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1.
针对生化反应过程中软测量模型随着时间的推移而出现的模型老化现象,提出一种基于增量学习的自适应模糊支持向量机软测量建模方法.它首先将输入空间中的样本映射到高维特征空间,然后根据样本偏离超平面的程度赋予不同的模糊隶属度,建立模糊支持向量机软测量模型,并在模型投入现场运行后,通过一种改进的增量学习算法在线更新模型参数以自适应获得更加准确的软测量模型.以L-赖氨酸流加发酵过程为例,验证了所提算法能够从过程的第2批次开始对关键生物量参数(菌丝浓度和基质浓度)进行较准确的在线预测,与普通的模糊支持向量机建模方法相比具有较高的预测精度和自适应性.  相似文献   

2.
流程工业数据具有较大的时变性以及非线性,传统的离线模型难以应对实际生产过程中的工况变化,而即时学习是在线建模的有效方法。已有研究对即时学习的相似度度量方法大多只侧重于样本的空间距离,忽略了工业数据时序性的特点。为此,提出基于时空相似性的即时学习建模方法。首先,将样本点延拓成样本序列,结合动态时间规整计算样本间的时序距离。其次,提出时空相似性度量准则,通过对时序距离和空间距离进行非线性加权,构建时空相似性度量指标。最后,提出基于时空相似性的即时学习在线建模方法。将所提算法应用于公共数据集及聚酯纤维聚合过程,拟合优度分别达到了91.6%和98.6%,实验结果验证了算法的有效性和优越性。  相似文献   

3.
基于AWLS-SVM的污水处理过程软测量建模   总被引:3,自引:0,他引:3       下载免费PDF全文
针对污水处理过程建模中样本数据可能存在的测量误差对模型性能的影响,提出一种自适应加权最小二乘支持向量机(AWLS-SVM)回归的软测量建模方法。该方法基于最小二乘支持向量机模型,根据样本拟合误差,并结合改进的指数分布赋权规则,自适应地为每个建模样本分配不同的权值,以降低随机误差对模型性能的影响;同时采用一种全局优化算法——混沌粒子群模拟退火(CPSO-SA)算法对最小二乘支持向量机的模型参数进行优化选择,以提高模型的泛化能力。仿真实验表明,AWLS-SVM模型的预测精度及鲁棒性能优于LS-SVM和WLS-SVM。最后,应用AWLS-SVM方法建立污水处理过程出水水质关键参数的软测量模型,获得了较好的效果。  相似文献   

4.
针对甲醇生产过程中高度的非线性和时变性,采用精确在线支持向量机模型预测粗甲醇的转化率。在线支持向量机模型一般采用单一的核函数,混合核函数可以弥补单一核函数的不足,提高模型的泛化能力和学习能力。为了使模型的预测精度进一步提高,在混合核函数的基础上运用在线误差校正方法。将基于混合核函数和误差校正的在线支持向量机建模方法应用在煤制甲醇数据上,通过与传统支持向量机和准确在线支持向量机模型对比,仿真实验和分析结果表明改进的在线支持向量机模型比传统支持向量机预测精度高,能够实现粗甲醇转化率的实时预测,从而更好的指导甲醇生产。  相似文献   

5.
多元校正分析模型的精度不仅依赖于模型的结构和参数,还很大程度上取决于训练样本的分布。实际过程中,训练样本通常呈现不均匀分布,导致基于全体样本的回归模型预测性能不理想。本文针对该问题提出了支持向量机分类与回归联合建模方法:首先使用最小二乘支持向量机(LS-SVM)分类器构建分类决策树,然后对每一类样本分别建立最小二乘支持向量机回归模型;对未知样本进行定量分析时,首先经过分类决策树分类,再根据分类信息选择相应的回归模型进行计算。针对汽油辛烷值拉曼光谱分析问题,基于全体样本建模的LS-SVM回归模型的标准预测误差为0.54,而采用本文方法所得的模型预测误差为0.22,大幅度地提高了分析精度。  相似文献   

6.
基于SVM的船舶动力定位系统预测控制   总被引:1,自引:0,他引:1  
支持向量机(SVM)是基于统计学习理论的新一代机器学习技术。基于预测控制思想,利用支持向量机回归进行非线性系统辨识,并将支持向量机模型应用到船舶动力定位(DP)预测控制,提出一种基于支持向量机的非线性系统预测控制策略。仿真实验表明,支持向量机在小样本情况下具有良好的非线性建模能力和泛化能力,预测控制效果良好。  相似文献   

7.
基于最小二乘支持向量机的发酵过程混合建模   总被引:7,自引:5,他引:7  
提出了一种综合先验知识与最小二乘支持向量机的发酵过程建模方法,并且采用遗传算法进行最小二乘支持向量机的参数优化选取。该模型应用到一个具体发酵过程状态变量的预估中,仿真结果表明基于最小二乘支持向量机的混合模型具有很高的精度与范化能力,同时也表明了最小二乘支持向量机是软测量建模的一种有效方法。  相似文献   

