M.Ing. / Parts feeding devices or feeders are used in automated assembly systems to deliver correctly oriented parts to the assembly station workhead. These devices play an important operational role since feeding is one of the major operations involved in an automated assembly process. However they account for much of the cost of an automated assembly system because most of the engineering time spent to develop such a system is used to devise a means of feeding the components in the correct orientation for the assembly process. This thesis describes the implementation of an integrated and computer controlled feeding and transfer system. The system consists of a vibratory bowl feeder for selecting, orienting and feeding parts and a flat conveyor belt for transferring parts to a prescribed location. The work focusses mainly on the design and analysis of the bowl feeder, on the mechanical and information interfacing aspects of the integration problem and on the control of the system. Sensing and electronic control circuits were also built to complete the system. The system implemented is to be integrated at a later stage with an industrial robot for handling purposes. Therefore, some issues related to the handling of parts from the conveyor belt by the robot are also discussed. Experimental results show that the recommendable operating frequency for the vibratory feeder is close to the value predicted by theoretical analysis. Several concurrent activities with critical time constraints and different periods were involved in the system, making the control more difficult due to the limited control capabilities of Visual basic, an easy to learn programming language used to implement the control program and the relatively slow speed of the computer used Nevertheless, it was observed that for feed rates close to 3 parts/min, the program developed performs well regarding the random control of the flow rate of parts on the conveyor, parts position and speed profiles obtained compare satisfactorily with the corresponding theoretical profiles. Recommendations for the integration of the robot to the system are made.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:uj/uj:10279 |
| Date | 12 September 2012 |
| Creators | Mangala, Ngongo Katembo |
| Source Sets | South African National ETD Portal |
| Detected Language | English |
| Type | Thesis |
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