Motion accuracy of space manipulators has direct effects on the ability of the systems to perform specified tasks. However, some design variables are inherently interval parameters due to uncertainties in geometric st...Motion accuracy of space manipulators has direct effects on the ability of the systems to perform specified tasks. However, some design variables are inherently interval parameters due to uncertainties in geometric structures, material properties, and so on. This paper presents Chebyshev inclusion function(CIF) for approximating the dynamic responses function of parametrically excited systems. Motion accuracy reliability(MAR) of space manipulators was evaluated based on mechanism reliability analysis methods and interval uncertainty model. To illustrate the accuracy of the proposed method, a two-link manipulator with interval parameters was demonstrated. The results showed that the proposed method required much fewer samples to obtain more accurate reliability compared with the traditional Monte Carlo simulation(MCS). Finally, the sensitivity analysis was performed to facilitate the optimization design by using global sensitivity analysis.展开更多
The fuzzy comfortability of a wind-sensitive super-high tower crane is critical to guarantee occupant health and improve construction efficiency.Therefore,the wind-resistant fuzzy comfortability of a super-high tower ...The fuzzy comfortability of a wind-sensitive super-high tower crane is critical to guarantee occupant health and improve construction efficiency.Therefore,the wind-resistant fuzzy comfortability of a super-high tower crane in the Ma’anshan Yangtze River(MYR)Bridge site is analyzed in this paper.First,the membership function model that represents fuzzy comfortability is introduced in the probability density evolution method(PDEM).Second,based on Fechner’s law,the membership function curves are constructed according to three acceleration thresholds in ISO 2631.Then,the fuzzy comfortability for the super-high tower crane under stochastic wind loads is assessed on the basis of different cut-set levelsλ.Results show that the comfortability is over 0.9 under the required maximum operating wind velocity.The low sensitivity toλcan be observed in the reliability curves of ISOⅡandⅢmembership functions.The reliability of the ISOⅠmembership function is not sensitive toλwhenλ<0.7,whereas it becomes sensitive toλwhenλ>0.7.展开更多
以配电网可靠性最高为目标函数和配电网的运行满足电力连续供戍为约束条件,提出了基于排序选择、对违反约束个体进行直接比较的改进自适应遗传算法。这是一种对配电网的可靠性按照深度优先搜索最小路径进行计算的方法。通过IEEE典型算例...以配电网可靠性最高为目标函数和配电网的运行满足电力连续供戍为约束条件,提出了基于排序选择、对违反约束个体进行直接比较的改进自适应遗传算法。这是一种对配电网的可靠性按照深度优先搜索最小路径进行计算的方法。通过IEEE典型算例RBTS Bus 4系统的验证,表明该算法是有效的。与禁忌搜索算法(TS)比较,该算法可获得最优方案,而禁忌搜索算法只能获得次优方案。展开更多
基金Sponsored by the National Natural Science Foundation of China(Grant No.51675026)
文摘Motion accuracy of space manipulators has direct effects on the ability of the systems to perform specified tasks. However, some design variables are inherently interval parameters due to uncertainties in geometric structures, material properties, and so on. This paper presents Chebyshev inclusion function(CIF) for approximating the dynamic responses function of parametrically excited systems. Motion accuracy reliability(MAR) of space manipulators was evaluated based on mechanism reliability analysis methods and interval uncertainty model. To illustrate the accuracy of the proposed method, a two-link manipulator with interval parameters was demonstrated. The results showed that the proposed method required much fewer samples to obtain more accurate reliability compared with the traditional Monte Carlo simulation(MCS). Finally, the sensitivity analysis was performed to facilitate the optimization design by using global sensitivity analysis.
基金The National Natural Science Foundation of China(No.52108274,52208481,52338011)State Scholarship Fund of China Scholarship Council(No.202306090285).
文摘The fuzzy comfortability of a wind-sensitive super-high tower crane is critical to guarantee occupant health and improve construction efficiency.Therefore,the wind-resistant fuzzy comfortability of a super-high tower crane in the Ma’anshan Yangtze River(MYR)Bridge site is analyzed in this paper.First,the membership function model that represents fuzzy comfortability is introduced in the probability density evolution method(PDEM).Second,based on Fechner’s law,the membership function curves are constructed according to three acceleration thresholds in ISO 2631.Then,the fuzzy comfortability for the super-high tower crane under stochastic wind loads is assessed on the basis of different cut-set levelsλ.Results show that the comfortability is over 0.9 under the required maximum operating wind velocity.The low sensitivity toλcan be observed in the reliability curves of ISOⅡandⅢmembership functions.The reliability of the ISOⅠmembership function is not sensitive toλwhenλ<0.7,whereas it becomes sensitive toλwhenλ>0.7.
文摘以配电网可靠性最高为目标函数和配电网的运行满足电力连续供戍为约束条件,提出了基于排序选择、对违反约束个体进行直接比较的改进自适应遗传算法。这是一种对配电网的可靠性按照深度优先搜索最小路径进行计算的方法。通过IEEE典型算例RBTS Bus 4系统的验证,表明该算法是有效的。与禁忌搜索算法(TS)比较,该算法可获得最优方案,而禁忌搜索算法只能获得次优方案。
