Fan rotation speed acquisition method and fan control assembly

Abstract

The application discloses a fan rotating speed acquisition method and a fan control assembly, and relates to the technical field of fan control. The method determines the duty cycle of a first control signal based on the target rotating speed of a fan, controls the rotating speed of the fan according to the duty cycle of the first control signal to generate a speed signal, and acquires the actual rotating speed of a first rotor and the actual rotating speed of a second rotor through the speed signal when the fan type is determined to be a double-rotor fan according to the speed signal of the fan. Therefore, the method can realize the control of single-rotor fans and double-rotor fans, can automatically identify whether a single-rotor fan or a double-rotor fan is connected according to the speed signal, and improves the fault diagnosis accuracy.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fan control, and particularly relates to a fan rotating speed acquisition method and a fan control assembly. BACKGROUND

[0002] Efficient and stable operation of a server cooling system is crucial. For a server using air cooling, the internal cooling system is usually composed of multiple cooling fans, and the fan types include single-rotor cooling fans and double-rotor cooling fans. To meet the regulation and control requirements of the cooling system, a fan controller needs to control the target rotating speed of the fan and acquire the actual rotating speed of the fan.

[0003] In the related art, to be compatible with single-rotor fans and double-rotor fans, the fan controller controls the target rotating speed of the fan through a pulse width modulation signal line, and acquires the actual rotating speed of the fan through two speed signal lines. When a single-rotor fan is used, the actual rotating speed of the fan is acquired through one speed signal line, and the two cannot be compatible. In addition, when a double-rotor fan is used, if one of the speed signal lines has no signal, it cannot be determined whether a single-rotor fan is connected or a double-rotor fan is damaged. SUMMARY

[0004] The present application provides a fan rotating speed acquisition method and a fan control assembly to at least solve the problem in the related art that a double-rotor fan cannot be controlled based on the control circuit of a single-rotor fan.

[0005] The present application provides a fan rotating speed acquisition method, which includes: determining the duty cycle of a first control signal based on the target rotating speed of the fan; regulating the rotating speed of the fan according to the duty cycle of the first control signal to generate a speed signal; and in the case where the fan type is determined to be a double-rotor fan based on the speed signal of the fan, acquiring the actual rotating speed of a first rotor and the actual rotating speed of a second rotor according to the speed signal.

[0006] The present application also provides a fan control assembly, which includes: a first signal line, a second signal line and a controller, the first signal line is connected to the signal input end of the fan and is used to transmit a first control signal to the fan, the second signal line is connected to the signal output end of the fan and is used to receive a speed signal of the fan, and the controller is configured to determine the duty cycle of the first control signal based on the target rotating speed of the fan, regulate the rotating speed of the fan according to the duty cycle of the first control signal to generate a speed signal, and in the case where the fan type is determined to be a double-rotor fan based on the speed signal of the fan, acquire the actual rotating speed of a first rotor and the actual rotating speed of a second rotor according to the speed signal.

[0007] Through the application, since the fan rotating speed is controlled through the first control signal, the actual rotating speed of the fan is acquired through the speed signal, two signal lines, the first signal line and the second signal line, are compatible with the control of the single-rotor fan and the double-rotor fan, and based on the speed signal, it can be automatically identified whether the single-rotor fan or the double-rotor fan is connected, the problem that the control circuit based on the single-rotor fan cannot realize the control of the double-rotor fan in the related art can be solved, and the technical effect of improving the fault diagnosis accuracy is achieved. BRIEF DESCRIPTION OF DRAWINGS

[0008] In order to more clearly illustrate the embodiments of the application, the drawings needed in the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0009] Figure 1 The control interface schematic diagram of the single-rotor fan of the server in the related art is shown in FIG. 1.

[0010] Figure 2 The control interface schematic diagram of the double-rotor fan of the server in the related art is shown in FIG. 2.

[0011] Figure 3 The control interface and signal flow conversion schematic diagram of the server compatible with the single-rotor fan and the double-rotor fan in the related art is shown in FIG. 3.

[0012] Figure 4 The flowchart of the rotating speed acquisition method of the fan provided by the embodiment of the application is shown in FIG. 4.

[0013] Figure 5 The cycle schematic diagram of the pulse width modulation signal of one specific embodiment of the application is shown in FIG. 5.

[0014] Figure 6 The control schematic diagram of the double-rotor fan of the server of one specific embodiment of the application is shown in FIG. 6.

[0015] Figure 7 The first control signal waveform schematic diagram of one specific embodiment of the application is shown in FIG. 7.

[0016] Figure 8 The second control signal waveform schematic diagram of one specific embodiment of the application is shown in FIG. 8.

[0017] Figure 9 The speed signal waveform schematic diagram of one specific embodiment of the application is shown in FIG. 9.

[0018] Figure 10 The control schematic diagram of the single-rotor fan of the server of one specific embodiment of the application is shown in FIG. 10.

[0019] Figure 11A waveform diagram of a single-rotor fan speed signal for one embodiment of the present application;

[0020] Figure 12 A control flow diagram of a fan controller controlling a double-rotor fan for one embodiment of the present application;

[0021] Figure 13 A flowchart of a fan speed acquisition method for one embodiment of the present application;

[0022] Figure 14 A block diagram of a fan control assembly provided by an embodiment of the present application. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0024] It should be noted that, in the description of the present application, the terms “comprise”, “contain” or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such a process, method, article or device. The terms “first”, “second” and the like in the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence.

