TW201918824A - Temperature control device and control method thereof - Google Patents

Abstract

A temperature control device comprises a fan, a temperature sensor, a modeling unit and a proportional-integral-derivative (PID) controller. The PID controller is connected to the fan, the temperature sensor and the modeling unit. The fan is configured to control the temperature of a controlled area by airflow. The temperature sensor obtains a detected temperature and is disposed at the controlled area. The detected temperature indicates the temperature of the controlled area. The modeling unit calculates at least one cooling parameter group based on a transfer function. The PID controller controls the fan based on a second parameter group when the detected temperature is lower than a first temperature, and the PID controller controls the fan based on said at least one cooling parameter group when the detected temperature is higher than the first temperature. The second parameter comprising a plurality of second parameters and the plurality of second parameters is equal to a predetermined value.

Description

Temperature control device and control method thereof

The present invention relates to a temperature control device, and more particularly to a temperature control device having a proportional integral derivative controller.

In the field of servers, conventional temperature control devices often cause excessive cooling of the system due to temperature sensing and time difference of fan speed regulation, and at the same time cause excessive power consumption of the fan. In order to reduce power consumption, today's temperature control devices incorporate feedback control techniques, with Proportional-integral-derivative (PID) control being the most common.

The effect of PID control fan is mainly due to the design of control parameters. The current control parameter design is through repetitive setting, experimental verification and adjustment, that is, through Trial and error to obtain the parameter combination. It takes a lot of manpower and time, and the combination of parameters tested is usually not the best value. In addition, today's PID control fans set control parameters within the PID controller with only a fixed set of parameters. When the control parameter setting value is large, in the transient response interval (ie, during the period when the temperature starts to rise), the fan speed will rise sharply due to the detection of a sudden temperature difference, causing excessive cooling; and when the control parameter is set When the value is small, although the response of the fan speed in the transient response interval can be slowed down, the tracking effect of the transient response is not good, and it is difficult to quickly enter the steady-state response interval, so that it is easy to have a temperature before entering the steady-state response region. Overshoot situation. In addition, the fixed control parameters are also likely to cause Oscillation of the fan speed in the steady-state response interval.

Therefore, the control parameters in the PID controller are only set by a fixed set of parameters, and the requirements of the transient response interval and the steady-state response interval cannot be satisfied at the same time.

In view of the above, the present invention provides a temperature control device and a control method thereof to meet the above needs.

A temperature control apparatus according to an embodiment of the invention includes a fan, a temperature sensor, a modeling operation unit, and a proportional-integral-derivative controller, wherein the proportional-integral-derivative controller is coupled to the fan, the temperature sensor, and the modeling operation unit. The fan is used to drive the airflow to control the temperature of the controlled zone. The temperature sensor is used to obtain the detected temperature and is used to set the controlled area, and the detected temperature is used to indicate the temperature of the controlled area. The modeling operation unit calculates at least one cooling parameter combination according to the transfer function. The proportional integral derivative controller controls the fan according to the initial parameter combination when the detected temperature is lower than the first temperature, wherein the initial parameter combination includes a plurality of initial parameters, and the initial parameters are equal to a preset value. The proportional integral derivative controller controls the fan according to the at least one temperature drop parameter combination when the detected temperature is greater than or equal to the second temperature.

A control method according to an embodiment of the present invention is applicable to a temperature control device including a proportional integral derivative controller and a fan, wherein the temperature control device is configured to control the temperature of the controlled zone, and the rotational speed control method includes: according to a transfer function Calculating at least one combination of cooling parameters; obtaining a detected temperature, wherein the detected temperature is used to indicate the temperature of the controlled zone; when the detected temperature is less than the first temperature, setting a plurality of control parameters of the proportional integral derivative controller is Combining initial parameters to control the rotational speed of the fan, wherein the initial parameter combination includes a plurality of initial parameters that are the same as the number of the control parameters, and the initial parameters are equal to a preset value; and when the detected temperature is greater than or equal to the first At the time of temperature, the control parameters of the proportional integral derivative controller are set according to the at least one temperature drop parameter combination to control the rotational speed of the fan.

