Conventional Gradient Algorithm Research Articles

Algorithms of adaptive disturbance compensation in linear systems with arbitrary input delay

ABSTRACT The problem of direct adaptive compensation of a priori uncertain disturbances for general class of linear time-invariant plans with known parameters and arbitrarily known input delay is considered. The external disturbance is assumed to be unmeasurable and modelled as the output of uncertain autonomous linear system. A scheme with two different algorithms of adaptive disturbance compensation is proposed. The scheme is based on special disturbance observer and predictor. The first algorithm involves the conventional gradient algorithm of adaptation with restricted convergence properties. The second algorithm represents the modification of gradient algorithm and accumulates information about disturbance over past period of time. Accumulation is implemented via a preselected linear operator with memory and gives dramatically improved parametric convergence. For algorithms of adaptation, the influence of input delay is completely compensated by the use of a special scheme of error augmentation. The problem of plant stabilisation is resolved by involving the state predictor. The performance of the proposed schemes of disturbance compensation is demonstrated via simulation and compared in conclusion.

Cooperative behavior of nano-robots as an analogous of the quantum harmonic oscillator

A multi-robot system that consists of N nano-robots is studied. It is assumed that the robots correspond to diffusing particles, and interact to each other as the theory of Brownian motion predicts. Brownian motion is the analogous of the quantum harmonic oscillator (Q.H.O.), i.e., of Schrodinger's equation under harmonic (parabolic) potential. It is shown that the motion of the robots can be described by Langevin's equation which is a stochastic linear differential equation. It is proved that Langevin's equation is a generalization of conventional gradient algorithms. Therefore the kinematic models of mobile robots which follow conventional gradient algorithms can be considered as a subcase of the kinematic models which are derived from the diffusion analogous of the Q.H.O model.

Microwave imaging of a perfectly conducting cylinder with the use of a simulated annealing approach

In this Letter we suggest an iterative imaging technique based on a simulated annealing (SA) algorithm for a perfectly conducting cylinder. It is numerically shown that an imaging technique that uses SA does not require prior knowledge regarding the center and the shape of an object, whereas one that uses conventional gradient algorithms does require this knowledge regarding a scatterer. It is also shown via numerical simulations that this technique is very insensitive to noise in the scattered field and is not much affected by the observation locations. © 1996 John Wiley & Sons, Inc.

Microwave imaging of a perfectly conducting cylinder with the use of a simulated annealing approach

In this Letter we suggest an iterative imaging technique based on a simulated annealing (SA) algorithm for a perfectly conducting cylinder. It is numerically shown that an imaging technique that uses SA does not require prior knowledge regarding the center and the shape of an object, whereas one that uses conventional gradient algorithms does require this knowledge regarding a scatterer. It is also shown via numerical simulations that this technique is very insensitive to noise in the scattered field and is not much affected by the observation locations. © 1996 John Wiley & Sons, Inc.

Parameters Adaptive Control Algorithms for Data Transmission

New effective algorithms for adaptive control of parameters in the linear part of the on modem receiver using in a data transmission are discribed in this paper. Ones provide an independent control of the gain K, vector equaliser coefficients C, phase of a carrier φ and phase of a sampling τ. These orthogonal algorithms give the better quality criterion with comparison the conventional gradient algorithms at high speed data communication by the way deleting the redundancy.