Brush direct current motor control method, device, equipment and medium

Abstract

The embodiment of the invention discloses a brush direct current motor control method and device, equipment and a medium. The brush direct current motor control method comprises the following steps: determining the partial voltage of the brush direct current motor; detecting the real-time current of the brush direct current motor; the induced electromotive force is calculated based on the voltage division law by adopting the divided voltage, the real-time current and the impedance characteristic of the brush direct current motor; calculating the real-time rotating speed of the brush direct current motor by adopting the induced electromotive force based on the law of electromagnetic induction; and under the condition that the real-time rotating speed of the brush direct current motor is smaller than a rotating speed threshold value, determining that the brush direct current motor is in a locked-rotor working condition. According to the method for judging whether the brush direct current motor is locked or not, a Hall sensor does not need to be arranged, a connecting pin used for being connected with the Hall sensor and a corresponding signal processing circuit do not need to be arranged in a circuit board used for data processing, the limited surface area of the circuit board is saved, and the utilization rate of the circuit board is improved.

Description

Technical Field

[0001] The present disclosure relates to the field of motor control technology, and in particular to a brushed DC motor control method, device, equipment and medium. Background Art

[0002] Due to the advantages of simple structure and low cost, brushed DC motors are widely used as the power source for vehicle seats, windows and tailgate controls. Since the output power of brushed DC motors is not high, when the load is too large or the load is blocked by obstacles, brushed DC motors may run in a stalled condition during operation. In a stalled condition, brushed DC motors will generate a lot of heat; due to their poor heat dissipation, excessive heat generated by stalling will cause their functions to fail.

[0003] In order to prevent the brushed DC motor from malfunctioning due to excessive heat generation during stalling, it is necessary to detect the operating speed of the brushed DC motor and identify whether it is running in a stalled condition based on the speed. When it is determined that the brushed DC motor is running in a stalled condition, the power supply is stopped to prevent it from continuing to generate heat during the stalled condition. Among them, detecting the operating speed of the brushed DC motor is a prerequisite for determining whether it is running in a stalled condition and then determining whether to stop powering it.

[0004] In the related art, a Hall sensor is set in the brushed DC motor, and the Hall sensor outputs a speed detection signal, which is processed by the body control module (BCM) to determine the operating speed of the brushed DC motor. In order to process the speed signal output by the Hall sensor, the body control module needs to be provided with a connection pin for receiving the speed detection signal and a processing circuit for processing the speed detection signal. When a large number of brushed DC motors are configured, it is necessary to set connection pins and processing circuits for each Hall sensor, resulting in serious consumption of the connection pins and surface area of ​​the body control circuit board. Summary of the invention

[0005] In order to solve the above technical problems or at least partially solve the above technical problems, the present application provides a brushed DC motor control method, device, equipment and storage medium.

[0006] In a first aspect, the present application provides a brushed DC motor control method, the method comprising:

[0007] Determining a divided voltage of the brushed DC motor;

[0008] Detecting the real-time current of the brushed DC motor;

[0009] Calculating the induced electromotive force based on the voltage division law using the divided voltage, the real-time current and the impedance characteristics of the brushed DC motor;

[0010] Based on the law of electromagnetic induction, the real-time speed of the brushed DC motor is calculated using the induced electromotive force;

[0011] When the real-time rotation speed of the brushed DC motor is less than a rotation speed threshold, it is determined that the brushed DC motor is in a stalled condition.

[0012] Optionally, determining the divided voltage of the brushed DC motor includes:

[0013] Acquire a power supply voltage for supplying power to the brushed DC motor and a shutdown duty cycle of a shutdown control circuit for controlling the brushed DC motor;

[0014] A pulse width modulation algorithm is adopted to calculate the divided voltage according to the power supply voltage and the shutdown duty cycle.

[0015] Optionally, the method of using the divided voltage, the real-time current and the impedance characteristic of the brushed DC motor to calculate the induced electromotive force based on the voltage division law further includes:

[0016] Determining the equivalent resistance and equivalent inductance of the brushed DC motor;

[0017] Calculating a non-inductive divided voltage according to the real-time current, the equivalent resistance and the equivalent inductance;

[0018] The induced electromotive force is obtained by subtracting the non-inductive divided voltage from the divided voltage.

