Haptics of Screwing and Unscrewing for Its Application in Smart Factories for Disassembly

摘要

Reconstruction of the skilled human sensations and design of related control system is important for robust control of the robots. We are developing an unscrewing robot with a comprehensive control system for the automated disassembly of electronic devices. Experiments involve screwing and unscrewing, and since humans typically have a broad range of screwing experiences and sensations throughout their lives, we conducted a series of experiments to find out these haptic patterns. Results show that people apply axial force to the screws to avoid screwdriver slippage (cam-outs), which is one of the key problems during screwing and unscrewing, and this axial force is proportional to the torque which is required for screwing. We have found that type of the screw head influences the amount of axial force applied. Using this knowledge an unscrewing robot for the smart disassembly factory RecyBot is being developed, and experiments confirm the optimality of the strategy used by humans. Finally, a methodology for robust unscrewing algorithm design is presented as a generalization of the findings. It can speed up the development of the screwing and unscrewing robots and tools.