基于IECSDE算法的PEMFC改进分数阶子空间辨识模型

为准确描述质子交换膜燃料电池(PEMFC)在其发电过程中的特性及变量影响关系,提出一种基于信息交流布谷鸟搜索差分进化(IECSDE)算法的改进分数阶子空间辨识方法来建立PEMFC分数阶模型。首先基于状态空间方程建立PEMFC模型,为了描述PEMFC的分数阶特性,将分数阶微分理论融入到模型中,引入Poisson滤波函数预处理实验数据,解决数据多阶不可导的问题,同时引入变步长记忆法处理分数阶微分时的权系数,提高子空间辨识精度。其次在辨识过程中的参数对于建模效果具有重大影响,因此基于IECSDE算法并对其进行优化,对布谷鸟搜索(CS)算法中的控制参数进行自适应处理,受到粒子群优化(PSO)算法的启发,改进随机游走方式提高收敛精度和速度,并引入差分进化(DE)算法与改进CS算法分别对种群进行优化,同时在寻优过程中进行信息交流提高种群的多样性和算法的鲁棒性。仿真结果表明,IECSDE算法的寻优能力在8种测试函数下比其他5种优化算法至少提升了10倍;通过对PEMFC测控平台收集到的实验数据进行模型辨识,所建立的模型将误差缩小到基于短记忆法的分数阶子空间辨识方法误差的20%,输出功率误差控制在0~0.1之间,输出电压误差控制在0~0.2之间,能够精准地模拟PEMFC发电过程。

Novel Model of Proton Exchange Membrane Fuel Cell with Predictive Control Using Hildreth Algorithm Based on Fractional-order Dynamic Model

Considering the multivariable and fractional-order characteristics of proton exchange membrane fuel cells(PEMFCs),a fractional-order subspace identification method(FOSIM)is proposed in this paper to establish a fractionalorder state space(FOSS)model,which can be expressed as a multivariable configuration with two inputs,hydrogenflow rate and stack current,and two outputs,cell voltage and power.Based on this model,a novel constrained optimal control law named the Hildreth model predictive control(H-MPC)strategy is created,which employs a Hildreth quadratic programming algorithm to adjust the output power of fuel cells through adaptively regulating hydrogen flow and stack current.dSPACE semi-physical simulation results demonstrate that,compared with proportional-integral-derivative and quadratic programming MPC(QP-MPC),the proposed H-MPC exhibits better tracking ability and strong robustness against variations of PEMFC power.

基于ALMBO算法的PEMFC分数阶时域子空间模型研究

针对质子交换膜燃料电池(PEMFC)发电过程复杂难以建模的问题,考虑PEMFC系统的分数阶特性,提出一种基于优化的分数阶时域子空间辨识方法,并建立PEMFC的分数阶状态空间模型。首先,将分数阶微分理论与子空间时域辨识方法相结合,采用Poisson滤波器对输入输出信号进行滤波处理,并引入权重矩阵提高辨识的精度;其次,对Poisson滤波器以及辨识的分数阶阶次寻优,提出一种变异反向学习的自适应帝王蝶优化算法(ALMBO),在迁移算子中引入变异反向学习策略、并融入自适应权重来提高寻优的精度,防止陷入局部最优解。最后,通过仿真结果验证算法的有效性,所得的PEMFC辨识模型能准确描述PEMFC的动态过程。

机械臂的位姿分离求逆和改进RRT-connect算法研究

针对机械臂逆解求取过程中存在大量矩阵变换、计算成本高的问题,采用位姿分离法对逆运动学求解过程进行改进,并提出基于自适应步长的RRT-connect路径规划算法。首先建立六自由度机械臂连杆坐标系模型,采用Standard Denavit-Hartenberg(D-H)方法对机械臂进行正运动学分析,得到机械臂末端执行器位姿相对于基座的齐次变换矩阵。然后引入位姿分离法改进了机械臂的逆运动学求解方法,将机械臂运动学逆解分为位置逆解和姿态逆解两部分,分别用几何法和解析法进行求解,减少了整体计算量。再者提出基于自适应步长的改进RRT-connect路径规划算法,解决了扩展速度慢的问题。最后通过仿真验证所提出方法的正确性和有效性。

PEMFC Identification Based on a Fractional-Order Hammerstein State-Space Model with ADE-BH Optimization

Considering the fractional-order and nonlinear characteristics of proton exchange membrane fuel cells(PEMFC),a fractional-order subspace identification method based on the ADE-BH optimization algorithm is proposed to establish a fractional-order Hammerstein state-space model of PEMFCs.Herein,a Hammerstein model is constructed by connecting a linear module and a nonlinear module in series to precisely depict the nonlinear property of the PEMFC.During the modeling process,fractional-order theory is combined with subspace identification,and a Poisson filter is adopted to enable multi-order derivability of the data.A variable memory method is introduced to reduce computation time without losing precision.Additionally,to improve the optimization accuracy and avoid obtaining locally optimum solutions,a novel ADEBH algorithm is employed to optimize the unknown parameters in the identification method.In this algorithm,the Euclidean distance serves as the theoretical basis for updating the target vector in the absorption-generation operation of the black hole(BH)algorithm.Finally,simulations demonstrate that the proposed model has small output error and high accuracy,indicating that the model can accurately describe the electrical characteristics of the PEMFC process.

