JP6399691B2 - Rotational speed control device, rotational speed control method, and rotational drive system - Google Patents

Description

  The present invention relates to a rotation speed control device, a rotation speed control method, and a rotation drive system.

  2. Description of the Related Art Conventionally, there has been disclosed an internal combustion engine control device in which an integral calculation unit calculates an operation amount of a control valve and outputs the operation amount to an internal combustion engine via a limiter (see Patent Document 1). The technique of Patent Literature 1 includes an anti-windup unit that prevents the occurrence of windup even when the target value of the control amount changes after the operation amount of the control valve is limited by the limiter.

JP2013-11173A

  In Patent Document 1, when a transitional change is given to an object to be controlled, there is a problem that an output value of an integral calculation unit having upper and lower limiters is saturated to an upper and lower limit value, resulting in a slow response speed. On the other hand, if the response speed is to be increased, it is necessary to widen the upper and lower limiter values of the integral calculation unit and adjust the gain of the PID control unit, which requires time and labor for adjustment. For this reason, priority is given to a decrease in the amount of windup, and the response time may be shortened.

  The present invention has been proposed in view of such circumstances, and the rotational speed control capable of preventing the wind-up phenomenon of the controlled object and reducing the transient response time without requiring time-consuming adjustment. An object is to provide a device, a rotation speed control method, and a rotation drive system.

  A first embodiment of the rotational speed control device according to the present invention is calculated by a computing means for computing a rotational speed deviation that is a deviation between a target rotational speed to be controlled and an actual rotational speed of the controlled object, and the computing means. A differential correction amount calculating means for calculating a differential correction amount based on the rotational speed deviation, a proportional correction amount calculating means for calculating a proportional correction amount based on the rotational speed deviation calculated by the calculating means, and the calculating means. An integral correction amount calculating means for calculating an integral correction amount based on the calculated rotational speed deviation; and when the integral correction amount calculated by the integral correction amount calculating means exceeds an upper limit value, the integral correction amount is set to the upper limit value. When the integral correction amount falls below the lower limit value, the integral correction amount is limited to the lower limit value and output, and when the integral correction amount is not less than the lower limit value and not more than the upper limit value. Is the integral correction And the proportional correction amount calculating means when the absolute value of the rotational speed deviation exceeds a predetermined value and the integral correction amount is limited by the integral correction amount limiting means. Limit value expanding means for expanding the upper limit value and lower limit value of the integral correction amount limiting means, the differential correction amount calculated by the differential correction amount calculating means, and the proportional correction amount. Adding means for adding the proportional correction amount calculated by the calculating means and the integral correction amount output from the integral correction amount limiting means, and outputting a control signal for controlling the rotational speed of the controlled object. It is characterized by that.

  In a second embodiment of the rotational speed control device according to the present invention, in the first embodiment, the limit value expanding means adds an expansion width that increases with an increase in the proportional correction amount to the upper limit value. The upper limit value is expanded, and the lower limit value is expanded by subtracting the expansion width from the lower limit value.

  According to a third embodiment of the rotational speed control device of the present invention, in the first or second embodiment, the limit value expanding means is configured such that the absolute value of the rotational speed deviation is equal to or less than a predetermined value, or When the integral correction amount is not limited by the integral correction amount limiting means, the upper limit value and the lower limit value are set to initial values before enlargement.

  A fourth embodiment of the rotational speed control device according to the present invention is characterized in that, in any one of the first to third embodiments, the control object is a rotating shaft that rotates a propulsion device of a ship.

  An embodiment of the rotational speed control method according to the present invention calculates a rotational speed deviation that is a deviation between a target rotational speed to be controlled and an actual rotational speed of the controlled object, and based on the calculated rotational speed deviation, A differential correction amount, a proportional correction amount, and an integral correction amount are respectively calculated, and when the absolute value of the rotation speed deviation exceeds a predetermined value and the integral correction amount is saturated, the calculated proportional correction amount is calculated. Accordingly, the upper limit value and the lower limit value of the integral correction amount are expanded, and when the calculated integral correction amount exceeds the expanded upper limit value, the integral correction amount is limited to the upper limit value and output, When the integral correction amount falls below the enlarged lower limit value, the integral correction amount is limited to the lower limit value and output, and the integral correction amount is not less than the enlarged lower limit value and not more than the enlarged upper limit value. Output the integral correction amount as it is, Has been differential correction amount, the computed proportional correction amount and by adding the outputted integral correction amount, and outputs a control signal for controlling the rotation speed of the control object.

