JPS5842881B2 - Pulse width output controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pulse width output controller implemented by a computer program.

A pulse width signal is given as a speed-type operation signal to a process operating device such as an electric valve that performs an integral operation.

A pulse width output controller is used to obtain such an operating signal.

To increase flexibility in process control, it is desirable that the pulse width output controller have manual adjustment capabilities similar to positional output controllers.

In that case, in order to make accurate manual adjustments, an indicator is required to indicate the amount of output set by the operator, and an indicator is also required to indicate the amount of actuation of the process operator.

If you try to implement such a pulse width output controller using existing hardware, you can combine a pulse width output converter with the output end of the differential output controller, and use the differential output controller to determine the process amount to be controlled and its value. A differential output signal corresponding to the deviation from the set value is obtained, which is converted into a pulse width output signal by a pulse width output converter and output to the process controller.

The amount of actuation of the process operator is fed back to the pulse width output converter and indicated by an indicator.

For manual adjustment, a manual setter can be connected to the pulse width output converter by switching, and during manual adjustment, a set value corresponding to a differential output signal is given from the manual setter.

In this way, the process quantity is indicated by the input indicator of the differential output controller, the manual output quantity set by the operator is indicated by the scale of the manual setting instrument, and the operating quantity of the process controller is indicated by the pulse width output converter. Indicated by input indicator.

When an operator performs manual adjustment on such equipment, it is necessary to refer to the current value of the process variable and the current value of the actuation amount of the process controller, and to check the output amount on the scale of the manual setting device. be.

However, the current value of the process variable is indicated by the input indicator of the differential output controller, the current value of the operating variable of the process controller is indicated by the input indicator of the pulse width output controller, and the output quantity of manual adjustment is Since it is indicated by the scale of the manual setting device, all indicated values are indicated by separate indicators or indicators.

For this reason, it is inconvenient to refer to each instruction value, and it is troublesome that the output amount of the manual setting device must be reset each time it is transferred to the pulse width output converter.

On the other hand, there are new types of controllers in which the required functions are realized by computer programs, and the display and operability are equivalent to those of conventional analog controllers.

This type of controller can achieve a variety of functions depending on the program, so if you also use this type of pulse width output controller,
There is a possibility that something useful for practical purposes can be obtained.

An object of the present invention is to provide a pulse width output controller that uses a computer program and has good display and operability.

The controller of the present invention displays the process amount and the actuation amount of the process operating device in analog form using one composite indicator, and during manual adjustment, the output amount can be set by simply moving the pointer that indicates the actuation amount of the process operating device. I have a program that allows me to do this.

The present invention will be explained below with reference to the drawings.

FIG. 1 is a conceptual configuration diagram of a process control device to which the present invention is applied.

In FIG. 1, 1 is a computer control device, 2 is an operator operating device, and 3 is a process to be controlled.

The computer control device 1 includes a computer and various interfaces, and sends and receives signals to and from the process 3 to be controlled through the instrumentation wiring 4.

The operator operating device 2 is connected to a computer by a data transmission line wired under the floor, and communication between the operator and the computer can be performed through a color CRT 21 and keyboards 22 and 23.

An example of the screen drawn on the CRT 21 is shown in FIG.

These screens display the status of each point of the controlled object by simulating an analog indicator, each scale band being one indicator, and measured values are shown in bar graphs.

One screen displays the status of eight kansho.

These eight indicators indicate measurements that are related to each other.

The symbol below each indicator is the tag number.

8 indicators family tag number F401. L402,
The L4.10 indicator is a composite indicator that simulates the indicator of an analog controller, and the input signal (
The triangular pointer (set value pointer) on the right side indicates the set value SV, and the triangular pointer (output pointer) on the left side indicates the adjustment output signal Mv.

The numbers attached to the scale band are numerical values for reading the input signal P■ and the set value S■.

When reading the value of the output signal MV, change this scale band from 0 to 1.
Regard it as the 00% scale, and read the position of the output pointer relative to it.

The other indicators are simply measurement value indicators, and indicate the measurement value P■ with a bar graph.

The fact that the bar graph does not appear indicates that the measured value is zero or the lowest scale value.

