An intelligent braking method for a brushless motor

Abstract

The invention discloses an intelligent braking method for a brushless motor, which is based on an intelligent braking system for a brushless motor. The system comprises a power supply module, a switch module, a motor drive module, a main control MCU, a voltage detection module, a temperature detection module, and a current detection module. The control method comprises the following steps: the main control MCU detects the three-phase reaction electromotive force of the brushless motor through P, thereby calculating the rotation speed of the motor at that time, and driving the DEIVER to operate the brushless motor through D. If the brushless motor needs to be braked at a rotation speed of X, the controller will delay for a Y time, during which no energy is provided, so that the brushless motor can operate by inertia. The rotation speed X of the brushless motor during operation is received by the MCU, so as to intelligently judge the working situation at that time, and then, according to different rotation speeds, different Y delay times are performed on the brushless motor, which is safe, reliable, and has a good user experience.

Description

Technical Field

[0001] The invention relates to the technical field of brushless motor control, and in particular to an intelligent braking method for a brushless motor. Background Art

[0002] In recent years, society has developed rapidly, and the technology of brushless motors has gradually matured. The brushed DC motors that previously dominated electric drive devices relied on mechanical converters and brushes for commutation, which was particularly prone to wear. The motor structure was also relatively complex, and the operating stability was poor. Now brushless DC motors are used in many industries. They have the advantages of brushed DC motors, no mechanical commutation device, long service life, high safety, and low maintenance costs. However, the braking methods of the current brushless DC motor controllers are mainly divided into braking with energy recovery and direct locking braking without energy recovery. With energy recovery, the battery pack will be charged unintentionally, which may cause certain unexpected damage to the battery pack. Without energy recovery, the direct locking brake has a greater impact on the structure, motor and controller electronic components, greatly reducing the life of the motor and components, and the vibration and abnormal noise caused by the immediate locking of the machine do not give the user a good experience. Summary of the invention

[0003] The present invention provides an intelligent braking method for a brushless motor, which can solve the problem that the existing brushless controller controls the braking method of the brushless motor, which causes a large impact on the motor and the electronic components of the controller and causes a poor user experience.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] An intelligent braking method for a brushless motor is based on an intelligent braking system, wherein the intelligent braking system includes a power supply module, a switch module, a motor drive module, a main control MCU, a voltage detection module, a temperature detection module, and a current detection module; wherein:

[0006] The power supply module is connected to the temperature detection module.

[0007] The switch module is respectively connected to the voltage detection module, the motor drive module, and the NC1 pin of the main control MCU;

[0008] The voltage detection module is connected to the Vsen pin and the BV pin of the main control MCU respectively.

[0009] The motor drive module is connected to the current detection module and the D pin and the P pin of the main control MCU respectively.

[0010] The temperature detection module is connected to the BS pin and the PT1 pin of the main control MCU respectively;

[0011] The current detection module is connected to the Isen pin of the main control MCU;

[0012] The control method includes the main control MCU detecting the three-phase reaction electromotive force of the brushless motor through P, thereby calculating the motor speed at that time, and using D to drive DEIVER to operate the brushless motor;

[0013] Assuming that the brushless motor needs to be braked at a speed of X, the controller will delay for Y time, during which time no energy is provided, allowing the brushless motor to operate by inertia; the MCU receives the speed X of the brushless motor during operation to intelligently judge the current working conditions, and then delays the brushless motor for different Y times according to different speeds, and then brakes.

[0014] Further, the switch module includes a P+ port, a TP+ port, a ST- port, a BS+ port, a first switch SW1, a second switch SW2, a resistor R1, a resistor R2, and a diode D1;

[0015] The positive electrode of the upper battery pack is connected to the P+ port,

[0016] The P+ port is connected to the TP+ port, the voltage detection module, and the motor drive module respectively.

