Monopolar and bipolar hybrid motor driving method and driving circuit

Abstract

The embodiment of the invention provides a unipolar and bipolar hybrid motor driving method and a driving circuit. The method comprises the following steps: detecting logic states of a first control signal and a second control signal; when the logic states of the first control signal and the second control signal are different, entering a unipolar control mode; in the unipolar control mode, the rotation direction of the motor is determined by the logic state combination of a first control signal and a second control signal, and the rotation speed of the motor is controlled through the duty ratio of a pulse width modulation signal. When the logic states of the first control signal and the second control signal are the same, entering a bipolar control mode or a braking mode; wherein the bipolar control mode or the brake mode controls the rotating direction and the rotating speed of the motor through the duty ratio of a pulse width modulation signal. By intelligently sensing the state of a motor control input signal, a unipolar or bipolar driving mode is adaptively selected, so that a motor system can operate efficiently and stably within a full working condition range.

Description

Technical Field

[0001] The embodiments in this specification relate to the field of circuit technology, and in particular to a hybrid single- and bipolar motor drive method. Background Technology

[0002] Motor drivers are widely used in various fields, such as medical imaging, precision manufacturing, aerospace servos, and acoustic equipment. When designing driver circuits, designers need to consider factors such as application scenarios, market demands, control methods, and power consumption.

[0003] Currently, the advantages of unipolar control are small voltage amplitude during switching within a single cycle, low switching and conduction losses, low voltage change rate, and simple control logic. However, at extremely low duty cycles, the current is discontinuous, which can easily cause motor jitter and unstable torque. Bipolar control, on the other hand, maintains a continuous current throughout a control cycle, producing very stable and precise torque even at extremely low speeds. It offers quieter and smoother operation, faster dynamic response, and stronger braking capability. However, the switching transistors experience greater voltage and current stress, resulting in significant switching and conduction losses and increased susceptibility to electromagnetic interference. Furthermore, the motor's operating state changes under different application scenarios; using unipolar control can lead to uneven motor efficiency.

[0004] To avoid the problem of uneven efficiency of motors due to a single control method in different application scenarios and working conditions, it is necessary to propose a hybrid drive method that combines single and dual polarity, which is essentially an intelligent "working condition adaptive" strategy. Summary of the Invention

[0005] In view of this, embodiments of this specification provide a method and circuit for driving a hybrid single- and bipolar motor to address the technical deficiencies existing in the prior art.

[0006] According to a first aspect of the embodiments of this specification, a hybrid single- and bipolar motor driving method is provided, comprising: Detect the logic state of the first control signal and the second control signal; When the logic states of the first control signal and the second control signal are different, the system enters the unipolar control mode. In the unipolar control mode, the direction of the motor is determined by the combination of the logic states of the first control signal and the second control signal, and the speed of the motor is controlled by the duty cycle of the pulse width modulation signal. When the logic states of the first control signal and the second control signal are the same, the system enters either bipolar control mode or braking mode. In bipolar control mode or braking mode, the direction and speed of the motor are controlled by the duty cycle of the pulse width modulation signal.

[0007] In one possible implementation, the bipolar control mode includes: Within one cycle of the pulse width modulation signal, the voltage across the motor is controlled to alternate between the positive power supply voltage and the negative power supply voltage. By controlling the duty cycle of the pulse width modulation signal to control the ratio of the positive voltage application time to the negative voltage application time within one cycle, the direction and magnitude of the average voltage of the motor can be controlled, thereby realizing the forward rotation, reverse rotation or stop of the motor.

[0008] In one possible implementation, the motor rotates forward when the duty cycle of the pulse width modulation signal is greater than 50%. When the duty cycle of the pulse width modulation signal is less than 50%, the motor reverses. When the duty cycle of the pulse width modulation signal is 50%, the average voltage of the motor is zero, and it is in a stopped state.

[0009] In one possible implementation, the braking mode is as follows: When both the first control signal and the second control signal are at a low level, all the high-side switches of the motor drive circuit are turned off, and all the low-side switches are turned on, causing short-circuit braking at both ends of the motor.

[0010] According to a second aspect of the embodiments of this specification, a single- and bipolar hybrid drive circuit for implementing a control method is provided, characterized in that it includes: The logic control unit is used to receive a first control signal, a second control signal, and a pulse width modulation signal, and output a mode selection signal and a corresponding gate control logic signal. The gating unit, connected to the logic control unit, is used to select the gate drive control signal in either unipolar or bipolar control mode based on the mode selection signal. The driving unit, connected to the gating unit, is used to generate and output the gate driving voltage for controlling the turn-on or turn-off of each power switch in the H-bridge circuit based on the gate driving control signal.

[0011] In one possible implementation, the logic control unit includes: The first logic module is used to generate a first set of control signals for bipolar control mode based on the pulse width modulation signal; The second logic module is used to generate a second set of control signals for unipolar control mode based on the first control signal and the second control signal, and to generate a mode selection signal that characterizes whether the logic states of the first control signal and the second control signal are the same.

