## 3 Results and Discussion
### Discussion  
In this study, to libraryize 3 DP-pHRI into various sizes and shapes, the method of subdividing the size section and the method of generating the average human model for each section was used. There are three methods for subdividing the size section: the grid method, the clustering method, and the optimization method. The grid method, which is most commonly used in the field of anthropometry, was used as the method for subdividing the size section. There are three methods of generating an average human body model: wireframe modeling, morphing modeling, and template model fitting transformation. The wireframe modeling, which is advantageous for averaging work that requires precision, was used as the average human body model generation method. Products that have a size system such as clothing, shoes, gloves, and hats have a relatively low body fit sensitivity compared to wearable robots, and are manufactured using a mass production method. In the existing mass production method, the approach of developing all the size sections subdivided into 10 or more and the average human model for each section and applying them to the product is not suitable because production efficiency and economy are low. For this reason, in the case of applying the size system of a product line that requires conformity to the shape and dimensions of a human body, most of the approaches are to build a size system based on simple dimensions such as circumference, length, and width using a two-dimensional body size database. In most cases, only one to four limited average human models representing 25 th-75 th % are created and used as a supplement to product development. However, since the wearable robot for the disabled with leg paralysis needs to be customized for pHRI so that an integrated connection between the human body and the robot can be made, a simple dimension-based size system applied to existing products and a wide range of median values are not suitable. In addition, 3 DP-pHRI based on a size system using a limited number of average human body models cannot implement an appropriate body shape fit. Therefore, the size system of 3 DP-pHRI should be subdivided into more detailed size sections and an average human model representing each subdivided section should be created and developed by referring to the shape of the human body surface of each created model. In this study, we developed 3 DP-pHRI based on the size system that is subdivided into 18 size sections and libraryized by applying the most effective method among the methods used in the development of the existing size system. The value and importance of this study in that 3 DP-pHRI based on a size system that can be mass customized with relatively little effort compared to the existing body shape customization of the wearable robot, which required significant effort, was developed and presented as a new alternative. In this study, the pHRI of a wearable robot for rehabilitation training for people with paraplegia was studied. Patients with paraplegia due to SCI are divided into subacute and chronic phases based on 6 months after the onset of SCI. The subacute period is a period of intensive rehabilitation training. The subacute leg paralysis disorder has relatively less muscle contraction compared to the chronic leg paralysis disorder, and the muscle contraction is minimized depending on how actively rehabilitation training is performed during the subacute period. The wearable robot selected as the study target is the primary treatment target for subacute lower limb paralysis disorders, and the secondary treatment target for partial paralysis disorders such as subacute stroke and hemiplegia. To develop the size system of the wearable robot's 3 DP-pHRI targeting such users, a human body shape database should be used. However, there are various difficulties in securing a database of the human body shape of people with lower limb paralysis disorder.