[0019] Optionally, the method of calculating the real-time rotation speed of the brushed DC motor by using the induced electromotive force based on the law of electromagnetic induction further includes:

[0020] Obtaining the electromotive force constant and magnetic flux per pole of the brushed DC motor;

[0021] The real-time rotational speed is calculated based on a functional relationship among the induced electromotive force, the electromotive force constant, the magnetic flux per pole and the real-time rotational speed.

[0022] Optionally, the method further includes: when it is determined that the motor is in a stalled rotor condition, stopping supplying power to the brushed DC motor.

[0023] In a second aspect, the present application provides a brushless DC stand-alone control device, comprising:

[0024] The divided voltage acquisition unit is used to determine the divided voltage of the brushed DC motor;

[0025] The real-time current acquisition unit is used to detect the real-time current of the brushed DC motor;

[0026] The induced electromotive force acquisition unit is used to calculate the induced electromotive force based on the voltage division law by using the divided voltage, the real-time current and the impedance characteristics of the brushed DC motor;

[0027] The real-time speed acquisition unit is used to calculate the real-time speed of the brushed DC motor using the induced electromotive force based on the law of electromagnetic induction;

[0028] The stall judgment unit is used to determine that the brushed DC motor is in a stall condition when the real-time rotation speed of the brushed DC motor is less than a rotation speed threshold.

[0029] Optionally, the real-time speed acquisition unit includes a parameter acquisition subunit, which is used to acquire the electromotive force constant and the magnetic flux per pole of the brushed DC motor;

[0030] The real-time speed calculation subunit is used to calculate the real-time speed according to the functional relationship among the induced electromotive force, the electromotive force constant, the magnetic flux per pole and the real-time speed.

[0031] Optionally, the present application provides a brushless DC single machine control device, further comprising:

[0032] The control unit is used to stop supplying power to the brushed DC motor when it is determined that the motor is in a stalled rotor condition.

[0033] In a third aspect, the present application provides a control device, including a processor and a memory, wherein the memory is used to store a computer program; when the computer program is loaded by the processor, the processor executes the control method of the brushed DC motor as described above.

[0034] In a fourth aspect, the present application provides a computer-readable storage medium, wherein the storage medium stores a computer program. When the computer program is executed by a processor, the processor implements the control method of the brushed DC motor as described above.

[0035] The solution provided by the embodiment of the present disclosure, after determining the divided voltage of the brushed DC motor and detecting the real-time current of the brushed DC motor, calculates the induced electromotive force according to the divided voltage and the real-time current, and calculates the real-time speed of the brushed DC motor according to the induced electromotive force; finally, determines whether it is in a stalled condition according to the real-time speed of the brushed DC motor. The method for determining whether a brushed DC motor is stalled in the embodiment of the present disclosure does not require the provision of a Hall sensor, nor does it require the provision of a connection pin for connecting a Hall sensor and a corresponding signal processing circuit in a circuit board for data processing, thereby saving the limited surface area of ​​the circuit board and improving the utilization rate of the circuit board. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0037] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0038] Figure 1 This is a flow chart of a brushed DC motor control method according to an embodiment of the present disclosure;

[0039] Figure 2 A control circuit diagram of a brushed DC motor according to an embodiment of the present disclosure;

[0040] Figure 3 The internal equivalent circuit diagram of the DC motor described in the embodiment of the present disclosure;

[0041] Figure 4 A diagram of a brushed DC motor control device according to an embodiment of the present disclosure;

[0042] Figure 5 A schematic diagram of the structure of a control device provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0043] In order to more clearly understand the above-mentioned objectives, features and advantages of the present disclosure, the scheme of the present disclosure will be further described below. It should be noted that the embodiments of the present disclosure and the features in the embodiments can be combined with each other without conflict.

