摘要:

AbstractWe study the Godard/CMA error surface in adapting the impulse response coefficients of a finite‐length, tapped‐delay‐line filter to equalize a white, zero‐mean, binary (± 1) source that suffers ISI due to a linear channel. Our results arise primarily from examination of the expressions for the gradient and the Hessian in the baud‐spaced equalizer parameter space of the cost‐function in this particular setting. This paper presents results useful in topological assessment of predures for initializing a gradient descent algorithm on this multimodal surface in the equalizer par

ISSN:0890-6327    

DOI:10.1002/acs.4480090402

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractRecursive identification algorithms based on the Wiener model are presented in this paper. They estimate the parameters of a SISO linear dynamic block in cascade with a known static output non‐linearity. Inversion of the non‐linear function is avoided and approximations of gradients are utilized. This allows an exact treatment of output measurement saturation and of situations where output measurements are obtained from sensors with relay‐type characteristics, such as EGO sensors in emission control systems for cars. Exact compensation for coarse quantization of output measurements can also be obtained by the algorithms. Stochastic averaging techniques using associated differential equations prove that local and global convergence of the schemes are tied to positive realness and sector conditions on the non‐linearity. Conditions for local convergence to the correct parameters are established for the case where the output non‐linearity is an arbitrary

ISSN:0890-6327    

DOI:10.1002/acs.4480090403

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractThis paper describes two non‐linear smoothing filters based on adaptive rank order filtering. the ideal output of these filters is a grey value suitable for characterizing the grey value distribution associated with the local texture, i.e. suitable for use as a region label for image segmentation purposes. the problem is to select as output a grey value that is stable with respect to the fluctuations of the local grey value distribution inside homogeneous regions. the first proposed method aims at the estimation of the mode of the local distribution. the second selects the output rank in dependence on the local average; it is simpler and combines the edge‐sharpening advantages of ‘comparison and selection filters’ with a better mode estimation, in comparison with the median filter, in the presence of asymmetrical local grey value distri

ISSN:0890-6327    

DOI:10.1002/acs.4480090404

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractAdaptive controllers applied to high‐speed and high‐precision robot manipulators give excellent tracking performances because they take into account the full dynamics of the robot. Recent publications have shown that on‐line estimation of the dynamic constant parameters can be obtained by the joint tracking error (direct adaptive control) or by the torque prediction error (indirect adaptive control).In direct adaptive controllers the estimation law is derived from Lyapunov stability or Popov hyperstability methods. These controllers are simple and their real‐time implementation is easy; however, the estimation is not so accurate. In indirect adaptive controllers the estimation law is based on a least squares algorithm. These controllers give accurate estimates of the manipulator parameters; however, they involve much more computation than the direct approach. Therefore no real‐time implementations of indirect adaptive tracking controllers for robots have been reported in the literature until now.This paper describes a real‐time implementation of an indirect adaptive scheme applied to a two‐degree‐of‐freedom (2DOF) direct‐drive SCAM robot. the controller is implemented at low cost by the use of a single‐chip digital s

ISSN:0890-6327    

DOI:10.1002/acs.4480090405

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

ISSN:0890-6327    

DOI:10.1002/acs.4480090406

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

ISSN:0890-6327    

DOI:10.1002/acs.4480090401

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY