Chaoyi Zhao

Research on Pressure Comfort of Sofa Based on Body Pressure Distribution and Subjective Experience

With the use of body pressure distribution measurement system, the pressure comfort of sofa was researched by the combination of user’s subjective experience evaluation and objective test. Through the different layers of soft sponge placed in sofa seat and backrest surfaces, the experimental conditions of different hardness were simulated. According to the evaluation results of user’s subjective experience about sofa comfort and the results of the physical pressure distribution collected objectively under different experimental conditions, the recommended ranges of most comfortable seat and backrest pressures were obtained, which have provided the reference and basis for the improvement and design of sofa.

Experimental Study on Thermal Comfort of Indoor Environment

In order to study the range of comfort environment parameters, subjective assessment and objective assessment are used in this research. The main purpose of this study is to determine the temperature and humidity range, acceptable temperature fluctuation, acceptable air flow rate and acceptable vertical air temperature difference under the thermal comfort environment in summer and winter. The thermal comfort environment should make the PMV between −0.5 and +0.5 which is recommended by international standard ISO7730. Following this principle, the comfort temperature ranges in summer and winter are determined respectively, comfort temperature range is 25–28 °C in summer and 22–25 °C in winter. Under the thermal comfort environment condition, the biggest acceptable temperature fluctuation is obtained and is 0.6 °C and the biggest acceptable air flow rate is 0.5 m/s in summer. In winter, if the vertical air temperature difference is higher than 3.2 °C, the subjects feel comfortable.

Research on Multi-factor Sofa Inclination Comfort Based on User Experience

In work and life, people pay more and more attention to the experience of using sofa products, and personal subjective using feeling has a pivotal role in the design of sofa products. In this paper, user’s subjective experience evaluation method was taken to research on the sofa seat and backrest inclination comfort based on three factors i.e. age, gender and different body sizes. Through the production of a test device with sofa seat and backrest inclination adjustable, the experimental conditions with different seat and backrest inclination were simulated. According to the results of user’s subjective experience evaluation on sofa comfort under different experimental conditions, the recommended scope of the most comfortable seat and backrest inclinations was obtained, which provides reference and basis for the improvement and design of sofa.

Research on the Environmental Thermal Comfort Based on Manikin

The subjective evaluation and objective test are the main methods to study the thermal comfort sensation of the environment. The Predicted mean votes (PMV) are calculated by thermal environment parameters obtained from the test points in general objective tests. However, the unstable factors of indoor environment make the description and prediction comprehensively and accurately impossible by the traditional methods. Through the physical and physiological characteristics of Chinese population in the Chinese adult human database, 50 percentile male adults’ three dimensional physical data was selected to establish the manikin model. Controlling strategy was formulated according to the heat balance equation and thermal manikin test system was designed to test the exchanged heat between human body and environment in an unsteady and heterogeneous environment. In the specific heat and humidity environment created by the laboratory, the predicted mean vote (PMV) of the current environment was −0.8 by the thermal manikin test system. At the same time, the subjective evaluation tests were conducted in the environment and the thermal sensation vote (TSV) was −0.65. The relative error was only 2.1% between the subjective evaluations and the objective test results of the manikin.

Head and Face Investigation of Chinese Adults and Analysis of Influencing Factors

The statistical data of head length, head width and head circumference acquired from the national ergonomic survey in 2014–2017 are analyzed and compared. It is found upon statistics that there is a significant difference between male and female. The head length and head circumference of male and female decrease with age. There is no significant difference in the head circumference of men and women in six regions. The rural population has no significant difference in the data with the secondary industry group, but has significant differences with the other three occupational groups.