The reading on the indicator is also displayed numerically.

The numbers and their engineering units are displayed in the space above each indicator.

The display order is from top to bottom: engineering unit, input signal PV, set value SV.
, the output signal Mv(2).

These allow the values of each signal to be known precisely.

The output signal MvO value changes automatically according to calculations by a computer, but can also be changed manually by an operator using a keyboard.

Switching between automatic mode and manual mode and output signal MY
The setting value SV can be operated for each individual controller using the keyboard 22 provided below the CRT screen and paired with the indicator.

This is shown in FIG. 3 for one controller.

The key 221 switches between automatic mode and manual mode each time it is pressed.

When the key 222 is pressed, the operation value increases continuously,
When the key 222' is pressed, the operation value decreases continuously.

In the automatic mode, the set value pointer is a conspicuous color (for example, red) and the output pointer is a subdued color (for example, yellow), and when the key 222 or 222' is pressed in this state, the set value Sv changes. The setting value pointer moves.

When the set value SV changes, the output changes and the output pointer moves as the computer calculates accordingly.

When switching to manual mode, the color of the setpoint pointer and the output pointer alternate, with the setpoint pointer becoming a subdued color and the output pointer becoming a conspicuous color.

When key 222 or 222' is pressed in this state, output M
V changes and the output pointer moves.

Other cascade control modes, backup modes,
When the input is open, calibration is in progress, or the host computer is in a setting mode, both the set value pointer and the output pointer turn to a subdued color, and the key 222
, 222' cannot be operated.

In other words, each time the control mode is switched between automatic mode and manual mode, the set value pointer and output pointer change colors to indicate that the control mode has been switched, and the signals that can be operated by the operator are shown in a prominent color. .

If the setting value pointer is colored conspicuously, it is in automatic mode, and if it is the output pointer, it is in manual mode.

If both are muted colors, this indicates that the operator cannot operate either the set value pointer or the output pointer.

This makes it easy to recognize the currently active control mode and the operable signals.

When configuring a pulse width output controller according to this format, the procedure is as follows.

FIG. 4 conceptually shows an example of a control loop using the pulse width output controller of the present invention.

In FIG. 4, 301 is a process amount detector, 302
is an electric valve, 10L101' is an input converter, 102 is a status converter, 103.103' is a relay 104,1
04' is an input register, 105 is a status register, and 106 and 106' are UIJ level drive circuits.

The signal from the detector 301 is converted by the input converter 101 and held in the input register 104 as a digital signal.

The operating amount of the electric valve 302 is converted by the input converter 101' and is held as a digital signal in the input register 104'.

The status signal of the electric valve 302 is converted by the status converter 102 and held in the status register 105 as a digital signal.

This status signal indicates whether the electric valve is in a field operated state (local) or a computer operated state (remote).

Input operations to each register are performed periodically, and the latest data is held.

The relays 103 and 103' operate the electric valve 302 in opposite directions, and each relay drive circuit 1
06, 106' output signal.

Although the above is a part composed of hardware, each block described below is realized by a computer program.

107 is a linearization block, 108 is a temperature and pressure correction block,
109 is a filter block, 110 is a feedback control block, 111 is an internal unified signalization block, 1
12 is an output vine block, 113 is an output processing block, and 114 and 115 are switch blocks.

211 is a composite indicator drawn on the CRT mentioned above, 222.
The 222' button and 221 are the aforementioned keys.

The data representing the process amount held in the input register 104 is subjected to linearization, temperature and pressure correction, button and filtering operations through blocks 107, 108, and 109, respectively, and is sent to the feedback control block 110 and the composite indicator 211. Given.

The process amount is assumed to be 1 flow rate.

The process amount is indicated by a bar graph of the composite indicator 211.

Feedback control block 110 produces a differential output signal responsive to the deviation between the process variable and the set point.

The set value is indicated by the set value pointer of the composite indicator 211.

The operating amount of the electric valve 302 held in the input register 104' is converted into a unified signal by an internal unified signal block 111 (
0 to 100%), is given to the compound indicator 211, and is indicated by the output pointer.

The differential output signal of feedback control block 110 is provided to the AUT (auto) side of switch block 114 through output limiter block 112.

