Advanced Fault Diagnosis and Health Monitoring Techniques for Complex Engineering Systems

Over the last few decades, the field of fault diagnostics and structural health management has been experiencing rapid developments. The reliability, availability, and safety of engineering systems can be significantly improved by implementing multifaceted strategies of in situ diagnostics and prognostics. With the development of intelligence algorithms, smart sensors, and advanced data collection and modeling techniques, this challenging research area has been receiving ever-increasing attention in both fundamental research and engineering applications. This has been strongly supported by the extensive applications ranging from aerospace, automotive, transport, manufacturing, and processing industries to defense and infrastructure industries

An Online Lab for Digital Electronics Course Using Information Technology Supports

This study is an implementation of information technology for education, aimed to produce a model of online lab course with a collaborative environment using a desktop sharing application. In the digital electronics lab course, participants were divided into the groups, each of them consists of three members. A desktop sharing application was used to the digital circuit simulator as an offline program that can be accessed online. The results show that the application can be used to introduce a collaborative environment in an online lab course. The application was possible to make an offline program such of a digital circuit simulator that can be accessed online by each member of the groups. This model has got a positive response from the participants of digital electronics lab course

Validating the Operating Window Concept for Robustness on a Circuit Board Stencil Printing Process

The lifecycle of a system is dependent on the system design. However, the concern with quality has been stressed mostly during its production and use. The understanding of the system variability generated by noise variables shifted the quality focus to the design phase. The development of robustness early on the system lifecycle increases the system reliability through its entire life cycle. Although the robust design approach developed by the Taguchi methods application had a great contribution to this philosophy, there is much criticism of this methodology. One alternative to the Taguchi method is the Operating Window methodology. Its application has successfully been demonstrated as a substitute for the Taguchi methods, especially when the response is not quantitative. However, most of the examples were used repeatedly and the steps on the application of the methodology have not been well detailed. Therefore, this project had the objective of developing a unique application of the methodology with a simple approach. Moreover, with the implementation of the methodology, the project aims to identify the difference between a design with a wide output data distribution and a design with a narrow distribution. The methodology followed the Operating Window methodology steps, applying it to a circuit board printing process. The results have shown that it is possible to have a relationship between the Operating Window range and the distribution variation from the system output

Design of smart tool organizer

The increasing demand for compact and energy efficient machines and mechanisms, led to the emergence of a series of scalable instruments and devices used for testing, storage, manufacturing, and prototyping. The emergence of these devices indeed provided the flexibility and low capital cost that were necessary for product development and personal use. Furthermore, the demand is expected to proliferate to all domestic and industrial sectors of the economy, which brings us to the subject of the current investigation. The main objective of the proposed project is the design and prototyping of a compact electromechanical smart tool organizer that is capable of storing, tracking personal use and availability of machine shop tools in the college of Mathematics and Science at the University of Central Oklahoma. The proposed design incorporates a micro-controlled electro-mechanical dispensing unit, an interactive digital interface with key activation and a database for data collection & tracking of tools and personnel users. The dispensing unit consists of a CNC machine, linear actuator and a 3D printed mechanical clamp which enables the unit to efficiently hold and move various tools to the desired location. The skeleton of the CNC machine is assembled using five stainless steel v-slots operating on a belt and pinion system. Pinons are fitted to NEMA 17 stepper motors to achieve 2D motion by converting rotational motion to linear motion using a belt driven actuator. The assembly of the CNC machine utilizes various gantry plates to hold v-slots in position along with providing mounts for stepper motors and linear actuator. The linear actuator acts as a third axis which allows the motion of the dispensing unit to operate in three directions. This provides mobility to the machine to precisely take the mechanical clamp to a predetermined position within the frame of the dispensing unit. The design of mechanical clamp includes assembly of the base of the clamp, rack and pinion system, two gripper arms and a servo motor. The pinion converts the rotational motion to linear motion of the racks enabling the grip to open and close as required. The final assembly of the mechanical clamp is mounted on the linear actuator using the 3D printed mount bracket on the base of the clamp. The electronics and controls of the smart tool organizer includes low and high voltage operating components such as Nema 17 stepper motors, MG996R servo, linear actuator, limit switches, buck converter, DS3231 RTC module, SD card module, L298N motor drive module, TB6600 motor drivers, a 7” touch screen LED display and an arduino mega. The firmware arduino IDE is used to program these electronic components and ASCII is used to program the Interactive GUI and HMI on the Nextion display which connect to arduino using serial port and synchronizes to achieve the goal of the smart tool organizer