感染的非抗菌药物治疗策略

感染性疾病的死亡率仍然居高不下,这是由于重症患者在前期治疗中已经使用广谱抗菌药物;抗菌药物不合理应用导致细菌耐药率明显上升,治疗中需要不断增加剂量,抗菌药物的不良反应随之增加;即使抗菌药物应用合理,也不能完全阻止感染导致的组织器官损伤和多脏器功能衰竭。感染的发生,需要病原体通过传播途径侵害易感人群。对于感染性疾病,如果能够减弱致病微生物毒力、降低人群易感性也可以起到抗感染的作用。同时,人体作为有机整体,对整体进行支持治疗也是抗感染治疗的重要组成部分,感染的治疗应该抗菌药物与非抗菌药物方法并重,方可收到事半功倍的效果。

基于分数阶PID控制的质子交换膜燃料电池前级功率变换器

针对质子交换膜燃料电池(PEMFC)输出为大电流、宽电压而难以实际应用的问题,首先提出一种以四开关Buck-Boost变换器为主拓扑的PEMFC预稳压模块,采用双沿开关管触发策略减小电感电流脉动,并基于高频开关网络等效原理建立准确的动态模型;然后设计一种分数阶PID控制器实现模块的稳压补偿,并采用一种随机惯性权重PSO算法整定控制器的参数。仿真与实验结果表明,与整数阶控制器相比,分数阶PID控制器具有更好的补偿效果,在系统参数或结构变化时表现出较强的鲁棒性,所提出的模块具有高效可靠的预稳压功能。

基于电荷泵的燃料电池有源网络升压变换器

高增益DC-DC变换器是燃料电池发电技术的关键环节,有利于改善燃料电池小电压、大电流特性。但是由于传统Boost变换器存在电压增益有限、电感电流纹波大、功率器件应力高的缺陷,无法满足燃料电池发电系统并网运行的需求。该文提出一种基于电荷泵的燃料电池有源网络升压变换器,将有源网络变换器中输入侧的电感用电荷泵结构代替。该变换器结合电荷泵电压倍增能力强和有源网络结构输入电流纹波小的优势,具有电压增益高、电感电流平均值小、开关器件电压/电流应力低、鲁棒性强的特点。最后搭建一套燃料电池前级功率变换实验样机,验证了变换器的高效率与有效性,当输入电压为20V、输出电流为1.25A时,系统整体效率可以达到94.1%。

变异反向学习的自适应帝王蝶优化算法

针对于原始帝王蝶优化算法易陷入局部最优解、收敛性不好等问题,提出变异反向学习的自适应帝王蝶优化算法。将遗传算法的变异思想与反向学习策略结合来替代原始的迁移算子,提高全局的收敛性。在原始帝王蝶优化算法的调整算子中融入自适应的策略,使种群更具多样性。在更新的种群中将排序在最后的5只帝王蝶进行柯西变异,让变异个体附近生成更大的扰动,使整个群体在更大的范围内进行寻优。为了验证改进帝王蝶优化算法,通过基准函数和Wilcoxon秩和检验对其进行测试,实验结果表明改进算法的收敛速度及寻优精度得到了很大改进。

Improved quantum bacterial foraging algorithm for tuning parameters of fractional-order PID controller

The quantum bacterial foraging optimization(QBFO)algorithm has the characteristics of strong robustness and global searching ability. In the classical QBFO algorithm, the rotation angle updated by the rotation gate is discrete and constant,which cannot affect the situation of the solution space and limit the diversity of bacterial population. In this paper, an improved QBFO(IQBFO) algorithm is proposed, which can adaptively make the quantum rotation angle continuously updated and enhance the global search ability. In the initialization process, the modified probability of the optimal rotation angle is introduced to avoid the existence of invariant solutions. The modified operator of probability amplitude is adopted to further increase the population diversity.The tests based on benchmark functions verify the effectiveness of the proposed algorithm. Moreover, compared with the integerorder PID controller, the fractional-order proportion integration differentiation(PID) controller increases the complexity of the system with better flexibility and robustness. Thus the fractional-order PID controller is applied to the servo system. The tuning results of PID parameters of the fractional-order servo system show that the proposed algorithm has a good performance in tuning the PID parameters of the fractional-order servo system.

