JP6988667B2 - Controllers, adjustment methods, and adjustment systems - Google Patents

Description

The present disclosure relates to a technique for adjusting an electric valve to bring a controlled amount closer to a target value.

There is a technique for adjusting a controlled variable (for example, temperature, etc.) in a controlled object by outputting a command signal related to an operation amount based on a target value and driving a motor based on the command signal. For example, in Japanese Patent Application Laid-Open No. 9-198147 (Patent Document 1), the temperature of the controlled object space is detected by a thermocouple arranged in the controlled object space, and the controlled object space is determined based on the deviation from the set temperature. A technique for performing a temperature control process for maintaining a set temperature is disclosed.

Japanese Unexamined Patent Publication No. 9-198147

By the way, when the flow rate of a fluid such as liquid or gas is adjusted to bring the temperature of the controlled object closer to the target value, control is performed using an electric valve, but the electric valve has mechanical friction and the inside of the pipe. The rate of change in valve opening may decrease due to the presence of foreign matter. In such a case, it may be difficult to make adjustments closer to the target value only by making adjustments based on the controlled amount of the controlled object without taking into consideration the state of the electric valve.

The present disclosure has been made to solve the above-mentioned problems, and an object in a certain aspect is to provide a technique for determining the current state of an electric valve when controlling a target value. Is.

In one example of the present disclosure, a regulator that controls a controlled object by using an electric valve that receives a first command signal and operates in the open direction and also receives a second command signal and operates in the closed direction as an operating element. Therefore, a command signal that intermittently outputs either the first command signal or the second command signal so that the control amount acquired from the control target matches a preset target value. The output unit, the holding unit that holds the reference change pattern of the valve opening of the electric valve acquired by prior calibration, the command signal output from the command signal output unit, and the valve opening of the electric valve. A state estimation unit that estimates the state of the electric valve based on the feedback signal indicating the degree of the above is provided, and the state estimation unit can be used as a single command signal intermittently output from the command signal output unit. The change amount calculation unit that calculates the change amount of the valve opening of the electric valve according to the response, and the length of time that the output of the command signal for one time is continued are acquired, and the length of time that the output is continued is long. From this, the effective time calculation unit that calculates the effective time, which is the time when the electric valve is substantially operated by reducing the predetermined dead time, the amount of change in the valve opening of the electric valve, and the reference. The electric valve is calculated based on the change amount corresponding to the command signal for one change of the change pattern and the effective time, and is based on the degree of deviation per time based on the change amount of the reference change pattern. Includes a determination unit that determines whether or not is in a predetermined abnormal state.

According to this disclosure, the regulator can determine the current state of the motorized valve when controlling for a target value.

In one example of the present disclosure, the effective time calculation unit is used to calculate the effective time among the plurality of waste times according to the current position of the electric valve at the time when the command signal for one time is output. Select a time.

According to this disclosure, if the current position of the motorized valve at the time when the output of the command signal is started is the fully closed or fully open position, the regulator can appropriately select the dead time according to the position.

In one example of the present disclosure, the plurality of wasted times are the wasted time when the position of the electric valve changes from the fully closed position and the opening changes from the position where the electric valve is fully open. Including wasted time.

According to this disclosure, the regulator can select the information required to calculate the effective time when the position of the motorized valve is in the fully closed or fully open position.

In one example of the present disclosure, the effective time calculation unit determines the current position of the electric valve at the time when the command signal for one time is output and the current change direction of the electric valve indicated by the command signal for one time. The waste time used for calculating the effective time is selected from the plurality of waste times according to the change direction immediately before the electric valve indicated by the command signal for one time.

According to this disclosure, the regulator can select an appropriate dead time according to the direction of change when the motorized valve is located in the middle from fully closed to fully open.

In one example of the present disclosure, the plurality of waste times are the waste time when the position of the electric valve changes in the same direction as the immediately preceding change direction at a position in the middle of fully closed to fully open, and the position of the electric valve. It includes the wasted time when the position in the middle of the above changes in a direction different from the immediately preceding change direction.

According to this disclosure, the regulator can select the information required to calculate the effective time when the position of the motorized valve is in the middle of fully closed to fully open.

In one example of the present disclosure, the change amount calculation unit is based on the current position of the electric valve at the time when the command signal for one time is output and the length of time for the output of the command signal for one time to continue. Then, the section of the amount of change of the reference change pattern corresponding to the one command signal is specified.

According to this disclosure, the regulator can identify the optimum amount of change in the reference opening for determining the performance of the current motorized valve.

In one example of the present disclosure, the change amount calculation unit approximates a plurality of linear lines having linearity when the valve opening change pattern is a curve having non-linearity.

According to this disclosure, the regulator can easily calculate the amount of change in the resistance value with respect to the amount of change in the opening degree of the electric valve.

An example of the present disclosure further includes an alarm signal output unit that outputs an alarm signal when the determination unit determines that the abnormal state is present.

According to this disclosure, the regulator can reliably notify the user that the motorized valve is in an abnormal state.

In one example of the present disclosure, a regulator that controls a controlled object by using an electric valve that receives a first command signal and operates in the open direction and also receives a second command signal and operates in the closed direction as an operating element. The first command signal and the second command signal are intermittently output so that the control amount acquired from the control target matches the preset target value. Steps to be performed, a step to hold a reference change pattern of the valve opening of the electric valve acquired by prior calibration, a command signal output by the step to be intermittently output, and a valve of the electric valve. A step of estimating the state of the electric valve based on the feedback signal indicating the degree of opening is provided, and the step of estimating the state is one time output intermittently by the step of intermittently outputting. The step of calculating the amount of change in the valve opening degree of the electric valve according to the command signal of 1 and the length of time during which the output of the command signal for one time is continued are acquired, and the time during which the output is continued is obtained. The step of calculating the effective time, which is the time when the electric valve is substantially operated by subtracting the predetermined dead time from the length, the amount of change in the valve opening of the electric valve, and the reference change pattern. Based on the degree of deviation per time based on the amount of change in the reference change pattern, which is calculated based on the amount of change corresponding to the command signal for one time and the effective time, the electric valve is preliminarily used. Includes a step to determine if it is a defined abnormal condition.

According to this disclosure, the regulator can determine the state of the motorized valve when it controls the target value.

In one example of the present disclosure, an electric valve that receives a first command signal and operates in the open direction and that receives a second command signal and operates in the closed direction, and the electric valve are used as operating elements for control. A controller that controls an object, and intermittently either the first command signal or the second command signal so that the control amount acquired from the controlled object matches a preset target value. A command signal output unit that outputs a command signal, a holding unit that holds a reference change pattern of the valve opening of the electric valve acquired by prior calibration, a command signal output from the command signal output unit, and the above. A state estimation unit that estimates the state of the electric valve based on a feedback signal indicating the degree of valve opening of the electric valve is provided, and the state estimation unit is intermittently output from the command signal output unit. The change amount calculation unit that calculates the change amount of the valve opening of the electric valve according to the command signal for one time, and the length of time that the output of the command signal for one time is continued are acquired, and the output is also concerned. By subtracting a predetermined dead time from the length of continuous time, the effective time calculation unit that calculates the effective time, which is the time when the electric valve is substantially operated, and the valve opening of the electric valve The degree of deviation per hour based on the amount of change in the reference change pattern, which is calculated based on the amount of change, the amount of change corresponding to the command signal for one time of the reference change pattern, and the effective time. Based on this, the present invention includes a regulator provided with a determination unit for determining whether or not the electric valve is in a predetermined abnormal state.

According to this disclosure, the regulator can determine the state of the motorized valve when it controls the target value.

In a certain aspect, the state of the electric valve can be determined when the target value is controlled.

It is a figure which shows the configuration example of the adjustment system 1 according to this embodiment. It is a figure explaining the function of the state estimation unit 22 according to this embodiment. It is a figure which shows the relationship between the change amount P1 of the measurement opening degree, the change amount P2 of a reference opening degree, and the follow-up degree P3 according to this embodiment. It is a figure explaining the derivation of the reference change pattern BP according to this embodiment. It is a figure explaining the waste time TD1 when the opening degree changes from the fully closed position to the opening direction of the electric valve 32 according to this embodiment. It is a figure explaining the waste time TD2 when the opening degree changes from the fully open position to the closing direction of the electric valve 32 according to this embodiment. It is a figure explaining the change amount P2 of the reference opening degree and the resistance value change amount according to this embodiment. It is a figure explaining the specific example of the abnormality determination processing according to this embodiment. It is a block diagram which shows the hardware configuration example of the adjustment system 1 according to this embodiment. It is a flowchart which shows a part of the process executed by the processor 20 according to this embodiment. It is a flowchart which shows a part of the process about the setting of the waste time TD executed by the processor 20 according to this embodiment. It is a figure explaining the calculation process of the effective time TE of the processor 20 according to this embodiment.

Hereinafter, embodiments according to the present invention will be described with reference to the drawings. In the following description, the same parts and components are designated by the same reference numerals. Their names and functions are the same. Therefore, the detailed description of these will not be repeated.

<A. Application example>
<A-1. System configuration>
An application example of the present invention will be described with reference to FIG. FIG. 1 is a diagram showing a configuration example of the adjustment system 1 according to the present embodiment. The regulation system 1 is a system that regulates the temperature in a controlled object 4 such as a furnace, and includes a regulator 2 and a control valve 3.

