Wheelchair driving control circuit

Abstract

The invention discloses a wheelchair driving control circuit, which comprises a processor and a peripheral circuit thereof, a current driving circuit and a sampling circuit, and is characterized in that the processor and the peripheral circuit thereof comprise a main control chip, a first motor control chip and a second motor control chip; the current driving circuit comprises a first current driving circuit and a sampling amplifying circuit thereof, a second current driving circuit and a sampling amplifying circuit thereof, and a reference sampling circuit; the first motor control chip and the second motor control chip provide control signals for driving chips of the first motor and the second motor respectively, and the communication mode between the first motor control chip and the second motor control chip is serial communication. The main control chip is used for controlling the first motor control chip and the second motor control chip, and the communication mode is serial communication; in the sampling amplification circuit, the bias voltage of the same-direction end of an operational amplifier is 2.5 V.

Description

[0001] This application is a divisional application of the invention patent application with application number "202111286770.3", application date November 02, 2021, and invention name "A walking aid wheelchair drive control circuit". Technical Field

[0002] The present invention relates to the field of assistive devices and mobile walking aid technology, in particular to a walking aid wheelchair driving control circuit. Background Art

[0003] Existing electric walkers and electric wheelchairs all use motor drive in a single sampling mode. The motor speed cannot be switched according to different functions, the speed regulation is not intelligent, the control system is prone to failure, and the motor control is inaccurate and error-prone.

[0004] To this end, the present invention provides a drive control circuit for a walker wheelchair, which can make the control system of the walker wheelchair run stably and adapt to various complex road conditions. The circuit is stable and reliable, and the sampling circuit is efficient and accurate. It can move forward and backward and turn left and right according to the load of the user, assisting the user to move, and can meet the travel needs of various disabled people. Summary of the invention

[0005] In order to achieve the purpose of the present invention, the following technical solutions are adopted:

[0006] A walking aid wheelchair drive control circuit includes a processor and its peripheral circuits, a current drive circuit, and a sampling circuit, wherein: the processor and its peripheral circuits include a main control chip, a first motor control chip, and a second motor control chip; the current drive circuit includes a first current drive circuit and its sampling amplifier circuit, a second current drive circuit and its sampling amplifier circuit, and a reference sampling circuit; the sampling circuit includes a power supply voltage sampling circuit, a motor Hall sensor sampling circuit, and an encoder sampling circuit.

[0007] The walking aid wheelchair driving control circuit, wherein: the processor and its peripheral circuits include a main control chip, a first motor control chip and a second motor control chip; the first motor control chip and the second motor control chip provide control signals to the driving chips of the first motor and the second motor respectively, and the communication method between the first motor control chip and the second motor control chip is serial communication; the main control chip is used to control the first motor control chip and the second motor control chip, and the communication method is serial communication.

[0008] The walker wheelchair drive control circuit, wherein the pins of the first motor control chip U1 are connected as follows: pin 5 is connected to the first end of resistor R5, the second end of R5 is connected to the +5V voltage, pin 6 is connected to the first end of resistor R6, and the second end of R6 is connected to the digital ground DGND; pin 22 is connected to the DC1_ADC_IN4 end, pin 23 is connected to the DC1_ADC_IN5 end, pin 24 is connected to the DC1_ADC_IN6 end, pin 25 is connected to the DC1_ADC_IN7 end, and pin 26 is connected to the DC1_ADC C_IN8 terminal; pin 28 is connected to DC1_ADC_IN11 terminal, pin 34 is connected to DC1_PWDT_IN1 terminal; pin 35 is connected to DC1_PWDT_IN2 terminal,; pin 40 is connected to DC1_PWDT_IN0 terminal,; pin 36 is connected to DC1_UART1_TX terminal, pin 37 is connected to DC1_UART1_RX terminal; DC1_UART1_TX terminal and DC1_UART1_RX terminal are also connected to the first end of resistor R18 and resistor R19 respectively, The second ends of resistors R18 and R19 are connected to +5V voltage; pin 38 is connected to resistor R22, and the other end of resistor R22 is connected to digital ground DGND; pin 54 is connected to DC1_PWM2_CH0 end, pin 55 is connected to DC1_PWM2_CH1 end; pin 56 is connected to DC1_PWM2_CH2 end, pin 57 is connected to DC1_PWM2_CH3 end; pin 52 is connected to DC1_PWM2_CH4 end, pin 53 is connected to DC1_PWM2_CH5 end; pin 6 1 is connected to the first end of resistor R25, and the second end of resistor R25 is connected to the digital ground DGND; pin 62 and pin 64 are connected to DC1_SWCLK and DC1_SWDIO respectively; pin 78 is connected to the first end of resistor R15, and the second end of resistor R15 is connected to the digital ground DGND; pins 7 and 8 are connected to DC1_PWM1_CH0 and DC1_PWM1_CH1 respectively; pin 17 is connected to DC1_ADC_IN12; pin 39 is connected to DC1_PWM_FAULT1.

[0009] In the walking aid wheelchair driving control circuit, the pin connections of the second motor control chip U12 are as follows:

[0010] Pin 5 is connected to the first end of resistor R80, the resistance of R80 is 10K ohms, and the second end of R80 is connected to +5V voltage. Pin 6 is connected to the first end of resistor R81, the resistance of R81 is 10K ohms, and the second end of R81 is connected to digital ground DGND; Pin 22 is connected to port DC2_ADC_IN4, pin 23 is connected to port DC2_ADC_IN5, pin 24 is connected to port DC2_ADC_IN6, pin 25 is connected to port DC2_ADC_IN7, and pin 26 is connected to port DC2_ADC_IN8; Pin 28 Connecting port DC2_ADC_IN11; pin 34 connecting port DC2PWDT_IN1; pin 35 connecting port DC2_PWDT_IN2; pin 40 connecting port DC2_PWDT_IN0; pin 36 connecting to the signal transmitting end DC2_UART1_TX of the second motor, pin 37 connecting to the signal receiving end DC2_UART1_RX of the second motor, DC2_UART1_TX and DC2_UART1_RX are also connected to the first ends of resistors R93 and R94 respectively;

[0011] Pin 38 is connected to the first end of resistor R97; pin 54 is connected to DC2_PWM2_CH0, pin 55 is connected to DC2_PWM2_CH1; pin 56 is connected to DC2_PWM2_CH2, pin 57 is connected to DC2_PWM2_CH3; pin 52 is connected to DC2_PWM2_CH4, pin 53 is connected to DC2_PWM2_CH5; pin 61 is connected to the first end of resistor R100; pin 62 and pin 64 are connected to DC2_SWCLK and DC2 _SWDIO, DC2_SWCLK and DC2_SWDIO are the read and write ports of chip U12, which are connected to the programmer to read and write the chip; pin 78 is connected to the first end of resistor R90, the resistance of resistor R90 is 10K ohms, and the second end of resistor R90 is connected to the digital ground DGND; pins 7 and 8 are connected to DC2_PWM1_CH0 and DC2_PWM1_CH1 respectively; pin 17 is connected to DC2_ADC_IN12; pin 39 is connected to DC2_PWM_FAULT1.

