A method and system for detecting forward and reverse rotation of a brushless DC motor

Abstract

The invention discloses a forward and reverse detection method and system for a brushless DC motor, comprising the following steps: S1, establishing a circuit connection: a power module is connected to a brushless controller, and the brushless controller is electrically connected to a brushless motor; a forward and reverse detection device is connected to a brushless controller; S2, a three-phase voltage obtained by voltage division by a voltage division module is used as a positive input voltage of a comparator; S3, a combination signal is formed by combining the output values ​​of the comparator, and a plurality of combination signals are stored in a register according to a time sequence to form a detection sequence; a commutation table is stored in a detection module in the forward and reverse detection device, and the commutation table has a predetermined sequence formed by a plurality of predetermined combination signals; S4, a detection module obtains a detection sequence in a register and compares it with a predetermined sequence in a commutation table to determine the forward and reverse rotation of the motor. The scheme significantly improves the defect detection rate of the brushless DC motor.

Description

Technical Field

[0001] The present invention relates to the technical field of motor state detection, and in particular to a method and system for detecting forward and reverse rotation of a brushless direct current motor. Background Art

[0002] Brushless DC motors are widely used in drive and servo systems. In many cases, the motor is not only required to have good starting and scheduling characteristics, but also to be able to rotate forward and reverse. During the factory inspection of brushless motors, how to efficiently inspect the brushless motors, reduce the outflow of defective products, improve product accuracy, reduce defective output, and reduce customer complaints has always been a key issue that companies need to solve. Summary of the invention

[0003] The purpose of the present invention is to provide a method and system for detecting forward and reverse rotation of a brushless DC motor, which detects the voltage signal of the three-phase line ABC (UVW) and determines whether the motor is rotating forward or reverse by the sequence of the voltage signals before and after commutation (by querying a commutation table); and determines whether the brushless controller is missing a phase by determining whether the current is continuous.

[0004] In order to achieve the above technical purpose, the present invention provides a technical solution, which is a method for detecting forward and reverse rotation of a brushless DC motor, comprising the following steps:

[0005] S1. Establish circuit connection: connect the power module to the brushless controller, and the brushless controller to the brushless motor; connect the forward and reverse detection device to the brushless controller; and connect the voltage divider module to the output end of the brushless controller;

[0006] S2, the three-phase voltage obtained by the voltage division module is used as the positive input voltage of the comparator;

[0007] S3, a combination signal formed by combining the output values ​​of the comparator, and a plurality of combination signals are stored in a register in a detection sequence according to a time sequence; a commutation table is stored in a detection module in the forward and reverse detection device, and the commutation table has a predetermined sequence formed by a plurality of predetermined combination signals;

[0008] S4. The detection module obtains the detection sequence in the register and compares it with the predetermined sequence in the commutation table to determine the forward and reverse rotation of the motor.

[0009] Preferably, in step S3, the eight combination signals output by the comparator and the eight predetermined combination signals in the commutation table are: 111 / 110 / 101 / 100 / 011 / 010 / 001 / 000 respectively; the eight detection sequences are stored in the register bit by bit.

[0010] Preferably, a commutation table is stored in the detection module, and a predetermined sequence is stored in the commutation table. The predetermined sequence includes a forward state value and a reverse state value corresponding to the detection sequence result.

[0011] Preferably, the forward state value corresponding to the detection sequence is expressed as follows:

[0012] The forward state value 001 corresponds to the detection sequence result 011; the forward state value 010 corresponds to the detection sequence 110; the forward state value 011 corresponds to the detection sequence 010; the forward state value 100 corresponds to the detection sequence 101; the forward state value 101 corresponds to the detection sequence 001; the forward state value 110 corresponds to the detection sequence 100.

[0013] Preferably, the inversion state value corresponding to the detection sequence is expressed as follows:

[0014] The inversion state value 001 corresponds to the detection sequence 101; the inversion state value 010 corresponds to the detection sequence 011; the inversion state value 011 corresponds to the detection sequence 001; the inversion state value 100 corresponds to the detection sequence 110; the inversion state value 101 corresponds to the detection sequence 100; and the inversion state value 110 corresponds to the detection sequence 010.