[0025] In order for those skilled in the art to better understand the technical solutions of the present application, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0026] The control of a common single-rotor fan is performed by one pulse width modulation signal and one speed signal for fan speed regulation and speed feedback, Figure 1 A control interface diagram of a single-rotor fan of a server in the related art. The fan controller sends a pulse width modulation signal with a fixed frequency and a variable duty cycle to the fan, the fan measures the duty cycle of the pulse width modulation signal to regulate the speed, and sends a speed signal with a variable frequency to the fan controller, and the fan controller converts the frequency of the speed signal to obtain the actual speed of the fan.

[0027] For a low-configuration server, a single-rotor fan can meet the system heat dissipation requirement, but for a high-configuration server, a double-rotor fan is needed to improve the system heat dissipation capability, Figure 2This is a schematic diagram of the control interface for a dual-rotor fan in a server, as described in related technologies. The front and rear rotors of a dual-rotor fan share a single pulse-width modulation (PWM) signal, but since the two rotors operate independently, two separate speed signals are needed to feed back their actual rotational speeds to the fan controller.

[0028] When server models require compatibility with both single-rotor and dual-rotor fans due to configuration differences, the fan controller must simultaneously support the pulse width modulation (PWM) signal and speed signal interfaces for single-rotor fans, and the PWM signal, speed signal 1, and speed signal 2 interfaces for dual-rotor fans. For example... Figure 3 As shown, the fan interface includes a pulse width modulation signal, speed signal 1, and speed signal 2, supporting dual-rotor fans and compatible with single-rotor fans. A frequency duty cycle generator is used to generate periodic pulse signals with specific frequencies and duty cycles, and a frequency duty cycle measurement unit is used to receive and measure the frequency and duty cycle of the periodic pulse signals.

[0029] When a dual-rotor fan is connected, both the input and output rotors receive the same pulse-width modulation (PWM) signal from the fan controller. The two rotors operate independently, each feeding back speed signals 1 and 2 to the fan controller. Two frequency duty cycle measurement units in the fan controller measure speed signals 1 and 2 respectively, obtaining the actual speeds of the two rotors on the input and output sides. When a single-rotor fan is connected, only the PWM signal and speed signal 1 are used; speed signal 2 is not used. The fan controller adjusts the fan speed using the PWM signal and obtains the actual fan speed through speed signal 1. Therefore, this solution suffers from high cost and resource idleness.

[0030] This solution also has the following problem: when a dual-rotor fan is connected and its output rotor is damaged, speed signal 1 has a signal output, but speed signal 2 does not have a signal output, which is the same as the signal behavior when a single-rotor fan is connected. This makes it impossible for the fan controller to determine whether the output rotor of the single-rotor fan or the dual-rotor fan is damaged. It is necessary to manually configure the fan controller to tell whether a single-rotor fan or a dual-rotor fan is used in order to determine the fan fault.

[0031] To address at least one of the aforementioned technical problems, this application proposes a method for obtaining fan speed. The method controls the fan speed through a first control signal and obtains the actual fan speed through a speed signal. The method uses two signal lines, a first signal line and a second signal line, to be compatible with the control of both single-rotor and dual-rotor fans. Furthermore, based on the speed signal, it can automatically identify whether the fan is a single-rotor or dual-rotor fan, thereby improving the accuracy of fault diagnosis.

[0032] The method for obtaining the fan speed according to an embodiment of this application will be described in detail below with reference to the accompanying drawings.

[0033] As Figure 4 shown, the fan speed acquisition method of the embodiment of the application can include:

[0034] S1, determining the duty cycle of the first control signal based on the target speed of the fan.

[0035] Specifically, the first control signal can adopt a pulse width modulation signal, which is a periodic high-low level pulse signal, and information or control equipment is transmitted by changing the duty cycle, which is the ratio of the high level duration in a cycle of the pulse width modulation signal to the total cycle, Figure 5 As shown in the cycle diagram of the pulse width modulation signal, Tp is a cycle, Th is the time of maintaining high level in a cycle of the pulse width modulation signal, and the duty cycle Duty=Th / Tp.

[0036] The fan speed is usually related to the input voltage, the higher the voltage, the faster the speed, and the pulse width modulation signal controls the average voltage by adjusting the ratio of high level time to cycle (duty cycle), so the duty cycle of the first control signal can be determined by the target speed of the fan, for example, the target speed is derived from the target voltage according to the fan characteristic curve, and the target voltage is divided by the rated voltage to obtain the duty cycle of the first control signal. The specific determination method of the duty cycle is not limited.

[0037] S2, adjusting the speed of the fan according to the duty cycle of the first control signal to generate a speed signal.

[0038] Specifically, the speed signal is the speed signal of the fan, which is also a periodic high-low level pulse signal with clear high-low level jump, and the cycle and duty cycle are variable. The duty cycle of the first control signal can be determined based on the target speed and the rated speed of the fan, and the speed of the fan is adjusted based on the duty cycle of the first control signal to make the speed of the fan reach the target speed. During the regulation process, the fan detects the current speed in real time and converts it into a speed signal, which is used to feed back to the fan controller to form a closed-loop regulation to ensure that the actual speed is consistent with the target speed.

[0039] S3, in the case where the fan type is determined to be a double-rotor fan according to the speed signal of the fan, the actual speed of the first rotor and the actual speed of the second rotor are obtained according to the speed signal.

