Circuit structure for compensating hall deviation of brushless dc motor and method for working of angle controller

Abstract

This invention relates to a circuit structure for compensating Hall effect deviation in a brushless DC motor, comprising a CPU for writing register values; an angle controller for controlling the motor's forward and reverse rotation and compensating for Hall effect deviation; a drive waveform generator for generating a drive waveform based on the angle signal DegOut provided by the angle controller and the amplitude signal rp_AmpIn provided by the CPU; a PWM wave generator for generating a PWM signal to drive the motor's rotation; the motor receiving the PWM signal generated by the PWM wave generator and starting to rotate; and a Hall effect signal detector receiving the Hall sensor signal generated after the motor rotates, processing it, and transmitting it to the angle controller for calibrating the rotor angle. This invention also relates to a method for implementing the angle controller. The circuit structure for compensating Hall effect deviation in a brushless DC motor and the method for operating the angle controller using this invention are quick to learn and easy to operate, requiring minimal technical expertise and reducing development time. This invention does not require complex software programs and consumes minimal CPU resources.

Description

Technical Field

[0001] This invention relates to the field of motor compensation, and more particularly to the field of Hall effect deviation, specifically to a circuit structure for compensating Hall effect deviation in a brushless DC motor and a method for operating an angle controller. Background Technology

[0002] Hall sensors are typically installed in motors to provide feedback on the rotor's position. However, there may be some mechanical deviations during the installation of Hall sensors, which can lead to errors in rotor position angle estimation, fluctuations in average rotor speed, and increased motor noise.

[0003] Currently, most methods for compensating Hall effect deviations use software programs, which require software engineers to write complex programs. This places high demands on the engineers' knowledge of motor theory and mathematics, and also results in long CPU usage times.

[0004] To make a motor rotate, it is necessary to alternately supply power to the coils in a specific sequence. This alternating power supply is called commutation. For brushless DC motors, accurate commutation requires knowledge of the rotor's actual position. Hall effect sensors are a common method for obtaining rotor position information. Generally, three Hall effect sensors are evenly installed in the motor at 120° electrical angles. Theoretically, this arrangement ensures that the Hall signal transitions coincide with the zero-crossing point of the motor's back electromotive force. Figure 1 As shown in (a), the zero-crossing point of the line back EMF is the ideal position point for the brushless DC motor drive control. The brushless DC motor directly uses this Hall moment as the ideal commutation point. However, Hall signal transitions caused by installation deviations can lead to the Hall signal transition leading or lagging behind the zero-crossing point of the motor's line back EMF, such as... Figure 1 (b) and Figure 1 As shown in (c), leading or lagging commutation will cause asymmetry in the waveforms on both sides of the motor terminal voltage, making the motor run unstable. Therefore, Hall deviation needs to be calibrated before commutation can be performed.

[0005] Currently, most methods use software programs to compensate for mechanical deviations in the installation of Hall sensors. Software compensation needs to be achieved based on high-resolution rotor position prediction, speed prediction, and vector control. It requires algorithms such as zero-order Taylor algorithm and Fourier decoupling transform, which require a lot of support from motor theory and mathematical theory and involve a large amount of computation. The implementation process is relatively complex and difficult. Moreover, complex software programs will consume a lot of CPU resources, which is not conducive to the CPU performing other control functions. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a circuit structure and angle controller operation method for compensating for Hall deviation of brushless DC motors that is simple in structure, effective, and widely applicable.

[0007] To achieve the above objectives, the circuit structure for compensating for Hall effect deviation of a brushless DC motor and the method for operating the angle controller of the present invention are as follows:

[0008] The main feature of this circuit structure for compensating for Hall effect deviation in brushless DC motors is that the circuit structure includes:

[0009] The CPU is used to write register values ​​and output angle increment signal rp_DegCntInc, angle controller enable signal rp_DegCntEn, and rotor angle rp_UDeg1~6.