[0015] Preferably, when the combined signal is 111 or 000, it is a fault state and the forward and reverse detection device alarms.

[0016] A DC brushless motor forward and reverse detection system includes a power module, a brushless controller electrically connected to the power module, and a brushless motor electrically connected to the brushless controller; a forward and reverse detection device is connected in parallel to the three-phase output of the brushless controller, and the forward and reverse detection device includes a voltage divider module, the voltage divided by the voltage divider module is used as the positive input voltage of the comparator, the output end of the comparator is electrically connected to the information collection end of the forward and reverse detection device, and the collected combined signal is stored in the corresponding storage bit of the register to form a detection sequence. The center point voltage is used as the negative input of the comparator, and the comparator performs a switching action by comparing the positive and negative input signals, and the comparator output signal is read through the corresponding register in the MCU and compared with a predetermined sequence.

[0017] Preferably, the detection system further comprises a voltage conversion module, which is connected to the three-phase output terminal of the brushless controller to convert the three-phase electricity into a supply voltage for the forward and reverse rotation detection device.

[0018] In this solution, the forward and reverse detection device does not require an additional power supply, and can generate electricity through the controller under test to power the forward and reverse detection device.

[0019] Preferably, the forward and reverse rotation detection device includes a detection module (MUC chip) and a register, the detection module stores a commutation table, and the commutation table stores forward rotation state values ​​and reverse rotation state values ​​corresponding to the detection sequence; the register stores a combination signal at the output end of the comparator, the detection module sequentially obtains the motor state result in the register and compares it with the state result in the commutation table, reads the comparator output signal through the corresponding register in the MCU, and compares it with the predetermined sequence to determine the forward and reverse rotation of the motor.

[0020] Beneficial effects of the present invention: A method and system for detecting forward and reverse rotation of a brushless DC motor of the present invention detects voltage signals of three-phase lines by setting a comparator, and determines whether the motor is rotating forward or reversely by the sequence of voltage signals before and after commutation, which is efficient and fast; determines whether the brushless controller is missing a phase by determining whether the current is continuous; and significantly improves the defect detection rate of the brushless DC motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The present invention is a flow chart of a method for detecting forward and reverse rotation of a brushless DC motor.

[0022] Figure 2 The present invention is a schematic structural diagram of a DC brushless motor forward and reverse rotation detection system.

[0023] Figure 3 It is a circuit principle diagram of the voltage divider module circuit of the present invention.

[0024] Markings in the figure: 1-power module, 2-brushless controller, 3-brushless motor, 4-voltage divider module, 5-forward and reverse detection device, 6-comparator, 7-voltage conversion module. DETAILED DESCRIPTION

[0025] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific implementation method described herein is only an optimal embodiment of the present invention, which is only used to explain the present invention and does not limit the scope of protection of the present invention. All other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0026] Example: Figure 2As shown, a structural schematic diagram of a DC brushless motor forward and reverse detection system is composed of a power module 1, a brushless controller 2 electrically connected to the power module, and a brushless motor 3 electrically connected to the brushless controller; the three-phase output end of the brushless controller is connected to a voltage divider module 4 and a forward and reverse detection device 5, the voltage divided by the voltage divider module is used as the positive input voltage of a comparator 6, the output end of the comparator is electrically connected to the information collection end of the forward and reverse detection device, and the collected combined signal is stored in the corresponding storage bit of the register to form a detection sequence; the detection system also includes a voltage conversion module, the voltage conversion module is connected to the three-phase output end of the brushless controller to convert the three-phase electricity into the power supply voltage of the forward and reverse detection device, the forward and reverse detection device does not need an additional power supply, and can generate electricity through the controller under test to power the forward and reverse detection device. The forward and reverse rotation detection device includes a detection module (MUC chip) and a register. The detection module stores a commutation table, and the commutation table stores forward rotation state values ​​and reverse rotation state values ​​corresponding to the detection sequence; the register stores a combination signal at the output end of the comparator. The detection module sequentially obtains the motor state results in the register and compares them with the state results in the commutation table, reads the comparator output signal through the corresponding register in the MCU, and compares it with the predetermined sequence to determine the forward and reverse rotation of the motor.

