Active Disturbance Rejection Control System and Control Method for First-Order Pure Delay Objects

Abstract

The invention provides an active disturbance rejection control system and a control method for a first-order pure lag object. The active disturbance rejection control system comprises a control signal storage. The active disturbance rejection control system and the control method have the advantages that a control input variable of the controlled object can be acquired by the control signal storage, can be stored in the control signal storage, is delayed by preset time and then is outputted to an expanded state observer, so that an output variable of the controlled object does not correspond to the control input variable of a previous moment under the condition that lag of the output variable of the controlled object can be compensated; two input variables (the output variable of the controlled object and the control input variable of the previous moment) received by the expanded state observer can accurately correspond to each other, time directions of the two input variables of the expanded state observer can be unified, accordingly, the observation precision is improved, a closed-loop control effect is greatly improved, and active disturbance rejection control is stable and can be accurately performed on the first-order pure lag object.

Description

technical field [0001] The invention relates to the technical field of industrial control systems, in particular to a first-order pure lagging object active disturbance rejection control system and a control method thereof. Background technique [0002] In the actual control system of the factory, there are thousands of control loops, but most of them are single loops. Most of these single-loop control objects can be described by the first-order plus pure lag model. There are many practical examples of first-order pure lag objects in industrial sites, such as first-order water tank or tank flow level objects, pipeline valves-flow objects, fuel-temperature objects during heating, cold water flow-temperature during coil heat exchange objects as well as first-order RC circuits and more. In addition, after splitting many complex systems, the final result is also first-order plus pure lag objects. If we start from the operation of the control system, we find that most of the d...

AI Technical Summary

Problems solved by technology

From two aspects, first, rapidity and overshoot cannot be well unified. For an actual system, we often hope that under the action of the controller, it can achieve the control goal "fast and well", but PID Controllers are contradictory on this point

If quickness is the priority, so that the time to reach the target is as short as possible to meet the "fast" requirement, usually, there will be a large overshoot, which is not allowed in many industrial sites and may damage the equipment. If the priority is overshoot Requirements to meet "good", although this can make the system overshoot small, achieve the control target smoothly, but often at the cost of sacrificing more transition time, in short, it is necessary to make a trade-off and trade-off between "fish and bear's paw"

Second, if there is pure lag, the control effect of PID will be greatly reduced or even invalid

Such time misalignment will bring serious consequences, making the observation value of the expansion state device inaccurate, which will mislead the feedback control rate, resulting in poor or even unstable control effect

Images