Hardware and software system for monitoring the modes of the finishing operation on automatic machine

. The prerequisites of the market and competition requires the efficiency of production of industrial enterprises. This requirement can be met by the tools of Industry 4.0. But many enterprises have unique technological equipment without the ability to connect digital solutions such as IIoT and Supervisory Control and Data Acquisition (SCADA). IIoT and SCADA enables monitoring of the equipment condition, which makes it possible to monitor technological process compliance with required modes, as well as the technical state of the equipment. The paper presents the development of software and hardware systems to eliminate this gap. The paper presents the scheme of the hardware and software system for monitoring the finishing machine, which contains sensors for monitoring the technical and technological characteristics of the machine and recording, analysing and visualizing data using the Winnum Platform. The double-acting finishing machine is a special class of equipment that allows to obtain a surface with precision quality. The presented hardware and software system can be used for other finishing machines with a similar design.


Introduction
Many industrial enterprises have both modern and outdated but unique equipment. The work of the enterprise in a market economy and competition dictates the conditions for improving product quality, reducing production costs and increasing productivity. In addition to standard methods and techniques that meet these requirements, there are specialized digital solutions, the popularity and effectiveness of which is growing with each year.
The research topic relates to the field of instrumentation and concerns the development of a hardware and software system for monitoring the modes of the technological process of fine-tuning high-precision flat surfaces of parts for precision mechanics, instrumentation and aviation technology. This study considers the finishing operation of the details of a piezoelectric vibration sensor.
The lack of traceability of the finishing process, and as a result, the irrational choice of technological modes, sudden breakdowns and wear and tear of equipment, entails a deterioration in the quality and an increase in the cost of products. The use of industrial Internet of things (IIoT) allows to combine the equipment, cloud computing and analytics. As a result, it promotes the efficiency of manufacturing processes. The increase of the traceability of the finishing operation increases the productivity of the operation, as well as ensures a rational relationship between quality, labor intensity and price [1][2].
Modern solutions in the field of IIoT provide a wide range of tools and techniques for monitoring. Supervisory Control and Data Acquisition (SCADA) systems are used to collect information from industrial equipment that is part of the IIoT environment. IIoT and SCADA systems together make it possible to register signals from sensors and monitor the state of equipment [3][4][5].
For example, in the study [6] the authors aimed to solve the problem of monitoring wear and breakage of a carbide tool during high-speed machining of titanium plates. The research [7] shows the possibility of implementing remote monitoring of manufacturing processes, but they also identified the problem of developing the infrastructure of the IIoT. The study [8] proposes a methodology for developing three-dimensional scenes of industrial sites and equipment, as well as the architecture of a system for collecting data from industrial equipment.
It should also be noted that various connection options are possible. Authors of the study [9] implemented the registration of a temperature signal, as well as an alarm about emergency situations, with the use of a PLC controller. Article [10] shows that instead of a PLC/PAC controller, an edge controller can be used as a more reliable and secure option for connecting equipment to the IIoT.
Monitoring of manufacturing processes and the state of equipment is an important parameter to ensure the desired quality of products. At the same time, connecting nonstandard equipment, which is a double-acting flat-finishing machine, is a separate task, since it is necessary to register information from different machine nodes using various inconsistent sensors. At the same time, the manufacturer of the equipment did not provide standard methods for connecting to monitoring systems, so the development of a hardware and software system for monitoring the finishing operation is a relevant task.

The equipment in question
The finishing operation was performed on a double-acting flat-finishing machine (Fig.  1). The machine has a control system for the rotation speed of the finishing circles, pressure between them, and operating time. The finishing process assumes the presence of a lubricantcoolant. The control system does not receive this information. Although the presence of a lubricant-coolant is necessary to cool parts during processing and remove metal sand from the processing zone. The rotation of the finishing circles is carried out separately from each other by two electric motors. The lower circle control motor transmits rotation through the gearbox, as it is required to rotate the separators. Separators are rotated by gearing and designed to separate workpieces from each other and to move them. Finishing is performed by applying pressure between the finishing circle and the workpiece. Therefore, it can be concluded that monitoring of the rotation speed of the finishing circles, the pressure between them, the processing time and the presence of lubricant-coolant is a necessary feature. The control of these parameters will ensure the required quality of products and prevent the occurrence of defects.
In addition to monitoring the parameters that are responsible for the quality of surface treatment, it is proposed to control the temperature and vibration of the upper and lower motors. Control of these parameters would enable monitoring of the equipment condition and provide timely maintenance in order to prevent equipment breakdowns. The first vibration and temperature values should be used as nominal values. Further deviations from the nominal temperature and vibrations during engine operation should be considered as a violation and maintenance should be carried out.

The development algorithm of a hardware and software system
In order to develop a hardware and software system, it is proposed to use the algorithm shown in Fig.2. The algorithm consists of such key steps as determining technological and technical parameters, choosing a platform for deploying a monitoring system, choosing a controller to connecting sensors, selecting sensors with appropriate protocols, building a circuit and subsequent analysis of the circuit in order to verify the presence of sensors for monitoring of all required equipment parameters.