[0010] An angle controller, connected to the CPU, Hall signal detector and PWM wave generator, is used to control the forward and reverse rotation of the motor and to compensate for Hall deviation.

[0011] A drive waveform generator, connected to the CPU and the angle controller, is used to generate a drive waveform based on the angle signal DegOut provided by the angle controller and the amplitude signal rp_AmpIn provided by the CPU.

[0012] A PWM wave generator, connected to the angle controller and the drive waveform generator, is used to generate a PWM signal to drive the motor to rotate based on the drive waveform signal provided by the drive waveform generator.

[0013] The motor is connected to the PWM wave generator and is used to receive the PWM signal generated by the PWM wave generator and start rotating.

[0014] The Hall signal detector, connected to the motor and angle controller, is used to receive the Hall sensor signal generated after the motor rotates. After synchronous filtering, the Hall signals PHU, PHV and PHW are transmitted to the angle controller to select the rotor angle to be calibrated.

[0015] Preferably, the angle controller writes the enable signal rp_DegCntEn transmitted by the CPU, and controls the motor to rotate forward or backward according to the highest bit of the angle increment signal rp_DegCntInc; when the Hall signal changes, the corresponding compensation angle DegCnt_hUVWChg is updated to the angle signal DegOut.

[0016] Preferably, when the highest bit of the angle increment signal rp_DegCntInc is 0, the angle counter performs an addition operation, the value of the angle signal DegOut increases from 0°, the angle increment is the value of the register signal rp_DegCntInc, and the motor rotates in the forward direction; when the highest bit of the angle increment signal rp_DegCntInc is 1, the angle counter performs a subtraction operation, the value of the angle signal DegOut decreases from 360°, the angle decrease is the absolute value of the register signal rp_DegCntInc, and the motor rotates in the reverse direction.

[0017] Preferably, the Hall signals PHU, PHV, and PHW change every 60 degrees.

[0018] Preferably, when the motor rotates in the forward direction, if the value of the angle signal DegOut is greater than or equal to 360°, the angle signal DegOut is cleared to zero and continues to increase from 0°; when the motor rotates in the reverse direction, if the value of the angle signal DegOut is less than or equal to 0°, the angle signal DegOut is set to 9'd360 and continues to decrease from 360°.

[0019] Preferably, the write value of the register signal rp_DegCntInc is in two's complement form.

[0020] The method for implementing the angle controller based on the above circuit structure is characterized by the following steps:

[0021] (1) Configure the angle increment according to the motor speed configuration register rp_DegCntInc, and configure the compensation angle according to the actual position of the Hall sensor installation in the configuration registers rp_UDeg1 to 6; when the configuration register rp_DegCntEn is 1, the motor starts to run.

[0022] (2) Determine whether the angle signal w_DegOut is greater than or equal to 360°. If it is, the motor has rotated one revolution. Clear the angle signal w_DegOut to zero and the motor starts rotating from zero. Otherwise, continue to step (3).

[0023] (3) Determine whether the three-phase Hall signals PHU, PHV and PHW have changed. If so, update the compensation angle DegCnt_hUVWChg corresponding to the Hall signal to the angle signal w_DegOut; otherwise, continue to step (4).

[0024] (4) Determine whether the angle increment trigger signal TRIG is valid. If it is, the angle signal w_DegOut will increment by rp_DegCntInc; otherwise, continue to step (5).

[0025] (5) Keep the angle signal w_DegOut unchanged and continue with step (2).

[0026] The circuit structure and angle controller operation method for compensating Hall effect deviation in brushless DC motors using the present invention are quick to learn and easy to operate, requiring minimal technical expertise and reducing development time. This invention does not require complex software programs, consumes minimal CPU resources, and uses identical code for compensating for leading and lagging commutation, saving chip area. Attached Figure Description

[0027] Figure 1 This is a schematic diagram showing the relative positional relationship between the Hall signal transition edge and the back electromotive force of the motor in existing technology.

