- Karolou 85e,
Patras, 26223,
Western Greece, Greece - +306977515092
Research Interests:
A method for determining the optimal position of a robotic task within a manipulator’s workspace considering the minimum singularity free paths in joint space in order to achieve a high kinematic performance is presented. The selected... more
A method for determining the optimal position of a robotic task within a manipulator’s workspace considering the minimum singularity free paths in joint space in order to achieve a high kinematic performance is presented. The selected performance criterion was the minimization of the joint velocities during task execution under a given end effector velocity. The proposed method is applied to place kinematic tasks for a UR-5 manipulator. Joint speed measurements are compared for the optimal and the “bad” task positions and the results show that at the optimal position, lower joint speeds are exerted during task execution.
Research Interests:
Research Interests:
The inherit complexity of the determination of the optimal anatomy and structure to task requirements and specification for metamorphic manipulators poses a significant challenge to the end user, as such methods and tools to undertake... more
The inherit complexity of the determination of the optimal anatomy and structure to task requirements and specification for metamorphic manipulators poses a significant challenge to the end user, as such methods and tools to undertake such processes are required for the implementation of metamorphic robots to real-life applications in various fields. In this work, the methodology for an offline process for the determination of the optimal anatomy maximizing performance under different requirements is presented. Such requirements considered in this work include the kinematic, kinetostatic and dynamic performance of the manipulator during task execution. The proposed methodology is then applied to a 3 D.o.F. metamorphic manipulator for different tasks. The presented results clearly show that a single metamorphic structure is able to provide the end user with different anatomies, each better suited to task specifications.
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The optimal positioning of tasks in robot applications is an extremely important step in the design of robotic work cells as it will allow the system to achieve the required high performance given the selected performance measure. In this... more
The optimal positioning of tasks in robot applications is an extremely important step in the design of robotic work cells as it will allow the system to achieve the required high performance given the selected performance measure. In this work the optimal positioning of a robotic task is presented with the aim to minimize the required joint velocities required during task execution, for a 6 D.o.F. manipulator. The method is used to determine the optimal location for a path following task in the workspace of a UR-5 manipulator. Results show that the optimal task placement allows for a significant reduction of joint velocities to maintain a given constant end effector velocity during task execution.
Research Interests:
Modular, reconfigurable, self-reconfigurable and metamorphic robots have already been in research since the last quarter of the previous century however and quite several different module designs have been presented in the relevant... more
Modular, reconfigurable, self-reconfigurable and metamorphic robots have already been in research since the last quarter of the previous century however and quite several different module designs have been presented in the relevant literature. As such, these modules need to be taxonomized and critically reviewed in order to form the basis for the design of new modules. The present paper introduces such a taxonomy based on the governing aspects of the modules in the literature and a weighted grading system for their critical review. Fifteen different module designs are examined and graded to identify their suitability for serving as the basis for the design of new modules for a self-metamorphic robotic manipulator system.
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ABSTRACT One of the most important tasks of the network of excellence INNOVATIVE PRODUCTION MACHINES AND SYSTEMS (NoE I*PROMS, www.iproms.org) is the joint collaborative review and evaluation of research trends in manufacturing and the... more
ABSTRACT One of the most important tasks of the network of excellence INNOVATIVE PRODUCTION MACHINES AND SYSTEMS (NoE I*PROMS, www.iproms.org) is the joint collaborative review and evaluation of research trends in manufacturing and the respective update of research roadmaps for industry and public research. This contribution presents an overview and the first results from a Delphi study conducted in this framework displaying the importance of actual and future research topics in manufacturing.