[0012] In one possible implementation, the first logical module includes: The first control sub-circuit is used to generate complementary signals for controlling the high-side and low-side switches of the first arm of the H-bridge based on the pulse width modulation signal. The second control sub-circuit is used to generate complementary signals for controlling the high-side and low-side switches of the second arm of the H-bridge based on the pulse width modulation signal.

[0013] In one possible implementation, the second logical module includes: A signal conversion circuit is used to convert the external level of the first control signal and the second control signal into the internal logic level; The logic operation circuit is used to perform an XOR operation on the logic levels of the converted first and second control signals, and output a mode selection signal.

[0014] In one possible implementation, the gating unit includes multiple gating circuits, each gating circuit corresponding to a switch in the H-bridge circuit; Each gating circuit is configured as follows: When the mode selection signal indicates the unipolar control mode, the corresponding control signal from the second logic module is output to the drive unit; When the mode selection signal indicates the bipolar control mode, the corresponding control signal from the first logic module is output to the drive unit.

[0015] In one possible implementation, the driving circuit is integrated into a single chip, and the first control signal, the second control signal, and the pulse width modulation signal are accessed through the chip's input pins.

[0016] This specification provides a hybrid unipolar and bipolar motor driving method and circuit. The method includes: detecting the logic states of a first control signal and a second control signal; when the logic states of the first control signal and the second control signal are different, entering a unipolar control mode; wherein, in the unipolar control mode, the motor direction is determined by the combination of the logic states of the first and second control signals, and the motor speed is controlled by the duty cycle of a pulse width modulation signal; when the logic states of the first control signal and the second control signal are the same, entering a bipolar control mode or a braking mode; wherein, in the bipolar control mode or braking mode, the motor direction and speed are controlled by the duty cycle of the pulse width modulation signal. By intelligently sensing the state of the motor control input signal, the unipolar or bipolar drive mode is adaptively selected, enabling the motor system to achieve both high efficiency and stable operation across the entire operating range. Attached Figure Description

[0017] Figure 1 This is a flowchart of a hybrid single- and bipolar motor driving method provided in one embodiment of this specification; Figure 2A schematic diagram of the current path when a positive voltage is applied in a bipolar control mode, as provided in one embodiment of this specification; Figure 3 A schematic diagram of the current path when a reverse voltage is applied in a bipolar control mode, as provided in one embodiment of this specification; Figure 4 This is a schematic block diagram of a unipolar / bipolar hybrid drive circuit provided in one embodiment of this specification.

[0018] Figure 5 The following is a driving logic circuit diagram of the PWM_logic module controlling the A-phase bridge arm provided in one embodiment of this specification; Figure 6 The following is a driving logic circuit diagram of the PWM_logic module controlling the B-phase bridge arm provided in one embodiment of this specification; Figure 7 This specification provides a circuit diagram of the INA pin logic conversion circuit of the INA / INB_logic module in one embodiment. Figure 8 The logic conversion circuit diagram of the INB pin of the INA / INB_logic module provided in one embodiment of this specification; Figure 9 This specification provides an XOR gate logic circuit diagram for generating a mode selection signal in one embodiment. Figure 10 This is a circuit diagram of the gating unit for the high-side drive of phase A provided in one embodiment of this specification; Figure 11 A waveform diagram of the motor rotating forward when switching from unipolar mode to bipolar mode in a simulation experiment provided for one embodiment of this specification; Figure 12 The waveform diagram shows the motor reversing when switching from unipolar mode to bipolar mode in a simulation experiment provided for one embodiment of this specification. Detailed Implementation

[0019] Many specific details are set forth in the following description to provide a full understanding of this specification. However, this specification can be implemented in many other ways than those described herein, and those skilled in the art can make similar extensions without departing from the spirit of this specification. Therefore, this specification is not limited to the specific implementations disclosed below.

[0020] The terminology used in one or more embodiments of this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the one or more embodiments of this specification. The singular forms “a” and “the” as used in one or more embodiments of this specification and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in one or more embodiments of this specification refers to and includes any or all possible combinations of one or more associated listed items.

[0021] It should be understood that although the terms first, second, etc., may be used to describe various information in one or more embodiments of this specification, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, first may also be referred to as second without departing from the scope of one or more embodiments of this specification, and similarly, second may also be referred to as first. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to a determination."

[0022] This specification provides a method and circuit for driving a hybrid monopolar and bipolar motor, which will be described in detail in the following embodiments.

[0023] See Figure 1 , Figure 1 A flowchart of a hybrid monopolar and bipolar motor driving method according to an embodiment of this specification is shown, which specifically includes the following steps.

[0024] Step 101: Detect the logic state of the first control signal (INA) and the second control signal (INB); In practical applications, this application designs a control method that combines two polarity modes, that is, different polarity controls are selected according to different combinations of the states of unipolar and bipolar input pins.