[0012] The walker wheelchair drive control circuit, wherein: U20 is the main control chip, pin 1 is the power supply terminal, connected to the 0 ohm resistor R151 and then connected to the +3.3V voltage source; pin 2 is connected to the LED indicator signal PC13_LED; pin 3 is connected to the buzzer PC14_BEEP; pins 16 and 17 are used as serial port communication with the first motor, respectively connected to the DC1_UART1_RX terminal and the DC1_UART1_TX terminal through resistors R156 and R157; pins 42 and 43 are respectively connected to the DC1_UART1_RX terminal and the DC1_UART1_TX terminal through resistors R162 and R163 Connect to DC2_UART1_RX terminal and DC2_UART1_TX terminal; pin 5 is connected to the first end of 1M ohm resistor R154, the first end of 8M Hz crystal oscillator Y3, and the first end of 20pf capacitor C52; pin 6 is connected to the second end of 1M ohm resistor R154, the second end of 8M Hz crystal oscillator Y3, and the first end of 20pf capacitor C53; the second ends of capacitors C52 and C53 are connected to digital ground DGND; pins 12, 18, 28, 31, 63, 60, and 47 are connected to digital ground DGND; pin 48 is connected to a +3.3 volt voltage source. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is the control circuit diagram of the walker wheelchair;

[0014] Figure 2 It is the processor and its peripheral circuits;

[0015] Figure 3A is a current driving circuit 1;

[0016] Figure 3B is a current driving circuit 2;

[0017] Figure 4 It is a sampling amplifier circuit;

[0018] Figure 5 is the reference sampling circuit;

[0019] Figure 6 It is a logic comparison sampling circuit for motor current overcurrent signal;

[0020] Figure 7 It is a power supply voltage sampling signal circuit;

[0021] Figure 8 It is the motor Hall sensor sampling circuit and encoder sampling circuit. DETAILED DESCRIPTION

[0022] Below, combined with the attached Figure 1-8 Specific embodiments of the present invention are described in detail.

[0023] like Figure 1As shown, the walking aid wheelchair driving control circuit of the present invention includes a processor and its peripheral circuits, a current driving circuit, and a sampling circuit. Among them: the processor and its peripheral circuits include a main control chip, a first motor control chip, and a second motor control chip. The current driving circuit includes a first current driving circuit and its sampling amplifier circuit, a second current driving circuit and its sampling amplifier circuit, and a reference sampling circuit. The sampling circuit includes a power supply voltage sampling circuit, a motor Hall sensor sampling circuit, and an encoder sampling circuit.

[0024] Figure 2 The invention is a processor and its peripheral circuits, including a main control chip (STM32F103RCT6), a first motor control chip and a second motor control chip. The first motor control chip and the second motor control chip provide control signals to the drive chips of the first motor and the second motor respectively, and the communication mode between the first motor control chip and the second motor control chip is serial communication. The main control chip is used to coordinately control the first motor control chip and the second motor control chip and allocate control resources, and the communication mode between them is serial communication.

[0025] The first motor control chip U1 (AC7811-80), 80-pin chip. The U1 pin connection is as follows: pins 1-4 are suspended; pin 5 is connected to the first end of resistor R5, R5 resistance is 10K ohms, R5 second end is connected to +5V voltage source, pin 6 is connected to the first end of resistor R6, R6 resistance is 10K ohms, R6 second end is connected to digital ground DGND; pins 16, 18-21 are suspended; pin 22 is connected to DC1_ADC_IN4, pin 23 is connected to DC1_ADC_IN5, pin 24 is connected to DC1_ADC_IN6, pin 25 is connected to DC1_ADC_IN7, and pin 26 is connected to DC1_ADC_IN8. Pins 22-26 are analog sampling input terminals, which are used to receive the signal output to chip U1 by the U-phase current sampling signal terminal DC1_ADC_IN4 of the first motor, the value output to chip U1 by the V-phase current sampling output terminal DC1_ADC_IN5 of the first motor, the value output to chip U1 by the W-phase current sampling output terminal DC1_ADC_IN6 of the first motor, the value output to chip U1 by the total current sampling output terminal DC1_ADC_IN7 of the first motor, and the value output to chip U1 by the 24V power supply sampling terminal DC1_ADC_IN8 ; Pin 27 is suspended; Pin 28 is connected to the spare ADC sampling input terminal DC1_ADC_IN11 for easy testing; Pin 32 is suspended; Pin 34 is connected to the DC1_PWDT_IN1 terminal, which is the signal of the V-phase Hall sensor of the first motor after RC filtering and interference elimination; Pin 35 is connected to DC1_PWDT_IN2, which is the signal of the W-phase Hall sensor of the first motor after RC filtering and interference elimination; Pin 40 is connected to DC1_PWDT_IN0, which is the signal of the U-phase Hall sensor of the first motor after RC filtering and interference elimination.

[0026] Pin 36 is connected to the signal sending end DC1_UART1_TX of the first motor, and pin 37 is connected to the signal receiving end DC1_UART1_RX of the first motor. Pins 36 and 37 are serial communication interfaces between the first motor and the main control chip U20. DC1_UART1_TX and DC1_UART1_RX are also connected to the first ends of resistors R18 and R19, respectively. The resistance values ​​of resistors R18 and R19 are both 10K ohms, and the second ends of resistors R18 and R19 are connected to a +5V voltage source. The function of resistors R18 and R19 is to pull up and protect the port.

[0027] Pin 38 is connected to resistor R22, the resistance of resistor R22 is 10K ohms, and the other end of resistor R22 is connected to digital ground DGND. The function is to keep the port low level valid; pins 41, 45-49 are suspended; pin 54 is connected to the PWM logic high level input terminal DC1_PWM2_CH0 of motor 1 of U3 chip (IR2101), pin 55 is connected to the PWM logic low level input terminal DC1_PWM2_CH1 of motor 1 of U3 chip (IR2101), DC1_PWM2_CH0 and DC1_PWM2_CH1 are respectively the HIN and LIN terminals of driver chip U3 (IR2101S), which are the U-phase PWM control signals for controlling the first motor; pin 56 is connected to the PWM logic high level input terminal DC1_PWM2_CH2 of motor 1 of U4 chip (IR2101), pin 57 is connected to the P of motor 1 of U4 chip (IR2101) The WM logic low level input terminal DC1_PWM2_CH3, DC1_PWM2_CH2 and DC1_PWM2_CH3 are respectively the HIN and LIN terminals of the driver chip U4 chip (IR2101S), which are the V-phase PWM control signal for controlling the first motor; pin 52 is connected to the PWM logic high level input terminal DC1_PWM2_CH4 of motor 1 of the U6 chip (IR2101), and pin 53 is connected to the PWM logic low level input terminal DC1_PWM2_CH5 of motor 1 of the U6 chip (IR2101). DC1_PWM2_CH4 and DC1_PWM2_CH5 are the HIN and LIN terminals of the driver chip U6 chip (IR2101S), which are the W-phase PWM control signal for controlling the first motor.

