Deformable Linear Objects (DLOs) such as ropes, cables, and surgical sutures have a wide variety ... more Deformable Linear Objects (DLOs) such as ropes, cables, and surgical sutures have a wide variety of uses in automotive engineering, surgery, and electromechanical industries. Therefore, modeling of DLOs as well as a computationally efficient way to predict the DLO behavior are of great importance, in particular to enable robotic manipulation of DLOs. The main motivation of this work is to enable efficient pre- diction of the DLO behavior during robotic manipulation. In this paper, the DLO is modeled by a multivariate dynamic spline, while a symplectic integration method is used to solve the model iteratively by interpolating the DLO shape during the manipulation process. Comparisons between the symplectic, Runge-Kutta and Zhai integrators are reported. The presented results show the capabilities of the symplectic integrator to overcome other integration methods in predicting the DLO behavior. Moreover, the results obtained with different sets of model parameters integrated by means ...
This paper presents experimental results developed within the WIRES experiment, whose main object... more This paper presents experimental results developed within the WIRES experiment, whose main objective is the robotized cabling of switchgears. This task is currently executed by human operators; the WIRES Project tackles the development of a suitably designed sensorized end effector for the wire precise manipulation. In particular, the developed gripper with tactile sensors are shown and a procedure for the implementation of the insertion task is presented and discussed. Experimental results are reported both for quality of wire shape reconstruction and success rate of insertion task implementation.
The preliminary experimental study toward the implementation of an arm rehabilitation device base... more The preliminary experimental study toward the implementation of an arm rehabilitation device based on a twisted string actuation module is presented. The actuation module is characterized by an integrated force sensor based on optoelectronic components. The adopted actuation system can be used for a wide set of robotic applications and is particularly suited for very compact, light-weight, and wearable robotic devices, such as wearable rehabilitation systems and exoskeletons. Thorough presentation and description of the proposed actuation module as well as the basic force sensor working principle are illustrated and discussed. A conceptual design of a wearable arm assistive system based on the proposed actuation module is presented. Moreover, the actuation module has been used in a simple assistive application, in which surface-electromyography signals are used to detect muscle activity of the user wearing the system and to regulate the support action provided to the user to reduce ...
... Tags. Realtime hardware emulation for rapid prototyping and testing of digital control system... more ... Tags. Realtime hardware emulation for rapid prototyping and testing of digital control systems. by: Gianluca Palli. RIS, Export as RIS which can be imported into most citation managers. BibTeX, Export as BibTeX which can be imported into most citation/bibliography managers. ...
Abstract: In this paper, the tendon-sheath driving system for a robotic hand is discussed and its... more Abstract: In this paper, the tendon-sheath driving system for a robotic hand is discussed and its force transmission characteristic analyzed. The use of tendons permits to reduce the size and the complexity of the actuation chain in many mechanical devices but, on the other hand, ...
International Journal of Robotics and Automation, 2014
ABSTRACT In this paper, the force sensor developed for the so called twisted string actuation sys... more ABSTRACT In this paper, the force sensor developed for the so called twisted string actuation system of the DEXMART Hand is described. The proposed solution makes use of optoelectronic components for measuring the deformation of a properly designed motor module structure caused by the force applied on the transmission system. The paper reports a detailed overview of the motor module design, of the integrated force sensor, the basic sensor working principle and the optimization both of the flexible structure and of the optoelectronic components positioning. Moreover, the proposed sensor has been used for controlling a complete robotic finger: the results of the experiments that show the performance of the DEXMART Hand actuation force control system using the force sensor described in this paper is reported.
