This paper presents the rigorous study of mobile robot navigation techniques used so far.The step by step investigations of classical and reactive approaches are made here to understand the development of path plannin...This paper presents the rigorous study of mobile robot navigation techniques used so far.The step by step investigations of classical and reactive approaches are made here to understand the development of path planning strategies in various environmental conditions and to identify research gap.The classical approaches such as cell decomposition(CD),roadmap approach(RA),artificial potential field(APF);reactive approaches such as genetic algorithm(GA),fuzzy logic(FL),neural network(NN),firefly algorithm(FA),particle swarm optimization(PSO),ant colony optimization(ACO),bacterial foraging optimization(BFO),artificial bee colony(ABC),cuckoo search(CS),shuffled frog leaping algorithm(SFLA)and other miscellaneous algorithms(OMA)are considered for study.The navigation over static and dynamic condition is analyzed(for single and multiple robot systems)and it has been observed that the reactive approaches are more robust and perform well in all terrain when compared to classical approaches.It is also observed that the reactive approaches are used to improve the performance of the classical approaches as a hybrid algorithm.Hence,reactive approaches are more popular and widely used for path planning of mobile robot.The paper concludes with tabular data and charts comparing the frequency of individual navigational strategies which can be used for specific application in robotics.展开更多
The photo-reactions between metabolic products of human sweat and dyestuffs on garments may produce many toxic substances which could directly contact skin and threaten human health. In order to investigate the impact...The photo-reactions between metabolic products of human sweat and dyestuffs on garments may produce many toxic substances which could directly contact skin and threaten human health. In order to investigate the impact of the perspiration on photo-fading of reactive dyes on cellulose, nine commercial reactive dyes belonging to three types of chromophores (azo, Cu-complex azo and anthraquinone) respectively were chosen and their perspiration-light stability on cotton fabric was studied following ATTS test standard. It is found that the impact of the artificial perspiration on dyes varies with different chromophores: anthraquinone reactive dyes always show the best photo-stability, whereas Cu-complex azo reactive dyes appear to be the most sensitive under exposure to light and perspiration. The pH value of perspiration also greatly influences the fading of dyes with different reactive groups: the fading rate of most chlorotriazinyl reactive dyes in acidic perspiration (pH=3.5) is higher than in alkaline perspiration (pH=8.0), while the reverse is true for most vinylsulphonyl dyes. Furthermore, the study of the contribution of individual component of the artificial perspiration discloses that L-Histidine monohydrochloride monohydrate, DL-Aspartic acid and lactic acid play the major roles on the photo-fading of those selected dyestuffs and inorganic salts including disodium hydrogen phosphate and sodium chloride usually decelerate photo-fading.展开更多
Explosive reactive armor(ERA)is currently being actively developed as a protective system for mobile devices against ballistic threats such as kinetic energy penetrators and shaped-charge jets.Considering mobility,the...Explosive reactive armor(ERA)is currently being actively developed as a protective system for mobile devices against ballistic threats such as kinetic energy penetrators and shaped-charge jets.Considering mobility,the aim is to design a protection system with a minimal amount of required mass.The efficiency of an ERA is sensitive to the impact position and the timing of the detonation.Therefore,different designs have to be tested for several impact scenarios to identify the best design.Since analytical models are not predicting the behavior of the ERA accurately enough and experiments,as well as numerical simulations,are too time-consuming,a data-driven model to estimate the displacements and deformation of plates of an ERA system is proposed here.The ground truth for the artificial neural network(ANN)is numerical simulation results that are validated with experiments.The ANN approximates the plate positions for different materials,plate sizes,and detonation point positions with sufficient accuracy in real-time.In a future investigation,the results from the model can be used to estimate the interaction of the ERA with a given threat.Then,a measure for the effectiveness of an ERA can be calculated.Finally,an optimal ERA can be designed and analyzed for any possible impact scenario in negligible time.展开更多
文摘This paper presents the rigorous study of mobile robot navigation techniques used so far.The step by step investigations of classical and reactive approaches are made here to understand the development of path planning strategies in various environmental conditions and to identify research gap.The classical approaches such as cell decomposition(CD),roadmap approach(RA),artificial potential field(APF);reactive approaches such as genetic algorithm(GA),fuzzy logic(FL),neural network(NN),firefly algorithm(FA),particle swarm optimization(PSO),ant colony optimization(ACO),bacterial foraging optimization(BFO),artificial bee colony(ABC),cuckoo search(CS),shuffled frog leaping algorithm(SFLA)and other miscellaneous algorithms(OMA)are considered for study.The navigation over static and dynamic condition is analyzed(for single and multiple robot systems)and it has been observed that the reactive approaches are more robust and perform well in all terrain when compared to classical approaches.It is also observed that the reactive approaches are used to improve the performance of the classical approaches as a hybrid algorithm.Hence,reactive approaches are more popular and widely used for path planning of mobile robot.The paper concludes with tabular data and charts comparing the frequency of individual navigational strategies which can be used for specific application in robotics.
基金Supported by Foundation of University Doctoral Programby the State Ministry of Education (No.20050255002)
文摘The photo-reactions between metabolic products of human sweat and dyestuffs on garments may produce many toxic substances which could directly contact skin and threaten human health. In order to investigate the impact of the perspiration on photo-fading of reactive dyes on cellulose, nine commercial reactive dyes belonging to three types of chromophores (azo, Cu-complex azo and anthraquinone) respectively were chosen and their perspiration-light stability on cotton fabric was studied following ATTS test standard. It is found that the impact of the artificial perspiration on dyes varies with different chromophores: anthraquinone reactive dyes always show the best photo-stability, whereas Cu-complex azo reactive dyes appear to be the most sensitive under exposure to light and perspiration. The pH value of perspiration also greatly influences the fading of dyes with different reactive groups: the fading rate of most chlorotriazinyl reactive dyes in acidic perspiration (pH=3.5) is higher than in alkaline perspiration (pH=8.0), while the reverse is true for most vinylsulphonyl dyes. Furthermore, the study of the contribution of individual component of the artificial perspiration discloses that L-Histidine monohydrochloride monohydrate, DL-Aspartic acid and lactic acid play the major roles on the photo-fading of those selected dyestuffs and inorganic salts including disodium hydrogen phosphate and sodium chloride usually decelerate photo-fading.
文摘Explosive reactive armor(ERA)is currently being actively developed as a protective system for mobile devices against ballistic threats such as kinetic energy penetrators and shaped-charge jets.Considering mobility,the aim is to design a protection system with a minimal amount of required mass.The efficiency of an ERA is sensitive to the impact position and the timing of the detonation.Therefore,different designs have to be tested for several impact scenarios to identify the best design.Since analytical models are not predicting the behavior of the ERA accurately enough and experiments,as well as numerical simulations,are too time-consuming,a data-driven model to estimate the displacements and deformation of plates of an ERA system is proposed here.The ground truth for the artificial neural network(ANN)is numerical simulation results that are validated with experiments.The ANN approximates the plate positions for different materials,plate sizes,and detonation point positions with sufficient accuracy in real-time.In a future investigation,the results from the model can be used to estimate the interaction of the ERA with a given threat.Then,a measure for the effectiveness of an ERA can be calculated.Finally,an optimal ERA can be designed and analyzed for any possible impact scenario in negligible time.
