In petroleum, chemical, metallurgy, electric power, light industry and building materials and other industrial production of continuous or according to a certain program cycle of automatic control of the production process called production process automation. Production process automation is an important means to maintain production stability, reduce consumption, reduce costs, improve working conditions, promote civilized production, ensure production safety and improve labor productivity. It is the characteristic of scientific and technological progress in the 20th century and the symbol of industrial modernization.
The automatic control of a certain or some physical parameters of the production process is called process control by using analog or digital control. Process control systems can be divided into conventional instrument process control systems and computer process control systems. Along with the industrial production scale to large, complex, fine, mass, rely on instrument control system has been difficult to meet the production and management requirements, computer process control system is developed in recent decades to take the computer as the core control system.
Process control is widely used in petroleum, chemical, electric power, metallurgy and other departments. In the 1950s, process control was mainly used to keep some parameters in the production process unchanged, so as to ensure stable output and quality. In the 1960s, with the emergence of various combination instruments and itinerant detection devices, process control has begun to transition to centralized monitoring, operation and control. In 1970s, a multilevel computer control system combining process control optimization and management scheduling automation appeared.