# Research and Implementation of CPS for Transmission Front Middle Case Assembly Line
## 5 Application Results and Discussions  
### Implementation of the Proposed System  
In this paper, a front and middle case assembly in the transmission assembly workshop of an automobile manufacturing enterprise is considered, and the control system is applied on-site. The management and control terminal of this system is developed by Java and installed on the application server in the form of the Windows platform. The executive terminal of this system is developed by Python and Java and installed on the fixed PAD terminal and mobile phones of workers in the form of an application (APP). Since the transmission is a mass-production product on the assembly line, experiments were performed over a six-month period. Real-time control of the assembly process in the engineering instance was realized through the following operations. 1. Data integrated management  
In the engineering instance, work-order information was generated by systems applications and products in data processing (SAP) system and sent to the workshop and the assembly. The corresponding assembly tasks were planned by the workshop group leader and sent to the corresponding workers. Tools, materials, and other resource information were provided by a manufacturing execution system (MES), and information on automation equipment was obtained from the programmable logic controller (PLC). Interfaces between the constructed system in this paper and these systems were developed, and all of the data from these systems were unified, defined, and managed under the support of the data model in the proposed system. 2. Monitor of assembly worker  
According to the radio frequency identification (RFID) data acquisition scheme of assembly workers, both the workers involved in the assembly tasks and their working time can be obtained from this system. When the assembly workers are within the RFID sensing range, the corresponding workers' information can be queried through the RFID signal. If a task is in process, the working time of the participating workers is increased correspondingly. When the assembly task is completed, the total working time of the participating workers can be obtained. Figure 7: A basic interface of the management and control terminal. Monitor of logistics  
Logistics distribution of assembly resources (tools, parts, and materials) is accompanied by the work order. The large assembly resources are placed in trays with RFID tags and distributed by automated guided vehicles (AGVs). Each of them is labeled by a two-dimensional code. The workers receive them through scanning, and the corresponding received information (receiver, receiving time, receiving station, etc.) is recorded in the system. Administrators and workers can access relevant information at any time. The small assembly resources are distributed directly to the line inventory before production. Monitor of assembly progress  
The assembly progress, i.e., the execution state of the process, is fed back by workers in the fixed terminal or the mobile terminal. It usually contains five state points: start, suspension, continuation, completion, and end. As shown in Figure 8, by comparing the recorded start and end times and the initial planned ones, we can determine whether the assembly progress lags behind. And the abnormal assembly quality can also be detected timely according to the quality inspection results before the end of the assembly. The worker should report the abnormality, and the abnormality handle module will be triggered when the assembly schedule lags behind, or the quality is abnormal. Figure 8: Assembly progress monitoring. Through the application of the proposed system in a Chinese automobile manufacturing enterprise for a period of time, conclusions can be drawn that all of the above operations are conducive to the timely discovery and handle abnormalities of the worker shortage, untimely resource distribution, and abnormal quality, as well as the adjustment and optimization of assembly schedule in case of progress deviation.