  An embodiment of the rotational drive system according to the present invention detects any one of the first to fourth embodiments of the rotational speed control device according to the present invention and an actual rotational speed of a control target used in the rotational speed control device. It is characterized by comprising detection means and rotation drive means for rotating the control object based on a control signal output from the rotation speed control device.

  According to the present invention, it is possible to prevent the wind-up phenomenon of the controlled object and shorten the transient response time without making a troublesome adjustment.

It is a block diagram which shows the structure of the ship propulsion system which concerns on embodiment of this invention. It is a figure which compares the transient response characteristic at the time of issuing a gear shift command in a ship propulsion system, and the transient response characteristic of the conventional anti-wide-up PID control.

Hereinafter, embodiments for carrying out the present invention will be described in detail.
FIG. 1 is a block diagram showing a configuration of a ship propulsion system 1 (rotary drive system) according to an embodiment of the present invention.

  The ship propulsion system 1 uses the anti-windup type PID control so that the fuel G supplied from the governor 15 to the main engine 14 so that the rotation speed of the screw 11 (control target) that gives propulsion power to the ship becomes the target rotation speed. The injection amount of the is controlled.

  The ship propulsion system 1 includes a screw 11, a main shaft 12 to which the screw 11 is attached (a control target), a speed reducer 13 (rotation drive means) that transmits input rotation to the main shaft 12 at a predetermined reduction ratio, and a supply amount of fuel G A main engine (engine) 14 (rotation drive means) 14 that obtains the corresponding rotation and inputs it to the speed reducer 13, and a governor 15 that adjusts the injection amount of fuel G supplied to the main engine 14 according to the governor opening command value (rotation drive) Means).

  Further, the ship propulsion system 1 includes a sensor 20 (detection means) that outputs a signal corresponding to the rotational speed of the main shaft 12, a throttle operation unit 30 that outputs a rotational speed command value Fs (t) corresponding to the throttle operation amount, and a sensor. A spindle rotation control device 40 (rotation speed control device) that outputs a governor opening command value based on the signal (rotation speed) output from 20 and the rotation speed command value Fs (t) output from the throttle operation unit 30. I have.

  The spindle rotation control device 40 includes an adder 41 (calculation means), a differential constant multiplier 42 (differential correction amount calculation means), a differentiator 43 (differential correction amount calculation means), and a proportional constant multiplier 44 (proportional correction amount calculation means). ).

The adder 41 performs an addition operation using the rotation speed command value Fs (t) output from the throttle operation unit 30 as a positive input signal and the rotation speed output from the sensor 20 as a negative input signal. The rotation speed deviation Δrpm is output.
The differential constant multiplier 42 multiplies the rotational speed deviation Δrpm output from the adder 41 by the differential constant Kd.
The differentiator 43 differentiates the multiplication result output from the differential constant multiplier 42 and outputs a differential correction amount Fd (t), which is the calculation result, to the adder 53.
The proportional constant multiplier 44 multiplies the rotational speed deviation Δrpm output from the adder 41 by a differential constant Kp.

  Further, the spindle rotation control device 40 includes an integral limiter function calculator 45, an integral limiter expansion calculation unit 46 (limit value expansion means), an integral constant multiplier 47, an adder 48, an integrator 49 (integration correction amount calculation means), An adder 50, a multiplier 51, a limiter circuit 52 (differential correction amount limiting means), and an adder 53 (addition means) are provided.

  The integral limiter function calculator 45 uses the rotation speed command value Fs (t) output from the throttle operation unit 30 to calculate the integral limiter function Fl [Fs (t)] as follows.

Fl [Fs (t)] = c × [Fs (t)] ³ c is a conversion factor

The function Fl (s) is the upper limit value (absolute value of the lower limit value) of the integral term that is initially set, and functions to suppress overshoot and undershoot. The controlled object has a characteristic that the governor opening degree is the third power with respect to the rotational speed command value Fs (t). For this reason, the function Fl (s) has a third power term of Fs (t). However, if the control target is different, the function Fl (t) may have nonlinear characteristics.
Then, the integral limiter function calculator 45 outputs the calculation result to the integral limiter enlargement calculation unit 46.

  The integration limiter enlargement calculation unit 46 includes an integration saturation detection unit 46a, an integration limiter addition function calculation unit 46b, a zero value output unit 46c, a selection unit 46d, and an adder 46e.