[0017] The TP+ port is connected to the first switch SW1 and the second switch SW2 respectively;

[0018] The first switch SW1 is connected to the anode of the diode D1 through the ST-port;

[0019] The cathode of the diode D1 is connected to the voltage detection module;

[0020] The second switch SW2 is connected to one end of the resistor R1 through the BS+ port;

[0021] The other end of the resistor R1 is connected to the ground GND through the resistor R2;

[0022] The other end of the resistor R1 is connected to the NC1 pin of the main control MCU.

[0023] Further, the voltage detection module includes a third switch SW3, a diode D2, a resistor R10, a resistor R11, a resistor R12, a resistor R13, and a power conversion module;

[0024] One end of the third switch SW3 is connected to the P+ port,

[0025] The first path of the other end of the third switch SW3 is connected to the cathode of the diode D2.

[0026] The anode of the diode D2 is connected to the cathode of the diode D1,

[0027] The second path at the other end of the third switch SW3 is connected to the power source VCC through the power conversion module.

[0028] The third path at the other end of the third switch SW3 is connected to one end of the resistor R12.

[0029] The other end of resistor R12 is connected to the BV pin of the main control MCU.

[0030] Another path of the other end of the resistor R12 is connected to the ground GND through the resistor R13.

[0031] Furthermore, the temperature detection module includes a PT1 port,

[0032] PT1 of Battery1 pack is connected to one end of resistor R4.

[0033] The other end of the resistor R4 is connected to the ground GND through the resistor R5.

[0034] The other end of the resistor R1 is connected to the PT1 pin of the main control MCU.

[0035] Furthermore, the current detection module includes an operational amplifier U1, a resistor R9, and a resistor R3.

[0036] The inverting input terminal of the operational amplifier U1 is connected to the motor drive module.

[0037] Another path of the inverting input terminal of the operational amplifier U1 is connected to the ground GND through the resistor R9.

[0038] The output end of the operational amplifier U1 is connected to the Isen pin of the main control MCU.

[0039] Another path of the output terminal of the operational amplifier U1 is connected to the non-inverting input terminal of the operational amplifier U1 through the resistor R3.

[0040] Furthermore, the control method comprises the following specific steps:

[0041] (1) Startup:

[0042] Press the controller switch to start the operation. During this process, the MCU detects whether the battery pack power supply voltage is normal through the voltage detection module; the current detection module detects whether the controller current is too large; the temperature detection module detects whether the battery pack temperature is normal; the above detections are normal and abnormal, and the MCU flags are given respectively. When the voltage, temperature, and current are all normal flags, the next step of motor operation is carried out; otherwise, the controller buzzes and alarms, and the motor does not run;

[0043] (2) Motor operation:

[0044] When the motor is running, the voltage, current and temperature detection are still continuously performed. When each abnormal flag position is 1, the motor is shut down. The motor three-phase reaction electromotive force is detected through the motor drive module, and the motor speed at that time is calculated based on the reaction electromotive force data.

[0045] (3) Data Detection

[0046] Detect the current speed of the motor, the current of the controller, and the voltage of the battery pack; detect data in real time to perform intelligent braking;

[0047] (4) Release the switch

[0048] The operator releases the switch to brake; during the braking process, press the switch again to stop braking and the motor starts running again.

[0049] 8. The intelligent braking method of a brushless motor according to claim 7, characterized in that:

[0050] The control method further comprises the following steps:

[0051] (5) The speed is lower than the safe speed

[0052] The operator releases the switch and compares the detected motor speed with the set safety speed to determine whether the motor speed is within the safe forced locking braking range.