[0044] In the following description, many specific details are set forth to facilitate a full understanding of the present disclosure, but the present disclosure may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present disclosure, rather than all of the embodiments.

[0045] Before introducing a brushed DC motor control method provided in an embodiment of the present application, the classification of motors and motor stalling are first introduced to facilitate understanding of the present solution.

[0046] A motor is an electromagnetic device that converts or transmits electrical energy based on the law of electromagnetic induction. When the motor is powered on, it generates a driving torque and drives the load to do work. Motors are divided into DC motors and AC motors according to the power supply used.

[0047] Among them, DC motors can be divided into brushless DC motors and brushed DC motors according to whether they are equipped with common brushes and commutators.

[0048] The brushless DC motor consists of a motor body and a driver. Since the brushless DC motor operates in an automatic control mode, it does not require an additional starting winding on the rotor like a synchronous motor that starts under heavy load under variable frequency speed regulation, nor does it produce oscillation and loss of step when the load changes suddenly. However, its performance is mainly determined by the electronic speed regulator. A good electronic speed regulator requires overall control of processes such as single-chip control program design, circuit design, and complex processing technology. Therefore, its price is much higher than that of a brushed motor. It may also have disadvantages such as poor starting and stopping braking effect and small starting torque.

[0049] The brushed DC motor mainly includes a stator, a rotor and a brush. The coil obtains a torque by rotating in a magnetic field, thereby outputting kinetic energy. The brush and the commutator are in contact with each other, and the commutator can be rotated to conduct electricity and commutate. Therefore, the disadvantages of the brushed DC motor are as follows: due to the large friction between the brush and the commutator, the loss is also large; due to the large contact resistance between the brush and the commutator, the overall resistance of the motor is large, which is easy to heat up, affecting the life of the brushed DC motor; due to the problem of easy heating, the output power of the brushed DC motor is not large, and the working efficiency is also reduced. However, the brushed DC motor has a simple structure, is easy to use, and has a lower cost than the brushless DC motor, so it is widely used in scenarios where cost control is more sensitive and the application frequency is lower.

[0050] The control method provided in the embodiment of the present application is mainly for brushed DC motors. Brushed DC motors have good speed control capabilities, stable speed, and are compact and light, so they are suitable for vehicle seats, windows, and tailgate controls as power sources.

[0051] Brushed DC motors often stall when they are working. Motor stalling is a phenomenon in which the motor still outputs torque when the speed is 0 rpm. It is a phenomenon in which the motor cannot start and rotate due to excessive load, mechanical failure of the drag, bearing damage and bore sweeping. When the motor is stalled, the power factor is extremely low, and the current can reach several times the rated current, which will burn the motor over a long period of time. In order to avoid the heat generated by stalling and burning the motor, a method should be designed to detect the working condition of the motor in real time, so as to quickly confirm whether the motor is in a stalled condition and confirm that the motor is powered off in time when it is in a stalled condition. At this stage, the most commonly used method is to achieve real-time monitoring of the motor speed through Hall detection.

[0052] In order to connect and receive the detection signal sent by the Hall sensor, a connection pin for connecting the Hall sensor needs to be provided on the circuit board, and a corresponding signal processing circuit also needs to be provided, resulting in a large amount of limited circuit board surface being occupied.

[0053] The present application provides a brushed DC motor control method, which improves the motor drive circuit so as to detect whether the brushed DC motor is in a stalled condition without using a Hall sensor.

[0054] Figure 1 Figure 1 is a flow chart of a brushed DC motor control method. Figure 1 As shown, a brushed DC motor control method provided by an embodiment of the present disclosure includes S101-S105.

[0055] The control method of the brushed DC motor provided in the embodiment of the present disclosure can be executed by a control device, which is equipped with circuits and software for controlling the start, stop and speed of the DC motor.

[0056] S101: Determine the divided voltage of the brushed DC motor.

[0057] In a specific implementation, a brushed DC motor, a shutdown control circuit and a power supply are connected in series, and a control device can obtain the power supply voltage and the shutdown duty cycle of the shutdown control circuit; and then calculate the divided voltage according to the power supply voltage and the shutdown duty cycle.

