Detection control method of brush motor, controller, system and electrical equipment

Abstract

The invention discloses a detection control method for a brush motor, a controller, a system and electrical equipment, relates to the technical field of motors, and can improve the detection accuracy of the working state of the motor under the condition of not influencing the cost. The detection control method for the brush motor comprises the steps that sampling current is obtained, the sampling current is obtained according to the voltage difference between the two ends of a sampling resistor, and the sampling resistor is arranged in a drive circuit of the brush motor; performing ripple algorithm processing on the sampling current to obtain the ripple amplitude of the working current corresponding to the brush motor; and detecting the working state of the brush motor according to the ripple amplitude of the working current and the numerical value of the working current.

Description

Technical Field

[0001] The present application relates to the technical field of electric motors, and in particular to a detection and control method for a brushed motor, a controller, a brushed motor control system, and an electrical device. Background Art

[0002] At present, there are various speed regulation requirements for brushed DC motors in actual applications. At the same time, there are various abnormal conditions such as motor open circuit and stall during the speed regulation process. Based on the changing actual application scenarios of brushed motors, the common processing scheme is to introduce speed detection devices such as grating sensors or Hall sensors into the system, and perform speed regulation, stall, open circuit abnormal protection and other controls according to the sensor detection results. However, the introduction of sensors will increase costs, and the sensors adapted to different motors or different scenarios are also different, which is easy to further increase costs. There are also some non-sensing detection schemes that use filtered current thresholds to determine stalls and open circuits, but the current threshold determination method is prone to failure of the determination threshold under the influence of the environment or other factors, which affects the accuracy of the motor's working status detection. Summary of the invention

[0003] The detection and control method, controller, system and electrical equipment of the brushed motor provided in the embodiments of the present application can improve the accuracy of the detection of the motor working state without affecting the cost.

[0004] According to a first aspect of an embodiment of the present application, a detection and control method for a brushless motor is provided, comprising: Obtaining a sampling current, wherein the sampling current is obtained according to a voltage difference across a sampling resistor, and the sampling resistor is provided in a driving circuit of a brushed motor; Performing ripple algorithm processing on the sampled current to obtain the ripple amplitude of the working current corresponding to the brushed motor; The working state of the brushed motor is detected according to the ripple amplitude of the working current and the value of the working current.

[0005] In some implementations, detecting the working state of the brushed motor according to the ripple amplitude of the working current and the value of the working current includes: Detecting the working state of the brushed motor according to the magnitude relationship between the ripple amplitude and the ripple steady value of the working current, and according to the magnitude relationship between the value of the working current and the no-load current of the brushed motor; Among them, the current flowing through the inductor of the brushed motor is the inductor current, and the ripple steady value is the ripple amplitude of the inductor current when the brushed motor is in a stalled state.

[0006] In some implementations, detecting the working state of the brushed motor according to the ripple amplitude of the working current and the value of the working current includes: When the ripple amplitude reaches the ripple steady value and the operating current is greater than the no-load current, it is determined that the brushed motor is in a stalled state; When the ripple amplitude reaches the ripple steady value and the integral value of the working current per unit time reaches the no-load current, it is determined that the brushed motor is in an open circuit state.

[0007] In some embodiments, the detection and control method of the brushed motor further includes: Performing ripple algorithm processing on the sampled current to obtain a ripple period of the working current corresponding to the brushed motor; The detecting the working state of the brushed motor according to the ripple amplitude of the working current and the value of the working current comprises: When the ripple amplitude is another valid value other than the non-ripple steady value, and the working current has the ripple period, the ripple period is the rotation speed of the brushed motor.

[0008] In some implementations, obtaining the sampled current includes: Sampling the working current of the brushed motor according to the sampling frequency to obtain the sampled current, and recording the waveform period of the driving waveform; The sampling frequency is set according to the period of the driving waveform of the brushed motor.

[0009] In some implementations, the sampling frequency is the same as the frequency of the driving waveform.

[0010] In some implementations, sampling the operating current of the brushed motor according to a sampling frequency includes: The working current corresponding to each driving waveform is sampled once, and the number of sampling times is the same as the number of cycles of the driving waveform.

[0011] In some implementations, sampling the operating current of the brushed motor includes: The operating current is sampled at a midpoint of the effective duty cycle of the driving waveform to obtain the sampled current.

