The paper is devoted to the elastostatic calibration of industrial robots,which is used for precise machining of large-dimensional parts made of composite materials.In this technological process,the interaction betwee...The paper is devoted to the elastostatic calibration of industrial robots,which is used for precise machining of large-dimensional parts made of composite materials.In this technological process,the interaction between the robot and the workpiece causes essential elastic deflections of the manipulator components that should be compensated by the robot controller using relevant elastostatic model of this mechanism.To estimate parameters of this model,an advanced calibration technique is applied that is based on the non-linear experiment design theory,which is adopted for this particular application.In contrast to previous works,it is proposed a concept of the user-defined test-pose,which is used to evaluate the calibration experiments quality.In the frame of this concept,the related optimization problem is defined and numerical routines are developed,which allow generating optimal set of manipulator configurations and corresponding forces/torques for a given number of the calibration experiments.Some specific kinematic constraints are also taken into account,which insure feasibility of calibration experiments for the obtained configurations and allow avoiding collision between the robotic manipulator and the measurement equipment.The efficiency of the developed technique is illustrated by an application example that deals with elastostatic calibration of the serial manipulator used for robot-based machining.展开更多
This paper records the author's comments and reflection on reading Siegel's(2013) article on L2 listening instruction.It first summarizes major arguments put forward in Siegel's(2013) article, and then pro...This paper records the author's comments and reflection on reading Siegel's(2013) article on L2 listening instruction.It first summarizes major arguments put forward in Siegel's(2013) article, and then proceeds to review commonly used approaches to L2 listening instruction, after which it examines the discrepancy between research and practice. In the end, the author gives some suggestions for further research.展开更多
文摘The paper is devoted to the elastostatic calibration of industrial robots,which is used for precise machining of large-dimensional parts made of composite materials.In this technological process,the interaction between the robot and the workpiece causes essential elastic deflections of the manipulator components that should be compensated by the robot controller using relevant elastostatic model of this mechanism.To estimate parameters of this model,an advanced calibration technique is applied that is based on the non-linear experiment design theory,which is adopted for this particular application.In contrast to previous works,it is proposed a concept of the user-defined test-pose,which is used to evaluate the calibration experiments quality.In the frame of this concept,the related optimization problem is defined and numerical routines are developed,which allow generating optimal set of manipulator configurations and corresponding forces/torques for a given number of the calibration experiments.Some specific kinematic constraints are also taken into account,which insure feasibility of calibration experiments for the obtained configurations and allow avoiding collision between the robotic manipulator and the measurement equipment.The efficiency of the developed technique is illustrated by an application example that deals with elastostatic calibration of the serial manipulator used for robot-based machining.
文摘This paper records the author's comments and reflection on reading Siegel's(2013) article on L2 listening instruction.It first summarizes major arguments put forward in Siegel's(2013) article, and then proceeds to review commonly used approaches to L2 listening instruction, after which it examines the discrepancy between research and practice. In the end, the author gives some suggestions for further research.