[0058] S102: Detect the real-time current of the brushed DC motor.

[0059] In a specific implementation, the real-time current of the brushed DC motor can be detected by a current sensor arranged in the circuit.

[0060] S103: Calculate the induced electromotive force based on the voltage division law using the divided voltage, the real-time current and the impedance characteristics of the brushed DC motor.

[0061] In a specific implementation, before the control device calculates the induced electromotive force based on the divided voltage and real-time current, it first determines the equivalent resistance and equivalent inductance of the brushed DC motor; then, based on Kirchhoff's voltage-dividing law, it uses the divided voltage, real-time current, equivalent resistance and equivalent inductance to calculate the induced electromotive force.

[0062] S104: Based on the law of electromagnetic induction, the real-time speed of the brushed DC motor is calculated using the induced electromotive force.

[0063] In order to determine the real-time speed of the DC motor, the control device first obtains the electromotive force constant and the magnetic flux per pole of the brushed DC motor, and then calculates the real-time speed of the brushed DC motor based on the law of electromagnetic induction using the induced electromotive force, the electromotive force constant and the magnetic flux per pole. In the implementation of the present disclosure, the control device pre-stores the electromotive force constant and the magnetic flux per pole of the brushed DC motor of the corresponding model.

[0064] S105: When the real-time rotation speed of the brushed DC motor is less than the rotation speed threshold, it is determined that the brushed DC motor is in a stalled condition.

[0065] In the disclosed embodiment, the control device can compare the real-time speed of the motor with a preset speed threshold to determine whether the brushed DC motor is in a stalled condition. If the real-time speed of the motor is greater than the speed threshold, it means that the motor is not in a stalled condition; if the real-time speed of the motor is less than the speed threshold, it means that the motor is in a stalled condition.

[0066] By adopting the solution provided in the above-mentioned embodiment of the present application, by improving the software and hardware design of the motor drive system, using software to calculate the real-time speed of the motor has the advantages of simplicity, flexibility, easy implementation, and reliable performance. There is no need to set up an additional Hall signal judgment circuit, which saves circuit board area and connection pins, saves costs, and improves the utilization rate of the circuit board.

[0067] In some embodiments of the present disclosure, after executing S105, if it is determined that the brushed DC motor is in a stalled condition, the following steps may also be executed.

[0068] If the result of the determination is that the motor is in a stalled condition, the control device stops supplying power to the brushed DC motor in order to protect the motor.

[0069] Of course, if it is determined that the motor is not in a stalled condition, the brushed DC motor will continue to be powered to ensure normal operation of the motor.

[0070] Figure 2 The control circuit diagram of a brushed DC motor includes a motor controller 201, four MOS tubes and a signal amplifier 202.

[0071] The motor controller 201 is installed in the body control circuit board (BCM). The external control signal is transmitted to the body control circuit board; the motor controller 201 controls the rotation of the motor, including the control of the forward and reverse rotation of the motor; the four MOS tubes are connected to the motor controller, and the motor controller 201 controls the working state of the four MOS tubes 2, thereby controlling the opening and closing of the motor and the speed control; the signal amplifier 202 is used to amplify the current signal and send it to the motor controller, so that the motor controller can calculate the real-time speed of the motor based on the current.

[0072] exist Figure 2 In the circuit topology diagram of a brushed DC motor control method shown in the circuit diagram, the on / off and speed of the brushed DC motor are controlled by setting a DC motor drive circuit. The DC motor drive circuit in the embodiment disclosed in the present application adopts an H-bridge construction method. The H-bridge is a typical DC motor control circuit.

[0073] In order to control both the speed and the direction of rotation of the DC motor, the present embodiment uses an H-bridge type to construct a DC motor drive circuit. The construction method of the H-bridge type drive circuit is as follows: Figure 2 In the circuit topology diagram of a brushed DC motor control method shown in FIG, a four-way switch is set to supply power to the two input terminals of the DC motor, which can provide both a forward voltage and a reverse voltage to the DC motor, thereby controlling the forward and reverse rotation of the DC motor.

