RU2788818C1 - Proportional-integral-differential controller with deviation adders - Google Patents

Abstract

FIELD: automatic controllers.

SUBSTANCE: invention relates to automatic controllers that implement a proportional-integral-differential control law, and can be used to control any technological objects that have parameter drift and are subject to uncontrolled disturbances. The PID controller includes at least two series-installed deviation adders, each of which consists of an input signal limiter, a multiplier, an output signal limiter and an adder connected in series, while the input signal limiter is configured to set the operating range of the deviation adder, the block multiplication is configured to calculate an additional control action on the actuator, the output signal limiter is configured to prevent an excessive output signal, and the adder is configured to sum the output signal of the deviation adder of the previous operating range with the output signal from the output signal limiter of the operating range deviation adder.

EFFECT: expanding the boundaries of stability and functionality of the controller.

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Description

The invention relates to automatic controllers that implement a proportional-integral-differential control law, and can be used to control any technological objects that have parameter drift and are subject to uncontrolled disturbances.

A proportional-integral-differential controller is known, containing a comparison block, a control object setting block, multiplication blocks, proportional blocks, limiters, adders, a module definition block, a non-linear block with a dead zone, a differentiator, a key, an integrator, an OR element (No. 2234116, G05B 11/36, published on August 10, 2004, Bulletin No. 22).

The disadvantage of this PID controller is the complexity of the design and insufficient speed and accuracy of control of technological processes.

Also known is a PID controller containing an integrator, a differentiator, three adders, a nonlinear limiter, two relay elements, a parameter switch, three OR elements and a divider (No.

The disadvantage of this controller is the low quality of regulation and a limited region of stability when the parameters of the object drift with delay and the action of the system of perturbations at the input. The known regulator is focused on protecting the output signal from saturation due to the deterioration of the regulation rate.

The main objective of the invention is to improve the quality of regulation.

EFFECT: expanding the boundaries of stability and functionality of the controller.

The specified technical result is achieved by a proportional-integral-differential controller, including at least two series-installed deviation adders, each of which consists of an input signal limiter, a multiplication unit, an output signal limiter, and an adder connected in series, while the input limiter signal is configured to set the operating range of the deviation adder, the multiplication unit is configured to calculate an additional control action on the actuator, the output signal limiter is configured to prevent excessive output signal, and the adder is configured to sum the output signal of the deviation adder of the previous operating range with the output signal from the limiter of the output signal of the operating range deviation adder.

In FIG. 1 shows a block diagram of a PID controller with deviation adders.

The device contains a standard PID controller 1 and, depending on the complexity of the technological process, deviation adders A, B, C, D, E installed in series, while at least two of them can be installed to implement the invention. Each of the deviation adders A, B, C, D, E consists of a series-connected input signal limiter 2, 6, 10, 14, 18, respectively, which sets the operating range of the deviation adder, multiplication block 3, 7, 11, 15, 19, respectively, with which the control action is calculated, the output signal limiter 4, 8, 12, 16, 20, respectively, designed to prevent excessive output signal, and the adder 5, 9, 13, 17, 21, respectively, with which summation of the output signal of the previous adder with the output signal from the limiter of the output signal of the operating range deviation adder. The deviation adder A is a zero adder and is intended for proactive action on the regulatory body when the sign of the mismatch Δ changes. Deviation totalizer B is a minimum deviation totalizer and is designed to operate within the minimum deviation range. Deviation totalizer C operates in the medium deviation range, deviation totalizer D in the high deviation range, and deviation totalizer E in the critical deviation range.

The device works as follows.

PID controller 1 received a deviation signal. According to the control law, a signal OP is generated, which enters the deviation adder A, operating at a minimum deviation Δ, which is set in the input signal limiter 2 with the parameter Δ0LIM. If the error signal Δ exceeds the range setting Δ0LIM (input signal limiter 2), then a signal Δ0 equal to the difference between /Δ/ and Δ0LIM is generated.

When the sign of the deviation changes, the control signal OP0 is generated in the multiplication block 3 according to the formula:

,

,

where K0 is the signal amplification factor.

