An improved robot manipulator decentralized non-linear adaptive
controller that performs well in the presence of disturbances with
unknown parameters and non-linearities is presented in this work.
The proposed decentralized adaptive structure is a modification of
the controller developed by Seraji [13-17] and is characterized by an
auxiliary signal that compensates...
A new decentralized nonlinear controller for Robot Manipulators is
presented in this thesis. Based on concepts of Lyapunov stability theory and
some control ideas proposed in [3]-[7], we obtain continuous nonlinear
decentralized control laws which guarantee position and velocity tracking to
within an arbitrarily small error.
Assumptions based on physical...
A new algorithm is proposed which provides a sub-optimum near-far resistant
pattern for correlation with a known signal in a spread-spectrum multiple access
environment with additive white gaussian noise (AWGN). Only the patterns and
respective delays of the K-1 interfering users are required. The technique does not
require the inversion...
Long bridges tend to develop large deformations under the
action of intense dynamical loads such as wind or earthquakes.
Unless these deformations are controlled in some fashion, the
structure might suffer damage or even collapse. One possible
solution to this problem is to apply external forces to the
bridge through...
An adaptive decentralized nonlinear controller for a robot manipulator
is presented in this thesis. Based on the adaptive control schemes designed
by Seraji [18], Dai [30], and Jimenez [31], we redesigned and further
simplified the control algorithm and, as a consequence, we achieved better
path tracking performance.
The proposed adaptive...
A mathematical model of Limiting Dilution Analysis for two limiting
parameters is presented and investigated. Limiting Dilution Analysis is a microbiological
cell assay developed for immunological application. In the given
case we deal with the interaction between B lymphocytes, macrophage derived
factor and T-independent antigens. The state of the art...
Recent technical progress has made new forms of controller
implementations on computers possible. Especially the technique of Fuzzy Logic
Control has found a growing number of applications. Also the development of fast
A/D converters has made the acquisation of data with vision based systems
possible. In this project we combine...
The purpose of this thesis is to apply the wavelet transform WT to
multiresolution structures for analyzing the information content of images based on
multiresolution signal decomposition of the wavelet representation. The advantage
of the wavelet transform is the fact that it uses different building blocks than the
Fourier's sines...
IS-95, an interim standard proposed for future digital personal communications
systems, uses two levels of encoding of digital data for error control and compatibility
with code-division multiple access (CDMA) transmission. The data is first
convolutionally encoded and the resulting symbols are interleaved and then groups are
encoded as orthogonal Walsh...
An extremely important area that has enabled or will enable many of the
digital video services and applications such as VideoCD, DVD, DVC, HDTV, video
conferencing, and DSS is digital video compression. The great success of digital video
compression is mainly because of two factors. The state of the art...
This dissertation presents the continued study of a
non-iterative decision feedback (DF) receiver/decoder
design and its application to cellular communications or
wireless local loop systems based on the IS-95(-A)
standard of the Telecommunications Industry Association
and also Personal Communications Services systems based on
the American National Standards Institute standard J-STD-...
The widespread use of Wireless Local Area Networks (WLAN) and the desire for such products from different vendors to operate together has generated a movement towards standardization. Over the last decade, several organizations worldwide have researched and developed such standards, this includes the IEEE 802.11 committee. One of the important...
This document investigates, justifies, designs, and simulates the application of a fuzzy logic controller/optimizer in a sawmill bucking system application that is the first production station where stems coming from the mountains are processed in a sawmill. One of the areas of success in the application of fuzzy logic is...
Turbo codes have been used successfully for error correction in digital communications, however, their application to wireless mobile communications is still a fresh research topic. The objective of this thesis is to present a new solution that involves the usage of turbo codes, spatial diversity, and orthogonal complementary codes in...
Estimating the carrier frequency from a modulated waveform is one of the most important functions of a coherent signal receiver. Good performance and low bit error rates are obtained by coherent demodulation. Therefore, exact knowledge of the received signal carrier frequency is critical for communication systems. Also due to the...
There has been tremendous technological advancement in the area of high-speed indoor wireless local area networks (WLAN's) in recent years. All the existing tech- nologies such as IEEE 802.11a,b are bandwidth limited and high powered systems. The challenge any wireless technology faces is to minimize both the power consumption and...
In modern telecommunication applications, the need for high-reliability and high data rate is important because of factors such as a higher demand in multimedia capability of mobile devices and the exponentially increasing number of subscribers. Wireless communications in today’s technology have many limitations due to channel imperfections, which result in...
High data rate transmission has become an important challenge in today digital communication systems. One of the most difficult problems faced by engineers is to transmit data at sufficiently high rates through fading channels. This is the main motivation for the research presented herein. In this thesis, we investigate a...
Radio frequency (RF) power amplifiers (PA) are the most power consuming components of a mobile communications unit. They are used to convert the DC power from the battery into RF power delivered to the antenna. In a cell phone it becomes very important to use highly efficient power amplifiers, such...