[0074] The H-bridge DC motor drive circuit used in the embodiment of the present application uses MOS tubes as switches, and four MOS tubes are required to control the voltages of the two input terminals of the motor. When MOS tubes S1 and S4 are turned on, MOS tubes S2 and S3 are turned off at the same time, and the current flows out from the power supply, flows from the left end of the motor to the right end of the motor, and then flows back to the negative pole, that is, the grounding point, so that the motor rotates in one direction, and it can be considered that the motor is in a forward rotation state; when MOS tubes S2 and S3 are turned on, MOS tubes S1 and S4 are turned off at the same time, and the current flows out from the power supply, flows from the right end of the motor to the left end of the motor, and then flows back to the negative pole, that is, the grounding point, and the motor rotates in another direction, and it can be considered that the motor is in a reverse rotation state. When driving the motor, it is also very important to ensure that the two MOS tubes on the same side of the bridge are not turned on at the same time. If MOS tubes S1 and S2 are turned on at the same time, the current will go from the positive pole of the power supply through the two MOS tubes directly back to the negative pole. At this time, there is no other load in the circuit except the MOS tube, so the current in the circuit reaches the maximum value, burning the MOS tube and the power supply. The same principle applies to S3 and S4 being turned on at the same time.

[0075] The H-bridge DC motor driving circuit in the embodiment of the present application adjusts the DC motor speed by controlling the MOS tube duty cycle. The larger the MOS tube duty cycle, the larger the average voltage and average current passing through the DC motor, and the faster the DC motor rotates; the smaller the MOS tube duty cycle, the smaller the average voltage and average current passing through the DC motor, and the slower the DC motor rotates. In this way, the rotation speed of the DC motor can be controlled.

[0076] Here, the above-mentioned MOS tube and MOS tube duty cycle are introduced. The full name of MOS tube is metal oxide semiconductor field effect transistor. MOS tube is a voltage-controlled current device. Generally, in the circuit, it usually plays an amplifying and switching role. Therefore, the advantages of using MOS tube to control the DC motor in the embodiment of the present application are: the input impedance of the MOS tube is high, and it can be driven by a small voltage, and it has a high sensitivity; the speed of opening and closing of the MOS tube is also fast, and it is easier to control the DC motor. The MOS tube duty cycle value is the ratio of the time that the MOS tube is turned on to the entire cycle. The duty cycle of the MOS tube determines the voltage, current and power that it can output. A high duty cycle can increase the output power, and a low duty cycle can reduce the output power. In practical applications, the duty cycle can be adjusted according to the power demand of the DC motor.

[0077] The embodiment of the present application calculates the motor speed by improving the internal design of the motor, and then analyzes whether the motor is blocked by the speed. The method is simple and easy to implement, and the detection result is more accurate through the above-mentioned simple circuit connection. Compared with the previous improvement, the Hall sensor is required to detect the working condition of the motor, which is more convenient, simple and accurate. The embodiment of the present application does not need to set up a Hall signal acquisition circuit, thereby greatly reducing the use of circuit boards, increasing the utilization rate of circuit boards, and reducing costs.

[0078] As analyzed above, the embodiment of the present application can obtain the power supply voltage and the shutdown duty cycle of the shutdown control circuit, and calculate the divided voltage according to the power supply voltage and the shutdown duty cycle.

[0079] Specifically, the motor is mainly controlled by the motor drive circuit on the microprocessor unit, which can control the speed and direction of the motor by controlling the voltage and current. The MOS tube of the motor drive circuit added to the microprocessor unit is used to control the start and stop of the motor; when the motor drive circuit on the microprocessor unit outputs a control signal, the MOS tube will conduct the current and the motor will start to rotate; when the motor control chip stops outputting the control signal, the MOS tube will disconnect the current and the motor will stop rotating. Therefore, the duty cycle of the MOS tube that can shut down the control circuit should be collected first, and then the motor voltage divider voltage is calculated by the power supply voltage and the shutdown duty cycle. In the embodiment of the present disclosure, a MOS tube duty cycle monitoring device is set in the circuit board. After the MOS tube duty cycle information is obtained in real time through the duty cycle monitoring device, the control device can calculate the real-time voltage applied to both sides of the brushed DC motor using formula 1.