The regulator 2 detects the temperature of the controlled object 4 and issues a command to the control valve 3. Therefore, the control valve 3 becomes an operating element of the controller 2. The regulator 2 includes a command signal output unit 21, a state estimation unit 22, and a storage device 23.

The command signal output unit 21 receives the target value SV input from the external terminal (not shown) operated by the user and the control amount PV from the control target 4, and brings the control amount PV closer to the target value SV. A command signal MV indicating the amount is output. The command signal output unit 21 outputs the command signal MV to the control valve 3 and the state estimation unit 22.

The target value SV is the desired temperature in the controlled object 4 of the furnace or the like, and the controlled variable PV is the actual temperature in the furnace. Further, the command signal MV is a signal instructing the control of the control valve 3 in order to reduce the difference between the desired temperature in the furnace and the actual temperature.

The control valve 3 adjusts the flow rate of the fluid supplied to the controlled object 4 based on the command signal MV from the regulator 2. The control valve 3 has a motor 31, an electric valve 32, a pipe 33, and a potentiometer 34. The motor 31 rotates in a certain direction (for example, forward rotation) based on the first command signal included in the command signal MV. Further, the motor 31 rotates (for example, reverses) in a direction opposite to a certain direction based on the second command signal included in the command signal MV. The first command signal and the second command signal are signals that are intermittently output from the command signal output unit 21. The command signal output unit 21 does not output the other signal while the command signal output unit 21 is outputting one of the signals.

The motor 31 continuously performs forward rotation or reverse rotation operation according to the continuous time of one command signal MV output from the command signal output unit 21. The electric valve 32 moves in either the open direction or the closed direction due to the rotation of the motor 31, and the opening degree changes. Specifically, the position of the electric valve 32 changes in the opening direction due to the forward rotation of the motor based on the first command signal. When the electric valve 32 operates in the opening direction, the flow rate of the fluid (for example, gas) flowing into the controlled object 4 through the pipe 33 increases. Further, the position of the electric valve 32 changes in the closing direction due to the reversal of the motor based on the second command signal. By operating the electric valve 32 in the closing direction, the flow rate of the gas flowing into the controlled object 4 through the pipe 33 is reduced.

By changing the opening degree of the electric valve 32, the flow rate of gas in the pipe 33 also changes, and the thermal power of the burner (burner 35 shown in FIG. 9 described later) provided at one end of the pipe 33 on the control target 4 side is adjusted. Will be done. Specifically, when the thermal power of the burner is increased, the temperature in the controlled object 4 is increased, and when the thermal power of the burner is decreased, the temperature in the controlled object 4 is decreased. The controlled variable PV indicating the temperature adjusted in this way is output from the controlled object 4 to the command signal output unit 21.

Further, the voltage input from the potentiometer 34 to the state estimation unit 22 of the regulator 2 changes due to the rotation of the motor 31. The potentiometer 34 is a device that converts the amount of movement and the angle of rotation associated with the rotation of the motor 31 into a voltage, and specifically, is a variable resistor, a rotary encoder, or the like. In this embodiment, a variable resistor will be described as an example, but other devices may be used as long as they are devices that convert the angle of rotation and the amount of movement as described above.

The potentiometer 34 outputs a feedback signal FB corresponding to the amount of movement of the electric valve 32 generated by the rotation of the motor 31 to the state estimation unit 22. In other words, the potentiometer 34 outputs a feedback signal FB according to the amount of change in the valve opening degree of the electric valve 32 whose opening degree changes as the motor 31 rotates to the state estimation unit 22.

In the electric valve 32, for example, the fully closed position has an opening degree of 0%, and the fully open position has an opening degree of 100%. The amount of change in the opening degree of the electric valve 32 is the rate of change in the opening degree (rate of change). For example, when the position of the electric valve 32 changes from the fully closed position to the fully open position, the amount of change in the opening degree of the electric valve 32 becomes + 100%. Further, for example, when the position of the electric valve 32 changes by 20% in the opening direction from the fully closed position (opening 0% → 20%), the amount of change in the opening of the electric valve 32 becomes + 20%. Further, when the position of the electric valve 32 is half the position from the fully closed position to the fully open position (opening 50%) and the change is 30% in the closing direction (opening 50% → 20%), the electric valve The amount of change in the opening degree of 32 is -30%.

<A-2. Function of state estimation unit (change amount calculation unit)>
The state estimation unit 22 estimates the state of the electric valve 32 based on the command signal MV output from the command signal output unit 21 and the feedback signal FB output from the potentiometer 34. Specifically, the state estimation unit 22 estimates the state of the electric valve 32 based on the length of time that the output of the command signal MV continues and the degree of the valve opening degree of the electric valve 32.

The function of the state estimation unit 22 will be described with reference to FIG. FIG. 2 is a diagram illustrating the function of the state estimation unit 22 according to the present embodiment. The state estimation unit 22 includes a change amount calculation unit 221, an effective time calculation unit 223, and a determination unit 225.

The change amount calculation unit 221 calculates the follow-up degree P3 based on the reference change pattern of the valve opening degree of the electric valve 32 according to the command signal MV for one time intermittently output from the command signal output unit 21. .. The follow-up degree P3 is a reference change pattern of the valve opening degree (for example, a reference change pattern of the valve opening degree shown in FIG. 7 or the like described later, which is acquired at the time of calibration of the electric valve 32, and is also referred to as a reference change pattern hereafter. ) It is a value indicating how much the change amount of the current electric valve 32 and the change amount of the current electric valve 32 can be compared with the change amount of the (ideal) electric valve 32 at the normal time shown in BP, and the performance of the current electric valve 32. It is an index showing. The change amount calculation unit 221 calculates the follow-up degree P3 by dividing the change amount P1 of the measurement opening degree by the change amount P2 of the reference opening degree.

The change amount P1 of the measurement opening degree is a value calculated by the command signal MV for one time when the adjustment system 1 is actually operated after being manufactured. At the timing when one command signal MV output from the command signal output unit 21 is generated (ON), the motor 31 starts forward rotation or reverse rotation, and the opening degree of the electric valve 32 changes. While the output of this command signal MV continues, the rotation of the motor 31 and the change in the opening degree of the electric valve 32 continue. When the output of the command signal MV ends (OFF), the motor 31 stops rotating, and the change in the opening degree of the electric valve 32 becomes zero.

Further, the voltage of the feedback signal FB changes as the resistance value of the variable resistor of the potentiometer 34 changes with the rotation of the motor 31. For example, the voltage of the feedback signal FB decreases as the resistance value of the variable resistor decreases with the forward rotation of the motor 31. Further, for example, the voltage of the feedback signal FB increases as the resistance value of the variable resistor increases with the inversion of the motor 31.

In this way, the change amount calculation unit 221 provides feedback according to the amount of change in voltage due to the change in the resistance value of the variable resistor of the potentiometer 34 when the adjustment system 1 is actually operated after being manufactured. The signal FB is acquired, and the change amount P1 of the measurement opening degree of the electric valve 32 is calculated. The change amount calculation unit 221 stores the position (current position) at which the change in the opening degree of the electric valve 32 in the change amount P1 of the measurement opening degree starts, as the initial position of the electric valve 32 stored in the storage device 23. And the amount of change in the opening degree of the electric valve 32 so far (before the previous time).

The change amount P2 of the reference opening degree is the change amount in the section corresponding to the command signal MV for one time in the reference change pattern BP. Specifically, the change amount P2 of the reference opening is 20% (opening 60%) corresponding to the change amount of the resistance values Q1 to Q2 in the section of time t17 to t18 (time T1) of FIG. 7, which will be described later. → 80%). The change amount calculation unit 221 specifies a section of the change amount P2 of the reference opening corresponding to the change amount P1 of the measurement opening degree, and calculates the follow-up degree P3.

The change amount calculation unit 221 changes the measurement opening degree from the current position of the electric valve 32 at the time when one command signal MV is output and the length of time that the output of this one command signal MV is continued. Specify the interval of the amount of change corresponding to the amount P1. Thereby, the regulator 2 can specify the optimum change amount P2 of the reference opening degree for determining the performance of the current electric valve 32. The change amount calculation unit 221 is, for example, when the current position of the electric valve 32 at the time when the command signal MV for one time in the change amount P1 of the measurement opening is output is 60%, and the command signal for this one time is When the output of the MV is the same as the length of time (time T1) from time t17 to t18, the reference change amount in the section of time t17 to t18 in the reference change pattern BP is used. Identify. As for the reference change amount in the section from time t17 to t18, the change amount of the opening corresponding to the change amount r7 of the resistance value is 20%, and this change amount corresponds to the change of the reference opening corresponding to the current measurement opening P1. The amount is P2.

The relationship between the change amount P1 of the measurement opening degree, the change amount P2 of the reference opening degree, and the follow-up degree P3 will be described with reference to FIG. FIG. 3 is a diagram showing the relationship between the change amount P1 of the measurement opening degree, the change amount P2 of the reference opening degree, and the follow-up degree P3 according to the present embodiment. The horizontal axis of FIG. 3 indicates the value of the amount of change (rate of change).

For example, when the change amount in the section from time t17 to t18 is applied and the change amount P2 of the reference opening is 20%, when the change amount P1 of the measurement opening is 14%, the follow-up degree P3 is 70. It becomes%. That is, the current performance of the electric valve 32 is 70% as compared with the normal state (100%). In other words, the amount of deterioration of the current electric valve is 30%, and the degree of deviation based on the amount of change in the reference change pattern BP is 30%. As described above, the degree of dissociation is an index showing the current degree of deterioration of the electric valve 32 with respect to the normal state, and the degree of follow-up and the degree of dissociation have a contradictory relationship.