The MAN side of switch block 114 is provided with a manual output signal produced by actuation of keys 222 and 222'.

The switching operation of switch block 114 is commanded by key 221.

The output processing block 113 determines the pulse width value corresponding to the signal applied through the switch block 114 and outputs this value to the relay drive circuit 1 through the switch block 115.
Set to 06 or 106'.

Which one to set depends on the operating direction of the electric valve 302.

The switching action of the switch block 115 is defined by the contents of the status register 105, with the contacts closed when it indicates ``remote'' and the contacts opened when it indicates ``local.''

The output of the manual adjustment output processing block 113 is added to the output of the internal unified signal conversion block and is applied to the composite indicator 211.

Of such a block configuration, the portion surrounded by a dashed line is a characteristic portion of the present invention, and a detailed functional block diagram thereof is shown in FIG.

In FIG. 8, 401 is a storage block, 402 is a storage value write block, 403 is a storage value increase/decrease block,
404 is a memory value read block, 405 is a subtraction block, 406 is an output limiter block, 407 is a coincidence detection block, 408 is an addition block, 409 is a direction determination block, 410 is a compensation block, 411 is a prohibition block, 412 is a hahalus width Output locks 413-414 are switch blocks.

The memory block 401 has two memory cells, one for storing the current MV and the other for storing the previous MV.
02 stores the output value of the internal unified signaling block 111 or the output value of the summing block 408 provided via the switch block 414.

The write block 402 is controlled by the output of the match detection block 407, which is provided via a switch block 413, to store the output of the internal unified signaling block in two storage cells when the match output is present, and to store the output of the internal unified signaling block in two storage cells, and to output the mismatch output. is output, the output of the addition block 408 is
v Store it in the memory cell.

Note that when the switch block 413 is open and the output of the coincidence detection block 407 is not given, the output of the internal unified signal conversion block 111 is stored in two cells.

The current MY storage value of the storage block 401 is increased or decreased at a constant rate by the increase/decrease block 403.

A command is given to the increase/decrease block 403 from the key 222 or 222' via a switch block 415, and the stored value is increased/decreased accordingly.

The read block 404 reads the current M of the storage block 401.
Read the V memory value and the previous MY memory value.

This time, the MV memory value is given to the composite indicator 211 and displayed in analog form with an output pointer.

The current MV storage value and the previous MV storage value are provided to a subtraction circuit 405, where the difference is determined.

This difference is provided to one contact MAN of switch block 114 through output limiter block 406.

The other contact AUT of switch flock 114 has
The output of the feedback control block 110 is provided through an output limiter block 112.

The current MY storage value and the previous MV storage value read by the read block 404 are also given to a coincidence detection block 407, and a coincidence between the two is detected.

Also, the previous MY memory value and the output limiter block 406
The output of is given to addition block 408, and the sum of both is calculated.

The output of the output limiter block 112 or the output of the output limiter block 406 selected by the switch block 114 is given to a direction determination block 409, and when the direction is the same as the previous one, the 11th output is output. In the case opposite to the previous time, backlash compensation etc. are performed by the compensation block 410 and the result is output.

This output is provided via inhibit block 411 to pulse width output block 412 where it is converted to a pulse width signal and output through switch block 115.

While the pulse width output block 412 is outputting a pulse width signal, the inhibition block 411 prohibits input for new pulse width conversion, and the write block 402
functions are now suspended.

Switch block 114. t, - and 413 to 415 are switched in conjunction with each other based on the operation of the key 221.

These keys are inserted into the contact AUT in automatic mode,
In manual mode, contact MAN is injected.

The operations of such functional blocks are shown in flow charts as shown in FIGS. 5 and 6.

FIG. 5 shows the case of automatic adjustment, and FIG. 6 shows the case of manual adjustment.

Note that in both figures, the feedback input is the operating amount of the electric valve 302 held in the input register 104'.

This is because the result of driving a process controller with a computer is fed back to the computer, so it is called as such.

The programs shown in both figures are activated periodically during automatic adjustment blackout and manual adjustment, respectively.

The operation in the case of automatic adjustment will be explained with reference to FIG.

Automatic adjustment is shown in switch block 1 in Figure 8.
14 and 413 to 415 are connected to the contacts AUT.

