Computer Process Control – Functions, Diagram, types and advantages

Computer Process Control

Computer process control can be defined as the use of a digital computer to manage a manufacturing process. It specifically relates to processes that are continuous or semi-continuous. It would gauge process parameters like pressure, flow rate, and temperature. The last control element in a process, such as valves, switches, and furnaces, would be activated as well as some strategy optimization. We may assess the condition of the machinery, the effectiveness of the manufacturing process, and the product quality with the use of a computer process control.

Diagram of computer process control

• It would do the measurements and data acquisition
• Data conversion would be done with scaling and checking
• It would display the process details
• Controlling and transferring data
• Process output will be compared with the required output
• It would monitor and record the events and sequence
• Data logging and computations
• Control actions

1. Computer process monitoring

• In this case, the computer will keep an eye on both the machinery and the process to gather and record data about it. The process won’t be directly managed by the computer.
• Process data, equipment data, and product data are the three sorts of data that the computer would gather while the process was being monitored.

a. Process data: This is the measured value of the process performance representing input parameters and output variables.

b. Equipment data: This information demonstrates the equipment’s status while it is doing the procedure and how it does so.

c. Product data: This will be the production data of a manufacturing plant

2. Direct digital control :

• There are some conventional components in this system, and a digital controller has been installed in their place.
• The digital computer can perform comparator and controller tasks as well as some safeguarding procedures.
• The DDC control can manage multivariable processes, and they can do this by interacting with various elements.
• Computer control software would specify each control function, the setpoint, and the deviation from the nominal Because only one processor is used for the entire process, a single error could disrupt a huge number of controlled variables and cause the process to stop. This is the main disadvantage of direct digital control.

3. Distributed control system :

• The overall task will be split among all the computers in a distributed control system, which has several of them.
• The supervisory control of the plant will be exercised from operator stations in a central control room.
• Communication networks are used to facilitate the process of interaction. The workload for process control is distributed as a result of the use of many microcomputers.
• Several computers allow for parallel multitasking, which is possible.
• Because of networking and the low level of control cabling, the process data can be sent throughout the plant.

4. Numerical control and robotics :

• Another sort of industrial computer control is numerical control, in which a machine tool is guided through a series of processing stages.
• There will be a set of written instructions that outline the order and specifics of each procedure.
• This kind of computer control would place the tool being used in a procedure in an improved position.

5. Programmable logic control (PLC) :

• Discrete control is typically carried out using this kind of computer control.
• Control is straightforward and continuous.
• The emergency shut-down function is available, and the response time is very short.
• This microprocessor-based control can perform logic, sequencing, timing, counting, and arithmetic control operations in a process or in a machine. It can store instructions in programmable memory.
• In the process sectors as well as the discrete product industries, a PLC can perform continuous and discrete process control.

6. Supervisory control :

• A controller would be used to do data collecting, display, and analysis in this type of control system.
• The controller’s settings can be modified via the computer.
• The computer would perform supervisory functions, while the local controller would perform controlling operations.
• This form of control system can optimize the process’s operating conditions.
• It would also divide the limited resources between the parallel processes.
• The operator can remotely determine the plant condition with the help of a supervisory control system.

Advantages of computer process control

• Maintains the plant’s environment and responds rapidly to plant concerns
• It would serve to coordinate the system.
• It is possible to boost production.
• The plant’s dependability will be improved.
• It would plan the production.
• Maintenance is reduced.

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