Finger Design Automation for Industrial Robots : A Generic and Agile Approach

Sammanfattning: ROBOT fingers play a crucial role in the success and performance of workcells, as fingers are the only interfaces that connect the robot to the physical working environment. Fingers are responsible for grasping and manipulating workpieces without dropping or damaging them. Designing industrial robot fingers to accomplish assigned tasks is therefore tremendously complex and requires high skills in robotics and designing at the same time.Today, there is a trend toward products with short lifecycles and, as a result, many robot industries have focused on enhancing the competitiveness of robotic automation in the agile market. SARAFun and Factory-in-a-day are two large European Commission projects which are formed to enable a non-expert user to integrate a robot system for an assembly task in one single day. Currently, fingers of industrial grippers (e.g. parallel- jaw) are designed manually, a process that requires several exhaustive and time- consuming trial and error iterations even for highly skilled specialists. The average iteration time is about three to four working days and the total time for designing fingers can amount to around two weeks depending on the complexity requirements.The present iterative procedure of manual finger design is unable to fulfil the demands of ‘‘burst’’ production (i.e. ramp up to full volume in a very short time, run production for 3–12 months, and then change to produce a new product). Finger design automation has therefore been increasingly attracting the attention of the robot industry. However, very few researchers have studied finger design automation and unfortunately no one has validated the proposed approaches with a generic experimental method.This research therefore proposes the generic optimized finger design (GOFD) framework in order to automate the design process of robotic fingers. The framework is optimized to reduce the design process time while maintaining high reliability and performance of the fingers. The functionality and general applicability of the framework is examined in various case studies and applications with a diverse range of workpieces. In order to be able to benchmark the functionality of robotic fingers, an experimental method is also developed to measure the stability and performance of the fingers in industrial practice. The proposed experimental method is employed to evaluate the functionality of the GOFD fingers and compare it with that of other fingers. Results are comprehensively analysed and the strengths and weaknesses of each method are highlighted. This thesis thus presents a design automation processes that automates the design procedure for robotic fingers, together with an experimental method to compare the performance of different finger designs. The introduced GOFD method can help robot industries comply with the trending agile market. Moreover, scholars who are inexpert in robotics may benefit from utilizing GOFD in their research to generate functional fingers.