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Stefano Chiaverini - One of the best experts on this subject based on the ideXlab platform.
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Stability analysis of a joint space control law for a two-manipulator system
IEEE Transactions on Automatic Control, 1999Co-Authors: Fabrizio Caccavale, Pasquale Chiacchio, Stefano ChiaveriniAbstract:The control problem for a truly cooperative manipulator system cannot be regarded as a simple extension of single manipulator control since additional complexity arises from the need for ensuring coordinated motion of the system. Recently, we have proposed a control strategy based on two stages, namely, kinematic inversion of a set of cooperative task variables and a joint space control law with kinetostatic filtering of cooperative task space errors; this strategy avoids some of the drawbacks of other approaches. In this paper, the stability analysis for the joint space control law is provided and asymptotic stability of a set of equilibrium points is demonstrated. The case of imperfect compensation of the gravity terms has been analyzed. The addition of a Force Loop to achieve internal Force regulation is also discussed.
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Force/position regulation of compliant robot manipulators
IEEE Transactions on Automatic Control, 1994Co-Authors: Stefano Chiaverini, Bruno Siciliano, Luigi VillaniAbstract:Stable Force/position regulation of robot manipulators in contact with an elastically compliant surface is discussed in this work. The controller consists of a PD action on the position Loop, a PI action on the Force Loop, together with gravity compensation and desired contact Force feedforward. Asymptotic stability of the system in the neighborhood of the equilibrium state is proven via the classical Lyapunov method with LaSalle invariant set theorem. A modification of the Lyapunov function leads to deriving an exponential stability result. Numerical case studies are developed for an industrial manipulator. >
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A stable Force/position controller for robot manipulators
[1992] Proceedings of the 31st IEEE Conference on Decision and Control, 1Co-Authors: Stefano Chiaverini, Bruno Siciliano, Luigi VillaniAbstract:A Force/position controller for robot manipulators in contact with an elasticity compliant surface is presented. The controller consists of proportional-derivative (PD) action on the position Loop and proportional-integral (PI) action on the Force Loop, together with gravity compensation and desired contact Force feedforward. Asymptotic stability of the system in the neighborhood of the equilibrium state is proven via the classical Lyapunov method with the LaSalle invariance set theorem. A modification of the Lyapunov function leads to deriving an exponential stability result. >
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Stability analysis of 6-DOF Force/position control for robot manipulators
Proceedings of 1994 33rd IEEE Conference on Decision and Control, 1Co-Authors: Jan Tommy Gravdahl, Bruno Siciliano, Olav Egeland, Stefano ChiaveriniAbstract:In this paper we propose a Force/position control scheme in a 6-DOF task space which is a generalization of the parallel control scheme in a 3-DOF task space. The controller consists of a PD action on the position Loop, a PI action on the Force Loop together with gravity compensation and feedforward of the desired contact Force. Kinestatic filtering is not used in the scheme. Euler parameters are adopted to describe end-effector orientation. The model of interaction wrench (Force and moment) is formulated with a generalized spring. Stability of the proposed scheme is established through the Lyapunov method. >
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Stability analysis of a joint space control law for a two-manipulator system
Proceedings of 35th IEEE Conference on Decision and Control, 1Co-Authors: Fabrizio Caccavale, Pasquale Chiacchio, Stefano ChiaveriniAbstract:The control problem for a truly cooperative manipulator system cannot be regarded as a simple extension of single manipulator control since additional complexity arises from the need of ensuring coordinated motion of the system. Previously, we have proposed a control strategy based on two stages; namely, kinematic inversion of a set of cooperative task variables, and a joint space control law with kinetostatic filtering of cooperative task space errors; this strategy avoids some of the drawbacks of other approaches. In this paper, the stability analysis for the joint space control law is provided and global asymptotic stability of a set of equilibrium points is demonstrated. The addition of a Force Loop to achieve internal Force regulation is also discussed.
Harvey R. Weiss - One of the best experts on this subject based on the ideXlab platform.
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An experimental technique for estimating regional myocardial segment work in vivo.
