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In the present study, a modified multi-grid fire evacuation model (MG-Fire-Evac) was devised to study the influence of fire-related phenomena such as toxic smoke and heat on occupant evacuating from a burning building. The degree of injury suffered by the occupants is quantified in terms of “health points” (HPs) in the model. When a person’s HP is less than 0.5 or 0.8, he or she is regarded as having succumbed to the fire (becoming a fatality or serious injury). A parameter is defined to represent the degree of influence of the fire on the occupants’ movement, which is used to predict which of three possible kinds of egress is attempted. To decrease the degree of error in the data transferred between the fire simulation and egress model, a finer grid resolution is adopted in the new model. For the scenario examined, simulation results demonstrate that a higher fire load, longer pre-movement time, or narrower exit would all lead to more serious occupant injury in the event of a fire. Based on the MG-Fire-Evac model, a new building fire risk procedure is presented whereby it is possible to predict the death toll and number of serious injuries and to quantitatively evaluate evacuation plans. Compared to the conventional method, the new method is stricter and more scientific. The model and method presented herein will be useful for application to the performance-based design, assessment, and management of building fire safety.

This study presents an evacuation experiment to test individual behavior in an interactive virtual environment. A total of 68 test scenarios were established, and 122 participants were recruited to take part in all the test scenarios. The results show that individual attributes, such as sex, education background, age, and evacuation experience, have a correlation with the participants’ ability of escaping in the virtual evacuation environment. Specifically, younger men with higher education level and evacuation experience may have a better ability of escaping. The comparison of the evacuation paths, directions, and times among 8 scenarios with different sets reveals that people prefer to select the shortest route, but keep away from the fire source as much as possible if a fire happens. On the other hand, other people compete with the individual for the available evacuation resources, but when the exit location is unknown, other people may help individuals find the exit. In addition, the visibility decreases in case of fire, which is the most difficult condition for escaping with the longest movement distance and most evacuation time. This study will be useful to understand the human behavior and movement characteristics during evacuation by using a cheap and safe method.

Study on civil aircraft emergency evacuation process by using of computer model is an effective way to validate and improve the evacuation performance of aircraft. In this paper, based on the characteristics of the aircraft structure and personnel evacuation, a finer-grid civil aircraft evacuation model (FGCAEM) is built. In this model, the effect of seat area, others and fire products on escape process is considered. Simulations reproduce typical characteristics of aircraft evacuation, such as the movement synchronization between adjacent pedestrians, route choice and so on. It is indicated that evacuation efficiency will be reduced significantly in case of fire, especially in the last period of the evacuation process. Results will be helpful for the design of security auxiliary equipment of airplane and promoting management procedure to emergency case.

In recent years, the research on group movement has been drew pedestrian and evacuation dynamicists’ attention. In this paper, we explored to build a group model in a simple way. The group model considered two drift parameters, D and d. Thereinto, D expresses the destination’s attraction and d stands for group leader’s attraction and d is simplified to direct towards the group leader. Meantime, a method of generating groups is proposed. The simulation results show that with the increase of group size, the negative effect of group on crowd becomes greater. And group walking has more obvious effect on group owning large velocity. Besides the increase of group attraction intensity makes the negative effect distinct. In addition, it is found that with the increase of group disperse degree, the negative impact of group walking becomes obvious. What’s more, the effect of group disperse degree will not increase without limitation. The findings in this paper help researchers understand the impact of the presence of groups on crowd.

For the spraying mobile robot working in greenhouse, due to the inconsistency of drive motors and the rough walking surface, it is easy to track off. For the liquidity of pesticide, the load always changes even the speed jumps. Because of these uncertainties, external disturbances and the difficulty of constructing the system dynamic model, it is hard to implement the trajectory tracking control of the spraying mobile robot steadily, precisely and quickly. In order to solve the problem, a smooth sliding mode trajectory tracking control method is proposed based on the distribute control strategy for each branch. Moreover, its stability is proved using the Lyapunov function. The simulation results show that the proposed method can track the reference trajectories precisely, quickly and steadily under the strong white noise. The chattering phenomenon of the control law is restrained compared to the conventional sliding mode control. The trajectory tracking performance is better than that of the fuzzy control. The designed method is easy to realize and doesn’t need to construct the precise mathematical model, so, it affords an economical and convenient control method for solving the trajectory tracking problem of the greenhouse spraying mobile robot under various uncertain interferences. DOI: http://dx.doi.org/10.11591/telkomnika.v11i2.1988