Architecture of the IIoT platform
In this research it is proposed to use the Winnum Platform as a platform for the IIoT and a SCADA system. It is a modern software for monitoring the state of equipment and manufacturing processes. The Winnum Platform was chosen because of the Winnum Connector module and the Winnum Hardware OE Rev. 3 Lite (Fig.3) controller adapted for it. It allows to combine all sensors into a single system for recording and transmitting information about the state of the equipment and the technological processing modes. This controller is a way to connect any type of industrial equipment sensors to the Winnum platform.   Wire protocol, located inside the communication module. It allows to evaluate up to six discrete states.
The architecture of the IIoT is shown in Fig.4. Using the Winnum Platform web interface, the parameters and state of equipment can be remotely monitored from any connected workstation. The main software application is the Winnum Platform, which is hosted on the enterprise server. Winnum Platform is designed to manage and visualize production processes, it also generates a data model and interacts with users and the database. The same server hosts the Winnum Cloud application, which enables the management of data and is based on the Cassandra DBMS, which in turn ensures the collection and storage of information obtained during the manufacturing process and is intended for storing the received data. As mentioned earlier, Winnum Connector is a system for converting signals from equipment and transmitting data to the data base.

The development of hardware and software system
In this research the proposed algorithm is used to develop a hardware and software system for monitoring the parameters of the finishing machine. Table 1 presents the parameters that need to be monitored and the types of sensors required. All the machine parameters are conditionally divided into technical and technological ones. Technical parameters are responsible for performance. Technological parameters are responsible for ensuring the specified quality of the treated surface. Consider the characteristics of the selected sensors. Strain gauge Tedea 1022 C3 for pressure control, which allows to measure the load in the range from 3 to 200 kg. For the speed of the finishing wheels monitoring, an NPN 8-24 V tachometer is used, which reads the rotation speed in rpm and has a measurement range from 10 to 9999 rpm. For the speed of the motors monitoring and the possibility of sending a control signal, it is proposed to use an encoder H-ZSP2504EC-24-C-500 with 500 PPR. The measurement of the operating time is executed with a strain gauge sensor that measures the pressure, but the signal is interpreted as time under load. The coolant supply is controlled by the SBY333 liquid flow sensor, which controls the flow rate from 1 to 25 l/min, the operating temperature is from -15˚C to + 60˚C. The lubricant-coolant level is controlled by the capacitive level sensor CSN I06P5-31N-10-LZ with discrete measurement and hysteresis from 3 to 15%. Engine vibrations are monitored using a BALTECH VP-3470-Ex vibrometer, which allows to control vibration accelerations from 0.5 to 300 m/s2, while the operating frequency range for measuring vibration acceleration is from 2 to 10'000 Hz. Vibrometers are installed on all shafts of the machine. Temperature control is an important parameter, so it helps to avoid overheating of the engine during its operation. The temperature is determined using a K-type ThermoSensor Touch Laserliner 082.035.4 temperature sensor, the measurement range of which is from -50˚C to + 400˚C.

Results
The resulting scheme of the hardware and software system for monitoring technological modes and equipment state is shown in Fig.5. Winnum Hardware OE Rev. 3 Lite is used as the data bus in the diagram, which is connected to a sensor for receiving signals about the state of technological modes of finishing process and the state of the equipment. Ethernet is used as the communication protocol. Further, the data received from the sensors is transferred through the Hardware OE Rev. 3 Lite to the Winnum Server, where the registration and processing of this data is performed. In order to manage and execute Winnum Server workstations, one workplace is allocated for platform administration. Users who have access to data on the finishing process connect to the Winnum Platform from their workplace using the web interface. From each remote workstation connected to Winnum Server, it is possible to remotely monitor the processing process and equipment indicators, which promotes quick decision making on organizational and technical levels. For example, by tracking the operating time of the machine, both the technological mode of finishing operation and the loading of equipment during the work shift can be assessed. The proposed scheme of the hardware and software system, consisting of a set of sensors that enables registration of the technological and technical parameters of the finishing machine, the microcontroller Winnum Hardware OE Rev. 3 Lite and platforms of the IIoT and SCADA Winnum Platform allows to monitor the finishing process for any class of equipment with a similar purpose and kinematic scheme. It is also possible to install additional sensors and expand the application of the proposed scheme to control additional parameters, such as lubricant-coolant quality, heating temperature in the processing zone, etc.
Built-in algorithms detect deviations in both equipment and processing programs, providing a complete understanding of the most critical manufacturing areas and technologies that need to be addressed. The identified deviations make it possible to determine the available reserves and temporary losses that affect the economic efficiency of the use of equipment. Thereby, controlling the operating time of the finishing machine enables Winnum to calculate the deviations from the planned time caused by the change in technological modes and to provide information about the state of each finishing circle.

Conclusions
The obtained data on technological modes, the state of the equipment, the operating time during the work shift, as well as the information received on changes in the control program in the process of performing the operation on the finishing machine, make it possible to speed up the production of products and increase the efficiency of controlling the finishing process.
The use of the IIoT platform and the monitoring hardware and software system allows to optimize production processes, speed up the production cycle and improve product quality, as well as reduce production costs while reducing waste, reduce equipment downtime and increase the efficiency of the production resources usage.
The developed hardware and software system allows monitoring the finishing process, optimizing the equipment load and allows to monitor the operation of the equipment in real time, which makes it possible to quickly respond to equipment malfunctions and prevent them by warning about the need for maintenance.
Further work will be devoted to setting up the Winnum Platform for the finishing department of an instrument-making enterprise and collecting data on the state of the equipment in order to optimize production processes and improve the quality of manufactured piezoelectric vibration sensors.