A forward advance observation device and system for process signals

Abstract

The present invention discloses a forward advance observation device and system for a process signal, which performs forward observation of the process signal through a positive feedback device, an integrator limiter controller, an integrator, a differentiator, and a forward output controller, integrates and superimposes the input process signal through the positive feedback device, the integrator, and the integrator limiter controller, and processes the superimposed signal through the differentiator and the forward output controller, thereby finally realizing the forward observation of the process signal. The present invention improves the efficiency of the forward advance observation of the process signal through the arrangement of the positive feedback device, the integrator limiter controller, the integrator, the differentiator, and the forward output controller, thereby facilitating beneficial adjustments to the industrial control system according to the results obtained by the forward advance observation, and improving the control performance.

Description

Technical Field

[0001] The invention relates to the field of industrial processes, and in particular to a forward advance observation device and system for process signals. Background Art

[0002] In the field of industrial process control, advance observation plays an important role in improving process control performance. Various advance observation methods have been formed over a long period of time, such as differentiators, PD controllers, phase lead correctors, and high-performance lead observers. In order to meet various different needs, advance observation methods need to be developed.

[0003] In the application of the advance observation method, the existing technology cannot meet the existing observation needs for the forward advance observation of the process signal. For example, the advance observation performance of the main steam pressure process signal in the main steam pressure control system of the thermal power unit is poor, which will affect the effect of suppressing the main steam pressure deviation.

[0004] Therefore, there is an urgent need for a forward advance observation device for process signals to solve the problem of low efficiency of forward advance observation of process signals. Summary of the invention

[0005] The embodiment of the present invention provides a forward advance observation device and system for a process signal, so as to improve the efficiency of the forward advance observation of the process signal.

[0006] In order to solve the above problems, an embodiment of the present invention provides a forward advance observation device for a process signal, comprising: a positive feedback device, an integrator limit controller, an integrator, a differentiator, and a forward output controller;

[0007] The integrator limit controller is connected to the integrator, one end of the integrator is connected to the input end of the positive feedback device, and the other end of the integrator is connected to the output end of the positive feedback device; the other output end of the positive feedback device is connected to one end of the differentiator; the other end of the differentiator is connected to one end of the forward output controller;

[0008] Among them, the positive feedback device is used to add the first superimposed signal processed by the integrator to the first input signal after receiving each first input signal to obtain a second superimposed signal, and send the second superimposed signal to the differentiator and the integrator; and the first input signal corresponding to the second superimposed signal is separated by a preset time from the second input signal corresponding to the first superimposed signal. If the first input signal is an initial signal, the first superimposed signal processed by the integrator is 0.

[0009] As an improvement of the above solution, the integrator also satisfies the following conditions:

[0010]

[0011] Where I(s) is the transfer function of the integrator; T I is the integration time constant in seconds; s is the Laplace operator.

[0012] As an improvement of the above solution, the integrator limiter controller is used to limit the output signal of the integrator, and also meets the following conditions:

[0013]

[0014] Where, I(t) is the integrator output signal, PV IN (t) is the input signal, T I is the integration time constant, in seconds; and PV IN (t) is the high limit value of the integrator limit controller, and 0 is the low limit value of the integrator limit controller.

[0015] As an improvement of the above solution, the integrator limiter controller is used to limit the output signal of the integrator, specifically:

[0016] When the output signal of the integrator is greater than 0, the output signal of the integrator is less than the input signal, and the input signal is greater than 0, the output signal of the integrator is:

[0017]

[0018] When the output signal of the integrator is greater than the input signal and the input signal is greater than 0, the output signal of the integrator is:

[0019] I(t)=PV IN (t);

[0020] When the input signal is less than 0, the output signal of the integrator is:

[0021] I(t)=0;

[0022] Where, I(t) is the integrator output signal, PV IN (t) is the input signal, T I is the integration time constant, in seconds; and PV IN (t) is the high limit value of the integrator limit controller, and 0 is the low limit value of the integrator limit controller.