At step aK>, it is determined whether the status is "remote" or "local" based on the contents of the status register 105.

In the case of "local", it branches to the attack, and here the loop/
Open status.

This corresponds to opening switch block 115.

Then, in step d, the feedback input is stored in the current MV and previous MV.

The above operations are repeated periodically while "local" continues.

As a result, the current value of the actuation amount of the electric valve 302 is stored in the MV this time, so the output pointer of the composite indicator 211 indicates the current value of the actuation amount of the electric valve 302.

In the case of "remote", a branch is made from step a to step f, where the feedback input is stored in the current MV and previous MV.

Then, for step g, a limit is applied to the differential output signal provided from the feedback control block 110 if it exceeds the permissible limit.

Next, press the step button to activate the electric valve 30 according to the differential output signal.
It is checked whether the operating direction of 2 is the same as the previous one, and if it is the same, then step i is reached; if it is different, the differential output signal is subjected to backlash compensation processing at step j, and then step i is reached.

At attack i, the pulse width value corresponding to the differential output signal is output and exits to END.

As a result, the control output of the feedback control block 110 is set to the relay drive circuit 106 or 106' as a pulse width value.

The relay drive circuit 1064 and the relay 106' respectively drive the relay 103 or 103' according to the set value to operate the electric valve 302.

When key 221 is pressed in the automatic adjustment state, switch block 114 and 413 to 415 switch to contact MA in FIG.
N and switches to manual adjustment state.

In the case of manual adjustment, the following operations are performed according to the program shown in FIG.

1. First, press the button in step a, and it is judged whether it is "remote" or "local". If it is "local", branch to step 2, set the loop status to open, and then go to step d to input feedback. Save this time's MV and last time's MY, and exit to END.

Repeat the above procedure periodically while "local" continues.

This is no different from "local" during automatic adjustment.

If it is determined to be “remote” in step a, proceed to step e.
The process branches to and determines whether the previously output pulse width signal is continuing.

While the pulse width signal continues, it is meaningless to output the next pulse width signal, so the process exits to END.

If the pulse width signal is not continuing, the process branches to step f, and it is determined whether the contents of the previous MV and the current MV match.

If the keys 222 and 222' are pressed by the operator, the two do not match, and if the keys 222 and 222' are not pressed, the two match.

If there is a mismatch, the process branches to step g, where the manual output amount set by the operator is determined based on the difference between the contents of the current MV and the previous MY.
Pn is determined, and if it exceeds the allowable limit, a restriction is applied and the content of the previous MV is corrected by Δpn.

Then, the output direction is determined in each stage, and if the output direction is the same, the stage i is reached, and if it is the opposite, backlash compensation is applied at the stage j, and the stage i is reached.

At stage i, a pulse width value corresponding to the manual output amount is output, and the process exits to END.

As a result, the electric valve is operated according to the manual output amount.

That is, the operator points the output pointer of the composite indicator 211, which indicates the operating amount of the electric valve, to the keys 222, 222.
' When the valve is moved by a desired distance, a corresponding pulse width output signal is provided to the electric valve 302.

The duration of the pulse width output is determined so that the amount of operation of the process operator when operated accordingly matches the value set by the operator on the composite indicator.

When the operator does not give a manual output amount, since the contents of the current MY and the previous MV match in step f, the process branches to step m, where the feedback input is changed to the current MY.
It is memorized in the previous Mv and exits to END.

The above manual adjustment state is shown in FIG. 7 by the movement of the output pointer of the composite indicator 211.

When the operator presses the key 222, the composite indicator 2
The output pointer 11 is displaced upward at a uniform speed and stops when the operator releases the key 222 (Fig. 7a).
+b).

When a pulse width output signal corresponding to the amount of displacement of the output pointer during that time is given from the relay 103 to the motor-operated valve 302 (Fig. 7c), the motor-operated valve 302 operates accordingly and generates an operating amount (feedback value). changes (Figure 7a)
.

While the relay 103 is outputting the pulse width signal, the program immediately exits to END by processing step e in FIG. 6, so the feedback input is not stored in the MV this time.