[0040] Specifically, the period and duty cycle of the speed signal of the fan can be used to identify whether a single-rotor fan or a double-rotor fan is connected, for example, different duty cycles can be used to identify the fan type, and the specific identification method is not limited. When it is determined that a double-rotor fan is connected, the actual speed of the first rotor and the actual speed of the second rotor can be calculated based on the speed signal to form a closed-loop control of the fan, for example, the actual speed of the first rotor is obtained based on the period of the speed signal, and the actual speed of the second rotor is obtained based on the duty cycle of the speed signal.

[0041] Therefore, the embodiment controls the speed of the fan through the first control signal, obtains the actual speed of the fan through the speed signal, uses two signal lines, i.e., the first signal line and the second signal line, to compatibly control the single-rotor fan and the double-rotor fan, and automatically identifies whether a single-rotor fan or a double-rotor fan is connected based on the speed signal, thereby reducing the fan control cost and improving the fault diagnosis accuracy and adaptive flexibility of the fan.

[0042] In some embodiments of the present application, when the fan type is a double-rotor fan, the speed of the fan is regulated based on the first control signal to generate a speed signal, including: regulating the speed of the first rotor based on the duty cycle of the first control signal and obtaining the actual speed of the first rotor; determining a second control signal based on the actual speed of the first rotor and the duty cycle of the first control signal; regulating the speed of the second rotor based on the second control signal to obtain the actual speed of the second rotor; and determining the speed signal of the fan based on the actual speed of the first rotor and the actual speed of the second rotor.

[0043] Specifically, as shown in Figure 6 The double-rotor fan is built-in with two independent rotors, i.e., an input-side rotor and an output-side rotor, the input-side rotor is the first rotor, the output-side rotor is the second rotor, and the two rotors are driven by respective motors. The input-side rotor, the output-side rotor, and the fan controller are respectively built-in with a frequency duty cycle measurement unit and a frequency duty cycle generator. The frequency duty cycle measurement unit is used to measure the frequency and duty cycle of a signal, and the frequency duty cycle generator is used to generate a signal with a specific frequency and duty cycle. The second control signal can be a relay signal, which is also a periodic high-low level pulse signal with variable period and duty cycle.

[0044] The frequency duty cycle generator of the fan controller determines the duty cycle of the first control signal based on the target speed and the rated speed of the first rotor, and sends the first control signal with a fixed frequency and a variable duty cycle to the first rotor. The frequency duty cycle measurement unit of the first rotor measures the first control signal, and regulates the speed SpeedInRef of the first rotor based on the duty cycle of the first control signal. Figure 7As shown, the first control signal waveform generated by the frequency duty cycle generator in the fan controller has a period Tp, Tph1 and Tph2 are two time periods during which the first control signal is high, and the duty cycle DutyP=Tph / Tp. Since Tph1 and Tph2 are different, the corresponding duty cycles are also different, but the duty cycle of the first control signal always ranges from 0% to 100%, and the target speed of the fan ranges from 0% to 100% of the rated speed. The calculation formula of the duty cycle of the first control signal is:

[0045] DutyP=SpeedInRef / SpeedInMax,

[0046] wherein the rated speed SpeedInMax of the first rotor is known by referring to the instruction manual of the fan, and thus the speed of the first rotor can be regulated according to the duty cycle of the first control signal, Figure 7 The first control signal waveform is shown, in which the target speed duty cycle changes from DutyP1 to DutyP2. The first rotor adjusts the current or voltage output to the motor to match the actual speed to the target speed, and the actual speed SpeedIn of the first rotor is detected in real time during the regulation process.

[0047] The frequency duty cycle generator of the first rotor generates a second control signal according to the actual speed SpeedIn of the first rotor and the duty cycle DutyP of the first control signal, and the period of the second control signal is defined as Tr and the duty cycle is defined as DutyR. The frequency duty cycle measurement unit of the second rotor measures the second control signal, determines the target speed SpeedOutRef of the second rotor according to the duty cycle of the second control signal, and the second rotor adjusts the current or voltage output to the motor to match the actual speed to the target speed, and the actual speed SpeedOut of the second rotor is detected in real time during the regulation process. The speed signal of the fan is obtained by corresponding calculation using the actual speed SpeedIn of the first rotor and the actual speed SpeedOut of the second rotor, and the speed signal is transmitted to the frequency duty cycle measurement unit of the fan controller.

[0048] In this embodiment, the speed of the first rotor is regulated by the first control signal to obtain the actual speed of the first rotor, and the speed of the second rotor is regulated by the second control signal to obtain the actual speed of the second rotor, and finally the speed signal is determined based on the two actual speeds, which can realize precise speed control, reduce mutual interference, and improve the accuracy of speed control and the dynamic adaptability of the system.

[0049] In some embodiments of the present application, the second control signal comprises a period and a duty cycle, and the second control signal is determined based on the actual rotation speed of the first rotor and the duty cycle of the first control signal, comprising: determining the period of the second control signal according to the actual rotation speed of the first rotor; and determining the duty cycle of the second control signal according to the duty cycle of the first control signal.

[0050] Specifically, the frequency duty cycle generator of the first rotor generates the period of the second control signal according to the actual rotation speed of the first rotor, and generates the duty cycle of the second control signal based on the duty cycle of the first control signal. For example, considering that the duty cycle of the first control signal takes a value of [0%, 100%], in order to avoid losing frequency information at 0% and 100%, it is necessary to reduce the range of the duty cycle of the second control signal, for example, to [25%, 75%].

