Structural Analysis of 6R Robotic Arm. Comparison of Different Complexity Models

Abstract

Industrial manipulators are replacing manual workers in an increasing number of professions. Robots can nowadays be found in nearly all sectors of industry. Therefore, in an industry dominated by big companies (KUKA, ABB, FANUC), more smaller companies are trying to design their own robotic manipulators. Unfortunately, this is not an easy task – in addition to a well-equipped machine park, there is a need for scientific and research facilities, which small and medium companies cannot afford. The first step of structure analysis is to choose a proper kinematic and dynamic structure. In general, it is a very complex issue, and therefore there is doubt as to how simplified model can be adopted so that the obtained results are reliable. According to the authors' knowledge, there is currently no research available that would clearly indicate the validity of introducing such simplifications to the model. In this work, the most popular robot model was considered – a 6-axis manipulator with an open kinematic chain. The selected structure was based on a market analysis for small and medium-sized manipulators. In each subsequent step, additional details were added to the manipulator structure and the results were compared to each other. The conclusion of this work shows that increasing the complexity of the model is justified, but it only makes sense to a certain point. Further refinement significantly increases the time it takes to carry out the analysis, only slightly affecting the accuracy of the results.