  The integral saturation detection unit 46a determines whether the following equation (1) is satisfied using the rotation speed deviation Δrpm output from the adder 41.

      | Δrpm |> 0.5rpm (1)

  When the formula (1) is satisfied, the rotation speed is not near the target value (rotation speed command value). However, when the expression (1) is not satisfied, the rotation speed is near the target value (error is 0.5 rpm). Below).

  Further, the integral saturation detection unit 46a determines whether the following equation (2) is satisfied by using ΔFi (t) that is the calculation result of the adder 50.

      ΔFi (t) <0 (2)

  When Expression (2) is satisfied, the integral term (output of the integrator 49) of the PID controller is saturated and exceeds the upper limit limiter or the lower limit limiter.

  When both of the expressions (1) and (2) are established, the integral saturation detection unit 46a outputs an ON signal that instructs to enlarge the upper limit value (absolute value of the lower limit value) of the integral term to the selection unit 46d. . Further, the integration limiter enlargement calculation unit 46 outputs an off signal instructing to stop the enlargement of the upper limit value (absolute value of the lower limit value) of the integral term when at least one of the expressions (1) and (2) is not satisfied. The data is output to the selection unit 46d.

  The integration limiter addition function calculator 46b uses the proportional correction amount Fp (t) output from the proportional constant multiplier 44 to calculate the integration limiter addition function Fl2 [Fp (t)] as follows.

      Fl2 [Fp (t)] = n × Fp (t)

The integral limiter addition function Fl2 [Fp (t)] is a proportional term that multiplies the proportional correction amount Fp (t) by n, and corresponds to the expansion range of the upper limit value of the integral term. For this reason, as the rotational speed approaches the target value (rotational speed command value), the integral limiter addition function Fl2 [Fp (t)] decreases, and the expansion range of the upper limit value also decreases.
When the rotation speed is close to the target value (substantially matches the target value), the influence (correction width) that the integral limiter addition function Fl2 [Fp (t)] has on the upper limit value is minimized. At this time, the integral limiter function Fl (t) is in a state corresponding to the entire upper limit value, and the upper limit value expansion stops at this point.
The zero value output unit 46c outputs a zero value for setting the expansion width of the upper limit value of the integral term to zero.

  When the ON signal is input from the integration saturation detection unit 46a, the selection unit 46d selects the integration limiter addition function Fl2 [Fp (t)] calculated by the integration limiter addition function calculator 46b, and the integration saturation detection unit When an off signal is input from 46a, the zero value output from the zero value output unit 46c is selected, and the selected value is output to the adder 46e.

The adder 46e includes an integral limiter function Fl [Fs (t)] (an upper limit value of the integral term) input from the integral limiter function calculator 45, and a value (an expanded width of the upper limit value) input from the selection unit 46d. And the calculation result is output to the multiplier 51 and the limiter circuit 52.
The value output by the adder 46e indicates the upper limit value (absolute value of the lower limit value) finally adjusted for the integral term.

  The multiplier 51 outputs the lower limit value finally adjusted for the integral term by multiplying the calculation result of the adder 46e by (−1).

When the integral term output from the integrator 49 is within the range from the lower limit value to the upper limit value, the limiter circuit 52 outputs the integral term as it is to the adder 53 as the integral correction amount Fi (t).
On the other hand, when the integral term is smaller than the lower limit value, the limiter circuit 52 outputs the lower limit value to the adder 53 as the integral correction amount Fi (t).

  Further, when the integral term is larger than the upper limit value, the limiter circuit 52 outputs the upper limit value to the adder 53 as the integral correction amount Fi (t). That is, when the integral term is not saturated, the limiter circuit 52 outputs the integral term as the integral correction amount Fi (t) as it is, and when the integral term is saturated exceeding the upper limit value or the lower limit value, The upper limit value or the lower limit value is output as the integral correction amount Fi (t).

  The adder 53 includes a differential correction amount Fd (t) output from the differentiator 43, a proportional correction amount Fp (t) output from the proportional constant multiplier 44, and an integral correction amount Fi (t) output from the limiter circuit 52. ) Is added to calculate the governor opening degree command.

  The governor 15 controls the injection amount of the fuel G to the main engine 14 according to the governor opening degree command calculated by the adder 53. As a result, the main engine 14 rotates the screw 11 through the speed reducer 13 and the main shaft 12 so as to reach the target rotational speed.