[0028] Figure 2 This is a schematic diagram showing the correspondence between the Hall signal and the rotor angle in a circuit structure for compensating Hall deviation in a brushless DC motor according to an embodiment.

[0029] Figure 3 This is a schematic diagram of the hardware control circuit structure for compensating for Hall effect deviation in a brushless DC motor according to the present invention.

[0030] Figure 4 This is a schematic diagram of the angle controller circuit structure for compensating for Hall effect deviation in a brushless DC motor according to the present invention. Detailed Implementation

[0031] To more clearly describe the technical content of the present invention, the following description is provided in conjunction with specific embodiments.

[0032] This invention provides a hardware circuit that can effectively compensate for the installation deviation of the Hall sensor in the motor without complex software programs, saving development costs and reducing CPU usage time.

[0033] Hall position sensors are evenly arranged in 120° electrical angles on the integrated circuit board at the end of the motor. Their magnetic poles mostly use the same number of pole pieces as the motor rotor. Theoretically, this arrangement ensures that the Hall signal transition edge coincides with the zero-crossing point of the motor's linear back electromotive force, allowing for accurate commutation at the Hall signal transition edge. The Hall sensors generate 0 or 1 logic levels based on the polarity of the corresponding magnetic pole piece. When the motor rotates clockwise, the sequence of the three-phase Hall signals {U, V, W} is 5, 4, 6, 2, 3, 1; when rotating counterclockwise, the sequence is 1, 3, 2, 6, 4, 5. The correspondence between the three-phase Hall signals {U, V, W} and the rotor angle during clockwise rotation is as follows: Figure 2As shown in (a), 5 -> 30°, 4 -> 90°, 6 -> 150°, 2 -> 210°, 3 -> 270°, and 1 -> 330°. This Hall effect bias causes the Hall signal to lead or lag. Figure 2 (b) The Hall signal is ahead, meaning the transition edges of the three-phase Hall signals precede the ideal commutation time. For example, 5→28°, 4→87°, 6→149°, 2→208°, 3→268°, 1→327°. Figure 2 (c) Hall signal lag means that the transition edges of the three-phase Hall signals are after the ideal commutation time, such as 5→33°, 4→94°, 6→153°, 2→215°, 3→272°, 1→331°. Leading and lagging commutation will cause fluctuations in the electromagnetic torque of the motor, resulting in unstable motor operation.

[0034] This invention provides a hardware circuit that simply and effectively compensates for installation position deviations of Hall sensors in motors. The hardware circuit structure includes a CPU, an angle controller, a drive waveform generator, a PWM waveform generator, a motor, and a Hall signal detector, as shown in the block diagram below. Figure 3 As shown. The CPU is used to write values ​​to the registers. The register rp_DegCntEn is the enable signal for the angle controller; the angle controller only works when rp_DegCntEn is valid. The register rp_DegCntInc is the angle increment, which can be used to control the forward and reverse rotation of the motor. The registers rp_UDeg1, rp_UDeg2, rp_UDeg3, rp_UDeg4, rp_UDeg5, and rp_UDeg6 are the rotor angles used to update the angle signal DegOut in the angle controller. The register rp_AmpIn is the amplitude of the waveform driving the motor; the larger the amplitude, the faster the motor speed.

[0035] The angle controller is the circuit that controls the forward and reverse rotation of the motor and compensates for Hall effect deviation; it is the core module of this invention.

[0036] The drive waveform generator generates drive waveforms such as square waves and sine waves based on the angle signal DegOut provided by the angle controller and the amplitude signal rp_AmpIn provided by the CPU.

[0037] The PWM wave generator generates a PWM signal that directly drives the motor to rotate based on the drive waveform signal provided by the drive waveform generator.

[0038] The motor starts rotating after receiving the PWM signal.