[0080] V m =V BAT ×D formula 1

[0081] Where Vm is the motor divided voltage; VBAT is the power supply voltage; D is the MOS tube shutdown duty cycle.

[0082] As analyzed above, the embodiment of the present application needs to determine the equivalent resistance and equivalent inductance of the brushed DC motor.

[0083] Because the equivalent resistance and the equivalent inductance are both fixed property values ​​of the DC motor, the values ​​of the equivalent resistance and the equivalent inductance can be stored in a memory and read from the memory when needed.

[0084] The real-time current of the DC motor can be obtained through a current sensor.

[0085] Figure 3is the internal equivalent circuit diagram of the DC motor. According to Kirchhoff's voltage law, the sum of the voltage rise in a closed loop is equal to the sum of the voltage drop. Therefore, the motor voltage divider in the DC motor is equal to the sum of the equivalent resistance voltage, the equivalent inductance voltage, and the induced electromotive force. From this, the motor induced electromotive force can be calculated. Therefore, after calculating the non-inductive voltage divider based on the real-time current, equivalent resistance and equivalent inductance, the induced electromotive force can be obtained by subtracting the non-inductive voltage divider from the voltage divider. The specific process is shown in Formula 2.

[0086]

[0087] Where Vm is the motor divided voltage, E is the induced electromotive force, i is the real-time current, R is the equivalent resistance, and L is the equivalent inductance;

[0088] As analyzed above, the control device in the embodiment of the present disclosure obtains the electromotive force constant and the magnetic flux per pole of the brushed DC motor, and then calculates the real-time rotation speed of the brushed DC motor according to the induced electromotive force.

[0089] In the specific implementation, according to the law of electromagnetic induction, the motor speed is calculated according to the induced electromotive force, the electromotive force constant, and the magnetic flux per pole. The specific process is shown in Formula 3:

[0090] E=CeΦnFormula 3

[0091] Where E is the induced electromotive force, Ce is the electromotive force constant, Φ is the magnetic flux per pole, and n is the motor speed.

[0092] The electromotive force constant is calculated by formula 4:

[0093] Ce=PN / 60a Formula 4

[0094] Where P is the number of pole pairs, N is the total number of turns of the armature winding, and a is the number of branch pairs in the armature winding.

[0095] The embodiment of the present application proposes to stop supplying power to the brushed DC motor when it is determined that the motor is in a stalled rotor condition.

[0096] Specifically, the motor is judged whether it is stalled according to the preset speed threshold. When the speed reaches the threshold, the MOS tube keeps the current on; when the speed does not reach the threshold, it means that the motor is stalled, and the program will disconnect the current of the MOS tube to stop the motor from working in order to protect the motor.

[0097] The embodiment of the present application also provides a brushed DC stand-alone control device. Figure 4 Figure 2 is a diagram of a brushed DC motor control device. Figure 4As shown, the brushed DC stand-alone control device includes a divided voltage acquisition unit 401 , a real-time current acquisition unit 402 , an induced electromotive force acquisition unit 403 , a real-time rotation speed acquisition unit 404 and a stall determination unit 405 .

[0098] The divided voltage acquisition unit 401 determines the divided voltage of the brushed DC motor, acquires the power supply voltage and the shutdown duty cycle of the shutdown control circuit, and calculates the divided voltage according to the power supply voltage and the shutdown duty cycle.

[0099] The real-time current acquisition unit 402 detects the real-time current of the brushed DC motor. After passing through the sampling resistor, it is amplified by the signal amplifier and input into the microprocessor unit, thereby calculating the real-time current of the motor.

[0100] The induced electromotive force acquisition unit 403 uses the divided voltage, real-time current and impedance characteristics of the brushed DC motor to calculate the induced electromotive force based on the voltage division law. Before calculating the induced electromotive force based on the divided voltage and real-time current, the equivalent resistance and equivalent inductance of the brushed DC motor should be determined first; then based on Kirchhoff's voltage law, the divided voltage, real-time current, equivalent resistance and equivalent inductance are used to calculate the induced electromotive force.

