TW201925969A - Temperature control device and method thereof - Google Patents

Abstract

A temperature control device comprises a fan, a temperature sensor, a parameter modulating unit and a proportional-integral-derivative (PID) controller. 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 parameter modulating unit calculates a temperature deviation value according to the detected temperature, an external environment value, a targeted temperature, and obtains a cooling parameter group according to the temperature deviation value. The PID controller controls the fan according to an initial parameter group which includes initial parameters with the same value when the temperature deviation value is larger than a judgment threshold, and controls the fan according to the cooling parameter group when the temperature deviation value is equal to or less than the judgment threshold.

Description

Temperature control device and 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, setting the control parameters in the PID controller with a fixed parameter combination cannot meet the requirements of the transient response interval and the steady-state response interval 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 device according to an embodiment of the invention includes a fan, a temperature sensor, a parameter adjustment unit, and a Proportional-integral-derivative (PID) controller. 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 value and is set in the controlled area, and the detected temperature value is used to indicate the temperature of the controlled area. The parameter adjustment unit calculates the temperature error value according to the detected temperature value, the external ambient temperature value and the target temperature value, and calculates the combination of the cooling parameter according to the temperature error value and the modulation equation. When the temperature error value is greater than the determination threshold, the PID controller controls the fan according to the initial parameter combination, and when the temperature error value is equal to or less than the determination threshold, the fan is controlled according to the combination of the cooling parameter. The initial parameter combination includes a plurality of initial parameters that are equal to preset values.

A temperature control method according to an embodiment of the present invention is applicable to a temperature control device including a PID controller and a fan, wherein the temperature control device is for controlling the temperature of the controlled zone. The speed control method includes: obtaining a detected temperature value, wherein the detected temperature value is used to represent the temperature of the controlled area; and calculating a temperature error value according to the detected temperature value, the external ambient temperature value, and the target temperature value; The temperature error value and the modulation equation are calculated to obtain a combination of cooling parameters; when the temperature error value is greater than the determination threshold, a plurality of control parameters of the PID controller are set as initial parameter combinations to control the fan, wherein the initial parameter combination includes the same number of control parameters. a plurality of initial parameters, wherein the initial parameters are equal to a preset value; and when the temperature error value is equal to or less than the determination threshold, the control parameters of the PID controller are set according to the combination of the cooling parameters to control the fan.

With the above structure, the temperature control device and the control method thereof disclosed in the present invention control the fan with the initial parameter combination when the controlled area is initially started, and according to the temperature error value and the modulation when the temperature error value is equal to or smaller than the determination threshold value. The equation dynamically adjusts the control parameters of the PID controller to prevent the fan speed from rising sharply due to the temperature difference and the addition of control parameters in the transient response interval, resulting in excessive cooling and avoiding entering the steady-state response region. The ambient temperature overshoot condition and the fluctuation of the fan speed in the steady state response range. In addition, the control method of automatically obtaining the PID control parameters through the temperature control device not only achieves optimal control, but also reduces the labor cost for the operator to perform parameter adjustment.

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.

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 parameter adjustment unit 15, and a Proportional-integral-derivative (PID) controller 17, wherein the PID controller 17 is electrically connected to The fan 11, the temperature sensor 13, and the parameter adjustment unit 15.

Fan 11 is used to drive the airflow to control the temperature of the controlled zone. In detail, the fan 11 of the temperature control device 1 is controlled to control the temperature of the controlled zone to approach the target temperature value, wherein the controlled zone may be a space or an electronic component, and the target temperature value may indicate the The electronic components in the controlled zone or the electronic components that are controlled zones have an optimum operating temperature.

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 a detected temperature value and is set in the controlled area, wherein the detected temperature value can be used to indicate the temperature of the controlled area, that is, the detected temperature value can represent a space temperature or a specific electron. The temperature of the component.

The parameter adjustment unit 15 is, for example, a chip or a microcontroller, and calculates a temperature error value according to the detected temperature value, the external ambient temperature value, and the target temperature value. The detected temperature value is measured by the temperature sensor 13 to measure the internal temperature of the controlled area, and the external ambient temperature value is measured, for example, by a second temperature sensor disposed outside the controlled area. Temperature value. For example, when the controlled zone is a server, the detected temperature value represents the ambient temperature inside the server, and the external ambient temperature value represents the temperature of the air inlet of the server. In another embodiment, the external ambient temperature value can also be set by the user in the parameter adjustment unit 15. The target temperature value, as previously described, indicates that the electronic component in the controlled zone or the electronic component that is the controlled zone has an optimum operating temperature. The target temperature value may be set by the parameter adjustment unit 15 from the controlled area, or set by the user. The parameter adjusting unit 15 calculates the temperature error value according to the above three temperature values, and then calculates the cooling parameter combination according to the temperature error value and the modulation equation, wherein the calculation method of the temperature error value and the details of the modulation equation will be Described later.