A specific calculation method of the reference change pattern BP will be described with reference to FIG. FIG. 4 is a diagram illustrating the derivation of the reference change pattern BP according to the present embodiment. The horizontal axis of FIG. 4 shows the time (seconds), and on each time axis, the ON / OFF state of the first command signal, the ON / OFF state of the second command signal, and the amount of change in the opening degree are shown from the top. ..

At time t10, the command signal output unit 21 outputs the first command signal to the control valve 3 (first command signal ON), so that the motor 31 starts to rotate forward. Due to the forward rotation of the motor 31, the electric valve 32 changes from the fully closed position to the open direction, and the opening degree changes. The change amount calculation unit 221 measures the change amount of the opening degree of the electric valve 32 from the timing when the first command signal is turned on (time t10) to the timing when the first command signal is turned off (time t20). It is calculated from the amount of change in voltage based on the change in resistance value of 34.

Specifically, in the change amount calculation unit 221, the electric valve 32 in the fully closed position starts changing in the opening direction from the timing (time t10) when the first command signal is turned ON, and the first command is given. A feedback signal FB indicating a change in voltage until the signal changes to the fully open position by the timing when the signal is turned off (time t20) is acquired. Based on the acquired feedback signal FB, the change amount calculation unit 221 indicates a reference change pattern BP1 indicating a change in the resistance value from the fully closed position to the fully open position of the electric valve 32 and a change in the opening degree. Is derived and held in the storage device 23.

Since the first command signal and the second command signal are not output during the time t20 to t30, the position of the electric valve 32 remains in the fully open position, and the opening degree does not change.

At time t30, the command signal output unit 21 outputs the second command signal to the control valve 3 (second command signal ON), so that the motor 31 starts reversing. Due to the reversal of the motor 31, the electric valve 32 changes from the fully open position to the closing direction, and the opening degree changes. The change amount calculation unit 221 measures the change amount of the opening degree of the electric valve 32 from the timing when the second command signal is turned on (time t30) to the timing when the second command signal is turned off (time t40). It is calculated from the amount of change in voltage based on the change in resistance value of.

Specifically, in the change amount calculation unit 221, the electric valve 32 at the fully open position starts changing in the closing direction from the timing (time t30) when the second command signal is turned ON, and the second command signal is displayed. Acquires a feedback signal FB indicating a change in voltage until the voltage changes to the fully closed position by the timing (time t40) when is turned off. Based on the acquired feedback signal FB, the change amount calculation unit 221 indicates a reference change pattern BP2 indicating a change in resistance value from a fully open position to a fully closed position and a change in opening degree of the electric valve 32. Is derived and held in the storage device 23.

The value of the opening degree for each time of the above-mentioned reference change pattern BP1 from fully closed to fully opened and the reference change pattern BP2 from fully opened to fully closed is different. Such different values are due to the difference in torque between the forward rotation and the reverse rotation of the motor 31, the difference in speed when the electric valve 32 moves in the open direction and when it moves in the closed direction, and the like. be.

In this way, the change amount calculation unit 221 derives the reference change pattern BP1 based on the command signal MV by the command signal output unit 21. The command signal output unit 21 generates (ON) one command signal MV when the position of the electric valve 32 is fully closed, and continues to output the command signal MV while changing in the open direction. Then, when the position is fully opened, the output of the command signal MV is terminated (OFF). Further, the change amount calculation unit 221 derives the reference change pattern BP2 based on the command signal MV by the command signal output unit 21. The command signal output unit 21 generates (ON) one command signal MV when the position of the electric valve 32 is fully open, and continues to output the command signal MV while changing in the closing direction. Then, when the fully closed position is reached, the output of the command signal MV is terminated (OFF). In the following, the reference change pattern BP1 and BP2 may be collectively referred to as the reference change pattern BP.

As described above, the reference change pattern BP is derived at the time of initial operation of the adjustment system 1 or at the time of calibration such as maintenance of the adjustment system 1. That is, it is performed when the electric valve 32 is in a normal state. Therefore, the change amount P2 of the reference opening degree in the reference change pattern BP is the change amount in the normal state of the electric valve 32. The reference change pattern BP is held in the storage device 23. When a new reference change pattern BP is calculated after the reference change pattern BP is stored in the storage device 23, the updated reference change pattern BP is held in the storage device 23. The storage device 23 is composed of, for example, a non-volatile storage device such as a flash memory.

<A-3. Function of state estimation unit (effective time calculation unit)>
Returning to FIG. 2, the effective time calculation unit 223 of the state estimation unit 22 calculates the effective time TE by subtracting the waste time TD from the time when the output of the command signal MV is continued. The effective time TE is the time during which the electric valve 32 is substantially operated. First, the dead time TD will be described with reference to FIGS. 5 and 6.

FIG. 5 is a diagram illustrating a dead time TD1 when the opening degree of the electric valve 32 according to the present embodiment changes from the fully closed position to the opening direction. FIG. 6 is a diagram illustrating a dead time TD2 when the opening degree of the electric valve 32 according to the present embodiment changes from the fully open position to the closed direction.

The reference change pattern BP1 in FIG. 5 and the reference change pattern BP2 in FIG. 6 are the same patterns as the reference change pattern BP1 and the reference change pattern BP2 described in FIG. The horizontal axis of FIGS. 5 and 6 indicates the time (seconds), and the vertical axis indicates the opening degree (%) of the electric valve 32. In FIG. 5, the command signal output unit 21 continuously outputs the command signal MV (first command signal) until the time t10 to t20. The time from the time t10 when the output of the first command signal is turned on to the time t20 when the output of the first command signal is turned off is hereinafter referred to as the travel time TR1. Of the travel time TR1 of the time t10 to t20, although the first command signal for changing the position of the electric valve 32 in the opening direction is issued during the time t10 to t11, the electric valve is actually a motorized valve. Wasted time TD1 occurs in which the opening degree of 32 does not change.

The effective time calculation unit 223 calculates the dead time TD1 based on the start timing of the output of the first command signal and the start timing of the change in the opening degree of the electric valve 32. That is, the effective time calculation unit 223 calculates the dead time TD1 from the time when the first command signal is output to the time when the change in the opening degree of the electric valve 32 starts.

Further, in FIG. 6, the command signal output unit 21 continuously outputs the command signal MV (second command signal) from the time t30 to t40. The time from the time t30 when the second command signal is turned on to the time t40 when the second command signal is turned off is hereinafter referred to as travel time TR2. Of the travel time TR2 of the time t30 to t40, although the second command signal for changing the position of the electric valve 32 in the opening direction is issued during the time t30 to t31, the electric valve is actually a motorized valve. Wasted time TD2 occurs in which the opening degree of 32 does not change.

The effective time calculation unit 223 is based on the start timing of the output of the second command signal and the start timing of the change in the opening degree of the electric valve 32, and the waste time TD2 from the fully opened state to the change in the opening degree of the electric valve 32. Is calculated. That is, the effective time calculation unit 223 calculates the dead time TD2 from the time when the second command signal is output to the time when the change in the opening degree of the electric valve 32 starts. As a result, the regulator 2 can acquire the information necessary for calculating the time during which the electric valve 32 is substantially operated from the start to the end of the output of the command signal MV.

In the following, the waste time TD1 and the waste time TD2 may be referred to as the first waste time. Further, the waste time TD1 and the waste time TD2 may be collectively referred to as a waste time TD. The waste time TD is generated by the frictional force related to the driving of the motor 31, and for example, when the motor 31 starts to be driven from the stopped state, the time required for the driving force to become larger than the frictional force around the shaft. Is. The lengths of the dead time TD1 and TD2 are basically different. This is because the torque is often different between the forward rotation and the reverse rotation of the motor. The dead time TD is held in the storage device 23.

Further, in the following, the above-mentioned travel time TR1 and travel time TR2 may be collectively referred to as a travel time TR. The effective time calculation unit 223 calculates the effective time TE, which is the time when the electric valve 32 is substantially operated, by subtracting the dead time TD from the travel time TR.

It has been described that the effective time calculation unit 223 calculates the first waste time (waste time TD1 and TD2) from the fully closed state to the fully open state of the electric valve 32. On the other hand, the effective time calculation unit 223 may calculate the waste time TD3 and the waste time TD4. The waste time TD3 is a waste time when the current change direction of the electric valve 32 and the immediately preceding change direction are the same when the electric valve 32 is in the middle position from the fully closed state to the fully open position. The waste time TD4 is a waste time when the current change direction of the electric valve 32 and the immediately preceding change direction are different when the electric valve 32 is in the middle position from the fully closed state to the fully open position.

Waste time TD3 and waste time TD4 are basically different times. Specifically, the waste time TD4 is longer than the waste time TD3. This is because it takes time for the motor to be driven because the rotation direction of the motor 31 is opposite. In the following, the waste time TD3 and the waste time TD4 may be collectively referred to as the second waste time. Further, the waste time TD3 and the waste time TD4 may be collectively referred to as the waste time TD together with the above-mentioned waste time TD1 and TD2.

Further, the second waste time is shorter than the first waste time. The effective time calculation unit 223 calculates, for example, the second waste time as half (1/2) of the first waste time.