[0012] In some embodiments, the brushed motor control system includes a controller, the controller is electrically connected to the drive circuit, and the drive circuit is electrically connected to the brushed motor; The performing ripple algorithm processing on the sampled current includes: In the case where the value of the sampling current is less than the minimum current value of the driving waveform, the minimum current value of the driving waveform output by the controller is controlled to be the value of the current sampling current, and the count of the ripple filtering process is cleared; In the case where the value of the sampling current is greater than the maximum current value of the driving waveform, the maximum current value of the driving waveform output by the controller is controlled to be the value of the current sampling current, and the count of the ripple filtering process is cleared; When the count accumulation value of the ripple filtering process is greater than the set count value, the ripple calculation of the sampled current is started to obtain the ripple amplitude and the ripple period.

[0013] In some implementations, in the ripple calculation, the ripple amplitude is the difference between the maximum current value and the minimum current value of the driving waveform.

[0014] In some embodiments, the set count value is 5 and the single count is 1; and / or, The ripple period is the waveform period of the recorded driving waveform.

[0015] According to a second aspect of an embodiment of the present application, a controller is provided, including: A processor and a memory, wherein the memory stores computer program instructions, and the computer program instructions are used by the processor to execute the detection and control method of the brushed motor as described in the first aspect when the processor is running.

[0016] According to a third aspect of the embodiments of the present application, a brushed motor control system is provided, comprising: The controller as described in the second aspect; A driving circuit, comprising a sampling module and a driving module, wherein the sampling module is electrically connected to the controller and the driving module respectively; A brushed motor is electrically connected to the driving circuit.

[0017] In some embodiments, the driving module includes: a half-bridge circuit, a sampling resistor and an energy storage capacitor, wherein the half-bridge circuit is electrically connected to the sampling resistor, the controller, the energy storage capacitor and the brushed motor respectively; The two ends of the sampling resistor are electrically connected to the two input ends of the sampling module respectively.

[0018] According to a fourth aspect of the embodiments of the present application, there is provided an electrical device, including: A brushed motor control system as described in the third aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1A schematic flow chart of a detection and control method for a brushless motor provided in an embodiment of the present application; Figure 2 A schematic structural diagram of a brushed motor control system provided in an embodiment of the present application; Figure 3 A schematic structural diagram of another brushed motor control system provided in an embodiment of the present application; Figure 4 A schematic logic diagram of a ripple calculation process of a sampling current provided in an embodiment of the present application; Figure 5 A schematic structural block diagram of a controller provided in an embodiment of the present application; Figure 6 A schematic structural block diagram of an electrical device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0020] In order to better understand the technical solutions provided by the embodiments of this specification, the technical solutions of the embodiments of this specification are described in detail below through the accompanying drawings and specific embodiments. It should be understood that the embodiments of this specification and the specific features in the embodiments are detailed descriptions of the technical solutions of the embodiments of this specification, rather than limitations on the technical solutions of this specification. In the absence of conflict, the embodiments of this specification and the technical features in the embodiments can be combined with each other.

[0021] At present, there are various speed regulation requirements for brushed DC motors in the actual application process. At the same time, there will be various abnormal states such as motor open circuit and stall during the speed regulation process. Based on the actual application scenarios of brushed motors, the common processing scheme is to introduce speed detection devices such as grating sensors or Hall sensors into the system, and perform speed regulation, stall and open circuit abnormal protection according to the sensor detection results. However, the introduction of sensors will increase costs, and different application scenarios of motors have different requirements for sensors, which will also increase uncontrollable costs; the introduction of sensors also introduces new reliability failure factors. There are also some non-sensing detection schemes that use filtered current thresholds to determine stall and open circuit. The stall current threshold determination method is prone to stall threshold determination failure due to the difference in motor and winding temperature; the open circuit current threshold determination method is prone to threshold determination failure because the motor is in the second quadrant no-load operating condition, and the working current is extremely small. Therefore, the current threshold determination method is prone to threshold determination failure under the influence of the environment or other factors, which affects the accuracy of the motor working state detection.

[0022] In view of this, Figure 1 A schematic flow chart of a detection and control method for a brushed motor provided in an embodiment of the present application. In a first aspect of the present application, a detection and control method for a brushed motor is provided, referring to Figure 1, the detection and control method of the brushed motor may include: S100: Obtaining a sampling current, wherein the sampling current is obtained according to a voltage difference across a sampling resistor, and the sampling resistor is provided in a driving circuit of a brushed motor.