[0051] This embodiment determines the period and duty cycle of the second control signal based on the actual rotation speed of the first rotor and the duty cycle of the first control signal, so that the second control signal can be dynamically adjusted based on the real-time situation of the first rotor, ensuring the operation coordination of the two rotors, avoiding the coordination disorder caused by independent control, and combining the actual rotation speed feedback, the period and duty cycle of the second control signal can be optimized in a targeted manner, so that the action of the second rotor is more in line with the system requirements, reduces the error, and improves the stability and accuracy of the overall operation.

[0052] In some embodiments of the present application, the rotation speed acquisition method of the fan further comprises: determining the period of the second control signal based on the ratio of the first preset value to the actual rotation speed of the first rotor; and determining the duty cycle of the second control signal based on the sum of half of the duty cycle of the first control signal and the first preset ratio. The first preset ratio can be calibrated according to the actual situation, and the first preset ratio can be 25%.

[0053] Specifically, the period Tr of the second control signal changes with the actual rotation speed SpeedIn of the first rotor, and the calculation formula of the period Tr of the second control signal is defined as:

[0054] Tr=30 / SpeedIn,

[0055] Wherein, the second control signal is a pulse signal output by a frequency duty cycle generator built-in the first rotor, used to feedback the actual rotation speed of the first rotor, the fan generates a fixed number of pulses (usually 2) for each rotation, Tr is the period of the second control signal, the unit is second, the number of pulses per second is 1 / Tr, since each circle corresponds to 2 pulses, the number of circles per second (i.e. rotation speed) is (1 / Tr) / 2=1 / (2Tr), and the unit is converted to the more commonly used revolutions per minute, which needs to be multiplied by 60, i.e. actual rotation speed=1 / (2Tr)×60=30 / Tr, which is the basis for setting the first preset value to 30.

[0056] Considering that the value range of DutyP is [0%, 100%], in order to avoid losing frequency information at 0% and 100%, the range of the duty ratio of the second control signal DutyR needs to be reduced, here reduced to [25%, 75%], and the calculation formula of the duty ratio of the second control signal DutyR is defined as:

[0057] DutyR=DutyP / 2+25%,

[0058] wherein the value range of DutyP is [0%, 100%], and the value range of the duty ratio of the second control signal DutyR needs to be reduced to [25%, 75%], half of the duty ratio of the first control signal DutyP is [0%, 50%], and adding 25% is just the reduced range of the duty ratio of the second control signal DutyR, so the first preset ratio is set to 25%. And the reason for avoiding losing frequency information at 0% and 100% is that the duty ratio is 0%, which means that the signal is all low, and the duty ratio is 100%, which means that the signal is all high, and the signal waveforms of the two cases are straight lines, and the periodic changes cannot be detected, so the frequency information will be lost, so the range of the duty ratio of the second control signal needs to be reduced, but the first control signal only identifies the duty ratio to control the fan speed, and does not need to identify the frequency, so the range does not need to be changed, and can be kept as [0%, 100%].

[0059] Figure 8 The waveform of the second control signal is shown, the period of the second control signal is used to transmit the actual speed of the first rotor to the second rotor, the duty ratio of the second control signal is used to transmit the duty ratio value of the first control signal to the second rotor, the time of the second control signal maintaining high level is Trh=DutyR×Tr, the duty ratio of the second control signal changes from DutyR1 to DutyR2, and the high level time changes from Trh1 to Trh2, corresponding to Figure 7 the process of the duty ratio of the first control signal changing from Duty1 to Duty2.

[0060] This embodiment calculates the period and duty ratio of the second control signal through the actual speed of the first rotor and the duty ratio of the first control signal, transmits the actual speed of the first rotor and the duty ratio value of the first control signal to the second rotor through the second control signal, realizes the cooperative control of the double rotors, guarantees the correlation and consistency of the operation of the two, improves the synchronization and response efficiency of the system control, and simplifies the control process.

[0061] In some embodiments of the present application, the speed of the second rotor is regulated according to the second control signal, including: determining the target speed of the second rotor according to the product of the duty ratio of the second control signal and the rated speed of the second rotor; and regulating the speed of the second rotor based on the duty ratio of the second control signal and the target speed of the second rotor.

[0062] Specifically, the frequency duty ratio measuring unit of the second rotor measures the period and duty ratio of the second control signal, regulates the speed of the second rotor according to the duty ratio, the target speed of the second rotor is SpeedOutRef, the rated speed of the second rotor is SpeedOutMax, and the calculation formula of the target speed of the second rotor is:

[0063] SpeedOutRef=SpeedOutMax×DutyR,

[0064] Wherein, the rated speed SpeedOutMax of the second rotor is known data confirmed by consulting the instruction manual of the fan, therefore, the speed of the second rotor can be regulated according to the duty ratio of the second control signal, the second rotor adjusts the current or voltage output to the motor to match the actual speed SpeedOut with the target speed SpeedOutRef, and the current speed is detected in real time and the actual speed SpeedOut is fed back during the regulation process.

[0065] Meanwhile, the actual speed of the first rotor is calculated according to the period of the second control signal, that is, the actual speed of the first rotor is calculated by the formula SpeedIn=30 / Tr.

