# Digital Twin-Based Vibration Monitoring of Plant Factory Transplanting Machine
## 4 Conclusions  
This paper proposes a physical entity vibration monitoring method for the DT plant factory transplanting system. Firstly, a demand analysis for the physical entities of the DT plant factory transplanting system is conducted, focusing on practical applications. Then, an optimal deployment plan is designed based on the AD theory. The feasibility and effectiveness of the proposed method are validated using the digitalized system robotic arm that is tailored for vibration analysis requirements. The customized deployment plan takes into consideration the industry's profitability, the technical feasibility of the application, the worker safety at the field site, and the reliability of plan implementation.  
Next, a comparative analysis based on data was conducted to evaluate the conditions of the equipment used for transplanting plants. The \(Z\)-axis exhibited the highest magnitude, measuring 2.1 m/s\({}^{2}\). When comparing the clouds, it is evident that the \(Z\)-axis and \(X\)-axis exhibit a more noticeable trend of vibration above the transplanting robot compared to the \(Y\)-axis. In conclusion, when comparing the modal vibration power spectral densities of the transplanting machinery in various operational situations, it is evident that the amplitude in the \(Z\)-axis direction experiences a notable rise specifically during the medium-speed transplanting of 3000 plants per hour in working condition three. The amplitude in the \(X\)-axis direction is higher than the other two directions within the 0-80 Hz low-frequency range. In such circumstances, the transplant efficiency can be upheld at a high degree while ensuring that the vibration signal in the \(XYZ\)-axis above the transplant robot remains mild and appropriate for the transplantation process.  
There are certain limitations to the application of this method in agricultural production. Firstly, it is suitable for controlled agricultural production environments to ensure the stability of sensor data collection and transmission. Secondly, it is applicable to highly automated agricultural production equipment to ensure consistency between virtual entities and physical entities. Thirdly, there is a need for an adequate number of sensor nodes or the integration of image recognition algorithms to establish a virtual mapping with sufficient accuracy. At the same time, it is undeniable that this technology holds potential for promotion and application in various industrial sectors. For instance, it can find practical applications in areas such as 3D logistics management, vehicles, power plants,aircraft, complex electromechanical equipment, 3D warehouses, healthcare, manufacturing workshops, and smart cities, where there is a demand for its implementation. The application ideas and strategies proposed in this research can also serve as a reference for the implementation of digital twin concepts and technologies in related fields.  
Conceptualization, K.C.; data curation, L.Z.; formal analysis, K.C. and Y.Y.; funding acquisition, Y.Z. ([PERSON]); investigation, Y.Y. and B.Z.; methodology, K.C., K.N. and X.J.; project administration, L.Z.; resources, K.C., Y.Z. ([PERSON]) and B.X.; software, K.C.; validation, K.C., B.Z., X.J. and Y.Z. ([PERSON]); visualization, B.X.; writing--original draft, K.C.; writing--review and editing, Y.Z. ([PERSON]). All authors have read and agreed to the published version of the manuscript.  
The National Key Research and Development Program of China Sub-project grant number 2021 YFD2000705.  
Not applicable.  
Data availability Statement: Data are contained within the article.  
The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.