[0025] Step 102: When the logic states of the first control signal (INA) and the second control signal (INB) are different, the unipolar control mode is entered; wherein, the direction of the motor is determined by the combination of the logic states of the first control signal (INA) and the second control signal (INB), and the speed of the motor is controlled by the duty cycle of the pulse width modulation signal (PWM). In one possible implementation, the bipolar control mode includes: controlling the voltage across the motor to alternate between a positive power supply voltage (+VCC) and a negative power supply voltage (-VCC) within one cycle of the pulse width modulation (PWM) signal; controlling the ratio of the positive voltage duration to the negative voltage duration within one cycle by controlling the duty cycle of the pulse width modulation (PWM) signal, thereby controlling the direction and magnitude of the average voltage of the motor, and realizing the forward rotation, reverse rotation or stop of the motor.

[0026] In practical applications, the control logic principle combining unipolar and bipolar drive methods and the bipolar control logic are shown in Table 1 and Table 2: Table 1 is the truth table of the combined unipolar and bipolar control principle.

[0027] Where "1" represents on and "0" represents off.

[0028] Step 103: When the logic states of the first control signal (INA) and the second control signal (INB) are the same, enter the bipolar control mode or braking mode; wherein, the bipolar control mode or braking mode controls the direction and speed of the motor through the duty cycle of the pulse width modulation signal (PWM).

[0029] In practical applications, the bipolar control logic is shown in Table 2: In the logic control circuit, when the input INA and INB pins are in the same state, the circuit enters bipolar control mode or braking mode. In this mode, the duty cycle of the PWM signal determines the direction and speed of the motor. When the input INA and INB pins are in different states, the circuit enters unipolar control mode. In this mode, the direction of the motor is determined by the states of the INA and INB pins, while the duty cycle of the PWM signal only controls the speed of the motor.

[0030] Table 2 is the truth table for the bipolar control principle.

[0031] Where "1" represents on and "0" represents off.

[0032] In one possible implementation, the motor rotates forward when the duty cycle of the pulse width modulation (PWM) signal is greater than 50%; the motor rotates in reverse when the duty cycle of the pulse width modulation (PWM) signal is less than 50%; and the motor is in a stopped state when the duty cycle of the pulse width modulation (PWM) signal is equal to 50%.

[0033] Furthermore, the braking mode is as follows: when both the first control signal (INA) and the second control signal (INB) are at a low level, all high-side switches of the motor drive circuit are turned off, and all low-side switches are turned on, causing short-circuit braking at both ends of the motor.

[0034] In practical applications, the core characteristic of bipolar control in H-bridge motor drive circuits is that the polarity of the voltage applied across the motor alternates between positive and negative during each PWM signal cycle. That is, the voltage across the motor switches rapidly between +VCC and -VCC, and the direction and magnitude of the average voltage are determined by the duty cycle of the input PWM signal. In bipolar control, switching transistors are typically controlled in pairs diagonally, with two main states, as described below.

[0035] State 1: When a positive voltage is applied (i.e., when the PWM signal is high), HSA and LSB are turned on, while HSB and LSA are turned off. The current path is VCC→HSA→OUTA→motor→OUTB→LSB→GND, and the current flow direction is as follows. Figure 2 As shown, the voltage at point OUTA is VCC and the voltage at point OUTB is GND. Therefore, the voltage across the motor is +VCC and the current flows through the motor from left to right.

[0036] State 2: When a reverse voltage is applied (i.e., when the PWM signal is low), HSB and LSA are turned on, while HSA and LSB are turned off. The current path is VCC→HSB→OUTB→Motor→OUTA→LSA→GND, and the current flow is as follows: Figure 3 As shown, the voltage at point OUTB is VCC and the voltage at point OUTA is GND. Therefore, the voltage across the motor is -VCC, and the current flows through the motor from right to left.

[0037] In an actual PWM cycle, states one and two alternate rapidly. The essence of the PWM signal controlling the forward and reverse rotation of the motor is to compare the duration of positive polarity conduction with the duration of negative polarity conduction within one cycle. When the duration of positive polarity conduction is greater than the duration of negative polarity conduction, the average voltage across the motor is positive, and the average current flows from OUTA to OUTB, causing the motor to rotate forward. When the duration of negative polarity conduction is greater than the duration of positive polarity conduction, the average voltage across the motor is negative, and the average current flows from OUTB to OUTA, causing the motor to rotate in reverse. When the duration of positive polarity conduction is equal to the duration of negative polarity conduction, the average voltage across the motor is zero, and the motor stops.

[0038] Therefore, when the duty cycle of the PWM signal is greater than 50%, the time for applying +VCC is longer than the time for applying -VCC in one cycle, the average voltage is positive, and the motor rotates in the forward direction; when the duty cycle is 50%, the time for applying +VCC and the time for applying -VCC are equal in one cycle, the average voltage is zero, the motor stops rotating, but there will be high-frequency jitter; when the duty cycle is less than 50%, the time for applying +VCC is shorter than the time for applying -VCC in one cycle, the average voltage is negative, and the motor rotates in the reverse direction.

