Impact of Added Passive Compliance On the Performance of Tip-Actuated Flexible Manipulators

Abstract With their inherent compliance, flexible manipulator systems (FMSs) are increasingly finding new applications, such as robotic surgeries requiring safe interaction with the environment. While force-controlled FMSs are desirable, an added passive, compliant element can enhance safety while preserving performance. This paper explores the effects of added compliance on tip-actuated FMSs. A detailed analysis compares the impacts of additional compliance, and comparisons are made with a baseline no-compliance case. It is observed that the series compliance provides added safety but with some compromise on performance and stability. In contrast, parallel compliance improves stability and performance without compromising safety in interaction. While similar insights have been well-understood in the context of rigid-link robots, it is interesting to observe that additional series compliance in tip-actuated flexible manipulators is undesirable, unlike for rigid-link robots.