  In the ship propulsion system 1, when a transitional change is given to the control target, for example, when the ship starts from a stopped state, the spindle rotation control device 40 performs the following arithmetic processing.

  When the ship starts from a stopped state, first, the rotation speed input to the spindle rotation control device 40 is zero. The adder 41 in the spindle rotation control device 40 outputs the rotation speed command value Fs (t) as it is as the rotation speed deviation Δrpm. That is, the absolute value of the rotational speed deviation Δrpm is a very large value compared to 0.5 rpm.

  For this reason, the output value (integral term) of the integrator 49 suddenly increases and becomes saturated, so ΔFi (t) that is the output value of the adder 50 becomes less than zero. Therefore, the integral saturation detection unit 46a outputs the ON signal to the selection unit 46d because both the above-described equations (1) and (2) are established. The selection unit 46d selects the integral limiter addition function Fl2 [Fp (t)] and outputs it to the adder 46e.

  The adder 46e adds the integral limiter addition function Fl2 [Fp (t)] corresponding to the enlargement width to the integral limiter function Fl [Fs (t)] corresponding to the absolute values of the upper limit value and the lower limit value. The upper limit value and the lower limit value of the limiter circuit 52 are expanded.

  The integral limiter addition function Fl2 [Fp (t)] corresponding to the period of the transient response, the expansion range of the upper limit value and the lower limit value increases in accordance with the proportional term (output of the proportional constant multiplier 44). For this reason, the output value of the integrator 49 corresponding to the integral term increases rapidly but is input to the adder 53 without being saturated. As a result, the rotational speed of the screw 11 rapidly approaches the target value, and the transient response period is shortened.

  On the other hand, as the rotation speed of the screw 11 approaches the target value, the rotation speed deviation Δrpm decreases, so the output value of the proportional constant multiplier 44 corresponding to the proportional term also decreases, and the upper and lower limit values are expanded. Get smaller.

  When the rotational speed of the screw 11 reaches the vicinity of the target value, the rotational speed deviation Δrpm becomes very small and the above-described formula (1) is not established, and the selection unit 46d outputs the zero value output from the zero value output unit 46c. Select. At this time, the expansion range of the upper limit value and the lower limit value becomes zero, and the calculation result of the integral limiter function calculator 45 is set as the limiter value (upper limit value and lower limit value) in the limiter circuit 52 as it is. Thereby, since the anti-windup method by the initially set upper limit value and lower limit value works on the integral term, the windup phenomenon of the rotation speed of the screw 11 as the control target can be suppressed.

  FIG. 2 shows the transient response characteristics of the rotational speed and the control amount (enlarged width) when the shift command is issued in the ship propulsion system 1, and the transient response characteristics of the rotational speed and control amount of the conventional anti-wide-up PID control. It is a figure to compare.

  Both the rising speed of the controlled variable and the response speed (transient period) of the rotational speed in the ship propulsion system 1 are both shortened compared to the conventional case. In the static state, the number of revolutions and the control amount of the marine vessel propulsion system 1 have less overshoot than conventional.

  As described above, the ship propulsion system 1 is the output of the integrator 49 when a transitional change is given to the control target (for example, when a large target rotational speed is set for the main shaft 12 in the rotation stopped state). The integral term is saturated. At this time, the ship propulsion system 1 temporarily expands the upper limit value and the lower limit value, so that the integral term at the time of the transient response does not saturate, and the transient response time of the controlled object can be shortened.

Further, the ship propulsion system 1 decreases the integral limiter addition function Fl2 (s) corresponding to the expansion range of the upper limit value and the lower limit value as the rotational speed of the main shaft 12 approaches the target value, and further rotates the main shaft 12. When the number reaches the vicinity of the target value, the enlarged upper limit value and lower limit value are returned to the initial initial values.
As a result, in the marine vessel propulsion system 1, the anti-windup method works, and it is possible to suppress the windup phenomenon of the rotational speed of the main shaft 12 and increase the total gain.

  The present invention is not limited to the above-described embodiments, and can be applied to the following modifications.

For example, the present invention is not limited to the ship propulsion system 1 and can be applied as long as it controls the number of rotations to be controlled.
The drive means to be controlled is not limited to the main engine (engine) 14 as in the above-described embodiment, but may be a motor or other prime mover.