Research Interests:
Designing a reconfigurable manufacturing robotic workcell is a complex and resource demanding procedure. In this work a multi criteria index is introduced, allowing the designer to evaluate the various anatomies achieved by a... more
Designing a reconfigurable manufacturing robotic workcell is a complex and resource demanding procedure. In this work a multi criteria index is introduced, allowing the designer to evaluate the various anatomies achieved by a reconfigurable manipulator, and to define the area in the manipulator’s configuration space where a task can be accomplished with good performance under the selected performance measure. An
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Καθώς η παραγωγή προϊόντων στρέφεται προς τη λογική του mass customization, ψάχνοντας τρόπους ώστε να παράγονται προϊόντα ανταγωνιστικά και προσαρμοσμένα στις απαιτήσεις και ανάγκες των πελατών/ καταναλωτών, τα συστήματα παραγωγής... more
Καθώς η παραγωγή προϊόντων στρέφεται προς τη λογική του mass customization, ψάχνοντας τρόπους ώστε να παράγονται προϊόντα ανταγωνιστικά και προσαρμοσμένα στις απαιτήσεις και ανάγκες των πελατών/ καταναλωτών, τα συστήματα παραγωγής ακολουθώντας την στροφή αυτή προσαρμόζονται ακολουθώντας διαφορετικές οδούς λειτουργίας και δόμησης, ώστε να καταστούν πιο ευέλικτα και προσαρμόσιμα στο νέο αυτό πεδίο. Οι ρομποτικοί βραχίονες, ήδη μέρη των συστημάτων παραγωγής με μεγάλο και διαρκώς αυξανόμενο ρόλο σε αυτά, ήταν εμφανές ότι θα έπρεπε να ακολουθήσουν την νέα αυτή τάση. Ως εκ τούτου αναζητήθηκαν τρόποι για την βελτίωση και αύξηση της προσαρμοστικότητας και ευελιξίας τους όσον αφορά στις εργασίες που θα επιτελούσαν. Η έρευνα στους υπάρχοντες βραχίονες ακολούθησε την οδό της βελτίωσης τους μέσω της βελτίωσης και ανάπτυξης των συστημάτων ελέγχου, των αισθητήρων και της χρήσης τους και την προσθήκη δυνατοτήτων εκμάθησης. Ελάχιστα βήματα πραγματοποιήθηκαν για βελτίωση της δομής τους, με το σκεπτι...
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In this paper the key issues for task based optimal design of metamorphic serial manipulators is presented. The key elements, indices as well methods for solving the optimization problem are presented. Finally, conclusions and future... more
In this paper the key issues for task based optimal design of metamorphic serial manipulators is presented. The key elements, indices as well methods for solving the optimization problem are presented. Finally, conclusions and future research directions are presented.
In this paper the conceptual mechatronic design of an autonomous pseudojoint to be used for structuring serial metamorphic manipulators will be presented. First, the design specifications of the pseudojoint and their mapping to four... more
In this paper the conceptual mechatronic design of an autonomous pseudojoint to be used for structuring serial metamorphic manipulators will be presented. First, the design specifications of the pseudojoint and their mapping to four evaluation criteria is presented. The proposed evaluation method is based on the discrete Choquet integral. Finally, the selection of a novel pseudojoint from four design alternatives is used as a case study of the proposed method.
Metamorphic manipulators are gaining increasing research interest, due the capability of altering their anatomy in order to improve their performance in the execution of a given task. In this paper, an optimization method is presented for... more
Metamorphic manipulators are gaining increasing research interest, due the capability of altering their anatomy in order to improve their performance in the execution of a given task. In this paper, an optimization method is presented for the determination of the best anatomy of a metamorphic manipulator for the execution of a robotic task. The proposed method is applied to a case study 3 DoF metamorphic manipulator. An experimental setup is used for the verification of the results. Measurements of the amperage usage by the manipulator's joint's motors during the execution of the task are used to compare the manipulator's energy usage during task execution for the reference and the derived optimal anatomy.
Research Interests:
The determination of the optimal position of a robotic task within a manipulator’s workspace is crucial for the manipulator to achieve high performance regarding selected aspects of its operation. In this paper, a method for determining... more
The determination of the optimal position of a robotic task within a manipulator’s workspace is crucial for the manipulator to achieve high performance regarding selected aspects of its operation. In this paper, a method for determining the optimal task placement for a serial manipulator is presented, so that the required joint torques are minimized. The task considered comprises the exercise of a given force in a given direction along a 3D path followed by the end effector. Given that many such tasks are usually conducted by human workers and as such the utilized trajectories are quite complex to model, a Human Robot Interaction (HRI) approach was chosen to define the task, where the robot is taught the task trajectory by a human operator. Furthermore, the presented method considers the singular free paths of the manipulator’s end-effector motion in the configuration space. Simulation results are utilized to set up a physical execution of the task in the optimal derived position wi...
In this paper, the inertia characteristics of a 2 Degrees of Freedom (DoF) serial metamorphic manipulator (SMM) structure are investigated. Link mass redistribution is utilized as the dynamic decoupling design approach. The metamorphic... more
In this paper, the inertia characteristics of a 2 Degrees of Freedom (DoF) serial metamorphic manipulator (SMM) structure are investigated. Link mass redistribution is utilized as the dynamic decoupling design approach. The metamorphic structure of the manipulator provides the ability to perform mass redistribution, through the altering of the pseudojoints configuration(anatomy metamorphosis). The overall number of design parameters is reduced and simplicity of the proposed methodology is enhanced. The procedure presented, is executed for a 2 DoF SMM and the advantages of the metamorphic structure, compared with fixed anatomy manipulators, are featured.