[0023] As an improvement of the above solution, the differentiator also satisfies the following conditions:

[0024]

[0025] Where D(s) is the transfer function of the differentiator, is the gain of the differentiator, and the unit is dimensionless; TD is the differential time constant in seconds; s is the Laplace operator.

[0026] As an improvement of the above solution, the forward output controller also satisfies the following conditions:

[0027]

[0028] Where DOC(t) is the output signal of the forward output controller and D(t) is the output signal of the differentiator.

[0029] Correspondingly, an embodiment of the present invention further provides a forward advance observation system for a process signal, comprising: a collection device, a forward advance observation device for a process signal, and a target control system; wherein the collection device is connected to the target control system and the forward advance observation device for the process signal, respectively, and the forward advance observation device for the process signal is connected to the target control system; and the forward advance observation device for the process signal is applied to the forward advance observation device for the process signal as described in the present invention;

[0030] The acquisition device is used to acquire input signals of the target control system and send the input signals to the forward advance observation device of the process signal;

[0031] The forward advance observation device of the process signal is used to obtain an output signal through advance observation according to the input signal, and send the output signal to the target control system;

[0032] The target control system is used to generate corresponding control instructions according to the output signal, so as to control the corresponding device according to the control instructions.

[0033] Correspondingly, an embodiment of the present invention also provides a computer-readable storage medium, which includes a stored computer program, wherein when the computer program is running, the device where the computer-readable storage medium is located is controlled to execute the control method executed by the positive feedback device, integrator limiting controller, integrator, differentiator and forward output controller described in the present invention.

[0034] As can be seen from the above, the present invention has the following beneficial effects:

[0035] The present invention provides a forward advance observation device for a process signal, which performs forward observation of the process signal through a positive feedback device, an integrator limiter controller, an integrator, a differentiator, and a forward output controller, integrates and superimposes the input process signal through the positive feedback device, the integrator, and the integrator limiter controller, and processes the superimposed signal through the differentiator and the forward output controller, and finally realizes the forward observation of the process signal. The present invention improves the efficiency of the forward advance observation of the process signal through the arrangement of the positive feedback device, the integrator limiter controller, the integrator, the differentiator, and the forward output controller, so as to facilitate the beneficial adjustment of the industrial control system according to the result obtained by the forward advance observation, and improve the control performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a structural schematic diagram of a forward advance observation device for process signals provided by an embodiment of the present invention;

[0037] Figure 2 is a schematic structural diagram of a forward advance observation device for process signals provided by another embodiment of the present invention;

[0038] Figure 3 It is a schematic diagram of experimental results of a forward advance observation device for process signals provided by an embodiment of the present invention;

[0039] Figure 4 It is a schematic diagram comparing experimental results of a forward advance observation device for process signals provided by an embodiment of the present invention and a conventional advance observation device;

[0040] Figure 5 It is a schematic diagram of the structure of a forward advance observation system for process signals provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0041] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] Embodiment 1

[0043] See also Figure 1 , Figure 1 FIG. 1 is a schematic diagram of a forward advance observation device for a process signal provided by an embodiment of the present invention. Figure 1 As shown, this embodiment includes: a positive feedback device 101, an integrator limit controller 102, an integrator 103, a differentiator 104 and a forward output controller 105;

[0044] The integrator limit controller 102 is connected to the integrator 103, one end of the integrator 103 is connected to the input end of the positive feedback device 101, and the other end of the integrator 103 is connected to the output end of the positive feedback device 101; the other output end of the positive feedback device 101 is connected to one end of the differentiator 104; the other end of the differentiator 104 is connected to one end of the forward output controller 105;

[0045] Among them, the positive feedback device 101 is used to add the first superimposed signal processed by the integrator 103 to the first input signal after receiving each first input signal to obtain a second superimposed signal, and send the second superimposed signal to the differentiator 104 and the integrator 103; and the first input signal corresponding to the second superimposed signal is separated by a preset time from the second input signal corresponding to the first superimposed signal. If the first input signal is an initial signal, the first superimposed signal processed by the integrator 103 is 0.