With the above structure, the temperature control device and the control method thereof disclosed in the present invention can set the control parameters of the Proportional-integral-derivative (PID) controller with different parameter combinations in different temperature intervals, and can avoid the transient state. In the response interval, the fan speed rises sharply due to the temperature difference and the control parameter multiplication, which leads to overcooling, avoids the ambient temperature overshoot before entering the steady state response region, and reduces the steady state response interval. The fan speed is oscillating.

The above description of the disclosure and the following description of the embodiments of the present invention are intended to illustrate and explain the spirit and principles of the invention, and to provide further explanation of the scope of the invention.

The detailed features and advantages of the present invention are set forth in the Detailed Description of the Detailed Description of the <RTIgt; </ RTI> <RTIgt; </ RTI> </ RTI> </ RTI> <RTIgt; The objects and advantages associated with the present invention can be readily understood by those skilled in the art. The following examples are intended to describe the present invention in further detail, but are not intended to limit the scope of the invention.

The invention provides a temperature control device for controlling the temperature of a controlled zone to be close to a rated temperature, wherein the controlled zone can be a space or an electronic component, and the rated temperature can be an electron in the controlled zone The component or the electronic component that is the controlled zone has an optimum operating temperature.

Please refer to FIG. 1. FIG. 1 is a functional block diagram of a temperature control apparatus according to an embodiment of the invention. As shown in FIG. 1, the temperature control device 1 includes a fan 11, a temperature sensor 13, a modeling operation unit 15, and a Proportional-integral-derivative (PID) controller 17, wherein the PID controller 17 is electrically connected. The fan 11, the temperature sensor 13, and the modeling operation unit 15 are provided.

Fan 11 is used to drive the airflow to control the temperature of the controlled zone. The temperature sensor 13 is, for example, a thermocouple, a thermistor, a resistance temperature detector (RTD), or an integrated circuit (IC) temperature sensor. The temperature sensor 13 is configured to obtain the detected temperature and is set in the controlled area, wherein the detected temperature can be used to indicate the temperature of the controlled area, that is, the detected temperature can be a space temperature or a temperature of a specific electronic component. .

The modeling operation unit 15 is, for example, a chip or a microcontroller, and establishes a transfer function as an approximate model according to the characteristics of the controlled region, and then calculates at least one cooling parameter combination according to the transfer function, wherein the transfer function is, for example, a first-order system. Add the First order plus time delay (FOPTD) function. In an embodiment, the modeling operation unit 15 calculates the first parameter combination according to the transfer function as the at least one cooling parameter combination. In an embodiment, the modeling operation unit 15 calculates the first parameter combination. The second parameter combination is further calculated according to the first parameter combination and the preset ratio, and the first parameter combination and the second parameter combination are used as the foregoing at least one cooling parameter combination.

The PID controller 17 is, for example, an Advanced RISC Machine (ARM) chip that generates a drive signal based on a plurality of control parameters to control the rotational speed of the fan 11. When the detected temperature is lower than the first temperature, the PID controller 17 controls the fan 11 according to the initial parameter combination, that is, when the detected temperature is lower than the first temperature, the PID controller 17 sets the control parameter. For the initial parameter combination; when the detected temperature is greater than or equal to the first temperature, the PID controller 17 controls the fan 11 according to the first parameter combination calculated by the modeling operation unit 15, that is, the control parameter is set to the first A combination of parameters. In addition, in another embodiment, when the modeling operation unit 15 can provide the second parameter combination and the detected temperature is greater than the second temperature, the PID controller 17 sets the control parameter to the second parameter combination. Wherein the second temperature is greater than the first temperature described above.

