： This paper deals with the universal serial manipulator on the inverse kinematics problem of plane type, the fast working space solution method, and the obstacle avoidance path planning method. With the vector proje...： This paper deals with the universal serial manipulator on the inverse kinematics problem of plane type, the fast working space solution method, and the obstacle avoidance path planning method. With the vector projection as the main constraint condition of the target, it proposes a general form of the inverse kinematics solution which does not depend on the robot configuration of freedom degree. By identifying the target vector direction maximum and minimum workspace boundary and determining the destination vector by thick search on the workspaee boundary method, an expressing method of the polar coordinate form of work space is then introduced. Finally, according to the form of plane trajectory planning for obstacle avoidance problem, the method of solving the inverse kinematics solution of the concave and convex forms of the safe obstacle avoidance area is improved. The simulation results verify that the proposed method has feasibility and generality.展开更多
The space target imaging is important in the development of space technology.Due to the availability of trajectory information of the space targets and the arising of rapid parallel processing hardware,the back projec...The space target imaging is important in the development of space technology.Due to the availability of trajectory information of the space targets and the arising of rapid parallel processing hardware,the back projection (BP) method has been applied to synthetic aperture radar (SAR) imaging and shows a number of advantages as compared with conventional Fourier-domain imaging algorithms.However,the practical processing shows that the insufficient accuracy of the trajectory information results in the degrading of the imaging results.On the other hand,the autofocusing algorithms for BP imaging are not well developed,which is a bottleneck for the application of BP imaging.Here,an analysis of the effect of trajectory errors on the space target imaging using microlocal technology is presented.Our analysis provides an explicit quantitative relationship between the trajectory errors of the space target and the positioning errors in the reconstructed images.The explicit form of the position errors for some typical trajectory errors is also presented.Numerical simulations demonstrate our theoretical findings.The measured position errors obtained from the reconstructed images are consistent with the analytic errors calculated by using the derived formulas.Our results will be used in the development of effective autofocusing methods for BP imaging.展开更多
对自由曲面的数控加工,寻求最优的刀具轨迹生成方法至关重要。本文基于开源3D库Open CASCADE(OCC)和编程开发环境Microsoft Visual Studio 2010(VS2010),应用B样条表达的自由曲面,采用“投影法”思想,研究“重用已有相似刀具路径”方法...对自由曲面的数控加工,寻求最优的刀具轨迹生成方法至关重要。本文基于开源3D库Open CASCADE(OCC)和编程开发环境Microsoft Visual Studio 2010(VS2010),应用B样条表达的自由曲面,采用“投影法”思想,研究“重用已有相似刀具路径”方法,提出了处理自由曲面的NC刀具轨迹映射算法。为了验证算法的有效性和可行性,实验建立5类自由曲面,启动设计的轨迹映射算法,输出曲面的NC加工轨迹质量可以满足设计要求,实现了刀具轨迹的重用。展开更多
基金Sponsored by the National Natural Science Foundation of China(Grant No.51205074)the Specialized Research Fund for the Doctoral Program of Higher Education(Grant No.20112304120007)+2 种基金the Harbin Specialized Research Foundation for Innovation Talents(Grant No.RC2012QN009037)the Fundamental Research Funds for the Central Universities(Grant No.HEUCF041505)the State Commission of Science Technology of China(Grant No.2014DFR10010)
文摘： This paper deals with the universal serial manipulator on the inverse kinematics problem of plane type, the fast working space solution method, and the obstacle avoidance path planning method. With the vector projection as the main constraint condition of the target, it proposes a general form of the inverse kinematics solution which does not depend on the robot configuration of freedom degree. By identifying the target vector direction maximum and minimum workspace boundary and determining the destination vector by thick search on the workspaee boundary method, an expressing method of the polar coordinate form of work space is then introduced. Finally, according to the form of plane trajectory planning for obstacle avoidance problem, the method of solving the inverse kinematics solution of the concave and convex forms of the safe obstacle avoidance area is improved. The simulation results verify that the proposed method has feasibility and generality.
基金supported by the National Natural Science Foundation of China(No.61871217)the Foundation of Graduate Innovation Center in Nanjing University of Aeronautics and Astronautics(No.kfjj20170404),China
文摘The space target imaging is important in the development of space technology.Due to the availability of trajectory information of the space targets and the arising of rapid parallel processing hardware,the back projection (BP) method has been applied to synthetic aperture radar (SAR) imaging and shows a number of advantages as compared with conventional Fourier-domain imaging algorithms.However,the practical processing shows that the insufficient accuracy of the trajectory information results in the degrading of the imaging results.On the other hand,the autofocusing algorithms for BP imaging are not well developed,which is a bottleneck for the application of BP imaging.Here,an analysis of the effect of trajectory errors on the space target imaging using microlocal technology is presented.Our analysis provides an explicit quantitative relationship between the trajectory errors of the space target and the positioning errors in the reconstructed images.The explicit form of the position errors for some typical trajectory errors is also presented.Numerical simulations demonstrate our theoretical findings.The measured position errors obtained from the reconstructed images are consistent with the analytic errors calculated by using the derived formulas.Our results will be used in the development of effective autofocusing methods for BP imaging.
文摘对自由曲面的数控加工,寻求最优的刀具轨迹生成方法至关重要。本文基于开源3D库Open CASCADE(OCC)和编程开发环境Microsoft Visual Studio 2010(VS2010),应用B样条表达的自由曲面,采用“投影法”思想,研究“重用已有相似刀具路径”方法,提出了处理自由曲面的NC刀具轨迹映射算法。为了验证算法的有效性和可行性,实验建立5类自由曲面,启动设计的轨迹映射算法,输出曲面的NC加工轨迹质量可以满足设计要求,实现了刀具轨迹的重用。