[0028] Pins 58-60 are suspended. Pin 61 is connected to the first end of resistor R25, the resistance of resistor R25 is 10K ohms, and the second end of resistor R25 is connected to digital ground DGND. The function is to keep the port low level valid. Pins 5, 6 and 61 constitute the control mode selection of chip U1. Pin 5 is pulled up, and pins 6 and 61 are pulled down. At this time, chip U1 is in sinusoidal wave Hall control mode; pins 62 and 64 are connected to DC1_SWCLK and DC1_SWDIO respectively. DC1_SWCLK and DC1_SWDIO are the read and write ports of chip U1, and the programmer is connected to read and write the chip; pin 78 is connected to the first end of resistor R15. The resistance value of resistor R15 is 10K ohms. The second end of resistor R15 is connected to digital ground DGND, which is used to keep the port at a low level. Pins 38 and 78 are pulled down to detect abnormal PWM faults of chip U1, to avoid affecting the PWM output of the chip due to interference level signals, which affects the entire control circuit and ensures normal chip control operation.

[0029] Pins 7 and 8 are connected to DC1_PWM1_CH0 and DC1_PWM1_CH1 respectively. DC1_PWM1_CH0 and DC1_PWM1_CH1 are the A output and B output of the AB phase of the encoder of the first motor respectively. Pins 7 and 8 receive the signal of the encoder after the resistor-capacitor filter. Pin 17 is connected to DC1_ADC_IN12, which is the +5V voltage source sampling terminal; Pin 39 is connected to DC1_PWM_FAULT1, which is the PWM signal control terminal of the first motor. The chip works normally when the level is low. If DC1_PWM_FAULT1 is high, the PWM signal of the chip stops outputting. Other pins are all floating.

[0030] The second motor control chip U12 (AC7811-80) is an 80-pin chip. The pin connection of U12 is as follows: pins 1-4 are suspended, pin 5 is connected to the first end of resistor R80, R80 has a resistance of 10K ohms, and the second end of R80 is connected to a +5V voltage source, pin 6 is connected to the first end of resistor R81, R81 has a resistance of 10K ohms, and the second end of R81 is connected to the digital ground DGND; pins 16, 18-21 are suspended.

[0031] Pin 22 is connected to port DC2_ADC_IN4, pin 23 is connected to port DC2_ADC_IN5, pin 24 is connected to port DC2_ADC_IN6, pin 25 is connected to port DC2_ADC_IN7, and pin 26 is connected to port DC2_ADC_IN8. Pins 22-26 are analog sampling input terminals, which respectively receive the value output to chip U12 by U-phase current sampling output terminal DC2_ADC_IN4 of the second motor, the value output to chip U12 by V-phase current sampling output terminal DC2_ADC_IN5 of the second motor, the value output to chip U12 by W-phase current sampling output terminal DC2_ADC_IN6 of the second motor, the value output to chip U12 by total current sampling output terminal DC2_ADC_IN7 of the second motor, and the value output to chip U12 by 24V power supply sampling output terminal DC2_ADC_IN8.

[0032] Pin 27 is suspended; Pin 28 is connected to port DC2_ADC_IN11, which is the backup ADC sampling input; Pin 32 is suspended. Pin 34 is connected to port DC2PWDT_IN1, and receives the signal of the V-phase Hall sensor of the second motor after the RC filtering and interference elimination. Pin 35 is connected to port DC2_PWDT_IN2, and receives the signal of the W-phase Hall sensor of the second motor after the RC filtering and interference elimination. Pin 40 is connected to port DC2_PWDT_IN0, and receives the signal of the U-phase Hall sensor of the second motor after the RC filtering and interference elimination. Pin 36 is connected to the signal sending end DC2_UART1_TX of the second motor, and pin 37 is connected to the signal receiving end DC2_UART1_RX of the second motor. Pins 36 and 37 are the serial communication interface between the second motor and the main control chip U20. DC2_UART1_TX and DC2_UART1_RX are also connected to the first end of resistor R93 and resistor R94 respectively, the resistance of resistor R93 and resistor R94 are both 10K ohms, and the second end of resistor R93 and resistor R94 are connected to +5V voltage source. The function of resistor R93 and resistor R94 is to pull up and protect the port.

[0033] Pin 38 is connected to the first end of resistor R97, the resistance of resistor R97 is 10K ohms, and the second end of resistor R97 is connected to the digital ground DGND, which is used to keep the port valid at a low level; pins 41, 45-49 are suspended; pin 54 is connected to the PWM logic high level input terminal DC2_PWM2_CH0 of motor 2 of U14 chip (IR2101), and pin 55 is connected to the PWM logic low level input terminal DC2_PWM2_CH1 of motor 2 of U14 chip (IR2101). DC2_PWM2_CH0 and DC2_PWM2_CH1 are respectively the HIN and LIN terminals of U14 chip (IR2101S), which are the U-phase PWM control signals for controlling the second motor; pin 56 is connected to the PWM logic high level input terminal DC2_PWM2_CH2 of motor 2 of U15 chip (IR2101), and pin 57 is connected to the PWM logic low level input terminal DC2_PWM2_CH1 of motor 2 of U15 chip (IR2101). 7 is connected to the PWM logic low level input terminal DC2_PWM2_CH3 of motor 2 of U15 chip (IR2101), DC2_PWM2_CH2 and DC2_PWM2_CH3 are respectively the HIN and LIN terminals of U15 chip (IR2101S), which are the V-phase PWM control signal for controlling the second motor; pin 52 is connected to the PWM logic high level input terminal DC2_PWM2_CH4 of motor 2 of U17 chip (IR2101), pin 53 is connected to the PWM logic low level input terminal DC2_PWM2_CH5 of motor 2 of U17 chip (IR2101), DC2_PWM2_CH4 and DC2_PWM2_CH5 are respectively the HIN and LIN terminals of U17 chip (IR2101S), which are the W-phase PWM control signal for controlling the second motor; pins 58-60 are left floating.

