313 research outputs found
Cooperative Control of the Dual Gantry-Tau Robot
Utilization of multiple parallel robots operating in the same work place and cooperating
on the same job have opened up new challenges in coordination control strategies.
Multiple robot control is a natural progression for Parallel Kinematic Machines (PKM) as
it offers many of the desirable qualities especially in cooperative arrangements where
multiple robots can be associated with an easily reconfigurable parallel machine. These
special characteristics allow much faster and precise manipulations especially in
manufacturing industries. With the possibility of cooperative control architecture, PKMs
will be able to perform many of the tasks currently requiring dual serial robots such as
complex assemblies, heavy load sharing and large machining jobs
INTELLIGENT CONTROLLING THE GRIPPING FORCE OF AN OBJECT BY TWO COMPUTER-CONTROLLED COOPERATIVE ROBOTS
This paper presents a Multiple Adaptive Neuro-Fuzzy Inference System (MANFIS)-based method for regulating the handling force of a common object. The foundation of this method is the prediction of the inverse dynamics of a cooperative robotic system made up of two 3-DOF robotic manipulators. Considering the no slip in contact between the tool and the object, an object is moved. to create and feed the MANFIS database, the inverse kinematics and dynamic equations of motion for the closed chain of motion for both arms are established in Matlab. Results from a SimMechanic simulation are given to demonstrate how well the suggested ANFIS controller works. Several manipulated object movements covering the shared workspace of the two manipulator arms are used to test the proposed control strategy
Subspace-based Identification of a Parallel Kinematic Manipulator Dynamics
This thesis deals with the identification of the dynamics of a Parallel Kinematic Manipulator, namely the Gantry-Tau patented by ABB located in the Robotics lav at LTH, Lund. The approach considered for modelling is subspace-based identification of linear models, where measurements from the robot motion are used to estimate the unknown parameters in the models. Rigid body dynamics and flexible body dynamics are taken into account and a description of the system in terms of a network with spring-damper pairs at the edges, representing the clusters, and masses at the nodes representing the end-effector and the carts, is proposed
Kinematic calibration of Orthoglide-type mechanisms from observation of parallel leg motions
The paper proposes a new calibration method for parallel manipulators that
allows efficient identification of the joint offsets using observations of the
manipulator leg parallelism with respect to the base surface. The method
employs a simple and low-cost measuring system, which evaluates deviation of
the leg location during motions that are assumed to preserve the leg
parallelism for the nominal values of the manipulator parameters. Using the
measured deviations, the developed algorithm estimates the joint offsets that
are treated as the most essential parameters to be identified. The validity of
the proposed calibration method and efficiency of the developed numerical
algorithms are confirmed by experimental results. The sensitivity of the
measurement methods and the calibration accuracy are also studied
CAD-based approach for identification of elasto-static parameters of robotic manipulators
The paper presents an approach for the identification of elasto-static
parameters of a robotic manipulator using the virtual experiments in a CAD
environment. It is based on the numerical processing of the data extracted from
the finite element analysis results, which are obtained for isolated
manipulator links. This approach allows to obtain the desired stiffness
matrices taking into account the complex shape of the links, couplings between
rotational/translational deflections and particularities of the joints
connecting adjacent links. These matrices are integral parts of the manipulator
lumped stiffness model that are widely used in robotics due to its high
computational efficiency. To improve the identification accuracy,
recommendations for optimal settings of the virtual experiments are given, as
well as relevant statistical processing techniques are proposed. Efficiency of
the developed approach is confirmed by a simulation study that shows that the
accuracy in evaluating the stiffness matrix elements is about 0.1%.Comment: arXiv admin note: substantial text overlap with arXiv:0909.146
Modeling and Balancing of Spherical Pendulum using a Parallel Kinematic Manipulator
The balancing act of an inverted pendulum with a robotic manipulator is a classical benchmark for testing modern control strategies in conjunction with fast sensor-guided movements. From the control design perspective, it presents a challenging and difficult problem as the system is open-loop unstable and includes nonlinear effects in the actuators, such as friction, backlash, and elasticity. In addition, the necessity of a sensor system that can measure the inclination angles of the pendulum contributes to the complexity of the balancing problem. The pendulum is projected onto the xz and yz planes of the inertial coordinate system. These projections are controlled by a state-space controller. A specially developed sensor system allows the contactless measurement of the inclination angles of the pendulum. This system consists of a small magnet, placed at the bottom of the pendulum and Hall-effect sensors placed below the end effector
Gantry tĂpusĂş, párhuzamos hajtásĂş robot modellezĂ©se Ă©s vizsgálata
Az iparban folyamatosan növekszik az igĂ©ny a pontosabb Ă©s gyorsabb tevĂ©kenysĂ©gek iránt. ĂŤgy a robotok használata sem kivĂ©tel, Ă©s világviszonylatban folyik a kutatás olyan párhuzamos struktĂşrájĂş robotok fejlesztĂ©sĂ©re, melyek a megnövekedett Ă©s homogĂ©n munkateret cĂ©lozzák meg. Jelen dolgozat egy olyan portáldaru tĂpusĂş robotot mutat be, mely felĂ©pĂtĂ©sĂ©bĹ‘l adĂłdĂłan többszörösen is megfelel az elĹ‘bbi feltĂ©teleknek. Ezen elĹ‘nyök a robot geometriai, kinematikai Ă©s dinamikai modellalkotására alapozva lettek megállapĂtva
Outils pour l’identification des paramètres de raideur des robots à l’aide d’un logiciel de CAO
This report proposes a CAD-based approach for identification of the elasto-static parameters of the robotic manipulators. The main contributions are in the areas of virtual experiment planning and algorithmic data processing, which allows to obtain the stiffness matrix with required accuracy. In contrast to previous works, the developed technique operates with the deflection field produced by virtual experiments in a CAD environment. The proposed approach provides high identification accuracy (about 0.1% for the stiffness matrix element) and is able to take into account the real shape of the link, coupling between rotational/translational deflections and joint particularities. To compute the stiffness matrix, the numerical technique has been developed, and some recommendations for optimal settings of the virtual experiments are given. In order to minimize the identification errors, the statistical data processing technique was applied. The advantages of the developed approach have been confirmed by case studies dealing with the links of parallel manipulator of the Orthoglide family, for which the identification errors have been reduced to 0.1%ANR COROUSS
Design Tool for Kinematics of Multibody Systems
This research provides a methodology and a tool for selection of appropriate robotic system based on the singularities in the workspace of the machines, suitable for both, designers and users. The kinematic problem solutions are managed through design methodology and represented with function modelling language, IDEF0. This novel approach specifies step by step activities on how to model robotic systems with math and programming tools, like Maple 17 and Matlab 2010. Symbolical and numerical solutions of kinematics, Jacobian matrix, singularities and workspace are successfully obtained for three types of multibody systems; general CNC machine, Mitsubishi MELFA RV-3SDB robot and Yaskawa Motoman DA-20, dual arm collaborative robot. CNC-R Global Reconfigurable Kinematic Model is developed for analyses of different types of manipulators. The main purpose of this design tool for kinematics of multibody systems is to help in kinematics problem solving, by providing visual representation of the workspace with the singularity locus of the same. It represents a set of iterative methods for kinematic design of manipulators, and so at the end, visual presentation of the effective work region, including singular configurations. The methodology is appropriate for any n-DOF multibody system, even for dual arm collaborativ
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