This paper makes use of a matched-filterbank (MAFI) approach to study the forward-only and forward-backward Capon (termed FCapon and FBCapon, respectively) as well as the forward-only and forward-backward APES (FAPES ...
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This paper makes use of a matched-filterbank (MAFI) approach to study the forward-only and forward-backward Capon (termed FCapon and FBCapon, respectively) as well as the forward-only and forward-backward APES (FAPES and FBAPES, respectively) estimators for complex spectral estimation. In particular, we prove that, to within a second-order approximation: (a) FCapon and FBCapon are both biased downward; (b) the bias of FBCapon is half that of FCapon; and (c) FAPES and FBAPES are both unbiased. We also show that computationally the APES estimators are only slightly more involved than the Capon (1969) estimators. A natural and logical conclusion of this paper follows as the preference of APES over the Capon estimators in most applications. Numerical examples are also presented to demonstrate quantitatively the properties of the estimators under study.
A grey box model-based method for fault diagnosis is proposed in this paper which is based on a first principle model of the process unit: a heat exchanger, and on a grey box model of the fault: the deterioration of t...
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A grey box model-based method for fault diagnosis is proposed in this paper which is based on a first principle model of the process unit: a heat exchanger, and on a grey box model of the fault: the deterioration of the heat transfer surface by aging. Under normal operating conditions the heat transfer coefficient is constant or slowly decreasing due to a layer of settled material building up on the heat transfer surface, and we propose to use a recursive least squares estimator with forgetting factor to track the heat transfer coefficients during these stages. In old heat exchangers, big chunks of the settled material can break away from the surface causing the heat transfer coefficients to rise sharply. This fault is detected via detection of abrupt positive jump in the estimated heat transfer coefficients using a Hinkley detector
The generation of rule-bases in conventional fuzzy logic controllers can be a difficult and time consuming problem for implementation by process operators thus affecting their wider applicability. A Self-Learning Fuzz...
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The generation of rule-bases in conventional fuzzy logic controllers can be a difficult and time consuming problem for implementation by process operators thus affecting their wider applicability. A Self-Learning Fuzzy Logic control (SLFLC) offers a possible solution. A performance study is therefore presented to evaluate the performance of a proposed SLFLC by analysing its transient performance for a variety of on-line tests and examining its ability to generate a consistent set of rules, based on a predetermined criteria. The results presented show that even with a limited knowledge of the process, the self-learning procedure is able to develop a suitable set of rules and produce a satisfactory process performance with some degree of robustness and repeatability when applied to a non-linear single-input single-output (SISO) or multi-input multi-output (MIMO) laboratory liquid-level processes.
Trajectory control for a reusable launch vehicle (RLV) is considered in the reentry and launch modes. Decoupling sliding mode controllers are designed to achieve the asymptotic tracking of Euler angles' profiles u...
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Trajectory control for a reusable launch vehicle (RLV) is considered in the reentry and launch modes. Decoupling sliding mode controllers are designed to achieve the asymptotic tracking of Euler angles' profiles upon plant uncertainties and external disturbances. Effectiveness of the sliding mode controllers is confirmed by simulations of trajectory tracking in a trimmed condition for the WB001 RLV studied at NASA Marshall Space Flight Center.
Two major improvements, controlled fan-in and automated initial-circuit production, were made over the random generator of benchmark circuits presented at DAC'94. This is an important progress towards our goal of ...
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Two major improvements, controlled fan-in and automated initial-circuit production, were made over the random generator of benchmark circuits presented at DAC'94. This is an important progress towards our goal of random benchmarking: more general and secure testing, increasing the naturality of random circuits by controlling their attributes, and obtaining test results by which the difference of performances under evaluation can be made clear.
Trajectory control for a reusable launch vehicle (RLV) is considered for two operational modes: reentry and launch modes are considered. Decentralized sliding mode controllers are designed to achieve the de-coupled as...
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Trajectory control for a reusable launch vehicle (RLV) is considered for two operational modes: reentry and launch modes are considered. Decentralized sliding mode controllers are designed to achieve the de-coupled asymptotic tracking of Euler angles' profiles upon plant uncertainties and external disturbances. Two sliding mode control strategies are investigated: direct Euler angles' profiles tracking and angular rates tracking in combination with a coordinated turn inversion. Effectiveness of the sliding mode controllers is confirmed by simulations of a trajectory tracking for the WB001 RLV studied at NASA Marshall Space Flight Center.
For the well known ball-and-beam system, we design a new saturation control law, which employs state-dependent saturation levels and guarantees global asymptotic stability, not achieved with previous designs.
For the well known ball-and-beam system, we design a new saturation control law, which employs state-dependent saturation levels and guarantees global asymptotic stability, not achieved with previous designs.
The passivity property of dissipative mechanical structures has long been exploited in designing passive controllers that provide robust stability even in the presence of unmodeled dynamics of the system. For an input...
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The passivity property of dissipative mechanical structures has long been exploited in designing passive controllers that provide robust stability even in the presence of unmodeled dynamics of the system. For an input/output map of a flexible structure to be passive, collocation of the actuators and sensors is required and also the sensors should measure the velocity of the system. The so-called smart structures frequently have more sensors than actuators. Therefore, the passive controller can at best utilize only a subset of the sensors. In this paper we consider the design of a squaring down matrix which would render a system passive subject to some additional performance considerations. The problem of obtaining the synthesized passive output is cast as a set of linear matrix inequalities (LMIs) which can be efficiently solved by the LMI Toolbox in Matlab. We apply this procedure with the assumption that the sensors provide both displacement and velocity information which is generally not true. We show that the passive controllers can be implemented without the use of velocity information. By using synthesized passive outputs in addition to naturally occurring passive outputs, we obtain better system performance. We present experimental results involving a single flexible beam with torque input and hub angular position and strain gage outputs.
This paper presents a PD controller for robot manipulators simultaneously considering joint flexibility, actuators dynamics as well as friction. The convergence analysis of the proposed PD controller is carried out us...
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This paper presents a PD controller for robot manipulators simultaneously considering joint flexibility, actuators dynamics as well as friction. The convergence analysis of the proposed PD controller is carried out using passivity. Global convergence to a desired fixed angular position is proved only using position and velocity measurements.
Two major improvements, controlled fan-in and automated initial-circuit production, were made over the random generator of benchmark circuits presented at DAC'94. This is an important progress towards our goal of ...
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ISBN:
(纸本)9780818677861
Two major improvements, controlled fan-in and automated initial-circuit production, were made over the random generator of benchmark circuits presented at DAC'94. This is an important progress towards our goal of random benchmarking: more general and secure testing, increasing the naturality of random circuits by controlling their attributes, and obtaining test results by which the difference of performances under evaluation can be made clear.
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