Experimental Study of the Influence of Intrinsic Parameters on the Thermal Reactivity of Sawdust, Polyethylene Terephthalate and Composite

Several works have been based on the study of thermal variations in biomass to derive more valuable products such as fuels capable of replacing oil in the event of a crisis or activated carbon used as an adsorbent material, widely used in industry for the elimination of unwanted materials, both in liquid and gaseous environments. A study of thermal parameters such as: heating speed, retention time, drying temperature, carbonization temperature, particle size, was carried out with the aim of determining the characteristic factors of the carbonization of Polyethylene terephthalate (PET), sawdust (SC) and sawdust/polyethylene terephthalate (CPS) mixture. The results of the immediate analysis revealed a very low level of ash in PET (0.013%) compared to the level of ash in sawdust (2.9%), as well as a high level of fixed carbon (82.960%), which suggests the presence of mineral oxides and a significant carbon matrix unlike PET, which indicates a very significant organic matrix (essentially made up of organic matter) with the absence of mineral oxides. The study of thermal parameters showed the water loss from Sawdust (SC) and the Sawdust/Polyethylene terephthalate (CPS) mixture, an increase with temperature, unlike that of PET whose variation is essentially zero. Without heat treatment, sawdust alone contains approximately 7% water. The optimal drying temperature for this study is 110˚C for a stay of 24 hours. It appears that the largest mass losses for the PET samples are between 87.19% and 96.05%, followed by that of the mixture, between 47.33% and 64.37%. And the lowest are observed, those of sawdust (from 24.02% to 62.6%). However, here we can say that the influence of the mass is not great, given the slight difference between the losses by temperature. The results of the study of the influence of grain size showed that the differences are insignificant, even if we vary the diameter of the grains from simple to triple. To better minimize physical constraints such as the intragranular diffusibility of the volatile matter and the homogeneity of the temperature in the grains, 75 μm particles are found to be optimal for our study. It can be noted when studying the heating rate that the mass loss at the end of the reaction is approximately the same depending on each precursor material. However, it has been demonstrated that the heating rate strongly influences the nature of the reaction products both for volatile materials and for the solid residue as well as on the kinetic parameters of the chemical reaction. Furthermore, the variation in apparent density shows a decrease as a function of the increase in the residence time of the materials in the reactor. As the carbonization time increases, the apparent density decreases. We note, for the lignocellulosic material, that the apparent density stabilizes after 60 minutes.

Robust visual tracking for manipulators withunknown intrinsic and extrinsic parameters

This paper addresses the robust visual tracking of multi-feature points for a 3D manipulator with unknown intrinsic and extrinsic parameters of the vision system. This class of control systems are highly nonlinear control systems characterized as time-varying and strong coupling in states and unknown parameters. It is first pointed out that not only is the Jacobian image matrix nonsingular, but also its minimum singular value has a positive limit. This provides the foundation of kinematics and dynamics control of manipulators with visual feedback. Second, the Euler angle expressed rotation transformation is employed to estimate a subspace of the parameter space of the vision system. Based on the two results above, and arbitrarily chosen parameters in this subspace, the tracking controllers are proposed so that the image errors can be made as small as desired so long as the control gain is allowed to be large. The controller does not use visual velocity to achieve high and robust performance with low sampling rate of the vision system. The obtained results are proved by Lyapunov direct method. Experiments are included to demonstrate the effectiveness of the proposed controller.

Dependence of Amorphous Formation Ability on Intrinsic Parameters in Dy-Gd-Co-Al Alloys

A series of Dy（Gd）-based bulk amorphous alloy rods were prepared by water-cooled copper mold method. Thermal stability and structure of Dy-Gd-Co-Al alloys were investigated by differential scanning calorimetry and X-ray diffraction, respectively. The results show that the Dy-Gd-Co-Al alloys have good glass-formation ability, and the Dy31Gd25Co20Al24 alloy can be readily cast into full glassy rods up to 5 mm in diameter. The glass-forming ability of multicomponent alloys was greatly dependent on their chemical interaction and the equivalent bond parameters among atoms such as equivalent electronegativity difference, equivalent atomic size parameter. The Dy （Gd）-based bulk amorphous alloys could be expected as potential functional materials.