[0027] like Figure 3The figure shows the circuit schematic diagram of the voltage divider module. The three-phase line voltages U, V, and W are divided to HA, HB, and HC through voltage divider resistors R36, R37, R38, R48, R49, and R50; STR is the center point, where the voltage is the average value of HA, HB, and HC. The STR terminal is the common negative input of the first comparator, the second comparator, and the third comparator. HA is the positive input of the first comparator 1, HB is the positive input of the second comparator, and HC is the positive input of the third comparator 3. The comparator output combination signal is stored in the register (the comparator output value FHC / FHB / FHA has 8 combination signals, namely 111 / 110 / 101 / 100 / 011 / 010 / 001 / 000). The detection module reads the comparator output value in the register. The combination signal of 111,000 is a fault state. If these two states are read and exceed the preset time, such as 50ms, an error is directly reported. If the other 6 states other than these two states are read, it is correct and the value is attached to the variable hall_status. The comparator output value in the register is read again. And attach the value to the variable hall1, and then compare it with the commutation table to determine whether the motor is forward or reverse, and attach the value of hall1 to hall_status and repeat the cycle, that is, hall_status is the status value of the previous commutation, hall1 is the status value of the current commutation, and the forward and reverse rotation are determined by judging the order of the status values ​​before and after the two times in the corresponding table. If it is forward, a forward signal is given to the user, and if it is reverse, a reverse signal is given to the user; that is, the voltage signal of the three-phase line UVW (ABC) is detected, and the sequence of the voltage signals before and after the commutation is used to determine whether the motor is forward or reverse.

[0028] like Figure 1 As shown, a flow chart of a method for detecting forward and reverse rotation of a brushless DC motor includes the following steps:

[0029] S1. Establish circuit connection: connect the power module to the brushless controller, the brushless controller to the brushless motor; connect the forward and reverse detection device to the brushless controller;

[0030] S2, the three-phase voltage obtained by the voltage division module is used as the positive input voltage of the comparator;

[0031] S3, a combination signal formed by combining the output values ​​of the comparator, and a plurality of combination signals are stored in a register in a detection sequence according to a time sequence; a commutation table is stored in a detection module in the forward and reverse detection device, and the commutation table has a predetermined sequence formed by a plurality of predetermined combination signals;

[0032] S4. The detection module obtains the detection sequence in the register and compares it with the predetermined sequence in the commutation table to determine the forward and reverse rotation of the motor.

[0033] As a specific implementation method, the commutation order of the brushless controller output voltage is UAB / U AC / U BC / U BA / U CA / U CB or U AB / U CB / U CA / U BA / U BC / U AC .

[0034] In step S3, the eight combination signals output by the comparator and the eight predetermined combination signals in the commutation table are: 111 / 110 / 101 / 100 / 011 / 010 / 001 / 000; the eight detection sequences are stored in the register bit by bit. When the combination signal is 111 or 000, it is a fault state, and the forward and reverse detection device alarms.

[0035] The detection module stores a commutation table, in which a predetermined sequence is stored. The predetermined sequence includes a forward state value and a reverse state value corresponding to the detection sequence result.

[0036] The detection sequence includes variables hall_status and hall1, which respectively store the status values ​​of the comparator outputs twice before and after, wherein hall_status stores the status value of the first comparator output, and hall1 stores the status value of the second comparator output; the acquired detection sequence is compared with the predetermined sequence to determine whether the motor is installed forward or reverse.