ABSTRACT In this paper, the experimental evaluation of fine manipulation tasks executed by the DE... more ABSTRACT In this paper, the experimental evaluation of fine manipulation tasks executed by the DEXMART Hand is presented. The robotic hand is characterized by a compliant actuation system and soft contact interfaces. The manipulation is controlled by feedback information acquired by optoelectronic tactile sensors integrated into the fingertips of the robotic hand. An impedance-like control scheme has been implemented to allow the simultaneous control of the finger positions and contact forces, thus preventing position drift caused by asymmetric force measurement between different sensors. This approach allows also to decouple the control of the normal force applied to the object to prevent slip from the control of the tangential forces applied to the object surface to perform manipulation. Moreover, the evaluation of manipulation tasks of soft objects with variable weight is presented to show the ability of the system to hold the object by applying the minimum required normal force to prevent slip. The performance evaluation has been carried out by considering fine manipulation tasks executed with a simplified setup composed by two opposed fingers, and manipulation tasks of various objects involving the whole DEXMART Hand are presented, as a demonstration of the device capabilities.
Volume 1: Development and Characterization of Multifunctional Materials; Modeling, Simulation and Control of Adaptive Systems; Integrated System Design and Implementation, 2013
ABSTRACT Artificial Muscles based on Dielectric Elastomers (DE) can potentially enable the realiz... more ABSTRACT Artificial Muscles based on Dielectric Elastomers (DE) can potentially enable the realization of bio-inspired actuation systems whose intrinsic compliance and damping can be varied according to the task requirements. Nonetheless, the control of DE-based Variable Impedance Actuators (VIA) is not trivial owing to the non-linear viscoelastic response which characterizes the acrylic dielectrics commonly employed in practical devices.In this context, the purpose of the present paper is to outline a novel strategy for the control of DE-based VIA. Although the proposed methodology is applicable to generic DE morphologies, the considered system is composed of a couple of conically-shaped DE films in agonistic-antagonistic configuration. Following previously published results, the system dynamic model is firstly recalled. Then, a DE viscoelasticity compensation technique is outlined together with a control law able to shape the DE actuator impedance as desired. The operative limits of the system are explicitly considered and managed in the controller by increasing the operating DE actuator stiffness if required. In addition, the problem of model uncertainties compensation is also addressed. Finally, as a preliminary step towards the realization of a practical DE-based VIA, the proposed control approach is validated by means of simulations.
Deformable Linear Objects (DLOs) such as ropes, cables, and surgical sutures have a wide variety ... more Deformable Linear Objects (DLOs) such as ropes, cables, and surgical sutures have a wide variety of uses in automotive engineering, surgery, and electromechanical industries. Therefore, modeling of DLOs as well as a computationally efficient way to predict the DLO behavior are of great importance, in particular to enable robotic manipulation of DLOs. The main motivation of this work is to enable efficient pre- diction of the DLO behavior during robotic manipulation. In this paper, the DLO is modeled by a multivariate dynamic spline, while a symplectic integration method is used to solve the model iteratively by interpolating the DLO shape during the manipulation process. Comparisons between the symplectic, Runge-Kutta and Zhai integrators are reported. The presented results show the capabilities of the symplectic integrator to overcome other integration methods in predicting the DLO behavior. Moreover, the results obtained with different sets of model parameters integrated by means ...
This paper presents experimental results developed within the WIRES experiment, whose main object... more This paper presents experimental results developed within the WIRES experiment, whose main objective is the robotized cabling of switchgears. This task is currently executed by human operators; the WIRES Project tackles the development of a suitably designed sensorized end effector for the wire precise manipulation. In particular, the developed gripper with tactile sensors are shown and a procedure for the implementation of the insertion task is presented and discussed. Experimental results are reported both for quality of wire shape reconstruction and success rate of insertion task implementation.
The preliminary experimental study toward the implementation of an arm rehabilitation device base... more The preliminary experimental study toward the implementation of an arm rehabilitation device based on a twisted string actuation module is presented. The actuation module is characterized by an integrated force sensor based on optoelectronic components. The adopted actuation system can be used for a wide set of robotic applications and is particularly suited for very compact, light-weight, and wearable robotic devices, such as wearable rehabilitation systems and exoskeletons. Thorough presentation and description of the proposed actuation module as well as the basic force sensor working principle are illustrated and discussed. A conceptual design of a wearable arm assistive system based on the proposed actuation module is presented. Moreover, the actuation module has been used in a simple assistive application, in which surface-electromyography signals are used to detect muscle activity of the user wearing the system and to regulate the support action provided to the user to reduce ...