The Intrinsic Electron with Its Properties Such as Inner Structure and Self-Mass Is in Conflict with Quantum Field Theory

The quantum field theory (QFT) is one of branches of the Standard Model. According to QFT, quantum fields are the primary entities and particles are the excitations of these fields, coming in discrete lumps with no inner structures and with properties assigned by declaration. Such view is in conflict with the observed vacuum energy density, 140 orders of magnitudes less than required by the QFT. In addition, such view is challenged by Aphysical Quantum Mechanics (AQM), a deeper quantum theory. According to AQM, the fundamental understanding of quantum reality is expanded by the addition of two fundamental categories, aphysical and elementary consciousness of elementary particles. Based on AQM and as an example, the total ontology of the intrinsic (fundamental) electron is presented with its inner structure of perfect geometry consisting of the physical charged c-ring and aphysical cylinder, and with its properties such as self-mass, spin, magneto-electrostatic field configuration and magnetic moment. The position parameter in the inner structure demonstrates that there are no two identical intrinsic electrons in the Universe thus placing a question mark over the QFT principle of indistinguishability.

Detection of kinematics parameters of index finger movement with high-speed video camera

Synergic movement of finger's joints provides human hand tremendous dexterities,and the detection of kinematics parameters is critical to describe and evaluate the kinesiology functions of the fingers.The present work is the attempt to investigate how the angular velocity and angular acceleration of the joints of index finger vary with respect to time during conducting a motor task.A high-speed video camera has been employed to visually record the movement of index finger,and miniaturized(5-mm diameter) reflective markers have affixed to the subject's index finger on the side close to thumb and dorsum of thumb at different joint landmarks.Captured images have been reviewed frame by frame to get the coordinate values of each joint,and the angular displacements,angular velocities and angular acceleration can be obtained with triangle function.The experiment results show that the methods here can detect the kinematics parameters of index finger joints during moving,and can be a valid route to study the motor function of index finger.

Effect of Source to Camera Distance and Count Rate on Intrinsic Uniformity of SPECT Gamma Camera

In this research, the excellent parameter for regular Quality Control (QC) testing of intrinsic uniformity for dual-head Single Photon Emission Computed Tomography (SPECT) gamma camera is determined. The integral and differential intrinsic uniformity tests for both Useful Field Of View (UFOV) and Centre Field Of View (CFOV) were done by insertion a point-source of 99mTc in front of the detectors with detached collimators to measure the effect of source to camera distance and a count rate on intrinsic uniformity. The result reveals that the best intrinsic uniformity image is obtained at source-to-camera distance of 3 m and a count rate between 16 and 60 M.

3D Motion Parameters Determination Based on Binocular Sequence Images

Exactly capturing three dimensional (3D) motion i nf ormation of an object is an essential and important task in computer vision, and is also one of the most difficult problems. In this paper, a binocular vision s ystem and a method for determining 3D motion parameters of an object from binocu lar sequence images are introduced. The main steps include camera calibration, t he matching of motion and stereo images, 3D feature point correspondences and re solving the motion parameters. Finally, the experimental results of acquiring th e motion parameters of the objects with uniform velocity and acceleration in the straight line based on the real binocular sequence images by the mentioned meth od are presented.

The Influence of Tetranychus urticae Koch (Acari: Tetranychidae) Life Table and Reproductive Parameters by Applying Si on Bean at Library Condition

Two-spotted spider mite, Tetranychus urticae Koch, is one of the important pests of bean, which can cause severe damages on it. Silicon is one of the micronutrient elements, as its spray on the leaves can decrease the population of the pest. In this research, the impact of four different doses of Si (0, 1, 1/5, 2 ppm) was investigated on biological and population growth parameters of T. urticae. The experiments were carried out in Petri dishes in an incubator at 25°C ± 2°C, 65% ± 5% RH and 16 L: 8 D. The duration of developmental stage was significantly affected by Si dose. The longest immature period, the shortest longevity of females and the shortest oviposition period were obtained at 2 ppm. In addition, Si dose significantly affected population growth parameters of the mite. The intrinsic rate of natural increase (rm) of the mite ranged from 0.246 to 0.215 day which lowest and the highest values were at 2 ppm and control plants, respectively. The lowest net reproductive rate (R0) and finite rate of increase (λ) of the mite and the highest value of mean generation time (T) and doubling time (DT) were estimated at 2 ppm. The results of this peruse represented that 2 ppm had better potential for decreasing the population of the two-spotted spider mite, and it can be used in the mite integrated pest management programs.

