Failure of autonomous maintenance program at the Gqeberha food manufacturing plant
- Authors: Moloi, Tshepo
- Date: 2024-12
- Subjects: Automatic control , Process control , Food industry and trade -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/70078 , vital:78290
- Description: The main emphasis of this research is on the identification of the main factors explaining the difficulties and failure of Autonomous Maintenance (AM) program implementation from the year 2018 to 2024. This qualitative study focuses on a Port Elizabeth, South Africa food processing company that has implemented an AM program. The lack of success attained in staff training after the implementation phase drove this investigation. This study was carried out to provide first-hand evidence of the pragmatic difficulties in the execution of the AM program. Three main goals defined the research: first, to find the problems that emerged during the AM implementation; second, to investigate the inadequacy of the training program in equipping workers with the necessary skills and competencies to successfully carry out AM; and thirdly, to get valuable opinions on possible enhancements or alternative approaches to the implementation phase of AM from operators, line leaders, and analysts. There is an existing research vacuum as nothing is known about how training affects the implementation of AM in food processing plants especially in South Africa. Purposive sampling selected thirty persons. Thirteen process operators, nine technical operators, six-line leaders, two preventive maintenance owners, and a senior management representative made comprised the group. Extensive in-person interviews with operators, line leaders, and top management gathered the data. Thematic analysis was used to examine the data even further to pinpoint the main themes that emerged. Six main topics found in this research best capture the difficulties faced by a food processing company using AM. The problems were poor training, limited time and resources, lack of motivation and rewards, ineffective communication, involvement, and accountability; management gave production priority over autonomous maintenance; and there was no culture of dedication. Several factors contribute to the ineffectiveness of the training program in enabling employees with the required skills to implement AM: the lack of practical examples to support theoretical ideas, limited resources, trainers lacking expertise in their respective fields, which limits understanding. The main emphasis of this research is on the identification of the main factors explaining the difficulties throughout the implementation period. Moreover, this research improves the body of information already in use by stressing the inadequacies of the training program in developing important skills. Helping AM operators and line supervisors understand the difficulties they faced is the primary goal of the research. Top executives will be offered the recommendations for improving and maximizing the AM program. Understanding the training needs for operators will help production managers and human resources professionals to guarantee their successful training and efficient application of the program. Operations management experts in academia have thorough understanding of AM including theoretical ideas, pragmatic implementation, and the difficulties using successful strategies. The key limitation was the narrow focus of the research, which mainly looked at people within the production line of the model line to understand the problems that emerged during the implementation of autonomous maintenance. The generalisation of the results to the whole workforce is not achieved due to the exclusion of employees from other areas of the factory. The company wants to start a thorough training program with a cross-functional team to enhance operator communication. The main topics explaining the problems in the training program is another disadvantage. This will be a strong basis for further studies. , Thesis (MBA) -- Faculty of Business and Economic Sciences, Business School, 2024
- Full Text:
- Date Issued: 2024-12
Design of a dedicated IFT microcontroller
- Authors: Himunzowa, Grayson
- Date: 2018
- Subjects: Feedback control systems , Automatic control , Engineering design -- Data processing
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/30017 , vital:30809
- Description: The design of a Dedicated IFT Microcontroller originated from the successful implementation of the Iterative Feedback Tuning (IFT) technique into the Digital Signal Processor microcontroller (DSP56F807C) at the University of Cape Town in 2006. However, implementation of the IFT technique on a general-purpose microcontroller is neither optimal, nor a cost-effective exercise, as most of the microcontroller peripherals remain unused, and drain energy for doing nothing. In addition, microcontrollers and DSPs are software-driven devices whose nature is sequential in executing algorithms, and hence have a significant effect on the bandwidth of the closed-loop control. To mitigate the said problem, the design of a Dedicated IFT Microcontroller is proposed in this thesis. To accomplish this goal, the preliminary task was to explore the IFT theory and its applications, followed by a review of the literature on FPGA design methodology for industrial control systems, Microcontroller design principles, and FPGA theory and trends. Furthermore, a survey of electronic design automation (EDA) tools and other application software was also conducted. After the literature review, the IFT was investigated exhaustively by applying it to three types of plants, namely: a DC motor, an oscillatory plant, and an unstable plant. Each of these plants were tested using three types of initial controllers, namely heavilydamped, critically damped and under-damped initial controllers. The plants were also tested by varying the amplitude of the reference signal, followed by using a single-step signal of constant amplitude of one volt. The intention of exploring all of these possibilities was meant to firmly expose the IFT boundaries of applicability, so that the final product would not be vulnerable to unnecessary post-production discoveries. The design methodology adopted in this research was a popular hierarchical and modular top-down procedure, which is an array of abstraction levels that are detailed as: system level, behavioural level, Register-Transfer Level (RTL) and Gate level. At system level, the Dedicated IFT Microcontroller was defined. Thereafter, at behavioural level, the design was simulated using VHDL, created by porting the LabView IFT code to the Xilinx EDA tool. At the RTL, the synthesisable VHDL code utilising fixed-point number representation was written. The compiled bit file was downloaded onto National Instruments (NI) Digital Electronics FPGA Board featuring iii the Spartan 3 series FPGA. This was tested, using a method known as simulation in the hardware. The key contribution of this thesis is the experimental validation of the IFT technique on FPGA hardware as it has never been published before, the work described in chapter four and five. The other contribution is the analysis of 1DOF IFT technique in terms of limitations of applicability for correct implementation, which is the main work of chapter three. This work could be used to explore other computational methods, like the use of floating-point number representation for high resolution and accuracy in numerical computations. Another avenue that could be exploited is Xilinx's recent Vivado methodology, which has the capacity for traditional programming languages like C or C++, as these have in-built floating-point number capability. Finally, out of this work, two papers have already been published by Springer and IEEE Xplore Publishers, and a journal paper has also been written for publication in the Control Systems Technology journal.