The integral limiter function calculator 45 is not limited to the case of calculating Fl [Fs (t)] = n × [Fs (t)] ³ . Different functions may be calculated according to the control target.
The integral limiter addition function calculator 46b is not limited to the case of calculating Fl2 [Fp (t)] = n × Fp (t). Another function may be calculated as long as it is an increasing function of Fp (t).

  DESCRIPTION OF SYMBOLS 1 Ship propulsion system (rotation drive system), 11 Screw (control object), 12 Spindle (control object), 13 Reducer (rotation drive means), 14 Main engine (rotation drive means), 15 Governor (rotation drive means), 20 sensors (detection means), 30 throttle operation section, 40 spindle rotation control device (rotation speed control device), 41 adder (calculation means), 42 differential constant multiplier (differential correction amount calculation means), 43 differentiator (differentiation) Correction amount calculation means), 44 proportional constant multiplier (proportional correction amount calculation means), 46 integral limiter expansion calculation section (limit value expansion means), 49 integrator (integration correction amount calculation means), 52 limiter circuit (integration correction amount) Limiting means), 53 adder (adding means)

Claims (5)

A calculation means for calculating a rotation speed deviation which is a deviation between the target rotation speed of the control object and the actual rotation speed of the control object;
Differential correction amount calculation means for calculating a differential correction amount based on the rotational speed deviation calculated by the calculation means;
Proportional correction amount calculating means for calculating a proportional correction amount based on the rotational speed deviation calculated by the calculating means;
An integral correction amount calculating means for calculating an integral correction amount based on the rotational speed deviation calculated by the calculating means;
When the integral correction amount calculated by the integral correction amount calculation means exceeds the upper limit value, the integral correction amount is limited to the upper limit value and output, and when the integral correction amount falls below the lower limit value, the integral correction amount An integral correction amount limiting means for outputting the integral correction amount as it is when the integral correction amount is not less than the lower limit value and not more than the upper limit value.
When the absolute value of the rotational speed deviation exceeds a predetermined value and the integral correction amount is limited by the integral correction amount limiting means, according to the proportional correction amount calculated by the proportional correction amount calculating means, Limit value expanding means for expanding the upper limit value and the lower limit value of the integral correction amount limiting means;
The differential correction amount calculated by the differential correction amount calculating means, the proportional correction amount calculated by the proportional correction amount calculating means, and the integral correction amount output from the integral correction amount limiting means are added, and the control object Adding means for outputting a control signal for controlling the rotational speed ,
The limit value expanding means expands the upper limit value by adding an expansion width that increases with an increase in the proportional correction amount to the upper limit value, and subtracts the expansion width from the lower limit value. A rotation speed control device characterized by enlarging the value . The limit value expanding means sets the upper limit value and the lower limit value when the absolute value of the rotational speed deviation is equal to or less than a predetermined value or when the integral correction amount is not limited by the integral correction amount limiting means. The rotation speed control device according to claim 1, wherein the rotation speed control device is set to an initial value before enlargement . The rotational speed control device according to claim 1 , wherein the control target is a rotary shaft that rotates a propulsion device of a ship . Calculating a rotational speed deviation which is a deviation between the target rotational speed of the controlled object and the actual rotational speed of the controlled object;
Based on the calculated rotational speed deviation, a differential correction amount, a proportional correction amount, and an integral correction amount are calculated,
When the absolute value of the rotational speed deviation exceeds a predetermined value and the integral correction amount is saturated, the upper limit value and the lower limit value of the integral correction amount are expanded according to the calculated proportional correction amount,
When the calculated integral correction amount exceeds the enlarged upper limit value, the integral correction amount is limited to the upper limit value and output, and when the integral correction amount falls below the enlarged lower limit value, the integral correction amount Is limited to the lower limit value, and when the integral correction amount is not less than the enlarged lower limit value and not more than the enlarged upper limit value, the integral correction amount is output as it is,
Adding the calculated differential correction amount, the calculated proportional correction amount, and the output integral correction amount to output a control signal for controlling the rotation speed of the control target;
In enlarging the upper limit value and the lower limit value, the upper limit value is expanded by adding to the upper limit value an enlargement range that increases as the proportional correction amount increases, and the enlargement range is subtracted from the lower limit value. The rotation speed control method is characterized by enlarging the lower limit value. The rotation speed control device according to any one of claims 1 to 3,
Detecting means for detecting the actual rotational speed of the controlled object used in the rotational speed control device;
Rotation drive means for rotating the control object based on a control signal output from the rotation speed control device;
A rotational drive system comprising:

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