[0066] This embodiment regulates the speed of the second rotor through the duty ratio of the second control signal, and calculates the actual speed of the first rotor through the period of the second control signal, and simultaneously completes the regulation of the second rotor and the calculation of the speed of the first rotor by means of the same control signal, so that the running state monitoring and control of the two rotors are linked, the delay of signal transmission and processing is reduced, the response speed and running coordination of the whole system are improved, the control structure is simplified, and the cost is reduced.

[0067] In some embodiments of the present application, the speed signal of the fan includes a period and a duty cycle, and the speed signal of the fan is determined based on the actual speed of the first rotor and the actual speed of the second rotor, including: determining the period of the speed signal according to the actual speed of the first rotor; obtaining a ratio of the actual speed of the second rotor to the actual speed of the first rotor; in the case that the ratio is less than or equal to a second preset value, determining the duty cycle of the speed signal according to a product of the ratio and a second preset ratio plus a third preset ratio; in the case that the ratio is greater than the second preset value, determining the duty cycle of the speed signal according to a product of the ratio and a fourth preset ratio plus a fifth preset ratio, wherein the third preset ratio is less than the fifth preset ratio.

[0068] Specifically, the frequency duty cycle generator of the second rotor generates a speed signal, which is fed back to the frequency duty cycle measurement unit of the fan controller, Figure 9 As shown, the period of the speed signal is used to feedback the speed of the first rotor, so the period of the speed signal is the same as the period of the second control signal, and the period of the speed signal is set to Tt, which is determined according to the actual speed of the first rotor, and the calculation formula is:

[0069] Tt=30 / SpeedIn,

[0070] The duty cycle of the speed signal is used to feedback the speed of the second rotor, and the duty cycle of the speed signal is calculated by: Figure 9 As shown, the duty cycle of the speed signal is set to DutyT, and if the time of maintaining a high level is Tth, then the duty cycle DutyT=Tth / Tt. In order to avoid losing frequency information at 0% and 100% duty cycle, it is necessary to reduce the range of the duty cycle of the speed signal, and the value range of the duty cycle of the speed signal is defined as [10%, 90%].

[0071] By comparing the actual speed of the second rotor SpeedOut and the actual speed of the first rotor SpeedIn calculated by the period of the second control signal, the ratio of the actual speed of the second rotor to the actual speed of the first rotor is obtained as SpeedOut / SpeedIn, and when SpeedOut / SpeedIn≤2, the calculation formula of the duty cycle DutyT of the speed signal is defined as:

[0072] DutyT=(SpeedOut / SpeedIn)×15%+10%,

[0073] Wherein, 2 is the second preset value, 15% is the second preset ratio, and 10% is the third preset ratio, at this time the range of SpeedOut / SpeedIn is [0, 2], and the value range of DutyT is [10%, 40%].

[0074] When SpeedOut / SpeedIn>2, the duty cycle DutyT of the speed signal is calculated according to the following formula:

[0075] DutyT=(SpeedOut / SpeedIn)×10%+40%,

[0076] wherein 10% is the fourth preset ratio, 40% is the fifth preset ratio, the range of SpeedOut / SpeedIn is (2, 5], and the range of DutyT is [60%, 90%]. The overall range of DutyT is [10%, 40%] and [60%, 90%], which is consistent with the predefined range [10%, 90%] of the duty cycle of the speed signal. The second preset value, the second preset ratio, the third preset ratio, the fourth preset ratio, and the fifth preset ratio are all set according to the predefined range of DutyT.

[0077] The embodiment determines the speed signal of the fan by the actual rotational speed of the first rotor and the actual rotational speed of the second rotor, including the period and duty cycle of the speed signal, to feed back the speed signal to the fan controller, realize the closed loop of fan control, improve the control accuracy, make the fan speed regulation more consistent with the actual demand, optimize the fan performance, and stably and accurately control the fan to run efficiently under different working conditions, reduce unnecessary energy consumption, and prolong the service life of the fan.

[0078] In some embodiments of the present application, the fan type is determined to be a double-rotor fan according to the speed signal of the fan, including: in the case that the duty cycle of the speed signal is less than or equal to a first preset duty cycle threshold or greater than or equal to a second preset duty cycle threshold, the fan type is determined to be a double-rotor fan, wherein the second preset duty cycle threshold is greater than the first preset duty cycle threshold.

[0079] Specifically, the range of the duty cycle of the speed signal is [10%, 90%], and if DutyT≤40% or DutyT≥60%, the fan type is determined to be a double-rotor fan, wherein 40% is the first preset duty cycle threshold, 60% is the second preset duty cycle threshold, and the first preset duty cycle threshold and the second preset duty cycle threshold are set according to the predefined range of DutyT, in order to distinguish the double-rotor fan from the single-rotor fan.

[0080] The embodiment determines the fan type to be a double-rotor fan according to the range of the duty cycle of the speed signal, realizes the distinction between the double-rotor fan and the single-rotor fan, can accurately judge whether the fault is of the double-rotor fan or the single-rotor fan when the fan fails, avoids misjudgment caused by type confusion, and improves the accuracy and efficiency of fault diagnosis.

[0081] In some embodiments of the present application, the method for obtaining the rotating speed of the fan further comprises: in a case where the duty cycle of the speed signal is a third preset duty cycle threshold, determining that the fan type is a single-rotor fan, wherein the third preset duty cycle threshold is greater than the first preset duty cycle threshold and less than the second preset duty cycle threshold.

