123 research outputs found
MICROPROCESSOR BASED NON-LINEAR ADAPTIVE CONTROLLER
The advent of microprocessors has created the possibility of
developing low cost adaptive controllers for small process plants
which in the past badly needed but could not afford such
controllers. To examine the practicality of developing advanced
low cost microprocessor based controller, this thesis describes
the development of a non-linear adaptive controller for a nylon
crimping plant which is a typical example of small process
plants.
In order to test the algorithm on site, an algorithm
development/implement device basing on a novel multi-tasking
concept was developed. This novel microprocessor based device
can perform program development, on-line algorithm test and data
logging at the same time, while, still maintaining its small size
for easy transportation. When the control algorithm was fully
developed and tested, a low cost dedicated controller using an
Intel 8085 processor was designed to house the algorithm and as a
direct replacement of the original analogue controller
Pneumatic motion control systems for modular robots
This thesis describes a research study in the design,
implementation, evaluation and commercialisation of
pneumatic motion control systems for modular robots. The
research programme was conducted as part of a collaborative
study, sponsored by the Science and Engineering Research
Council, between Loughborough University and Martonair (UK)
Limited.
Microprocessor based motion control strategies have been
used to produce low cost pneumatic servo-drives which can be
used for 'point-to-point' positioning of payloads. Software
based realtime control strategies have evolved which
accomplish servo-controlled positioning while compensating
for drive system non-linearities and time delays. The
application of novel compensation techniques has resulted in
a significant improvement in both the static and dynamic
performance of the drive.
A theoretical foundation is presented based on a
linearised model of a pneumatic actuator, servo-valve, and
load system. The thesis describes the design and evolution
of microprocessor based hardware and software for motion
control of pneumatic drives. A British Standards based
test-facility has allowed control strategies to be evaluated
with reference to standard performance criteria.
It is demonstrated in this research study that the dynamic
and static performance characteristics of a pneumatic motion
control system can be dramatically improved by applying
appropriate software based realtime control strategies. This
makes the application of computer controlled pneumatic
servos in manufacturing very attractive with cost
performance ratios which match or better alternative drive
technologies.
The research study has led to commercial products
(marketed by Martonair Ltd), in which realtime control
algorithms implementing these control strategy designs are
executed within a microprocessor based motion controller
Active aging in place supported by caregiver-centered modular low-cost platform
Aging in place happens when people age in the residence of their choice, usually their homes because
is their preference for living as long as possible. This research work is focused on the
conceptualization and implementation of a platform to support active aging in place with a particular
focus on the caregivers and their requirements to accomplish their tasks with comfort and supervision.
An engagement dimension is also a plus provided by the platform since it supports modules to make
people react to challenges, stimulating them to be naturally more active. The platform is supported
by IoT, using low-cost technology to increment the platform modularly. Is a modular platform capable
of responding to specific needs of seniors aging in place and their caregivers, obtaining data regarding
the person under supervision, as well as providing conditions for constant and more effective
monitoring, through modules and tools that support decision making and tasks realization for active
living. The constant monitoring allows knowing the routine of daily activities of the senior. The use
of machine learning techniques allows the platform to identify, in real-time, situations of potential
risk, allowing to trigger triage processes with the older adult, and consequently trigger the necessary
actions so that the caregiver can intervene in useful time.O envelhecimento no local acontece quando as pessoas envelhecem na residência da sua escolha,
geralmente nas suas próprias casas porque é a sua preferência para viver o máximo de tempo possível.
Este trabalho de investigação foca-se na conceptualização e implementação de uma plataforma de
apoio ao envelhecimento ativo no local, com particular enfoque nos cuidadores e nas suas
necessidades para cumprir as suas tarefas com conforto e supervisão. Uma dimensão de engajamento
também é um diferencial da plataforma, pois esta integra módulos de desafios para fazer as pessoas
reagirem aos mesmos, estimulando-as a serem naturalmente mais ativas. A plataforma é suportada
por IoT, utilizando tecnologia de baixo custo para incrementar a plataforma de forma modular. É uma
plataforma modular capaz de responder às necessidades específicas do envelhecimento dos idosos no
local e dos seus cuidadores, obtendo dados relativos à pessoa sob supervisão, bem como fornecendo
condições para um acompanhamento constante e mais eficaz, através de módulos e ferramentas que
apoiam a tomada de decisões e realização de tarefas para a vida ativa. A monitorização constante
permite conhecer a rotina das atividades diárias do idoso, permitindo que, com a utilização de técnicas
de machine learning, a plataforma seja capaz de detetar em tempo real situações de risco potencial,
permitindo desencadear um processo de triagem junto do idoso, e consequentemente despoletar as
ações necessárias para que o prestador de cuidados possa intervir em tempo útil
Distillation column dynamics and control
A pilot plant scale, atmospheric pressure, sieve plate distillation column was constructed and fully instrumented. Novel speed controllable pumps were used to control liquid flows. A microcomputer was constructed to provide local and hierarchical control of the column. The microcomputer included an operator console, a 16 channel data acquisition unit, a 4 channel control output unit, and a hardware arithmetic processor. A software development system was assembled by linking the microcomputer to a minicomputer. Software written for the development system included a cross-assembler, a transfer program, and a microcomputer control program. A binary steady state distillation column model was developed, solved on a digital computer, and verified against experimental data using a binary mixture of methanol and water.
Two control schemes were investigated using only the microcomputer resources. A multi-loop system using digital PI controllers was found to give excellent control within the accuracy of the instrumentation.
An adaptive feedforward controller was proposed and verified using a steady state model, and experiments. The results were good, but because of the relatively simple dynamics of the experimental column, the feedforward controller was no better than the feedback controllers.
A microcomputer control system has been shown to be an effective replacement for conventional analog control on a distillation column. The computing power of the microcomputer has enabled a sophisticated control scheme to be implemented at low cost
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