Abstract In this paper, a method for evaluating robots as parts of a CPPS based on their abilities is presented. The relationship between the CPPS characteristics and robot abilities is determined. The minimum level of robot abilities is... more
Abstract In this paper, a method for evaluating robots as parts of a CPPS based on their abilities is presented. The relationship between the CPPS characteristics and robot abilities is determined. The minimum level of robot abilities is determined in order to have a positive influence on CPPS. The proposed mapping is used to evaluate the anatomy of three types of open chain robots: fixed anatomy, reconfigurable and metamorphic robots. Metamorphic robots, a class of modular open chain manipulators, are found to be better than the other two types. However, their superiority comes with increased complexity of the system.
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In this paper, a method for the optimal design of metamorphic manipulators is presented, using path dexterity indices in diverse service tasks. The Swedish massage service is chosen as an application, due the very dissimilar techniques... more
In this paper, a method for the optimal design of metamorphic manipulators is presented, using path dexterity indices in diverse service tasks. The Swedish massage service is chosen as an application, due the very dissimilar techniques that can be challenging for fixed anatomy manipulators. These techniques are presented and a mapping to dexterity indices is proposed based on each technique's requirements. A method for the evaluation of metamorphic anatomies over tasks is proposed, and the optimized anatomy of a metamorphic manipulator is determined. Finally, an illustrative example is presented for three tasks, where the advantages of the anatomy optimization are demonstrated.
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This paper presents a method for the task based determination of the suboptimal anatomy of a metamorphic manipulator considering tasks with varying orientation of the end-effector. A performance index representing the orientation... more
This paper presents a method for the task based determination of the suboptimal anatomy of a metamorphic manipulator considering tasks with varying orientation of the end-effector. A performance index representing the orientation dexterity along the rotational motion of the end-effector based on max–min of the rotational manipulability is formulated. In addition, a method based on the screw motion and dual vectors representation is proposed for the determination of the Denavit-Hartemberg (D-H) parameters of each metamorphic link between two successive active joints and the relative homogeneous transformation matrix as a function of the pseudo-joint angles. Thus the dependence of the kinematics of the manipulator and of the performance index on the pseudojoint angles is determined to be used in the searching of the sub-optimal anatomy for the given task, since in metamorphic manipulators each anatomy of a given structure is defined parametrical by the pseudojoint angle values. The proposed approach is tested and demonstrated using a metamorphic manipulator structure with six active joints and four pseudojoints. The rotational velocity performance between the sub-optimal and an arbitrary anatomy is compared and discussed.
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The paper proposes an approach for obtaining optimal positioning of excavators in digging processes. First, constraints and assumptions regarding excavator and dig geometries are stated. The excavator work space is correlated to its... more
The paper proposes an approach for obtaining optimal positioning of excavators in digging processes. First, constraints and assumptions regarding excavator and dig geometries are stated. The excavator work space is correlated to its kinematics and the geometric locus of optimal points – points that correspond to maximal length of boom-arm pair is located. Then the problem of determining the volume of removed soil is analysed and subsequently reduced to the solution of the corresponding 2D problem. Simple mathematical formulas are provided that relate dig and excavator geometries. Finally, simple analytical heuristic functions are used as criteria for locating that optimal point that offers the shortest path to the point of initial location of the excavator.
This paper presents an approach for the optimal design of a reconfigurable robot. The presented method derives the near optimal position of the path to be followed by the end-effector as well as the near optimal anatomy of the... more
This paper presents an approach for the optimal design of a reconfigurable robot. The presented method derives the near optimal position of the path to be followed by the end-effector as well as the near optimal anatomy of the reconfigurable manipulator, namely link lengths, twist angles and offsets, for the given task. The main goal is to maximize the velocity performance of the manipulator along the end effector path of given shape, which is approximated by a generalized Taylor's method, using a cubic interpolation for the position and a Spherical Quadrangle Interpolation (squad) based on quaternions for the determination of the end effector's orientation along the path. The approximate minimum of the Manipulator Velocity Ratio is then computed along the path and used as an objective function to be maximized. Genetic Algorithms are used for the determination of the optimal robot anatomy and the optimal location of the path. 1 INTRODUCTION The last two decades, the robotics...
Modular reconfigurable manipulators are the next step into creating extremely adaptable and flexible industrial robotic systems. Two significant problems of these systems are their lack of homogeneity and the significant amount of down... more
Modular reconfigurable manipulators are the next step into creating extremely adaptable and flexible industrial robotic systems. Two significant problems of these systems are their lack of homogeneity and the significant amount of down time required to perform a physical reconfiguration. In this paper, a new connecting module for modular reconfigurable manipulators in order to limit these problems to a certain degree is presented. The kinematical modeling of the connecting module and a case study showing how it affects the kinematics of a 3 D.O.F. manipulator and its workspace are shown.