[0053] (6) Intelligent braking

[0054] When the motor speed is higher than the safe speed, intelligent braking is performed; according to the motor speed, controller current and battery pack voltage at that time; the PWM opening degree of the lower bridge MOS is controlled, and the upper bridge MOS is fully closed for braking; the greater the PWM opening degree of the lower bridge MOS, the greater the motor braking degree; the smaller the PWM opening degree of the lower bridge MOS, the smaller the motor braking degree; the higher the speed of the detected motor, the smaller the PWM opening degree; the higher the current of the detected controller, the smaller the PWM opening degree; the lower the battery pack voltage, the smaller the PWM opening degree; through the data curves of voltage, current and speed at that time, the appropriate PWM opening degree of the lower bridge MOS is given.

[0055] Furthermore, the control method further comprises the following steps:

[0056] (7) Locking brake

[0057] When it is detected that the speed is lower than the set safe speed, the lower bridge MOS is fully opened, that is, the PWM opening degree is adjusted to the maximum, and the upper bridge MOS is fully closed, and the controller will lock the motor and perform forced braking; the motor starts running at a low speed, and then the switch is released, without entering the intelligent braking operation, and the locking brake is directly performed, and the motor speed drops sharply until it stops;

[0058] Through intelligent braking, data detection is performed, and the PWM opening degree of the lower bridge MOS is adjusted again according to the data at that time. Multiple data detections are performed. After the intelligent braking operation, locking braking is performed, and the motor speed drops relatively slowly until it reaches a safe speed. At this time, the motor speed drops sharply until it stops.

[0059] It can be seen from the above technical scheme that the intelligent braking method of the brushless motor of the present invention monitors the speed of the brushless motor after the switch is released, and intelligently controls the brushless controller to perform intelligent braking on the brushless motor, thereby effectively solving the problems of poor user experience and great damage to motors and electronic components in the brushless motor braking solutions on the market. It is safe, reliable, and provides good user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 is a system block diagram of the intelligent braking circuit of the present invention,

[0061] Figure 2 It is a flow chart of the method of the present invention. DETAILED DESCRIPTION

[0062] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0063] like Figure 1 As shown, the intelligent braking method of the brushless motor described in this embodiment is based on an intelligent braking circuit system, including a power supply module 1, a switch module 2, a motor drive module 4, and a main control MCU, and also includes a voltage detection module 3, a temperature detection module 5, and a current detection module 6. The power supply module 1 is connected to the temperature detection module 5, and the switch module 2 is respectively connected to the voltage detection module 3, the motor drive module 4, and the NC1 pin of the main control MCU, the voltage detection module 3 is respectively connected to the Vsen pin and the BV pin of the main control MCU, and the motor drive module 4 is respectively connected to the current detection module 6 and the D pin and the P pin of the main control MCU; the temperature detection module 5 is respectively connected to the BS pin and the PT1 pin of the main control MCU. The current detection module 6 is connected to the Isen pin of the main control MCU.

[0064] Specifically:

[0065] The switch module 2 includes a P+ port, a TP+ port, a ST- port, a BS+ port, a first switch SW1, a second switch SW2, a resistor R1, a resistor R2, and a diode D1.

[0066] The positive electrode of the upper battery pack 11 is connected to the P+ port, the P+ port is respectively connected to the TP+ port, the voltage detection module 3, and the motor drive module 4, the TP+ port is respectively connected to the first switch SW1 and the second switch SW2, the first switch SW1 is connected to the anode of the diode D1 through the ST- port, and the cathode of the diode D1 is connected to the voltage detection module 3.

[0067] The second switch SW2 is connected to one end of the resistor R1 through the BS+ port, the other end of the resistor R1 is connected to the ground GND through the resistor R2, and the other end of the resistor R1 is connected to the NC1 pin of the main control MCU.

[0068] The voltage detection module 3 includes a third switch SW3, a diode D2, a resistor R10, a resistor R11, a resistor R12, a resistor R13, and a power conversion module, wherein one end of the third switch SW3 is connected to the P+ port, a first path of the other end of the third switch SW3 is connected to the cathode of the diode D2, an anode of the diode D2 is connected to the cathode of the diode D1, a second path of the other end of the third switch SW3 is connected to the power supply VCC through the power conversion module, a third path of the other end of the third switch SW3 is connected to one end of the resistor R12, one path of the other end of the resistor R12 is connected to the BV pin of the main control MCU, and another path of the other end of the resistor R12 is connected to the ground GND through the resistor R13.