[0023] Figure 2 A schematic structural diagram of a brushed motor control system provided in an embodiment of the present application. For example, refer to Figure 2 The brushed motor control system may include a controller 1, a drive circuit 2 and a brushed motor 3. The controller 1 is used to drive the brushed motor 3 through the drive circuit 2. The controller 1 may output a drive signal to the drive circuit 2. The waveform of the drive signal is a drive waveform. The drive circuit 2 is provided with a sampling resistor. By detecting the voltage difference across the sampling resistor, the voltage difference across the sampling resistor is divided by the resistance value of the sampling resistor to obtain a sampling current. The sampling current may reflect the driving condition of the drive circuit to the brushed motor, and the sampling current may reflect the working state of the brushed motor.

[0024] Exemplarily, the control instruction for acquiring the sampled current may be issued by a control program in the controller 1 .

[0025] S200: performing ripple algorithm processing on the sampled current to obtain the ripple amplitude of the working current corresponding to the brushless motor.

[0026] For example, under the action of the driving waveform, the numerical waveform of the sampling current also has ripple characteristics. By performing ripple algorithm processing on the numerical value of the sampling current, the ripple amplitude of the sampling current can be obtained, and other parameters of ripple characteristics can also be obtained. The ripple parameter of the sampling current can reflect the ripple characteristics of the working current of the brushed motor, that is, the ripple amplitude of the sampling current can be used as the ripple amplitude of the working current. Therefore, by performing ripple algorithm processing on the sampling current, the ripple amplitude of the working current of the brushed motor can be obtained.

[0027] S300: Detecting the working state of the brushed motor according to the ripple amplitude of the working current and the value of the working current.

[0028] Exemplarily, the working state of the brushed motor can be detected by judging the value of the ripple amplitude of the working current and the value of the working current.

[0029] For example, if the working state of a brushed motor is judged solely by the working current value, the working state may be easily misjudged due to the influence of the ambient temperature. For example, at high temperatures, the circuit resistance increases and the working current decreases. In this case, the smaller working current caused by the high temperature may be misjudged as a motor stalled state. For example, at low temperatures, the circuit resistance decreases and the working current increases. In this case, the larger working current caused by the low temperature may be misjudged as a motor open circuit state.

[0030] For example, if the ripple amplitude is used alone to judge the working state of the motor, it is easy to misjudge the working state of the motor due to the influence of different ripple amplitudes caused by different motor models, different driving modes or different driving circuit structures.

[0031] Therefore, the embodiment of the present application judges the value of the working current and the ripple amplitude of the working current by current sampling to realize the detection of the working status of the brushed motor, which can avoid the increase in cost caused by the introduction of sensors, and can also avoid misdetection caused by the use of current thresholds. Through the two numerical analysis methods of ripple amplitude and working current, the working status of the brushed motor can be detected more effectively and accurately, thereby facilitating correct and timely control operations on the brushed motor.

[0032] In some examples, step S300 may include: The working state of the brushed motor is detected according to the relationship between the ripple amplitude and the ripple steady value of the working current, and according to the relationship between the working current value and the no-load current of the brushed motor; wherein, the current flowing through the inductor of the brushed motor is the inductor current, and the ripple steady value is the ripple amplitude of the inductor current in the stalled state of the brushed motor.

[0033] In some examples, the motor will periodically perform carbon brush commutation in the speed regulation project. After each commutation, the current will rise in the new quadrant due to the characteristics of the inductance. For this reason, a current sampling method is proposed to obtain the sampling current of the working current, and the ripple algorithm is performed on the sampling current. The ripple period, ripple amplitude, and real-time value of the working current can be calculated in real time, and necessary filtering can be performed respectively.

