Approximation methods are used in the analysis and prediction of data, especially laboratory data, in engineering projects. These methods are usually linear and are obtained by least-square-error approaches. There are...Approximation methods are used in the analysis and prediction of data, especially laboratory data, in engineering projects. These methods are usually linear and are obtained by least-square-error approaches. There are many problems in which linear models cannot be applied. Because of that there are logarithmic, exponential and polynomial curve-fitting models. These nonlinear models have a limited application in engineering problems. The variation of most data is such that the nonlinearity cannot be approximated by the above approaches. These methods are also not applicable when there is a large amount of data. For these reasons, a method of piecewise cubic spline approximation has been developed. The model presented here is capable of following the local nonuniformity of data in order to obtain a good fit of a curve to the data. There is C1 continuity at the limits of the piecewise elements. The model is tested and examined with four problems here. The results show that the model can approximate highly nonlinear data efficiently.展开更多
针对传统人工操控塔式起重机在运输货物时易导致路径拐点多、负载摆动大的问题,提出一种改进的人工鱼群塔式起重机智能路径规划的新算法。根据塔式起重机的工作环境,建立三维的地图环境模型来模拟障碍物较多的复杂建筑环境,并结合起重...针对传统人工操控塔式起重机在运输货物时易导致路径拐点多、负载摆动大的问题,提出一种改进的人工鱼群塔式起重机智能路径规划的新算法。根据塔式起重机的工作环境,建立三维的地图环境模型来模拟障碍物较多的复杂建筑环境,并结合起重机在建筑场所的运行特点,对传统人工鱼群算法(artificial fish swarm algorithm, AFSA)进行改进,采用自适应策略让鱼群在寻优过程中的状态不断变化,及时调整自身的移动步长和视野,并基于生存竞争机制对人工鱼的随机行为进行改进,在一定程度上改善了算法的寻优能力,利用三次方样条数据插值拟合曲线得到更适合塔式起重机的光滑避障路径。仿真结果表明,改进后的算法为塔式起重机在障碍物较多的复杂建筑环境下找到一条最优避障路径。展开更多
文摘Approximation methods are used in the analysis and prediction of data, especially laboratory data, in engineering projects. These methods are usually linear and are obtained by least-square-error approaches. There are many problems in which linear models cannot be applied. Because of that there are logarithmic, exponential and polynomial curve-fitting models. These nonlinear models have a limited application in engineering problems. The variation of most data is such that the nonlinearity cannot be approximated by the above approaches. These methods are also not applicable when there is a large amount of data. For these reasons, a method of piecewise cubic spline approximation has been developed. The model presented here is capable of following the local nonuniformity of data in order to obtain a good fit of a curve to the data. There is C1 continuity at the limits of the piecewise elements. The model is tested and examined with four problems here. The results show that the model can approximate highly nonlinear data efficiently.
文摘针对传统人工操控塔式起重机在运输货物时易导致路径拐点多、负载摆动大的问题,提出一种改进的人工鱼群塔式起重机智能路径规划的新算法。根据塔式起重机的工作环境,建立三维的地图环境模型来模拟障碍物较多的复杂建筑环境,并结合起重机在建筑场所的运行特点,对传统人工鱼群算法(artificial fish swarm algorithm, AFSA)进行改进,采用自适应策略让鱼群在寻优过程中的状态不断变化,及时调整自身的移动步长和视野,并基于生存竞争机制对人工鱼的随机行为进行改进,在一定程度上改善了算法的寻优能力,利用三次方样条数据插值拟合曲线得到更适合塔式起重机的光滑避障路径。仿真结果表明,改进后的算法为塔式起重机在障碍物较多的复杂建筑环境下找到一条最优避障路径。
