This paper presents some remarks on PD control in joint space for serial manipulators whose dynamics is expressed in terms of two different kind of quasi-velocities. Robot dynamics algorithms in terms of so called nor...
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This paper presents some remarks on PD control in joint space for serial manipulators whose dynamics is expressed in terms of two different kind of quasi-velocities. Robot dynamics algorithms in terms of so called normalized quasi- velocities are recursive in nature and consists of two recursions: one starts from a base of the manipulator towards its tip and the second in opposite direction. Both recursions are described by making use of vector-matrix notation. In the second work authors introduce an instantaneous eigenstructure quasi-velocity formulation as a result of numerical mass matrix factorization. Both PD controls were tested on a model of manipulator with two degrees of freedom. In this paper we adopt standard PD control known in robotic literature to a case when robot dynamics is formulated in terms of quasi-velocities.
An application of a special approach aiming at the development of a new branch of soft computing (SC) for the adaptive control of approximately and partially known electromechanical systems is reported. Like "tra...
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An application of a special approach aiming at the development of a new branch of soft computing (SC) for the adaptive control of approximately and partially known electromechanical systems is reported. Like "traditional" SC it uses "uniform structures" for modeling, but these structures are obtained from the symplectic group (SG). This approach can considerably reduce the number of free parameters in the model in comparison e.g. with that of the neural networks or ample sets of fuzzy rules. It also replaces the process of parameter tuning with simple, lucid, and explicit algebraic operations of limited steps. While in the previous approaches SG was utilized as an inner symmetry of classical mechanical systems, in the present one it is used in a formal way not utilizing mechanical symmetries. Furthermore, SG is not the internal symmetry of electrical, that is of electro-mechanical systems. In the present paper the new formal approach is demonstrated in the adaptive control of a 3 mechanical DOF SCARA-type robot arm actuated by DC motors together forming a 6 DOF electromechanical system. It is concluded on the basis of simulations that the control designed for the 3 DOF mechanical degrees of freedom can efficiently compensate for the behavior of the electrical degrees of freedom not modeled by the controller.
This paper presents a comparison of controls for manipulators whose dynamics is expressed in terms of quasi-velocities. Robot dynamic algorithms in terms of quasi-velocities are recursive in nature and consists of two...
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This paper presents a comparison of controls for manipulators whose dynamics is expressed in terms of quasi-velocities. Robot dynamic algorithms in terms of quasi-velocities are recursive in nature and consists of two recursions: one starts from a base of the manipulator towards its tip and the second in opposite direction. Both recursions are described by using vector-matrix notation. Quasi-velocities are a result of numerical mass matrix factorization. They were tested on a model of manipulator with two degrees of freedom. In this paper we adopt standard control algorithms known in robotic literature to a case when robot dynamics is formulated in terms of quasi-velocities.
Traditional fuzzy controllers or artificial neural networks are constrained by standardized formal procedures and structural restrictions. While in general it is guaranteed that these approaches or their integration c...
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Traditional fuzzy controllers or artificial neural networks are constrained by standardized formal procedures and structural restrictions. While in general it is guaranteed that these approaches or their integration can solve a quite wide class of problems, their "orthodox" application may result in too complicated control not exploiting the peculiarities of the given task under consideration. The aim of the paper is to demonstrate that unconventional integration of simple elements such as classic PID/ST, regression analysis, saturated sigmoid transition functions, fuzzy sets and uniform structures obtained from the Lagrangian classical mechanics instead of the connection structure of a feedforward artificial neural networks can result in a simple and efficient adaptive control for robots involved in unknown environmental dynamic interaction. Due to their simplicity and reduced number of parameters real time tuning can be carried out in these structures. Most of the parameters are independent of the particular problem to be solved and neither "scaling problems" nor "network paralysis" occur during the learning phase. It is concluded that the different components of the control can successfully co-operate in finding the "proper" system model even in the case of very rough initial model estimation and external interaction.
This paper presents a new control algorithm for manipulators whose dynamics is expressed in terms of quasi-velocities. In contrary to our previous algorithms (1995) this one also considers gravitational forces. Robot ...