[0034] Pin 61 is connected to the first end of resistor R100, the resistance of resistor R100 is 10K ohms, and the second end of resistor R100 is connected to the digital ground DGND, which is used to keep the port at a low level. Pins 5, 6 and 61 constitute the control mode selection of chip U12. Pin 5 is pulled up, and pins 6 and 61 are pulled down. At this time, chip U12 is in sinusoidal wave Hall control mode.

[0035] Pin 62 and pin 64 are connected to DC2_SWCLK and DC2_SWDIO respectively. DC2_SWCLK and DC2_SWDIO are the read and write ports of chip U12, and the programmer is connected to read and write the chip; pin 78 is connected to the first end of resistor R90, the resistance value of resistor R90 is 10K ohms, and the second end of resistor R90 is connected to the digital ground DGND, which is used to keep the port at a low level. Pins 38 and 78 are pulled down to prevent interference in the PWM fault detection of chip U12 and ensure normal chip control operation.

[0036] Pins 7 and 8 are connected to DC2_PWM1_CH0 and DC2_PWM1_CH1 respectively. DC2_PWM1_CH0 and DC2_PWM1_CH1 are the encoder output ports A and B of the second motor respectively. Pins 7 and 8 receive the encoder signal after RC filtering. Pin 17 is connected to DC2_ADC_IN12, which is the +5V voltage source sampling terminal. Pin 39 is connected to DC2_PWM_FAULT1, which is the PWM signal control terminal of the second motor. The chip works normally when the level is low. If DC2_PWM_FAULT1 is high, the chip PWM stops outputting. Other pins are left floating.

[0037] U20 is the main control chip (STM32F103RCT6), pin 1 is the power supply terminal, connected to 0 ohm resistor R151 and then connected to +3.3V voltage source. Pin 2 is connected to LED indicator signal PC13_LED, used to determine whether the chip is operating normally, pin 3 is connected to buzzer PC14_BEEP, used to send prompt sound; pins 16 and 17 are used as serial port communication with the first motor, connected to DC1_UART1_RX terminal and DC1_UART1_TX terminal through resistors R156 and R157 respectively, and the resistance values ​​of resistors R156 and R157 are both 1K ohms; pins 42 and 43 are used as serial port communication with the second motor, connected to DC2_UART1_R through resistors R162 and R163 respectively. X end, DC2_UART1_TX end, the resistance values ​​of resistors R162 and R163 are both 1K ohms; pin 5 is connected to the first end of 1M ohm resistor R154, the first end of 8M Hz crystal oscillator Y3, and the first end of 20pf capacitor C52, pin 6 is connected to the second end of 1M ohm resistor R154, the second end of 8M Hz crystal oscillator Y3, and the first end of 20pf capacitor C53, and the second ends of capacitors C52 and C53 are connected to digital ground DGND; pins 12, 18, 28, 31, 63, 60, and 47 are connected to digital ground DGND; pin 48 is connected to +3.3 volt voltage.

[0038] Figure 3 is a current driving circuit. Figure 3A and Figure 3B They are current driving circuits for the first motor and the second motor respectively.

[0039] Figure 3AIn the circuit, the PWM control signal of chip U1 is modulated into the control signal of driving MOS tube through the bootstrap boost inside the driver chip (U3, U4, U6); chip U3 is IR2101S, pin 1 of U3 is Vcc, power supply terminal, connected to +12V voltage source, pin 1 is connected to the first end of capacitor CB4, the capacitance of CB4 is 0.1μF / 50V, and the second end of CB4 is connected to digital ground DGND; pin 2 is HIN, high-end logic input terminal, connected to DC1_PWM2_C of chip U1 H0, pin 3 is LIN, the low-end logic input terminal, connected to DC1_PWM2_CH1 of U1 chip; pin 4 is COM, connected to digital ground DGNG; pin 5 is LO, the low-end output voltage terminal, connected to the first end of resistor R12, the resistance of R12 is 10 ohms, and the second end of R12 is connected to the 1st end (gate) of MOS tube QF2 (NEC6990); pin 6 is Vs, the high-side floating power supply compensation voltage terminal, connected to the U-phase terminal DC1_U of the first motor, and pin 6 is also connected to the first end of capacitor CB2, The capacitance of CB2 is 1μF / 100V. The second end of CB2 is connected to the cathode of diode D1. The function of CB2 is to boost the voltage and maintain the conduction of MOS tube. D1 is 1N4148. The anode of D1 is connected to 12V voltage source. Pin 7 is HO, high-side output voltage terminal, connected to the first end of resistor R10. The resistance of R10 is 10 ohms. The second end of R10 is connected to the 1 end (gate) of MOS tube QF1 (NCE6990). Pin 8 is high-side floating power supply voltage terminal, connected to the cathode of diode D1. The 2nd terminal (drain) of QF1 is connected to a +24V voltage source, the +24V voltage source is connected to a first terminal of an electrolytic capacitor CE1, CE1 is 220μF / 100V, and a second terminal of CE1 is connected to an analog ground GND; the +24V voltage source is also connected to a first terminal of a capacitor CB1, CB1 is 0.1μF / 100V, and a second terminal of CB1 is connected to a digital ground DGND; the 3rd terminal (source) of QF1 is connected to a U-phase terminal DC1_U of the first motor, and the 3rd terminal of QF1 is also connected to the 2nd terminal (drain) of QF2 and pin 6. The 3rd end (source) of QF2 is connected to the U-phase current sampling end DC1_I_U of the first motor, DC1_I_U is connected to the first end of the sampling resistor R17, R17 is a precision sampling resistor of 0.002 ohm, 1% accuracy, and 5W, the second end of R17 is connected to the UVW three-phase total current sampling bus DC1_I_BUS of the first motor, DC1_I_BUS is also connected to the first end of the sampling resistor R62, R62 is a precision sampling resistor of 0.002 ohm, 1% accuracy, and 5W, and the second end of R62 is connected to the analog ground GND.

