The paper tries to outline the state of the art in space robotics. It discusses the technologies used in ROTEX, the first remotely controlled space robot which flew with the shuttle Columbia in April 1993, but it also...
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The paper tries to outline the state of the art in space robotics. It discusses the technologies used in ROTEX, the first remotely controlled space robot which flew with the shuttle Columbia in April 1993, but it also gives a review of the major space robot projects envisioned by different nations for the next decade. The mechatronics and dynamics aspects of space robots including free-flying systems are briefly discussed. Broader attention is given to the telerobotic and teleoperational control loop structures, including predictive delay-compensating graphics simulation. The paper finally tries to emphasize that by task-level programming (involving 'learning by showing' on a high level) future space robots will be powerful tools for scientists and ground operators which are not robot specialists. The tele-sensor programming concept of ROTEX was a first step in this direction. We plead for flying a variety of space robot systems in the near future in order to enhance experience with and confidence in these technologies as quickly as possible.
作者：
Varga, ADLR-Oberpfaffenhofen
Institute for Robotics and System Dynamics German Aerospace Research Establishment (DLR) Wessling Germany
A new algorithm is proposed for the pole assignment of single-input linear time-invariant systems, The proposed algorithm belongs to the family of Hessenberg methods and is based on an implicit multishift QR-like tech...
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A new algorithm is proposed for the pole assignment of single-input linear time-invariant systems, The proposed algorithm belongs to the family of Hessenberg methods and is based on an implicit multishift QR-like technique, The new method compares favorably in many respects (speed, memory usage) with existing numerically stable methods, Its improved vectorizability guarantees good opportunities for parallel implementation on high-performance computers.
作者：
王龙J. AckermannRobust Control Group
Institute of Robotics and System Dynamics German Aerospace Research CenterD-82230 Wessling Germany)
Presented are the fact that the transfer function from the front steering angle to yaw rate is strictly positive real, irrespective of the uncertain mass and uncertain velocity, how to determine the positivity margin ...
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Presented are the fact that the transfer function from the front steering angle to yaw rate is strictly positive real, irrespective of the uncertain mass and uncertain velocity, how to determine the positivity margin for this transfer function (some stabilization results are obtained), and how to check the positivity of a controller family. Furthermore,by exploiting the intrinsic structure of system equations and uncertainties, a nonconservative PID stabilization criterion for driver support systems is established. Some interesting results on positivity and connections of PID controllers are shown. Finally, some extreme point results on PID α-stabilization are obtained. These results give certain explanations and justifications for the simulation results performed at German Aerospace Research Center.
作者：
Varga, A.
Institute for Robotics and System Dynamics Oberpfaffenhofen Wessling82230 Germany
The reduction of the state-matrix of a linear time-invariant state-space model to a block-diagonal form by using a state coordinate transformation is equivalent with an additive decomposition of the corresponding tran...
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We propose numerically reliable state-space algorithms for computing several coprime factorizations of rational matrices: (1) factorizations with factors having poles in a given stability domain;(2) factorizations wit...
We propose numerically reliable state-space algorithms for computing several coprime factorizations of rational matrices: (1) factorizations with factors having poles in a given stability domain;(2) factorizations with proper stable factors;(3) factorizations with inner and J-inner denominators. The new algorithms are based on a recursive generalized Schur algorithm for pole dislocation. They are generally applicable whether the underlying descriptor state-space representation is minimal or not, and whether it is stabilizable/detectable or not. The proposed algorithms are useful in solving various computational problems for both standard and descriptor system representations. (C) 1998 Elsevier Science Inc.
In this paper we describe an autonomous laparoscopic guidance system for laparoscopic surgery. By analyzing the color histogram of typical laparoscopic images, we propose to code the instrument by a color that does no...
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ISBN:
(纸本)3540627340
In this paper we describe an autonomous laparoscopic guidance system for laparoscopic surgery. By analyzing the color histogram of typical laparoscopic images, we propose to code the instrument by a color that does not appear. In terms of image processing, we segment the color mark in the visual image and use the location information to control a robot such that the tip of the color-coded surgical instrument are continuously shown in the central area of the monitor device and a constant distance is held in the case of stereo. The system is implemented by using an image processing hardware and a robot which are all commercially available. Clinical tests show the robustness and efficacy of the system.
For real-time, hardware-in-the-loop simulations an industrial robot is used in order to represent the motion of the software simulated end-effector trajectory of space manipulators. To reduce the modelling complexity,...
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作者：
Varga, ADLR–Oberpfaffenhofen
German Aerospace Research Establishment Institute for Robotics and System Dynamics Wessling D-82230 P.O.B. 1116 Germany
The discrete-time periodic Lyapunov equation has several important applications in the analysis and design of linear periodic control systems. Specific applications considered are the solution of state- and output-fee...
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The discrete-time periodic Lyapunov equation has several important applications in the analysis and design of linear periodic control systems. Specific applications considered are the solution of state- and output-feedback optimal periodic control problems, the stabilization by periodic state feedback and the square-root balancing of discrete-time periodic systems. Efficient and numerically reliable algorithms based on the periodic Schur decomposition are proposed for the solution of periodic Lyapunov equations. The proposed algorithms are extensions of the direct solution methods for standard discrete-time Lyapunov equations for the case of indefinite as well as non-negative definite solution.
作者：
Kaesbauer, D.Ackermann, J.
Oberpfaffenhofen Institute of Robotics and System Dynamics D 82234 Wessling Germany
The inverted pendulum is used as an example to illustrate controller fragility under minimum norm state feedback. The stabilization process gets trapped in a cusp. A parameter space representation shows a safe escape....
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The inverted pendulum is used as an example to illustrate controller fragility under minimum norm state feedback. The stabilization process gets trapped in a cusp. A parameter space representation shows a safe escape....
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