“Digital Twins” means that copy a real block making production line in a digital method, which simulates the actions and movements of the production line in the real world. It is the virtual reality of design, crafts, manufacture, and the whole block production line so as to realize the effect of a “dark factory” which can boost R&D and manufacture efficiency, forecast malfunction, reduce production costs, and save the loss, etc.
The digital twins of QGM block production line: Firstly, equipment synchronization. Smart equipment and sensors are introduced in this process based on the actual block production line. Secondly, put up a virtual production line that is prototyped on the real one. (1) build a 3D model of each part of the actual block production line, (2) place the finished 3D model in the virtual equipment, (3) input the real data. With all the steps done, the correspondence between the real production line and the virtual one is realized.
Case 1: Virtual Cuber Commissioning
The real-time data exchange is conducted through SIEMENS PLC and a 3D digital virtual model. The virtual lengthways latch conveyor delivers the after-curing blocks to the cubing area. Then the operator taps the HMI page in the Siemens control system to select the auto-running mode. When blocks are detected in position, the cuber in the model goes down automatically; the clamps collect blocks; the cuber then goes up, moves to heavy-chain position and goes down to stack the blocks. So the automatic running track of cuber system can thus be traced. This can avoid damage to products due to the commissioning process of the line and can train operators at a low cost.
Case 2: Virtual Mold Change
Similarly, exchange the real-time data through SIEMENS PLC and 3D digital virtual model, operate mobile panel, switch to commissioning mode, and make the following steps: (1)unlock the facemix feeding car; facemix feeding car goes backward; mold frame and tamper head go up in position in order to avoid mechanical intervening mold-change system; mold-change system kicks in; low down the mold frame and tamper head in position and then unload; mold-change system moves the mold (the one needs to be changed) to hoist position. All these steps are directly displayed in the 3D digital model, which helps commissioning, mold-change practice, etc.
With this program, the production line is monitored at any time. The real production status and datum are sent to the displayer with several clicks. In daily operation maintenance, the data are exchanged and accumulated. The smart analyzing method of big data provides data support to production line R&D, production, and operation maintenance so that the R&D technology and production efficiency are increased.