Design and Construction of a Moving Cassette Electronic Gear-Shift for Human Powered Vehicles

In this article, the design and implementation of an electronic bicycle gear-shift with moving cassette is presented. The niche context where the needs developed is explained and the project evolution over two versions is described. Technical aspects considered in the design phase are discussed and detailed explanations of hardware layout and control software logic are given. Performance of the two implemented versions are compared through data recorded during the target competition (pedaling cadence and torque), highlighting the higher reliability of the second design thanks to mechanical simplification and a more stable position feedback. An additional comparison with cadence data from other competitors in a speed-challenge competition is then presented to highlights the main benefit obtained: a reduced variance in cadence that enables the rider to pedal at his optimal rate since the early stage and through the whole run-up. Finally, the current development of the project under a Proof of Concept grant is presented by discussing its potential application on the standard bicycle market, the need for an assessment of its value proposition and the main obstacles to overcome for complying (or not) with the current market standards. The article offers an overview of practical aspects to be considered when designing high-speed human powered vehicle transmissions, including technical details of an innovative solution and critical considerations about the possibility of such a specific design to develop within the standard bicycle market

Advanced control system for stand-alone diesel engine driven-permanent magnetic generator sets

The main focus is on the development of an advanced control system for variable speed standalone diesel engine driven generator systems. An extensive literature survey reviews the historical development and previous relevant research work in the fields of diesel engines, electrical machines, power electronic converters, power and electronic systems. Models are developed for each subsystem from mathematical derivations with necessary simplifications made to reduce complexity while retaining the required accuracy. Initially system performance is investigated using simulation models in Matlab/Simulink. The AC/DC/AC power electronic conversion system used employs a voltage controlled dc link. The ac voltage is maintained at constant magnitude and frequency by using a dc-dc converter and a fixed modulation ratio VSI PWM inverter. The DC chopper provides fast control of the output voltage by dealing efficiently with transient conditions. A Variable Speed Fuzzy Logic Core (VSFLC) controller is combined with a classical control method to produce a novel hybrid controller. This provides an innovative variable speed control that responds to both load and speed changes. A new power balance based control strategy is proposed and implemented in the speed controller. Subsequently a novel overall control strategy is proposed to co-ordinate the hybrid variable speed controller and chopper controller to provide overall control for both fast and slow variations of system operating conditions. The control system is developed and implemented in hardware using Xilinx Foundation Express. The VHDL code for the complete control system design is developed and the designs are synthesised and analysed within the Xilinx environment. The controllers are implemented with XC95108-PC84 and XC4010-PC84 to provide a compact and cheap control system. A prototype experimental system is described and test results are obtained that show the combined control strategy to be very effective. The research work makes contributions in the areas of automatic control systems for diesel engine generator sets and CPLD/FPGA application that will benefit manufacturers and consumers.EPSR

Third International Symposium on Magnetic Suspension Technology

In order to examine the state of technology of all areas of magnetic suspension and to review recent developments in sensors, controls, superconducting magnet technology, and design/implementation practices, the Third International Symposium on Magnetic Suspension Technology was held at the Holiday Inn Capital Plaza in Tallahassee, Florida on 13-15 Dec. 1995. The symposium included 19 sessions in which a total of 55 papers were presented. The technical sessions covered the areas of bearings, superconductivity, vibration isolation, maglev, controls, space applications, general applications, bearing/actuator design, modeling, precision applications, electromagnetic launch and hypersonic maglev, applications of superconductivity, and sensors

Development of a Two-Wheel Inverted Pendulum and a Cable Climbing Robot

The research work in this thesis constitutes two parts: one is the development and control of a Two-wheel inverted pendulum (TWIP) robot and the other is the design and manufacturing of a cable climbing robot (CCR) for suspension bridge inspection. The first part of this research investigates a sliding mode controller for self-balancing and stabilizing a two-wheel inverted pendulum (TWIP) robot. The TWIP robot is constructed by using two DC gear motors with a high-resolution encoder and zero backlashes, but with friction. It is a highly nonlinear and unstable system, which poses challenges for controller design. In this study, a dynamic mathematical model is built using the Lagrangian function method. And a sliding mode controller (SMC) is proposed for auto-balancing and yaw rotation. A gyro and an accelerometer are adopted to measure the pitch angle and pitch rate. The effect on the sensor’s installation location is analyzed and compensated, and the precision of the pose estimation is improved accordingly. A comparison of the proposed SMC controller with a proportional-integral-derivative (PID) controller and state feedback controller (SFC) with linear quadratic regulation (LQR) has been conducted. The simulation and experimental test results demonstrate the SMC controller outperforms the PID controller and SFC in terms of transient performance and disturbance rejection ability. In the second part of the research, a wheel-based cable climbing robotic system which can climb up and down the cylindrical cables for the inspection of the suspension bridges is designed and manufactured. Firstly, a rubber track climbing mechanism is designed to generate enough adhesion force for the robot to stick to the surface of a cable and the driving force for the robot to climb up and down the cable, while not too big to damage the cable. The climbing system includes chains and sprockets driven by the DC motors and adhesion system. The unique design of the adhesion mechanism lies in that it can maintain the adhesion force even when the power is lost while the system works as a suspension mechanism. Finally, a safe-landing mechanism is developed to guarantee the safety of the robot during inspection operations on cables. The robot has been fully tested in the inspection of Xili bridge, Guangzhou, P.R. China