Therefore, the contents of MY this time are 11 operated by the operator.
This value is displayed on the compound indicator 211, so the output pointer stops at the position given by the operator.
(Figure 7a).

Among them, the contents of the previous MY match the contents of the current MY due to the processing in step g described above.

When the pulse width output of the relay 103 is finished, the electric valve 30
The operating amount of No. 2 corresponds to the value set by the operator on the composite indicator.

Immediately after that, the program shown in FIG. 6 is activated, and in step f, the previous MV minus the current MV is determined, leading to step m, where the feedback input is stored in the current MV and previous MY.

From now on, the contents of the current MV will be the amount of operation of the electric valve 302, and the output pointer of the composite indicator will indicate the amount of operation of the electric valve 302.

The output pointer may move by the amount of error at the display switching point.

As described above, in the pulse width output controller of the present invention, when the operator manually changes the indicated value of the indicator indicating the operating amount of the process controller to a desired value, the amount of change is A corresponding pulse width output signal is provided to the process operator, and the process operator operates at the housing whose actuation amount reaches the manual set point.

Therefore, the operating amount indicator of the process controller becomes the same as the output indicator of the position type output adjustment needle from the operator's perspective, and when the desired operating amount is set on the scale, the actual operating amount will also be the same. There is little awareness of setting the manual output amount using differential values.

A manual output amount can be given without being aware of the operating speed of the process operating device, and there is no need to worry about resetting it.

In addition, the composite indicator displays the process amount, its setting value, the operating amount of the process operating device, and the manual output amount all at once.

From the above, the pulse width output controller of the present invention has good display and operability.

The button composite indicator is not limited to an image drawn on a CRT, but may be a computer-based indicator.

Further, the indicator that indicates the operating amount and manual output amount of the process operating device may be a separate unit as long as it is placed near the indicator that indicates the process amount and set value.

[Brief explanation of drawings]

FIG. 1 is a conceptual configuration diagram of a process control device to which the present invention is applied, FIGS. 2 and 3 are detailed diagrams of a part of FIG. 1,
Fig. 4 is an example of a control loop using the pulse width output controller of the present invention, and the fifth rotation and Fig. 6 are program flow diagrams.
7 is an explanatory diagram of the operation, and FIG. 8 is a functional block diagram of the characteristic parts of the present invention. DESCRIPTION OF SYMBOLS 1... Computer control device, 2... Operator operation device, 21... CRT, 22.23... Keyboard,
3... Process, 301... Process amount detector, 3
02...Process operator, 101, 101'-...Input converter, 102...Status converter, 103,1
03'...Relay 104,104'...Input register, 105...Status register, 106,1
06'...Relay drive circuit, 107...Linearization block, 108...Temperature and pressure correction block, 109...Filter block, 110...Feedback control block, 111...Internal unification Signaling block, 11
2... Output limiter block, 113... Output processing block, 114.115... Switch block, 211... Compound indicator, 22L 222, 222'
-...Key.

Claims (1)

[Claims] 1. It has display/operation means and automatic/manual mode switching means equivalent to an analog controller, and drives a process operating device that performs integral operation, and the manipulated variable is fed back from the process operating device. A computer control device comprising means for generating a differential output signal for process control based on a deviation between a process amount and a set value, a storage means for storing a pair of data, and a pair of said storage means when the manual mode is pressed. means for changing one of the data in accordance with the operation of the operating means; a reading means for reading the pair of data from the storage means and providing one of the data to the display means; a difference between the pair of data read by the reading means; means for determining the sum of the output of the means for determining the difference and the other of the pair of data read by the reading means; means for detecting coincidence of the pair of data read by the reading means; in automatic mode; , the operation amount of the process operating device is written in the storage means as a pair of data, and in manual mode, the operation amount is controlled by the output of the coincidence detection means,
- When a scattered output exists, the operation amount of the process operating device is written as a pair of data in the storage means, and when a mismatched output exists, the output of the means for calculating the sum is written as the other data in the storage means. In automatic and automatic modes, the output of the means for generating the difference output signal is selected, and in the manual mode, the output of the means for determining the difference is selected, and each is converted into a pulse width signal and sent to the process controller. A pulse width output regulator comprising means for providing.