## 4 Application of the Concepts: Design of an In-Line Measuring Machine
### Implementation of Connectivity  
In general, a control system for a measurement machine has four main components that work together to generate, condition, and analyze data: Sensors, edge devices, fog devices, and the Cloud. The implementation of Connectivity starts with the definition of the signals that need to be transported for analysis, as well as the place where processing will occur. Figure 10, which was derived from the frame introduced in Figure 1, maps the sources of data to the hardware and the level at which processing is performed for the in-line measuring machine. As seen in Figure 10, the lowest level is where the basic signals are collected, and where actuators respond to impulses sent by the control of the machine. Generally, typical response time at this level is between 1 and 100 milliseconds and data capability manage  
Figure 10: Control architecture of In-line Measurement machine. Connectivity, data flow and distribution of analysis, and support for decision making. ment reaches from bits to megabytes. In this particular case, the devices at the lower level have the following characteristics:  
* Laser displacement sensor (LDS): This instrument performs the essential basic function of the machine. It measures the height at specific locations of the workpiece. In this case, the laser is calibrated to perform 30 measurements at each location in about 0.080 s
* Positioning system. This system transports the laser sensor to the location where measurements are made. It is actuated by linear motors, and has a travel space of 600 by 600 mm. The gantry system can reach speeds of 6 m/s, with a resolution of 0.001 mm. Linear encoders report the position of the laser head to the GC at any given instant. * Button box: The operator interacts with the control and paces the measurement process through the control buttons. After placing the part in the pallet, the operator can start the measuring process by pushing a button. The operator can also release the part, after the process, or can stop the process in an emergency situation. The time at which the start button is pushed is recorded and sent to the Cloud. * Pneumatic actuator: The actuator is responsible for transporting the part in and out of the measuring volume. Sensors are triggered when it reaches its limit positions. * 3-axis accelerometer (MMA7361): This sensor records the accelerations in different directions as the gantry goes through the measuring cycle. These data are intended to provide information about the health of the operation. The GC takes data from these accelerometers at a rate of 400 Hz approximately. Edge computing takes place at the second level, where the processing devices, i.e., the GC and the LDS drive, receive data from the sensors, which is then filtered, classified, and formatted. The response time of those elements depends on the specific function they were programmed to perform. Specifically:  
* LDS Controller received data from the laser sensor. Processing at this stage consists of scaling, filtering, and mathematical operations. This control was programmed to obtain the average of 30 measurements, and then deliver these data to the GC. LDS driver sends its data via ethernet communication using UART protocol over RS-232C interface or by using analog signals from 0 to 10 Vdc. * Galil controller (GC) is responsible for coordinating and ordering the motion of the gantry, with the measurements taken by the laser. The controller synchronizes the data from both laser and encoders to form a coherent stream of data. In addition, data from the 3-axis accelerometer are also synchronized with the other signals. The control performs these operations in about 200 millisecond. For this purpose, it uses about 4 KB of its 32 KB capacity. * XDK BOSCH (XDK) is a platform of environmental sensors that monitor pressure, temperature, vibration, and humidity. XDK process capabilities allow edge computing to transform data in valuable information of the machine surroundings and give an intelligence level to the machine.