A fundamental limitation in achieving high performance control for multivariable plants is associated with the operating range of the control input signals associated with the plant, i.e. in order to design realistic ...
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A fundamental limitation in achieving high performance control for multivariable plants is associated with the operating range of the control input signals associated with the plant, i.e. in order to design realistic controllers for a plant, it is essential to take into account control signal saturation effects. This paper describes various classes of controllers for a LTI plant, which have the property that they solve the robust, servomechanism problem for constant tracking/disturbance signals, and maximize the operating range of the controllers for the plant . Some application studies re the control of a distillation column with pressure variation are included to illustrate the behaviour of the controllers.
作者：
R.G. BonitzT.C. HsiaSystems
Control and Robotics Laboratory Department of Electrical and Computer Engineering University of California Los Angeles Davis CA USA
An internal force-based impedance control scheme for two coordinating robots manipulating a rigid object via palm grasping is introduced. The minimal internal force required to maintain the grasp on the object is comp...
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An internal force-based impedance control scheme for two coordinating robots manipulating a rigid object via palm grasping is introduced. The minimal internal force required to maintain the grasp on the object is computed from the frictional constraints and sensed forces. A closed-form solution to the minimization problem is developed which makes the algorithm suitable for real-time control. The controller uses sensed moments at the palm interface to maintain proper orientation of the palms to achieve maximum surface contact. Each manipulator's nonlinear dynamics is compensated by a robust auxiliary controller which is insensitive to robot-model uncertainty and payload variation. The controller is only weakly-dependent on each manipulator's inertia matrix. Stability of the system is analyzed. Rigorous experimental investigations are are performed and the results presented which validate the proposed concepts.
We consider a special discrete-time hybrid problem: the plant state "lives" in IRn and is affected by real-valued norm-bounded disturbances;the control input and measurement signals are sequences of symbols....
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This paper presents an investigation into tne nature ot control algorithms in relation to that of the architectures for real-time applications so that a close match be forged between them. Several algorithms of regula...
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This paper presents an investigation into tne nature ot control algorithms in relation to that of the architectures for real-time applications so that a close match be forged between them. Several algorithms of regular and irregular nature are implemented on a number of architectures possessing different features. Partitioning and mapping of the algorithms, algorithm regularity and hardware and algorithm granularity are addressed in implementing the algorithms on parallel architectures. A comparison of the results of implementations is made to establish merits of the development of parallel architectures for real-time applications. Finally, the potential of heterogeneous architectures in real-time applications has been justified by the development of a three-node architecture and its performance verification in comparison to uni-processor and two-node homogeneous and heterogeneous architectures.
In analyzing the behavior of refinery heaters, it turns out that the process dynamics is slow and can be cast into the form of input-output discrete-time controlled autoregressive and integrated moving-average (CARIMA...
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In analyzing the behavior of refinery heaters, it turns out that the process dynamics is slow and can be cast into the form of input-output discrete-time controlled autoregressive and integrated moving-average (CARIMA) model with large time-lag which poses difficulties in control design. To overcome these difficulties, modified Diophantine equations are introduced in this paper to facilitate the development of filtered outlet temperature predictions so that the closed-loop system (the refinery heater model with a recursive predictive controller) have desired stability properties. Simulation studies on a pilot-scale process heaters have illustrated the flexibility and computational effectiveness of the developed predictive control algorithm.
This paper presents significant new results on the stability and convergence properties of a general class of iterative learning control schemes derived using two-dimensional(2D) systems theory. These results apply fo...
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This paper presents significant new results on the stability and convergence properties of a general class of iterative learning control schemes derived using two-dimensional(2D) systems theory. These results apply for a general learning law which (explicitly) uses information from previous iterations or trials. A key feature of these results is that they are expressed in terms of standard linear systems theoretic properties, such as relative degree and the location of the zeros.
Repetitive, or multipass, processes are uniquely characterized by a series of sweeps, or passes through a set of dynamics defined over the so-called pass length which is finite and constant. The unique systems theoret...
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Repetitive, or multipass, processes are uniquely characterized by a series of sweeps, or passes through a set of dynamics defined over the so-called pass length which is finite and constant. The unique systems theoretic/control problem is that the sequence of outputs, or pass profiles, can contain oscillations which increase in amplitutde in the pass to pass direction. These processes can be modelled as a class of quarter plane causal 2D linear systems and this paper shows that the boundary (or pass initial) conditions alone can destabilize them. Hence they must be 'adequately modelled' in a given application and it is the boundary conditions which essentially distinguish the dynamic behaviour of linear repetitive processes from other classes of 2D linear systems.
In order to improve the resolution of spectrum analysis, the traditional method is to take more sampling periods, e. g. 50 sampling periods corresponding to the spectrum interval of I Hz. This method is not suitable t...
In order to improve the resolution of spectrum analysis, the traditional method is to take more sampling periods, e. g. 50 sampling periods corresponding to the spectrum interval of I Hz. This method is not suitable to the interharmonic measurement, because most interharmonics vary rather quickly with the time and so the analysis results based on long time sampling may be useless. In this paper the zero-padding technique with short sampling time is used to resolve interharmonics, and the zoom FFT is used to decrease the computation time in order to meet the needs of real-time measurement. The simulating computation shows that the resolution for two adjacent frequency components is usually sufficient to measure harmonics and interharmonics in power systems with acceptable short sampling and computation time. This method is also suited to analyse harmonics and interharmonics when there exists an undesirable asynchronous deviation between the sampling period and the signal period.
Many problems in nonlinear control theory (like, for instance, feedback linearization problem) leed to examination of integrability of a Pfaffian system. In a generic case a Pfaffian system is not integrable. Therefor...
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Many problems in nonlinear control theory (like, for instance, feedback linearization problem) leed to examination of integrability of a Pfaffian system. In a generic case a Pfaffian system is not integrable. Therefore, how to approximate non-integrable Pfafian systems by integrable ones and how this approximation can applied in practice appears to be a natural and important problem. In the present paper we establish some measures of non-integrability of Pfaffian system of arbitrary dimension and discuss their relation to approximations of non-integrable Pfaffian systems by integrable ones. Our work is motivated by expected applications to approximate feedback linearization of multi-input nonlinear systems.
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