Research On Architecture Design And Application Of Digital Twin System For Parallel Mechanism

Parallel mechanism has been widely used in many fields such as bridge construction,medical assistance,aircraft maintenance and intelligent manufacturing because of its strong reconfiguration,large working space,fast moving speed and high precision.However,due to its precise and complex structure,long operation cycle,harsh working environment or broad working area,how to automatic the mangement effectively and control of parallel mechanism to achieve real-time operation and interactive operation becomes a difficult problem.As a disruptive technology,Digital Twin(DT)realizes real-time visual supervision of the life cycle of physical entities by mapping physical and virtual entities effectively.and it provides an idea for the management and maintenance of parallel mechanisms.To realize the supervision for the full life cycle of the parallel mechanism and provide a case for the inplementation of the digital twin technology.This paper applies digital twin technology to the parallel mechanism,proposes a theoretical model of digital twin,establishes an operation mechanism of the theoretical model,and develops a digital twin system of the parallel mechanism.The main research work and innovations of this paper are as follows:(1)The digital twin technology was introduced into the parallel mechanism,and the theoretical model of digital twin which is based on perceptual control was proposed creatively,which provided a theoretical basis for the application of digital twin technology.The theoretical model was divided into six dimensions : physical entity,virtual entity,perceptual control,twin data,connection and service.A sound operating mechanism was established,which provides a standardized model for the development of digital twin systems.(2)Taking data acquisition and industrial internet data transmission as the underlying processing unit,the digital twin system for parallel mechanism was designed and developed,which realizes the supervision of the full life cycle of parallel mechanism,and improves the level of automatic supervision and visualization for parallel mechanism.To enable the digital twin system has the ability of state perception,a data acquisition system was built by using Arduino and sensors;To realize the connection between equipment and application,OPC UA(OLE for Process Control Unified Architecture)industrial internet protocol was applied to the system;To ensure the stability of the experimental platform structure,the mechanical simulation was carried out on the of the 3D model of the parallel mechanism.(3)The multi-motor cooperative control algorithm was designed and developed to realize the automation of motion control for parallel mechanism.The method of fault monitoring for parallel mechanism components such as stepper motor based on vibration signal was proposed,and the fault monitoring software of parallel mechanism was developed,which provides a train of thought for fault monitoring of parallel mechanism.Finally,the digital twin system was tested on the experimental platform of flexible traction parallel mechanism.The experimental results indicate that the theoretical model and the system are effective and feasible.