JPS61199106A - Temperature regulator - Google Patents

Abstract

PURPOSE:To improve the responsiveness for temperature rise and to reduce the steady- state deviation and the variation by comparing the deviation of a controlled variable from a set value with a prescribed gain switching value and raising the gain if the deviation exceeds the switching value and setting the gain to a low value in the steady state. CONSTITUTION:At the operation start time, a set value (w) exceeds a controlled variable (y) of a controlled system 6, and a switching signal (s) of a gain switching part 9 is turned off because a difference (w)-(y) is larger than a gain switching value (e). Consequently, power is supplied from a power source 11 to both of heaters H1 and H2. At this time, a manipulated variable (u) is turned on because the difference between the controlled variable (y) and the set value (w) is large. Consequently, the controlled variable (y) approaches the set value (w) in a short time. When the difference (w)-(y) is smaller than the switching value (e), the signal (s) is outputted from the switching part 9, and only the heater H1 is selected. Thus, the rising speed of the controlled variable (y) is lower, and the controlled variable (y) coincides with the set value (w) approximately, and the manipulated variable (u) is controlled to be turned on and off interruptedly. Since the gain is low at this time, the controlled variable (y) has a level approximately equal to the set value (w) without being accompanied with the quick variation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to a temperature 11 mode device that performs switching control.

[Prior art and its problems]

When controlling the temperature of a controlled object, the step response is the fourth
As shown in the figure, in a non-oscillatory system, it is approximated by a transfer function of a first-order or higher-order delay element. Here, if the switching period of the manipulated variable of the temperature control device is low and the quantization is coarse, the fourth
As shown in range A in the figure, if the set value is set high, for example, 80% or more of the full range of control, the temperature fluctuation of the controlled object may increase or a steady-state deviation may occur. Furthermore, if the set value is set low, for example, 20% or less, as shown in range B in FIG. 4, with respect to the full range of control, a long cycle is required before the manipulated variable follows the set value. Therefore, it is preferable to set the gain of the manipulated variable, for example, the heater capacity in a heating system temperature control device, so that the set value is in an intermediate range of 20 to 80% of the full range of control. However, when changing the temperature set value to a higher value or at the time of startup after startup, it is preferable to shorten the time, and to speed up the response, it is preferable to lower the set value for the full range and increase the gain of the control amount. As described above, the optimum gain of the manipulated variable varies depending on the controlled variable, but there is a problem in that conventional temperature control devices cannot simultaneously satisfy such requirements.

[Purpose of the invention]

The present invention has been made in view of the problems of conventional temperature control devices, and the present invention provides control so that when increasing a set value, the response is accelerated to reach a predetermined set value in a short time. It is an object of the present invention to provide a temperature control device that can reduce fluctuations and steady-state deviations after reaching a steady state.

[Structure and Effects of the Invention] The present invention is a temperature adjustment device that controls a controlled object to a predetermined set value based on a temperature that is a controlled variable detected from the controlled object, and the temperature adjusting device The operating means has a gain of The invention is characterized in that it has a gain switching means for reducing the gain.

According to the present invention having such features, if the set value is changed to a higher temperature, or if the controlled variable of the controlled object is lower than the set value at the start of operation, the gain of the operating means is increased to control the controlled object. Since it is operated, the response is fast and it is possible to reach the set conditions in a short time. Furthermore, once a steady state is reached, the gain is low and the set value is switched to an intermediate value with respect to the full range of control, making it possible to reduce steady state deviations and fluctuations.

[Explanation of Examples]

FIG. 1 is a block diagram showing the configuration of the temperature control device according to the present invention.
is applied to the adjustment section 3 via.

The adjustment unit 3 is an automatic control unit that performs, for example, PID control on a controlled object, and is connected to a secondary feedback element 4.

The amount of operation is then given to the operation section 5. The operating section 5 changes the gain according to an input from the outside, for example, and includes heating means such as a heater to heat the controlled object 6. A detection unit 7 consisting of a temperature sensor that detects temperature as a controlled variable is connected to the controlled object 6, and the controlled variable y of the controlled object 60 is added to the addition point 1.

Now, in the present invention, the deviation, which is the difference between the control amount at the summing point 1 and the set value, is given to the summing point 8. The summing point 8 is further provided with a switching value e that determines the deviation for switching the gain of the operating section. The gain switching section 9 provides the operating section 5 with a gain switching signal S that turns on when the difference w - y between the set value W and the control amount y is smaller than the switching value e. Operation unit 5
switches the gain for operating the controlled object 6 based on this switching signal S.

