Mathematical Expression And Visual Assessment Of User Cognition In Natural Interaction Of Virtual Reality Environment

The ultimate goal of product or human-machine system design is to help users achieve their goals and have a good interaction experience.Therefore,acquiring the user data about cognition,behavior,and intent is crucial to the design of products and human-machine systems.Because of its intense immersive characteristics,Naturally Interacting Virtual Reality System(NIVRS)enables to obtain users' natural and real cognitive and behavioral data through the natural interaction between user and the virtual products.These incomparable advantages to other technologies become a research hotspot in current and future human-computer interaction technology.At this point of view,this paper constructs the Cognition-Behavior-Environmental theoretical framework,in which the virtual natural interaction environment,user perception and user behavior including the internal and in-depth logical relationship between each other was researched.A visual cognitive assessment model based on cognitive tasks is proposed and used for testing and evaluation of new products to reduce new product development costs and shorten development cycles.The premise of natural interaction is mutual understanding,and the key to understanding lies in whether the object itself can be correctly expressed.This article focuses on how the system understands user cognition,that is,the expression of user cognition.A solution include conceptual extension expression and fuzzy mathematics was applied to express user cognition which convert the research of complex subject into the research on behalf of its factor set.As a complex and subjective object,user cognition is now expressed as the mathematical form of system understanding,which lays a theoretical foundation for the establishment of natural human-computer interaction.After that,use the internet text mining technology to obtain the user's cognitive factors,which achieve the mathematical solving of user cognition.User cognition is hidden knowledge,difficult to snoop,but user behavior is visualized and can be assigned value with computer language,so user cognition can be identified by capturing user behavior if the accurate mapping relationship between user cognition and user behavior was established.The interaction between human and system is different from the human-human interaction.The interaction between human and human is ambiguous,however,humans' operation on system must be precise.Therefore,the construction of accurate mapping relationships between user cognition and user behavior is required which is necessary prerequisite for forming natural interactions.This paper uses the following methods to establish a precise mapping relationship between user cognition and user behavior:(1)Taking the factors of user cognition as the image of the gesture semantic design.Since the factor set has been solved,the corresponding gesture set is also determined.(2)Mathematical value assignment of user gestures in terms of eigenvalues,determining the mathematical conversion relationship between user cognition and user behavior,realizing the visual expression of user cognition.(3)training gestures based on eigenvalue expressions and storing them in knowledge base to improve gesture recognition probability and assist system decision-making.In the human-computer interaction system,the goal of the user is to complete cognitive tasks through behavioral operations.The cognitive task consists of a sequence of behavioral operations that express the user's final intentions.The natural gesture operation is one of the most straightforward methods to express user intent,the system senses the user cognition and makes decisions by detecting user's natural gestures and understanding their behavior.Therefore,a key content of this topic is to establish a natural gesture interaction system based on cognitive tasks,cognitive task-based system makes it possible for machines to detect user behaviors to understand user cognition and make effective decisions.As technical support,the design of NIVRS solves the problems of virtual reality which is mainly reflected in the following three aspects:(1)Natural interaction technology.The natural interaction and data communication between user's posture information,position information,interaction information with virtual depth-space environment.(2)Interaction constraint technology.It solves the interaction binding constraints between body mapping poses and virtual rotating bodies in the virtual reality scene and other several interaction constraints in the virtual environment.(3)Entropy-based Multi-criteria System Decision-making Method(EMSDM)in the framework of cognitive tasks was proposed to improve gesture recognition rate and accuracy.At the end,NIVRS was built as an experimental environment in which a user scenario about virtual home is built,Attia Pot and Smart Fridge,these two products that at the design stage in the virtual home were used as evaluation cases,that is,users were asked to performs the cognitive tasks of the two products,during which the system recognizes user behavior and understand user cognition,accordingly complete the user cognition and interaction assessment about product design issues of the two products.The experiment successfully demonstrated the mathematical expression method of user cognition proposed in this paper and the visual assessment of user cognition.