In the above embodiment, the first temperature and the second temperature are both lower than the rated temperature, and the temperature control device 1 controls the fan speed by using different control parameters in the plurality of temperature intervals separated by the first temperature and the second temperature. . The control method and operation of the temperature control device will be further described below. Please refer to FIG. 1 and FIG. 2 together. FIG. 2 is a flow chart of a method for controlling the rotational speed according to an embodiment of the invention.

In step S21, the modeling operation unit 15 of the temperature control device 1 calculates a set of cooling parameter combinations, that is, the first parameter combination, according to the transfer function. The first parameter combination includes a plurality of first parameters that are the same as the number of control parameters of the PID controller 17. As described above, the PID controller 17 generates a driving signal for controlling the fan according to a plurality of control parameters, and the control parameters include a proportional parameter, an integral parameter, and a differential parameter. That is to say, the plurality of first parameters included in the first parameter combination respectively correspond to the proportional parameter, the integral parameter, and the differential parameter.

In the present embodiment, the transfer function used by the modeling operation unit 15 is the aforementioned first-order system plus time delay (FOPTD), which constitutes an approximate model of the controlled region. The mathematical expression of this transfer function is as follows:

among them , and The system gain, time delay and time constant are respectively obtained by system identification, and then according to Ziegler-Nichols (Ziegler) The -Nichols, ZN) method calculates a first parameter combination comprising a first parameter corresponding to a proportional parameter, an integral parameter, and a differential parameter. In this way, by the calculation of the modeling operation unit 15, it is not necessary to use Trial and error, and the parameter combination is obtained through repetitive setting, experimental verification and adjustment, thereby reducing the cost of labor and time.

Next, in steps S22-S23, the temperature sensor 13 obtains the detected temperature and provides it to the PID controller 17, and the PID controller 17 determines whether the detected temperature is less than the first temperature, wherein the first temperature can be a PID controller. The default value in 17. In step S24, when the detected temperature is less than the first temperature, the PID controller 17 sets its control parameter to an initial parameter combination, wherein the initial parameter combination also includes a plurality of initial parameters that are the same as the number of control parameters, that is, The plurality of initial parameters correspond to a proportional parameter, an integral parameter, and a differential parameter, respectively. Moreover, these initial parameters are all equal to a predetermined value, such as zero.

In fact, the first temperature may be 0.63 times the rated temperature. When the detected temperature is lower than the first temperature, it indicates that the ambient temperature or a temperature difference between the component temperature and the rated temperature is relatively large, and the PID controller 17 will Set the value whose control parameter is zero or close to zero (ie, the initial parameter combination), so that in the conventional PID control method, the fan can be quickly pulled due to the large temperature difference and the control parameter multiplication. And then consume unnecessary power.

When the ambient temperature or the component temperature exceeds or equals the first temperature, as shown in step S25, the PID controller 17 sets the control parameter to the first parameter combination calculated by the modeling operation unit 15 to generate the driving signal. To control the fan 11.

The above embodiment is a two-stage control method, and in another embodiment, the control method of the temperature sensing device 1 can be further divided into three stages, please refer to FIG. 1 and FIG. 3 together, wherein FIG. 3 is based on this implementation. A flow chart of the speed control method illustrated by the example.

In the steps S31-S32, the modeling operation unit 15 of the temperature control device 1 calculates the first parameter combination according to the transfer function, and then calculates the second parameter combination according to the first parameter combination and a preset ratio, and is first. The combination of parameters and the combination of the second parameters are used as a combination of cooling parameters. The manner in which the first parameter combination is calculated by the transfer function is the same as the embodiment shown in FIG. 2 above, and therefore will not be described again. For the second parameter combination, further, the modeling operation unit 15 multiplies the first parameter in the first parameter combination by a preset ratio to obtain a plurality of second parameters, and the second parameter constitutes a Two parameter combination. In other words, the second parameter combination includes a plurality of second parameters, and the second parameters also correspond to the proportional parameter, the integral parameter, and the differential parameter, respectively. In this embodiment, the value of less than 1 (for example, 1/2) is used as the preset ratio, that is, the second parameter is smaller than the first parameter.