Three-dimensional motion parameters estimation from stereo image sequences based on infrared reflective markers

In this paper,an innovative 3D motion parameters estimation method from stereo image sequences based on infrared(IR) reflective markers is presented.It was assumed that two high speed CCD cameras had been calibrated previously.The method consists of the following steps:1) the coordinate of several markers and depth map for each stereo pair was determined from the sequences of stereo images by relations of markers' coordinate the correspondence between markers was established,2) the 3D motion parameters of the target was computed based upon the matched markers' coordinate,and 3) translated 3D motion parameters estimation into the problem of least square according to the movement model of the object to be measured.Without using line,curve or corner correspondence,this method can calculate the depth of these markers feature easily and quickly in contrast to traditional approaches.The two CCD cameras work on 200 f/s,and each processing cost time is about 3 ms.It was found that,by using several markers and a large number of stereo images,this method can improve the computational speed,robustness and numerical accuracy of the motion parameters in comparison with traditional methods.The virtual simulation experiment was conducted using synthesized stereo image sequences based on 6-DOF motion platform and the experimental results proved the validity of our approach and showed that the translation and rotation precision is up to 0.1 mm and 0.1°.

针对十参数标定模型的导航避障相机影像精确校正

十参数标定模型是近景摄影测量中一种经典的内参标定模型。在影像畸变校正中,如果利用此模型采用直接重采样方式会产生空洞条纹,而常规的间接重采样方式虽无空洞产生,但在畸变较大的非中心区域同样无法得到较好的校正效果。针对此问题,本文提出了一种针对十参数标定模型的影像牛顿迭代精确校正算法。首先利用十参数标定模型将像点理想值和实际值进行重组,构建以像点实际值为待求量的非线性方程组;然后采用牛顿迭代法对影像中畸变部分进行局部线性逼近求解;最后采用间接重采样方法实现精确校正的目的。以移动机器人导航和避障相机作为研究对象,试验结果表明,牛顿迭代法校正可以得到高精度的优质去畸变影像,对避障相机的处理效果尤为显著。本文算法适用于移动机器人导航避障相机影像的畸变精确去除,为后续立体匹配环节生成优质的双目核线影像提供了可靠数据源。

高温条件下基于虚场法的钛合金弹塑性参数识别与提取

目的准确表述TC4钛合金的力学性能,对TC4钛合金进行了单轴热拉伸实验,使用虚场法识别和提取不同高温条件下TC4钛合金的弹塑性参数。方法在不同试验温度(650、700、750℃)下,选用TC4钛合金(Ti-6Al-4V合金),按轧制方向以应变速率为0.1 s^(-1)进行热拉伸试验。采用立体数字图像相关系统(DIC)测量试样的真实应变,得到真实应力-应变曲线,并捕捉热拉伸过程中的随机点,计算出试样的真实应变场。通过虚场法(VFM)在试件的弹性阶段设置不同虚拟位移场,建立虚场方程组以识别不同试验组中的弹性模量和泊松比,利用JC本构模型建立适合试件塑性变形阶段的虚场方程,使用K-Means聚类算法提取模型中的塑性参数。结果在考虑计算误差的情况下,使用VFM识别出的弹性模量、泊松比与参考数值的加权相对误差分别在4.8%、6.4%以下;提取出的塑性参数可以用于建立JC本构模型,弹塑性参数的识别和提取均符合预期。结论使用VFM可以有效识别出TC4在不同高温条件下的弹性参数,K-Means聚类算法在提取塑性参数方面的效果较为显著。

随机噪声平板下光学复眼内外参联合标定

光学复眼在无人系统的精确定位制导、避障导航等任务中得到了越来越广泛的应用,其中光学复眼的高精度标定是保障上述任务质量的前提。通常经典的张氏棋盘格标定法要求光学复眼的每个子眼都必须观测到完整的棋盘格,然而,由于光学复眼结构的复杂性,在实际标定过程中难以满足这一要求。为解决张氏标定法的局限性,该文提出一种基于随机噪声平板的光学复眼内外参联合标定算法,该算法通过子眼拍摄随机噪声平板的局部信息,可简单快速地实现任意构型和子眼数量的光学复眼内外参联合标定。为了提高光学复眼标定的稳定性,设置多阈值匹配机制解决子眼视场特征点数量稀疏导致图像匹配失效的问题。同时,给出了光学复眼内外参联合标定的误差模型,用来衡量所提出算法的精确度。在与张氏棋盘格标定法进行实验对比中,验证所提算法的稳定性和鲁棒性,并在光学复眼实物系统中,验证了所提联合标定算法具有较高的精度。

