Abstract
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.