[0034] It should be noted that if the driving signal used to drive the motor is an AC signal, the working current should also be an AC waveform, so the sampling current obtained by sampling the working current is also an AC waveform. The current flowing through the inductor of the brushed motor is the inductor current. When the brushed motor is in a stalled state, the inductor current approaches the DC current. The ripple stability value is the ripple amplitude of the inductor current when the brushed motor is in a stalled state. The inductor current can represent the working current of the motor. When the motor is operating normally, the inductor current is also an AC waveform; when the motor is stalled, the inductor current will continue to saturate and change from AC to an effectively stable DC. At this time, the working current has no ripple waveform, and the ripple amplitude of the inductor current at this time is theoretically 0. In different motor types, different environmental scenarios, and different drive circuits, the ripple amplitude of the DC inductor current is not necessarily 0, but can also be other values. The ripple amplitude of the stable DC inductor current is defined as the ripple stability value. According to different motor control systems, the ripple stability value can also be different.

[0035] It should be noted that the no-load current of the motor is the working current of the motor when it is not rotating. Theoretically, the no-load current is 0, but due to factors such as ambient temperature, motor type, and motor drive type, the value of the no-load current may not be 0.

[0036] In some examples, step S300 may include: When the ripple amplitude reaches the ripple steady value and the operating current is greater than the no-load current, it is determined that the brushed motor is in a stalled state.

[0037] For example, during the motor driving process, when the ripple steady value is 0, when the ripple amplitude is close to 0 and the operating current is much larger than the no-load current, it is the judgment condition for the motor to be stalled, because at this time the current flowing through the inductor is an effectively stable DC, that is, the motor has not undergone phase change, so it is judged to be stalled.

[0038] When the ripple amplitude reaches the ripple steady value and the integral value of the working current per unit time reaches the no-load current, it is determined that the brushed motor is in an open circuit state.

[0039] For example, during the motor driving process, when the ripple steady value is 0, when the ripple amplitude is close to 0 and the integral value of the working current is also close to 0, it is the judgment condition that the motor is no-load. Because the open-circuit current is absolutely 0, the integral value is also infinitely close to 0. There is a certain current when it is no-load, and the integral value will not be infinitely close to 0, so it is judged that the motor is open-circuited.

[0040] It should be noted that the closeness mentioned in this embodiment is infinitely close and can be regarded as equal, but due to the influence of some error factors, there may be incomplete equivalence. Therefore, the ripple amplitude of this embodiment is achieved within a certain error range.

[0041] In some embodiments, the detection and control method of the brushed motor may further include: Performing ripple algorithm processing on the sampled current to obtain a ripple period of the working current corresponding to the brushed motor; Step S300 may include: When the ripple amplitude is a valid value other than a non-ripple steady value and the working current has a ripple period, the ripple period is the rotation speed of the brushed motor.

[0042] Exemplarily, other valid values ​​other than the non-ripple steady value represent that the working current is in a non-DC state, that is, the working current has a valid value of the ripple amplitude, and at the same time there is a ripple period. It can be determined that the brushed motor is operating normally, and the ripple period of the working current is the speed of the brushed motor, that is, during the motor driving process, when the ripple amplitude and the ripple period exist at the same time, the ripple period can be regarded as the motor speed.

[0043] Figure 3 A schematic structural diagram of another brushed motor control system provided in an embodiment of the present application. In some embodiments, reference Figure 3 In the brushed motor control system, the driving circuit may include a sampling module 21 and a driving module, and the driving module may include a half-bridge circuit 22, a sampling resistor R and an energy storage capacitor C. The two input ends of the sampling module 21 are connected to the two ends of the sampling resistor R, the output end of the sampling module 21 is connected to the controller 1, the energy storage capacitor is connected between the half-bridge circuit 22 and the sampling resistor R, and the brushed motor 3 is connected to the half-bridge circuit 22. The half-bridge circuit 22 includes 4 transistors, the gates of the 4 transistors are all connected to the controller 1, and the 4 transistors are respectively a first transistor T1, a second transistor T2, a third transistor T3 and a fourth transistor T4, T1 and T3 are connected in series and then connected in parallel with T2 and T4. The sampling resistor R is connected in series with the half-bridge circuit 22, the sampling resistor R is connected in series with the energy storage capacitor C, and the energy storage capacitor C is connected in series with the half-bridge circuit 22. The two ends of the energy storage capacitor C can be used to access the power supply. The two ends of the motor are respectively connected to the series node of T1 and T3 and the series node of T2 and T4.