Parameter identification of the fractional-order systems based on a modified PSO algorithm

In order to better identify the parameters of the fractional-order system,a modified particle swarm optimization(MPSO)algorithm based on an improved Tent mapping is proposed.The MPSO algorithm is validated with eight classical test functions,and compared with the POS algorithm with adaptive time varying accelerators(ACPSO),the genetic algorithm(GA),a d the improved PSO algorithm with passive congregation(IPSO).Based on the systems with known model structures a d unknown model structures,the proposed algorithm is adopted to identify two typical fractional-order models.The results of parameter identification show that the application of average value of position information is beneficial to making f 11 use of the information exchange among individuals and speeds up the global searching speed.By introducing the uniformity and ergodicity of Tent mapping,the MPSO avoids the extreme v^ue of position information,so as not to fall into the local optimal value.In brief the MPSOalgorithm is an effective a d useful method with a fast convergence rate and high accuracy.

PEMFC Fractional-order Subspace Identification Model

A proton exchange membrane fuel cell(PEMFC)is a new type of hydrogen fuel cell that plays an indispensable role in an energy network.However,the multivariable and fractional-order characteristics of PEMFC make it difficult to establish a practical model.Herein,a fractional-order subspace identification model based on the adaptive monarch butterfly optimization algorithm with opposition-based learning(ALMBO)algorithm is proposed for PEMFC.Introducing the fractional-order theory into the subspace identification method by adopting a Poisson filter for with input and output data,a weight matrix is proposed to improve the identification accuracy.Additionally,the ALMBO algorithm is employed to optimize the parameters of the Poisson filter and fractional order,which introduces an opposition-based learning strategy into the migration operator and incorporates adaptive weights to improve the optimization accuracy and prevent falling into a locally optimal solution.Finally,the PEMFC fractional-order subspace identification model is established,which can accurately describe the dynamic process of PEMFC.

250例农村地区女性性工作者生殖道沙眼衣原体感染现状和相关因素分析

目的分析农村地区女性性工作者生殖道沙眼衣原体的感染情况,并探讨相关的危险因素。方法在广东省云浮市农村地区采用方便抽样法招募250例女性性工作者。采用问卷调查收集一般人口学特征和性行为学特征。采集静脉血进行梅毒和HIV的检测,采集尿液利用荧光聚合酶链式反应检测淋球菌和沙眼衣原体。结果生殖道沙眼衣原体的感染率为22.00%(55/250),淋球菌感染率为11.60%(29/250),梅毒感染率为0.80%(2/250),无HIV感染。55例衣原体感染人群中,淋球菌感染率为40.00%,无梅毒感染者。月收入越低(OR=3.052)、教育程度越低(OR=2.611)、最近一个月不持续使用安全套(OR=3.226)和平均每周性伴数量越多(OR=2.109)者生殖道沙眼衣原体感染越高。结论农村地区的女性性工作者生殖道沙眼衣原体感染率较高,建议加强对农村地区女性性工作者生殖道沙眼衣原体的检测和健康宣教,提高自我防控风险意识。

云浮市农村地区育龄妇女生殖道沙眼衣原体感染现状调查

目的探究云浮市农村地区育龄妇女生殖道沙眼衣原体(CT)感染现状并分析其影响因素。方法2022年8月-2022年12月在云浮市4家医院招募性病就诊农村地区育龄妇女300例,采用问卷调查收集患者社会人口学特征、性行为史、CT感染史、性病实验室检测结果等,分析育龄妇女CT感染影响因素。结果此次招募育龄妇女中问卷填写完整者287例,问卷回收率95.67%,其中发生CT感染者23例,感染率为8.01%;相较于年龄>30岁、已婚、使用安全套、近1年无性病症状、既往无淋球菌感染史、接受过性病相关健康宣教及近1年无盆腔炎病史的育龄妇女,年龄≤30岁、非已婚、从没使用安全套、近1年有性病症状、既往存在淋球菌感染史、未接受过性病相关健康宣教及近1年有盆腔炎病史的育龄妇女生殖道CT感染率明显较高(P<0.05);非已婚、近半年性行为从没使用过安全套、既往存在淋球菌感染史、既往从未接受性病相关健康宣教是育龄妇女生殖道CT感染的危险因素(P<0.05)。结论云浮市农村地区育龄妇女生殖道CT感染率较高,应针对30岁及以下、非已婚、既往存在淋球菌感染史的女性就诊者开展CT常规筛查,提高农村女性对安全性行为、CT基本知识及不良后果的知晓率。