ADAPTIVE-PASSIVE CONTROL SYSTEM FOR HAND-ARM PROTECTION TO VIBRATIONS

Abstract

One of the major causes of professional diseases is related to the vibrations transmitted to the hand-arm system. Several studies have been carried out in order to get thorough knowledge of the phenomenon and to identify ways for reducing the vibrations level. Since 2002 the 44 EC Directive came into force, which imposes to the hand-tool manufacturers additional requirements for their products so that the vibrations induced to the human body to be within the accepted limits. This paper proposes a new system for protection to vibrations, based on piezoelectric sensors for signal acquisition, a fuzzy controller for signal processing and a magneto-rheological fluid absorber. It uses the adaptive-passive control strategy, combining the feasibility features of the passive control with the adaptability of the active control, using relatively small energy sources outside the system. At the same time, the solution may be implemented at a significantly smaller cost as the active control system.