[0040] Chip U4 is IR2101S. Pin 1 of U4 is Vcc, the power supply terminal, connected to a +12V voltage source. Pin 1 is connected to one end of capacitor CB11, the capacitance of CB11 is 0.1μF / 50V, and the other end of CB11 is connected to the digital ground DGND. Pin 2 is HIN, the high-end logic input terminal, connected to DC1_PWM2_CH2 of U1 chip. Pin 3 is LIN, the low-end logic input terminal, connected to DC1_PWM2_CH3 of U1 chip. Pin 4 is COM, connected to the digital ground DGNG. Pin 5 is LO, the low-end output voltage terminal, connected to the first end of resistor R30, the resistance of R30 is 10 ohms, and the second end of R30 is connected to the 1st end (gate) of MOS tube QF4 (NEC6990). Pin 6 is Vs, the high-side floating power supply compensation voltage terminal, connected to the V-phase terminal DC1_V of the first motor. Pin 6 is also connected to the first end of capacitor CB9, the capacitance of CB9 is 1μF / 100V, the second end of CB9 is connected to the cathode of diode D2, the function of CB9 is to bootstrap and boost the voltage to maintain the conduction of the MOS tube, D2 is 1N4148, and the positive electrode of D2 is connected to the 12V voltage source. Pin 7 is HO, the high-side output voltage terminal, connected to the first end of R27, the resistance of R27 is 10 ohms, and the second end of R27 is connected to the 1 end (gate) of MOS tube QF3 (NCE6990). Pin 8 is the high-side floating power supply voltage terminal, connected to the cathode of diode D2. The 2nd terminal (drain) of QF3 is connected to a +24V voltage source, which is connected to the first terminal of electrolytic capacitor CE2, which is 220μF / 100V, and the second terminal of CE2 is connected to analog ground GND; the +24V voltage source is also connected to the first terminal of capacitor CB7, which is 0.1μF / 100V, and the second terminal of CB7 is connected to digital ground DGND. The 3rd terminal (source) of QF3 is connected to the V-phase terminal DC1_V of the first motor, and the 3rd terminal of QF3 is also connected to the 2nd terminal (drain electrode) of QF4 and pin 6. The 3rd terminal (source) of QF4 is connected to the V-phase current sampling terminal DC1_I_V of the first motor, DC1_I_V is connected to the first terminal of the sampling resistor R38, R38 is a precision sampling resistor of 0.002 ohm, 1% accuracy, and 5W, the second terminal of R38 is connected to the total current sampling bus DC1_I_BUS of the first motor, DC1_I_BUS is also connected to the first terminal of the sampling resistor R62, R62 is a precision sampling resistor of 0.002 ohm, 1% accuracy, and 5W, and the second terminal of R62 is connected to the analog ground GND.

[0041] Chip U6 is IR2101S. Pin 1 of U6 is Vcc, the power supply terminal, connected to a +12V voltage source. Pin 1 is connected to the first end of capacitor CB16, the capacitance of CB16 is 0.1μF / 50V, and the second end of CB16 is connected to the digital ground DGND. Pin 2 is HIN, the high-end logic input terminal, connected to DC1_PWM2_CH4 of the U6 chip. Pin 3 is LIN, the low-end logic input terminal, connected to DC1_PWM2_CH5 of the U6 chip. Pin 4 is COM, connected to the digital ground DGNG. Pin 5 is LO, the low-end output voltage terminal, connected to the first end of resistor R56, the resistance of R56 is 10 ohms, and the second end of R56 is connected to the 1st end (gate) of MOS tube QF6 (NEC6990). Pin 6 is Vs, the high-side floating power supply compensation voltage terminal, connected to the W-phase terminal DC1_W of the first motor. Pin 6 is also connected to the first end of capacitor CB15, the capacitance of CB15 is 1μF / 100V, and the second end of CB15 is connected to the cathode of diode D3. The function of CB15 is to boost the voltage and maintain the conduction of the MOS tube. D3 is 1N4148, and the positive pole of D3 is connected to the 12V voltage source. Pin 7 is HO, the high-side output voltage terminal, connected to the first end of R55, the resistance of R55 is 10 ohms, and the second end of R55 is connected to the 1 end (gate) of MOS tube QF5 (NCE6990). Pin 8 is the high-side floating power supply voltage terminal, connected to the cathode of diode D3. The 2nd terminal (drain) of QF5 is connected to a +24V voltage source, which is connected to one end of electrolytic capacitor CE3, which is 220μF / 100V, and the other end of CE3 is connected to analog ground GND; the +24V voltage source is also connected to one end of capacitor CB14, which is 0.1μF / 100V, and the other end of CB14 is connected to digital ground DGND. The 3rd terminal (source) of QF5 is connected to the W phase terminal DC1_W of the first motor, and the 3rd terminal of QF5 is also connected to the 2nd terminal (drain) of QF6. The 3rd end (source) of QF6 is connected to the W-phase current sampling end DC1_I_W of the first motor, DC1_I_W is connected to the first end of the sampling resistor R60, R60 is a precision sampling resistor of 0.002 ohm, 1% accuracy, and 5W, the second end of R60 is connected to the three-phase total current sampling bus DC1_I_BUS of the first motor, DC1_I_BUS is also connected to the first end of the sampling resistor R62, R62 is a precision sampling resistor of 0.002 ohm, 1% accuracy, and 5W, and the second end of R62 is connected to the analog ground GND.

[0042] Figure 3B In the circuit, the PWM control signal of the chip U12 is modulated into a control signal for driving the MOS tube through the bootstrap boost inside the driver chip (U14, U15, U17).

[0043] Chip U14 is IR2101S. Pin 1 of U14 is Vcc, the power supply terminal, connected to a +12V voltage source. Pin 1 is connected to the first end of capacitor CB27, the capacitance of CB27 is 0.1μF / 50V, and the second end of CB27 is connected to the digital ground DGND. Pin 2 is HIN, the high-end logic input terminal, connected to DC2_PWM2_CH0 of the U12 chip. Pin 3 is LIN, the low-end logic input terminal, connected to DC2_PWM2_CH1 of the U12 chip. Pin 4 is COM, connected to the digital ground DGNG. Pin 5 is LO, the low-end output voltage terminal, connected to the first end of resistor R87, the resistance of R87 is 10 ohms, and the second end of R87 is connected to the 1st end (gate) of the MOS tube QF8 (NEC6990). Pin 6 is Vs, the high-side floating power supply compensation voltage terminal, connected to the U-phase terminal DC2_U of the second motor. Pin 6 is also connected to the first end of capacitor CB25, the capacitance of CB25 is 1μF / 100V, the second end of CB2 is connected to the cathode of diode D7, the function of CB25 is to bootstrap and boost the voltage to maintain the conduction of the MOS tube, D7 is 1N4148, and the positive electrode of D7 is connected to the 12V voltage source. Pin 7 is HO, the high-side output voltage terminal, connected to one end of resistor R85, the resistance of R85 is 10 ohms, and the other end of R85 is connected to the 1 end (gate) of MOS tube QF7 (NCE6990). Pin 8 is the high-side floating power supply voltage terminal, connected to the cathode of diode D7. The 2nd terminal (drain) of QF7 is connected to a +24V voltage source, which is connected to the first terminal of electrolytic capacitor CE4, which is 22-μF / 100V, and the second terminal of CE4 is connected to analog ground GND; the +24V voltage source is also connected to the first terminal of capacitor CB24, which is 0.1μF / 100V, and the second terminal of CB24 is connected to digital ground DGND. The 3rd terminal (source) of QF7 is connected to the U-phase terminal DC2_U of the second motor, and the 3rd terminal (source) of QF7 is also connected to the 2nd terminal (drain) of QF8 and pin 6. The 3rd end (source) of QF8 is connected to the U-phase current sampling end DC2_I_U of the second motor, DC2_I_U is connected to the first end of the sampling resistor R92, R92 is a precision sampling resistor of 0.002 ohm, 1% accuracy, 5W, the second end of R92 is connected to the total current sampling bus DC2_I_BUS of the second motor, DC2_I_BUS is also connected to the sampling resistor R137, R137 is a precision sampling resistor of 0.002 ohm, 1% accuracy, 5W, the other end of R62 is connected to the analog ground GND.