Now, FIG. 2 is a block diagram showing an example in which the present invention is applied to a temperature control device using a heater. In this embodiment, a controlled object 6 is provided with heaters H1 and H2 as operating means 5. Heaters H1 and l-12 are connected in series to a power source 11 via a switch 10. The switch 10 is an operation switch that opens and closes the power supply 11, and is controlled on and off by the operation amount U of the adjustment section 3 of the temperature adjustment device shown in FIG. Also, switch 12 is electric! 11 is a changeover switch for switching the operating means 5 connected to the operating gain to 1, that is, the serial connection of heaters H1 and H2, and the gain to 2, that is, only the heater H1, the gain switching unit of the temperature control device described above. It is controlled by the switching signal S of 9. Note that the heaters H1 and H2 may have different capacities and may be selected by the switch 10.

(Operation of this embodiment) Next, the operation of this embodiment will be explained with reference to the time chart shown in FIG. At the time to when the operation is started, the set value W exceeds the control amount y of the controlled object 6, and the difference w-y is larger than the gain switching value e, so the switching signal S of the gain switching section 9 changes as shown in Fig. 3 (bl). It is turned off as shown. Therefore, the gain is 1, that is, both heaters H1 and H2 are energized by the power supply 11. At this time, since the difference between the control amount y and the set value W is large, the temperature adjustment device controls the operation amount U. is turned on as shown in FIG. 3(C). Therefore, as shown in FIG. 3(a), the control amount y approaches the set value W in a short time.Then, at time L1, the control amount y approaches the set value W. The difference w-y from the control amount y is the switching value e
If the value is below, the gain switching unit 9 outputs a gain switching signal S, and the switch 12 sets the gain to 2, that is, the heater H
Only 1 is selected. Therefore, the rising speed of the control amount y is the third
As shown in Figure (a), at time t2 it almost matches the set value W, and the manipulated variable U is intermittently controlled on and off. Since the gain of 2 at this time is low, the control amount y does not undergo rapid fluctuations and remains at a level equal to the set value W.

Now, when the set value W is changed at time t4, the deviation w - y from the control amount y becomes large again, the gain switching signal S is turned off, and the gain is switched to 1.

Therefore, the new set value is followed in a short time, and at time t5 when the deviation Wy becomes equal to or less than the switching value e, the gain switching signal is turned on again and the gain is switched to 2.

Then, at time t6, a transition is made to a steady state in which the manipulated variable U is intermittently switched. As described above, in the present invention, the gain of the operating section 5 is switched based on the deviation to improve responsiveness and stability in a steady state.

Although the present invention describes a temperature control device that controls the temperature of a controlled object using a manipulated variable having two gains, it is also possible to switch between a plurality of, for example, three levels of gain based on a deviation value.

Further, in this embodiment, a temperature control device having a heater as the operating section has been described, but the operating section is used as a cooling means and the gain of the operating section is determined depending on whether the difference y - w between the set value and the control amount exceeds the switching value. It is also conceivable to switch.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an example of a temperature control device according to the present invention, Fig. 2 is a block diagram showing an example of applying the present invention to a temperature control device using a heater, and Fig. 3 is a block diagram showing each part thereof. FIG. 4 is a time chart showing the temporal change of , and FIG. 4 is a diagram showing the step response of the controlled object. 1.2.8.--Addition point 3-.-1--Adjustment section 4-111111 Secondary feedback element
≦−−−−−−−Operation unit 6−・−−−−1 Control target
? --------1 detection part 9...-1--gain switching part 10, 12-- switch 11-1-- power supply Hl, H2--71ta patent applicant Tateishi Representative of Denki Co., Ltd. Patent attorney Yoshiki Okamoto (and 1 other person) Figure 1 W・-Setting value y・・・＠Goryu U・・−・−・Kusaku Higashi e---・・Switching value S----Y-in switching signal Fig. 2 Fig. 4 U Time Fig. 3

Claims (2)

[Claims] (1) A temperature adjustment device that controls a controlled object to a predetermined set value based on a temperature that is a controlled variable detected from the controlled object, and an operating means having a plurality of gains for operating the controlled object. and gain switching that compares the deviation between the control amount and the set value with a predetermined gain switching value, sets the operating means to a high gain when the deviation exceeds the switching value, and lowers the gain of the operating means in a steady state. A temperature regulating device comprising: means. (2) The operating means is an operating means having two heaters, and the gain switching means selects both heaters of the operating means when the set value exceeds the control amount and the deviation thereof exceeds the gain switching value. 2. The temperature control device according to claim 1, wherein one of the heaters is selected in a steady state.