[0039] This application also provides a single- and bipolar hybrid drive circuit for implementing the control method, such as Figure 4 As shown, it includes: a logic control unit, used to receive a first control signal (INA), a second control signal (INB), and a pulse width modulation signal (PWM), and output a mode selection signal and a corresponding gate control logic signal; a gating unit, connected to the logic control unit, used to select the output gate drive control signal in unipolar control mode or bipolar control mode according to the mode selection signal; and a drive unit, connected to the gating unit, used to generate and output the gate drive voltage for controlling the turn-on or turn-off of each power switch in the H-bridge circuit according to the gate drive control signal.

[0040] In practical applications, this application adds a PWM pin to the original control method and designs a bipolar control logic circuit to control the motor's rotation direction and speed.

[0041] Specifically, INA is the A-phase control drive logic input pin, INB is the B-phase control drive logic input pin, and PWM is a logic input pin. PWM control is enabled, and the inputs are signals from the PWM, INA, and INB pins. After processing by the PWM_logic module and the INA / INB_logic module, seven intermediate logic signals are output: H_colseHA, H_colseLA, H_colseHB, H_colseLB, ina1, inb1, and inab10_h. These logic signals enter the gating unit and output four gate drive control signals: gate_on_ha, gate_on_hb, gate_on_la, and gate_on_lb. After entering the drive unit, the gate drive control signals finally output four gate drive voltages from GHA, GLA, GHB, and GLB to control... Figure 2 and Figure 3 The high-side and low-side MOSFETs are turned on and off. GHA is the gate drive output of phase A high-side, GLA is the gate drive output of phase A low-side, GHB is the gate drive output of phase B high-side, and GLB is the gate drive output of phase B low-side.

[0042] In bipolar control mode, the PWM signal controls the gate drive logic signals of the four switching transistors. When the PWM signal is high, HSA and LSB are enabled, while HSB and LSA are disabled; when the PWM signal is low, HSB and LSA are enabled, while HSA and LSB are disabled. Here, RS flip-flops are used to implement PWM control of the four gate drive logics.

[0043] When the input INA and INB pins are in different states, the system enters unipolar control mode. An XOR gate and a strobe are used to select between unipolar and bipolar control states. The duty cycle of the PWM signal only controls the motor speed. When INA is high and INB is low, the XOR gate outputs a high level, selecting unipolar control. In this mode, HSA and LSB are enabled, while HSB and LSA are disabled, and the motor rotates forward. When INA is low and INB is high, the XOR gate still outputs a high level, selecting unipolar control. In this mode, HSB and LSA are enabled, while HSB and LSB are disabled, and the motor rotates in reverse. When both INA and INB are high, the XOR gate outputs a low level, entering bipolar control mode. In this mode, the duty cycle of the PWM signal controls the motor's direction and speed. When both INA and INB are low, the XOR gate outputs a low level, entering braking mode. In this mode, LSA and LSB are enabled, while HSA and HSB are disabled, and the motor stops.

[0044] In one possible implementation, the logic control unit includes: a first logic module for generating a first set of control signals for a bipolar control mode based on a pulse width modulation (PWM) signal; and a second logic module for generating a second set of control signals for a unipolar control mode based on a first control signal (INA) and a second control signal (INB), and generating a mode selection signal characterizing whether the logic states of the first control signal (INA) and the second control signal (INB) are the same.

[0045] In practical applications, the logic control unit can be a logic control circuit, specifically including: a PWM_logic module, an INA_logic module, an INB_logic module, and a gating unit; wherein, the first logic module can be a PWM_logic module, and the second logic module can include an INA_logic module and an INB_logic module.

[0046] In one possible implementation, the first logic module includes: a first control sub-circuit for generating complementary signals for controlling the high-side and low-side switches of the first arm of the H-bridge based on a pulse width modulation (PWM) signal; and a second control sub-circuit for generating complementary signals for controlling the high-side and low-side switches of the second arm of the H-bridge based on a pulse width modulation (PWM) signal.

[0047] In practical applications, the PWM_logic module receives the PWM signal and generates H_colseHA and H_colseLA signals, which are inverses of each other; it also generates H_colseHB and H_colseLB signals, which are inverses of each other. These four signals are further processed by the gating unit, ultimately outputting four gate drive control signals, namely the four gate drive control signals mentioned above: gate_on_ha, gate_on_hb, gate_on_la, and gate_on_lb. Specifically, the PWM_logic module generates the circuit as follows: Figure 5 and Figure 6 As shown, this module is the logic control circuit for the PWM signal. When the motor enters the bipolar control mode, the PWM signal simultaneously controls the four gate drives. Figure 5 This is the drive logic circuit for controlling the high and low sides of phase A using PWM signals. Figure 6 This is a drive logic circuit for controlling the high and low sides of phase B using PWM signals.