[0044] Chip U15 is IR2101S. Pin 1 of U15 is Vcc, the power supply terminal, connected to a +12V voltage source. Pin 1 is connected to the first end of capacitor CB34, the capacitance of CB34 is 0.1μF / 50V, and the second end of CB34 is connected to the digital ground DGND. Pin 2 is HIN, the high-end logic input terminal, connected to DC2_PWM2_CH2 of the U12 chip. Pin 3 is LIN, the low-end logic input terminal, connected to DC2_PWM2_CH3 of the U12 chip. Pin 4 is COM, connected to the digital ground DGNG. Pin 5 is LO, the low-end output voltage terminal, connected to the first end of resistor R105, the resistance of R105 is 10 ohms, and the second end of R105 is connected to the 1st end (gate) of MOS tube QF10 (NEC6990). Pin 6 is Vs, the high-side floating power supply compensation voltage terminal, connected to the V-phase terminal DC2_V of the second motor. Pin 6 is also connected to the first end of capacitor CB32, the capacitance of CB32 is 1μF / 100V, and the second end of CB32 is connected to the cathode of diode D8. The function of CB32 is to boost the voltage and maintain the conduction of the MOS tube. D8 is 1N4148, and the positive electrode of D8 is connected to the 12V voltage source. Pin 7 is HO, the high-side output voltage terminal, connected to one end of resistor R102, the resistance of R102 is 10 ohms, and the other end of R102 is connected to the 1 end (gate) of MOS tube QF9 (NCE6990). Pin 8 is the high-side floating power supply voltage terminal, connected to the cathode of diode D8. The 2nd terminal (drain) of QF9 is connected to a +24V voltage source, which is connected to the first terminal of electrolytic capacitor CE5, which is 22-μF / 100V, and the second terminal of CE5 is connected to analog ground GND; the +24V voltage source is also connected to the first terminal of capacitor CB30, which is 0.1μF / 100V, and the second terminal of CB30 is connected to digital ground DGND. The 3rd terminal (source) of QF9 is connected to the V-phase terminal DC2_V of the first motor, and the 3rd terminal of QF9 is also connected to the 2nd terminal (drain) of QF10 and pin 6. The 3rd terminal (source) of QF10 is connected to the V-phase current sampling DC2_I_V of the second motor, DC2_I_V is connected to the first terminal of the sampling resistor R113, R113 is a precision sampling resistor of 0.002 ohm, 1% accuracy, 5W, the other terminal of R113 is connected to the total current sampling DC2_I_BUS of the second motor, DC2_I_BUS is also connected to the first terminal of the sampling resistor R137, R137 is a precision sampling resistor of 0.002 ohm, 1% accuracy, 5W, the second terminal of R137 is connected to the analog ground GND.

[0045] Chip U17 is IR2101S. Pin 1 of U17 is Vcc, the power supply terminal, connected to a +12V voltage source. Pin 1 is connected to the first end of capacitor CB39, the capacitance of CB39 is 0.1μF / 50V, and the second end of CB39 is connected to the digital ground DGND. Pin 2 is HIN, the high-end logic input terminal, connected to DC2_PWM2_CH4 of the U12 chip. Pin 3 is LIN, the low-end logic input terminal, connected to DC2_PWM2_CH5 of the U12 chip. Pin 4 is COM, connected to the digital ground DGNG. Pin 5 is LO, the low-end output voltage terminal, connected to the first end of resistor R131, the resistance of R131 is 10 ohms, and the second end of R131 is connected to the 1st end (gate) of MOS tube QF12 (NEC6990). Pin 6 is Vs, the high-side floating power supply compensation voltage terminal, connected to the W-phase terminal DC2_W of the second motor. Pin 6 is also connected to the first end of capacitor CB38, the capacitance of CB38 is 1μF / 100V, and the second end of CB38 is connected to the cathode of diode D9. The function of CB138 is to boost the voltage and maintain the conduction of the MOS tube. D9 is 1N4148, and the positive electrode of D9 is connected to the 12V voltage source. Pin 7 is HO, the high-side output voltage terminal, connected to the first end of resistor R130, the resistance of R130 is 10 ohms, and the second end of R130 is connected to the 1 end (gate) of MOS tube QF11 (NCE6990). Pin 8 is the high-side floating power supply voltage terminal, connected to the cathode of diode D9. The 2nd terminal (drain) of QF11 is connected to a +24V voltage source, which is connected to the first terminal of electrolytic capacitor CE6, which is 22-μF / 100V, and the second terminal of CE6 is connected to analog ground GND; the +24V voltage source is also connected to the first terminal of capacitor CB37, which is 0.1μF / 100V, and the second terminal of CB37 is connected to digital ground DGND. The 3rd terminal (source) of QF11 is connected to the W-phase terminal DC2_W of the second motor, and the 3rd terminal of QF11 is also connected to the 2nd terminal (drain) of QF12 and pin 6. The 3rd end (source) of QF12 is connected to the W-phase current sampling DC2_I_W of the second motor, DC2_I_W is connected to the first end of the sampling resistor R135, R135 is a precision sampling resistor of 0.002 ohm, 1% accuracy, 5W, the second end of R135 is connected to the three-phase total current sampling DC2_I_BUS of the second motor, DC2_I_BUS is also connected to the sampling resistor R137, R137 is a precision sampling resistor of 0.002 ohm, 1% accuracy, 5W, the other end of R137 is connected to the analog ground GND.

[0046] Figure 3A , Figure 3BThe sampling resistor should be as small as possible so as not to affect the resistance of each phase of the motor, because the resistance of the motor phase resistance will directly participate in the foc calculation. However, it cannot be infinitely small. Too small is not conducive to obtaining current changes. It should also be selected according to the maximum working current of the design. This resistor is 0.002 / 5W. Theoretically, the maximum working current is 50A. The circuit design exceeds the maximum value of 10A, leaving enough margin to ensure the service life of the circuit and components.

[0047] Figure 4 It is a sampling amplifier circuit, which amplifies the sampling current signal by 12 times and inputs the amplified signal to the driver chip.

