The use of industrial robots are increasing in areas such as food, consumer goods, wood, plastics and electronics, but is still mostly concentrated in the automotive industry. A problem is that workstations in smaller and medium sized companies that produce small batches of products don’t get productive enough by having a permanently placed industrial robot. A solution could be a lightweight robot that is adaptable to the product need. It would have lower moving mass that will reduce the power need and result in “greener” robotics.
The aim of this project has been to develop a concept of a lightweight robot using lightweight materials such as aluminum and carbon fiber together with a newly developed servo actuator prototype.
The main problem was how to place the servo actuators, to create a wrist that would be thin and durable, while keeping performance as an ABB IRB 2600 robotic wrist. The wrist also needs to be constructed for cabling to run through on the inside. It is expensive to change cables and therefore the designing to reduce the friction on cable, is crucial to increase time between maintenance.
A concept generation was performed based on the function analysis, the QFD and the specifications of requirements. From the concept generation, twenty-four sustainable concepts divided into four groups (representing an individual part of the whole concept) were evaluated. From the evaluations a few concepts from each group was chosen to do a more thorough investigation on. The best concepts from each group were then merged into a final concept that was taken for further development.
The chosen concept was more detailed designed, which seemingly did not fulfill the requirements as good as I had hoped, but during the further development a small change in the concept helped with fulfilling those demands. To evaluate possible component failure, an FMEA was established.
The chosen concept of this study could fulfill the problems of designing a lightweight arm while keeping the same performance as the IRB 2600 robotic arm. This was realized by using the newly developed servo actuator together with the design that resulted from the implemented design process. The chosen concept has a thin wrist, with smooth passages for cables to run through keeping costs down. The robotic wrist needs more thorough analysis and testing, and I recommend that a mechanical prototype is made to test the movements of the robot.
Source: Mälardalen University
Author: Jaber, André