[0082] Specifically, the duty cycle of the speed signal is in a range of [10%, 90%], and if DutyT=50%, it is determined that the fan type is a single-rotor fan, wherein 50% is the third preset duty cycle threshold, and the third preset duty cycle threshold is set according to the predefined value range of DutyT, and whether the double-rotor fan or the single-rotor fan is accessed can be identified according to the duty cycle value of the speed signal.

[0083] Figure 10 For the control schematic diagram when the fan interface accesses the single-rotor fan, the frequency duty cycle generator of the fan controller sends the first control signal with the fixed frequency and the variable duty cycle to the fan through the first signal line, the fan frequency duty cycle measurement unit measures the duty cycle value of the first control signal to regulate the rotating speed, and generates the speed signal through the frequency duty cycle generator to send the speed signal with the fixed duty cycle of 50% and the variable frequency, and the frequency duty cycle measurement unit of the fan controller measures the frequency of the speed signal to calculate the actual rotating speed of the fan. Figure 11 For the waveform schematic diagram of the speed signal when the fan interface accesses the single-rotor fan, the period of the speed signal is Tt, the time of maintaining the high level is Tt / 2, and the duty cycle is 50%.

[0084] This embodiment determines the fan type as the single-rotor fan according to the value range of the duty cycle of the speed signal, realizes the differentiation between the double-rotor fan and the single-rotor fan, can accurately judge whether the fault is of the double-rotor fan or the single-rotor fan when the fan fails, avoids the misjudgment caused by the type confusion, and improves the accuracy and efficiency of the fault diagnosis.

[0085] In some embodiments of the present application, the first control signal is determined based on the target rotating speed of the fan, comprising: determining the duty cycle of the first control signal based on the ratio between the target rotating speed of the fan and the rated rotating speed of the fan.

[0086] Specifically, in the fan controller, after the target rotating speed is set, the duty cycle of the first control signal is calculated, and the first control signal with the fixed period is generated through the frequency duty cycle generator, wherein the target rotating speed is SpeedRef, the rated rotating speed is SpeedMax, and the duty cycle of the first control signal is Duty, and the duty cycle calculation formula is:

[0087] Duty=SpeedRef / SpeedMax,

[0088] Whether the single rotor fan or the double rotor fan is accessed, the duty cycle of the first control signal can be determined by setting the target speed of the fan, the single rotor fan has one rotor, and the double rotor fan determines the duty cycle of the first control signal by setting the target speed of the first rotor.

[0089] The embodiment determines the duty cycle of the first control signal through the target speed of the fan, and transmits it to the fan through the first signal line to regulate and control the fan, so that the fan speed can be accurately matched with the target value, ensuring that the fan operates under the expected working condition. The first control signal transmission is stable and responds quickly, which can quickly adjust the fan state, reduces the regulation and control delay, and improves the control efficiency.

[0090] Further, the frequency duty cycle measurement unit of the fan controller measures the period and duty cycle of the speed signal, calculates the actual speed of the first rotor according to the period Tt of the speed signal through the formula SpeedIn=30 / Tt, judges the single / double rotor type of the accessed fan according to the duty cycle DutyT of the speed signal, if DutyT=50%, the fan is a single rotor fan, if DutyT≤40% or DutyT≥60%, the fan is a double rotor fan. And combined with the actual speed of the first rotor SpeedIn, the actual speed of the second rotor is calculated, if DutyT≤40%, the actual speed of the second rotor is calculated according to the formula DutyT=(SpeedOut / SpeedIn)×15%+10% is deformed, and the calculation formula of the actual speed of the second rotor is:

[0091] SpeedOut=(DutyT-10%) / 15%×SpeedIn,

[0092] If DutyT≥60%, the calculation formula of the actual speed of the second rotor is obtained by deforming the formula DutyT=(SpeedOut / SpeedIn)×10%+40%:

[0093] SpeedOut=(DutyT-40%) / 10%×SpeedIn.

[0094] Thus, the speed control and feedback between the fan controller and the fan are completed, the target speed of the fan can be adjusted according to the actual heat dissipation demand, the speed fluctuation affecting heat dissipation or energy consumption is avoided, the actual speed of the fan is monitored in real time through the feedback mechanism, and the control signal is dynamically corrected after comparison with the target value, ensuring the accuracy and reliability of the speed control, improving the overall operation efficiency, and prolonging the service life of the equipment.

[0095] Figure 12The control flow diagram of the fan controller controlling the dual-rotor fan is shown. In the fan controller, the target duty ratio DutyP of the first control signal is calculated according to the target rotating speed of the first rotor, and the first control signal is generated by the frequency duty ratio generator in the fan controller and sent to the first rotor of the dual-rotor fan.

[0096] The frequency duty ratio measurement unit of the first rotor obtains the duty ratio DutyP of the first control signal according to the target rotating speed and the rated rotating speed of the first rotor, and regulates the rotating speed of the first rotor based on the target rotating speed of the first rotor and the duty ratio DutyP of the first control signal. The actual rotating speed SpeedIn of the first rotor is obtained, the period Tr of the second control signal is calculated according to the actual rotating speed SpeedIn of the first rotor, and the duty ratio DutyR of the second control signal is calculated according to the duty ratio DutyP of the first control signal. The second control signal is generated by the frequency duty ratio generator of the first rotor and sent to the frequency duty ratio measurement unit of the second rotor.