基于多域信息融合与深度分离卷积的轴承故障诊断网络模型

针对传统卷积神经网络(CNN)对滚动轴承振动信号的故障识别准确率不高这一问题,提出了一种基于多域信息融合结合深度分离卷积(MDIDSC)的轴承故障诊断方法。首先,利用自适应噪声的完全集合经验模态分解(CEEMDAN)算法对轴承振动信号进行了分解;然后,利用分解出的本征模态函数(IMF)的各个分量构建了多空间状态矩阵,并将该多空间状态矩阵输入该深度分离卷积模型中,进行了卷积训练;同时,在该深度分离卷积模型中添加了残差结构,对数据特征进行了复利用,并对卷积核进行了深度分离,解决了深度模型的网络退化问题;最后,提出了一种空间特征提取方法,对模型参数进行了修剪,采用一种自适应学习率退火方法进行了梯度优化,以避免模型陷入局部最优。研究结果表明:通过对多个轴承故障数据集进行对比分析可知,MDIDSC在轴承故障诊断方面的准确率和稳定性明显优于其他方法,MDIDSC的最高测试准确率为100%,平均测试准确率为99.07%;同时,在测试集中的最大损失和平均损失分别为0.1345和0.0841;该结果表明MDIDSC在轴承故障诊断方面具有一定的优越性。

基于2.5D标定扇的线阵相机内参数标定方法

针对工业生产线上或集成设备中线阵相机内参数定期检校困难且成本高的问题,提出一种基于2.5D标定扇的线阵相机内参数标定方法。设计了一款特定的2.5D标定扇,构建包含镜头畸变的线阵相机内参数标定模型,顾及了标靶相对相机的两个姿态角,通过方程线性变换法解算模型参数初值,利用改进的Levenberg-Marquardt(L-M)算法加速优化相机参数的求解过程,给出了详细的解算步骤和数据处理过程,并通过仿真和实测数据验证了方法的可行性。结果表明:该线阵相机标定方法简单灵活,可得到大量分布规律的特征点对,参数标定精度不受相机移动精度和特定移动方向的限制;在扇骨面与靶面间夹角小于10°时,可以获得高精度、高一致性的相机内参数,特征点重投影误差的最大值优于0.28 pixel,平均RMSE为0.11 pixel,标准差仅0.01 pixel。

类渐近线特性在摄像机标定中的应用研究

针对机器视觉领域内的摄像机标定,本研究首次根据渐近线的特性引入物理意义,对摄像机的内、外参数进行标定。首先使用6×6的圆孔标定板,计算出摄像机的投影矩阵。然后根据极限的定义,当像平面上投影点p(u,v)在v不变,u趋向正无穷时,光心与点p的连线形成类渐近线,该渐进线平行于摄像机坐标系XC轴,在标定时将其作为XC轴。根据这一特性,对得到的投影矩阵进行分解得到摄像机内、外参数。最后依据所提出的方法进行标定实验,得到摄像机投影矩阵以及相应的内、外参数。结果表明,根据该方法得到的标定数据反求特征点的投影坐标,与实际对应的图像特征点存在较小误差;并且得到的内、外参数与Faugeras标定法得到的结果误差较小,符合工程实际的精度要求。

SMA解锁装置设计与分析

为解决武器装备中载体和分离体之间的连接和分离问题,设计了一套SMA解锁装置。利用Brinson本构模型进行SMA驱动器设计,通过实验对SMA本构参数进行标定;针对分瓣螺母解除预紧力后的径向分离问题,设计了平面涡卷弹簧分离机构;利用ANSYS对分瓣螺母进行了连接强度校核以及装置的预应力模态仿真。结果表明,分瓣螺母在连接状态下不会产生塑性变形,随机振动情况下解锁装置不会发生误解锁。