Classifications of Body Size for Chinese Females in Three Areas

The female body size was collected from 3 regions including Northeast China, the Midwest region and region of the lower reaches of Yangtze River. The data includes 1452 samples and were divided into three age groups. And 36 anthropometric items are selected as the basic variables to conduct the principal component analysis for the determination of the main factors for the body shaping. The variance contribution rates of the first two factors for the three age groups were 72.557%, 68.953% and 65.145% respectively, which reflecting most of the information of the original variables. Among them, the first principal component factor is the trunk circumference factor; the second principal component is the height factor. Four indexes are selected to conduct K-means clustering analysis. The results of cluster analysis showed that when there were 6 body shapes, the classification results were clear and the number of people was relatively balanced.

Study of Body Shoulder Shaping for Chinese Females Based on 3-D Body Measurement

In this study, six main shoulder items for Chinese females were collected using 3D body scanner in 2015-2017. The Principal Component Analysis was used to determine the basic shoulder items for the shaping classification. Two principal components were extracted from 6 variables, which reflected most of the information of the original variables. The first principal component factor is the length factor; the second principal component is the angle factor. The most representative indexes are selected from the length factor and the angle factor by the correlation index maximum method, namely the shoulder width and the right shoulder oblique angle. The shoulder shaping clustering is based on the K- means clustering method. The clustering results shows that when the number of classes is 4, the proportion in the total number is 22.4%, 23.3%, 22.7% and 31.6% respectively, and the results are clear and the people in each class are relatively balanced.

Research on User Comfort of Intelligent Toilet Based on Ergonomics

An intelligent toilet was an upgrade product on the ordinary toilet, with all the functions of a common toilet combined with automatic flushing, seat ring heating, hip cleaning, female cleaning and drying with warm air and so on, which attracts the researchers’ interests recently. In the past, there are rarely few user comfort researches about intelligent toilet based on ergonomics. This study focuses on the research method of ergonomics to explore the comfort design of the intelligent toilet from user experience.

Study on the Moderate Thermal Environment Comfort Evaluation Using Thermal Manikin

A new manikin can be used to simulate heat transfer and thermal sensation of Chinese human body in moderate thermal environment. Local (t_eqlocal) and whole body equivalent temperature (t_eqwhole) had been measured in a uniform environment using it and compared with corresponding environmental temperatures. Objective/subjective evaluation trial was carried out in an air-conditioned climate chamber where 12 Chinese males sat to mark their sensation. By comparison it could be found: (1) after 100 min manikin thermodynamic state tended to become stable and t_eqwhole was 20.6 °C which approximately equaled to air temperature 20.7 °C in the uniform environment. Therefore, its measurement accuracy is verified to be very high. (2) in the chamber, PMV index measured by manikin was –0.8 which was close to subjective sensation vote (–0.917 ± 0.996), indicating that it is reasonable and credible to evaluate environment comfort by means of this manikin.

Research on Human Acceptability of Household Environment Temperature Fluctuation

In this paper, temperature fluctuation in the room which was tested in which environment is built by the domestic air conditioner Different air conditioning set temperature may cause different temperature fluctuation in each position. From the subjective assessment results it can be known that, under the thermal comfort environment condition, the biggest acceptable temperature fluctuation is obtained and is 0.6 °C in summer and 0.8 °C in winter. In summer working condition, temperature fluctuation in each test point is compared with the acceptable temperature fluctuation (0.6 °C) and then the satisfaction rate for each working condition can be obtained. The test results show that the highest satisfaction rate about temperature fluctuation is 94% when the indoor air temperature is about 26 °C. Air temperature higher or lower than 26 °C will reduce the satisfaction rate about temperature fluctuation. Working condition in the winter, using the same method, the satisfaction rate about temperature fluctuation for each working condition can be obtained, it is higher than the summer, it can reach to 90% in every working condition. It is because that tester wears a lot of clothes in winter, the clothes can reduce the body’s sensitivity to the environment temperature changes. Test results are matched well with subjective assessment. The research in this article can provide basis for thermal comfort evaluation of typical residential air conditioning room and also can guide the design of air condition system in order to ensure the thermal comfort of the room.