This paper reports on a six-axis vibration isolator for space applications. It is divided into three parts. The first part recalls the principles of active isolation and summarizes the main theoretical results for multiple-axis decentralized control based on force feedback. The second part discusses the technology and describes the evolution of the design over the five years of this project. The third part is devoted to the identification of the transmissibility matrix and the performance evaluation. Zero-gravity tests in parabolic flight are reported. The isolator is proved efficient in a frequency band between 5 Hz and 400 Hz, with a maximum attenuation of-40 dB between 50 Hz and 200 Hz.

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This aricle presents a novel, computer controlled, magneto-rheological (MR) brake actuated, muscular rehabilitation, and evaluation device. The first part discusses various MR brake architectures and compares them. Simple analytical formulae are developed for a set of figures of merit, which point out the role played by the various parameters. Based on this analysis, a prototype with a T-shaped rotor has been designed, built and integrated into a portable rehabilitation device. In the second part of the article, the various exercise modes of the device and its control are described. Finally, results validating the performances of the device for the pronation/supination motion of the wrist are shown.

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This article considers two devices based on a magnetorheological elastomer (MRE): an MRE isolator under a frequency-varying harmonic excitation and a MRE Dynamic Vibration Absorber (DVA) mounted on a frequency-varying structure under a random excitation. In the first case, it is shown that the commandability of the elastomer improves the reduction of the RMS value of the body displacement by 10%. In the second case, it is shown on a simple example that a MRE DVA, while not optimal, can reduce the stress in the structure about 50% better than a classical DVA when the mass of the structure changes 35%. This makes them suitable to avoid high stress in mass-varying structures, and delay some damage mechanisms like the emergence of cracks and fatigue.