矿用激光雷达与相机的无目标自动标定方法研究

矿用车辆实现无人驾驶依赖于准确的环境感知,激光雷达和相机的结合可以提供更丰富和准确的环境感知信息。为确保激光雷达和相机的有效融合,需进行外参标定。目前矿用本安型车载激光雷达多为16线激光雷达,产生的点云较为稀疏。针对该问题,提出一种矿用激光雷达与相机的无目标自动标定方法。利用多帧点云融合的方法获得融合帧点云,以增加点云密度,丰富点云信息;通过全景分割的方法提取场景中的车辆和交通标志物作为有效目标,通过构建2D-3D有效目标质心对应关系,完成粗校准;在精校准过程中,将有效目标点云通过粗校准的外参投影在逆距离变换后的分割掩码上,构建有效目标全景信息匹配度目标函数,通过粒子群算法最大化目标函数得到最优的外参。从定量、定性和消融实验3个方面验证了方法的有效性:(1)定量实验中,平移误差为0.055 m,旋转误差为0.394°,与基于语义分割技术的方法相比,平移误差降低了43.88%,旋转误差降低了48.63%。(2)定性结果显示,在车库和矿区场景中的投影效果与外参真值高度吻合,证明了该方法的稳定性。(3)消融实验表明,多帧点云融合和目标函数权重系数显著提高了标定精度。与单帧点云相比,使用融合帧点云作为输入时,平移误差降低了50.89%,旋转误差降低了53.76%;考虑权重系数后,平移误差降低了36.05%,旋转误差降低了37.87%。

基于毫米波雷达的智能车辆主动避障控制系统设计

智能车辆所搭载监测设备对障碍物目标的识别准确性,影响行驶车辆的避障能力;为避免车辆与障碍物发生碰撞,提升智能车辆的避障能力,设计基于毫米波雷达的智能车辆主动避障控制系统;在底层控制单元中,按需连接纵横向导航控制元件与毫米波雷达摄像头,完成智能车辆主动避障控制系统的部件结构设计;利用毫米波雷达监测所得的车辆避障图像,定义空间坐标系转换条件,通过标定雷达相机参数的方式,实现基于毫米波雷达的智能车辆避障路径规划;建立车辆纵横向运动模型,根据避障安全距离计算结果,完善具体控制流程,联合各级硬件应用结构,完成基于毫米波雷达的智能车辆纵横向主动避障控制系统的设计;实验结果表明,所设计系统可在智能车辆通过障碍物目标时,保证车体与障碍物之间的距离大于0.3 m,能够避免碰撞行为发生,对于车载监测设备而言,其对于障碍物目标的准确识别能力得到了保障,能够有效提升智能车辆避障能力。

改进TD3算法在电机PID控制器中的应用

本文针对永磁同步电机(PMSM)在工业领域中的多变量、非线性和强耦合特性以及传统PID控制在应对其变化时可能导致参数调整困难、响应延迟、鲁棒性差以及适应性问题,提出一种结合双延迟深度确定性策略梯度(TD3)算法和PID控制的创新方案,以优化PID参数调整,实现更精确的电机速度控制.在本文的方法中,融合双向长短期记忆网络(BiLSTM)到Actor和Critic网络中,极大增强了对PMSM动态行为的时间序列数据处理能力,使得系统不仅能够准确捕捉当前状态,还能预测未来趋势,从而实现对PID参数更精确和适应性强的自整定.此外,通过整合熵正则化和好奇心驱动的探索方法进一步增强策略的多样性,避免过早收敛到次优策略,并鼓励模型对未知环境进行深入探索.为验证方法的有效性,设计了一个永磁同步电机的仿真模型,并将本文提出的方法BiLSTM-TD3-ICE与传统的TD3以及经典的Ziegler-Nichols (Z-N)方法进行对比.实验结果充分证明了本文提出的策略在控制性能上具有显著的优势.

改进遗传算法优化的温室移动机器人单目相机标定

目的:针对温室移动机器人领域传统的张正友相机标定方法存在相机内参数的求解可能陷入局部最优解的问题,使用一种基于改进遗传算法的单目相机内参数优化方案。方法:首先使用张正友标定法得到初始的内参值,然后引入改进的遗传算法对内参初始值进行优化,最后将优化后的内参值代入相机成像模型,得到优化后的重投影误差。结果:将本算法优化后的重投影误差与标准算法和张正友标定法得到的进行比较,证明本研究标定的单目像机内部参数更加准确,标定速度和稳定性更好。结论:改进遗传算法平均重投影误差低于标准算法和张正友标定法,且图像主点坐标更接近参考值,能较好地缓解过早收敛和停滞现象,提高了标定精度,在温室移动机器人视觉应用系统中,本方法有较强的的实用价值。