A prototype of an energy-efficient MAGLEV train : a step towards cleaner train transport

The magnetic levitation (MAGLEV) train uses magnetic field to suspend, guide, and propel vehicle onto the track. The MAGLEV train provides a sustainable and cleaner solution for train transportation by significantly reducing the energy usage and greenhouse gas emissions as compared to traditional train transportation systems. In this paper, we propose an advanced control mechanism using an Arduino microcontroller that selectively energizes the electromagnets in a MAGLEV train system to provide dynamic stability and energy efficiency. We also design the prototype of an energy-efficient MAGLEV train that leverages our proposed control mechanism. In our MAGLEV train prototype, the levitation is achieved by creating a repulsive magnetic field between the train and the track using magnets mounted on the top-side of the track and bottom-side of the vehicle. The propulsion is performed by creating a repulsive magnetic field between the permanent magnets attached on the sides of the vehicle and electromagnets mounted at the center of the track using electrodynamic suspension (EDS). The electromagnets are energized via a control mechanism that is applied through an Arduino microcontroller. The Arduino microcontroller is programmed in such a way to propel and guide the vehicle onto the track by appropriate switching of the electromagnets. We use an infrared-based remote-control device for controlling the power, speed, and direction of the vehicle in both the forward and the backward direction. The proposed MAGLEV train control mechanism is novel, and according to the best of our knowledge is the first study of its kind that uses an Arduino-based microcontroller system for control mechanism. Experimental results illustrate that the designed prototype consumes only 144 W-hour (Wh) of energy as compared to a conventionally designed MAGLEV train prototype that consumes 1200 Wh. Results reveal that our proposed control mechanism and prototype model can reduce the total power consumption by 8.3 x as compared to the traditional MAGLEV train prototype, and can be applied to practical MAGLEV trains with necessary modifications. Thus, our proposed prototype and control mechanism serves as a first step towards cleaner engineering of train transportation systems

DESIGN, DEVELOPMENT, AND USABILITY EVALUATION OF CONTROL ALGORITHMS FOR A MOBILITY ENHANCEMENT ROBOTIC WHEELCHAIR (MEBOT)

An Electric Powered Wheelchair (EPW) is a key mobility device for people with disabilities providing mobility, independence, and improved quality of life. However, the design of current EPWs remains limited when driving in environments with architectural barriers and uneven terrain, making EPW users susceptible to safety issues - such as tipping or falling - which may lead to serious injury. To overcome these limitations, we developed a series of control algorithms for a novel mobility enhancement robotic wheelchair (MEBot). MEBot consists of six wheels with pneumatic actuators to control the elevation and inclination of the wheelchair as well as electric actuators in the driving wheel carriage to change its driving wheel configuration. Its controller is comprised of a single board computer, and a sensor package that aids obstacle detection and provides information about joint movements to develop MEBOT’s control algorithms. The ability of the MEBot controller to perform control algorithms, such as the dynamic seat leveling, curb climbing, and descending applications, was evaluated and validated in both simulation and a controlled environment for broader accessibility in architectural barriers. A stability analysis showed that while the footprint of the wheelchair changed during the process of its control algorithms when overcoming architectural barriers such as curbs and slopes; MEBot maintained its center of mass within the wheelchair footprint. Furthermore, a usability evaluation with ten power wheelchair users was conducted to compare the MEBot’s controller with that of their own power wheelchair in simulated indoor, outdoor, and advanced (architectural barriers) environments. Results show that MEBot was able to perform a significantly higher number of tasks than currently available commercial power wheelchairs in the advanced environment. In addition, participant’s feedback was obtained for further improvement of the device and its control algorithms