... Tags. Realtime hardware emulation for rapid prototyping and testing of digital control system... more ... Tags. Realtime hardware emulation for rapid prototyping and testing of digital control systems. by: Gianluca Palli. RIS, Export as RIS which can be imported into most citation managers. BibTeX, Export as BibTeX which can be imported into most citation/bibliography managers. ...
Abstract: In this paper, the tendon-sheath driving system for a robotic hand is discussed and its... more Abstract: In this paper, the tendon-sheath driving system for a robotic hand is discussed and its force transmission characteristic analyzed. The use of tendons permits to reduce the size and the complexity of the actuation chain in many mechanical devices but, on the other hand, ...
International Journal of Robotics and Automation, 2014
ABSTRACT In this paper, the force sensor developed for the so called twisted string actuation sys... more ABSTRACT In this paper, the force sensor developed for the so called twisted string actuation system of the DEXMART Hand is described. The proposed solution makes use of optoelectronic components for measuring the deformation of a properly designed motor module structure caused by the force applied on the transmission system. The paper reports a detailed overview of the motor module design, of the integrated force sensor, the basic sensor working principle and the optimization both of the flexible structure and of the optoelectronic components positioning. Moreover, the proposed sensor has been used for controlling a complete robotic finger: the results of the experiments that show the performance of the DEXMART Hand actuation force control system using the force sensor described in this paper is reported.
ABSTRACT In this paper, the experimental evaluation of fine manipulation tasks executed by the DE... more ABSTRACT In this paper, the experimental evaluation of fine manipulation tasks executed by the DEXMART Hand is presented. The robotic hand is characterized by a compliant actuation system and soft contact interfaces. The manipulation is controlled by feedback information acquired by optoelectronic tactile sensors integrated into the fingertips of the robotic hand. An impedance-like control scheme has been implemented to allow the simultaneous control of the finger positions and contact forces, thus preventing position drift caused by asymmetric force measurement between different sensors. This approach allows also to decouple the control of the normal force applied to the object to prevent slip from the control of the tangential forces applied to the object surface to perform manipulation. Moreover, the evaluation of manipulation tasks of soft objects with variable weight is presented to show the ability of the system to hold the object by applying the minimum required normal force to prevent slip. The performance evaluation has been carried out by considering fine manipulation tasks executed with a simplified setup composed by two opposed fingers, and manipulation tasks of various objects involving the whole DEXMART Hand are presented, as a demonstration of the device capabilities.
Volume 1: Development and Characterization of Multifunctional Materials; Modeling, Simulation and Control of Adaptive Systems; Integrated System Design and Implementation, 2013
ABSTRACT Artificial Muscles based on Dielectric Elastomers (DE) can potentially enable the realiz... more ABSTRACT Artificial Muscles based on Dielectric Elastomers (DE) can potentially enable the realization of bio-inspired actuation systems whose intrinsic compliance and damping can be varied according to the task requirements. Nonetheless, the control of DE-based Variable Impedance Actuators (VIA) is not trivial owing to the non-linear viscoelastic response which characterizes the acrylic dielectrics commonly employed in practical devices.In this context, the purpose of the present paper is to outline a novel strategy for the control of DE-based VIA. Although the proposed methodology is applicable to generic DE morphologies, the considered system is composed of a couple of conically-shaped DE films in agonistic-antagonistic configuration. Following previously published results, the system dynamic model is firstly recalled. Then, a DE viscoelasticity compensation technique is outlined together with a control law able to shape the DE actuator impedance as desired. The operative limits of the system are explicitly considered and managed in the controller by increasing the operating DE actuator stiffness if required. In addition, the problem of model uncertainties compensation is also addressed. Finally, as a preliminary step towards the realization of a practical DE-based VIA, the proposed control approach is validated by means of simulations.
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