[0039] The Hall signal detector receives Hall sensor signals A, B, and C after the motor rotates. After processing such as synchronous filtering, it sends Hall signals PHU, PHV, and PHW to the angle controller to select the rotor angle that needs to be calibrated.

[0040] The following only details the angle controller. The angle controller module contains an angle counter. The angle auto-increment trigger signal TRIG from the PWM wave generator and the angle increment signal rp_DegCntInc from the CPU can control the count value of this angle counter to be roughly consistent with the angle of the motor rotor. Moreover, when the Hall signals {PHU, PHV, PHW} change, they will update the current actual rotor angle to the angle counter, thereby making the angle counter more accurate. It can be regarded that the angle counter is synchronized with the angle of the motor rotor. Therefore, the six count values ​​of the angle counter can be directly specified as commutation points, namely: 9'd30, 9'd90, 9'd150, 9'd210, 9'd270, and 9'd330.

[0041] The main circuit structure of the angle controller is as follows Figure 4 As shown, it mainly consists of a selector, comparator, adder, and flip-flop. The angle controller receives register signals rp_DegCntEn, rp_UDeg1~6, and rp_DegCntInc from the CPU, three-phase Hall signals PHU, PHV, and PHW from the Hall signal detector, and the angle increment trigger signal TRIG from the PWM wave generator. Finally, it outputs the angle signal DegOut.

[0042] The value written to register rp_DegCntInc should be in two's complement form.

[0043] When the highest bit of the angle increment signal rp_DegCntInc is 0, the angle counter performs an addition operation, the value of the angle signal DegOut increases from 0°, the angle increment is the value of the register signal rp_DegCntInc, and the motor rotates in the forward direction.

[0044] When the highest bit of the angle increment signal rp_DegCntInc is 1, the angle counter performs a subtraction operation, and the value of the angle signal DegOut decreases from 360°. The angle decrease is the absolute value of the register signal rp_DegCntInc, and the motor rotates in the opposite direction.

[0045] After the motor starts rotating, the Hall signals PHU, PHV, and PHW change every 60 degrees. Whenever the Hall signal changes, the compensation angle DegCnt_hUVWChg corresponding to the Hall value {PHU, PHV, PHW} is updated to the angle signal DegOut, so that the angle signal DegOut is consistent with the rotor angle.

[0046] When the motor rotates forward, if the value of the angle signal DegOut is greater than or equal to 360°, the motor has rotated one revolution. At this time, the angle signal DegOut is cleared to zero and continues to increase from 0°. When the motor rotates in reverse, if the value of the angle signal DegOut is less than or equal to 0°, the motor has rotated one revolution. At this time, the angle signal DegOut is set to 9'd360 and continues to decrease from 360°.

[0047] The method for implementing the angle controller using the above-described circuit structure according to the present invention includes the following steps:

[0048] (1) Combine the motor speed configuration register rp_DegCntInc to set the angle increment; configure the registers rp_UDeg1~rp_UDeg6 according to the actual position of the Hall sensor installation to set the compensation angle; configure register rp_DegCntEn=1, the motor starts to run, and continue to step (2).

[0049] (2) Determine whether the angle signal w_DegOut is greater than or equal to 360°. If yes, it means that the motor has rotated one revolution. Clear the angle signal w_DegOut to 0 and the motor starts to rotate from 0°. If no, continue to step (3).

[0050] (3) Determine whether the three-phase Hall signals PHU, PHV, and PHW have changed. If yes, update the compensation angle DegCnt_hUVWChg corresponding to the Hall signal to the angle signal w_DegOut. If no, continue to step (4).

[0051] (4) Determine whether the angle increment trigger signal TRIG is valid (active high). If yes, the angle signal w_DegOut = w_DegOut + rp_DegCntInc; if no, continue to step (5).

[0052] (5) The angle signal w_DegOut remains unchanged, and continue with step (2).

