Influence of dual vibrations on control of percussive hand-operated power tools – experimental investigations

This article presents the results of pioneer experimental research into the impact of whole body vibration (WBV) and hand arm vibration (HAV) with different amplitudes and frequencies on percussive tools which are controlled by hand. In these studies the human operator is considered as the active element of the control system. The quality of control executed by the participants of the tests was assessed by the typical parameters existing in control system engineering, such as rise time, settling time, overshoot and integral square error (ISE). The tests were performed on an especially built stand. Results are presented in the form of time histories of step reference force. Forces realized by the operator were statistically analysed and graphically presented. Local (HAV) vibration of tools and accompanying dynamic forces between the handle and the vibrating tool have a big influence on control of the tool. An increase in the frequency of the tools’ vibration increases the adjustment range. The influence of platform vibrations on the adjustment range is relatively small.