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This paper presents a new control algorithm for manipulators whose dynamics is expressed in terms of quasi-velocities. In contrary to our previous algorithms (1995) this one also considers gravitational forces. Robot dynamic algorithms in terms of quasi-velocities are recursive in nature and consists of two recursions: one starts from a base of the manipulator towards its tip and the other in opposite direction. Both recursions are described by using vector-matrix notation. The algorithm presented makes the system stable in the sense of Lyapunov. The algorithm was tested on the model of a manipulator with two degrees of freedom.
This paper considers the control scheme for manipulators with elastic joints. The proposed algorithm requires only position signal measurements. This algorithm is an extension of the control algorithm proposed by Lori...
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This paper considers the control scheme for manipulators with elastic joints. The proposed algorithm requires only position signal measurements. This algorithm is an extension of the control algorithm proposed by Loria and Ortega (1995). We have developed for the proposed model of manipulator an adaptive version of the control algorithm, based on the Lyapunov stability theory. This algorithm ensures that the position regulation error or tracking error possess desirable convergence property: semiglobal convergence to an arbitrarily small neighbourhood of zero in the presence of bounded disturbance. This paper considers three theorems, which were used to prove that this algorithm is semiglobal stable. New adaptive control algorithms which require only link position measurements, have been developed and tested, both on PC computer and on an experimental set-up.
Presents an approach to sensor-based obstacle modeling in a configuration space for manipulator motion planning in unknown environments. In order to achieve this objective, an efficient algorithm is used to fast map o...
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Presents an approach to sensor-based obstacle modeling in a configuration space for manipulator motion planning in unknown environments. In order to achieve this objective, an efficient algorithm is used to fast map obstacles based on defined fundamental obstacles in the workspace and their images in the configuration space. A robotic manipulator is assumed to be equipped with distance sensors to detect obstacles in the local region. By computation of the critical points of an obstacle based on information acquired by the distance sensors, an obstacle model in the configuration space is constructed. By using this sensor-based configuration space modeling, robot motion planning in unknown environments can be performed in realistic time frames.
This paper is a brief report on the recent improvement of a novel approach for the control of approximately and partially known multivariable, nonlinear, strongly coupled mechanical systems under dynamic interaction w...
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This paper is a brief report on the recent improvement of a novel approach for the control of approximately and partially known multivariable, nonlinear, strongly coupled mechanical systems under dynamic interaction with an unmodeled environment. This method uses simple uniform structures and standard procedures. In contrast to the traditional approaches, instead of Kolmogorov's approximation theorem, these special structures originate from the mathematical framework of the Lagrangian mechanics. This results in a considerable reduction of modeling complexity since the number of the tunable parameters can be derived by knowing only the degree of freedom of the system to be controlled. This fact simplifies parameter tuning or "learning". Further advantage is that the great majority of "scaling" problems can be avoided in the case of the structures used here. The operation of the method is illustrated by simulation results developed for a 3 degree-of-freedom SCARA robot.
We present new control algorithms for robots whose dynamics are described in terms of quasi-velocities. We incorporate into the forward dynamics algorithms the new control laws in terms of normalized and unnormalized ...
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We present new control algorithms for robots whose dynamics are described in terms of quasi-velocities. We incorporate into the forward dynamics algorithms the new control laws in terms of normalized and unnormalized quasi-velocities. We consider two cases: end point trajectory tracking and trajectory tracking algorithms. It is shown that by proper choosing of the Lyapunov function candidate a dynamic system with appropriate feedback is asymptotically and exponentially stable and follows a desired trajectory in the task space. The control laws track the desired position, velocity, and acceleration in Cartesian space. All control laws have new architecture in the sense that they are derived in the so called quasi-velocity and quasi-force space. We also propose a sliding mode control in quasi-velocity and quasi-force spaces.
In this paper, a simple one degree of freedom robot, designed for both research and leaching purposes, is described. An experimental set-up consists of DC-motor, a rate generator, a harmonic drive, a control system, a...
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ISBN:
(纸本)0780336135
In this paper, a simple one degree of freedom robot, designed for both research and leaching purposes, is described. An experimental set-up consists of DC-motor, a rate generator, a harmonic drive, a control system, and load. A system has an open architecture and allows the programmer to distribute the intelligence between the single board computer (SBC) and PC compatible computer, which are connected through interface, The SEC collects data from different sensors. System software resides on SEC and PC compatible computer. A PD controller has been designed and successfully implemented. Different new adaptive control algorithms, which require only link position measurements, were developed and lt sled, both on SUN workstation and on the experimental set-up.
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