[0053] This invention is illustrated using the circuit structure described above as an example only. The scope of this invention includes, but is not limited to, the circuit structure described above, and is still applicable to other hardware circuit structures that can compensate for Hall deviation through Hall signals.

[0054] With this invention, simply writing the corresponding actual rotor angle into registers rp_UDeg1 to rp_UDeg6 can effectively compensate for the leading and lagging commutation caused by Hall bias, making the operation simple and flexible.

[0055] Embodiment 1 of the present invention is as follows Figure 2As shown in (a), the rotor angle corresponding to the Hall signal transition edge is consistent with the ideal commutation angle. In step 1, the values ​​written to registers rp_UDeg1 to rp_UDeg6 are: rp_UDeg5 -> 9'd30, rp_UDeg4 -> 9'd90, rp_UDeg6 -> 9'd150, rp_UDeg2 -> 9'd210, rp_UDeg3 -> 9'd270, rp_UDeg1 -> 9'd330. In step 3, when the Hall signal changes, 9'd30, 9'd90, 9'd150, 9'd210, 9'd270, and 9'd330 are updated in the angle signal DegOut, and the motor will immediately commutate.

[0056] Embodiment 2 of the present invention is as follows Figure 2 As shown in (b), the rotor angle corresponding to the Hall signal transition edge leads the ideal commutation angle. In step 1, the values ​​written to registers rp_UDeg1 to rp_UDeg6 are: rp_UDeg5 -> 9'd28, rp_UDeg4 -> 9'd87, rp_UDeg6 -> 9'd149, rp_UDeg2 -> 9'd208, rp_UDeg3 -> 9'd268, rp_UDeg1 -> 9'd327. In step 3, when the Hall signal changes, 9'd28, 9'd87, 9'd149, 9'd208, 9'd268, and 9'd327 are updated in the angle signal DegOut, calibrating the angle signal DegOut. The angle signal DegOut continues to increment until the specified commutation angle is reached for commutation.

[0057] Embodiment 3 of the present invention is as follows Figure 2 As shown in (c), the rotor angle corresponding to the Hall signal transition lags behind the ideal commutation angle. In step 1, the values ​​written to registers rp_UDeg1-6 are: rp_UDeg5->9'd33, rp_UDeg4->9'd94, rp_UDeg6->9'd153, rp_UDeg2->9'd215, rp_UDeg3->9'd272, rp_UDeg1->9'd331. In step 3, when the Hall signal changes, the motor has already commutated at the specified angle. Updating 9'd33, 9'd94, 9'd153, 9'd215, 9'd272, and 9'd331 to the angle signal DegOut calibrates the angle signal DegOut to make the timing of the next commutation more accurate.

[0058] The circuit structure and angle controller operation method for compensating Hall effect deviation in brushless DC motors using the present invention are quick to learn and easy to operate, requiring minimal technical expertise and reducing development time. This invention does not require complex software programs, consumes minimal CPU resources, and uses identical code for compensating for leading and lagging commutation, saving chip area.

[0059] In this specification, the invention has been described with reference to specific embodiments thereof. However, it will be apparent that various modifications and variations can be made without departing from the spirit and scope of the invention. Therefore, the specification and drawings should be considered illustrative rather than restrictive.

