Active Force Feedback in Real-life Industrial Robots

Abstract

Active force feedback in robots has been developed in the 1970s as an answer to the limitations of the passive solutions, like the RCC (Remote Center Compliance), offered as an add-on for peg-into-hole assembly operations. Generic solutions of force feedback and impedance control have been developed in laboratory environments, but their industrial use has been very limited ever since. This situation has recently changed and it becomes feasible now to provide off-the-shelf industrial robots with real-time force feedback capabilities. In the paper, two convincing case-studies of tasks with force control will be presented. One is the synchronisation of a brake press with a plate-handling robot for sheet metal bending applications. Synchronisation is assured in two ways: (i) through a geometric bending model, and (ii) through active force feedback. The second case study deals with forcecontrolled assembly of rotary compressors. Here passive RCC-like aids are compared with force-feedback solutions. In some critical cases, active force feedback is the only solution, while in other cases passive aids suffice.