[0037] A specific implementation method: The forward state value corresponding to the detection sequence is expressed as follows:

[0038] Among them, hall_status stores the forward status value, and hall1 stores the detection sequence results, such as: forward status value 001 detection sequence result 011; forward status value 010 corresponds to detection sequence 110; forward status value 011 corresponds to detection sequence 010; forward status value 100 corresponds to detection sequence 101; forward status value 101 corresponds to detection sequence 001; forward status value 110 corresponds to detection sequence 100;

[0039] The inversion state value corresponding to the detection sequence is expressed as follows:

[0040] Among them, hall_status stores the reversal status value, and hall1 stores the detection sequence, such as: the reversal status value 001 corresponds to the detection sequence 101; the reversal status value 010 corresponds to the detection sequence 011; the reversal status value 011 corresponds to the detection sequence 001; the reversal status value 100 corresponds to the detection sequence 110; the reversal status value 101 corresponds to the detection sequence 100; the reversal status value 110 corresponds to the detection sequence 010.

[0041] The specific implementation described above is a preferred implementation of a DC brushless motor forward and reverse detection method and system of the present invention, and is not intended to limit the specific implementation scope of the present invention. The scope of the present invention includes but is not limited to this specific implementation. All equivalent changes made in accordance with the shape and structure of the present invention are within the protection scope of the present invention.

Claims

1. A method for detecting forward and reverse rotation of a brushless DC motor: characterized in that: The steps include: S1. Establish circuit connection: connect the power module with the brushless controller, the brushless controller with the brushless motor; connect the forward and reverse detection device with the brushless controller; S2, the three-phase voltage obtained by the voltage division module is used as the positive input voltage of the comparator; S3, a combination signal formed by combining the output values ​​of the comparator, and a plurality of combination signals are stored in a register in a detection sequence according to a time sequence; a commutation table is stored in a detection module in the forward and reverse detection device, and the commutation table has a predetermined sequence formed by a plurality of predetermined combination signals; S4, the detection module obtains the detection sequence in the register and compares it with the predetermined sequence in the commutation table to determine the forward and reverse rotation of the motor; the detection module stores the commutation table, and the commutation table stores the predetermined sequence, which includes the forward state value and the reverse state value corresponding to the detection sequence result; The detection sequence includes variables hall_status and hall1, which store the status values ​​of the comparator outputs twice respectively, wherein hall_status stores the status value of the comparator output for the first time, and hall1 stores the status value of the comparator output for the second time; the acquired detection sequence is compared with the predetermined sequence to determine the forward and reverse rotation of the motor; The eight combination signals output by the comparator and the eight predetermined combination signals in the commutation table are: 111 / 110 / 101 / 100 / 011 / 010 / 001 / 000; the eight detection sequences are stored in the register bit by bit; When the combined signal is 111 or 000, it is a fault state and the forward and reverse detection device alarms.

2. A DC brushless motor forward and reverse detection system, characterized in that: The invention comprises a power module, a brushless controller electrically connected to the power module, and a brushless motor electrically connected to the brushless controller; a forward and reverse detection device is connected in parallel to the three-phase output of the brushless controller, the forward and reverse detection device comprises a voltage dividing module, the voltage divided by the voltage dividing module is used as the positive input voltage of the comparator, the output end of the comparator is electrically connected to the information collection end of the forward and reverse detection device, and the collected combined signal is stored in the corresponding storage position of the register to form a detection sequence; The detection sequence includes variables hall_status and hall1, which store the status values ​​of the comparator output twice respectively, wherein hall_status stores the status value of the comparator output for the first time, and hall1 stores the status value of the comparator output for the second time; The detection system also includes a voltage conversion module, which is connected to the three-phase output terminal of the brushless controller to convert the three-phase electricity into the supply voltage of the forward and reverse detection device; The forward and reverse rotation detection device includes a detection module and a register. The detection module stores a commutation table. The commutation table stores forward state values ​​and reverse state values ​​corresponding to the detection sequence. The register stores a combined signal at the output end of the comparator. The detection module sequentially obtains the motor state results in the register and compares them with the state results in the commutation table to determine the forward and reverse rotation of the motor.

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