[0048] like Figure 5 As shown, during normal operation, this module receives the input PWM signal. After power-on, the enable EN generates a small high-level pulse, resetting the output terminal H1 of nor_2 to zero. When the PWM signal is high, the output terminal G1 of nor_1 is at zero potential. Simultaneously, the PWM signal is inverted by inverter not1 and input to nor_2, resulting in a high potential at the output terminal H1 of nor_2. At this time, the output signals H_closeHA and H_closeLA are low and high, respectively. These two signals are input to the driver circuit logic control module, enabling HSA and disabling LSA. When the PWM signal is low, it is inverted by inverter not1 and input to nor_2, resulting in a low potential at the output terminal H1 of nor_2. Simultaneously, the output terminal G1 is high, resulting in a high potential at the output signal H_closeHA and H_closeLA, respectively. HSA is disabled and LSA is enabled.

[0049] like Figure 6As shown, during normal operation, this module receives a PWM signal. After power-on, the enable EN generates a small high-level pulse, resetting the output H2 of nor_4 to zero. When the PWM signal is high, the potential of the output H2 of nor_4 is zero. Simultaneously, the PWM signal is inverted by inverter not4 and input to nor_3, resulting in a high potential at the output G2 of nor_3. At this time, the output H_closeHB signal is high and the H_closeLB signal is low. These two signals are input to the driver circuit logic control module, turning off HSB and turning on LSB. When the PWM signal is low, it is inverted by inverter not4 and input to nor_3, resulting in a low output G2 of nor_3. Simultaneously, the H2 point is high, resulting in a low output H_closeHB signal and a high output H_closeLB signal. These two signals are input to the driver circuit logic control module, turning on HSB and turning off LSB.

[0050] In one possible implementation, the second logic module includes: a signal conversion circuit for converting the external levels of the first control signal (INA) and the second control signal (INB) into internal logic levels; and a logic operation circuit for performing an XOR operation on the converted logic levels of the first control signal (INA) and the second control signal (INB) to output a mode selection signal.

[0051] In practical applications, the INAB_logic module has the following inputs: INA and INB pins, with 100KΩ pull-down resistors to ground. The outputs are ina1 and inb1 signals, which control the gate drive signals of HSA, LSA, HSB, and LSB, respectively. The inab10_h signal is also output; when the INA and INB pins are in the same state, inab10_h is low; when the INA and INB pins are in different states, inab10_h is high.

[0052] Specifically, the INA / / INB_logic module generates the circuit as follows: Figure 7 and Figure 8 As shown. This module is a logic conversion and logic operation circuit for the INA and INB pins, and its output is the logic high and low levels corresponding to the states of the INA and INB pins, and the logic level obtained by XORing these two logic levels.

[0053] See Figure 7The first ends of resistors R0 and R1 are both connected to the INA pin. The second end of resistor R0 is connected to GND. The second end of resistor R1 is connected to the drain of MOSFET M1 via resistor R3, and also to the gates of M0 and M2. The source of M1 is connected to GND. The first end of resistor R2 is connected to the power supply voltage VDD, and the second end is connected to the gate of M1 and the drain of M0. The source of M0 is connected to the drain of M2, and the source of M2 is connected to GND. The source of M3 is connected to the power supply VDD, and the gate and drain of M3 are connected to the gate and drain of M4, respectively. The gates of M3 and M4 are both connected to the drain of M0. When the INA pin is connected to a high potential, the potential at point O is pulled up to VDD through resistor R1, M2 conducts, pulling the potential at point P1 low, and M1 is turned off. An inverter composed of M3 and M4 is then connected, and the output of INA1 is logic high, achieving the conversion of high voltage to logic high level. When the INA pin is connected to a low potential, the voltage at point N is GND, transistor M2 is cut off, and the potential at point P1 is pulled up to VDD through resistor R2. This is then connected to an inverter formed by M3 and M4, causing the INA1 output to be logic low, thus converting the high voltage to a logic high level. Furthermore, the INA pin uses a 100K pull-down resistor R0. When the INA pin is floating, it is pulled down to GND by default.

[0054] In unipolar control mode, when the output ina1 signal is high, it is input to the driver circuit logic control module to control HSA to turn on and LSA to turn off; when the output ina1 signal is low, it is input to the driver circuit logic control module to control HSA to turn off and LSA to turn on.