Annals of biomedical engineering, 1994Co-Authors: J. Kedem, Wen Wha Lee, Harvey R. WeissAbstract:We determined the capabilities and limitations of an experimental approach to measure segment work (Force × distance) of myocardial regions in thein vivo beating heart. In 18 open-chest anesthetized dogs, segment length was measured using ultrasonic dimension transducers, and developed Force was measured with miniature Force transducers. Work was defined as the integrated multiples of instantaneous Force and shortening during a single (averaged) beat, corresponding to the area under the length-Force Loop. Changes in work over a range of 9.78×10−4 to 2.93×10−2 J/g/min were produced by vena caval constriction, aortic constriction, atrial pacing, and isoproterenol (0.5 and 1.0 μg/kg/min). Work was measured in both major and minor axes. In 60% of the animals, work in the minor axis was 9.2-fold greater than in the major axis. In the others, all interventions changed regional work to the same extent in both axes (r=0.802; p
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An experimental technique for estimating regional myocardial segment workIn Vivo
Annals of Biomedical Engineering, 1994Co-Authors: Joseph Kedem, Wen Wha Lee, Harvey R. WeissAbstract:We determined the capabilities and limitations of an experimental approach to measure segment work (Force × distance) of myocardial regions in the in vivo beating heart. In 18 open-chest anesthetized dogs, segment length was measured using ultrasonic dimension transducers, and developed Force was measured with miniature Force transducers. Work was defined as the integrated multiples of instantaneous Force and shortening during a single (averaged) beat, corresponding to the area under the length-Force Loop. Changes in work over a range of 9.78×10^−4 to 2.93×10^−2 J/g/min were produced by vena caval constriction, aortic constriction, atrial pacing, and isoproterenol (0.5 and 1.0 μg/kg/min). Work was measured in both major and minor axes. In 60% of the animals, work in the minor axis was 9.2-fold greater than in the major axis. In the others, all interventions changed regional work to the same extent in both axes ( r =0.802; p
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Effect of isoproterenol on regional myocardial segment work, O_2 consumption, and oxygen balance
Research in Experimental Medicine, 1992Co-Authors: J. Kedem, J. Sonn, M. Scheinowitz, Harvey R. WeissAbstract:We tested the hypothesis that positive inotropic stimulation by isoproterenol alters the relationship between regional segment work and regional myocardial oxygen consumption. Regional parameters were compared with external cardiac work and global LV oxygen consumption. In anesthetized openchest dogs, regional myocardial segment length (ultrasonic dimension crystals) and Force development (miniature Force transducer) were measured. The integrated multiples of myocardial shortening by corresponding Force during an averaged beat expressed segment work (area under the systolic portion of the length-Force Loop). External cardiac work was calculated from aortic blood pressure and cardiac output. Global and regional myocardial MVO_2 were evaluated at baseline and during intravenous infusion of isoproterenol (0.5 and 1.0 μg/kg per min). Regional coronary blood flow was measured with radioactive microspheres, and microspectrophotometry of frozen myocardial biopsies was used to evaluate O_2 saturation in small arteries and veins. These parameters were used to calculate regional MVO_2. Arterial and coronary sinus O_2 saturation was used to calculate global LV O_2 consumption. Regional myocardial O_2 balance was estimated by measurement of NADH redox level using surface fluorometry. It was found that 0.5 μg/kg per min isoproterenol increased regional segment work/minute from 4650±495 to 6750±750 mm·g/min. Corresponding regional oxygen consumption was disproportionately increased from 5.43±0.61 to 15.24±1.37 ml/min per 100 g. External cardiac work was found to decrease from 728±13 to 562±25 mmHg·1/min (due to decreased aortic blood pressure), whereas global myocardial O_2 consumption increased. Regional myocardial O_2 extraction and NADH fluorescence were elevated, indicating impaired tissue oxygenation. Regional MVO_2 was increased by 153±56%, but regional work by only 45.3±33% ( P
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Augmented efficiency of regional myocardial work by ouabain.
Cardiovascular research, 1991Co-Authors: J. Kedem, Peter M. Scholtz, Harvey R. WeissAbstract:Study objective — The effect of ouabain on regional myocardial mechanics and corresponding regional myocardial oxygen consumption was investigated. Design — Regional myocardial segment length (ultrasonic dimension crystals) and Force development (miniature strain gauge) were measured. The integrated multiples of myocardial shortening by corresponding Force during an averaged beat was used to express regional segment work (= area under the systolic portion of the length-Force Loop). External cardiac work was calculated from aortic blood pressure and cardiac output. Global and regional myocardial O2 consumption (MVO2) were evaluated at baseline and during intravenous infusion of ouabain (7 μg·kg−1·min−1). Regional coronary blood flow was measured with radioactive microspheres, and microspectrophotometry of frozen myocardial biopsies was used to evaluate O2 saturation in small arteries and veins. These variables were used to calculate regional myocardial MVO2. Arterial and coronary sinus O2 saturation was used to calculate global left ventricular O2 consumption. Myocardial efficiency was expressed as regional work/regional myocardial MVO2. Subjects — Ten open chest anaesthetised dogs, weight about 20 kg, were used. Measurements and main results — Ouabain increased regional myocardial segment work [from 5291(SEM 1067) to 8916(2338) mm·g−1·min−1] to a greater extent than regional myocardial MVO2 [from 6.33(0.75) to 8.54(0.75) ml O2·min−1·100 g−1]. Regional efficiency was increased from 734(78) to 1036(160) g·mm·ml O2−1·100 g−1. External efficiency was not raised. Percent shortening was increased to a greater extent than peak Force development (+76% v +38%), possibly indicating increased myocardial compliance. The length-Force Loop was shifted upward and to the right. Conclusions — Ouabain increases regional efficiency of myocardial contraction.