[0048] U2A is a MCP6022 chip. Terminal 2 (negative input terminal) is connected to the first terminal of resistor R3, R3 is 1K ohm 1%, terminal 2 is also connected to the first terminal of resistor R1, R1 is 24K ohm 1% (% indicates accuracy), the second terminal of R1 is connected to terminal 1 (output terminal) of U2A, the second terminal of R3 is connected to the first terminal of resistor R2 and capacitor CB3, R2 is 1K ohm 1%, the second terminal of R2 is connected to the three-phase total current sampling DC1_I_BUS of the first motor, C B3 is 68pF / 16V, the second end of CB3 is connected to the first end of resistors R8 and R11, R8 and R11 are 1K ohm 1%, the second end of R8 is connected to the U-phase total current sampling DC1_I_U of the first motor, the second end of R11 is connected to the 3 end (positive input end) of U2A, the 3 end (positive input end) of U2A is also connected to the first end of resistor R13, R13 is 24K ohm 1%, the second end of R13 is connected to the reference end DC1_OP_REF. The 1 end (output end) of U2A is connected to the second end of resistor R1 and the first end of resistor R7, R7 is 1K ohm, the second end of R7 is connected to the U-phase current ADC sampling port DC1_ADC_IN4 of the first motor and the first end of capacitor CB5, the capacitance of CB5 is 1nF / 16V, and the second end of CB5 is connected to the digital ground.

[0049] U2B is MCP6022, and the 6th terminal (negative input terminal) is connected to the first terminal of resistor R21, R21 is 1K ohm 1%, and the 6th terminal is also connected to the first terminal of resistor R16, R16 is 24K ohm 1%, and the second terminal of R16 is connected to the 7th terminal (output terminal) of U2B, and the second terminal of R21 is connected to the first terminal of resistor R20 and capacitor CB8, R20 is 1K ohm 1%, and the second terminal of R20 is connected to the three-phase total current sampling DC1_I_BUS of the first motor, CB8 The second end of CB8 is connected to the first end of resistors R24 and R26, R24 and R26 are 1K ohm 1%, the second end of R24 is connected to the V-phase total current sampling DC1_I_U of the first motor, the second end of R26 is connected to the 3-terminal (positive input terminal) of U2B, the 5-terminal (positive input terminal) of U2B is also connected to the first end of resistor R28, R28 is 24K ohm 1%, and the second end of R28 is connected to the reference terminal DC1_OP_REF. The 7-terminal (output terminal) of U2B is also connected to the second end of resistor R16 and the first end of resistor R23, R23 is 1K ohm, the second end of R23 is connected to the V-phase current ADC sampling port DC1_ADC_IN5 of the first motor and the first end of capacitor CB10, the capacitance of CB10 is 1nF / 16V, and the second end of CB10 is connected to the digital ground.

[0050] U5A is MCP6022, and the 2nd terminal (negative input terminal) is connected to the first terminal of resistor R37, R37 is 1K ohm 1%, and the 2nd terminal is also connected to the first terminal of resistor R33, R33 is 24K ohm 1%, and the second terminal of R33 is connected to the 1st terminal (output terminal) of U5A, and the second terminal of R37 is connected to the first terminal of resistor R36 and capacitor CB12, R36 is 1K ohm 1%, and the second terminal of R36 is connected to the three-phase total current sampling DC1_I_BUS of the first motor, CB 12 is 68pF / 16V, the second end of CB12 is connected to the first end of R41 and R44, R41 and R44 are 1K ohm 1%, the second end of R41 is connected to the W-phase total current sampling DC1_I_U of the first motor, the second end of R44 is connected to the 3 end (positive input end) of U5A, the 3 end (positive input end) of U5A is also connected to the first end of resistor R49, R49 is 24K ohm 1%, the second end of R49 is connected to the reference end DC1_OP_REF. The 1 end (output end) of U5A is also connected to the second end of resistor R33 and the first end of resistor R39, R39 is 1K ohm, the second end of R39 is connected to the W-phase current ADC sampling port DC1_ADC_IN4 of the first motor and the first end of capacitor CB13, the capacitance of CB13 is 1nF / 16V, and the second end of CB13 is connected to the digital ground.

[0051] U13A is MCP6022, and the 2nd terminal (negative input terminal) is connected to the first terminal of resistor R78, R78 is 1K ohm 1%, and the 2nd terminal is also connected to the first terminal of resistor R76, R76 is 24K ohm 1%, and the second terminal of R76 is connected to the 1st terminal (output terminal) of U13A, and the second terminal of R78 is connected to the first terminal of resistor R77 and capacitor CB26, R77 is 1K ohm 1%, and the second terminal of R77 is connected to the three-phase total current sampling DC2_I_BUS of the second motor, CB2 6 is 68pF / 16V, the second end of CB26 is connected to the first end of resistors R83 and R86, R83 and R86 are 1K ohm 1%, the second end of R83 is connected to the U-phase total current sampling DC2_I_U of the second motor, the second end of R86 is connected to the 3 end (positive input end) of U13A, the 3 end (positive input end) of U13A is also connected to the first end of resistor R88, R88 is 24K ohm 1%, the second end of R88 is connected to the reference end DC2_OP_REF. The 1 end (output end) of U13A is also connected to the second end of resistor R76 and the first end of resistor R82, R82 is 1K ohm, the second end of R82 is connected to the U-phase current ADC sampling port DC2_ADC_IN4 of the second motor and the first end of capacitor CB28, the capacitance of CB28 is 1nF / 16V, and the second end of CB28 is connected to the digital ground.

[0052] U13B is MCP6022, and the 6th terminal (negative input terminal) is connected to the first terminal of resistor R96, R96 is 1K ohm 1%, and the 6th terminal is also connected to the first terminal of resistor R91, R91 is 24K ohm 1%, and the second terminal of R91 is connected to the 7th terminal (output terminal) of U2B, and the second terminal of R96 is connected to the first terminal of resistor R95 and capacitor CB31, R95 is 1K ohm 1%, and the second terminal of R95 is connected to the three-phase total current sampling DC2_I_BUS of the second motor, and CB31 is 68 pF / 16V, the second end of CB31 is connected to the first end of resistors R101 and R99, R101 and R99 are 1K ohm 1%, the second end of R99 is connected to the V-phase total current sampling DC2_I_U of the second motor, the second end of R101 is connected to the 3rd end (positive input end) of U13B, the 5th end (positive input end) of U13B is also connected to the first end of resistor R103, R103 is 24K ohm 1%, the second end of R103 is connected to the reference end DC2_OP_REF. The 7th end (output end) of U13B is also connected to the second end of resistor R91 and the first end of resistor R98, R98 is 1K ohm, the second end of R98 is connected to the V-phase current ADC sampling port DC2_ADC_IN5 of the second motor and the first end of capacitor CB33, the capacitance of CB33 is 1nF / 16V, and the second end of CB33 is connected to the digital ground.