The effective time calculation unit 223 calculates the dead time TD in this way, and reduces the dead time TD from the travel time TR, which is the length of time that the output of one command signal is continued, so that the electric valve 32 can be operated. The effective time TE, which is the substantially operating time, is calculated. As a result, the regulator 2 can calculate an accurate effective time TE by using the waste time TD regardless of the position of the electric valve 32 from the fully closed position to the fully open position.

<A-4. Function of state estimation unit (judgment unit)>
Returning to FIG. 2, the state estimation unit 22 uses the change amount of the reference change pattern BP as a reference based on the follow-up degree P3 calculated by the change amount calculation unit 221 and the effective time TE calculated by the effective time calculation unit 223. The degree of follow-up per unit time is calculated.

The determination unit 225 determines whether or not the electric valve 32 is in a predetermined abnormal state from the degree of deviation based on the degree of follow-up per unit time. Thereby, the regulator 2 can determine the state of the electric valve 32 when controlling the target value SV. Further, the controller 2 can identify at least one of the causes of the difference between the target value SV and the controlled variable PV.

<A-5. Summary>
In this way, the command signal output unit 21 of the controller 2 receives the input of the target value SV acquired from the terminal used by the user and the control amount PV acquired from the control target 4. The command signal output unit 21 outputs a command signal MV based on the target value SV and the control amount PV to the control valve 3. The change amount calculation unit 221 of the state estimation unit 22 acquires a feedback signal FB indicating a change in the voltage of the potentiometer 34 due to the rotation of the motor 31 based on the command signal MV, and uses the current change amount of the opening degree of the electric valve 32. The amount of change P1 of a certain measurement opening is calculated.

The change amount calculation unit 221 of the state estimation unit 22 opens the measurement opening change amount P1 indicating the change amount of the current opening degree of the electric valve 32 as a reference opening indicating the change amount of the normal opening degree of the electric valve 32. By dividing by the change amount P2 of the degree, the follow-up degree P3 indicating the ratio of the change amount of the current opening degree to the change amount of the opening degree at the normal time of the electric valve 32 is calculated. The change amount P2 of the reference opening degree is the change amount of a certain section (time) in the reference change pattern of the valve opening degree of the electric valve 32 acquired by the calibration. The specification of the change amount P2 of the reference opening with respect to the change amount P1 of the measurement opening is the current position of the electric valve 32 at the time when the command signal MV for one time is output in the change amount P1 of the measurement opening and one time. The command signal MV is based on the length of time the output has measured.

The effective time calculation unit 223 of the state estimation unit 22 calculates the waste time TD based on the start timing of the output of the command signal MV for one time and the start timing of the change in the opening degree of the electric valve 32. The effective time calculation unit 223 calculates the effective time TE, which is the time when the electric valve 32 is substantially operated, by subtracting the dead time TD from the travel time TR indicating the length of time that the output is continued.

The determination unit 225 determines whether the state of the electric valve 32 is an abnormal state based on the follow-up degree PT per unit time based on the follow-up degree P3 and the effective time TE, and the abnormality determination threshold value 23a which is a predetermined threshold value. Judge whether or not. The determination unit 225 determines that the state of the electric valve 32 is an abnormal state, for example, when the follow-up degree PT per unit time is less than the abnormality determination threshold value 23a. In other words, the determination unit 225 determines that the state of the electric valve 32 is an abnormal state, for example, when the degree of deviation per unit time is equal to or higher than the abnormality determination threshold value 23a. Thereby, the regulator 2 can determine the state of the electric valve 32 when controlling the target value SV. Further, the controller 2 can identify at least one of the causes of the difference between the target value SV and the controlled variable PV.

<B. Specific example of abnormality judgment processing>
<B-1. Explanation of the amount of change in the reference opening and the amount of change in the resistance value>
Next, a specific example of the abnormality determination process will be described in detail with reference to FIGS. 7 and 8. FIG. 7 is a diagram illustrating a change amount P2 of a reference opening degree and a change amount of a resistance value according to the present embodiment. The horizontal axis of FIG. 7 indicates the time (seconds), and the left side of the vertical axis indicates the opening degree (%) of the electric valve 32. The right side of the vertical axis shows the resistance value (Ω).

The effective time calculation unit 223 is the length of the continuous time (travel) of the first command signal from when the first command signal is turned on at time t10 to when the first command signal is turned off at time t20. Calculate the time TR1). The effective time calculation unit 223 calculates the effective time TE (time t11 to t20) obtained by subtracting the waste time TD (time t10 to t11) from the travel time TR1 (time t10 to t20).

The effective time calculation unit 223 selects the dead time used for calculating the effective time from the plurality of wasted times according to the current position of the electric valve 32 at the time when the command signal MV for one time is output. Specifically, when the current position of the electric valve 32 at the time when the command signal MV for one time is output is fully closed, for example, the effective time calculation unit 223 calculates the effective time TE among the dead times TD1 to TD4. The waste time TD1 used for is selected. The waste time TD1 is the waste time when the opening degree of the electric valve 32 changes from the fully closed state.

Specifically, when the current position of the electric valve 32 at the time when the command signal MV for one time is output is fully open, for example, the effective time calculation unit 223 calculates the effective time TE among the dead times TD1 to TD4. Select the waste time TD2 used for. This is a dead time when the opening degree of the electric valve 32 changes from the fully open state. As a result, when the current position of the electric valve 32 at the time when the output of the command signal MV is started is the fully closed or fully open position, the regulator 2 can appropriately select the dead time according to the position. The regulator 2 can select the dead time according to each position when the position of the electric valve 32 is the fully closed position and the fully open position. Further, the regulator 2 can select the information necessary for calculating the effective time TE when the position of the electric valve 32 is the fully closed position or the fully open position.

The effective time calculation unit 223 describes the current position of the electric valve 32 at the time when the command signal MV for one time is output, the current change direction of the electric valve 32 instructed by the command signal MV for one time, and the command signal for one time. The waste time TD used for calculating the effective time TE is selected from the plurality of waste time TDs according to the change direction immediately before the electric valve 32 instructed by the MV. Specifically, in the effective time calculation unit 223, the current position of the electric valve 32 at the time when one command signal MV is output is, for example, a position in the middle of fully closed to fully open, and one command signal MV is generated. When the current change direction of the instructed electric valve 32 is the open direction and the change direction immediately before the electric valve 32 instructed by one command signal MV is the open direction, the dead time TD3a (TD3) is calculated as the effective time TE. Select as the wasted time used for. The waste time TD3 is a waste time when the position of the electric valve 32 changes in the same direction as the immediately preceding change direction at a position in the middle of fully closed to fully open.

Specifically, the effective time calculation unit 223 has a command signal for one time when the current position of the electric valve 32 at the time when the command signal MV for one time is output is, for example, a position in the middle of being fully closed to fully opened. When the current change direction of the electric valve 32 instructed by the MV is the open direction and the change direction immediately before the electric valve 32 instructed by one command signal MV is the closed direction, the waste time TD4a (TD4) is used as the effective time TE. Select as the wasted time used to calculate. The waste time TD4 is a waste time TD when the position of the electric valve 32 changes in a direction different from the immediately preceding change direction at a position in the middle of fully closed to fully open. As described above, the regulator 2 can select an appropriate dead time TD according to the changing direction when the electric valve 32 is located in the middle from the fully closed state to the fully open state. Further, the regulator 2 can select the information necessary for calculating the effective time TE when the position of the electric valve 32 is in the middle of being fully closed to fully opened.

In FIGS. 7 and 8, the first command signal is turned off immediately before the time t14 between the times t10 and t20, and is turned on at the time t14, so that the dead time TD3a is generated in the times t14 to t14a. There is. As described above, the change in the opening degree of the electric valve 32 is indicated by the reference change pattern BP broken line. The reference change pattern BP will be described by taking the reference change pattern BP1 as an example.

The change amount calculation unit 221 of the state estimation unit 22 divides the time t10 to t20 of the reference change pattern BP1 into, for example, 10 equal parts, and calculates the change amount P2 of the reference opening degree in each section. Specifically, the change amount calculation unit 221 is in each time section of time t10 to t11, time t11 to t12, time t12 to t13, ..., Time t18 to t19, and time t19 to t20. The amount of change P2 of the reference opening is calculated. Specifically, the change amount calculation unit 221 calculates the change amount (voltage change amount) of the resistance of the variable resistor of the potentiometer 34, and calculates the change amount P2 of the reference opening corresponding to this.

The change amount calculation unit 221 calculates the change amount 0Ω of the resistance value during the time t10 to t11, and calculates that the change amount P2 of the reference opening degree of the electric valve 32 during this period is 0%. This time is a waste time TD because the amount of change in the opening degree is 0% even though the first command signal is in the ON state. Further, the change amount calculation unit 221 calculates the change amount of the resistance value from each section after the time t11, and calculates the change amount P2 of the reference opening degree of the electric valve 32 in each section. For example, the change amount calculation unit 221 calculates the change amount r5Ω of the resistance value between the times t15 and t16, and sets the change amount P2 of the reference opening degree of the electric valve 32 corresponding to the change amount of the resistance value by 10%. Calculated as (opening 40% → 50%). As another example, the change amount r6Ω of the resistance value during the time t16 to t17 is calculated, and the change amount P2 of the reference opening degree of the electric valve 32 corresponding to the change amount of the resistance value is set to 10% (open). Calculate as degree 50% → 60%). In this way, the change amount calculation unit 221 calculates the change amount of the resistance value in each section, and stores the change amount P2a of the reference opening degree corresponding to the change amount of the resistance value in the storage device 23. The amount of change in the resistance value is a value corresponding to the amount of change in the voltage of the feedback signal FB described above.

