／T法测速存在的缺点提出了改进方法。为单片机控制高精度、快速直、交流可逆调速系统提供了参考。     

基于正交编码器高精度测速方法的研究

根据正交光电编码器测速原理,在分析了M法测速的测量误差和分辨率的基础上,提出了一种改进的转速高精度测量方法——变M法,即同时测量正交的两组脉冲序列的上升沿和下降沿,极大的减小了转速和转角测量误差,提高了分辨率。还提供了一种适用于工业现场环境条件的,基于正交编码器测速算法的虚拟仪器软硬件设计方案及其实验效果。     

Conversion method and system

In the classical conversion method, the light that passes the medium is converted to the photosignal. Then, it is amplified by an amplifier having linear characteristics. Considering the amplitude of the amplified signal, the measured parameter is determined. In the proposed conversion method, the intensity of the reference light that falls on the medium is inversely modulated with respect to the absorption function. The intensity of the light used for the measurement is kept constant. The intensity modulated reference light and the measurement light, which are in inverse phases, pass through the medium subsequently. Then, they are detected by a photodetector. At the output of the photodetector, the phase changing instant of the obtained signal and the duration between the starting instant of the reference light and the phase changing instant are determined. Considering this duration, the value of the measured parameter is determined. The proposed conversion method linearizes the conversion phenomenon. The photodetector does only detect the instant at which the reference light and the measurement light are similar. The photodetector operates as an indicator. The measured parameter is converted to the pulse duration or the number of pulses. The value of the measured parameter can be directly obtained at the output of the photodetector. The comparison and the mathematical operations are directly achieved on lights. Analysis of the proposed method and application examples are given in the paper.     

Numerical and experimental study of the virtual quadrupedal walking robot-semiquad

SemiQuad is a prototyped walking robot with a platform and two double-link legs. Thus, it is a five-link mechanism. The front leg models identical motions of two quadruped's front legs, the back leg models identical motions of two quadruped's back legs. The legs have passive (uncontrolled) feet that extend in the frontal plane. Due to this the robot is stable in the frontal plane. This robot can be viewed as a "virtual" quadruped. Four DC motors drive the mechanism. Its control system comprises a computer, hardware servo-systems and power amplifiers. The locomotion of the prototype is planar curvet gait. In the double support our prototype is statically stable and over actuated. In the single support it is unstable and under actuated system. There is no flight phase. We describe here the scheme of the mechanism, the characteristics of the drives and the control strategy. The dynamic model of the planar walking is recalled for the double, single support phases and for the impact instant. An intuitive control strategy is detailed. The designed control strategy overcomes the difficulties appeared due to unstable and under actuated motion in the single support.Due to the control algorithm the walking regime consists of the alternating different phases. The sequence of these phases is the following. A double support phase begins. A fast bend and unbend of the front leg allows a lift-off of the front leg. During the single support on the back leg the distance between the two leg tips increases. Then an impact occurs and a new double support phase begins. A fast bend and unbend of the back leg allows the lift-off of the back leg. During the single support on the front leg the distance between the two leg tips decreases to form a cyclic walking gait.The experiments give results that are close to those of the simulation.Funding for SemiQuad was primarily provided by the CNRS and the region Pays de La Loire.     

Designing the rule classification with oversampling approach with high accuracy for imbalanced data in semiconductor production lines

The product quality is the major factor for enhancing the production ability and competitiveness. Decreasing the cost and increasing production capacity are common approaches to realize the enhancement of the product quality. The production managers apply various multimedia data to evaluate the product quality. For example, capturing the stamping sound to evaluate the correct cutting and taking the component image to measure the chip positions are common heterogeneous multimedia data that are applied to manufacturing. However, the production managers prefer to minimize the number of defective products, e. g. the secondary operation and fixing the product tolerance in the assembly stage, to fitting the production target. Therefore, contrasting the defective product identification procedure with high accuracy becomes a challenge due to the decrease of the number of the defective products. In this paper, we propose the Rule Classification with Oversampling (RCOS) approach to provide the high accuracy with few defective products. The proposed RCOS includes the oversampling technique and the rule classification approach to emphasize the properties of the defective products and provide the precise classes. Given few defective products, capturing the properties of the failure is difficult. The RCOS considers the revised Synthetic Minority Over-Sampling Technique (SMOTE) to highlight the failure properties, and then the rule model is considered to extract the root cause of the defective products. We implement the proposed RCOS in the semiconductor production line. From the experiment results, the proposed RCOS provide about at most 98% in accuracy, and the comparison shows that the results have been improved in common criteria e. g. the true-positive rate, G mean, F1 score, and False Alarm Rate. Therefore, the proposed RCOS provides high practicality for the implementation consideration.

     

一种基于二维可逆映射的图像加密算法

提出了二维可逆映射在图像加密中的应用.可以通过置乱图像像素位置实现图像加密.二维可逆映射可以高效地实现图像像素置乱.二维可逆映射由压缩拉伸和折叠两个子映射组成.压缩拉伸映射,使原始图像变换成线,折叠映射使线变换成图.所有可逆映射构成了可逆映射集合.经过扩散处理改变像素值,实现图像加密.二维可逆映射的引入扩大了密钥空间,并增强了对密钥变化的敏感度.新的加密方法提高了加密图像的安全性且加快了加密速度.仿真验证了二维可逆映射图像加密算法的有效性.     