[0044] Exemplary, reference Figure 3 The controller 1 stores a control program, which can control the controller 1 to output a drive signal, the drive signal has a drive waveform, and the drive signal drives the brushed motor 3 to run through the drive circuit. The sampling module 21 can include an operational amplifier, and the operational amplifier is used to collect the voltage difference across the sampling resistor R, and the current flowing through the sampling resistor can be obtained as the sampling current, which can realize the sampling of the working current. The working current is the current current driving the motor to run, and the waveform of the sampling current can reflect the waveform of the working current.

[0045] In some implementations, step 100 may include: According to the sampling frequency, the working current of the brushed motor is sampled to obtain the sampled current, and the waveform period of the driving waveform is recorded. The sampling frequency is set according to the period of the driving waveform of the brushed motor.

[0046] In some examples, the operating current may be sampled once across multiple cycles of the driving waveform, for example, once every two cycles of the driving waveform, or once every three cycles of the driving waveform.

[0047] In some examples, the sampling frequency may be the same as the frequency of the driving waveform, that is, the working current is sampled as many times as the number of cycles of the driving waveform. The sampling may be once for one cycle of the driving waveform, or may be multiple times within one cycle of the driving waveform, without specific limitation.

[0048] In some examples, sampling the operating current of the brushed motor according to the sampling frequency may include: The working current corresponding to each driving waveform is sampled once, and the number of sampling times is the same as the number of cycles of the driving waveform. That is, the working current corresponding to the driving waveform is sampled wave by wave, which can be regarded as sampling the working current wave by wave.

[0049] In some implementations, sampling the operating current of the brushed motor may include: The operating current is sampled at the midpoint of the effective duty cycle of the driving waveform to obtain the sampled current.

[0050] For example, at the midpoint of the effective duty cycle of the drive waveform, the working current corresponding to the drive waveform tends to be stable. There are instantaneous current fluctuations at the starting point and end point of the effective duty cycle of the drive waveform, which will interfere with the sampling. That is, during the speed regulation process, the motor will periodically perform carbon brush commutation. After each commutation, the current in the quadrant will have a climbing process due to the characteristics of the inductance. Therefore, current sampling at the midpoint of the effective duty cycle of the drive waveform can obtain a more accurate sampling current.

[0051] In some embodiments, the brushed motor control system includes a controller, the controller is electrically connected to the driving circuit, the driving circuit is electrically connected to the brushed motor, and the controller can drive the operation of the brushed motor through the driving circuit.

[0052] Step S200 may include: When the value of the sampling current is less than the minimum current value of the driving waveform, the minimum current value of the driving waveform output by the controller is controlled to be the value of the current sampling current, and the count of the ripple filtering process is cleared.

[0053] For example, when the value of the sampled current is less than the minimum current value of the drive waveform, it can be regarded as sampling following the downward trend of the drive waveform. If the minimum drive waveform value is not collected, it is necessary to continue sampling and control the minimum value of the drive waveform output after the current sampling moment to be set to the value of the current sampled current. At this time, ripple filtering processing can be omitted, and the count of the ripple filtering processing can be clear.

[0054] When the value of the sampling current is greater than the maximum current value of the driving waveform, the maximum current value of the driving waveform output by the controller is controlled to be the value of the current sampling current, and the count of the ripple filtering process is cleared; For example, when the value of the sampled current is greater than the maximum current value of the drive waveform, it can be regarded as sampling following the rising trend of the drive waveform. If the maximum drive waveform value is not collected, it is necessary to continue sampling and control the maximum value of the drive waveform output after the current sampling moment to be set to the value of the current sampled current. At this time, ripple filtering processing can be omitted, and the count of the ripple filtering processing can be clear.

[0055] When the count accumulation value of the ripple filtering process is greater than the set count value, the ripple calculation of the sampled current is started to obtain the ripple amplitude and the ripple period.

[0056] In some examples, in the ripple calculation, the ripple amplitude is the difference between the maximum current value and the minimum current value of the driving waveform.

[0057] Exemplarily, the count value is set to 5, and the single count is 1. The count value may also be set to 2, 3, 4, 6, etc., without specific limitation.

[0058] In some examples, the ripple period is a waveform period of a recorded driving waveform.

