In this paper,we present a robot vision based system for coordinate measurement of feature points on large scale automobile parts.Our system consists of an industrial 6-DOF robot mounted with a CCD camera and a PC.The...In this paper,we present a robot vision based system for coordinate measurement of feature points on large scale automobile parts.Our system consists of an industrial 6-DOF robot mounted with a CCD camera and a PC.The system controls the robot into the area of feature points.The images of measuring feature points are acquired by the camera mounted on the robot.3D positions of the feature points are obtained from a model based pose estimation that applies to the images.The measured positions of all feature points are then transformed to the reference coordinate of feature points whose positions are obtained from the coordinate measuring machine（CMM）.Finally,the point-to-point distances between the measured feature points and the reference feature points are calculated and reported.The results show that the root mean square error（RMSE） of measure values obtained by our system is less than 0.5 mm.Our system is adequate for automobile assembly and can perform faster than conventional methods.展开更多
According to the theory that rotation transformation from the basecoordinate to an arbitrary one can be described by a single equivalent rotation about agiven rotational axis,it is proposed that the orientation of rob...According to the theory that rotation transformation from the basecoordinate to an arbitrary one can be described by a single equivalent rotation about agiven rotational axis,it is proposed that the orientation of robot can be described by usingthe vector of equivalent angular displacement.And the concept of pose motor and itsPlücker linear coordinate are established and used to describe the position and orientationof robot.Based on the fact that there is a one-to-one correspondence between the ori-ented straight lines in three-dimensional dual space,the interpolation plannings corre-sponding to the pose motors are developed in dual space.A new algorithm of robot CPmotion trajectory planning is presented.The correctness of the theory and derivation isconformed by an example.展开更多
In order to improve the travelling ability of the wheel-type pipeline robot in elbow section of pipeline, the model of drive ratios is proposed aiming at the pipeline robots with different configurations. Through the ...In order to improve the travelling ability of the wheel-type pipeline robot in elbow section of pipeline, the model of drive ratios is proposed aiming at the pipeline robots with different configurations. Through the movement analysis of the robot with different configurations in elbow section, the pose model of the robot is established, and the coordinates of the wheel centers and the contact points can be got through the calculation of the pose model. Based on the pose model established, the corresponding drive ratios are obtained combining with the relations of the velocities of wheel centers and rotative velocities of wheels under the movement condition with no interference. The virtual simulations and prototype experiments are carried out, and the drive ratios accuracy of the model when the robot moved in elbow without interference is validated.展开更多
A 6-DOF micro-manipulation robot based on a 3-PPTTRS mechanism is proposed in this paper.Its static stiffness is an important index to evaluate load capacity and positioning accuracy.However,it is insufficient to cons...A 6-DOF micro-manipulation robot based on a 3-PPTTRS mechanism is proposed in this paper.Its static stiffness is an important index to evaluate load capacity and positioning accuracy.However,it is insufficient to consider the static stiffness only when the robot is in its initial pose.The stiffness in different positions and poses in its work space must be analyzed also.Thus a method to analyze the relationship between static stiffness and poses in the whole work space is presented.A static stiffness model is proposed first,and the relationship between structural parameters and static stiffness in different poses is discussed.The static stiffness analysis provides foundation for structural parameter design.展开更多
经颅磁刺激(transcranial magnetic stimulation, TMS)是一种神经调制方法,临床中凭借医生经验手动确定TMS线圈摆放位姿,导致线圈摆放位置和姿态不准确且重复定位精度差。针对上述问题,提出一种TMS线圈机器人辅助定位系统,使用RGB相机...经颅磁刺激(transcranial magnetic stimulation, TMS)是一种神经调制方法,临床中凭借医生经验手动确定TMS线圈摆放位姿,导致线圈摆放位置和姿态不准确且重复定位精度差。针对上述问题,提出一种TMS线圈机器人辅助定位系统,使用RGB相机替代导航系统中双目红外相机,采用一种基于神经网络的无标志物TMS线圈机器人辅助定位方法。搭建神经网络实现相机空间线圈姿态到操作臂空间关节角度的映射,并通过仿真数据训练验证了该神经网络架构适用于TMS线圈位姿摆放问题。随后,通过实验验证了该方法的可行性,同时表明训练的神经网络针对TMS线圈定位任务具有良好的泛化能力。最后,在笛卡儿空间的位姿验证结果显示TMS线圈三维位置平均误差为2.16 mm,总体姿态误差为0.055 rad,使用RGB相机的TMS线圈机器人辅助定位系统在精度上达到了与其他使用双目红外相机的科研或商用系统相同的水平,满足TMS临床治疗要求,具备临床应用的可行性。展开更多
基金wsupported by the Thailand Research Fund and Solimac Automation Co.,Ltd.under the Research and Researchers for Industry Program(RRI)under Grant No.MSD56I0098Office of the Higher Education Commission under the National Research University Project of Thailand
文摘In this paper,we present a robot vision based system for coordinate measurement of feature points on large scale automobile parts.Our system consists of an industrial 6-DOF robot mounted with a CCD camera and a PC.The system controls the robot into the area of feature points.The images of measuring feature points are acquired by the camera mounted on the robot.3D positions of the feature points are obtained from a model based pose estimation that applies to the images.The measured positions of all feature points are then transformed to the reference coordinate of feature points whose positions are obtained from the coordinate measuring machine（CMM）.Finally,the point-to-point distances between the measured feature points and the reference feature points are calculated and reported.The results show that the root mean square error（RMSE） of measure values obtained by our system is less than 0.5 mm.Our system is adequate for automobile assembly and can perform faster than conventional methods.
文摘According to the theory that rotation transformation from the basecoordinate to an arbitrary one can be described by a single equivalent rotation about agiven rotational axis,it is proposed that the orientation of robot can be described by usingthe vector of equivalent angular displacement.And the concept of pose motor and itsPlücker linear coordinate are established and used to describe the position and orientationof robot.Based on the fact that there is a one-to-one correspondence between the ori-ented straight lines in three-dimensional dual space,the interpolation plannings corre-sponding to the pose motors are developed in dual space.A new algorithm of robot CPmotion trajectory planning is presented.The correctness of the theory and derivation isconformed by an example.
基金Supported by the High-Tech Research and Development Program of China (2006AA04Z236)the"111"Project(B07018)the Self-Planned Task of State Key Laboratory of Robotics and System (HIT) (SKLRS200802C)
文摘In order to improve the travelling ability of the wheel-type pipeline robot in elbow section of pipeline, the model of drive ratios is proposed aiming at the pipeline robots with different configurations. Through the movement analysis of the robot with different configurations in elbow section, the pose model of the robot is established, and the coordinates of the wheel centers and the contact points can be got through the calculation of the pose model. Based on the pose model established, the corresponding drive ratios are obtained combining with the relations of the velocities of wheel centers and rotative velocities of wheels under the movement condition with no interference. The virtual simulations and prototype experiments are carried out, and the drive ratios accuracy of the model when the robot moved in elbow without interference is validated.
文摘A 6-DOF micro-manipulation robot based on a 3-PPTTRS mechanism is proposed in this paper.Its static stiffness is an important index to evaluate load capacity and positioning accuracy.However,it is insufficient to consider the static stiffness only when the robot is in its initial pose.The stiffness in different positions and poses in its work space must be analyzed also.Thus a method to analyze the relationship between static stiffness and poses in the whole work space is presented.A static stiffness model is proposed first,and the relationship between structural parameters and static stiffness in different poses is discussed.The static stiffness analysis provides foundation for structural parameter design.