[0055] See Figure 8The first ends of resistors R4 and R5 are both connected to the INB pin. The second end of resistor R4 is connected to GND. The second end of resistor R5 is connected to the drain of MOSFET M7 via resistor R7, and to the gates of M8 and M9. The source of M7 is connected to GND. The first end of resistor R6 is connected to the power supply voltage VDD, and the second end is connected to the gate of M7 and the drain of M9. The source of M9 is connected to the drain of M8, and the source of M8 is connected to GND. The source of M5 is connected to the power supply VDD, and the gate and drain of M5 are connected to the gate and drain of M6, respectively. The gates of M5 and M6 are both connected to the drain of M9. When the INB pin is connected to a high potential, the potential at point O2 is pulled up to VDD through resistor R5, MOSFET M8 conducts, pulling the potential at point P2 low. At the same time, M7 is cut off. An inverter composed of M5 and M6 is then connected, and the output of inb1 is a logic high level, realizing the conversion of high voltage to logic high level. When the INB pin is connected to a low potential, the voltage at point O2 is GND, transistor M8 is cut off, and the potential at point P2 is pulled up to VDD through resistor R6. This is then connected to an inverter formed by M5 and M6, resulting in a logic low output for inb1, thus converting the high voltage to a logic high level. Furthermore, the INB pin uses a 100K pull-down resistor R4. When the INB pin is floating, it is pulled down to GND by default. In unipolar control mode, when the output inb1 signal is high, it is input to the driver circuit logic control module, controlling HSB to turn on and LSB to turn off; when the output inb1 signal is low, it is input to the driver circuit logic control module, controlling HSB to turn off and LSB to turn on.

[0056] See Figure 9 As shown, Figure 9 This is an XOR gate logic circuit. When both ina1 and inb1 signals are high or both are low, the output inab10_h signal is low. When one of the ina1 and inb1 signals is high and the other is low, the output inab10_h signal is high.

[0057] In one possible implementation, the gating unit includes multiple gating circuits, each corresponding to a switch in the H-bridge circuit; each gating circuit is configured to: when the mode selection signal indicates a unipolar control mode, output the corresponding control signal from the second logic module to the driving unit; when the mode selection signal indicates a bipolar control mode, output the corresponding control signal from the first logic module to the driving unit.

[0058] In practical applications, the drive unit is an existing module primarily used to convert the four gate drive control signals output from the gating unit into gate drive voltages to control the on / off state of the high-side and low-side switching transistors. Specifically, the gating unit receives the status of the INA and INB pins, outputs signals, and generates PWM signals to turn the drive transistors on or off. When the INA and INB pins are in the same state, the signal output from the PWM_logic module controls the gate drive; when the INA and INB pins are in different states, the signal output from the INAB_logic module controls the gate drive. Simultaneously, the duty cycle of the PWM signal controls the low-side gate drive to achieve speed regulation.

[0059] Specifically, the signal generation circuit of the gating unit is as follows: Figure 10 As shown, the sources of MOSFETs MP1 and MP3 are connected to the power supply VDD. The gate of MP1 receives the H_colseHA_ signal, and the gate of MP3 receives the ina1 signal. The drain of MP1 is connected to the source of MP2. The gate of MP2 receives the inab10_h signal. The gate and drain of MN1 are connected to the gate and drain of MP2, respectively. The source of MN1 is connected to the drain of MN2. The gate of MN2 receives the ina1 signal, and the source of MN2 is connected to GND. The drain of MP3 and the source of MP4... The MP4 gate input is the inverted signal of the inab10_h signal. The gate and drain of MN3 are connected to the gate and drain of MP4 respectively. The gate input of MN4 is the H_colseHA signal. The drain of MN2 is connected to GND. The drain voltage of MP4 is inverted by a NOT gate and outputs the gate_on_ha signal. This module is the selection control logic circuit. The inab10_h signal is used for selection. After distinguishing between unipolar control and bipolar control, the output selects the input control logic for different control modes. When the inab10_h signal is high, MN1 and MP4 are turned on, and MN3 and MP2 are turned off, entering the unipolar control mode. At this time, the gate control output signal gate_on_ha is controlled by the ina1 signal. When ina1 is high, the potential of point Q is pulled low, the output gate_on_h signal is high, and HSA is turned on; when ina1 is low, the potential of point Q is pulled high, the output gate_on_h signal is low, and HSA is turned off.

[0060] When the inab10_h signal is low, transistors MN3 and MP2 are turned on, while transistors MN1 and MP4 are turned off, entering bipolar control mode. At this time, the gate control output signal gate_on_ha is controlled by the H_colseHA signal generated by the PWM signal. The H_colseHA signal and the H_colseHA signal (generated by the PWM signal) are shown in the diagram. Figure 5The outputs (not 2) are inverted. When H_colseHA is high, H_colseHA_ is low, the potential at point Q is pulled high, the output gate_on_h signal is low, and HSA is off. When H_colseHA is low, H_colseHA_ is high, the potential at point Q is pulled low, the output gate_on_ha signal is high, and HSA is on. This module operates on the same principle as the A-phase low-side drive and the B-phase high / low-side drive gating unit.