[0097] The frequency duty ratio measurement unit of the second rotor measures the second control signal to obtain the period Tr and the duty ratio DutyR of the second control signal, calculates the actual rotating speed SpeedIn of the first rotor according to the period Tr of the second control signal, calculates the target rotating speed of the second rotor according to the duty ratio DutyR of the second control signal and the rated rotating speed of the second rotor, and regulates the rotating speed of the second rotor based on the target rotating speed of the second rotor. The actual rotating speed SpeedOut of the second rotor is obtained, and the duty ratio DutyT of the speed signal is calculated according to the actual rotating speed SpeedOut of the second rotor and the actual rotating speed SpeedIn of the first rotor. The period Tt of the speed signal is determined based on the actual rotating speed of the first rotor. The speed signal is generated by the frequency duty ratio generator of the second rotor according to the duty ratio and the period of the speed signal, and sent to the frequency duty ratio measurement unit of the fan controller.

[0098] The frequency duty ratio measurement unit of the fan controller measures the speed signal to obtain the period Tt and the duty ratio DutyT of the speed signal, calculates the actual rotating speed SpeedIn of the first rotor according to the period Tt of the speed signal, and calculates the actual rotating speed SpeedOut of the second rotor according to the duty ratio DutyT of the speed signal and the actual rotating speed SpeedIn of the first rotor. Thus, the speed control and feedback between the fan controller and the dual-rotor fan are completed once.

[0099] As a specific embodiment of the present application, Figure 13 The flowchart of the rotating speed acquisition method of the fan according to some embodiments of the present application is shown as Figure 13 The rotating speed acquisition method of the fan can include the following steps:

[0100] S101, the fan controller determines a first control signal based on a target rotating speed of the fan, and sends the first control signal to the first rotor of the fan through a first signal line.

[0101] S102, the first rotor of the fan measures a duty cycle of the first control signal, controls the rotating speed of the first rotor, and generates a second control signal according to the actual rotating speed of the first rotor and the duty cycle of the first control signal, and sends the second control signal to the second rotor.

[0102] S103, the second rotor of the fan measures a duty cycle and a period of the second control signal, controls the rotating speed of the second rotor, and generates a speed signal according to the actual rotating speed of the second rotor and the duty cycle of the second control signal, and sends the speed signal to the fan controller.

[0103] S104, the fan controller measures the duty cycle and the period of the speed signal, identifies the type of the connected fan, and when the type of the fan is a double-rotor fan, calculates the actual rotating speed of the first rotor and the actual rotating speed of the second rotor to complete the closed-loop control of the fan.

[0104] Therefore, the rotating speed acquisition method of the fan provided in this embodiment uses one first control signal and one speed signal to control the double-rotor fan, the fan controller can calculate the actual rotating speed of the first rotor according to the period of the speed signal, and can calculate the actual rotating speed of the second rotor according to the duty cycle of the speed signal, and can also automatically identify whether the connected fan is a single-rotor fan or a double-rotor fan according to the duty cycle.

[0105] This embodiment determines the duty cycle of the first control signal based on the target rotating speed of the fan, controls the rotating speed of the fan according to the duty cycle of the first control signal to generate a speed signal, and acquires the actual rotating speed of the first rotor and the actual rotating speed of the second rotor through the speed signal when the type of the fan is determined to be a double-rotor fan based on the speed signal of the fan. Therefore, this method controls the rotating speed of the fan through the first control signal, acquires the actual rotating speed of the fan through the speed signal, uses two signal lines, i.e., the first signal line and the second signal line, to control the single-rotor fan and the double-rotor fan, and automatically identifies whether the connected fan is a single-rotor fan or a double-rotor fan according to the speed signal, thereby improving the fault diagnosis accuracy.

[0106] Embodiments of the application also provide a fan control assembly, which comprises Figure 14As shown, the fan control assembly 200 includes a first signal line 210, a second signal line 220 and a controller 230, the first signal line 210 is connected with the signal input end of the fan, used for transmitting the first control signal to the fan, the second signal line 220 is connected with the signal output end of the fan, used for receiving the speed signal of the fan, wherein the controller 230 is configured to determine the duty cycle of the first control signal based on the target rotating speed of the fan, and regulate the rotating speed of the fan according to the duty cycle of the first control signal to generate the speed signal, and in the case that the fan type is determined as the double-rotor fan according to the speed signal of the fan, the actual rotating speed of the first rotor and the actual rotating speed of the second rotor are obtained according to the speed signal.

[0107] The fan control assembly of the embodiment realizes the control of the fan by using two lines of the first signal line and the second signal line, the controller regulates the rotating speed of the fan through the first control signal, and the actual rotating speed of the first rotor and the actual rotating speed of the second rotor are obtained according to the speed signal by measuring the speed signal, which simplifies the control circuit design, reduces the wiring complexity and cost, and at the same time, accurately controls and monitors the fan, improves the system reliability, and helps the system early warning and maintenance.

[0108] Those skilled in the art will further appreciate that the units and algorithm steps of the examples described in connection with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both, and that the described examples are merely illustrative of the principles of the application. In view of the above, the functions of the described examples can be implemented in hardware or software depending on the application and design constraints. Those skilled in the art can use different methods to implement the described functions for specific applications, but such implementation should not be considered beyond the scope of the application.

