Distributed multifunctional gas mass flow controller based on single chip microcomputer
The technical field is as follows:
the invention relates to the technical field of semiconductor manufacturing, in particular to a distributed multifunctional gas mass flow controller based on a single chip microcomputer.
Background art:
flow measurement and control are very important parts of integrated gas delivery systems. Mass flow controllers are common devices in the industry and allow precise control of a gas or liquid. The mass flowmeter adopts the thermal type measurement, the flow is measured by the molecular mass taken away by the split molecules, and the measurement result is not influenced by the change of the gas temperature and the pressure because the thermal type measurement is adopted. The mass flowmeter is a relatively accurate, rapid, reliable, efficient, stable and flexible flow measuring instrument, can be widely applied to the fields of petroleum processing, chemical engineering and the like, and is believed to show great potential in promoting flow measurement.
The mass flow sensor cannot control the flow, and can only detect the mass flow of liquid or gas and output the flow value through analog voltage, current or serial communication. A mass flow controller is a meter that can be detected and controlled simultaneously. The mass flow controller itself is provided with an electromagnetic regulating valve or a piezoelectric valve in addition to the measuring part, so that the mass flow controller itself constitutes a closed loop system for controlling the mass flow of the fluid. The set point for the mass flow controller may be provided by an analog voltage, an analog current, or a computer, PLC.
With the progress of science and technology and the development of society, more and more gases are used as industrial raw materials and energy sources to be applied to industrial production and daily life of people, and certain requirements are required on the proportion and the flow rate of the gases. The traditional gas monitoring mode has large dependence on manpower, complex calculation ratio and communication loss among equipment; meanwhile, the control system of the traditional mass flow sensor is connected with a computer by using a flow display instrument, so that the cost is huge. Therefore, how to improve the mass flow sensor control system and reduce the cost becomes an urgent problem to be solved.
The invention content is as follows:
the invention mainly aims to solve the problem of excessive cost consumption of the traditional digital circuit control, and provides a data uploading cloud to realize real-time monitoring and control.
The technical problem to be solved by the invention is realized by adopting the following technical scheme:
a distributed multifunctional gas mass flow controller based on a single chip microcomputer comprises a gas mass flow sensor, a core controller, an industrial Internet of things and a human-computer interaction system.
The gas mass flow sensor outputs different analog voltage signals to the core controller in different gas environments, and is connected with the core controller through an RS232 bus.
The core controller comprises a main control core processor, an A/D acquisition module, a D/A output module, a power supply module and an RS232 bus, wherein the A/D acquisition module is used for converting analog voltage signals output by the gas mass flow sensor into flow data and displaying the flow data on an interface of a man-machine interaction system, and the D/A output module is used for controlling the flow output by the gas mass flow sensor. The power supply module performs voltage conversion for many times, and the power supply requirements of the modules are met.
The A/D acquisition module is a 12-bit successive approximation type analog-digital converter, supports single and continuous conversion modes, and generates interruption when conversion is finished or an analog watchdog event occurs.
The industrial Internet of things is based on a Lora module and a WiFi module which are connected to a core controller, various real-time data are uploaded, historical data are recorded so as to facilitate monitoring and follow-up analysis, and meanwhile, set data are sent to the core controller to indirectly control a gas mass flow sensor so as to achieve an expected working state.
The Lora module is a long-distance wireless communication module based on LPWAN, supports LORAWAN standard protocol, and is used for serial data transmission bidirectional communication; the WiFi module belongs to an internet of things transmission layer and has the function of converting a serial port or TTL level into a level meeting a Wi-Fi wireless network communication standard.
The core controller, the industrial Internet of things and the man-machine interaction system are integrated on one PC circuit board.
The PC circuit board adopts a scheme of four-layer drawing, reduces the area of the circuit board and is convenient to install in the case.
The man-machine interaction system comprises an LCD display screen and a rotary encoder, wherein the LCD display screen is an LCD liquid crystal of an IIC interface.
The human-computer interaction system is supported by an upper computer, controls and inputs the gas mass flow sensors through the functions of different keys on a main interface of the upper computer, and monitors the working state and historical data of each gas mass flow sensor in real time through a data display interface of the upper computer; on the other hand, depending on the LCD display screen, the control object is selected through the rotary encoder, the object is selected by utilizing the longitudinal key freedom degree of the rotary encoder, and the selected adjustment object can be corrected and typed through the rotary encoder. The human-computer interaction system accurately displays the working state of the gas mass flow sensor in real time.
The upper computer is a PC or a computer.
The invention has the beneficial effects that: the gas mass flow controller comprises a plurality of functional modules for collecting data, uploading data, setting parameters and the like, and a control system is realized in a case in a centralized manner, so that the cost of the traditional digital circuit structure control is greatly reduced, the human resources of the traditional monitoring system are liberated, and a data network of a mass flow sensor is innovatively established, so that the control of a factory is more centralized, accurate and convenient.
Description of the drawings:
FIG. 1 is a schematic view of the overall structure of the present invention;
FIG. 2 is a diagram of the hardware design of the present invention.
