It is crucial for implementing force/position control of robotic manipulator under the constraint of unknown environment to determine the force control and the position control directions. This paper presents an on l...It is crucial for implementing force/position control of robotic manipulator under the constraint of unknown environment to determine the force control and the position control directions. This paper presents an on line algorithm to real timely estimate the tangent and the normal vectors of the constraint surface based on the measured contact force under the consideration of frictional force. A fuzzy synthesis policy is proposed to coordinate the conflict between the compliant force control and the stiff position control. An experimental study on an AdeptThree, a SCARA type robotic manipulator, is conducted. The experimental results show that the policy presented in the paper is effective.展开更多
This paper studies the dynamics of multiarm robots and multirobot configuration. With two or more arms holding an object, one or more closed loops are formed by the arms. The system is then a constrained multibody sys...This paper studies the dynamics of multiarm robots and multirobot configuration. With two or more arms holding an object, one or more closed loops are formed by the arms. The system is then a constrained multibody system and is studied as such. Dynamic analyses of constrained multibody systems may be obtained using recently developed procedures based upon Kane′s equations and Huston′s methods. These procedures lead to a numerical formulation of the governing equations, thus producing a simulation of the movement of the system. The procedures are applied and illustrated with a two robot system using PUMA 760 and 562 robots. A good agreement is obtained between theoretical and experimental results.展开更多
Extensively studied since the early nineties,cable-driven robots have attracted the growing interest of the industrial and scientific community due to their desirable and peculiar attributes.In particular,underconstra...Extensively studied since the early nineties,cable-driven robots have attracted the growing interest of the industrial and scientific community due to their desirable and peculiar attributes.In particular,underconstrained and planar cable robots can find application in several fields,and specifically,in the packaging industry.The planning of dynamically feasible trajectories(i.e.,trajectories along which cable slackness and excessive tensions are avoided) is particularly challenging when dealing with such a topology of cable robots,which rely on gravity to maintain their cables in tension.This paper,after stressing the current relevance of cable robots,presents an extension and a generalization of a model-based method developed to translate typical cable tension bilateral bounds into intuitive limits on the velocity and acceleration of the robot end effector along a prescribed path.Such a new formulation of the method is based on a parametric expression of cable tensions.The computed kinematic limits can then be incorporated into any trajectory planning algorithm.The method is developed with reference to a hybrid multi-body cable robot topology which can be functionally advantageous but worsen the problem of keeping feasible tensions in the cables both in static and dynamic conditions.The definition of statically feasible workspace is also introduced to identify the positions where static equilibrium can be maintained with feasible tensions.Finally,some aspects related to the practical implementation of the method are discussed.展开更多
文摘It is crucial for implementing force/position control of robotic manipulator under the constraint of unknown environment to determine the force control and the position control directions. This paper presents an on line algorithm to real timely estimate the tangent and the normal vectors of the constraint surface based on the measured contact force under the consideration of frictional force. A fuzzy synthesis policy is proposed to coordinate the conflict between the compliant force control and the stiff position control. An experimental study on an AdeptThree, a SCARA type robotic manipulator, is conducted. The experimental results show that the policy presented in the paper is effective.
文摘This paper studies the dynamics of multiarm robots and multirobot configuration. With two or more arms holding an object, one or more closed loops are formed by the arms. The system is then a constrained multibody system and is studied as such. Dynamic analyses of constrained multibody systems may be obtained using recently developed procedures based upon Kane′s equations and Huston′s methods. These procedures lead to a numerical formulation of the governing equations, thus producing a simulation of the movement of the system. The procedures are applied and illustrated with a two robot system using PUMA 760 and 562 robots. A good agreement is obtained between theoretical and experimental results.
基金supported by the Universita degli Studi di Padova under Grant No.CPDA088355/08
文摘Extensively studied since the early nineties,cable-driven robots have attracted the growing interest of the industrial and scientific community due to their desirable and peculiar attributes.In particular,underconstrained and planar cable robots can find application in several fields,and specifically,in the packaging industry.The planning of dynamically feasible trajectories(i.e.,trajectories along which cable slackness and excessive tensions are avoided) is particularly challenging when dealing with such a topology of cable robots,which rely on gravity to maintain their cables in tension.This paper,after stressing the current relevance of cable robots,presents an extension and a generalization of a model-based method developed to translate typical cable tension bilateral bounds into intuitive limits on the velocity and acceleration of the robot end effector along a prescribed path.Such a new formulation of the method is based on a parametric expression of cable tensions.The computed kinematic limits can then be incorporated into any trajectory planning algorithm.The method is developed with reference to a hybrid multi-body cable robot topology which can be functionally advantageous but worsen the problem of keeping feasible tensions in the cables both in static and dynamic conditions.The definition of statically feasible workspace is also introduced to identify the positions where static equilibrium can be maintained with feasible tensions.Finally,some aspects related to the practical implementation of the method are discussed.