Claims

1. A circuit structure for compensating Hall effect deviation in a brushless DC motor, characterized in that, The circuit structure comprises: a CPU for writing register values, outputting an angle increment signal rp_DegCntInc, an enable signal rp_DegCntEn of an angle controller, and rotor angles rp_UDeg1-6; an angle controller connected with the CPU, a Hall signal detector and a PWM wave generator, for controlling the forward and reverse rotation of a motor and compensating for Hall deviation; a drive wave generator connected with the CPU and the angle controller, for generating a drive wave according to an angle signal DegOut provided by the angle controller and an amplitude signal rp_AmpIn provided by the CPU; a PWM wave generator connected with the angle controller and the drive wave generator, for generating a PWM signal for driving the motor to rotate and an angle self-increment trigger signal TRIG according to a drive wave signal provided by the drive wave generator; a motor connected with the PWM wave generator, for receiving the PWM signal generated by the PWM wave generator and starting to rotate; a Hall signal detector connected with the motor and the angle controller, for receiving Hall sensor signals generated after the motor rotates, performing synchronous filtering processing, and transmitting Hall signals PHU, PHV and PHW to the angle controller to select rotor angles to be calibrated; the angle controller receives the angle increment signal rp_DegCntInc, the enable signal rp_DegCntEn and the rotor angles rp_UDeg1-6 provided by the CPU, the three-phase Hall signals PHU, PHV and PHW provided by the Hall signal detector, and the angle self-increment trigger signal TRIG provided by the PWM wave generator, and outputs an angle signal DegOut; and the angle controller is further provided with an angle counter, the counting value of the angle counter is synchronized with the angle of the rotor of the motor, so that the motor performs commutation processing according to the specified counting value.

2. The circuit structure for compensating for Hall deviation of a brushless DC motor according to claim 1, wherein, The angle controller writes the enable signal rp_DegCntEn transmitted by the CPU, controls the motor to rotate forward or reversely according to the highest bit of the angle increment signal rp_DegCntInc, and updates the corresponding compensation angle DegCnt_hUVWChg to the angle signal DegOut when the Hall signal changes.

3. The circuit structure for compensating for Hall deviation of a brushless DC motor according to claim 1, wherein, When the highest bit of the angle increment signal rp_DegCntInc is 0, the angle counter performs addition operation, the value of the angle signal DegOut increases from 0°, the angle increment is the value of the register signal rp_DegCntInc, and the motor rotates forward; when the highest bit of the angle increment signal rp_DegCntInc is 1, the angle counter performs subtraction operation, the value of the angle signal DegOut decreases from 360°, the angle decrement is the absolute value of the register signal rp_DegCntInc, and the motor rotates reversely.

4. The circuit structure for compensating for Hall deviation of a brushless DC motor according to claim 1, wherein, The Hall signals PHU, PHV and PHW change every 60 degrees.

5. The circuit structure for compensating for Hall deviation of a brushless DC motor according to claim 1, wherein, In the case that the motor rotates forward, if the value of the angle signal DegOut is greater than or equal to 360°, the angle signal DegOut is cleared and continues to increase from 0°; in the case that the motor rotates reversely, if the value of the angle signal DegOut is less than or equal to 0°, the angle signal DegOut is set to 9'd360 and continues to decrease from 360°.

6. The circuit structure for compensating for Hall deviation of a brushless DC motor according to claim 3, wherein, The writing value of the register signal rp_DegCntInc is in the form of a complement.

7. A method for operating an angle controller based on the circuit structure of claim 1, characterized by The method comprises the following steps: (1) configuring the register rp_DegCntInc according to the motor rotating speed to set the angle increment, and configuring the registers rp_UDeg1-6 according to the actual position of the Hall sensor to set the compensation angle; in the case that the configuration register rp_DegCntEn is 1, the motor starts to operate; (2) judging whether the angle signal w_DegOut is greater than or equal to 360°, if yes, the motor has rotated one round, the angle signal w_DegOut is cleared and the motor starts to rotate from zero; otherwise, continue to step (3); (3) judging whether the three-phase Hall signals PHU, PHV and PHW change, if yes, updating the compensation angle DegCnt_hUVWChg corresponding to the Hall signal to the angle signal w_DegOut; otherwise, continue to step (4); (4) judging whether the angle self-increment trigger signal TRIG is valid, if yes, the angle signal w_DegOut is subjected to the self-increment operation and the increment is rp_DegCntInc; otherwise, continue to step (5); (5) keeping the angle signal w_DegOut unchanged and continuing to step (2).

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