In the figure: 1. a host; 2. a slave; 3. a gas mass flow sensor; 4. a gas delivery pipeline; 5. a PC circuit board; 6. a Lora module; 7. a WIFI module; 8. an LCD display screen; 9. the system comprises a rotary encoder, 10 and a master control core controller; 11. an A/D acquisition module; 12. a D/A output module; 13. an RS232 bus; 14. and a power supply module.
The specific implementation mode is as follows:
in order to make the technical means, the original characteristics, the achieved purposes and the effects of the invention easy to understand, the invention is further explained by combining the specific embodiments and the drawings.
Example 1
The following describes embodiment 1 of the present invention, that is, a method for accurately indexing the slave 2 and querying data by the master 1 according to the present invention, with reference to fig. 1 and 2.
The core controller, the industrial internet of things and the man-machine interaction system are integrated on a PC circuit board 5. The core controller comprises a main control core processor 10, an A/D acquisition module 11, a D/A output module 12, a power supply module 14 and an RS232 bus 13. The gas mass flow sensor 3 outputs different analog voltage signals to the core controller 10 in different gas environments, and is connected to the core controller 10 through an RS232 bus 13.
The gas flow sensor 3 outputs gas through a gas delivery pipe 4, and is connected to an RS232 bus 13 on the PC board 5. The model of the core controller 11 is STM32, the analog voltage signal output by the gas mass flow sensor is converted into flow data by the a/D acquisition module 11 and displayed on the interface of the man-machine interaction system, and the flow output by the gas mass flow sensor 3 is controlled by the D/a output module 12.
The man-machine interaction part depends on an LCD display screen 8, and a control object is selected through a rotary encoder 9. In specific implementation, the acquired data and the set control parameters can be displayed through the LCD 8. The main interface displays the flow data of the host 1 by default, and the current display equipment can be switched by rotating the rotary encoder 9.
The collected data and the set control parameters can be uploaded to the industrial Internet of things through the WIFI module 7, and the network end can display historical uploaded data, draw curves and the like. The industrial Internet of things terminal can also monitor whether the working state of the industrial Internet of things terminal is within a set threshold range, so that the working safety of the equipment is ensured.
The human-computer interaction system is partially dependent on the upper computer, controls and inputs the gas mass flow sensors through the functions of different keys on a main interface of the upper computer, and monitors the working state and historical data of each gas mass flow sensor in real time through a data display interface of the upper computer.
During specific implementation, the acquired data and the set control parameters can be inquired and detected through an upper computer interface edited by QT. The upper computer interface can select the index number of the equipment to be inquired, and can detect whether the equipment works normally, detect the threshold value of the equipment and compare the actual working condition with the set threshold value condition, so that the working state of each mass flow sensor can be mastered at the PC end.
In conclusion, the invention can complete real-time display, accurate adjustment and control of data on a plurality of platforms in a plurality of ways; data tracing is realized on the platform of the Internet of things, and a perfect flow data network is formed
Example 2
Example 2 of the present invention, an embodiment of the present invention providing a precise gas proportioning, is further described below with reference to fig. 1 and 2.
The human-computer interaction interfaces of the upper computer and the LCD 8 are provided with index numbers of equipment to be inquired, and all parameters such as real-time gas mass flow, set threshold values, alarm threshold values and the like can be obtained by selecting one of the equipment. Through setting a flow threshold and an alarm device, the inflow of the flow is accurately controlled to achieve the purpose, and compared with manpower supervision control, the system is more convenient, the cost is reduced, and manpower resources are saved.
The gas mass flow controller can send a control command to the gas mass flow controller or the slave 2 through the industrial internet of things control host 1, change the output voltage of the D/A output module 12 of the corresponding equipment and further control the gas mass flow of the gas mass flow sensor 3.
The gas mass flow controller can be realized by a man-machine interaction system consisting of a rotary encoder 9 and an LCD display screen 8 on the main machine 1. The LCD display screen 8 is used for displaying the flow of the host 1 by default on the main interface, the rotary encoder 9 can be pressed to enter a set interface, a controller can switch parameters to be set by operating the rotary encoder 9, the rotary encoder 9 can be operated after the parameters enter the set interface to select the equipment number to be modified, the numerical value of each parameter in the equipment number is modified, and the equipment number is returned to the main interface again and the data is stored to be modified.
The control function of the gas mass flow controller can be realized through an upper computer control interface, the upper computer interface is provided with task columns for modifying alarm threshold values, flow threshold values, gas flow rates and the like, the index number of the equipment to be modified is selected to modify parameters, and the set parameters can be stored in each slave machine 2.
In the embodiment, the control process of the equipment is visualized, the control system and each working equipment are separated, remote real-time monitoring setting is realized, and unnecessary workload of manual setting and setting errors caused by manual operation are avoided. The control end can also modify the alarm threshold value according to project requirements, so that the monitoring setting of the equipment has universality.
The foregoing shows and describes the general principles and broad features of the present invention and advantages thereof. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.