[0069] The temperature detection module 5 includes a PT1 port, the PT1 of the Battery1 pack is connected to one end of the resistor R4, the other end of the resistor R4 is connected to the ground GND through the resistor R5, and the other end of the resistor R1 is connected to the PT1 pin of the main control MCU.

[0070] The current detection module 6 includes an operational amplifier U1, a resistor R9, and a resistor R3.

[0071] One inverting input terminal of the operational amplifier U1 is connected to the motor drive module 4, and the other inverting input terminal of the operational amplifier U1 is connected to the ground GND through a resistor R9. One output terminal of the operational amplifier U1 is connected to the Isen pin of the main control MCU, and the other output terminal of the operational amplifier U1 is connected to the non-inverting input terminal of the operational amplifier U1 through a resistor R3.

[0072] The following are the specific control steps of the embodiment of the present invention:

[0073] (1) Startup:

[0074] Press the controller switch to start the operation. During this process, the MCU detects whether the battery pack power supply voltage is normal through the voltage detection module. The current detection module detects whether the controller current is too large. The temperature detection module detects whether the battery pack temperature is normal. The above detections will give the MCU flags for normal and abnormal conditions respectively. When the voltage, temperature, and current all get normal flags, the next step is to run the motor. Otherwise, the controller will sound an alarm and the motor will not run.

[0075] (2) Motor operation:

[0076] When the motor is running, the voltage, current and temperature detection are still continuously performed, and the motor will be shut down when each abnormal flag position is 1. The motor drive module detects the three-phase reaction electromotive force of the motor, and the motor speed at that time is calculated based on the reaction electromotive force data.

[0077] (3) Data Detection

[0078] The current speed of the motor, the current of the controller, and the voltage of the battery pack are detected. Real-time detection data is used for intelligent braking.

[0079] (4) Release the switch

[0080] The operator releases the switch to brake. During the braking process, the operator presses the switch again to stop braking and the motor starts running again.

[0081] (5) The speed is lower than the safe speed

[0082] The operator releases the switch and compares the detected motor speed with the set safe speed. It determines whether the motor speed is within the safe forced locking braking range. Forced locking braking will generate a large current shock and the battery pack voltage will be greatly reduced. The parts of the machine will generate a large hard force, which will cause great damage to the battery pack, controller and machine.

[0083] (6) Intelligent braking

[0084] At that time, the motor speed was higher than the safe speed, and intelligent braking was required. According to the motor speed, controller current and battery pack voltage at that time, the PWM opening degree of the lower bridge MOS was controlled, and the upper bridge MOS was fully closed for braking. The greater the PWM opening degree of the lower bridge MOS, the greater the motor braking degree. The smaller the PWM opening degree of the lower bridge MOS, the smaller the motor braking degree. The greater the speed of the detection motor, the smaller the PWM opening degree. The greater the current of the detection controller, the smaller the PWM opening degree. The lower the battery pack voltage, the smaller the PWM opening degree. Through the data curves of voltage, current and speed at that time, the appropriate PWM opening degree of the lower bridge MOS is given.

[0085] (7) Locking brake

[0086] When it is detected that the speed is lower than the set safe speed, the lower bridge MOS is fully opened (PWM opening degree is adjusted to the maximum), and the upper bridge MOS is fully closed, and the controller will lock the motor and perform forced braking. The motor runs at a low speed at the beginning, and then the switch is released. The intelligent braking operation is not entered, and the locking brake is directly performed. The motor speed drops sharply until it stops.