[0046] In a specific embodiment, the input signal is a deviation signal between a main steam pressure set signal and a main steam pressure signal of a main steam pressure control system of a thermal power unit.

[0047] In a specific embodiment, since the output signal obtained by the integrator after processing the superimposed signal has a divergence problem, the integrator limiter controller is used to limit the amplitude of the integrator output signal output by the integrator.

[0048] In a specific embodiment, the integrator is used to accelerate the superposition signal.

[0049] In a specific embodiment, the differentiator is used to convert the rising trend and the falling trend of the superimposed signal output by the positive feedback device into positive signal and negative signal output respectively.

[0050] In a specific embodiment, the positive output controller is used to extract the positive signal of the output signal processed by the differentiator and exclude the negative signal of the output signal processed by the differentiator.

[0051] As an improvement of the above solution, the integrator also satisfies the following conditions:

[0052]

[0053] Where I(s) is the transfer function of the integrator; T I is the integration time constant in seconds; s is the Laplace operator.

[0054] As an improvement of the above solution, the integrator limiter controller is used to limit the output signal of the integrator, and also meets the following conditions:

[0055]

[0056] Where, I(t) is the integrator output signal, PV IN (t) is the input signal, T I is the integration time constant, in seconds; and PV IN (t) is the high limit value of the integrator limit controller, and 0 is the low limit value of the integrator limit controller.

[0057] As an improvement of the above solution, the integrator limiter controller is used to limit the output signal of the integrator, specifically:

[0058] When the output signal of the integrator is greater than 0, the output signal of the integrator is less than the input signal, and the input signal is greater than 0, the output signal of the integrator is:

[0059]

[0060] When the output signal of the integrator is greater than the input signal and the input signal is greater than 0, the output signal of the integrator is:

[0061] I(t)=PV IN (t);

[0062] When the input signal is less than 0, the output signal of the integrator is:

[0063] I(t)=0;

[0064] Where, I(t) is the integrator output signal, PV IN (t) is the input signal, T I is the integration time constant, in seconds; and PV IN (t) is the high limit value of the integrator limit controller, and 0 is the low limit value of the integrator limit controller.

[0065] As an improvement of the above solution, the differentiator also satisfies the following conditions:

[0066]

[0067] Where D(s) is the transfer function of the differentiator, is the gain of the differentiator, and the unit is dimensionless; T D is the differential time constant in seconds; s is the Laplace operator.

[0068] As an improvement of the above solution, the forward output controller also satisfies the following conditions:

[0069]

[0070] Where DOC(t) is the output signal of the forward output controller and D(t) is the output signal of the differentiator.

[0071] In a specific embodiment, to better illustrate the processing flow of the forward advance observation device, see Figure 2 , including: a differential device 201, a forward output control device 202, an integral device 203, an integral device limit control device 204 and a positive feedback link 205: when the first input signal enters the positive feedback link 205 (i.e. the positive feedback device described in the present application), a signal accumulation algorithm is performed with the positive feedback signal after the previous integration to obtain a first positive feedback signal, and the first positive feedback signal is transmitted to the integral device 203 (i.e. the integrator described in the present application) and the differential device 201 (i.e. the differentiator described in the present application): after the integral device 203 integrates the first positive feedback signal, when the second input signal enters the positive feedback link 205, the integrated first positive feedback signal is added to the second input signal to obtain a second positive feedback signal; after the differential device 201 differentiates the first positive feedback signal, a first differential signal is obtained, and the first differential signal is transmitted to the forward output control device 202 for positive signal screening, thereby obtaining an advanced observation signal of the first input signal.

[0072] In a specific embodiment, the interval between receiving the first input signal and the second input signal may be 1 second.

[0073] In a specific embodiment, the accumulation algorithm is specifically as follows: the nth second input signal and the positive feedback signal output by the n-1th second integrator are added in the positive feedback link, and then input into the differentiator for differentiation, and the signal obtained after differentiation is transmitted to the forward output control device for processing, so as to obtain the lead observation signal of the nth second input signal; at the same time, the signal after addition in the positive feedback link will be input into the integrator again for processing, and superimposed with the n+1th second input signal (it should be noted that when the input signal is the first second input signal, the integrator output signal added in the positive feedback link and the first second input signal is 0).

