35 research outputs found
Adaptive control system of slotless DC linear motor
Slotless DC linear motors (SDCLM) offer several benefits over traditional linear motors,
including higher efficiency, smoother operation, and higher power density. These
advantages make them a popular choice for a wide range of applications in various
industries. One of the main benefits of a slotless DC linear motor is the absence of slot
harmonics, which can cause vibration and noise in traditional slotted motors. This makes
slotless motors ideal for applications that require precise and smooth motion, such as in
medical equipment, robotics, and semiconductor manufacturing. However, one of the
challenges of a Slotless DC linear motor is the presence of force ripple, which can limit the
motor's performance, precision, and accuracy. Force ripple is caused by the mutual
attraction of the translator's magnets and iron cores. It is independent of the motor current
and is determined only by the relative position of the motor coils regarding the magnets. To
overcome these challenges, motor redesign, magnetic field optimisation and the use of an
adaptive control system.
This research program focused on and investigated the above possible methods (i.e., motor
redesign, magnetic field optimisation field and use of advanced control algorithms such as
Sliding Mode Control SMC) to tackle the current challenges and improve the relevant
industrial application performance and precision. The inquiry encompasses the analysis,
design, and control of the SDCLM by proper modelling, building, and experimental
validation of the modelled findings, applying both static and dynamic methodologies.
Electrical, mechanical, and magnetic analyses were performed on the SDCLM design.
The performance of the SDCLM was investigated using a finite element method (FEM),
and the motor parameters were improved. Investigation and analysis are performed about
additional difficulties such as force ripple and normal force, where the results indicated that
the flux density in the airgap and the thrust force were different between the actual time and
the simulation by 7.14% and 8.07%, respectively. Moreover, sliding mode control is
designed to achieve desired system performance, such as reducing the power ripple of a
slotless DC linear motor. where the proposed control shows experiments that it has stability
despite disturbances and uncertainties.
To improve the control method and reduce the steady-state error caused by the force
ripple, the Bees algorithm has been used to tune the parameters of the controller.
Finally, the outcomes indicate that the control method employing the disturbance
observer and Bees algorithm has enhanced the performance of both position and speed,
while concurrently reducing the force ripple. A comparison between simulation and
experiment shows that there is a difference in the tracking performance, where the
difference was around 13.6%. This error could have arisen from the omission of certain
errors that cannot be accounted for within the simulation. These errors may stem from issues
with the position sensor or discrepancies in the manual system design process
Design Of Linear Generator
The objective of this project is to design and develop a prototype of linear motor that could be used to convert
mechanical energy into electrical energy and back. In this project. the desired deliverables is a hardware development of linear generator/motor that will produce sufficient electrical energy from a sustained mechanical motion. The challenge of this project is to design a moving iron linear generator that can induce sufficient magnetic flux to produce significant electrical energy
Intelligent instrumentation, control and monitoring of precision motion systems
Ph.DDOCTOR OF PHILOSOPH
Design, construction and control of a unidirectional tele-operated seismic simulator for testing small scale structural models
Este artículo presenta el diseño, construcción y control de un simulador sísmico uniaxial para modelos
estructurales de pequeña escala. Inicialmente, el documento muestra el diseño de cada parte del simulador
hasta llegar a la construcción de todo el prototipo. Luego, se halla un modelo matemático del simulador
utilizando un procedimiento de identificación en el lazo de velocidad que se valida mediante respuesta en
frecuencia. A partir del modelo identificado se diseñan los controladores de los lazos de velocidad y
posición, que proveen al sistema el desempeño requerido. Finalmente, se presentan varias pruebas para la
validación del simulador sísmico y se describe la interfaz de control remota desarrollada en Java®, que
permite al usuario definir las señales de excitación, visualizar los registros obtenidos de la prueba y
observar el video en línea desde Internet
Nonlinear Time-Frequency Control of Permanent Magnet Electrical Machines
Permanent magnet (PM) electrical machines have been widely adopted in
industrial applications due to their advantages such as easy to control, compact in size,
low in power loss, and fast in response, to name only a few. Contemporary control
methods specifically designed for the control of PM electrical machines only focus on
controlling their time-domain behaviors while completely ignored their frequency-domain
characteristics. Hence, when a PM electrical machine is highly nonlinear, none of them
performs well.
