University of Twente Student Theses
Ontwerp een gearticuleerde robot op schaal
Hout, Niek van den (2013) Ontwerp een gearticuleerde robot op schaal.
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Abstract: | The thesis which is described by this report is aimed at the design of an industrial robot on scale. The goal of this scale model is to provide a way to research if experts experience the control of industrial robots as convenient. Moreover the scale model will be applied at autonomous experiments. Industrial robot is a term which includes multiple types of robots with each different characteristics. These different types have been researched and classified. This led to the determination of one type that is most suitable for a scale design and corresponds with the starting points of this project. The type that was chosen is the articulated robot. This type appears often in industrial applications and is therefore representative for the product class of the industrial robot. Besides that the characteristics of the articulated robot are suited for a translation to a scale model thanks to the kinematic and aesthetic properties. After this choice the articulated robot was analysed more thoroughly. Amongst others a graphic overview of different models of the selected type was made. Based on this overview the aesthetic properties and proportions between the different parts could be characterized. The analysis of the articulated robot leads to guidelines that ensure the design to contain the right properties to make it an articulated robot. Furthermore it is of importance that the designed structure is able to withstand the applied forces. To this extend the load on the robotic arm was analysed which resulted in a mathematical model that can be used for calculating the required motor torque. Besides that the robot kinematics were studied because this is the foundation of robot control. From this study guidelines could be concluded for the position and orientation of the joints that lead to a simplified kinematical model. This simplification offers advantages for controlling the robot. The articulated robot consists of only articulated joints according to its characteristics. These joints are moved by electric motors that are placed at the centre of the joints. The movement properties and control depend strongly on the type of electric motor that is used. That is why several electric motors have been analysed to consider their properties opposed to the required application. This study shows that mainly two types of electric motors are suited for the required scale and movement. These are the stepper motor and the servomotor. Based on further research the servomotor was chosen, because this type has position feedback which results in a higher accuracy than can be achieved with the stepper motor. The knowledge resulting from the before described research of the articulated robot, mechanics and electric motors is processed into a list of requirements. This can be used to assess the final design and safeguard the goals and starting points of this thesis. The next step is the design process which is based on the results of the analysis phase. First the design freedoms of the kinematic structure are explored. These freedoms result in several conceptual designs that are compared to each other. The concept that offers the most flexibility in positioning the end-effector within the workspace is then chosen as a base for the further design. After determining the kinematic structure the design is aimed at a mechanical construction that is in accordance with the determined kinematic structure and can withstand the applied load. First existing scale models of robotic arms were studied to provide a starting point for the construction design. This study lead to the definition of an abstract base construction of a robot link. Based on this construction and by way of an iterative design process a link was designed that meets the demands of mechanical properties. The design is formed by a consideration between weight and stiffness and can be produced by way of conventional production methods. All five links are designed this same way and together form the entire construction of the industrial robot. Then a casing was designed to seal the construction and to realize a realistic appearance. The design of this casing based in both the aesthetic characteristics of the articulated robot and a personal influence that makes the robotic arm into a distinguishing product. The construction and casing combined form the total scale model of the articulated robot and with that the end product of this thesis. The robot has the kinematic, aesthetic and constructive properties of an articulated robot and can be produced with conventional production methods. Moreover the design is appropriate for performing milling tasks. This way the design meets the set requirements and achieves the objectives of this thesis. |
Item Type: | Essay (Bachelor) |
Faculty: | ET: Engineering Technology |
Subject: | 20 art studies |
Programme: | Industrial Design BSc (56955) |
Link to this item: | https://purl.utwente.nl/essays/63822 |
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