以3个不同林龄的桉树品系16株样木为材料,以2种区分段所得干曲线方程,构建立木三维立体结构并对其单株材积测算方法,就所获得5种单株材积以及其形数进行了计算比较。结果表明:来自不同2种区分段所建立的干曲线方程模型拟合效果好,最大...以3个不同林龄的桉树品系16株样木为材料,以2种区分段所得干曲线方程,构建立木三维立体结构并对其单株材积测算方法,就所获得5种单株材积以及其形数进行了计算比较。结果表明:来自不同2种区分段所建立的干曲线方程模型拟合效果好,最大多数的模型决定系数R2大于0.99,SEE(Standard Error of the Estimate)较小,能很好对样木的树干干形进行解析;但不同的区分段差别较大,其中1 m区分段所获得树干曲线方程拟合效果(R2>0.98)优于1.3 m区分段;5种单株计算方法所得材积(2种区分段求积法、2种三维立体结构求积法与常规桉树二元材积法)之间没有显著差异,但存在着极显著的线性相关性;对4个林分的形数分析表明,不同林分立木在胸高形数差异显著,表现出胸高形数随着林分林龄增大而逐步减小的趋势。在胸高形数上5种单株材积测算存在着差异显著。1 m区分段下所得三维立体所得材积V4以及胸高形数均与其相应的区分求积法所得材积V2和胸高形数接近,因此可利用1m区分段建立干曲线方程获得树干三维立体结构,测算接近真实的单株材积。展开更多
A new motion planning method is proposed for enlarging the solvable space of zero-disturbance motion planning for the space free-floating manipulator system. First, a class of translational zero-disturbance curves is ...A new motion planning method is proposed for enlarging the solvable space of zero-disturbance motion planning for the space free-floating manipulator system. First, a class of translational zero-disturbance curves is put forward for the first time. The equation of translational zero-disturbance curve is deduced using the nonholonomic constraint of the manipulator system, and its characteristics are also discussed. Second, the zero-disturbance curve of the whole operating process is divided into two segments. The first one is a translational zero-disturbance curve which passes through the target point. Another one is a common zero-disturbance curve which passes through the original point and intersects with the translational zero-disturbance curve. Finally, the common zero-disturbance curve is obtained by a hybrid programming strategy based on Gauss pseudo-spectral method (GPM) and direct shooting method (DSM). The numerical simulation results indicate that the proposed method is effective, and that the solvable space of this method almost covers the whole work space of the manipulator system.展开更多
文摘以3个不同林龄的桉树品系16株样木为材料,以2种区分段所得干曲线方程,构建立木三维立体结构并对其单株材积测算方法,就所获得5种单株材积以及其形数进行了计算比较。结果表明:来自不同2种区分段所建立的干曲线方程模型拟合效果好,最大多数的模型决定系数R2大于0.99,SEE(Standard Error of the Estimate)较小,能很好对样木的树干干形进行解析;但不同的区分段差别较大,其中1 m区分段所获得树干曲线方程拟合效果(R2>0.98)优于1.3 m区分段;5种单株计算方法所得材积(2种区分段求积法、2种三维立体结构求积法与常规桉树二元材积法)之间没有显著差异,但存在着极显著的线性相关性;对4个林分的形数分析表明,不同林分立木在胸高形数差异显著,表现出胸高形数随着林分林龄增大而逐步减小的趋势。在胸高形数上5种单株材积测算存在着差异显著。1 m区分段下所得三维立体所得材积V4以及胸高形数均与其相应的区分求积法所得材积V2和胸高形数接近,因此可利用1m区分段建立干曲线方程获得树干三维立体结构,测算接近真实的单株材积。
文摘A new motion planning method is proposed for enlarging the solvable space of zero-disturbance motion planning for the space free-floating manipulator system. First, a class of translational zero-disturbance curves is put forward for the first time. The equation of translational zero-disturbance curve is deduced using the nonholonomic constraint of the manipulator system, and its characteristics are also discussed. Second, the zero-disturbance curve of the whole operating process is divided into two segments. The first one is a translational zero-disturbance curve which passes through the target point. Another one is a common zero-disturbance curve which passes through the original point and intersects with the translational zero-disturbance curve. Finally, the common zero-disturbance curve is obtained by a hybrid programming strategy based on Gauss pseudo-spectral method (GPM) and direct shooting method (DSM). The numerical simulation results indicate that the proposed method is effective, and that the solvable space of this method almost covers the whole work space of the manipulator system.
