CN104238356A - Observation method based on extended state observer for time delay system - Google Patents

Abstract

The invention discloses an observation method based on an extended state observer for a time delay system. The observation method includes inputting the output quantity y of a controlled target into the extended state observer directly, inputting the control quantity u into a delayer, and inputting the control quantity u which is delayed by the time delayer into the extended state observer until the time of the control quantity u delayed by the delayer is equal to the delay quantity of the time delay system. Therefore, synchronization of the control quantity and the output quantity of the controlled object when being input into the extended state observer is achieved, and the observer has better observation result. The observation method is easy, feasible and effective.

Description

Observation method of time-delay system by extended state observer

technical field

The invention relates to the technical field of electricity, in particular to an observation method of a time-delay system by an extended state observer.

Background technique

The extended state observer is used to observe both the unknown disturbance and the state quantity of the system, and the controller compensates the observed unknown disturbance, which can improve the control effect. But in dealing with the time-delay system, the current method has big problems. We know that there are two quantities entering the expanded state observer, one is the control quantity and the other is the output quantity of the controlled object. These two quantities must enter into it synchronously, otherwise there will be inaccurate observations and even divergence of the entire controller. However, the characteristic of the time-delay system is that the output quantity of the controlled object lags behind the control quantity. The lag time is the time delay of a time-delay system. This makes the input and output of the expanded state observer asynchronous. Slight asynchrony will cause inaccurate observation results and reduce the control precision of the control system. Serious asynchrony will cause the control system to diverge.

Contents of the invention

The purpose of the present invention is: provide a kind of extended state observer to the observation method of time-delay system, it can solve the shortcoming that extended state observer is inaccurate to the observation of time-delay system, makes extended state observer more accurate to time-delay system observations to overcome the deficiencies of existing technologies.

The present invention is realized in this way: the observation method of the time-delay system by the extended state observer, the output quantity y of the controlled object directly enters the extended state observer, and the control variable u first enters the hysteresis device, and the hysteresis makes the control quantity u The lag time is equal to the lag of the time-delay system, and then let the control variable u through the hysteresis device enter the expansion state observer, thus indirectly realizing the synchronization of the control variable and the output quantity.

Due to the adoption of the above-mentioned technical scheme, compared with the prior art, the present invention uses the control variable of the controlled object to lag through the hysteresis device, and then enters the expansion state observer, so that the control variable and the output value of the controlled object can be realized. When entering the expanded state observer is the purpose of synchronization, so that the observer will obtain better observation results. The invention is simple and easy to implement, and has good application effect.

Description of drawings

Accompanying drawing 1 is principle flowchart of the present invention;

In Figure 1, b ₀ is the amplification factor of the control quantity u , which is an inherent parameter of the extended state observer and has nothing to do with the processing.

Detailed ways

Embodiment of the present invention: the observation method of the time-delay system by the extended state observer, the output quantity y of the controlled object directly enters the extended state observer, and the control quantity u first enters the hysteresis device, and the hysteresis makes the control quantity u lag The time is equal to the lag of the time-delay system, and then let the control variable u through the lag device enter the expansion state observer, thus indirectly realizing the synchronization of the control variable and the output quantity.

The parameters are explained as follows: the control cycle of the controller is T, and the lag of the time-delay system is τ. In practice, τ is greater than T. Let the quotient of τ divided by T be equal to N. First, the control variable u is multiplied by b ₀ to obtain the two The product ub ₀ , and ub ₀ is the input of the time-delay, the output of the time-delay is u' . At the same time, u' is an input quantity of the extended state observer, and the other input quantity is the output quantity y of the controlled object; the specific realization of the hysteresis is as follows: first open up N+1 variables: u ₁ ~u _N and u' , The initial values of these variables are all equal to zero; u' = u _N ; u _N = u _N-1 ; u _N-1 = u _N-2 ;... u ₂ = u ₁ ; u ₁ = u ; After doing so the variable u ' will lag behind u for a period of time, and this period of time is exactly equal to τ; in this way, the purpose of making the control variable u and the output quantity y of the controlled object be synchronized when they enter the expanded state observer is realized. Once they are synchronized, then The observer will obtain better observation results.

Claims (1)

1. extended state observer is to an observation procedure for time lag system, it is characterized in that: by the output quantity of controlled device ydirectly enter extended state observer, and allow controlled quentity controlled variable ufirst enter delayed device, delayed device is by controlled quentity controlled variable uthe delayed time equals the delayed of time lag system, and then allows the controlled quentity controlled variable through delayed device uenter extended state observer, so indirectly achieve the synchronous of controlled quentity controlled variable and output quantity.