Three-dimensional cellular magnetorheological elastomer absorber for suppressing time-varying chatter in robotic milling

Robotic machining technology plays a crucial role in the manufacturing of large components. However, the time-varying chatter phenomenon is a major obstacle to improving machining efficiency. Effective vibration suppression devices for robots must cope with chatter that changes in both direction and frequency, as well as maintain reliability during large variations in robot poses. This paper introduces a novel three-dimensional cellular magnetorheological elastomer (C-MRE) absorber. The absorber consists of meshed magnetorheological elastomers (MREs) and magnetically conductive spheres embedded therein in the form of a cellular distribution, allowing it to operate in any direction within three-dimensional space, and maintaining its ability during any rotation. A dynamics model of the C-MRE absorber is established, and its natural frequencies are simulated for various parameter combinations, revealing design principles or guidelines for selecting absorber parameters. The operating frequency band of the C-MRE absorber can be adjusted by controlling the current, to match the time-varying frequency of chatter. Experiments show that the developed C-MRE absorber prototype can achieve a maximum suppression effect of 87% for various robot modes. Additionally, it continues to function normally after rotation, with an operational bandwidth of approximately 10-30 Hz.