Here, the reference change pattern BP1 shown by the broken line in FIGS. 7 and 8 is a non-linear curve. The change amount calculation unit 221 performs a process of approximating the reference change pattern BP1 to a straight line by performing linear interpolation on the curve of each section. The change amount calculation unit 221 approximates the curve to a straight line by performing linear interpolation on the curve between the resistance value Q1 at the time t17 and the resistance value Q2 at the time t18, for example. By performing such linear interpolation in other sections, the change amount calculation unit 221 executes a polygonal line approximation that approximates a curve having non-linearity by connecting a plurality of straight lines, and calculates a polygonal line transition line PL. Thereby, the regulator 2 can easily calculate the amount of change in the resistance value with respect to the amount of change in the opening degree of the electric valve 32.

<B-2. Abnormality judgment processing>
Next, a specific example of the abnormality determination process will be described with reference to FIG. FIG. 8 is a diagram illustrating a specific example of the abnormality determination process according to the present embodiment. As shown in FIG. 8, the start position of the current opening change of the electric valve 32 will be described as being in the middle position from the fully closed state to the fully open position. Specifically, the electric valve 32 is at the position of the opening 22%, which is 22% moved in the opening direction from the opening 0% in the fully closed state, and the travel time corresponds to the time t14 to 17 (travel time TR3). ).

The change amount calculation unit 221 has an opening degree of 22% at the position where the change in the opening degree of the electric valve 32 starts with respect to the change amount P1 of the measurement opening degree, and in the case of the travel time TR3, the resistance values change from Q3 to Q4. The measurement pattern RL is obtained, and the change amount R1 (r4b + r5) of the resistance value is calculated. The change amount calculation unit 221 specifies the change amount section of the reference change pattern BP1 as the time t14 to t17 from the current position (22%) of the electric valve 32 and the travel time TR3. The amount of change in the resistance value R2 (r4b + r5 + r6) from the resistance values Q3 to Q5 in this section is calculated.

Since the dead time TD3a is between the times t14 and t14a, the amount of change in resistance r4a is 0Ω. In this waste time TD3a, for example, the command signal output unit 21 changes the electric valve 32 in the opening direction, for example, immediately before the time t14 during the time t10 to t20 (first command signal ON to OFF). It is calculated by turning off the output of the command signal and turning on the output of the first command signal at time t14. Further, half the time of the waste time TD1 may be set as the waste time TD3a.

The effective time calculation unit 223 calculates the effective time TE3 by subtracting the waste time TD3 from the travel time TR3 from ON to OFF of the first command time.

The state estimation unit 22 calculates (P1 / P2) = P3 and P3 / TE3 = BT. The state estimation unit 22 divides the change amount P1 of the measurement opening corresponding to the change amount R1 of the resistance by the change amount P2 of the reference opening degree corresponding to the change amount R2 of the resistance to calculate the follow-up degree P3. Further, the state estimation unit 22 divides the follow-up degree P3 by the effective time TE3 to calculate the follow-up degree PT per unit time.

The determination unit 225 determines whether or not the electric valve 32 is in a predetermined abnormal state based on the follow-up degree PT per unit time. Specifically, the determination unit 225 reads out the abnormality determination threshold value 23a stored in the storage device 23. For example, the determination unit 225 determines that the state of the electric valve 32 is abnormal when the follow-up degree PT per unit time is less than the abnormality determination threshold value 23a, and the electric valve when the valve follow-up degree PT is equal to or higher than the abnormality determination threshold value. It is determined that the state of 32 is normal. In other words, the determination unit 225 determines that the state of the electric valve 32 is abnormal when the degree of deviation per unit time is, for example, the abnormality determination threshold 23a or more, and the electric valve when the degree of deviation is less than the abnormality determination threshold. It is determined that the state of 32 is normal. Thereby, the regulator 2 can determine the state of the electric valve 32 when controlling the target value SV. Further, the controller 2 can identify at least one of the causes of the difference between the target value SV and the controlled variable PV.

<C. Hardware configuration>
FIG. 9 is a block diagram showing a hardware configuration example of the adjustment system 1 according to the present embodiment. With reference to FIG. 9, the regulation system 1 is a system that regulates the temperature in the controlled object 4 such as a furnace, and includes a regulator 2, a control valve 3, and an alarm 5.

The regulator 2 detects the temperature of the controlled object 4 and issues a command to the control valve 3. Therefore, the control valve 3 becomes an operating element of the controller 2. The regulator 2 includes a processor 20, a storage device 23, a constant current circuit 24, an AD (Analog-to-Digital) converter 25, a first switch unit SW1, a second switch unit SW2, and a detection unit 30. And the alarm signal output unit 50.

The processor 20 reads the program stored in the storage device 23 and executes the process, thereby using the electric valve 32 as an operating element and controlling the controlled object 4. The processor 20 reads and executes the command signal output program 21a stored in the storage device 23. Specifically, in the processor 20, the control amount PV becomes the target value SV by the target value SV input from the external terminal (not shown) operated by the user and the control amount PV received from the control target 4. A command signal MV instructing an approaching operation amount is output to either the first switch unit SW1 or the second switch unit SW2.

The first switch unit SW1 and the second switch unit SW2 switch the opening and closing of the electric valve 32. In the present embodiment, the first switch unit SW1 and the second switch unit SW2 include an open operation relay 131 and a closed operation relay 132. The first switch unit SW1 and the second switch unit SW2 set either the open operation relay 131 or the closed operation relay 132 to ON (conducting state) based on the command signal MV from the processor 20. When the open operation relay 131 is turned on, the first command signal is output to the control valve 3, and when the closed operation relay 132 is turned on, the second command signal is output.

The target value SV is, for example, the desired temperature in the controlled object 4 of a furnace or the like, and the controlled variable PV is the actual temperature in the furnace. Further, in the command signal MV, in order to reduce the difference between the desired temperature in the furnace and the actual temperature, either the first switch section SW1 or the second switch section SW2 is changed from the OFF state to the ON state. Then, the motor 31 included in the control valve 3 is driven.

The controlled object 4 is provided with a thermocouple 41, and the detection unit 30 detects and controls the temperature corresponding to the actual temperature of the controlled object 4 based on the thermoelectromotive force generated between the terminals of the thermocouple 41. It is output to the processor 20 as a quantity PV.

The control valve 3 adjusts the flow rate of the fluid supplied to the controlled object 4 based on the command signal MV from the regulator 2. The control valve 3 has a motor 31, an electric valve 32, a pipe 33, and a potentiometer 34. The motor 31 rotates in a certain direction (for example, forward rotation) when the first switch unit SW1 is turned on by the first command signal included in the command signal MV. Further, the motor 31 rotates (for example, reverses) in a direction opposite to a certain direction when the second switch unit SW2 is turned on by the second command signal included in the command signal MV. The first command signal and the second command signal are signals that are intermittently output from the command signal output unit 21.

When the command signal output unit 21 outputs a signal to one of the switches, the command signal output unit 21 does not output the signal to the other switch. In this way, the motor 31 rotates forward or reverse depending on the duration of one command signal MV output from the command signal output unit 21, so that the electric valve 32 is in either the open direction or the closed direction. Move in that direction.

The electric valve 32 moves in the opening direction by the forward rotation of the motor based on the first command signal. By operating the electric valve 32 in the opening direction in this way, the flow rate of the gas flowing into the controlled object 4 through the pipe 33 increases. Further, the electric valve 32 moves in the closing direction by reversing the motor based on the second command signal. By operating the electric valve 32 in the closing direction in this way, the flow rate of the gas flowing into the controlled object 4 through the pipe 33 is reduced.

By adjusting the flow rate of gas in the pipe 33 by the operation of the electric valve 32, the thermal power of the burner 35 provided at one end of the pipe 33 on the control target 4 side is adjusted. Specifically, when the thermal power of the burner 35 is increased, the temperature in the controlled object 4 is increased, and when the thermal power of the burner is decreased, the temperature in the controlled object 4 is decreased. The controlled variable PV indicating the temperature adjusted in this way is output from the controlled object 4 to the processor 20.

Further, the voltage input from the potentiometer 34 to the processor 20 changes due to the rotation of the motor 31. The potentiometer 34 is a device that converts the amount of movement and the angle of rotation associated with the rotation of the motor 31 into a voltage, and is specifically a variable resistor 340. The variable resistor 340 has a slider (sliding terminal) W, a terminal C, and a terminal O, and the slider W slides between the terminal C and the terminal O in conjunction with the rotation of the motor 31. Move. The resistance value of the variable resistor 340 changes due to the sliding of the slider W. For example, when the electric valve 32 is controlled in the open direction, the slider W slides toward the terminal C, and when the electric valve 32 is controlled in the closed direction, the slider W slides toward the terminal O side. Sliding to. When the slider W reaches the terminal C, the position of the electric valve 32 becomes the fully open position, so that the rotation of the motor 31 is stopped. When the slider W reaches the terminal O, the position of the electric valve 32 becomes the fully closed position, so that the rotation of the motor 31 is stopped.

