ABSTRACT A complete solution for problems of vibration control in structures that may be subject ... more ABSTRACT A complete solution for problems of vibration control in structures that may be subject to a broadband primary vibration field, this book addresses the following steps: experimental identification of the dynamic model of the structure; optimal placement of sensors and actuators; formulation of control constraints in terms of controller frequency response shape; controller design and simulation; and controller implementation and rapid prototyping. The identification procedure is a gray-box approach tailored to the estimation of modal parameters of large-scale flexible structures. The actuator/sensor placement algorithm maximizes a modal controllability index improving the effectiveness of the control. Considering limitations of sensors and actuators, the controller is chosen as a stable, band-pass MIMO system resulting from the closed-form solution of a robust control problem. Experimental results on an aeronautical stiffened skin panel are presented using rapid-prototyping hardware.
This paper proposes an experimental study of slipping avoidance algorithms based on force/tactile... more This paper proposes an experimental study of slipping avoidance algorithms based on force/tactile perception data. The claim is that contact force measurements alone or tactile data alone are not sufficient for an effective slipping avoidance strategy in real world conditions. Integrated force/tactile sensors able to provide measurements of both the contact force vector and spatially distributed tactile maps are the key enabling technology for efficient slipping avoidance control algorithms that can actually work with real world objects under no restricting assumption on the contact geometry or with unknown physical properties of the objects. The paper proposes a new slipping avoidance control scheme, which usefully exploits an integrated force/tactile sensor mounted on the parallel gripper of a Kuka youBot. The results show how the strategy successfully allows the robot to safely manipulate real-world objects, both rigid and compliant, in various friction conditions of their surfac...
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.
2001 IEEE/ASME International Conference on Advanced Intelligent Mechatronics. Proceedings (Cat. No.01TH8556), 2001
ABSTRACT Proposes the compensation of the hysteretic behaviour of an actuator constituted by a Te... more ABSTRACT Proposes the compensation of the hysteretic behaviour of an actuator constituted by a Terfenol-D magnetostrictive material to enhance the performance of a typical control scheme for vibration suppression. Hysteresis is modelled by the application of the classical Preisach model whose identification procedure is performed by the adoption of fuzzy approximators. This allows analytic reconstruction of Everett integrals and the Preisach distribution function, without any special smoothing of the measured data, thanks to the altering capabilities of the fuzzy interpolators. Moreover, the idea of compensator for operators with memory is also described in detail and the concept of pseudo-compensator is introduced. The latter operator allows approximation of the inverse of a given Preisach-like operator and then to easily compensate hysteresis and nonlinearity of a real magnetostrictive actuator
ABSTRACT In this paper, the problem of designing a force controller for industrial robots with a ... more ABSTRACT In this paper, the problem of designing a force controller for industrial robots with a positional interface is addressed. A systematic design procedure to compute structures and parameters of the controller is devised, to provide a useful tool for rapid and robust setup of force control at the industrial level. The proposed method for synthesis of the force controller simply requires technology parameters provided by the robot manufacturer and desired performance expressed in non-technical terms by the user. The automated design algorithm is described in detail and its effectiveness was proved by experiments on two different industrial robots. On the first robotic setup, the performance of the designed controllers was evaluated by analyzing the experimental results of responses to canonical reference signals; on the second setup, the controller reliability and applicability at the industrial level were demonstrated through the results of a mechanical parts mating task
ABSTRACT A complete solution for problems of vibration control in structures that may be subject ... more ABSTRACT A complete solution for problems of vibration control in structures that may be subject to a broadband primary vibration field, this book addresses the following steps: experimental identification of the dynamic model of the structure; optimal placement of sensors and actuators; formulation of control constraints in terms of controller frequency response shape; controller design and simulation; and controller implementation and rapid prototyping. The identification procedure is a gray-box approach tailored to the estimation of modal parameters of large-scale flexible structures. The actuator/sensor placement algorithm maximizes a modal controllability index improving the effectiveness of the control. Considering limitations of sensors and actuators, the controller is chosen as a stable, band-pass MIMO system resulting from the closed-form solution of a robust control problem. Experimental results on an aeronautical stiffened skin panel are presented using rapid-prototyping hardware.