[0087] Through (6) intelligent braking, and then (4) data detection, according to the current data, the PWM opening degree of the lower bridge MOS is adjusted again. After multiple (4) data detections and (6) intelligent braking operations, the locking brake is performed. The motor speed drops relatively slowly until it reaches the safe speed, and then the motor speed drops sharply until it stops.

[0088] Combination Figure 1 and Figure 2 It can be seen that the main control MCU detects the three-phase reaction electromotive force of the brushless motor through P, thereby calculating the motor's speed at that time, and uses D to drive DEIVER to operate the brushless motor. Assuming that the brushless motor needs to be braked at a speed of X, the controller will delay for Y time. During this time, no energy is provided, allowing the brushless motor to operate through inertia. Since the braking energy = the kinetic energy of the motion system, the system kinetic energy will drop rapidly over time due to the effects of friction resistance and air resistance, and then electronic braking will be performed, which will greatly reduce the damage to electronic components and motors. The MCU receives the speed X of the brushless motor during operation to intelligently judge the working conditions at that time, and then performs different Y delay times on the brushless motor according to different speeds, and then brakes. Because of this delay time, the motor speed is reduced to a reasonable value, and then the reverse impact caused by braking is greatly reduced, and the machine will not produce violent vibrations and abnormal noises due to immediate locking, thereby reducing damage to electronic components and motors and greatly enhancing the user experience.

[0089] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. 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 invention.

Claims

1. An intelligent braking method for a brushless motor, based on an intelligent braking system for a brushless motor, the intelligent braking system comprising a power supply module (1), a switch module (2), a motor drive module (4), and a main control MCU, characterized in that: It also includes a voltage detection module (3), a temperature detection module (5), and a current detection module (6); wherein: The power supply module (1) is connected to the temperature detection module (5). The switch module (2) is respectively connected to the voltage detection module (3), the motor drive module (4), and the NC1 pin of the main control MCU; The voltage detection module (3) is connected to the Vsen pin and the BV pin of the main control MCU respectively. The motor drive module (4) is connected to the current detection module (6) and the D pin and the P pin of the main control MCU respectively. The temperature detection module (5) is connected to the BS pin and the PT1 pin of the main control MCU respectively; The current detection module (6) is connected to the Isen pin of the main control MCU; The control method includes the main control MCU detecting the three-phase reaction electromotive force of the brushless motor through the P pin, thereby calculating the motor speed at that time, and using the D pin to drive the motor drive module (4) to operate the brushless motor; Assuming that the brushless motor needs to be braked at a speed of X, the controller will delay for Y time, during which time no energy is provided, allowing the brushless motor to operate by inertia; the MCU receives the speed X of the brushless motor during operation to intelligently judge the working conditions at the time, and then delays the brushless motor for different Y times according to different speeds, and then brakes; The control method further comprises: The operator releases the switch and compares the detected motor speed with the set safe speed to determine whether the motor speed is within the safe forced locking braking range. When the motor speed is higher than the safe speed, intelligent braking is performed; according to the motor speed, controller current and battery pack voltage at that time; the PWM opening degree of the lower bridge MOS is controlled, and the upper bridge MOS is fully closed for braking; the greater the PWM opening degree of the lower bridge MOS, the greater the motor braking degree; the smaller the PWM opening degree of the lower bridge MOS, the smaller the motor braking degree; the greater the speed of the detected motor, the smaller the PWM opening degree; the greater the current of the detected controller, the smaller the PWM opening degree; the lower the battery pack voltage, the smaller the PWM opening degree; through the data curves of voltage, current and speed at that time, the appropriate PWM opening degree of the lower bridge MOS is given; When it is detected that the speed is lower than the set safe speed, the lower bridge MOS is fully opened, that is, the PWM opening degree is adjusted to the maximum, and the upper bridge MOS is fully closed, and the controller will lock the motor and perform forced braking; the motor starts running at a low speed, and then the switch is released, without entering the intelligent braking operation, and the locking brake is directly performed, and the motor speed drops sharply until it stops; Through intelligent braking, data detection is performed, and the PWM opening degree of the lower bridge MOS is adjusted again according to the data at that time. Multiple data detections are performed. After the intelligent braking operation, locking braking is performed, and the motor speed decreases relatively slowly until it reaches a safe speed. The motor speed then drops sharply until it stops.

