Digital Triplet Approach for Real-Time Monitoring and Control of an Elevator Security System

Abstract

As Digital Twins gain more traction and their adoption in industry increases, there is a need to integrate such technology with machine learning features to enhance functionality and enable decision making tasks. This has lead to the emergence of a concept known as Digital Triplet; an enhancement of Digital Twin technology through the addition of an ’intelligent activity layer’. This is a relatively new technology in Industrie 4.0 and research efforts are geared towards exploring its applicability, development and testing of means for implementation and quick adoption. This paper presents the design and implementation of a Digital Triplet for a three-floor elevator system. It demonstrates the integration of a machine learning (ML) object detection model and the system Digital Twin. This was done to introduce an additional security feature that enabled the system to make a decision, based on objects detected and take preliminary security measures. The virtual model was designed in Siemens NX and programmed via Total Integrated Automation (TIA) portal software. The corresponding physical model was fabricated and controlled using a Programmable Logic Controller (PLC) S7 1200. A control program was developed to mimic the general operations of a typical elevator system used in a commercial building setting. Communication, between the physical and virtual models, was enabled using the OPC-Unified Architecture (OPC-UA) protocol. Object recognition using “You only look once” (YOLOV3) based machine learning algorithm was incorporated. The Digital Triplet’s functionality was tested, ensuring the virtual system duplicated actual operations of the physical counterpart through the use of sensor data. Performance testing was done to determine the impact of the ML module on the real-time functionality aspect of the system. Experiment results showed the object recognition contributed an average of 1.083 s to an overall signal travel time of 1.338 s.

Digital Twin Driven Requirement Conversion in Smart Customized Design

“…Meanwhile, an elevator, a special industrial product, occurs with the specific building. The environment model, high-fidelity replication of the building environment (e.g., building purposes, passenger flow, weather, and passenger identities), is considered in some DT applications [4], [40], [41]. Although these DTs are mostly applied in the usage stage of the elevator life cycle (e.g., noise control and energy efficiency service), it is worth thinking about integrating environment models in DTRC in the design stage.…”

Digital Twin: Origin to Future

“…IEEE (The Institute of Electrical and Electronics Engineers) believes that in the future, DT will become an indispensable part of machine development as well as of the human-machine symbiotic relationship [82]. Some researchers see 'Digital Triplet' as the next evolution of DT [83][84][85]. In addition to physical and cyber worlds, Digital Triplet also includes the 'intelligent activity world' where humans will solve problems by using DT.…”

Smart Elevator Systems

“…A device that monitors the distance between two elevators prevents them from collisions (Figure 6). A computerized system optimizes travel for both cabins by assigning passengers to cabs most efficiently, reducing wait time and empty journeys, and saving energy [16][17][18] . Simply, the system enables more elevators with fewer shaftsit is estimated to require one-third fewer shafts than conventional elevators, saving core space.…”