The potentiometer 34 including the variable resistor 340 outputs a feedback signal FB according to the amount of movement generated by the rotation of the motor 31. Specifically, the potentiometer 34 outputs a feedback signal FB to the AD converter 25 according to the amount of change in the opening degree of the electric valve 32 whose opening degree changes as the motor 31 rotates.

The AD converter 25 is connected to each of the above three terminals W, C, and O of the variable resistor 340. The AD converter 25 detects the voltage between the terminal W and the terminal C of the variable resistor 340 based on the feedback signal FB. The voltage detected by the AD converter 25 is output to the processor 20. Further, a current passing between the terminal O and the terminal C of the variable resistor 340 is supplied from the constant current circuit 24.

The processor 20 reads and executes the state estimation program 22a stored in the storage device 23. Specifically, the processor 20 estimates the state of the electric valve 32 based on the command signal MV output from the command signal output unit 21 and the feedback signal FB output from the potentiometer 34.

The processor 20 calculates the follow-up degree P3 based on the change amount P1 of the measurement opening degree and the change amount P2 of the reference opening degree.

Further, the processor 20 calculates the effective time TE by subtracting the dead time TD from the travel time TR. The processor 20 divides the follow-up degree P3 by the effective time TE to calculate the follow-up degree PT per unit time.

The processor 20 determines whether or not the electric valve 32 is in a predetermined abnormal state based on the follow-up degree PT (the degree of deviation per unit time) of the electric valve 32. Specifically, the processor 20 reads out the abnormality determination threshold value 23a stored in the storage device 23, and for example, the follow-up degree PT per unit time is less than the speed of the abnormality determination threshold value 23a (in the case of the electric valve 32). Further, the processor 20 determines that the state of the electric valve 32 is normal when the follow-up degree PT per unit time is equal to or greater than the abnormality determination threshold value.

When the processor 20 determines that the state of the electric valve 32 is abnormal, the processor 20 outputs an instruction signal to the alarm signal output unit 50. The alarm signal output unit 50 that has received the instruction signal from the processor 20 outputs a signal related to the warning to the alarm device 5 with an image, a sound, or the like to the user. The alarm device 5 receives the signal output from the alarm signal output unit 50 and outputs a warning to the user. As a result, the regulator 2 can surely notify the user that the electric valve 32 is in an abnormal state.

<D. Processor control structure>
The control structure of the processor 20 of the controller 2 will be described with reference to FIG. FIG. 10 is a flowchart showing a part of the processing executed by the processor 20 according to the present embodiment. The processor 20 is realized by reading and executing the command signal output program 21a, the state estimation program 22a, the reference change pattern BP, and the abnormality determination threshold value 23a stored in the storage device 23.

In the process of step S101, the processor 20 calculates the follow-up degree PT per unit time based on the follow-up degree P3 and the effective time TE.

In the process of step S103, the processor 20 determines whether or not the electric valve 32 is in a predetermined abnormal state based on the follow-up degree PT per unit time. Specifically, the processor 20 reads out the abnormality determination threshold value 23a stored in the storage device 23, and controls if the follow-up degree PT per unit time is less than the abnormality determination threshold value 23a (YES in step S103). Switch to step S105. Further, when the follow-up degree PT per unit time is equal to or higher than the abnormality determination threshold value 23a (NO in step S103), this process is terminated.

In the process of step S105, when the processor 20 determines that the state of the electric valve 32 is abnormal, the processor 20 outputs an instruction signal to the alarm signal output unit 50. The alarm signal output unit 50 that has received the instruction signal from the processor 20 outputs a signal related to the warning to the user by an image, a sound, or the like to the alarm device 5. The alarm device 5 receives a signal from the alarm signal output unit 50 and outputs a warning to the user. As a result, the regulator 2 can surely notify the user that the electric valve 32 is in an abnormal state.

Next, the process of setting the dead time TD will be described with reference to FIG. FIG. 11 is a flowchart showing a part of the process for setting the dead time TD executed by the processor 20 according to the present embodiment.

In the process of step S201, the processor 20 determines whether or not to start setting the dead time TD. Specifically, when the processor 20 calculates the change amount R4 of the resistance value per unit time in the process of step S101 described with reference to FIG. 10, the process of step S201 is executed. When the processor 20 determines that the setting of the dead time TD is started (YES in step S201), the processor 20 switches the control to step S203. Further, when the processor 20 determines that the dead time TD setting is not started (NO in step S201), the processor 20 ends this process.

In the process of step S203, the processor 20 determines whether or not the current position of the electric valve 32 is a position in the middle from the fully closed position to the fully open position. When the current position is in the middle of the process from fully closed to fully open (YES in step S203), the processor 20 switches the control to step S211. When the current position is not in the middle of the position from fully closed to fully opened (NO in step S203), the processor 20 switches the control to step S205.

In the process of step S205, the processor 20 determines whether or not the position of the electric valve 32 is a fully closed position. When the position of the electric valve 32 is in the fully closed position (YES in step S205), the processor 20 switches the control to step S207. When the position of the electric valve 32 is in the fully open position (NO in step S205), the processor 20 switches the control to step S209.

In the process of step S207, since the current position of the electric valve 32 is the fully closed position, the processor 20 selects the dead time TD1 (fully closed → open direction) and ends the process.

In the process of step S209, since the current position of the electric valve 32 is the fully open position, the processor 20 selects the dead time TD2 (fully open → closed direction) and ends the process.

In the process of step S211th, the processor 20 determines whether or not the current changing direction of the electric valve 32 is the opening direction. When the current change direction is the open direction (YES in step S211), the processor 20 switches the control to step S213. The processor 20 switches control to step S219 when the current change direction is not the open direction, that is, the closed direction (NO in step S211).

In the process of step S213, the processor 20 determines whether or not the change direction immediately before the electric valve 32 is the open direction. When the immediately preceding change direction is the open direction (YES in step S213), the processor 20 switches the control to step S215. The processor 20 switches the control to step S217 when the immediately preceding change direction is not the open direction, that is, the closed direction (NO in step S213).

In the process of step S215, the processor 20 wastes time from the start timing of the output of the command signal MV (first command signal) (start timing of the travel time TR) to the timing when the opening degree of the electric valve 32 changes. The time is set as TD3a and the process ends. This waste time TD3a is a waste time when the position of the electric valve 32 is in the middle between fully closed and fully opened, the immediately preceding change direction is the open direction, and the current change direction also changes in the open direction.

In the process of step S217, the processor 20 sets the dead time from the start timing of the output of the command signal MV (first command signal) to the timing when the opening degree of the electric valve 32 changes as the dead time TD4a, and performs the process. finish. This waste time TD4a is a waste time when the position of the electric valve 32 is in the middle between fully closed and fully opened, the immediately preceding change direction is the closing direction, and the current changing direction changes to the opening direction.

In the process of step S219, the processor 20 determines whether or not the change direction immediately before the electric valve 32 is the open direction. When the immediately preceding change direction is the open direction (YES in step S219), the processor 20 switches the control to step S221. The processor 20 switches the control to step S223 when the immediately preceding movement direction is not the open direction, that is, the closed direction (NO in step S219).

In the process of step S221, the processor 20 sets the dead time from the start timing of the output of the command signal MV (second command signal) to the timing when the opening degree of the electric valve 32 changes as the dead time TD4b, and performs the process. finish. This waste time TD4b is a waste time when the position of the electric valve 32 is in the middle between fully closed and fully opened, the immediately preceding change direction is the open direction, and the current change direction changes to the closed direction.

In the process of step S223, the processor 20 sets the dead time from the start timing of the output of the command signal MV (second command signal) to the timing when the opening degree of the electric valve 32 changes as the dead time TD3b, and performs the process. finish. This waste time TD3b is a waste time when the electric valve 32 is in the middle position between fully closed and fully opened, the immediately preceding moving direction is the closing direction, and the current moving direction also moves in the closing direction. ..

In this way, the processor 20 accurately calculates the effective time TE by setting the dead time TD according to the current and immediately preceding movement conditions of the electric valve 32, and accurately determines the state of the opening degree of the electric valve 32. I can judge.

Next, a specific example of the process in which the processor 20 sets the dead time TD and calculates the effective time TE will be described with reference to FIG. FIG. 12 is a diagram illustrating a process of calculating the effective time TE of the processor 20 according to the present embodiment.

The processor 20 has an operating state derivation unit 201, a waste time setting unit 202, a waste time storage unit 203, an operation time calculation unit 204, and an effective time calculation unit as functional units for calculating the effective time of the state estimation program 22a. 223 and included.

The operating state derivation unit 201 determines the immediately preceding moving direction and the current moving direction of the electric valve 32 from the command signal MV regarding the current moving direction of the electric valve 32 and the command signal MV (-1) regarding the immediately preceding moving direction. Derived. The operating state deriving unit 201 derives, for example, that the immediately preceding moving direction is the closed direction and the current moving direction is the open direction.

The waste time setting unit 202 is stored in the waste time storage unit 203 based on the movement direction (closed direction) immediately before the electric valve 32 derived by the operation state derivation unit 201 and the current movement direction (open direction). The waste time TD1 is selected from a plurality of types of waste time TDs (for example, waste time TD1 to TD4b).

The waste time storage unit 203 is a memory that expands the information read from the storage device 23, and is composed of a volatile storage device such as a DRAM (Dynamic Random Access Memory) or a SRAM (Static Random Access Memory).

The operation time calculation unit 204 calculates a travel time TR indicating the length of time that the output of the command signal MV regarding the current moving direction continues.