ABSTRACT A complete solution for problems of vibration control in structures that may be subject ... more ABSTRACT A complete solution for problems of vibration control in structures that may be subject to a broadband primary vibration field, this book addresses the following steps: experimental identification of the dynamic model of the structure; optimal placement of sensors and actuators; formulation of control constraints in terms of controller frequency response shape; controller design and simulation; and controller implementation and rapid prototyping. The identification procedure is a gray-box approach tailored to the estimation of modal parameters of large-scale flexible structures. The actuator/sensor placement algorithm maximizes a modal controllability index improving the effectiveness of the control. Considering limitations of sensors and actuators, the controller is chosen as a stable, band-pass MIMO system resulting from the closed-form solution of a robust control problem. Experimental results on an aeronautical stiffened skin panel are presented using rapid-prototyping hardware.
This paper proposes an experimental study of slipping avoidance algorithms based on force/tactile... more This paper proposes an experimental study of slipping avoidance algorithms based on force/tactile perception data. The claim is that contact force measurements alone or tactile data alone are not sufficient for an effective slipping avoidance strategy in real world conditions. Integrated force/tactile sensors able to provide measurements of both the contact force vector and spatially distributed tactile maps are the key enabling technology for efficient slipping avoidance control algorithms that can actually work with real world objects under no restricting assumption on the contact geometry or with unknown physical properties of the objects. The paper proposes a new slipping avoidance control scheme, which usefully exploits an integrated force/tactile sensor mounted on the parallel gripper of a Kuka youBot. The results show how the strategy successfully allows the robot to safely manipulate real-world objects, both rigid and compliant, in various friction conditions of their surfac...
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.
2001 IEEE/ASME International Conference on Advanced Intelligent Mechatronics. Proceedings (Cat. No.01TH8556), 2001
ABSTRACT Proposes the compensation of the hysteretic behaviour of an actuator constituted by a Te... more ABSTRACT Proposes the compensation of the hysteretic behaviour of an actuator constituted by a Terfenol-D magnetostrictive material to enhance the performance of a typical control scheme for vibration suppression. Hysteresis is modelled by the application of the classical Preisach model whose identification procedure is performed by the adoption of fuzzy approximators. This allows analytic reconstruction of Everett integrals and the Preisach distribution function, without any special smoothing of the measured data, thanks to the altering capabilities of the fuzzy interpolators. Moreover, the idea of compensator for operators with memory is also described in detail and the concept of pseudo-compensator is introduced. The latter operator allows approximation of the inverse of a given Preisach-like operator and then to easily compensate hysteresis and nonlinearity of a real magnetostrictive actuator
ABSTRACT In this paper, the problem of designing a force controller for industrial robots with a ... more ABSTRACT In this paper, the problem of designing a force controller for industrial robots with a positional interface is addressed. A systematic design procedure to compute structures and parameters of the controller is devised, to provide a useful tool for rapid and robust setup of force control at the industrial level. The proposed method for synthesis of the force controller simply requires technology parameters provided by the robot manufacturer and desired performance expressed in non-technical terms by the user. The automated design algorithm is described in detail and its effectiveness was proved by experiments on two different industrial robots. On the first robotic setup, the performance of the designed controllers was evaluated by analyzing the experimental results of responses to canonical reference signals; on the second setup, the controller reliability and applicability at the industrial level were demonstrated through the results of a mechanical parts mating task
ABSTRACT A complete solution for problems of vibration control in structures that may be subject ... more ABSTRACT A complete solution for problems of vibration control in structures that may be subject to a broadband primary vibration field, this book addresses the following steps: experimental identification of the dynamic model of the structure; optimal placement of sensors and actuators; formulation of control constraints in terms of controller frequency response shape; controller design and simulation; and controller implementation and rapid prototyping. The identification procedure is a gray-box approach tailored to the estimation of modal parameters of large-scale flexible structures. The actuator/sensor placement algorithm maximizes a modal controllability index improving the effectiveness of the control. Considering limitations of sensors and actuators, the controller is chosen as a stable, band-pass MIMO system resulting from the closed-form solution of a robust control problem. Experimental results on an aeronautical stiffened skin panel are presented using rapid-prototyping hardware.
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