[0074] In a specific embodiment, to better illustrate the present embodiment, a process forward lead observation PFLO is performed on the process output signal of a fourth order inertia process (FOIP) at a unit step input, wherein the fourth order inertia process FOIP is:

[0075]

[0076] Where FOIP(s) is the transfer function of the fourth-order inertial process FOIP, T FOIP is the FOIP time constant, in s;

[0077] In this embodiment, the parameters of FOIP(s) are: T I =100s, T D =100s, K D =4, T FOIP = 100s, FOIP input is a unit step signal, and the experimental results of the forward advance observation of the PFLO output during the FOIP process output signal are obtained, such as Figure 3 Shown: In Figure 3 In the middle, the dotted line PV FOIP (t) is the process output signal of the fourth-order inertial process FOIP at a unit step input, and the solid line PV PFLO (t) is the process output signal of the process forward lead observer PFLO. It can be seen that the process output signal of PFLO is significantly ahead of the process output signal of FOIP, which plays the role of leading observation of the forward process signal.

[0078] In a specific embodiment, for better explanation, see Figure 4 , Figure 4 A schematic diagram comparing experimental results of a forward advance observation device for process signals provided by an embodiment of the present invention and a conventional advance observation device is shown as follows:

[0079] Under the same parameter settings, the process output signal of FOIP (fourth-order inertial process) at unit step input is subjected to PFLO (positive lead observation device of process signal) and common differentiator (Common Differentiator, CD for short; parameter settings: T D =100s, K D =2) and compare the advance observation effects of the two:

[0080] like Figure 4 It can be seen that PV PFLO (t) is the process output signal of the process forward lead observer PFLO, PV CD (t) is the process output signal of the commonly used differentiator CD. It can be seen that the process output signal of PFLO is significantly ahead of the process output signal of CD, which means that PFLO effectively improves the efficiency of advance observation of process signals.

[0081] Accordingly, for a better explanation, see Figure 5The present invention also provides a forward advance observation system for a process signal, comprising: an acquisition device 501, a forward advance observation device 502 for a process signal and a target control system 503; wherein the acquisition device 501 is connected to the target control system 503 and the forward advance observation device 502 for the process signal respectively, and the forward advance observation device 502 for the process signal is connected to the target control system 503; and the forward advance observation device 502 for the process signal is applied to the forward advance observation device 502 for the process signal as described in the present invention;

[0082] The acquisition device 501 is used to acquire the input signal of the target control system and send the input signal to the forward advance observation device of the process signal;

[0083] The forward advance observation device 502 of the process signal is used to obtain an output signal through advance observation according to the input signal, and send the output signal to the target control system;

[0084] The target control system 503 is used to generate corresponding control instructions according to the output signal, so as to control the corresponding device according to the control instructions.

[0085] In addition, an embodiment of the present invention also provides a computer-readable storage medium, which includes a stored computer program, wherein when the computer program is running, the device where the computer-readable storage medium is located is controlled to execute the control method performed by the positive feedback device, integrator limiting controller, integrator, differentiator and forward output controller described in any of the above embodiments.

[0086] Wherein, if the module / unit integrated by the forward advance observation device of the process signal involved in the present invention is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, the control method performed by the positive feedback device, integrator limiter controller, integrator, differentiator and forward output controller described in the present invention can also be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a computer-readable storage medium. When the computer program is executed by the processor, the steps of the above-mentioned various method embodiments can be implemented. Wherein, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form, etc. The computer-readable medium can include: any entity or device that can carry the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electrical carrier signal, telecommunication signal and software distribution medium, etc.