[0059] Figure 4 A schematic logic diagram of a ripple calculation process of a sampling current provided in an embodiment of the present application. For example, refer to Figure 4 , the sampling current can be expressed as AdCur, the maximum current value of the driving waveform is expressed as AdMax, the minimum current value of the driving waveform is expressed as AdMin, the count value of the ripple filtering process is expressed as RipFil, the ripple period is expressed as RipPrd, and the ripple amplitude is expressed as RipCur. RipFil is a cumulative count, expressed as RipFil++, a single accumulation of 1, and the set count value corresponding to RipFil is illustrated by taking 5 as an example. Under the initial condition, AdMax=AdCur=0, AdMin=1024. It should be noted that in the process of sampling the working current, the initial condition is set to ensure that AdMax is minimum and AdMin is maximum. In the current sampling process, the value of AdCur is between 0 and 1024. Therefore, when AdCur is less than AdMin, the value of the sampled AdCur is assigned to AdMin; when AdCur is greater than AdMax, the value of the sampled AdCur is assigned to AdMax, so that the obtained sampling current can more accurately represent the ripple of the working current.

[0060] Exemplary, reference Figure 4 The current sampling of the brushed motor and the ripple calculation process of the sampled current may include the following steps: Start current sampling, obtain the sampled current AdCur, and record the waveform period Tn of the obtained drive waveform. It should be noted that Tn is continuously accumulated and recorded, that is, expressed as Tn++, which is the waveform period recorded according to the time axis of the drive waveform.

[0061] The magnitude of the sampling current AdCur and the minimum current value AdMin of the driving waveform is determined.

[0062] When AdMin>AdCur, set AdMin=AdCur and RipFil=0.

[0063] When AdMin≤AdCur, continue to judge the size of the sampling current AdCur and the maximum current value AdMax of the driving waveform.

[0064] When AdMax>AdCur, set AdMax=AdCur and RipFil=0.

[0065] When AdMax≤AdCur, continue to determine the relationship between RipFil++ and 5; When RipFil++>5, the ripple period RipPrd=Tn is set. When Tn++ is large enough, it is confirmed that there is no ripple. Tn=0 represents re-counting. The ripple amplitude RipCur=AdMax-AdMin, that is, the ripple period and ripple amplitude data can be obtained, and the ripple calculation processing of the sampled current is completed.

[0066] When RipFil++≤5, the ripple calculation process ends. Note that AdFil++≤5 continues to wait for the time when AdFil++>5. When Tn++ is large enough, it is confirmed that there is no ripple, and Tn=0.

[0067] The brushed motor detection control method provided in the embodiment of the present application can determine the stall state based on the stall current characteristics of the motor and the transient current ripple characteristics of the DC brushed motor when it is stalled, thereby realizing non-sensing stall detection during the operation of the brushed DC motor; according to the motor no-load and second quadrant working current characteristics, the judgment of the motor open circuit fault is identified based on the transient current integration method, thereby realizing motor open circuit detection; according to the working current characteristics determined by commutation, inductance characteristics, etc., based on signal ripple detection, the detection and identification of the periodic current characteristics of the motor operation is completed, thereby realizing non-sensing estimation of the motor speed.

[0068] According to a second aspect of an embodiment of the present application, a controller is provided, comprising: a processor and a memory, wherein the memory stores computer program instructions, and when the computer program instructions are executed by the processor, the detection and control method of the brushed motor as described in the first aspect is executed.

[0069] Figure 5A schematic structural block diagram of a controller provided in an embodiment of the present application. For example, refer to Figure 5 The controller 1 includes a memory 11 and a processor 12. The processor memory stores computer program instructions. The computer program instructions are used by the processor to execute the detection and control method of the brushed motor as described in the first aspect when the processor is running. The detection and control method of the brushed motor may include the following steps: Obtaining a sampling current, wherein the sampling current is obtained according to a voltage difference across a sampling resistor, and the sampling resistor is provided in a driving circuit of a brushed motor; The sampled current is processed by a ripple algorithm to obtain the ripple amplitude of the working current corresponding to the brushed motor; The working state of the brushed motor is detected according to the ripple amplitude of the working current and the value of the working current.

[0070] According to a third aspect of an embodiment of the present application, a brushed motor control system is provided, comprising: a controller as described in the second aspect; a drive circuit, comprising a sampling module and a drive module, the sampling module being electrically connected to the controller and the drive module respectively; and a brushed motor being electrically connected to the drive circuit.