[0109] The above provides a kind of fan rotating speed acquisition method, fan control assembly and computer readable storage medium provided by the application.The principle and implementation of the present application are described in the specific examples in this paper, the above description of examples is only applicable to help understand the method and core idea of the present application.It should be pointed out that, for the ordinary skilled person in the art, without departing from the principle of the present application, some improvements and modifications can be made to the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. A method of acquiring a rotational speed of a fan, characterized by, The method comprises: determining a duty cycle of a first control signal based on a target speed of the fan; controlling the speed of the fan according to the duty cycle of the first control signal to generate a speed signal; in a case where the fan type is determined to be a double-rotor fan based on the speed signal of the fan, obtaining an actual speed of a first rotor and an actual speed of a second rotor based on the speed signal; wherein, in a case where the fan type is a double-rotor fan, controlling the speed of the fan according to the first control signal to generate a speed signal comprises: controlling the speed of the first rotor according to the duty cycle of the first control signal and obtaining the actual speed of the first rotor; determining a second control signal based on the actual speed of the first rotor and the duty cycle of the first control signal; controlling the speed of the second rotor according to the second control signal to obtain the actual speed of the second rotor; and determining the speed signal of the fan based on the actual speed of the first rotor and the actual speed of the second rotor; wherein the speed signal of the fan comprises a period and a duty cycle, and determining the speed signal of the fan based on the actual speed of the first rotor and the actual speed of the second rotor comprises: determining the period of the speed signal based on the actual speed of the first rotor; obtaining a ratio of the actual speed of the second rotor to the actual speed of the first rotor; in a case where the ratio is less than or equal to a second preset value, determining the duty cycle of the speed signal based on a product of the ratio and a second preset ratio plus a third preset ratio; and in a case where the ratio is greater than the second preset value, determining the duty cycle of the speed signal based on a product of the ratio and a fourth preset ratio plus a fifth preset ratio, wherein the third preset ratio is less than the fifth preset ratio.

2. The method of claim 1, wherein The second control signal comprises a period and a duty cycle, and determining the second control signal based on the actual speed of the first rotor and the duty cycle of the first control signal comprises: determining the period of the second control signal based on the actual speed of the first rotor; determining the duty cycle of the second control signal based on the duty cycle of the first control signal.

3. The method of claim 2, wherein wherein, the period of the second control signal is determined based on a ratio of a first preset value to the actual speed of the first rotor; the duty cycle of the second control signal is determined based on a sum of half of the duty cycle of the first control signal and a first preset ratio.

4. The method of claim 1, wherein controlling the speed of the second rotor according to the second control signal comprises: determining a target speed of the second rotor based on a product of the duty cycle of the second control signal and a rated speed of the second rotor; controlling the speed of the second rotor based on the duty cycle of the second control signal and the target speed of the second rotor.

5. The method of claim 1, wherein determining the fan type to be a double-rotor fan based on the speed signal of the fan comprises: In a case where the duty cycle of the speed signal is less than or equal to a first preset duty cycle threshold or greater than or equal to a second preset duty cycle threshold, the fan type is determined as the double-rotor fan, wherein the second preset duty cycle threshold is greater than the first preset duty cycle threshold.

6. The method of claim 5, wherein The method further comprises: In a case where the duty cycle of the speed signal is a third preset duty cycle threshold, the fan type is determined as a single-rotor fan, wherein the third preset duty cycle threshold is greater than the first preset duty cycle threshold and less than the second preset duty cycle threshold.

7. The method of claim 1, wherein The first control signal is determined based on the target rotating speed of the fan, comprising: The duty cycle of the first control signal is determined based on a ratio between the target rotating speed of the fan and a rated rotating speed of the fan.

8. A fan control assembly, comprising: Comprising: A first signal line and a second signal line, the first signal line being connected to a signal input end of the fan for transmitting a first control signal to the fan, and the second signal line being connected to a signal output end of the fan for receiving a speed signal of the fan, wherein the controller is configured to In a case where the fan type is determined as the double-rotor fan based on the speed signal of the fan, the actual rotating speed of the first rotor and the actual rotating speed of the second rotor are obtained based on the speed signal; wherein in a case where the fan type is the double-rotor fan, the rotating speed of the fan is regulated based on the first control signal to generate a speed signal, comprising: regulating the rotating speed of the first rotor based on the duty cycle of the first control signal and obtaining the actual rotating speed of the first rotor; determining a second control signal based on the actual rotating speed of the first rotor and the duty cycle of the first control signal; regulating the rotating speed of the second rotor based on the second control signal to obtain the actual rotating speed of the second rotor; determining the speed signal of the fan based on the actual rotating speed of the first rotor and the actual rotating speed of the second rotor; wherein the speed signal of the fan comprises a period and a duty cycle, and the determination of the speed signal of the fan based on the actual rotating speed of the first rotor and the actual rotating speed of the second rotor comprises: determining the period of the speed signal based on the actual rotating speed of the first rotor; obtaining a ratio of the actual rotating speed of the second rotor to the actual rotating speed of the first rotor; in a case where the ratio is less than or equal to a second preset value, determining the duty cycle of the speed signal based on a product of the ratio and a second preset ratio plus a third preset ratio; in a case where the ratio is greater than the second preset value, determining the duty cycle of the speed signal based on a product of the ratio and a fourth preset ratio plus a fifth preset ratio, wherein the third preset ratio is less than the fifth preset ratio.

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