- Full Text:
- Date Issued: 2018
A fuzzy logic control system for a friction stir welding process
- Authors: Majara, Khotso Ernest
- Date: 2006
- Subjects: Friction welding , Fuzzy logic , Automatic control , Fuzzy systems
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9594 , http://hdl.handle.net/10948/405 , Friction welding , Fuzzy logic , Automatic control , Fuzzy systems
- Description: FSW is a welding technique invented and patented by The Welding Institute in 1991. This welding technique utilises the benefits of solid-state welding to materials regarded as difficult to weld by fusion processes. The productivity of the process was not optimised as the real-time dynamics of the material and tool changes were not considered. Furthermore, the process has a plastic weld region where no traditional modelling describing the interaction between the tool and work piece is available. Fuzzy logic technology is one of the artificial intelligent strategies used to improve the control of the dynamics of industrial processes. Fuzzy control was proposed as a viable solution to improve the productivity of the FSW process. The simulations indicated that FLC can use feed rate and welding speed to adaptively regulate the feed force and tool temperature respectively, irrespective of varying tool and material change. The simulations presented fuzzy logic technology to be robust enough to regulate FSW process in the absence of accurate mathematical models.
- Full Text:
- Date Issued: 2006
Intelligent gripper design and application for automated part recognition and gripping
- Authors: Wang, Jianqiang
- Date: 2002
- Subjects: Automatic control , Robots, Industrial , Robotics
- Language: English
- Type: Thesis , Doctoral , DTech (Engineering)
- Identifier: vital:10816 , http://hdl.handle.net/10948/102 , Automatic control , Robots, Industrial , Robotics
- Description: Intelligent gripping may be achieved through gripper design, automated part recognition, intelligent algorithm for control of the gripper, and on-line decision-making based on sensory data. A generic framework which integrates sensory data, part recognition, decision-making and gripper control to achieve intelligent gripping based on ABB industrial robot is constructed. The three-fingered gripper actuated by a linear servo actuator designed and developed in this project for precise speed and position control is capable of handling a large variety of objects. Generic algorithms for intelligent part recognition are developed. Edge vector representation is discussed. Object geometric features are extracted. Fuzzy logic is successfully utilized to enhance the intelligence of the system. The generic fuzzy logic algorithm, which may also find application in other fields, is presented. Model-based gripping planning algorithm which is capable of extracting object grasp features from its geometric features and reasoning out grasp model for objects with different geometry is proposed. Manipulator trajectory planning solves the problem of generating robot programs automatically. Object-oriented programming technique based on Visual C++ MFC is used to constitute the system software so as to ensure the compatibility, expandability and modular programming design. Hierarchical architecture for intelligent gripping is discussed, which partitions the robot’s functionalities into high-level (modeling, recognizing, planning and perception) layers, and low-level (sensing, interfacing and execute) layers. Individual system modules are integrated seamlessly to constitute the intelligent gripping system.
- Full Text:
- Date Issued: 2002
Methods for designing and optimizing fuzzy controllers
- Authors: Swartz, Andre Michael
- Date: 2000
- Subjects: Fuzzy sets , Fuzzy systems , Automatic control
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5412 , http://hdl.handle.net/10962/d1005226 , Fuzzy sets , Fuzzy systems , Automatic control
- Description: We start by discussing fuzzy sets and the algebra of fuzzy sets. We consider some properties of fuzzy modeling tools. This is followed by considering the Mamdani and Sugeno models for designing fuzzy controllers. Various methods for using sets of data for desining controllers are discussed. This is followed by a chapter illustrating the use of genetic algorithms in designing and optimizing fuzzy controllers.Finally we look at some previous applications of fuzzy control in telecommunication networks, and illustrate a simple application that was developed as part of the present work.
- Full Text:
- Date Issued: 2000