# A Method for Building a Mixed-Reality Digital Twin of a Roadheader Monitoring System
###### Abstract
Through virtual modeling of physical objects in the real world to obtain the corresponding digital model, and with the aid of data processing technology and digital simulation technology to fulfill the monitoring, control, diagnosis, prediction, and other functions of the physical entity, the physical entity and the digital model are connected at an appropriate synchronization rate via digital communication technology to realize the two-way mapping between the physical entity and the digital model [13]. Thus, it becomes possible to comprehensively and stereoscopically present the excavation information to the driver at the visualization terminal, enhancing the driver's visual perception and situational awareness. This allows for greater transparency and efficiency in the excavation process while minimizing the interference of the complex roadway environment on the driver. Digital twin technology has long had application precedents in intelligent coal mining and is becoming increasingly widespread. [PERSON] et al. introduced 5G communication technology, IoT technology, and bionic intelligence technology into the traditional fully mechanized mining face and proposed the concept of a digital twin intelligent mining face [14]. [PERSON] et al. verified the feasibility of the digital twin-driven intelligent control system of the cantilever roadheader by deeply integrating the physical entity of the tunneling face with the digital virtual model of tunneling information and making this interaction bidirectional [15; 16; 17]. [PERSON] et al. conducted in-depth research on the driving and bolting integration machine through the physical simulation and real-time driving technology of historical data and carried out the kinematic fast simulation analysis of the driving and bolting integration machine [18]. Traditional visualization terminals are often based on VR technology or AR technology. VR technology utilizes computer equipment to render a three-dimensional digital virtual space, and its hardware limits the user's field of vision, thereby weakening the user's perception ability of the real environment [19]. AR technology can use a computer to superimpose virtual information and render it into a video stream, then overlay the video stream onto the physical environment, and interact with the user through program control, but the mutual influence between the virtual and the real is very limited [20]. MR, as an imaging technology between VR and AR, possesses both the human-computer interaction characteristics of VR technology and the reality fusion characteristics of AR technology, and has the unique advantage of strong virtual-real interaction, that is, it can achieve \"coexistence and interaction of the virtual and the real\" [21]. This paper takes the EBZ roadheader as the research object. Aiming at solving the problems of the complex tunneling roadway environment, serious interference, large blind area for the driver's field of vision, difficult precise operation, and low transparency of cutting information, a construction method of an MR digital twin monitoring system of the EBZ roadheader is proposed, combined with digital twin technology and mixed-reality technology. It will lay the foundation for realizing intelligent remote monitoring of the roadheader, improving the efficiency of the roadheader, and achieving intrinsically safe tunneling. Beyond mining, this methodology can be extended to the monitoring and control of other mining equipment, predictive maintenance in manufacturing, and infrastructure management in smart cities.