[0087] Implementing this embodiment has the following beneficial effects:

[0088] This embodiment performs forward observation of process signals through positive feedback devices, integrator limit controllers, integrators, differentiators, and forward output controllers, integrates and superimposes input process signals through positive feedback devices, integrators, and integrator limit controllers, and processes superimposed signals through differentiators and forward output controllers, thereby finally realizing advance observation of process signals. In the advance observation of the 4th-order inertial process FOIP signal, the obtained advance observation output signal is obviously more in line with the actual situation than the 4th-order inertial process FOIP signal, which can improve the efficiency of advance observation of process signals in industrial control systems, so that further industrial control operation adjustments can be made according to the results of the advance observation, which is conducive to improving the stability and safety of the industrial control system.

[0089] It should be noted that the device embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. In addition, in the accompanying drawings of the device embodiments provided by the present invention, the connection relationship between the modules indicates that there is a communication connection between them, which may be specifically implemented as one or more communication buses or signal lines. A person of ordinary skill in the art may understand and implement it without paying any creative effort.

[0090] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A forward advance observation device for process signals, It is characterized in that include: Positive feedback devices, integrator limiter controllers, integrators, differentiators, and forward output controllers; The integrator limit controller is connected to the integrator, one end of the integrator is connected to the input end of the positive feedback device, and the other end of the integrator is connected to the output end of the positive feedback device; the other output end of the positive feedback device is connected to one end of the differentiator; the other end of the differentiator is connected to one end of the forward output controller; The positive feedback device is used to add the first superimposed signal processed by the integrator to the first input signal after receiving each first input signal to obtain a second superimposed signal, and send the second superimposed signal to the differentiator and the integrator respectively; and the reception time interval between the first input signal corresponding to the second superimposed signal and the first input signal corresponding to the first superimposed signal is a preset time, and if the first input signal is an initial signal, the first superimposed signal processed by the integrator is 0; The integrator also satisfies the following conditions: Where I(s) is the transfer function of the integrator; T I is the integration time constant in seconds; s is the Laplace operator; The integrator limiter controller is used to limit the output signal of the integrator, and also meets the following conditions: Where, I(t) is the integrator output signal, PV IN (t) is the input signal, T I is the integration time constant, in seconds; and PV IN (t) is the high limit value of the integrator limit controller, and 0 is the low limit value of the integrator limit controller; The differentiator also satisfies the following conditions: Where D(s) is the transfer function of the differentiator, K D is the gain of the differentiator, unit is dimensionless; T D is the differential time constant in seconds; s is the Laplace operator; The forward output controller also satisfies the following conditions: Where DOC(t) is the output signal of the forward output controller and D(t) is the output signal of the differentiator.

2. The forward leading observation device for process signals according to claim 1, It is characterized in that The integrator limit controller is used to limit the output signal of the integrator, specifically: When the output signal of the integrator is greater than 0, the output signal of the integrator is less than the input signal, and the input signal is greater than 0, the output signal of the integrator is: When the output signal of the integrator is greater than the input signal and the input signal is greater than 0, the output signal of the integrator is: I(t)=PV IN (t); When the input signal is less than 0, the output signal of the integrator is: I(t)=0; Where, I(t) is the integrator output signal, PV IN (t) is the input signal, T I is the integration time constant, in seconds; and PV IN (t) is the high limit value of the integrator limit controller, and 0 is the low limit value of the integrator limit controller.

3. A forward advance observation system for process signals, It is characterized in that include: An acquisition device, a forward advance observation device for process signals and a target control system; wherein the acquisition device is connected to the target control system and the forward advance observation device for process signals respectively, and the forward advance observation device for process signals is connected to the target control system; and the forward advance observation device for process signals is applied to the forward advance observation device for process signals as described in any one of claims 1 to 2; The acquisition device is used to acquire input signals of the target control system and send the input signals to the forward advance observation device of the process signal; The forward advance observation device of the process signal is used to obtain an output signal through advance observation according to the input signal, and send the output signal to the target control system; The target control system is used to generate corresponding control instructions according to the output signal, so as to control the corresponding device according to the control instructions.

4. A computer-readable storage medium, It is characterized in that The computer-readable storage medium includes a stored computer program, wherein when the computer program is running, the device where the computer-readable storage medium is located is controlled to execute the control method executed by the positive feedback device, integrator limiting controller, integrator, differentiator and forward output controller as described in any one of claims 1 to 2.

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