The effective time calculation unit 223 calculates the effective time TE obtained by subtracting the waste time TD1 from the travel time TR. As a result, the processor 20 can calculate an accurate time from the actual start of operation of the electric valve 32 to the end of operation.

<E. Modification example>
In the present embodiment, in order to control the temperature in the furnace with the controlled object 4 as the furnace as described above, the adjustment of the flow rate of the gas discharged to the controlled object 4 with the fluid as the gas has been described as an example. The control target 4 is not limited to this, and may target another (for example, a water tank or the like). In this case, the fluid discharged to the controlled object 4 is water, and the flow rate of water may be adjusted in order to control the water level in the water tank.

In the present embodiment, the change amount calculation unit 221 has described that the time of the reference change pattern BP is divided into 10 with respect to the setting of the section for calculating the change amount P2 of the reference opening degree. The number of divisions is exemplary and may be greater than or less than 10. Further, the change amount calculation unit 221 may select the time of the change amount P2 of the reference opening degree corresponding to the time of the change amount P1 of the measurement opening degree from the reference change pattern BP without dividing. For example, the change amount calculation unit 221 outputs from the time (ON time) when the command signal MV is output once when the change amount P1 of the measurement opening occurs in the time t10 to t20 from the fully closed to the fully open. The time until the end time (OFF time) and the same time may be selected between the times t10 to t20, and the change amount P2 of the reference opening degree at that time may be used as a comparison target.

In the present embodiment, when the change amount P2 of the reference opening degree has non-linearity, it has been described that the change amount of each section is linearly interpolated and approximated by a polygonal line. On the other hand, when the change amount P2 of the reference opening degree has linearity, the change amount of each section may be used as it is without executing the polygonal line approximation process.

Further, in the present embodiment, as a process of determining the state of the electric valve 32 when controlling the target value, the follow-up degree P3 obtained by dividing the measured opening change amount P1 by the reference opening change amount P2 is obtained. The process of comparing the follow-up degree PT per unit time divided by the effective time TE with the threshold value has been described. On the other hand, the state of the electric valve 32 may be determined by another processing method. For example, the value obtained by dividing the change amount P1 of the measurement opening degree by the effective time TE may be compared with the threshold value to determine whether or not the electric valve 32 is in an abnormal state.

In the present embodiment, the amount of change in the reference opening from fully closed to fully open (the amount of change in the reference opening P2a) of the electric valve 32 has been described with reference to FIGS. 7 and 8, but the electric valve 32 has been described. Regarding the amount of change in the reference opening from fully open to fully closed (change in reference opening P2b), the time is divided into a plurality of sections, and the amount of change in the opening of the electric valve 32 is changed from the change in resistance value for each section. The process of calculating the above, the process of approximating the polygonal line, and the like are performed in the same manner as those described with reference to FIGS. 7 and 8.

In the present embodiment, it has been described that the change amount calculation unit 221 performs a process of approximating the reference change pattern BP1 to a straight line by performing linear interpolation on the curve of each section. On the other hand, the change amount calculation unit 221 may perform linear interpolation on the measurement pattern RL to perform a process of approximating a straight line.

In the present embodiment, regarding the waste time TD, the waste time TD1 (fully closed → open direction), the waste time TD2 (fully open → closed direction), the waste time TD3a (open direction → open direction), and the waste time TD3b (closed direction →). A total of six examples are shown: (closed direction), dead time TD4a (closed direction → open direction), and dead time TD4b (open direction → closed direction). That is, (1) the group of waste time TD1 and TD2 in which the opening degree of the electric valve 32 changes from fully closed or fully opened, and (2) the direction of change immediately before and present is the same at the position in the middle from fully closed to fully opened. Three types of time TD3 groups and (3) waste time TD4 groups having different directions of change immediately before and at the position in the middle from fully closed to fully open have been described as examples. Then, when controlling the target value SV, when determining the state of the electric valve 32, all three types may be implemented, or two types (1) and (2) (four wasted times). May be used to determine the state of the motorized valve 32.

<F. Addendum>
As described above, the present embodiment includes the following disclosures.

[Structure 1]
A controller that controls a controlled object (4) by using an electric valve (32) that receives a first command signal and operates in the open direction and that receives a second command signal and operates in the closed direction as an operating element. (2)
Either the first command signal or the second command signal is intermittently used so that the control amount (PV) acquired from the control target (4) matches the preset target value (SV). Command signal output unit (21) to output to
A holding portion (23) that holds a reference change pattern of the valve opening degree of the electric valve (32) acquired by prior calibration, and a holding portion (23).
The electric valve (32) is based on the command signal (MV) output from the command signal output unit (21) and the feedback signal (FB) indicating the degree of valve opening degree of the electric valve (32). It is equipped with a state estimation unit (22) that estimates the state.
The state estimation unit (22)
The change amount calculation unit (221) that calculates the change amount (P3) of the valve opening degree of the electric valve (32) in response to one command signal intermittently output from the command signal output unit (21). When,
The electric valve is obtained by acquiring the length of time during which the output of the command signal (MV) for one time is continued, and by subtracting a predetermined dead time (TD) from the length of time during which the output is continued. The effective time calculation unit (223) for calculating the effective time (TE), which is the time during which (32) is substantially operated, and
Based on the amount of change in the valve opening degree (P3) of the electric valve (32), the amount of change corresponding to the command signal (MV) for one time in the valve opening degree change pattern, and the effective time (TE). Judgment unit for determining whether or not the electric valve (32) is in a predetermined abnormal state based on the degree of deviation per time based on the amount of change in the valve opening change pattern calculated by A regulator, including (225).

[Structure 2]
The effective time calculation unit (223) has the effective time (TE) out of a plurality of waste times (TD) according to the current position of the electric valve (32) at the time when the command signal for one time is output. The regulator according to configuration 1, which selects the dead time (TD) used for the calculation of).

[Structure 3]
The plurality of wasted times (TD) are the wasted time when the position of the electric valve (32) changes from the fully closed position and the opening from the position where the electric valve (32) is fully open. The regulator according to configuration 2, which includes the wasted time when changes in.

[Structure 4]
The effective time calculation unit (223) is the current position of the electric valve (32) at the time when the command signal for one time is output, and the electric valve (32) indicated by the command signal (MV) for one time. The effective time (TE) out of the plurality of waste times (TD) according to the current change direction of the above and the change direction immediately before the electric valve (32) indicated by the one command signal (MV). The regulator according to the configuration 1 for selecting the dead time (TD) used for the calculation of).

[Structure 5]
The plurality of waste times (TD) are the waste time when the position of the electric valve (32) changes in the same direction as the immediately preceding change direction at a position in the middle of fully closed to fully open, and the position of the electric valve. The regulator according to configuration 4, which includes a dead time when the position changes in a different direction from the immediately preceding change direction at the intermediate position.

[Structure 6]
The change amount calculation unit (221) continued to output the current position of the electric valve (32) at the time when the command signal (MV) for one time was output and the command signal (MV) for one time. The regulator according to any one of configurations 1 to 5, which specifies a section of the amount of change of the reference change pattern (BP) corresponding to the one command signal (MV) based on the length of time. ..

[Structure 7]
The regulator according to the configuration 5, wherein the change amount calculation unit (221) approximates a plurality of straight lines having linearity when the valve opening degree change pattern is a curve having non-linearity.

[Structure 8]
The regulator according to any one of configurations 1 to 7, further comprising an alarm signal output unit (50) that outputs an alarm signal when the change amount calculation unit (221) determines that the abnormal state is present. ..

[Structure 9]
A controller that controls a controlled object (4) by using an electric valve (32) that receives a first command signal and operates in the open direction and that receives a second command signal and operates in the closed direction as an operating element. This is the adjustment method of (2).
Either the first command signal or the second command signal is intermittently used so that the control amount (PV) acquired from the control target (4) matches the preset target value (SV). Step (S101) to output to
A step of holding a reference change pattern of the valve opening degree of the electric valve (32) acquired by prior calibration, and a step of holding the reference change pattern.
The state of the electric valve (32) based on the command signal (MV) output by the step of intermittent output and the feedback signal (FB) indicating the degree of valve opening degree of the electric valve (32). With the step (S101) for estimating
The step (S101) for estimating the state is
A step (S101) for calculating the amount of change in the valve opening degree of the electric valve (32) according to one command signal (MV) intermittently output by the intermittent output step.
The electric valve is obtained by acquiring the length of time during which the output of the command signal (MV) for one time is continued, and by subtracting a predetermined dead time (TD) from the length of time during which the output is continued. The step (S101) for calculating the effective time (TE), which is the time in which (32) is substantially operated, and
Calculated based on the amount of change in the valve opening of the electric valve (32), the amount of change corresponding to the command signal (MV) for one time in the valve opening change pattern, and the effective time (TE). The step (S103) of determining whether or not the electric valve (32) is in a predetermined abnormal state based on the degree of deviation per time based on the amount of change in the valve opening change pattern. Adjustment methods, including.

