A new kind of eight-wheel lunar rover is developed, which is a complex closed-chain system and has good capabilities of climbing slope, surmounting obstacles and adapting to uneven terrain. In this paper, the mechanic...A new kind of eight-wheel lunar rover is developed, which is a complex closed-chain system and has good capabilities of climbing slope, surmounting obstacles and adapting to uneven terrain. In this paper, the mechanical structure of the novel eight-wheel lunar rover is introduced, forward and inverse kinematic models of the rover are established according to the closed-chain coordinate transformation and instantaneous coincidence coordinate. Based on structural characteristics, its kinetic characteristics are analyzed. Wheel slippages are separated and calculated, and a method for closed-loop control modification using wheel slip estimation during the model establishment is proposed. The results can be applied to the motion control of lunar rover.展开更多
In this study, we aim at obtaining inverse kinematic model of a serial manipulator using spatial operator algebra. For testing the inverse kinematic algorithm, the Vpython software program which has simultaneous view ...In this study, we aim at obtaining inverse kinematic model of a serial manipulator using spatial operator algebra. For testing the inverse kinematic algorithm, the Vpython software program which has simultaneous view and software working, is used. The aim is to measure the inverse kinematics modeling work on different serial manipulator mechanisms with spatial vector algebra. The algorithm is used with the same reference inputs on the recursive, exact and nonrecursive manipulators. During the tests, the permitted error tolerance is 0.01 cm. The graph plots show that the algorithm is fit for the error tolerance.展开更多
Teaching robotics necessarily involves the study of the kinematic models of robot manipulators. In turn, the kinematics of a robot manipulator can be described by its forward and reverse models. The inverse kinematic ...Teaching robotics necessarily involves the study of the kinematic models of robot manipulators. In turn, the kinematics of a robot manipulator can be described by its forward and reverse models. The inverse kinematic model, which provides the status of the joints according to the desired position for the tool of the robot, is typically taught and described in robotics classes through an algebraic way. However, the algebraic representation of this model is often difficult to obtain. Thus, although it is unquestionable the need for the accurate determination of the inverse kinematic model of a robot, the use of ANNs （artificial neural networks） in the design stage can be very attractive, because it allows us to predict the behavior of the robot before the formal development of its model. In this way, this paper presents a relatively quick way to simulate the inverse kinematic model of a robot, thereby allowing the student to have an overview of the model, coming to identify points that should be corrected, or that can be optimized in the structure of a robot.展开更多
A five-axis serial-parallel kinematic milling machine, the SPKM 165, is introduced. This machine consists of a three-degree of-freedom parallel module and a two-degree-of-freedom serial table. The SPKM 165 is capable ...A five-axis serial-parallel kinematic milling machine, the SPKM 165, is introduced. This machine consists of a three-degree of-freedom parallel module and a two-degree-of-freedom serial table. The SPKM 165 is capable of five-face machining. A discussion of the inverse kinematics of the five-axis control is provided. A dimensional synthesis procedure is presented in terms of motion/force transmissibility. Finite-element analysis was used to evaluate the stiffness of a CAD model before the machine was manufactured. Kinematic calibration was implemented to improve the accuracy of the end effector. The results of a calibration experiment are presented. The stiffness of the developed machine was then measured. Milling experiments were conducted, and the test piece showed that the developed machine has satisfactory performance.展开更多
基金Sponsored by the National Natural Science Foundation of China(Grant No.50975059)the National High-Tech Research and Development Program of China(863 Program)(Grant No.2006AA04Z231)+1 种基金the College Discipline Innovation Wisdom Plan(Grant No.B07018)Development Program of the Excellent Youth Scholars of Harbin Institute of Technology(Grant No.CACZ98504837)
文摘A new kind of eight-wheel lunar rover is developed, which is a complex closed-chain system and has good capabilities of climbing slope, surmounting obstacles and adapting to uneven terrain. In this paper, the mechanical structure of the novel eight-wheel lunar rover is introduced, forward and inverse kinematic models of the rover are established according to the closed-chain coordinate transformation and instantaneous coincidence coordinate. Based on structural characteristics, its kinetic characteristics are analyzed. Wheel slippages are separated and calculated, and a method for closed-loop control modification using wheel slip estimation during the model establishment is proposed. The results can be applied to the motion control of lunar rover.
文摘In this study, we aim at obtaining inverse kinematic model of a serial manipulator using spatial operator algebra. For testing the inverse kinematic algorithm, the Vpython software program which has simultaneous view and software working, is used. The aim is to measure the inverse kinematics modeling work on different serial manipulator mechanisms with spatial vector algebra. The algorithm is used with the same reference inputs on the recursive, exact and nonrecursive manipulators. During the tests, the permitted error tolerance is 0.01 cm. The graph plots show that the algorithm is fit for the error tolerance.
文摘Teaching robotics necessarily involves the study of the kinematic models of robot manipulators. In turn, the kinematics of a robot manipulator can be described by its forward and reverse models. The inverse kinematic model, which provides the status of the joints according to the desired position for the tool of the robot, is typically taught and described in robotics classes through an algebraic way. However, the algebraic representation of this model is often difficult to obtain. Thus, although it is unquestionable the need for the accurate determination of the inverse kinematic model of a robot, the use of ANNs （artificial neural networks） in the design stage can be very attractive, because it allows us to predict the behavior of the robot before the formal development of its model. In this way, this paper presents a relatively quick way to simulate the inverse kinematic model of a robot, thereby allowing the student to have an overview of the model, coming to identify points that should be corrected, or that can be optimized in the structure of a robot.
基金supported in part by the National Natural Science Foundation of China (Grant No. 51075222)the Fund of State Key Laboratory of Tribology (Grant No. SKLT10C02)
文摘A five-axis serial-parallel kinematic milling machine, the SPKM 165, is introduced. This machine consists of a three-degree of-freedom parallel module and a two-degree-of-freedom serial table. The SPKM 165 is capable of five-face machining. A discussion of the inverse kinematics of the five-axis control is provided. A dimensional synthesis procedure is presented in terms of motion/force transmissibility. Finite-element analysis was used to evaluate the stiffness of a CAD model before the machine was manufactured. Kinematic calibration was implemented to improve the accuracy of the end effector. The results of a calibration experiment are presented. The stiffness of the developed machine was then measured. Milling experiments were conducted, and the test piece showed that the developed machine has satisfactory performance.