The control signal OP0 then goes to output limiter 4. The output limit is set by parameter OP0LIM.

The generated signal OP0 from the output signal limiter 4 is fed to the input of the adder 5, in which the control actions OP (output signal from the PID controller 1) and OP0 are summed, and the OPA signal is generated at the output.

With a further increase in the error signal Δ, the deviation adder B comes into operation. If the error signal Δ is less than Δ1LIM, then a zero signal value is formed, that is, OP1=0. If the error signal Δ exceeds the range setting Δ1LIM (input signal limiter 6), then a signal Δ1 equal to the difference between /Δ/ and Δ1LIM is generated. Further, in the multiplication block 7, the control action OP1 is calculated according to the formula:

,

,

where K1 is the signal gain.

To avoid excessive action on the regulator, an output signal limiter 8 is used, the output limit is set by parameter OP1LIM.

The generated signal OP1 from the output signal limiter 8 is fed to the input of the adder 9, in which the control actions OPA and OP1 are summed, and the OPB signal is generated at the output.

With a further increase in the error signal Δ, the adder C comes into operation. If the error signal Δ is less than Δ2LIM, then a zero signal value is formed, that is, OP2=0. If the error signal Δ exceeds the range setting Δ2LIM (output signal limiter 10), then a signal Δ2 is generated equal to the difference between /Δ/ and Δ2LIM. Further, in the multiplication block 11, the control action OP2 is calculated according to the formula:

,

,

where K2 is the signal amplification factor.

To exclude excessive action on the regulator, an output signal limiter 12 is used, the output limit is set by parameter OP2LIM.

The generated signal OP2 from the output signal limiter 12 is fed to the input of the adder 13, in which the control actions OPB and OP2 are summed, and the OPC signal is generated at the output.

With a further increase in the error signal Δ, the deviation adder D comes into operation. If the error signal Δ is less than Δ3LIM, then a zero signal value is formed, that is, OP3=0. If the error signal Δ exceeds the range setting Δ3LIM (input signal limiter 14), then a signal Δ3 is generated equal to the difference between /Δ/ and Δ3LIM. Further, in the multiplication block 15, the control action OP3 is calculated according to the formula:

,

,

where K3 is the signal gain.

To exclude excessive action on the regulator, an output signal limiter 16 is used, the output limit is set by parameter OP3LIM.

The generated signal OP3 from the input signal limiter 16 is fed to the input of the adder 17, in which the control actions OPC and OP3 are summed, and the OPD signal is generated at the output.

With a further increase in the error signal Δ, the deviation adder E enters into operation. If the error signal Δ is less than Δ4LIM, then a zero signal value is formed, that is, OP4=0. If the error signal Δ exceeds the range setting Δ4LIM (input signal limiter 18), then a signal Δ4 equal to the difference between /Δ/ and Δ4LIM is generated. Further, in the multiplication block 19, the control action OP4 is calculated according to the formula:

,

,

where K4 is the signal amplification factor.

An output limiter 20 is used to avoid excessive action on the regulator, the output limit is set by parameter OP4LIM.

The generated signal OP4 from the output signal limiter 20 is fed to the input of the adder 21, in which the control actions OPD and OP4 are summed, and the OPE signal is generated at the output.

The total control signal OPE from the deviation adders A, B, C, D, E and from the PID controller is sent to the actuator 22 and is calculated by the following formula:

The proposed PID controller with deviation adders can be implemented on elements of digital and microprocessor technology.

Claims (1)

Proportional-integral-derivative controller, including at least two series-installed deviation adders, each of which consists of a series-connected input signal limiter, multiplication unit, output signal limiter and adder, while the input signal limiter is configured to set the operating range of the deviation adder, the multiplication unit is configured to calculate an additional control action on the actuator, the output signal limiter is configured to prevent an excessive output signal, and the adder is configured to sum the output signal of the deviation adder of the previous operating range with the output signal from the output signal limiter of the operating deviation adder range.

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