In steps S33-S35, the temperature sensor 13 obtains the detected temperature and provides it to the PID controller 17, and the PID controller 17 then determines whether the detected temperature is less than the first temperature. When the detected temperature is less than the first temperature, the PID The controller 17 sets its control parameters to the initial parameter combinations. In this embodiment, steps S33-S35 are the same as steps S22-S24 in the embodiment shown in FIG. 2, and the PID controller 17 has a considerable temperature difference between the ambient temperature or the component temperature and the rated temperature. , the control parameter will be set to zero or close to zero value to avoid excessive fan speed increase.

Next, in step S36, when the PID controller 17 determines that the detected temperature is greater than or equal to the first temperature, it is determined whether the detected temperature is less than the second temperature. The second temperature is a preset value in the PID controller 17, for example, 97% of the rated temperature. When the detected temperature is greater than or equal to the first temperature but less than the second temperature, it indicates that there is still a temperature difference between the detected temperature and the rated temperature. At this time, the PID controller 17 sets the control parameter with the first parameter combination, such as Step S37 is shown. When the detected temperature is greater than or equal to the second temperature, it indicates that the detected temperature is close to the rated temperature, and the PID controller 17 sets the control parameter to control the fan speed by the second parameter combination, as shown in step S38.

For continuous control, please refer to FIG. 4. FIG. 4 is a time-temperature diagram of the rotational speed control method according to the embodiment. As shown in FIG. 4, the control method of the temperature control device can be divided into three stages I, II and III. When the detected temperature is in the phase I, that is, the detected temperature is lower than the first temperature T1, the PID controller 17 can set the control parameter to zero. Since the temperature of the controlled zone in this stage is much lower than the target (ie, the rated temperature), it is not necessary to drive the fan to cool down, thereby achieving the purpose of energy saving, and thus avoiding excessive cooling caused by excessively increasing fan speed. Then, when the detected temperature reaches the phase II, that is, when the detected temperature is between the first temperature T1 and the second temperature T2, the PID controller 17 sets the control parameter to the first parameter combination to avoid the control parameter being too small. This causes an overshoot of the ambient temperature or component temperature. When the detected temperature reaches the phase III, that is, when the detected temperature is greater than the second temperature T2 and is close to the rated temperature Tn, the PID controller 17 sets the control parameter to a second parameter combination whose value is smaller than the first parameter combination to reduce The rate of change of the fan speed, which in turn reduces the Oscillation of the fan speed.

With the above structure, the temperature control device and the control method thereof disclosed in the present invention can set the control parameters of the Proportional-Integral-Derivative (PID) controller with different parameter combinations in different temperature intervals, and can avoid the transient state. In the response interval, the fan speed rises sharply due to the temperature difference and the control parameter multiplication, which leads to over-cooling. It can also avoid the ambient temperature or component temperature overshoot before entering the steady-state response region, and reduce the steady state. The oscillation of the fan speed in the response interval.

Although the present invention has been disclosed above in the foregoing embodiments, it is not intended to limit the invention. It is within the scope of the invention to be modified and modified without departing from the spirit and scope of the invention. Please refer to the attached patent application for the scope of protection defined by the present invention.

1‧‧‧temperature control device

11‧‧‧Fan

13‧‧‧Temperature Sensor

15‧‧‧Modeling unit

17‧‧‧Proportional Integral Derivative Controller

Phases I, II, III‧‧

T1‧‧‧ first temperature

T2‧‧‧second temperature

Tn‧‧‧ rated temperature

1 is a functional block diagram of a temperature control device according to an embodiment of the invention. 2 is a flow chart of a method of controlling a rotational speed according to an embodiment of the invention. FIG. 3 is a flow chart of a method for controlling a rotational speed according to another embodiment of the present invention. 4 is a time-temperature diagram of a rotational speed control method according to an embodiment of the invention.

