An optimal measurement pose number searching method was designed to improve the pose selection method.Several optimal robot measurement configurations were added to an initial pre-selected optimal configuration set to...An optimal measurement pose number searching method was designed to improve the pose selection method.Several optimal robot measurement configurations were added to an initial pre-selected optimal configuration set to establish a new configuration set for robot calibration one by one.The root mean squares (RMS) of the errors of each end-effector poses after being calibrated by these configuration sets were calculated.The optimal number of the configuration set corresponding to the least RMS of pose error was then obtained.Calibration based on those poses selected by this algorithm can get higher end-effector accuracy,meanwhile consumes less time.An optimal pose set including optimal 25 measurement configurations is found during the simulation.Tracking errors after calibration by using these poses are 1.54,1.61 and 0.86 mm,and better than those before calibration which are 7.79,7.62 and 8.29 mm,even better than those calibrated by the random method which are 2.22,2.35 and 1.69 mm in directions X,Y and Z,respectively.展开更多
Due to the intense vibration durirLg launching and rigorous orbital temperature environment, the kinematic parameters of space robot may be largely deviated from their nominal parameters. The disparity will cause the ...Due to the intense vibration durirLg launching and rigorous orbital temperature environment, the kinematic parameters of space robot may be largely deviated from their nominal parameters. The disparity will cause the real pose （including position and orientation） of the end effector not to match the desired one, and further hinder the space robot from performing the scheduled mission. To improve pose accuracy of space robot, a new self-calibration method using the distance measurement provided by a laser-ranger fixed on the end-effector is proposed. A distance-measurement model of the space robot is built according to the distance from the starting point of the laser beam to the intersection point at the declining plane. Based on the model, the cost function about the pose error is derived. The kinematic calibration is transferred to a non-linear system optimization problem, which is solved by the improved differential evolution （DE） algoritlun. A six-degree of freedom （6-DOF） robot is used as a practical simulation example, and the simulation results show： 1） A significant improvement of pose accuracy of space robot can be obtained by distance measurement only; 2） Search efficiency is increased by improved DE; 3） More calibration configurations may make calibration results better.展开更多
基金Project(2008AA04Z203) supported by the National High Technology Research and Development Program of China
文摘An optimal measurement pose number searching method was designed to improve the pose selection method.Several optimal robot measurement configurations were added to an initial pre-selected optimal configuration set to establish a new configuration set for robot calibration one by one.The root mean squares (RMS) of the errors of each end-effector poses after being calibrated by these configuration sets were calculated.The optimal number of the configuration set corresponding to the least RMS of pose error was then obtained.Calibration based on those poses selected by this algorithm can get higher end-effector accuracy,meanwhile consumes less time.An optimal pose set including optimal 25 measurement configurations is found during the simulation.Tracking errors after calibration by using these poses are 1.54,1.61 and 0.86 mm,and better than those before calibration which are 7.79,7.62 and 8.29 mm,even better than those calibrated by the random method which are 2.22,2.35 and 1.69 mm in directions X,Y and Z,respectively.
基金Projects(60775049,60805033) supported by National Natural Science Foundation of ChinaProject(2007AA704317) supported by the National High Technology Research and Development Program of China
文摘Due to the intense vibration durirLg launching and rigorous orbital temperature environment, the kinematic parameters of space robot may be largely deviated from their nominal parameters. The disparity will cause the real pose （including position and orientation） of the end effector not to match the desired one, and further hinder the space robot from performing the scheduled mission. To improve pose accuracy of space robot, a new self-calibration method using the distance measurement provided by a laser-ranger fixed on the end-effector is proposed. A distance-measurement model of the space robot is built according to the distance from the starting point of the laser beam to the intersection point at the declining plane. Based on the model, the cost function about the pose error is derived. The kinematic calibration is transferred to a non-linear system optimization problem, which is solved by the improved differential evolution （DE） algoritlun. A six-degree of freedom （6-DOF） robot is used as a practical simulation example, and the simulation results show： 1） A significant improvement of pose accuracy of space robot can be obtained by distance measurement only; 2） Search efficiency is increased by improved DE; 3） More calibration configurations may make calibration results better.