8.
针对裂纹扩展是一个典型的非线性、随机过程,且裂纹数据样本少、获取困难等问题,提出一种基于灰色支持向量机的裂纹扩展预测模型。首先通过灰色模型对原始序列进行数据生成,以增强数据的规律性;然后选择合适的核函数,并用试验数据修正核函数;最后用支持向量机进行预测,并还原数据,得到预测结果。将其应用于某航天发射塔架裂纹扩展预测中,并与灰色模型、单一支持向量机、最小二乘支持向量机进行预测性能对比,结果表明,灰色支持向量机预测性能最优。同时也为裂纹扩展预测及提高预测性能提供一种新途径。  相似文献   

9.
支持向量机是建立在统计学理论之上的强有力的机器学习技术。本文提出了基于支持向量机模型预测钢淬透性的方法,并分析了核函数的选择对支持向量机建模的影响。以江阴兴澄钢铁公司的实际数据进行实验,结果表明,支持向量机方法有着良好的泛化能力,优于人工神经网络建模方法。  相似文献   

10.
影响电力需求的因素很多,单一预测方法很难满足不同情况的预测需要,而现有组合预测模型又主要基于经验风险最小,预测精度受组合模型的限制。本文提出一种基于支持向量机的电力负荷组合预测模型,该模型利用结构风险最小化原则代替传统的经验风险最小化,充分挖掘原始数据和单一预测模型的信息,以单一模型的预测数据为预测样本,选择多项式函数支持向量机进行组合预测。实际算例表明,支持向量机法克服了传统神经网络算法的局部最优、收敛难以控制等缺点,具有良好的可行性和有效性。  相似文献   

11.
A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.  相似文献   

12.
针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。  相似文献   

13.
针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。  相似文献   

14.
交通荷载作用下桥梁结构参数识别方法   总被引:2,自引:1,他引:1  
应用动力节点加载法,将作用在桥梁上的交通荷载转化为等效节点荷载,再用两步构造法识别结构物理参数.第1步,用Newmark-β方法变换结构运动方程,并用结构的加速度响应求得变换空间内的位移、速度和加速度响应;第2步,基于最小二乘原理,构造出变换空间内求解结构参数的递推式,进行结构物理参数识别.数值模拟结果表明,在交通荷载作用下,该方法能够快速、准确地进行桥梁结构参数识别.  相似文献   

15.
The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...  相似文献   

16.
黑棣  郑美茹 《机电工程》2016,(11):1315-1321
针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。  相似文献   

17.
RLS and LMS blind adaptive multi-user detection algorithm and multi-user detector was proposed to solve the problem of multi-user signal detection problem encountered in underwater acoustic communication networks.In simulation analysis,RLS and the LMS blind adaptive multi-user detector were designed and tested for synchronous and asynchronous multi-user communication process.The results of SIR comparison and MMSE comparison show that,both of the two methods can realize blind adaptive detection when any user change in multi-user communication,during this process,the training communication sequences are not needed.The RLS algorithm has about 5 dB higher in SIR compared with LMS algorithm,and the convergence velocity of RLS algorithm is also higher than LMS algorithm when the communication users change.RLS algorithm has better ability in multi-user detection than that of LMS algorithm,and it has great attraction and guiding significance for solving the problem of multiple access interference(MAI) in multi-user communication.  相似文献   

18.
For robot interaction control,the interaction force between the robot and the manipulated object or environment should be monitored.Impedance control is a type ...  相似文献   

19.
This paper analysis the developing of expendable conductivity temperature depth measuring system(XCTD)and introduce its principle of measuring about temperature,salinity and depth of ocean.Some key techniques are put forward.According to the real needs of XCTD,conductivity sensor with high sensitivity is designed by principle of electromagnetic induce,the ocean conductivity from induced electromotive force has been calculated.Adding temperature correction circuit would help to reduce error of conductivity measurement because of sharply changing temperature.Advanced temperature measuring circuit of high precision and the constant current source is used to weaken effect of self-heating of resistance and fluctuation of the source.On respect of remote data transmission,LVDS is a good choice for the purpose of guarantee the quality of data transmitted and the transmission distance is reaching to thousand meters in the seawater.Modular programming method is also brought into this research aimed at improve the stability,reliability and maintainability of the whole measuring system.In February,2015,the trials in South China Sea demonstrate that the developed XCTD realize effective measurement at a speed of 6 knots and detection depth at 800 m.The consistency coefficient of the acquired data is greater than 0.99 and the success rate of probe launching is above 90%.  相似文献   

20.
In order to investigate the sealing performance variation resulted from the thermal deformation of the end faces, the equations to calculate the fluid film pressure distribution, the bearing force and the leakage rate are derived, for the fluid film both in parallel gap and in wedgy gap. The geometrical parameters of the sealing members are optimized by means of heat transfer analysis and complex method. The analysis results indicate that the shallow spiral grooves can generate hydrodynamic pressure while the rotating ring rotates and the bearing force of the fluid film in spiral groove end faces is much larger than that in the flat end faces. The deformation increases the bearing force of the fluid film in flat end faces, but it decreases the hydrodynamic pressure of the fluid film in spiral groove end faces. The gap dimensions which determine the characteristics of the fluid film is obtained by coupling analysis of the frictional heat and the thermal deformation in consideration of the equilibrium condition of the bearing force and the closing force. For different gap dimensions, the relationship between the closing force and the leakage rate is also investigated, based on which the leakage rate can be controlled by adjusting the closing force.  相似文献   

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