2. The intelligent braking method of a brushless motor according to claim 1, characterized in that: The switch module (2) comprises a P+ port, a TP+ port, an ST- port, a BS+ port, a first switch SW1, a second switch SW2, a resistor R1, a resistor R2, and a diode D1; The positive electrode of the upper battery pack (11) is connected to the P+ port. The P+ port is connected to the TP+ port, the voltage detection module (3), and the motor drive module (4) respectively. The TP+ port is connected to the first switch SW1 and the second switch SW2 respectively; The first switch SW1 is connected to the anode of the diode D1 through the ST-port; The cathode of the diode D1 is connected to the voltage detection module (3); The second switch SW2 is connected to one end of the resistor R1 through the BS+ port; The other end of the resistor R1 is connected to the ground GND through the resistor R2; The other end of the resistor R1 is connected to the NC1 pin of the main control MCU.

3. The intelligent braking method of a brushless motor according to claim 2, characterized in that: The voltage detection module (3) comprises a third switch SW3, a diode D2, a resistor R10, a resistor R11, a resistor R12, a resistor R13, and a power conversion module; One end of the third switch SW3 is connected to the P+ port, The first path of the other end of the third switch SW3 is connected to the cathode of the diode D2. The anode of the diode D2 is connected to the cathode of the diode D1. The second path at the other end of the third switch SW3 is connected to the power source VCC through the power conversion module. The third path at the other end of the third switch SW3 is connected to one end of the resistor R12. The other end of resistor R12 is connected to the BV pin of the main control MCU. Another path of the other end of the resistor R12 is connected to the ground GND through the resistor R13.

4. The intelligent braking method of a brushless motor according to claim 3, characterized in that: The temperature detection module (5) comprises a PT1 port, Connect PT1 of Battery1 pack to one end of resistor R4. The other end of the resistor R4 is connected to the ground GND through the resistor R5. The other end of the resistor R4 is connected to the PT1 pin of the main control MCU.

5. The intelligent braking method of a brushless motor according to claim 4, characterized in that: The current detection module (6) comprises an operational amplifier U1, a resistor R9, and a resistor R3. The inverting input terminal of the operational amplifier U1 is connected to the motor drive module (4). Another path of the inverting input terminal of the operational amplifier U1 is connected to the ground GND through the resistor R9. The output end of the operational amplifier U1 is connected to the Isen pin of the main control MCU. Another path of the output terminal of the operational amplifier U1 is connected to the non-inverting input terminal of the operational amplifier U1 through the resistor R3.

6. The intelligent braking method of a brushless motor according to claim 1, characterized in that: The specific steps of the control method are as follows: (1) Startup: Press the controller switch to start the operation. During this process, the MCU detects whether the battery pack supply voltage is normal through the voltage detection module; the current detection module detects whether the controller current is too large; The temperature detection module detects whether the battery pack temperature is normal. If the above detection is normal or abnormal, the MCU will be marked. When the voltage, temperature and current are all normal, the next step is to run the motor. Otherwise, the controller will sound an alarm and the motor will not run. (2) Motor operation: When the motor is running, the voltage, current and temperature detection are still continuously performed. When each abnormal flag position is 1, the motor is shut down. The motor three-phase reaction electromotive force is detected through the motor drive module, and the motor speed at that time is calculated based on the reaction electromotive force data. (3) Data detection Detect the current speed of the motor, the current of the controller, and the voltage of the battery pack; detect data in real time to perform intelligent braking; (4) Release the switch The operator releases the switch to brake; during the braking process, press the switch again to stop braking and the motor starts running again.

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