[0061] The proposed solution constructs a logic circuit using a bipolar control method. A single PWM pin enables the on / off state of four transistors. Simultaneously, the duty cycle of the PWM signal determines the motor's forward / reverse rotation and speed control. When the PWM duty cycle is greater than 50%, the positive polarity conduction time is longer than the negative polarity conduction time, resulting in forward rotation of the motor. A larger duty cycle leads to a longer positive polarity conduction time and a faster motor speed. When the PWM duty cycle is less than 50%, the negative polarity conduction time is greater than the positive polarity conduction time, resulting in reverse rotation of the motor. A smaller duty cycle leads to a longer negative polarity conduction time and a faster motor speed. When the PWM duty cycle is equal to 50%, the positive polarity conduction time is approximately equal to the negative polarity conduction time, and the motor stops.

[0062] The solution proposed in this application constructs a logic circuit that combines unipolar and bipolar control modes. Different control modes are selected by the states of the INA / INB and PWM pins. When the states of the INA and INB input pins are the same, the motor enters the braking mode or the PWM bipolar control mode. When the states of the INA and INB input pins are different, the original circuit control logic is retained, and the motor enters the unipolar control mode. At this time, the PWM pin can be used for speed regulation. The duty cycle of the input PWM signal can be used to set the speed of the motor. The larger the duty cycle, the faster the speed, and vice versa.

[0063] The solution proposed in this application adopts a control method that combines single and bipolar control. By setting the INA / INB / PWM pin status, the motor can operate in different modes under different application scenarios, ensuring the practicality of the motor and improving control efficiency.

[0064] To verify the effectiveness of the invention, a system simulation was performed.

[0065] Figure 11The figure shows the system simulation results of switching the motor from unipolar control mode to bipolar control for forward rotation. The horizontal axis represents time, and the vertical axis, from top to bottom, represents the voltage waveforms of the INA pin input signal, INB pin input signal, PWM signal, GHA gate output, GLA gate output, GHB gate output, and GLB gate output, as well as the current waveform I0 flowing through the motor. In the first 1ms, both INA and INB pins are low, corresponding to low levels for the ina and inb logic signals. At this time, the motor enters braking mode: HSA and HSB are off, LSA and LSB are on, and the current flowing through the motor is 0. Between 1ms and 2ms, the states of the INA and INB pins are set differently, and the motor enters unipolar control mode. Between 1ms and 1.5ms, the INA pin is set high, and the INB pin is set low, corresponding to a high level for the ina logic signal and a low level for the inb logic signal. HSA and LSB are on (PWM is always high), and HSB and LSA are off. The current flowing through the motor is positive, and the motor rotates forward. During the period of 1.5ms to 2ms, the INA pin is set to low and the INB pin is set to high. The corresponding INA logic signal is low and the INB logic signal is high. HSB and LSA are enabled (PWM is always high). HSA and LSB are disabled. The current flowing through the motor is negative and the motor reverses.

[0066] At 2ms, both INA and INB pins are set high, corresponding to high logic signals for INA and INB. At this point, the unipolar control mode is exited, and a bipolar mode controlled by the PWM pin is entered. During the period from 2ms to 2.1ms, the motor rotates forward because the PWM pin remains high. After 2.1ms, the PWM input is set to an 80% duty cycle, current flows from OUTA to OUTB, the average current is positive, and the motor continues to rotate forward. This invention, by setting the states of the INA / INB / PWM pins, allows the motor to operate in different modes under different application scenarios, ensuring the motor's practicality and improving control efficiency.

[0067] Figure 12 The figure shows the system simulation results of switching from unipolar control mode to bipolar control motor reversal. The horizontal axis represents time, and the vertical axis from top to bottom represents the voltage waveforms of the input signals of the INA and INB pins, the PWM signal, the gate outputs of GHA, GLA, GHB, and GLB, as well as the current waveform I0 flowing through the motor. The timing state for the first 2ms is the same as before. Figure 10Consistent. At 2ms, both INA and INB pins are set high, corresponding to high logic signals for INA and INB. At this point, the unipolar control mode exits and enters bipolar mode controlled by the PWM pin. During the period from 2ms to 2.1ms, since the PWM is constantly high, the average current is positive, and the motor rotates forward. After 2.1ms, the PWM is set to a 20% duty cycle input, current flows from OUTB to OUTA, the average current becomes negative, and the motor rotates in reverse.

[0068] Similar to a car's transmission, the system automatically selects the most suitable "drive gear" based on the actual operating needs of the DC motor (low speed, high torque vs. high speed, high power). The control method combining monopolar and bipolar drives typically involves using bipolar control at low speeds where precise control is required, and switching to monopolar control during high-speed, steady-state operation. This hybrid drive approach significantly improves performance across the entire speed range, achieving both low-speed smoothness and high-speed efficiency. It also optimizes motor energy efficiency and thermal management. When the motor operates at medium or high speeds most of the time, monopolar drive significantly reduces overall power consumption and temperature rise, avoiding the heat dissipation and reliability issues caused by the continuous high heat generation of bipolar drive, while also extending the battery life of battery-powered devices. Furthermore, it enhances system reliability by resulting in lower junction temperatures and less stress on power devices, thus greatly improving the long-term reliability of the drive circuit. Finally, it strikes a balance between cost and performance, achieving higher output capacity without increasing heat dissipation costs, making it a cost-effective solution from a system perspective.