[Structure 10]
An electric valve (32) that receives the first command signal and operates in the open direction and also receives the second command signal and operates in the closed direction.
A controller (2) that controls a controlled object (4) by using the electric valve (32) as an operating element.
Either the first command signal or the second command signal is intermittently used so that the control amount (PV) acquired from the control target (4) matches the preset target value (SV). Command signal output unit (21) to output to
A holding portion (23) that holds a reference change pattern of the valve opening degree of the electric valve (32) acquired by prior calibration, and a holding portion (23).
The electric valve (32) is based on the command signal (MV) output from the command signal output unit (21) and the feedback signal (FB) indicating the degree of valve opening degree of the electric valve (32). It is equipped with a state estimation unit (22) that estimates the state.
The state estimation unit (22)
The change amount calculation unit (221) that calculates the change amount of the valve opening degree of the electric valve (32) according to one command signal (MV) intermittently output from the command signal output unit (21). When,
The electric valve (32) is obtained by acquiring the length of time during which the output of the command signal for one time is continued and by subtracting a predetermined waste time (TD) from the length of time during which the output is continued. The effective time calculation unit (223) for calculating the effective time (TE), which is the time during which is substantially operated, and
Calculated based on the amount of change in the valve opening of the electric valve (32), the amount of change corresponding to the command signal (MV) for one time in the valve opening change pattern, and the effective time (TE). A determination unit (225) for determining whether or not the electric valve (32) is in a predetermined abnormal state based on the degree of deviation per time based on the amount of change in the valve opening change pattern. An adjustment system, including an adjuster (2) with and.

It should be considered that the embodiments disclosed this time are exemplary in all respects and not restrictive. The scope of the present invention is shown by the scope of claims rather than the above description, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

1 Adjustment system, 2 Controller, 3 Control valve, 4 Control target, 5 Alarm, 20 Processor, 21 Command signal output unit, 21a Command signal output program, 22 State estimation unit, 22a State estimation program, 23 Storage device, 23a Abnormality judgment threshold, 24 constant current circuit, 30 detector, 31 motor, 32 electric valve, 33 piping, 34 potentiometer, 35 burner, 41 thermocouple, 50 alarm signal output unit, 131 open operation relay, 132 closed operation relay, 201 Operating state derivation unit, 202 Waste time setting unit, 203 Waste time storage unit, 204 Operation time calculation unit, 221 Change amount calculation unit, 223 Effective time calculation unit, 225 Judgment unit, 340 Variable resistor, FB feedback signal, MV Command signal, PL fold line transition line, PV control amount, Q1, Q2, Q3, Q4, Q5 resistance value, SV target value, SW1 first switch part, SW2 second switch part, TD, TD1, TD2, TD3 TD4 wasted time, TE, TE3 effective time, TR, TR1, TR2, TR3 travel time, W slider.

Claims (9)

A regulator that controls a controlled object by using an electric valve that receives a first command signal and operates in the open direction and also receives a second command signal and operates in the closed direction as an operating element.
A command signal output unit that intermittently outputs either the first command signal or the second command signal so that the control amount acquired from the control target matches a preset target value.
A holding unit that holds a reference change pattern of the valve opening of the electric valve acquired by prior calibration, and a holding unit.
A state estimation unit for estimating the state of the electric valve based on a command signal output from the command signal output unit and a feedback signal indicating the degree of valve opening degree of the electric valve is provided.
The state estimation unit is
A change amount calculation unit that calculates the change amount of the valve opening degree of the electric valve according to one command signal intermittently output from the command signal output unit.
The electric valve was substantially operated by acquiring the length of time during which the output of the command signal for one time was continued and by subtracting a predetermined dead time from the length of time during which the output was continued. The effective time calculation unit that calculates the effective time, which is the time, and the effective time calculation unit
The reference change pattern calculated based on the change amount of the valve opening degree of the electric valve, the change amount of the valve opening degree corresponding to the one command signal of the reference change pattern, and the effective time. the amount of change based on the degree of deviation per hour on the basis, seen including a determination section that the electric valve to determine whether a predetermined abnormal condition,
The effective time calculation unit selects, among a plurality of the waste times, the waste time used for calculating the effective time according to the current position of the electric valve at the time when the command signal for one time is output. Knotting device. The plurality of waste times are the waste time when the opening of the electric valve changes from the fully closed position and the waste time when the opening of the electric valve changes from the fully open position. The regulator according to claim 1 , including the present invention. A regulator that controls a controlled object by using an electric valve that receives a first command signal and operates in the open direction and also receives a second command signal and operates in the closed direction as an operating element.
A command signal output unit that intermittently outputs either the first command signal or the second command signal so that the control amount acquired from the control target matches a preset target value.
A holding unit that holds a reference change pattern of the valve opening of the electric valve acquired by prior calibration, and a holding unit.
A state estimation unit for estimating the state of the electric valve based on a command signal output from the command signal output unit and a feedback signal indicating the degree of valve opening degree of the electric valve is provided.
The state estimation unit is
A change amount calculation unit that calculates the change amount of the valve opening degree of the electric valve according to one command signal intermittently output from the command signal output unit.
The electric valve was substantially operated by acquiring the length of time during which the output of the command signal for one time was continued and by subtracting a predetermined dead time from the length of time during which the output was continued. The effective time calculation unit that calculates the effective time, which is the time, and the effective time calculation unit
The reference change pattern calculated based on the change amount of the valve opening degree of the electric valve, the change amount of the valve opening degree corresponding to the one command signal of the reference change pattern, and the effective time. Including a judgment unit for determining whether or not the electric valve is in a predetermined abnormal state based on the degree of deviation per hour based on the amount of change.
The effective time calculation unit includes the current position of the electric valve at the time when the command signal for one time is output, the current change direction of the electric valve indicated by the command signal for one time, and the command for one time. depending on the change direction immediately before the electric valve which signal indicates, to select the dead time used for calculating the effective time of the plurality of the dead time, regulatory unit. The plurality of wasted times are the wasted time when the position of the electric valve changes in the same direction as the immediately preceding change direction at the position in the middle of fully closed to fully open, and the position of the electric valve immediately before is in the middle position. The regulator according to claim 3 , comprising a change direction of the head and a dead time when the head changes in a different direction. The change amount calculation unit is based on the current position of the electric valve at the time when the command signal for one time is output and the length of time for the output of the command signal for one time to continue. The regulator according to any one of claims 1 to 4 , which specifies an interval of a change amount of the reference change pattern corresponding to a command signal. The regulator according to any one of claims 1 to 5 , wherein the change amount calculation unit approximates a plurality of straight lines having linearity when the reference change pattern becomes a curve having non-linearity. The regulator according to any one of claims 1 to 6 , further comprising an alarm signal output unit that outputs an alarm signal when the determination unit determines that the abnormal state is present. An adjustment method executed by a regulator that controls a controlled object by using an electric valve that receives a first command signal and operates in the open direction and that receives a second command signal and operates in the closed direction as an operating element. And,
A step of intermittently outputting either the first command signal or the second command signal so that the control amount acquired from the control target matches a preset target value.
A step of holding a reference change pattern of the valve opening of the electric valve acquired by prior calibration, and a step of holding the reference change pattern.
The step includes a step of estimating the state of the motorized valve based on the command signal output by the step of intermittently outputting and the feedback signal indicating the degree of valve opening degree of the motorized valve.
The step of estimating the state is
A step of calculating the amount of change in the valve opening degree of the electric valve according to one command signal intermittently output by the step of intermittently outputting, and a step of calculating the amount of change in the valve opening degree of the electric valve.
The electric valve was substantially operated by acquiring the length of time during which the output of the command signal for one time was continued and by subtracting a predetermined dead time from the length of time during which the output was continued. The step to calculate the effective time, which is the time, and
Based on the change amount of the reference change pattern calculated based on the change amount of the valve opening degree of the electric valve, the change amount corresponding to the command signal for the one time of the reference change pattern, and the effective time. A step of determining whether or not the electric valve is in a predetermined abnormal state based on the degree of deviation per time .
The current position of the electric valve at the time when the command signal for one time is output, the current change direction of the electric valve indicated by the command signal for one time, and the electric valve indicated by the command signal for one time. A method of adjustment comprising a step of selecting a waste time to be used for calculating the effective time from a plurality of the waste times according to a change direction immediately before the above. An electric valve that receives the first command signal and operates in the open direction and also receives the second command signal and operates in the closed direction.
A regulator that controls a controlled object by using the electric valve as an operating element.
A command signal output unit that intermittently outputs either the first command signal or the second command signal so that the control amount acquired from the control target matches a preset target value.
A holding unit that holds a reference change pattern of the valve opening of the electric valve acquired by prior calibration, and a holding unit.
A state estimation unit for estimating the state of the electric valve based on a command signal output from the command signal output unit and a feedback signal indicating the degree of valve opening degree of the electric valve is provided.
The state estimation unit is
A change amount calculation unit that calculates the change amount of the valve opening degree of the electric valve according to one command signal intermittently output from the command signal output unit.
The electric valve was substantially operated by acquiring the length of time during which the output of the command signal for one time was continued and by subtracting a predetermined dead time from the length of time during which the output was continued. The effective time calculation unit that calculates the effective time, which is the time, and the effective time calculation unit
Based on the change amount of the reference change pattern calculated based on the change amount of the valve opening degree of the electric valve, the change amount corresponding to the command signal for the one time of the reference change pattern, and the effective time. based on the degree of deviation per time and, it viewed including the regulator and a determination unit that the electric valve to determine whether a predetermined abnormal condition,
The effective time calculation unit includes the current position of the electric valve at the time when the command signal for one time is output, the current change direction of the electric valve indicated by the command signal for one time, and the command for one time. An adjustment system that selects a dead time to be used for calculating the effective time from a plurality of the dead times according to a change direction immediately before the electric valve indicated by a signal.

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