FB-CS模型的两层嵌套机动目标跟踪算法

针对转弯机动目标,提出了一种两层模型嵌套的跟踪算法.算法的内层模型由基于函数的“当前”统计(Function based current statistic,FB-CS)模型构成,该模型在“当前”统计(Current statistic,CS)模型的基础上,通过加权一个以新息方差之迹为参数的活化函数,对加速度方差和机动频率进行自适应处理,再针对目标的速度方向角进行滤波,将获得的角速度估计值作为外层的输入;外层模型由曲线模型构成,其方向角度、角速度和角加速度由内层模型提供.由于既准确估计目标的角速度,又设计了合理的运动模型,算法显著提高了转弯机动目标的跟踪精度.仿真实验验证了算法的有效性.     

Passive mixing of co-flowing slugs in grooved microchannels

The anisotropic grooves in a microchannel induce spiral circulation around the flow axis. The stretch and fold of the streams result in a passive mixing. This article describes the effectiveness of induced crossflow, arising from the grooves, placed at the floor of the microchannel. The results from numerical simulation show the extent of local mixing achieved at various positions around the groove. The emphasis here is to understand the mixing when the two streams enter the channel, and displace air while flowing alongside each other. Microchannels with slanted grooves and staggered herringbone type grooves are considered here. The FLUENT 6.2 software and the Open FOAM software were used for the simulation. The latter was primarily utilized for tracking of the interface when a liquid slug displaced air from the micromixer. At a Reynold’s number of about 1.0, low velocity pockets could be identified near the two ends of the ridges. These pockets did not support crossflow and mixing. The herringbone type micromixer was found to have the best mixing effectiveness, when the advection dominates mixing. This advantage is mostly lost at the higher values of diffusivity, as a crossflow became less important for mixing. These observations were made when one of the streams is 1.5 times more viscous than the other, and the mixture-rule governed the viscosity of the mixed stream. When the liquid front enters the microchannel for the first time, the front had to displace air from the channel. At first, the upper part of the channel was swept. This was immediately followed by the sweeping of the groove-part in the floor. Higher hydraulic resistance in the grooves resulted in this non-uniform movement of the front. The co-flow of streams could either be continuous over the entire length of the channel, or in the form of slugs that maintained an interface with air. At a particular position in the channel, the extents of mixing were compared for the two modes of co-flow. The extent of mixing was found smaller in the slug, next to the interface with air. Lack of axial dispersion with preceding liquid stream seems to be the reason for this trend.     

粗糙集理论在故障诊断中的问题分析

粗糙集理论能对系统中的冗余信息进行约简,但其处理过程完全基于样本集,样本集的完备性对其处理结果有直接影响.对粗糙集理论及其在故障诊断中属性约简存在的问题进行了分析,通过实例证明了在故障样本集不完备的情况下,利用粗糙集进行的属性约简会由于新故障样本的引入而导致前后约简结果的不一致,从而影响诊断的准确性;指出了该问题产生的关键原因及解决的办法,并给出了相关的实现算法,以提高系统的故障诊断自适应性.     

Sensor system of a small biped entertainment robot

SDR-4X II is the latest prototype model of a small biped entertainment robot. It is the improved model of SDR-4X. In this paper we report on the sensing system of this robot, which is important and essential for a small biped entertainment robot which will be used in the home environment. One technology is the design of the motion sensing system, i.e. the inclination sensor system and the force sensor system which obtains the inclination of the trunk and the foot with force. Another technology is the real-world sensing system. One aspect is the touch sensing system. The robot is used in a normal home environment, so we should strongly consider the safety aspects for human. Another is the vision sensor system. The configuration and the distance image acquisition are explained. Next is the audio sensor system which obtains the sound and the voice information. The hardware system and the direction recognition are explained. These sensing systems are the key to making the biped robot walking and dynamic motion highly stable, and understanding the real-world around the robot.     

机器人足球比赛截球策略设计

在机器人世界杯足球锦标赛(TheRobotWorldCup,简称RoboCup)中,截球效率直接影响到比赛的结果。通过足球截球模型,建立方程,从而求出截球位置。解方程的根是提高截球效率的关键,本文采用高效的弦割法来快速计算方程的根。试验发现方程曲线的变化对弦割法解方程根的效率有很大影响,曲线的形状直接影响了弦割法的收敛速度。为加速收敛性,对弦割法进行了优化。最后与优化前的弦割法以及二分法进行了比较,结果表明优化后整体性更为高效,很好地满足了比赛的要求。     

Greedy algorithms for eigenvalue optimization problems in shape design of two-density inhomogeneous materials

This paper studies the eigenvalue optimization problems in the shape design of the two-density inhomogeneous materials. Two types of greedy algorithms are proposed to solve three optimization problems in finite element discretization. In the first type, the whole domain is initialized by one density. For each problem of the eigenvalue optimizations, we define a measurement of the element, which is the criterion to determine the ‘best’ element. We change the density of the ‘best’ element to the other density. Then the algorithm repeats the procedure until the area constraint is satisfied. In the second type, the algorithm begins with the density distribution satisfying the area constraint. Also, according to the measurement of the element, the algorithm finds a pair of the ‘best’ elements and exchanges their densities between each other. Furthermore, the accelerating greedy algorithms are proposed to speed up both two types. Three numerical examples are provided to illustrate the results.