In this paper the key issues for task based optimal design of metamorphic serial manipulators is presented. The key elements, indices as well methods for solving the optimization problem are presented. Finally, conclusions and future... more
In this paper the key issues for task based optimal design of metamorphic serial manipulators is presented. The key elements, indices as well methods for solving the optimization problem are presented. Finally, conclusions and future research directions are presented.
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Abstract The modular metamorphic manipulator has been proposed in previous work as a concept of a robotic manipulator, where a single structure could be metamorphosed offline to different anatomies. In this paper, a global kinematic... more
Abstract The modular metamorphic manipulator has been proposed in previous work as a concept of a robotic manipulator, where a single structure could be metamorphosed offline to different anatomies. In this paper, a global kinematic measure for the evaluation of the emerging anatomies, of a given structure of a class of 3 d.o.f. modular metamorphic manipulators is introduced. The proposed high performance area (HPA) measure depicts the dexterous workspace defined by a chosen threshold of a local kinematic index to meet the specifications of the given task. The region of the anatomy's workspace, where the selected local kinematic index meets the specifications is cross-sectioned by the XZ-plane in C-space, and the maximum area formed is the HPA. In order to reduce the computational burden, a procedure is proposed to approximate the HPA. The HPA is used to formulate an optimization problem for the determination of the optimal anatomy of a given metamorphic structure, which is solved using a genetic algorithm. A case study application of a 3 d.o.f. metamorphic structure is presented, using the manipulability measure and the conditioning index as local indices. The presented results are thoroughly discussed and the paper concludes with some hints for future work.
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ABSTRACT On this paper, the objective is to introduce an optimization algorithm in order to determine the near optimal location of a path following task for a 6 non redundant manipulator, so that its end-effector can follow a given 3D... more
ABSTRACT On this paper, the objective is to introduce an optimization algorithm in order to determine the near optimal location of a path following task for a 6 non redundant manipulator, so that its end-effector can follow a given 3D curve and orientation, taking into account the maximization of the robot velocity performance. The optimization is conducted using as an objective function the minimum value of the Manipulator Velocity Ratio (MVR) along the path, producing the largest possible end-effector velocity while maintaining minimum joint speed values. The optimization of the objective function is based on Genetic Algorithms. The minimum of the MVR is determined by a technique which approximates the given path using cubic interpolation for the position and squad interpolation based on quaternions for the orientation. A large number of experiments show the effectiveness of the proposed approach and the most indicative of the results are presented and discussed at the end of the paper.
Research Interests:
One of the most important tasks of the network of excellence INNOVATIVE PRODUCTION MACHINES AND SYSTEMS (NoE I*PROMS, www.iproms.org) is the joint collaborative review and evaluation of research trends in manufacturing and the respective... more
One of the most important tasks of the network of excellence INNOVATIVE PRODUCTION MACHINES AND SYSTEMS (NoE I*PROMS, www.iproms.org) is the joint collaborative review and evaluation of research trends in manufacturing and the respective update of research roadmaps for industry and public research. This contribution presents an overview and the first results from a Delphi study conducted in this framework displaying the importance of actual and future research topics in manufacturing.
Research Interests:
Designing a reconfigurable manufacturing robotic workcell is a complex and resource demanding procedure. In this work a multi criteria index is introduced, allowing the designer to evaluate the various anatomies achieved by a... more
Designing a reconfigurable manufacturing robotic workcell is a complex and resource demanding procedure. In this work a multi criteria index is introduced, allowing the designer to evaluate the various anatomies achieved by a reconfigurable manipulator, and to define the area in the manipulator’s configuration space where a task can be accomplished with good performance under the selected performance measure. An adaptive neuro-fuzzy inference system is trained, in order to rapidly produce the index value for arbitrary anatomies achieved by the manipulator. The system is tested using a case study reconfigurable manipulator, and the derived results determined by the system after its training are presented and compared to the actual index value for calculated for the relevant anatomy.
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ABSTRACT a b s t r a c t This paper introduces an approach for the determination of the best anatomy of a metamorphic manipulator for a given task at a given location. The location of the task is determined by maximizing the performance... more
ABSTRACT a b s t r a c t This paper introduces an approach for the determination of the best anatomy of a metamorphic manipulator for a given task at a given location. The location of the task is determined by maximizing the performance of a current industrial fixed anatomy robot. Two types of tasks are considered: a point to point task and a path following task, where in the first case the approximated minimum of the manipulability index is formed along the task points and in the second case the approximated minimum of the manipulator velocity ratio is formed along the line segments. These indexes are maximized in order to determine the best anatomy for the task. The proposed approach is tested and the results show that the determined best anatomy for each type of task acquired higher performance than the respective one achieved by the fixed anatomy manipulator.