Development of variable RCC and its application

Most work on compliance or force control schemes in doing precision assembly has been insufficient to provide satisfactory performance, and therefore applications to manufacturing have been few. The remote centre compliance (RCC) device is the most famous of the passively compliant devices and has been already used in some operations. However, it is well known that the RCC has some limitations in flexible precision assembly automation: its characteristics (such as the position of remote compliance center and compliance at the point) are not variable. The device has not in fact been improved since its invention 20 years ago. To confer more flexibility to a robotic assembly line, we developed a cost-effective, compact, and lightweight variable RCC (VRCC). The invention of a simple but unique mechanism enabled the fabrication of the variable RCC. The device eliminates the need for an additional complex electrical control system or theory to cope with variation. Moreover, we have verified that a single VRCC duplicates the performance of a wide range of commercially available fixed-type RCCs.