Construction And Research Of Ship Personnel Emergency Evacuation Model

Some differences between the personnel evacuation on ship and that on land are identified.In the event of a ship accident,the deck tilt not only affects the velocity at which persons evaluate on ship,but also causes persons to bent-over walking and crawling in addition to walking.The previous evacuation simulation software doesn’t support the simulation of these evacuation modes.In an accident,the alarm effect will influence personnel response to evacuation.Common methods for the assessment of ship alarm effect can differentiate which feature changes are valid for the alarm effect,but such methods don’t support quantitative assessment and consequently cannot differentiate the extent of influence of valid feature changes on the alarm.In this regard,this thesis focuses on the quantitative assessment model of ship alarm effect and the simulation model of ship evacuation with the main works described below:Since the common binomial test and Likert scale cannot differentiate the intensity of impact of the alarm feature change on the evacuation response of persons on ship,a quantitative assessment model of the impact of alarm on the evacuation response of ship personnel is proposed based on the affordance theory.Then,the commonly used ship alarms are functional classified and the corresponding quantitative assessment steps are designed.Finally,a method for screening logical error data out of the experimental results was put forward based on the affordance theory,with the validity of data improved.Compared with binomial test and Likert scale,the results show that: the quantitative assessment model of alarm effect based on the affordance theory not only avoids the deficiency that the binomial test cannot identify the threshold of the alarm feature on the alarm effect,but also screens out logical error data and quantitatively analyzes the impact resulting from alarm feature changes.The alarm effect is improved 3.23 times when the sound pressure is increased from 60 db to75 db,and 1.11 times when the sound pressure is increased from 75 db to 90 db,and the threshold value of sound pressure on alarm effect is 75 db.The alarm effect in the scenario of adding recorded voice alarm is found the most intense,which can be viewed as the best option for enhancement of alarm effect.Given the fact that the common evacuation simulation software(e.g.: AENEAS and evi)do not support the simulation of the evacuation modes(including bent-over walking and crawling)other than normal walking caused by the deck tilting,the actual evacuation time is often several times of the simulation time,and the conventional fine grid velocity algorithm restraints the description of collision volume differences.To solve these problems,a speed algorithm using fixed grid to judge the moving permission is proposed,an algorithm using movable directed line segments composed of adjacent nodes to denote the collision volumes in the scenarios of bent-over walking and crawling,and an algorithm for differentiating body height differences are put forward,which can be applied for the change-over of different evacuation modes and the determination of the evacuation mode available for use.The distance accumulation lattice gas model that integrates these algorithms would realize the ship evacuation simulation in respect of walking,bent-over walking and crawling.The reliability of the model is validated by multiple modes of evacuation experiment trials in the IMO suggested test scenarios.According to the experiment and simulation results,the evacuation time of the walking simulation derived from the distance accumulation lattice gas model is longer than that of the experiment results;the evacuation time of the bent-over walking and crawling simulation is shorter than that of the experiment results,in 109%,95% and 88% of the experiment results respectively.Counter-flow is a customary practice during the personnel evacuation on ship.Given the fact that the counter-flow weight algorithm previously used in the evacuation simulation model will lead to some deviation from the actual behavior: the persons on one direction assigned with a lower weight will retreat,while those on the other direction assigned with a higher weight will go first,a new moving algorithm of evacuation simulation model is proposed to introduce the main moving direction,thereby determining the situation of counter-flow during the ship evacuation.In addition,an intelligent avoidance algorithm is proposed as a substitute for the prior weight algorithm to process the scenario of counter-flow.The algorithm of counter-flow effect on speed is also used to correct the personnel speed,to the extent that the simulation of counter-flow during the ship evacuation would be closer to reality.The counter-flow experiment demonstrates that the intelligent counter-flow avoidance algorithm tends to be more realistic and reliable compared to the counter-flow weight algorithm.The function and performance of the evacuation simulation model is tested under the IMO suggested test scenarios.According to the experiment and simulation results,the evacuation time derived from the intelligent counter-flow avoidance algorithm is 109% of the experiment results,which is believed to be more realistic than the counter-flow weight algorithm(124% of the experiment results);an increase of the persons in counter-flow would lead to longer evacuation time.The ship alarm evacuation model based on the affordance theory can screen the logic error data out of the assessment results,and allow for the quantitative assessment of the effect of the customized ship alarm in particular site and specific noise environment.With the assessment steps modified,the proposed model can work as a test procedure for alarming,answering and displaying of other equipment in cabin.The distance accumulation lattice gas model can be applied to simulate different evacuation modes and simulate the scenario of ship counter-flow in a more realistic way.It can predict the recurring sites of congestion and counter-flow,help crew members in directing the evacuation work,and predict evacuation behaviors of the persons choosing different evacuation modes,in order to assist the rescue at sea,reproduce the scenarios of ship evacuation accident and find out the cause of such accident.In addition,the data obtained from model evacuation simulation can be helpful for the design and improvement of ship structure.