Fabrizio Caccavale - One of the best experts on this subject based on the ideXlab platform.
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Stability analysis of a joint space control law for a two-manipulator system
IEEE Transactions on Automatic Control, 1999Co-Authors: Fabrizio Caccavale, Pasquale Chiacchio, Stefano ChiaveriniAbstract:The control problem for a truly cooperative manipulator system cannot be regarded as a simple extension of single manipulator control since additional complexity arises from the need for ensuring coordinated motion of the system. Recently, we have proposed a control strategy based on two stages, namely, kinematic inversion of a set of cooperative task variables and a joint space control law with kinetostatic filtering of cooperative task space errors; this strategy avoids some of the drawbacks of other approaches. In this paper, the stability analysis for the joint space control law is provided and asymptotic stability of a set of equilibrium points is demonstrated. The case of imperfect compensation of the gravity terms has been analyzed. The addition of a Force Loop to achieve internal Force regulation is also discussed.
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Stability analysis of a joint space control law for a two-manipulator system
Proceedings of 35th IEEE Conference on Decision and Control, 1Co-Authors: Fabrizio Caccavale, Pasquale Chiacchio, Stefano ChiaveriniAbstract:The control problem for a truly cooperative manipulator system cannot be regarded as a simple extension of single manipulator control since additional complexity arises from the need of ensuring coordinated motion of the system. Previously, we have proposed a control strategy based on two stages; namely, kinematic inversion of a set of cooperative task variables, and a joint space control law with kinetostatic filtering of cooperative task space errors; this strategy avoids some of the drawbacks of other approaches. In this paper, the stability analysis for the joint space control law is provided and global asymptotic stability of a set of equilibrium points is demonstrated. The addition of a Force Loop to achieve internal Force regulation is also discussed.
Ribin Balachandran - One of the best experts on this subject based on the ideXlab platform.
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closing the Force Loop to enhance transparency in time delayed teleoperation
International Conference on Robotics and Automation, 2020Co-Authors: Ribin Balachandran, Jeehwan Ryu, Mikael Jorda, Christian Ott, Alin AlbuschaefferAbstract:In the present paper, we first adopt explicit Force control from general robotics and embed it into teleoperation systems to enhance the transparency by reducing the effect of the perceived inertia to the human operator and simultaneously improve contact perception. To ensure stability of the proposed teleoperation system considering time-delays, we propose a sequential design procedure based on time domain passivity approach. Experimental results of master-slave teleoperation system, based on KUKA light-weight-robots, for different values of delays are presented. Comparative analysis is conducted considering two existing approaches, namely 2-channel and 4-channel architecture based bilateral controllers, and its results clearly indicate significant improvement in Force transparency owing to the proposed method. The proposed system is finally validated considering a real industrial assembly scenario.
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ICRA - Closing the Force Loop to Enhance Transparency in Time-delayed Teleoperation
2020 IEEE International Conference on Robotics and Automation (ICRA), 2020Co-Authors: Ribin Balachandran, Jeehwan Ryu, Mikael Jorda, Christian Ott, Alin Albu-schaefferAbstract:In the present paper, we first adopt explicit Force control from general robotics and embed it into teleoperation systems to enhance the transparency by reducing the effect of the perceived inertia to the human operator and simultaneously improve contact perception. To ensure stability of the proposed teleoperation system considering time-delays, we propose a sequential design procedure based on time domain passivity approach. Experimental results of master-slave teleoperation system, based on KUKA light-weight-robots, for different values of delays are presented. Comparative analysis is conducted considering two existing approaches, namely 2-channel and 4-channel architecture based bilateral controllers, and its results clearly indicate significant improvement in Force transparency owing to the proposed method. The proposed system is finally validated considering a real industrial assembly scenario.
Alin Albuschaeffer - One of the best experts on this subject based on the ideXlab platform.
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closing the Force Loop to enhance transparency in time delayed teleoperation
International Conference on Robotics and Automation, 2020Co-Authors: Ribin Balachandran, Jeehwan Ryu, Mikael Jorda, Christian Ott, Alin AlbuschaefferAbstract:In the present paper, we first adopt explicit Force control from general robotics and embed it into teleoperation systems to enhance the transparency by reducing the effect of the perceived inertia to the human operator and simultaneously improve contact perception. To ensure stability of the proposed teleoperation system considering time-delays, we propose a sequential design procedure based on time domain passivity approach. Experimental results of master-slave teleoperation system, based on KUKA light-weight-robots, for different values of delays are presented. Comparative analysis is conducted considering two existing approaches, namely 2-channel and 4-channel architecture based bilateral controllers, and its results clearly indicate significant improvement in Force transparency owing to the proposed method. The proposed system is finally validated considering a real industrial assembly scenario.