[0101] The real-time speed acquisition unit 404 calculates the real-time speed of the brushed DC motor using the induced electromotive force based on the electromagnetic induction law. The electromotive force constant and the magnetic flux per pole of the brushed DC motor are first obtained, and then the real-time speed of the brushed DC motor is calculated using the induced electromotive force based on the electromagnetic induction law. Therefore, the real-time speed should be calculated based on the induced electromotive force, the electromotive force constant and the magnetic flux per pole.

[0102] The stall judgment unit 405 is used to determine that the brushed DC motor is in a stall condition when the real-time speed of the brushed DC motor is less than the speed threshold. The real-time speed of the motor is compared with a speed threshold set in advance. If the real-time speed of the motor is greater than the speed threshold, it means that the motor is not in a stall condition; if the real-time speed of the motor is less than the speed threshold, it means that the motor is in a stall condition.

[0103] In some embodiments, the real-time speed acquisition unit includes: a parameter acquisition subunit and a real-time speed calculation subunit. The parameter acquisition subunit is used to obtain the electromotive force constant and the magnetic flux per pole of the brushed DC motor, and then transmit the information to the real-time speed acquisition unit to calculate the real-time speed. The real-time speed calculation subunit is used to calculate the real-time speed according to the functional relationship between the induced electromotive force, the electromotive force constant, the magnetic flux per pole and the real-time speed.

[0104] In some embodiments, a control unit is further included. If the stall determination unit 405 determines that the DC motor is in a stall condition, the control unit stops supplying power to the brushed DC motor.

[0105] An embodiment of the present disclosure further provides a control device, which includes a processor and a memory, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, any of the above embodiments can be implemented.

[0106] Figure 5 Schematic diagram of the structure of the control device provided by the embodiment of the present disclosure. Figure 5 , which shows a structural schematic diagram of a control device suitable for implementing the embodiments of the present disclosure. Figure 5 The control device shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present disclosure.

[0107] like Figure 5 As shown, the control device may include a processing device 501 (e.g., a central processing unit, a graphics processing unit, etc.), which can perform various appropriate actions and processes according to a program stored in a read-only memory ROM 502 or a program loaded from a storage device 508 to a random access memory RAM 503. Various programs and data required for the operation of the control device are also stored in RAM 503. The processing device 501, ROM 502, and RAM 503 are connected to each other via a bus 504. In addition, an I / O interface 505, an input device 506, and an output device 507 are also connected to the bus 504.

[0108] In particular, according to an embodiment of the present disclosure, the process described above with reference to the flowchart can be implemented as a computer software program. For example, an embodiment of the present disclosure includes a computer program product, which includes a computer program carried on a non-transitory computer-readable medium, and the computer program contains program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from a network through a communication device 509, or installed from a storage device 508, or installed from a ROM 502. When the computer program is executed by the processing device 501, the above-mentioned functions defined in the method of the embodiment of the present disclosure are executed.

[0109] It should be noted that the computer-readable medium disclosed above may be a computer-readable signal medium or a computer-readable storage medium or any combination of the above two. The computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present disclosure, a computer-readable storage medium may be any tangible medium containing or storing a program that may be used by or in combination with an instruction execution system, device or device. In the present disclosure, a computer-readable signal medium may include a data signal propagated in a baseband or as part of a carrier wave, in which a computer-readable program code is carried. This propagated data signal may take a variety of forms, including but not limited to an electromagnetic signal, an optical signal, or any suitable combination of the above. The computer readable signal medium may also be any computer readable medium other than a computer readable storage medium, which may send, propagate or transmit a program for use by or in conjunction with an instruction execution system, apparatus or device. The program code contained on the computer readable medium may be transmitted using any suitable medium, including but not limited to: wires, optical cables, RF (radio frequency), etc., or any suitable combination of the above.