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 temperature error value is greater than the determination threshold, the PID controller 17 combines the initial parameters to control the fan 11, that is, when the temperature error value is greater than the determination threshold, the PID controller 17 sets the control parameter to the initial value. When the temperature error value is equal to or smaller than the determination threshold, the PID controller 17 controls the fan 11 according to the combination of the temperature reduction parameters calculated by the parameter adjustment unit 15, that is, the control parameter is set as the combination of the cooling parameters.

The temperature control method and operation of the temperature control device will be further described. Referring to FIG. 1 and FIG. 2 together, FIG. 2 is a flow chart of a temperature control method according to an embodiment of the invention.

In steps S21 to S22, the parameter adjustment unit 15 of the temperature control device 1 acquires the detected temperature value (ie, the internal ambient temperature value) of the controlled area from the temperature sensor 13, and according to the detected temperature value and the external ambient temperature. The value and the target temperature value are calculated to obtain a temperature error value. In detail, the parameter adjustment unit 15 normalizes the three temperature values, divides the difference between the target temperature value and the detected temperature value, and the difference between the target temperature value and the external ambient temperature value to obtain a temperature error. The value is as shown in the following formula:

,among them Temperature error value; Is the target temperature value; To detect the temperature value; For external ambient temperature values.

In step S23, the parameter adjusting unit 15 calculates a cooling parameter combination according to the temperature error value and the modulation equation, wherein the cooling parameter combination includes a plurality of cooling parameters respectively corresponding to the control parameters of the PID controller 17, that is, the proportional parameter, Integral parameters and differential parameters. In an embodiment, the modulation equation indicates that the temperature error value is multiplied by the difference between the first parameter value and the second parameter value, and the second parameter value is added to obtain a temperature drop corresponding to the proportional parameter, the integral parameter, or the differential parameter. The value of the parameter, such as the following equation:

Where K is the value of the cooling parameter; K1 is the first parameter value; K2 is the second parameter value.

In general, PID control parameters are obtained using the Tyreus-Luyben method or the Ziegler-Nichols method. The Tyreus-Luyben method is a parameter control method for a robust system. The defined temperature system is expressed by the following equation:

among them , and They are the system gain, the time delay, and the time constant. This differential temperature of the system via the system (System identification) limits _a gain constant and the limit cycle constant Ku-Pu after _1, respectively to obtain a scale parameter P _1, the integral parameter I ₁ and the derivative parameter D ₁ according to the following relationship.

P ₁ =Ku ₂ /2.2

I ₁ =Pu ₁ /0.45

D ₁ =Pu ₁ /6.3

The Ziegler-Nichols method is a parameter control method for a stable system, and the defined temperature system is expressed by the following equation:

The parameter symbols are the same as those in the above Ziegler-Nichols method, and will not be described here. Similarly, after the temperature system systematically identifies the limit gain constant Ku ₂ and the limit period constant Pu ₂ , the proportional parameter P ₂ , the integral parameter I _{2 ,} and the differential parameter D ₂ can be respectively obtained according to the following relationship.

P ₂ =Ku ₂ /1.7

I ₂ =Pu ₂ /2

D ₂ =Pu ₂ /8

Comparing the PID control parameters obtained by the above two methods, the PID control parameters obtained by the Tyreus-Luyben method can achieve stable control in most temperature ranges, but the control process consumes energy; and the Ziegler-Nichols method achieves The PID control parameter can only stably control the fan 11 in a small range of linear intervals, that is, near a set-point.

Therefore, in an embodiment of the present invention, the parameter adjustment unit 15 may use the value of one of the PID control parameters obtained by the Tyreus-Luyben method as the first parameter value, and control the PID obtained by the Ziegler-Nichols method. The value of one of the parameters is used as the second parameter value to calculate the value of the temperature drop parameter in the combination of the temperature drop parameters. For example, the parameter adjustment unit 15 can calculate the cooling parameter corresponding to the proportional parameter in the combination of the cooling parameter according to the proportional parameter obtained by the Tyreus-Luyben method and the proportional parameter obtained by the Ziegler-Nichols method, and corresponds to the integral parameter and the differential parameter. The cooling parameters of the parameters are also available in the same way. As the temperature error value decreases (ie, the detected temperature value is closer to the target temperature value), the temperature drop parameter in the cooling parameter combination is closer to the PID control parameter obtained by the Ziegler-Nichols method. In this way, the parameter adjustment unit 15 can adaptively adjust the temperature drop parameter according to the temperature error value to achieve a stable and low power consumption control process.

Next, in step S24, the PID controller 17 obtains the temperature error value from the parameter adjustment unit 15 and determines whether the temperature error value is greater than the determination threshold, wherein the determination threshold may be a preset value in the PID controller 17 or by the user. Make the setting, for example, 0.3. In step S25, when the temperature error value is greater than the determination threshold, the PID controller 17 sets its control parameter to an initial parameter combination, wherein the initial parameter combination includes a plurality of initial parameters respectively corresponding to the proportional parameter, the integral parameter, and the differential parameter, and These initial parameters are all equal to a predetermined value, such as a value of zero or approximately zero. In this way, it is possible to avoid the situation that the rotational speed of the fan 11 rises sharply due to a large temperature difference and the addition of control parameters when the controlled zone is initially started, resulting in excessive cooling and unnecessary power consumption. When the temperature error value is greater than the determination threshold, as shown in step S26, the PID controller 17 sets the control parameters to control the fan 11 according to the combination of the temperature reduction parameters calculated by the parameter adjustment unit 15.

