Energy management system for the diagnosis and control of an automatic guided vehicle
- Authors: Church, Stuart Michael
- Date: 2016
- Subjects: Automated guided vehicle systems , Mechatronics
- Language: English
- Type: Thesis , Masters , MEng
- Identifier: http://hdl.handle.net/10948/4798 , vital:20681
- Description: With the increase in electronic equipment implemented in various systems, as well as the increase in calculating power that these devices offer, designers are being empowered to make use of this power in real-time systems to diagnose and protect the systems themselves. This reasoning is too compounded by the focus on efficiency and safety in the design of complex systems, as well as the increasing expense and sensitivity of the electronic components themselves. With this in mind, this dissertation aims at developing a comprehensive measurement, control and reaction system for the electrical diagnosis and ultimately optimisation of complex electrical and electronic systems. This system will serve as a real-time diagnosis tool, which will enable the real-time diagnosis of various components in an electro-mechanical system, which can then be interpreted to determine the working state of the various components. Another sphere of this project will involve the accurate monitoring of the battery status as well as actively balancing the series connected batteries. The focus on the batteries will seek to prolong the life of the batteries, while being able to squeeze as much capacity out of them. The initial design and testing will be based on an AGV system implemented at VWSA, however a main goal throughout the design process will be modularity, i.e. the ease of implementation of this system in other systems. The key technologies used in the development of this system will still comprise of the components used in the original AGV, however new prototype components sourced from Microcare are used for the battery management system, while current sensors directly connected to the PLC’s analog input ports will be used for the active monitoring of currents distributed through the AGV.
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- Date Issued: 2016
Modular electric automatic guided vehicle suspension-drive unit
- Authors: Macfarlane, Alexander Blair Stuart , Van Niekerk, Theo
- Date: 2016
- Subjects: Autonomous vehicles , Sustainable design
- Language: English
- Type: Thesis , Masters , MEng
- Identifier: http://hdl.handle.net/10948/8220 , vital:25968
- Description: This report discusses the design, development, elevation and creation of a modular omni-directional suspension-drive train unit for use on 1000 kg automatic guided vehicle. The system included a semi-active suspension oleo strut system that can vary its dampening and ride height. The drive train system is capable of omni-directional motion through the use of separately driven mechanum wheels power by a 48 volt DC system.
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- Date Issued: 2016
Optimisation of glass scoring operation
- Authors: Bechoo, Durvesh Sookraj
- Date: 2016
- Subjects: Glass -- Mechanical properties , Glass manufacture
- Language: English
- Type: Thesis , Masters , MEng
- Identifier: http://hdl.handle.net/10948/9283 , vital:26559
- Description: The economic crisis and prior recession made a huge dent in many industries. Companies want a cheaper manufactured product with same quality to satisfy the customer in order be competitive yet profitable. Shatterprufe is a company that produces automotive glass. The company has a vast number of products and experience short production run lengths because of its order intake from customers. These short production run lengths require accurate setup to have a repeatable and stable process. An incorrect setup will produce a high scrap rate on production runs. Glass being very brittle and machining it incorrectly results in flaws, breakages or edge stresses that lead to latter process failures. The scoring operation of glass is key to achieve good edge quality to prevent such defects. The correct tools and machine parameters influence good edge quality during the setup procedure. Due to the process having many variables it is difficult to have a stable process and a repeatable stable process. This research will analyse the tool, parameters of the tool and machine parameters to achieve best edge quality and correlating these parameters that will lead to a repeatable stable process. An experimental analysis was conducted on 2.1mm and 2.5mm thick glass. These thicknesses are used predominantly at Shatterprufe automotive glass manufacturing company. The first sample and last sample was analysed during a production run. An average production run length is 36 pieces of glass. The edge quality was seen under a microscope and the fissure depth was measured. To achieve ideal edge quality, the fissure depth must be 15-20% deep of the glass thickness. A fissure is a crack propagated during the scoring of glass. A carbide wheel is used to score the glass. The carbide wheel parameters were varied being the wheel angle and wheel diameter. A 145 degree-4.1mm wheel, 145degree-5.6mm wheel and a 155 degree- 4.1mm wheel was used. The following relationships where observed being the wheel diameter and fissure depth. An increase in wheel diameter resulted in an increase in fissure depth but decreases the wheel life as the wheel becomes blunt. There was inconsistency on fissure depth with the larger diameter wheel. An increased in wheel angle from 145 degree to 155 degree promoted flaws in the glass. Larger wheel angles work better on glass thicknesses of 4-5mm as currently used in the Shatterprufe Struandale Company. An investigation on pressure variation in the pneumatic system was analysed using a pressure transmitter. The pressure transmitter measured the pressure per second versus the set pressure and recorded this data on a data logger. There was no pressure variation in the pneumatic system that can influence poor glass edge quality. A load cell analysis will investigate the physical applied pressure on the glass versus the set pressure. This analysis was to determine the relationship between set versus actual on the glass. It will indicate any mechanical fault. A mechanical fault could be a loose coupling or linkage that can influence the fissure depth. A direct proportional relationship was achieved between the set pressure versus the load cell readings. This indicates no mechanical fault on the system.
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- Date Issued: 2016
The development of boiler control models for the optimization of boiler efficiency
- Authors: Kellerman, Andre
- Date: 2016
- Subjects: Boilers Boiler-making industry , Steam-boilers Mechatronics Power electronics
- Language: English
- Type: Thesis , Masters , MEng
- Identifier: http://hdl.handle.net/10948/48014 , vital:40463
- Description: With Eskom’s fleet rapidly reaching end of life and maintenance outages becoming more frequent, it has become more critical to be able to determine transient effects of auxiliary losses and system responses due to instabilities. A low mono-nitrogen oxide (low-NOx) burner replacement project has recently been completed at Camden power station in Ermelo. It has thus deemed itself as a perfect candidate for a model which can be used to understand the new systems’ response during transient scenarios. The aim is to develop a boiler control model to be used for simulation of various process conditions and failure scenarios in order to predict the boiler plants’ behaviour and improve its availability. Research was done on common boiler control practices and modelling of boiler control. A theoretical boiler control model was developed based on the Camden power station’s control system specification. The computational model of the boiler control was implemented in Flownex® simulation environment, which was found to be particular useful for modelling industrial applications. A number of simulations with the computational model were performed and the results were compared against the historic plant data showing good correlation. In parallel, a thermo-fluid model of the boiler was developed using Flownex® by a Masters student at the University of Cape Town, which was then integrated with the control model. The combined Flownex model was used for simulation of the following important cases: a mill trip, a Forced Draught fan trip and load changes. The obtained results show good correlation with the real plant data, indicating that the developed computational model can be considered accurate for Camden’s particular type of boiler and its control. Hence, it is envisaged that the developed combined Flownex model can be applied for simulation of the boilers of the Camden power station.
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- Date Issued: 2016