[0110] In some embodiments, the client and the server may communicate using any currently known or future developed network protocol such as HTTP (HyperText Transfer Protocol), and may be interconnected with any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include a local area network ("LAN"), a wide area network ("WAN"), an internet (e.g., the Internet), and a peer-to-peer network (e.g., an ad hoc peer-to-peer network), as well as any currently known or future developed network.

[0111] The computer-readable medium may be included in the control device, or may exist independently without being assembled into the control device.

[0112] The above description is only a specific embodiment of the present disclosure, so that those skilled in the art can understand or implement the present disclosure. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure will not be limited to the embodiments described herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A brushed DC motor control method, characterized in that: include: Determining a divided voltage of the brushed DC motor; Detecting the real-time current of the brushed DC motor; Calculating the induced electromotive force based on the voltage division law using the divided voltage, the real-time current and the impedance characteristics of the brushed DC motor; Based on the law of electromagnetic induction, the real-time speed of the brushed DC motor is calculated using the induced electromotive force; When the real-time rotation speed of the brushed DC motor is less than a rotation speed threshold, it is determined that the brushed DC motor is in a stalled condition.

2. The method according to claim 1, characterized in that Determining the divided voltage of the brushed DC motor includes: Acquire a power supply voltage for supplying power to the brushed DC motor and a shutdown duty cycle of a shutdown control circuit for controlling the brushed DC motor; The divided voltage is calculated according to the power supply voltage and the off duty cycle using a pulse width modulation algorithm.

3. The method according to claim 1, characterized in that The method of calculating the induced electromotive force based on the voltage division law by using the divided voltage, the real-time current and the impedance characteristic of the brushed DC motor further includes: Determining the equivalent resistance and equivalent inductance of the brushed DC motor; Calculating a non-inductive divided voltage according to the real-time current, the equivalent resistance and the equivalent inductance; The induced electromotive force is obtained by subtracting the non-inductive divided voltage from the divided voltage.

4. The method according to claim 1, characterized in that The method of calculating the real-time speed of the brushed DC motor by using the induced electromotive force based on the law of electromagnetic induction also includes: Obtaining the electromotive force constant and magnetic flux per pole of the brushed DC motor; The real-time rotational speed is calculated based on a functional relationship among the induced electromotive force, the electromotive force constant, the magnetic flux per pole and the real-time rotational speed.

5. The method according to claim 1, characterized in that Also includes: When it is determined that the motor is in a stalled rotor condition, power supply to the brushed DC motor is stopped.

6. A brushed DC motor control device, characterized in that: include: A divided voltage acquisition unit, used to determine the divided voltage of the brushed DC motor; A real-time current acquisition unit, used to detect the real-time current of the brushed DC motor; An induced electromotive force acquisition unit, configured to calculate the induced electromotive force based on the voltage division law by using the divided voltage, the real-time current and the impedance characteristic of the brushed DC motor; A real-time speed acquisition unit, used to calculate the real-time speed of the brushed DC motor using the induced electromotive force based on the law of electromagnetic induction; The stall judgment unit is used to determine that the brushed DC motor is in a stall condition when the real-time rotation speed of the brushed DC motor is less than a rotation speed threshold.

7. The device according to claim 6, characterized in that The real-time speed acquisition unit includes: A parameter acquisition subunit, used to acquire the electromotive force constant and the magnetic flux per pole of the brushed DC motor; The real-time speed calculation subunit is used to calculate the real-time speed according to the functional relationship among the induced electromotive force, the electromotive force constant, the magnetic flux per pole and the real-time speed.

8. The device according to claim 6, characterized in that Also includes: The control unit is used to stop supplying power to the brushed DC motor when it is determined that the motor is in a stalled rotor condition.

9. A control device, comprising a processor and a memory, wherein the memory is used to store a computer program; when the computer program is loaded by the processor, the processor executes the control method of the brushed DC motor according to any one of claims 1 to 5.

10. A computer-readable storage medium, characterized in that: The storage medium stores a computer program, and when the computer program is executed by the processor, the processor implements the control method of the brushed DC motor as described in claims 1-5.

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