ADAPTIVE TUNING METHOD FOR A DIGITAL PID CONTROLLER

摘要

The aim of the invention is that of rapid automatic tuning of a digital proportional-integral-derivative controller (PID controller) by means of the acknowledgement from an analogue sensor in order to automate technological processes using programmable logic controllers (PLC). This aim is achieved by implementing calculation formulas for calculating the tuning step and the tuning rate for each of three parameters K_p, K_i, K_d of a digital PID controller in a closed control loop using negative feedback. The parameters of the PID controller are tuned in a temporally offset manner, i.e. independently for the individual parameters. In order to adjust each individual parameter of a digital PID controller, three mathematical equations are used which require a minimal increase in PLC calculation loading. The PID control parameters are tuned once during startup. Thereafter, the PID controller uses the ascertained parameters for controlling the technological process. The invention allows universal use, i.e. it is not linked to a particular type of closed-loop control system.