Rapidly-exploring Random Tree(RRT)and its variants have become foundational in path-planning research,yet in complex three-dimensional off-road environments their uniform blind sampling and limited safety guarantees l...Rapidly-exploring Random Tree(RRT)and its variants have become foundational in path-planning research,yet in complex three-dimensional off-road environments their uniform blind sampling and limited safety guarantees lead to slow convergence and force an unfavorable trade-off between path quality and traversal safety.To address these challenges,we introduce HS-APF-RRT*,a novel algorithm that fuses layered sampling,an enhanced Artificial Potential Field(APF),and a dynamic neighborhood-expansion mechanism.First,the workspace is hierarchically partitioned into macro,meso,and micro sampling layers,progressively biasing random samples toward safer,lower-energy regions.Second,we augment the traditional APF by incorporating a slope-dependent repulsive term,enabling stronger avoidance of steep obstacles.Third,a dynamic expansion strategy adaptively switches between 8 and 16 connected neighborhoods based on local obstacle density,striking an effective balance between search efficiency and collision-avoidance precision.In simulated off-road scenarios,HS-APF-RRT*is benchmarked against RRT*,GoalBiased RRT*,and APF-RRT*,and demonstrates significantly faster convergence,lower path-energy consumption,and enhanced safety margins.展开更多
由于微电网中分布式电源的间歇性、非线性负荷增减频繁等原因,导致谐波能量变化较大,采用多台并联运行的有源电力滤波器APF(active power filter)能够对微电网谐波进行有效治理。然而,多台APF并联运行会因各APF补偿的电流不均而形成环流...由于微电网中分布式电源的间歇性、非线性负荷增减频繁等原因,导致谐波能量变化较大,采用多台并联运行的有源电力滤波器APF(active power filter)能够对微电网谐波进行有效治理。然而,多台APF并联运行会因各APF补偿的电流不均而形成环流,从而导致系统损耗增加。为此,本文提出1种基于电能信息一体化传输技术的均流控制方法,通过在逆变器功率调制环节加入信息调制,实现电能变换的同时传递关键信息,完成并联系统的均流控制。相较于传统的集中式、主从式控制方法,本文提出的方法无需额外的通信设备和通信线路,可进一步提高系统的可靠性、灵活性和可扩展性。通过RT-LAB仿真实验验证了所提均流控制方法的可行性与有效性。展开更多
Actinobacillus pleuropneumoniae(APP)is the major pathogen of porcine contagious pleuropneumoniae(PCP).The QseB/QseC two-component system(TCS)consists of the regulator QseB and the kinase QseC,which relates to quorum s...Actinobacillus pleuropneumoniae(APP)is the major pathogen of porcine contagious pleuropneumoniae(PCP).The QseB/QseC two-component system(TCS)consists of the regulator QseB and the kinase QseC,which relates to quorum sensing(QS)and virulence in some bacteria.Here,we investigated the role of QseB/QseC in apf gene cluster(apfABCD)expression of APP.Our results have showed that QseB/QseC TCS can potentially regulate the expression of apf gene cluster.The△qseBC,△apfA,△apfB,△apfC and△apfD strains are more sensitive to acidic and osmotic stressful conditions,and exhibite lower biofilm formation ability than wild-type(WT)strain,whereas the complemented strains show similar phenotype to the wr strain.In additon,the mutants have defective antiphagocytosis,adhesion and invasion when they come into contact with the host cells.In experimental animal models of infection,mice infected with△qseBC,△apfA,△apfB,△apfC and △apfD strains showed lower mortality and bacterial loads in the lung and the blood than those infected with wr strain.In conclusion,our results suggest that QseB/QseC TCS contributes to stress resistance,biofilm formation,phagocytosis,adhesion,invasion and virulence by downregulating expression of apf gene cluster in A.pleuropneumoniae.展开更多
可再生能源并网日益增加对电力系统的稳定性和电能质量提出了更高的挑战。有源滤波器(active power filter,APF)作为一种抑制谐波和进行无功补偿的电能质量调节器,其性能与拓扑结构和信号估计方法密不可分。首先根据拓扑结构对APF进行...可再生能源并网日益增加对电力系统的稳定性和电能质量提出了更高的挑战。有源滤波器(active power filter,APF)作为一种抑制谐波和进行无功补偿的电能质量调节器,其性能与拓扑结构和信号估计方法密不可分。首先根据拓扑结构对APF进行了分类,其次分析了APF信号估计传统方法的优缺点,在此基础上提出基于变分模态分解算法与卡尔曼滤波算法的变分卡尔曼滤波算法对谐波信号进行估计,最后对变分卡尔曼滤波算法的应用效果进行了仿真验证,结果显示该算法能有效抑制谐波电流,提高电能质量。展开更多
很多工业企业因为负荷的原因导致电能质量很差,对自己的生产造成影响的同时也对公共电网造成污染。APF设备不仅可以治理企业自身的电能质量,同时也会给企业的节能降耗带来经济效益,帮助企业绿色低碳转型和高质量发展。APF(Active Power ...很多工业企业因为负荷的原因导致电能质量很差,对自己的生产造成影响的同时也对公共电网造成污染。APF设备不仅可以治理企业自身的电能质量,同时也会给企业的节能降耗带来经济效益,帮助企业绿色低碳转型和高质量发展。APF(Active Power Filter有源电力滤波器)。展开更多
由于电力有源滤波器(active power filter,APF)快速跟踪消除谐波的特点,其被大量安装在配电网以保证配电网安全可靠运行。然而,随着APF装置大量无序接入配电网,其交互影响现象无法忽视。针对配电网内APF之间交互影响问题,以典型并联双AP...由于电力有源滤波器(active power filter,APF)快速跟踪消除谐波的特点,其被大量安装在配电网以保证配电网安全可靠运行。然而,随着APF装置大量无序接入配电网,其交互影响现象无法忽视。针对配电网内APF之间交互影响问题,以典型并联双APF系统作为研究对象,计及单APF系统稳态误差,基于等效输出阻抗法,建立了并联双APF等效模型。研究了电气及控制参数与并联双APF系统内在联系,分析了弱电网背景下一个APF的系统稳态误差对另一个APF运行稳定性的影响,继而从控制理论角度揭示了双APF并联交互影响原理,提出了抑制交互影响的措施。最后仿真验证了上述理论分析的正确性。展开更多
基金supported in part by 14th Five Year National Key R&D Program Project(Project Number:2023YFB3211001)the National Natural Science Foundation of China(62273339,U24A201397).