To make up for the drawback and hence improve the performance of PM electrical
machines under high nonlinearity, the novel nonlinear time-frequency control concept is
adopted to develop viable nonlinear control schemes for PM electrical machines. In this
research, three nonlinear time-frequency control schemes are developed for the speed and
position control of PM brushed DC motors, speed and position control of PM synchronous
motors, and chaos suppression of PM synchronous motors, respectively. The most
significant feature of the demonstrated control schemes are their ability in generating a
proper control effort that controls the system response in both the time and frequency
domains. Simulation and experiment results have verified the effectiveness and superiority
of the presented control schemes. The nonlinear time-frequency control scheme is
therefore believed to be suitable for PM electrical machine control and is expected to have
a positive impact on the broader application of PM electrical machines
Modeling of precision motion control systems: a relay feedback approach
Ph.DDOCTOR OF PHILOSOPH
Microprocessor-controlled brushless DC linear stepping motor
Presently, there is a rapidly growing research interest for an efficient, high thrust density and high thrust to input power electrical linear machine. However, only limited work has been carried out in terms of the development of brushless DC linear motors (BDCLM). Focusing on this research gap which presently exist in this field, this thesis makes the development of the BDCLM the research objective, in order to produce a large thrust to input power, compared to the already existing designs. The motor is designed in such way that the motor core accommodates twenty-four independent multi-layer coil sections wound with enamelled copper wire and each layer section has 470 turns without compromising the effective air-gap. Also, a design commutation algorithm to provide a smooth movement and a high thrust for the BDCLM is implemented.
The design, analysis and optimization of the BDCLM in applications that requires a high thrust to input current ratio is described in this project. The investigation includes; the analysis, design, and control of the BDCLM through appropriate modelling, construction and experimental validation of the modelled results, employing both the static and dynamic approaches. The BDCLM design was analysed from electrical, mechanical and magnetic perspectives.
A Finite Element Method (FEM) was used to predict the performance of the BDCLM and to optimise the motor parameters. Additional challenges such as force ripple and normal force are investigated and analysed. A Proportional Integral Derivative (PID) control system, based on an Arduino Mega board is used to control the motor speed and position. A graphical user interface (GUI) is built in LabVIEW environment to control the Arduino board.
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The experimental results were within 8.9 %, 2 % and 3 % of the modelled results with respect to the motor thrust, speed and position. These results demonstrate a good agreement between the two approaches. This research work can be considered as an initial step to developing the BDCLM for commercial applications
Nonlinear Time-Frequency Control of Permanent Magnet Electrical Machines
Permanent magnet (PM) electrical machines have been widely adopted in
industrial applications due to their advantages such as easy to control, compact in size,
low in power loss, and fast in response, to name only a few. Contemporary control
methods specifically designed for the control of PM electrical machines only focus on
controlling their time-domain behaviors while completely ignored their frequency-domain
characteristics. Hence, when a PM electrical machine is highly nonlinear, none of them
performs well.
To make up for the drawback and hence improve the performance of PM electrical
machines under high nonlinearity, the novel nonlinear time-frequency control concept is
adopted to develop viable nonlinear control schemes for PM electrical machines. In this
research, three nonlinear time-frequency control schemes are developed for the speed and
position control of PM brushed DC motors, speed and position control of PM synchronous
motors, and chaos suppression of PM synchronous motors, respectively. The most
significant feature of the demonstrated control schemes are their ability in generating a
proper control effort that controls the system response in both the time and frequency
domains. Simulation and experiment results have verified the effectiveness and superiority
of the presented control schemes. The nonlinear time-frequency control scheme is
therefore believed to be suitable for PM electrical machine control and is expected to have
a positive impact on the broader application of PM electrical machines