PID control parameter setting method based on stability margin and dynamic response index

Abstract

The invention relates to the field of PID control, in particular to a PID control parameter setting method based on stability margin and a dynamic response indexes. The PID control parameter setting method comprises the following steps of: calculating to obtain the stability margin of a closed loop control system; calculating to obtain PID control parameters according to the stability margin of the closed loop control system; performing closed-loop control system step response simulation according to the PID control parameters, and acquiring the dynamic response index through using a step response curve so as to indirectly associate the stability margin with the dynamic response index; and on the basis of an association mode of the stability margin and the dynamic response index, searchingthe stability margin to obtain an optimal solution of the optimization problem so as to set the PID control parameter. By using the PID control parameter setting method, the following effects can beachieved: the PID control parameters and the dynamic response performance indexes are associated, so that the user friendliness is improved; and the used gridding search optimization can directly givean optimal solution meeting the dynamic performance requirement of the user, so that the setting efficiency is improved, and repeated setting is avoided.

Description

technical field [0001] The invention relates to the field of PID control, in particular to a PID control parameter tuning method based on a stability margin and a dynamic response index. Background technique [0002] Proportional-integral-derivative (PID) control is one of the most common and effective control methods in the field of industrial process control. According to statistics, more than 90% of automatic control loops adopt PID control strategy. The advantages of PID control are: simple structure, good stability, safety and reliability, and easy adjustment. [0003] At present, the widely used PID parameter tuning methods mainly include data-driven tuning methods and model-based tuning methods. For data-driven parameter tuning methods, the performance of closed-loop control cannot be estimated more accurately in advance, so the tuning strategy cannot be adjusted according to the actual dynamic response requirements; Feature extraction, such as: Z-N method, critica...

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Problems solved by technology

However, the methods listed above cannot associate the tuning parameters with specific closed-loop dynamic response indicators, so users have no expectations for closed-loop control performance during the parameter tuning process

Although the user can adjust the parameters after tuning, the adjustment process cannot fully guarantee the stability of the closed-loop control system

Especially when there are a large number of PID loops that need to be tuned, for example, during the start-up stage of the device or after the working conditions change, it is difficult for technicians to have time to fine-tune the parameters of each loop until better control performance occurs. Once the adjustment range is too large , may lead to instability of the control system

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