Research On Human Factor Comfort Texting Device Of Wrist Wearable Products Based On Wrist Anthropometry

Human factor comfort testing and improvement of wearable products is an important part of wearable product design,especially for wrist-worn products that need to be worn all day.This research depicts a mechanical and thermal comfort index measurement device design for wrist-worn wearable product for Chinese users.There are three innovations in this research: 1.The wrist product mechanical comfort and thermal comfort index measuring device studied in this subject can test the product’s comfort by measuring the pressure,pressure distribution and temperature changes before and after wearing the wrist product.This device can replace the human factor test of product,and effectively save the labor cost and time cost of the human test.Furthermore,the test result of this device is more objective and accurate when human’s cognition of their own physiological changes is vague and fluctuating.2.Anthropometry is applied in the design of the device,so that the comfort index measuring device conforms to the measurement size of the Chinese and is representative.It can test the compatibility of wrist products with Chinese wrists,and whether the sultry feeling caused by wearing on the wrists of Chinese users is low,which overcomes the problem that participants of tests are difficult to have representativeness of the size characteristics of the target user group.3.In the device for measuring force comfort index,the wrist models are constructed in layers,and layered wrist models with different material properties are produced,which can simulate the human wrist from the aspect of mechanical properties.In the device for measuring thermal comfort index,a body-warming wrist model with temperature gradient distribution is produced,which can simulate the human wrist from the aspect of heat exchange with the environment.This two kinds of wrist models simulate the mechanical and thermal physiological characteristics of the human wrist respectively.This research uses multidisciplinary knowledge to carry out innovative exploration and research in the field of human factors engineering,which is the human factors comfort test device,and provides new research ideas for the evaluation and improvement of human factors engineering of products.The mechanical comfort index measurement device is composed of a layered wrist model and a pressure sensing system.The size characteristics of the layered wrist model is based on the wrist dimensions of Chinese.This model could simulate the structure and mechanical properties of human wrists.The thermal comfort index measurement device is composed of a thermal wrist model and a temperature sensing system.The size characteristics of the thermal wrist model is based on the wrist dimensions of Chinese.This model can simulate the heat exchange between a human wrist and the external environment.This device can calculate the mechanical and thermal comfort score of wrist products by measuring the pressure when wearing a wrist product,calculating its pressure distribution,and measuring the temperature rise of the wearing area before and after wearing the wrist product.Firstly,in order to make the designed device conform to the characteristic size of Chinese people’s wrists,and to represent the human comfort of Chinese users when testing the products,this research firstly conducted a wrist measurement study on a large sample of Chinese people.937 3D wrist models were collected by 3D scanning method,6 Chinese wrist eigenvalue data were extracted,data analysis was carried out,and the model and data analysis results were fitted to 5%,25%,50%,75%,95%percentile Chinese representative 3D wrist mode by algorithm.Secondly,a mechanical comfort index measurement device is developed.Based on wrist anatomy research,the representative wrist model is divided into five levels of bone,muscle,tendon,soft tissue,and skin.Using materials with different material properties,through pouring and demolding processes,the wrist model is made into a layered wrist model that conforms to the size characteristics of Chinese wrists and can simulate the structure and mechanical properties of real wrists to a certain extent.An eight-channel pressure measurement system for the layered wrist model is configure,so that it can obtain the product wearing pressure by measuring the pressure at 8 points under the wearing area when wearing the wrist product and calculating the pressure measurement variance of the 8 points.A thermal comfort index measurement device is developed.Based on the research on the thermal regulation mechanism of the wrist,a heating wire is wound on the surface of the representative wrist model and epoxy resin is coated,and a constant temperature heater is connected to the model for constant temperature heating.The wrist model is made into a warm-body model that conforms to the size characteristics of the Chinese wrist and can simulate the heat exchange between the real wrist and the external environment to a certain extent.A thermal infrared camera is configured for the warm-up wrist model,so that it can obtain the thermal comfort index of the temperature change before and after wearing the product by measuring the temperature rise value at two points below the wearing area when wearing the wrist product.Finally,the mechanical and thermal comfort of the four wrist-worn products were evaluated by using the layered wrist mold mechanical comfort measurement device and the warm-body wrist mold thermal comfort measurement device respectively.The measurement experiment of wearing comfort index of real person and device was carried out respectively.While applying the device designed in this subject,the feasibility of the device for wrist product comfort test was tested.Through data analysis,the mechanical comfort and thermal comfort of 4 wrist-worn products were compared.At the same time,the experimental results show that the comfort evaluation device studied in this topic can objectively and effectively predict the mechanical comfort and thermal comfort scores of the product by measuring the pressure,pressure distribution and temperature changes when wearing the wrist product,so as to evaluate the force comfort and thermal comfort of the product and guide the improved design of the product.