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Objective To resolve the problems of comprehensive evaluation on pilot's situation cognition basing on studying the mission situation. Methods The model of fuzzy comprehensive evaluation on pilots' situation cognitive was established on the basis of researches on concepts and methods of environmental quality evaluation in environment science.Results On the basis of theoretical consideration and analysis of experiments, the state of pilot's situation cognition was revealed preliminarily.Conclusion It is showed that the fuzzy comprehensive evaluation method on pilot's situation cognition can provide real and complete flight cognitive information. It is reliable basis for pilot's efficacy of training and flight safety.
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Objective To provide a more accurate calculation method for design of condensing heat exchanger (CHX) through an in depth discussion about working conditions of the CHX commonly used in temperature and humidity control system of manned spacecraft.Methods With difference of the simplified configuration of CHX,a mathematical model was given.Specifically,the log-mean temperature difference (LMTD) method was used in dry conditions,while in wet conditions mass and energy conservation equations were used.The set of equations of the model were solved by using the shooting method provided by Matlab/Simulink program.Results The results of working conditions and the performance of heat transfer and dehumidification of CHX were determined.Analysis showed that the simulation model could evaluate performance of the CHX in different work conditions reasonably and the results were close to the physical phenomenon.Conclusion The simulation models are of significance for design and optimization of CHX both in manned spacecraft temperature and humidity control system and in aircraft environmental control system.
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With the development of space exploration,high performance extravehicular activity(EVA) space suit portable life support system(PLSS) is expected.In this paper,the research progress of PLSS for EVA is introduced.The techniques of CO2 removal system and H2O removal system are key parts of PLSS.These concepts are compared and analyzed.Prospects of development of PLSS are proposed.Those mature,reliable techniques should be adopted for our country.Regenerative PLSS facilities should be investigated simultaneously.
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Objective To establish a complete heat transfer boundary condition model in a cockpit including the inner wall heat transfer boundary condition and the air supply heat transfer boundary condition of the air distribution system. Methods The temperature field in the cockpit was carried out unmerical caculation with above model and the traditional method which was assumed uniform heat flux through walls and flow flux out of each air supply hole individually.An experiment was carried out to prove the caculation accuracy of both methods. Results The comparison between calculation and experiment results shows that the temperature field calculation accuracy of this model was much higher than traditional method’s.This model could indicate the unevenness and the asymmetry of the heat transfer through walls and the air temperature out of air supply holes of air distribution system. Conclusion This model is reasonable and has a good engineering application value.
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Objective To study the characteristics of pointing movement time for targets with different position in front of human body,to detect the effects of targets location on pointing movement time.Methods A pointing movement experiment of human arm was designed and carried out.By the statistic analysis of the experimental data,the relationship between pointing movement time and target position was discussed.Results It was shown that the starting point position and target position extremely affected the pointing movement time.Conclusion When a right-handed person touches the different targets,both the direction to target and the starting point position(target-circle location) would affect the pointing movement time extremely.When the position of the starting point changed by horizontal or vertical,the pointing movement time is more changeful by horizontal than that by vertical.To compare the pointing movement time for each target on a target-circle,the pointing movement time for right-upper target is the shortest.When the starting point is located on the right side of human body,all pointing movement time of that target-circle is the shortest.
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Objective To establish a system to evaluate the mental workload on visual display interface in airplane cockpit after synthesizing three kinds of mental workload assessment techniques,i.e.main task measure method,physiology measure method and subjective evaluate method.Methods The evaluation indices of every kind of assessment techniques was defined,and the amount of each index through experiment and subjective inquiry was gained,weighted average was calculated and a quantification evaluation value of each kind of evaluation methods was got.At last,with weighted calculation of above three evaluation values,the evaluation value of mental workload on visual display interface in airplane cockpit was obtained.Results In M kinds of different designs of visual display interface in airplane cockpit,the synthetic evaluation value of one design was the smallest and the mental workload of this design was the smallest.The design of the smallest mental workload was chosen prior as the final scheme of visual display interface in airplane cockpit.Conclusion The evaluation system is combined with present main evaluation methods of mental workload and utilizes their advantages.The evaluating result can be quantified more directly and clearly.With this evaluation system,the mental workload can be evaluated during the design of visual display interface of airplane cockpit and the best scheme can be confirmed.
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Objective To study pointing movement characteristics and ergonomics when human upper limb touches different targets on the front board. Methods An experiment was designed, in which the data of motion duration, peak velocity, trajectory length and peak power at shoulder and elbow joint were collected. Results By analysis of the experimental results, the pointing movement characteristics among the different regions on the front board were disclosed preliminarily. Conclusion When a right-handed person touches a target on the front board, the pointing movement ergonomics on left-upper region is the best, while that on right-lower region is the worst.
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Objective To search for perfect and logical evaluation indexes of range of motion of manual performance and maximal voluntary range of motion. Methods From mechanism of hand movement and characteristics of manual action,some relative comprehensive evaluation indexes on range of motion of manual performance were provided.Twenty six undergraduates (14 male and 12 female)participated in the test for 16 indexes. Results The maximal voluntary range of motion of thumb,four fingers and wrist were obtained. Conclusion The results can provide foundation for ergonomics design of spacesuit gloves.
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Objective To find a biomechanical evaluation methods of manual performance fatigue,for providing the feasible methods for the hand fatigue of spacesuit glove.Method Twelve females and forteen males in two groups served as the subjects and participated in the experiments of changeless force fatigue,including gripping,pinching and screwing,and took part in the nondimensional force fatigue.Result Manual performance fatigue could be fully evaluated based on gripping,pinching and screwing.The nondimensional force fatigue had widely applied ranges and well veracity.The combination of nondimensional subjective and objective evaluations was the optimal fatigue evaluation method.Conclusion The results can provide the feasible methods for performance evaluation of spacesuit glove system.
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Objective To build an index system for ergonomic evaluation of cockpit display.Method The modified Delphi method was proposed to build the index system.Firstly,on the basis of systematic,in-depth analysis and integration of the related information such as military standards,norms and technical productions both domestic and abroad,an index system for cockpit display ergonomic evaluation was primarily built.Then,23 fighter pilots were referred twice as the specialized consultants upon preliminary index system with the modified Delphi method.Finally,the comements of the specialized consultants were statistically analyzed.Result Based on the two times of information from the specialized consultants,the indexes that could cause more impact on pilots' efficiency were selected.Conclusion Modified Delphi method characterized with referring and synthesizing experimental results from experts is scientific and operatable.
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One of the key techniques in the research of human motion analysis is the reconstruction of human spatial motion utilizing the evaluation of the anatomic points positions that can uniquely define the position of all anatomical segments. Upon the bases of direct linear transform and human biomechanical model, the method to reconstruct an image sequence shot by a stationary camera was described. The result of the reconstruction process was a set of data that is kinematically consistent with the biomechanical model used. A new method to calibrate camera was developed which can be completed in any world coordination system according to the practical situation. A practical motion was selected as the investigated subject. The predicting and experimental results were in good agreement. The benefits and shortcoming of the methodology were discussed.
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Humans , Biomechanical Phenomena , Gait , Physiology , Image Processing, Computer-Assisted , Methods , Imaging, Three-Dimensional , Methods , Models, Biological , Motion , Movement , Physiology , PhotographyABSTRACT
Objective This paper deals with the problem of human movement characteristics of target acquisition. Method A hypothetical model was posed by using experimental data. Result The conception of final target size was put forward, an equation for calculating the movement time of target acquisition was obtained, and a new definition of index of difficulty was given. Conclusion Analysis of experimental data showed that this equation could give a better description of target acquisition in a wide range.