文摘Rapidly-exploring Random Tree(RRT)and its variants have become foundational in path-planning research,yet in complex three-dimensional off-road environments their uniform blind sampling and limited safety guarantees lead to slow convergence and force an unfavorable trade-off between path quality and traversal safety.To address these challenges,we introduce HS-APF-RRT*,a novel algorithm that fuses layered sampling,an enhanced Artificial Potential Field(APF),and a dynamic neighborhood-expansion mechanism.First,the workspace is hierarchically partitioned into macro,meso,and micro sampling layers,progressively biasing random samples toward safer,lower-energy regions.Second,we augment the traditional APF by incorporating a slope-dependent repulsive term,enabling stronger avoidance of steep obstacles.Third,a dynamic expansion strategy adaptively switches between 8 and 16 connected neighborhoods based on local obstacle density,striking an effective balance between search efficiency and collision-avoidance precision.In simulated off-road scenarios,HS-APF-RRT*is benchmarked against RRT*,GoalBiased RRT*,and APF-RRT*,and demonstrates significantly faster convergence,lower path-energy consumption,and enhanced safety margins.
文摘由于微电网中分布式电源的间歇性、非线性负荷增减频繁等原因,导致谐波能量变化较大,采用多台并联运行的有源电力滤波器APF(active power filter)能够对微电网谐波进行有效治理。然而,多台APF并联运行会因各APF补偿的电流不均而形成环流,从而导致系统损耗增加。为此,本文提出1种基于电能信息一体化传输技术的均流控制方法,通过在逆变器功率调制环节加入信息调制,实现电能变换的同时传递关键信息,完成并联系统的均流控制。相较于传统的集中式、主从式控制方法,本文提出的方法无需额外的通信设备和通信线路,可进一步提高系统的可靠性、灵活性和可扩展性。通过RT-LAB仿真实验验证了所提均流控制方法的可行性与有效性。
基金supported by grants from the Technique Innovation Program of Hubei Province(No.2018ABA108)the National Pig Industry Technology System(No.CARS-35).
文摘Actinobacillus pleuropneumoniae(APP)is the major pathogen of porcine contagious pleuropneumoniae(PCP).The QseB/QseC two-component system(TCS)consists of the regulator QseB and the kinase QseC,which relates to quorum sensing(QS)and virulence in some bacteria.Here,we investigated the role of QseB/QseC in apf gene cluster(apfABCD)expression of APP.Our results have showed that QseB/QseC TCS can potentially regulate the expression of apf gene cluster.The△qseBC,△apfA,△apfB,△apfC and△apfD strains are more sensitive to acidic and osmotic stressful conditions,and exhibite lower biofilm formation ability than wild-type(WT)strain,whereas the complemented strains show similar phenotype to the wr strain.In additon,the mutants have defective antiphagocytosis,adhesion and invasion when they come into contact with the host cells.In experimental animal models of infection,mice infected with△qseBC,△apfA,△apfB,△apfC and △apfD strains showed lower mortality and bacterial loads in the lung and the blood than those infected with wr strain.In conclusion,our results suggest that QseB/QseC TCS contributes to stress resistance,biofilm formation,phagocytosis,adhesion,invasion and virulence by downregulating expression of apf gene cluster in A.pleuropneumoniae.
文摘可再生能源并网日益增加对电力系统的稳定性和电能质量提出了更高的挑战。有源滤波器(active power filter,APF)作为一种抑制谐波和进行无功补偿的电能质量调节器,其性能与拓扑结构和信号估计方法密不可分。首先根据拓扑结构对APF进行了分类,其次分析了APF信号估计传统方法的优缺点,在此基础上提出基于变分模态分解算法与卡尔曼滤波算法的变分卡尔曼滤波算法对谐波信号进行估计,最后对变分卡尔曼滤波算法的应用效果进行了仿真验证,结果显示该算法能有效抑制谐波电流,提高电能质量。
文摘由于电力有源滤波器(active power filter,APF)快速跟踪消除谐波的特点,其被大量安装在配电网以保证配电网安全可靠运行。然而,随着APF装置大量无序接入配电网,其交互影响现象无法忽视。针对配电网内APF之间交互影响问题,以典型并联双APF系统作为研究对象,计及单APF系统稳态误差,基于等效输出阻抗法,建立了并联双APF等效模型。研究了电气及控制参数与并联双APF系统内在联系,分析了弱电网背景下一个APF的系统稳态误差对另一个APF运行稳定性的影响,继而从控制理论角度揭示了双APF并联交互影响原理,提出了抑制交互影响的措施。最后仿真验证了上述理论分析的正确性。
