A simple systems approach is used to derive a basic framework for the effects of vibration on human operator performance. This framework is applied to an investigation of co-ordinated manual tracking during vibration. An experiment is described in which twelve subjects were required to perform zero order pursuit tracking of a quasi-random forcing function in a horizontal axis with freo-moving and spring centred control levers. The seated subjects were exposed to four conditions of vertical vibration by means cf a flat, hard seat. Each vibration condition consisted of a combination of three sinusoids (3, 5 and 8#xA0;Hz), each of equal acceleration amplitude (either 0, 0.25, 0.5 or 1 m/s2rms). Performance was measured in terms of information channel capacity and frequency dependent error. The frequency dependent measures wero used to distinguish error due to direct transmission of vibration to the control from that due to other sources. Vibration transmitted directly to the control caused only a small proportion of the tracking error in this system. With the control and display characteristics used in this experiment, subjects were better able to maintain tracking performance when isometric (force) cues were provided in the control. The results suggest that interference with kinaesthetic feedback mechanisms may be a principal means by which vibration degrades tracking performance.
展开▼