[0069] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that the embodiments in this specification are not limited to the described order of actions, because according to the embodiments in this specification, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in this specification are all preferred embodiments, and the actions and modules involved are not necessarily essential to the embodiments in this specification.

[0070] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0071] The preferred embodiments disclosed above are merely illustrative of this specification. The optional embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the embodiments described herein. These embodiments are selected and specifically described in this specification to better explain the principles and practical applications of the embodiments, thereby enabling those skilled in the art to better understand and utilize this specification. This specification is limited only by the claims and their full scope and equivalents.

Claims

1. A method for driving a motor with hybrid single and bipolar polarity, characterized in that, include: Detect the logic state of the first control signal and the second control signal; When the logic states of the first control signal and the second control signal are different, the system enters a unipolar control mode. In this unipolar control mode, the direction of the motor is determined by the combination of the logic states of the first control signal and the second control signal, and the speed of the motor is controlled by the duty cycle of the pulse width modulation signal. When the logic states of the first control signal and the second control signal are the same, the system enters a bipolar control mode or a braking mode; wherein, the bipolar control mode or braking mode controls the direction and speed of the motor through the duty cycle of the pulse width modulation signal.

2. The control method according to claim 1, characterized in that, The bipolar control modes include: During one cycle of the pulse width modulation signal, the voltage across the motor is switched alternately between a positive power supply voltage and a negative power supply voltage. By controlling the duty cycle of the pulse width modulation signal, the ratio of the positive voltage application time to the negative voltage application time within one cycle is controlled, thereby controlling the direction and magnitude of the average voltage of the motor and realizing the forward rotation, reverse rotation or stop of the motor.

3. The control method according to claim 2, characterized in that: When the duty cycle of the pulse width modulation signal is greater than 50%, the motor rotates in the forward direction; When the duty cycle of the pulse width modulation signal is less than 50%, the motor reverses. When the duty cycle of the pulse width modulation signal is 50%, the average voltage of the motor is zero, and the motor is in a stopped state.

4. The control method according to claim 1, characterized in that, The braking mode is: When both the first control signal and the second control signal are at a low level, all high-side switches in the motor drive circuit are turned off, and all low-side switches are turned on, causing short-circuit braking at both ends of the motor.

5. A single- and bipolar hybrid drive circuit for implementing the control method according to any one of claims 1-4, characterized in that, include: A logic control unit is configured to receive the first control signal, the second control signal, and the pulse width modulation signal, and output a mode selection signal and a corresponding gate control logic signal. The gating unit, connected to the logic control unit, is used to select the gate drive control signal in either unipolar control mode or bipolar control mode according to the mode selection signal. The driving unit, connected to the gating unit, is used to generate and output gate driving voltages for controlling the turn-on or turn-off of each power switch in the H-bridge circuit according to the gate driving control signal.

6. The hybrid drive circuit according to claim 5, characterized in that, The logic control unit includes: The first logic module is used to generate a first set of control signals for the bipolar control mode based on the pulse width modulation signal; The second logic module is configured to generate a second set of control signals for a unipolar control mode based on the first control signal and the second control signal, and to generate the mode selection signal characterizing whether the logic states of the first control signal and the second control signal are the same.

7. The hybrid drive circuit according to claim 6, characterized in that, The first logic module includes: The first control sub-circuit is used to generate complementary signals for controlling the high-side and low-side switches of the first arm of the H-bridge according to the pulse width modulation signal. The second control sub-circuit is used to generate complementary signals for controlling the high-side and low-side switches of the second arm of the H-bridge based on the pulse width modulation signal.

8. The hybrid drive circuit according to claim 6, characterized in that, The second logic module includes: A signal conversion circuit is used to convert the external levels of the first control signal and the second control signal into internal logic levels; The logic operation circuit is used to perform an XOR operation on the logic levels of the converted first control signal and the second control signal, and output the mode selection signal.

9. The hybrid drive circuit according to claim 5, characterized in that, The gating unit includes multiple gating circuits, and each gating circuit corresponds to a switching transistor in the H-bridge circuit. Each of the aforementioned gating circuits is configured as follows: When the mode selection signal indicates a unipolar control mode, the corresponding control signal from the second logic module is output to the drive unit; When the mode selection signal indicates the bipolar control mode, the corresponding control signal from the first logic module is output to the drive unit.

10. The hybrid drive circuit according to any one of claims 5-9, characterized in that, The driving circuit is integrated into a chip, and the first control signal, the second control signal, and the pulse width modulation signal are connected through the input pins of the chip.

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