Effects of vibration and low-frequency motions on passengers and crew

1. 100 80 60 Probability (%) 40 20 0 0.1 0.16 0.25 0.4 0.63 1.0 1.6 2.0 Acceleration (ms-2 r.m.s.) Effects of vibration and low-frequency motions on passengers and crew The Human Factors Research Unit conducts basic and applied research in human responses to vibration, including health effects, discomfort, performance, biodynamics, seating dynamics and motion sickness. Dependence of motion sickness on low-frequency motions Crew Response to Motions of an Offshore Oil Production and Storage Vessel • Using unique simulators, laboratory experimental research has explored effects of motion and vibration on human comfort, performance, and health. • Motion sickness studies have included: • Fore-and-aft oscillation • Lateral oscillation • Roll oscillation • Combined lateral and roll oscillation • Combined fore-and-aft and pitch oscillation • Vertical oscillation • Rotation of the visual field • Effects of motions on crew members of an FPSO (floating production and storage offshore) were studied over a five-month period • Vessel motions were continuously monitored during winter months (October to March) • A questionnaire survey in the form of a “daily diary” was completed by crew members for each day offshore Task performance problems Tiredness and sleep problems Model for predicting illness ratings (IR): The model produces useful predictions of the accumulated illness ratings reported by persons exposed to combinations of lateral oscillation, roll oscillation and vertical oscillation in the ISVR laboratory studies • Supported by: • EC Project no. G3RD-CT-2002-00809A Rational Approach for Reduction of Motion Sickness & Improvement of Passenger Comfort & Safety in Sea Transportation (COMPASS) • Conclusions • Problems with physical tasks involving balancing, moving and carrying were most strongly associated with motion, followed by sleep problems • Physical and mental tiredness, and cognitive aspects of task performance, were significantly associated with motions, but correlations were less strong than with physical tasks • There was a rapid increase in great or severe problems (ratings of 3 or 4), when the daily average vertical acceleration increased above 0.6 ms-2 r.m.s. Effects of Deck Motions on Postural Stability • Independent variables • Magnitude • Frequency • Direction of the oscillatory motion Supported by an offshore oil production company: Haward B, Lewis C, Griffin, M (2009) Motions and crew responses on an offshore oil production and storage vessel. Applied Ergonomics 40, 904-914. • Dependent variables • Subjective measurements (estimated probability of losing balance) • Objective measurements (forces applied by feet during gait) Development of standards and guides for evaluation of human response to shipboard whole-body vibration Comparison of 1/3 octave band spectra of 3-axis deck accelerations on a 36-m catamaran with Lloyds and ABS vibration limits for high-speed craft. f = 0.8 Hz, a = 0.5 ms-2 r.m.s Treadmill mounted on 6-axis simulator Time-history of perturbation • At a specific frequency, estimated probability of losing balance increases as the perturbation magnitude increases • At a specific acceleration, fall probability decreases with increasing frequency • At a specific velocity, fall probability is almost independent of frequency Seat and deck-mounted accelerometers • Collaborations: • American Bureau of Shipping • Whole-body vibration class guides for crew habitability and passenger comfort on ships, yachts and HSCs • Maritime and Coastguard Agency • Codes of practice for noise and vibration in ships • European Commission • Non-binding guide to good practice for implementing Directive 2002/44/EC on the minimum health and safety requirements regarding the exposure of workers to the risks arising from physical agents (VIBGUIDE) • Risks of Occupational Vibration Exposures (VIBRISKS) • A Rational Approach for Reduction of Motion Sickness & Improvement of Passenger Comfort & Safety in Sea Transportation (COMPASS) • Evaluation and Improvement of Suspension Seat Vibration Isolation Performance (VIBSEAT) Subjective Measurements − Estimated probability of losing balance Supported by: Société Nationale des Chemins de fer Français (SNCF) Human Factors Research Unit tel: 023 8059 2277 e-mail: M.J.Griffin@soton.ac.uk www.humanvibration.com www.southampton.ac.uk