[0071] Exemplary, reference Figure 2 The brushed motor control system may include a controller 1, a drive circuit 2 and a brushed motor 3. The controller 1 is used to drive the brushed motor 3 through the drive circuit 2. The controller 1 may output a drive signal to the drive circuit 2. The waveform of the drive signal is a drive waveform. The drive circuit 2 is provided with a sampling resistor. By detecting the voltage difference across the sampling resistor, the voltage difference across the sampling resistor is divided by the resistance value of the sampling resistor to obtain a sampling current. The sampling current may reflect the driving condition of the drive circuit to the brushed motor, and the sampling current may reflect the working state of the brushed motor.

[0072] Exemplarily, the detection and control instructions of the motor may be issued by a control program in the controller. The control program may be a computer program stored in a memory.

[0073] In some embodiments, the driving module includes: a half-bridge circuit, a sampling resistor and an energy storage capacitor, the half-bridge circuit is electrically connected to the sampling resistor, the controller, the energy storage capacitor and the brushed motor respectively; the two ends of the sampling resistor are electrically connected to the two input ends of the sampling module respectively.

[0074] In some examples, reference Figure 3In the brushed motor control system, the driving circuit may include a sampling module 21 and a driving module, and the driving module may include a half-bridge circuit 22, a sampling resistor R and an energy storage capacitor C. The two input ends of the sampling module 21 are connected to the two ends of the sampling resistor R, the output end of the sampling module 21 is connected to the controller 1, the energy storage capacitor is connected between the half-bridge circuit 22 and the sampling resistor R, and the brushed motor 3 is connected to the half-bridge circuit 22. The half-bridge circuit 22 includes 4 transistors, the gates of the 4 transistors are all connected to the controller 1, and the 4 transistors are respectively a first transistor T1, a second transistor T2, a third transistor T3 and a fourth transistor T4, T1 and T3 are connected in series and then connected in parallel with T2 and T4. The sampling resistor R is connected in series with the half-bridge circuit 22, the sampling resistor R is connected in series with the energy storage capacitor C, and the energy storage capacitor C is connected in series with the half-bridge circuit 22. The two ends of the energy storage capacitor C can be used to access the power supply. The two ends of the motor are respectively connected to the series node of T1 and T3 and the series node of T2 and T4.

[0075] Exemplary, reference Figure 3 The controller 1 stores a control program, i.e., a computer program. The control program can control the controller 1 to output a drive signal. The drive signal has a drive waveform. The drive signal drives the brushed motor 3 to operate through the drive circuit. The sampling module 21 can include an operational amplifier. The operational amplifier is used to collect the voltage difference across the sampling resistor R. The current flowing through the sampling resistor can be obtained as the sampling current. The sampling of the working current can be realized. The working current is the current current driving the motor to operate. The waveform of the sampling current can reflect the waveform of the working current.

[0076] Figure 6 A schematic structural block diagram of an electrical device provided in an embodiment of the present application. Figure 6 According to a fourth aspect of an embodiment of the present application, an electrical device is provided, including: a brushed motor control system as described in the third aspect.

[0077] Exemplarily, the electrical equipment may be any equipment including a motor, such as household appliances or kitchen appliances such as air conditioners, washing machines, refrigerators, and range hoods, and may also be large mechanical equipment or vehicles.

[0078] In this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of more restrictions, the elements limited by the statement "comprise one..." do not exclude the existence of other identical elements in the process, method, article or equipment including the elements. The term "more than two" includes two or more than two situations.

[0079] The described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0080] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

[0081] Although the preferred embodiments of this specification have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of this specification.

[0082] Obviously, those skilled in the art can make various changes and modifications to this specification without departing from the spirit and scope of this specification. Thus, if these modifications and variations of this specification fall within the scope of the claims of this specification and their equivalents, this specification is also intended to include these modifications and variations.

Claims

1. A detection and control method for a brushed motor, characterized in that: include: Obtaining a sampling current, wherein the sampling current is obtained according to a voltage difference across a sampling resistor, and the sampling resistor is provided in a driving circuit of a brushed motor; Performing ripple algorithm processing on the sampled current to obtain the ripple amplitude of the working current corresponding to the brushed motor; The working state of the brushed motor is detected according to the ripple amplitude of the working current and the value of the working current.