For comparison with the temperature control method and the conventional temperature control method described in the above embodiments, please refer to FIG. 3A and FIG. 3B, wherein FIG. 3A is a time-fan according to a temperature control method according to an embodiment of the present invention and the prior art. The duty cycle diagram, and FIG. 3B is a time-temperature diagram of the temperature control method according to an embodiment of the invention and the prior art. As shown in Figures 3A and 3B, at the initial stage of the controlled zone, the temperature error value is quite large at this time, and controlling the fan with a conventional temperature control method will greatly increase its duty ratio. However, the temperature control method provided by the embodiment of the present invention can determine that the temperature error value is greater than the determination threshold value at this stage, thereby setting the PID control parameter to zero, reducing excessive energy consumption, and avoiding excessive increase of the fan speed, resulting in excessive controlled area. Cooling situation. Further, when the temperature error value is equal to or smaller than the determination threshold, the temperature control method provided by the embodiment of the present invention dynamically adjusts the PID control parameter according to the temperature error value and the modulation equation to reduce the oscillation of the fan speed (Oscillation). Phenomenon, smoothly enter the steady-state response area.

With the above structure, the temperature control device and the control method thereof disclosed in the present invention control the fan with the initial parameter combination when the controlled area is initially started, and according to the temperature error value and the modulation when the temperature error value is equal to or smaller than the determination threshold value. The equation dynamically adjusts the control parameters of the PID controller to prevent the fan speed from rising sharply due to the temperature difference and the addition of control parameters in the transient response interval, resulting in excessive cooling and avoiding entering the steady-state response region. The ambient temperature overshoot condition and the fluctuation of the fan speed in the steady state response range. In addition, the control method of automatically obtaining the PID control parameters through the temperature control device not only achieves optimal control, but also reduces the labor cost for the operator to perform parameter adjustment.

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‧‧‧Parameter adjustment unit

17‧‧‧Proportional Integral Derivative Controller

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 temperature control method according to an embodiment of the invention. 3A is a time-fan duty cycle diagram of a temperature control method according to an embodiment of the invention and the prior art. FIG. 3B is a time-temperature diagram of a temperature control method according to an embodiment of the invention and the prior art.

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 value, wherein the temperature sensor is configured to be controlled by the temperature sensor And the detected temperature value is used to indicate the temperature of the controlled area; a parameter adjusting unit is electrically connected to the temperature sensor, according to the detected temperature value, an external ambient temperature value, and a Calculating a temperature error value according to the target temperature value, and calculating a cooling parameter combination according to the temperature error value and a modulation equation; and a proportional integral derivative (PID) controller connected to the fan, the temperature sensor and The parameter adjustment unit, when the temperature error value is greater than a determination threshold, the fan controller controls the fan according to an initial parameter combination, and when the temperature error value is equal to or less than the determination threshold, the PID controller is configured according to the cooling The parameter combination controls the fan; 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 is configured to control an intrinsic ambient temperature or a component temperature below the target temperature, and the temperature sensor obtains the detected temperature value according to the intrinsic ambient temperature or the component temperature. The temperature control device of claim 1, further comprising a second temperature sensor for being disposed outside the controlled area to obtain the external ambient temperature. The temperature control device of claim 1, wherein the preset value is zero. The temperature control device of claim 1, wherein the parameter adjustment unit divides the difference between the target temperature value and the detected temperature value and the difference between the target temperature value and the external ambient temperature value to obtain This temperature error value. A temperature control method is applicable to a temperature control device including a PID 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 includes: obtaining a detected temperature value, The detected temperature value is used to indicate the temperature of the controlled area; a temperature error value is calculated according to the detected temperature value, an external ambient temperature value, and a target temperature value; The modulation equation is calculated to obtain a combination of cooling parameters; when the temperature error value is greater than a determination threshold, the plurality of control parameters of the PID controller are set as an initial parameter combination to control the fan, wherein the initial parameter combination includes Controlling a plurality of initial parameters of the same number of parameters, and the initial parameters are equal to a preset value; and when the temperature error value is equal to or less than the determination threshold, setting the PID controller according to the cooling parameter combination Control parameters to control the fan. The temperature control method of claim 6, wherein the preset value is zero. The temperature control method according to claim 6, wherein the temperature error value is divided by a difference between the target temperature value and the detected temperature value and a difference between the target temperature value and the external ambient temperature value. get. The temperature control method of claim 6, wherein the modulation equation indicates that the temperature error value is multiplied by a difference between a first parameter value and a second parameter value, and the second parameter value is added to obtain the The value of one of the plurality of cooling parameters of the cooling parameter combination. The temperature control method according to claim 6, wherein the first parameter value is one of a plurality of PID control parameters obtained according to the Ziegler-Nichols method, and the second parameter value is obtained according to the Tyreus-Luyben method. One of the multiple PID control parameters.