Claims (10)

A temperature control device includes: a fan for driving a gas flow to control a temperature of a controlled zone; and a temperature sensor for obtaining a detected temperature, wherein the temperature sensor is configured to be disposed in the controlled zone And the detecting temperature is used to represent the temperature of the controlled area; a modeling operation unit calculates at least one cooling parameter combination according to a transfer function; and a proportional integral derivative controller connected to the fan, the a temperature sensor and the modeling operation unit, the proportional integral derivative controller controls the fan according to an initial parameter combination when the detection temperature is less than a first temperature, and the detection temperature is greater than or equal to the first At the time of temperature, the proportional integral derivative controller controls the fan according to the at least one temperature drop parameter combination; wherein the initial parameter combination includes a plurality of initial parameters, and the initial parameters are equal to a preset value. The temperature control device of claim 1, configured to control an ambient temperature or a component temperature below a nominal temperature, the temperature sensor obtaining the detected temperature according to the ambient temperature or the component temperature, and the first The temperature is less than the rated temperature. The temperature control device of claim 1, wherein the preset value is zero. The temperature control device of claim 1, wherein the at least one cooling parameter calculated by the modeling operation unit is combined into a first parameter combination, and when the detection temperature is greater than or equal to the first temperature, the ratio is The integral derivative controller controls the fan according to the first parameter combination. The temperature control device of claim 1, wherein the at least one cooling parameter calculated by the modeling operation unit is combined into a first parameter combination and a second parameter combination, wherein the modeling operation unit is based on the first parameter Combining with a preset ratio to obtain the second parameter combination, when the detected temperature is greater than or equal to the first temperature but less than a second temperature, the proportional integral derivative controller controls the fan according to the first parameter combination, When the detected temperature is greater than or equal to the second temperature, the proportional integral derivative controller controls the fan according to the second parameter combination, wherein the second temperature is greater than the first temperature. A control method is applicable to a temperature control device including a proportional integral derivative controller and a fan, wherein the temperature control device is configured to control a temperature of a controlled zone, and the rotational speed control method comprises: calculating according to a transfer function Combining at least one cooling parameter; obtaining a detecting temperature, wherein the detecting temperature is used to indicate the temperature of the controlled zone; and when the detecting temperature is less than a first temperature, setting the proportional integral derivative controller The control parameter is an initial parameter combination to control the rotational speed of the fan, wherein the initial parameter combination includes a plurality of initial parameters that are the same as the number of the control parameters, and the initial parameters are equal to a preset value; When the detected temperature is greater than or equal to the first temperature, the control parameters of the proportional integral derivative controller are set according to the at least one temperature drop parameter combination to control the rotational speed of the fan. The control method of claim 6, wherein the temperature control device is configured to control an ambient temperature or a component temperature below a nominal temperature, the detected temperature is related to the ambient temperature or the component temperature, and the first The temperature is less than the rated temperature. The control method of claim 6, wherein the preset value is zero. The control method of claim 6, wherein the at least one cooling parameter combination is a first parameter combination, and when the detection temperature is greater than or equal to the first temperature, setting the proportional integral according to the at least one cooling parameter combination The controlling parameters of the differential controller to control the rotational speed of the fan include: setting a plurality of control parameters of the proportional integral derivative controller to the first parameter combination. The control method of claim 6, the calculating, according to a transfer function, the at least one cooling parameter combination comprises: calculating a first parameter combination according to a transfer function; and calculating a first ratio according to the first parameter combination and a preset ratio a second parameter combination; and when the detection temperature is greater than or equal to the first temperature, setting the control parameters of the proportional integral derivative controller according to the at least one temperature reduction parameter combination to control the rotation speed of the fan comprises: when When the detection temperature is less than a second temperature, the proportional integral derivative controller is set to control the rotation speed of the fan by the first parameter combination; and when the detection temperature is greater than or equal to the second temperature, the second The parameter combination sets the proportional integral derivative controller to control the rotational speed of the fan; wherein the second temperature is greater than the first temperature.