2. The detection and control method of a brushed motor according to claim 1, characterized in that: The detecting the working state of the brushed motor according to the ripple amplitude of the working current and the value of the working current comprises: Detecting the working state of the brushed motor according to the magnitude relationship between the ripple amplitude and the ripple steady value of the working current, and according to the magnitude relationship between the value of the working current and the no-load current of the brushed motor; Among them, the current flowing through the inductor of the brushed motor is the inductor current, and the ripple steady value is the ripple amplitude of the inductor current when the brushed motor is in a stalled state.

3. The detection and control method of a brushed motor according to claim 2, characterized in that: The detecting the working state of the brushed motor according to the ripple amplitude of the working current and the value of the working current comprises: When the ripple amplitude reaches the ripple steady value and the operating current is greater than the no-load current, it is determined that the brushed motor is in a stalled state; When the ripple amplitude reaches the ripple steady value and the integral value of the working current per unit time reaches the no-load current, it is determined that the brushed motor is in an open circuit state.

4. The detection and control method of a brushed motor according to claim 2, characterized in that: Also includes: Performing ripple algorithm processing on the sampled current to obtain a ripple period of the working current corresponding to the brushed motor; The detecting the working state of the brushed motor according to the ripple amplitude of the working current and the value of the working current comprises: When the ripple amplitude is another valid value other than the non-ripple steady value, and the working current has the ripple period, the ripple period is the rotation speed of the brushed motor.

5. The detection and control method of a brushed motor according to claim 1, characterized in that: The obtaining of the sampled current comprises: Sampling the working current of the brushed motor according to the sampling frequency to obtain the sampled current, and recording the waveform period of the driving waveform; Wherein, the sampling frequency is set according to the period of the driving waveform of the brushed motor.

6. The detection and control method of a brushed motor according to claim 5, characterized in that: The sampling frequency is the same as the frequency of the driving waveform.

7. The detection and control method of a brushed motor according to claim 5, characterized in that: The step of sampling the working current of the brushed motor according to the sampling frequency includes: The working current corresponding to each driving waveform is sampled once, and the number of sampling times is the same as the number of cycles of the driving waveform.

8. The detection and control method of a brushed motor according to claim 5, characterized in that: The sampling of the working current of the brushed motor includes: The operating current is sampled at a midpoint of the effective duty cycle of the driving waveform to obtain the sampled current.

9. The detection and control method of a brushed motor according to any one of claims 1 to 8, characterized in that: The brushed motor control system includes a controller, the controller is electrically connected to the drive circuit, and the drive circuit is electrically connected to the brushed motor; The performing ripple algorithm processing on the sampled current includes: In the case where the value of the sampling current is less than the minimum current value of the driving waveform, the minimum current value of the driving waveform output by the controller is controlled to be the value of the current sampling current, and the count of the ripple filtering process is cleared; In the case where the value of the sampling current is greater than the maximum current value of the driving waveform, the maximum current value of the driving waveform output by the controller is controlled to be the value of the current sampling current, and the count of the ripple filtering process is cleared; When the count accumulation value of the ripple filtering process is greater than the set count value, the ripple calculation of the sampled current is started to obtain the ripple amplitude and the ripple period.

10. The detection and control method of a brushed motor according to claim 9, characterized in that: In the ripple calculation, the ripple amplitude is the difference between the maximum current value and the minimum current value of the driving waveform.

11. The detection and control method of a brushed motor according to claim 9, characterized in that: The set count value is 5, and the single count is 1; and / or, The ripple period is the waveform period of the recorded driving waveform.

12. A controller, characterized in that: include: A processor and a memory, wherein the memory stores computer program instructions, and the computer program instructions are used by the processor to execute the detection and control method of the brushed motor according to any one of claims 1 to 11 when the processor is running.

13. A brushed motor control system, characterized in that: include: The controller as claimed in claim 12; A driving circuit, comprising a sampling module and a driving module, wherein the sampling module is electrically connected to the controller and the driving module respectively; A brushed motor is electrically connected to the driving circuit.

14. The brushed motor control system according to claim 13, characterized in that: The driving module comprises: a half-bridge circuit, a sampling resistor and an energy storage capacitor, wherein the half-bridge circuit is electrically connected to the sampling resistor, the controller, the energy storage capacitor and the brushed motor respectively; Two ends of the sampling resistor are electrically connected to two input ends of the sampling module respectively.

15. An electrical device, characterized in that: include: A brushed motor control system as claimed in claim 13.

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