Researches On The RFID-based Workflow Activity Recognition

Ubiquitous computing is a human-centric computing paradigm that integrates the human and the surrounding physical environment in order to provide people with the computing resources and information service they need proactively through intelligent human-computer interaction.People can work and live better in the ubiquitous computing environment.As the core technology in the field of ubiquitous computing,activity recognition technology aims to first observe and obtain the data of a series of human actions and environmental conditions through modern information technologies(such as video surveillance,sensors and wearable devices),then based on the observations to infer information on human activity,vital signs and environmental conditions,and further provide accurate and reliable personalized service in a human-centric computing environment.Since 1980,activity recognition researches have provided personalized support for a wide variety of applications and have played an important role in many other industries.However,in recent years,with the increasing intelligence of information services and the expanding of the scope of activity recognition application,the tasks of activity recognition present the trend of elaboration and complication.Among them,workflow activity recognition has become the focus of activity recognition.The workflow activity is generally defined as a temporally ordered group of procedural activities for accomplishing a task.The workflow activity is a higher level of abstraction based on activity recognition and it is also more practical and closer to the user.The recognition of workflow activities can better help people to complete a specific task.For example,workflow activity recognition can assess the skill proficiency and accuracy of a workflow executor in a skill assessment application,and can automatically analyze the degree of completion by automatically recording the duration of each step performed by the executor in the workflow.In addition,workflow activity recognition can be used in the learning assistant applications,to remind beginners what is the next step,and whether there are any missing steps.In this paper,aiming at the problems existing in the current research in workflow activity recognition,an RFID-based workflow activity recognition method is proposed.The following aspects of research work:(1)In the aspect of workflow activity perception,this paper proposes for the first time the use of RFID phase signal as a perception tool of workflow activity.Through the RFID phase signal,the movement state information of the associated objects in the workflow activity scene can be captured accurately and sensitively,thus providing a reliable data source for the establishment of the activity recognition model.Besides,the sensing scheme based on RFID phase signal also has the advantages of device-free,battery-free and privacypreserving.(2)In the aspect of workflow activity modeling,this paper introduce the VQ-HMM model which is widely used in speech recognition to establish the model of workflow recognition,and a series of data processing techniques have been integrated to complete the method design in order to adapt to the recognition task of workflow activity.The phase information collection technology,feature extraction,vector quantization,hidden Markov model and sequence analysis technology are studied in this paper.And the RFID-based workflow activity recognition method is designed and implemented in this paper.(3)For the RFID-based workflow activity recognition method proposed in this paper,we conducted experimental verification and result analysis.We established the experimental environment and proposed the evaluation index,then compared the method of this paper with the accelerometer-based workflow activity recognition method.The experimental results show that the proposed method has higher accuracy,precision,recall and F1-score.This paper first introduces the background and significance of workflow activity recognition research,analyzes the current situation and existing problems of workflow activity recognition research,and puts forward the technical route of this research.Then,the workflow recognition method proposed in this paper is studied and designed in detail.The method is verified and analyzed experimentally.Finally,a workflow activity recognition system is designed and implemented,and the performance of the system is evaluated in practical application scenarios.