[0053] U16A is MCP6022, and the 2nd terminal (negative input terminal) is connected to the first terminal of resistor R112, R112 is 1K ohm 1%, and the 2nd terminal is also connected to the first terminal of resistor R108, R108 is 24K ohm 1%, and the second terminal of R108 is connected to the 1st terminal (output terminal) of U16A, and the second terminal of R112 is connected to the first terminal of resistor R111 and capacitor CB35, R111 is 1K ohm 1%, and the second terminal of R111 is connected to the three-phase total current sampling DC2_I_BUS of the second motor, CB3 5 is 68pF / 16V, the second end of CB35 is connected to the first end of resistors R119 and R116, R119 and R116 are 1K ohm 1%, the second end of R116 is connected to the W-phase total current sampling DC2_I_U of the second motor, the second end of R119 is connected to the 3 end (positive input end) of U16A, the 3 end (positive input end) of U16A is also connected to the first end of resistor R124, R124 is 24K ohm 1%, the second end of R124 is connected to the reference end DC2_OP_REF. The 1 end (output end) of U16A is also connected to the second end of resistor R108 and the first end of resistor R114, R114 is 1K ohm, the second end of R114 is connected to the W-phase current ADC sampling port DC2_ADC_IN4 of the second motor and the first end of capacitor CB36, the capacitance of CB36 is 1nF / 16V, and the second end of CB36 is connected to the digital ground.

[0054] Figure 4 The design idea of ​​the circuit is that in the motor phase current sampling circuit, the bias voltage of the inverting end of the operational amplifier is 2.5V, so that the value collected by the ADC minus 2.5V is the actual current value, because the ADC collects the most accurate data at the midpoint of the working range. Regarding the amplification factor, when the maximum current is designed, the input voltage of the current acquisition ADC cannot be greater than 5V. If it is greater than 5V, it will exceed the range and cause chip damage. Therefore, it is necessary to ensure that the amplification factor is large enough and that the ADC does not exceed the chip sampling range at the maximum current value.

[0055] Figure 5 For the reference sampling circuit.

[0056] U5B is MCP6022, terminal 6 (negative input terminal) is connected to terminal 7 (output terminal), terminal 5 (positive input terminal) is connected to two voltage-dividing resistors R57 and R61 and the first terminal of filter capacitor CB18, R57 and R61 are 10K ohm 1%, CB18 is 0.1μF / 16V, the second terminal of R57 is connected to +5V voltage source, and the second terminals of R61 and CB18 are connected to digital ground. Terminal 7 (output terminal) is also connected to the first terminal of resistor R58, R58 is 0 ohm, and the other terminal of R58 is connected to the current comparator reference voltage DC1_OP_REF of the first motor and the first terminal of filter capacitor CB17, CB17 is 0.1μF / 16V, and the second terminal of CB17 is connected to digital ground.

[0057] U16B is MCP6022, terminal 6 (negative input terminal) is connected to terminal 7 (output terminal), terminal 5 (positive input terminal) is connected to two voltage-dividing resistors R132 and R136 and the first terminal of filter capacitor CB41, R132 and R136 are 10K ohm 1%, CB41 is 0.1μF / 16V, the second terminal of R132 is connected to +5V voltage source, R136 and the second terminal of CB41 are connected to digital ground. Terminal 7 (output terminal) is also connected to the first terminal of resistor R133, R133 is 0 ohm, the second terminal of R133 is connected to the current comparator reference voltage DC2_OP_REF of the second motor and the first terminal of filter capacitor CB40, CB40 is 0.1μF / 16V, and the second terminal of CB40 is connected to digital ground.

[0058] Figure 6 It is a logic comparison sampling circuit for motor current overcurrent signal.

[0059] U11 is the first operational amplifier (MCP6021), pin 1 is the output terminal, pin 2 is connected to the digital ground, pin 3 is the positive input terminal, pin 4 is the negative input terminal, and pin 5 is the power supply terminal, connected to the +5V voltage source. Pin 3 is connected to the first end of resistor R74, R74 is 1K 1%, the second end of R74 is connected to resistor R73 and the first end of filter capacitor CB20, R73 is 1K 1%, CB20 is 68pF / 16V, and the second end of R73 is connected to the three-phase bus sampling current signal DC1_I_BUS of the first motor. Pin 4 is connected to the first end of resistor R69 and R64, R69 is 1K 1%, R64 is 24K 1%, the second end of R69 is connected to the second end of capacitor CB20 and the first end of resistor R68, R68 is 1K 1%, and the second end of R68 is connected to the analog ground. Pin 1 is connected to the second end of resistor R64 and the first end of resistor R71, R71 is 1K ohm, the second end of R71 is connected to filter capacitor CB21, the first end of resistor R72 and the sampling signal end DC1_ADC_IN7 of the motor three-phase bus current of the first motor, CB21 is 1nF / 16V, R72 is 1K ohm. The second end of CB21 is connected to the digital ground.

[0060] U10 is the second operational amplifier comparator (LMV7235), pin 1 is the output terminal, pin 2 is connected to the digital ground, pin 3 is the positive input terminal, pin 4 is the negative input terminal, and pin 5 is the power supply terminal, +5V voltage source. Pin 4 is connected to the second end of R72 and the first end of the filter capacitor CB22, CB22 is 68pF / 16V, and the second section of CB22 is connected to the digital ground. Pin 3 is connected to the first end of resistor R65 and resistor 66. Resistor R65 is 24K 1% and resistor R66 is 4.7K 1%. The second end of R65 is connected to the digital ground, and the second end of R66 is connected to the +5V voltage source. There is a filter capacitor CB19 between the +5V voltage source and the digital ground. CB19 is 0.1μF / 16V. Pin 1 is connected to the first end of the 0 ohm resistor R70, and the second end of R70 is connected to the PWM signal control terminal DC1_PWM_FAULT1 of the first motor. DC1_PWM_FAULT1 is also connected to the pull-up resistor R67 and the first end of the filter capacitor CB23, R67 is 10K ohms, CB23 is 0.01μF / 16V, the second end of R67 is connected to the +5V voltage source, and the second end of CB23 is connected to the digital ground.

[0061] The working principle of this circuit is as follows: U10 is the second operational amplifier comparator (LMV7235). The second operational amplifier is a comparator. Pin 3 uses resistors R65 (24K 1%) and 66 (4.7K 1%) to divide the +5V voltage source. If the current signal DC1_I_BUS is too large, the output signal DC1_ADC_IN7 of the first operational amplifier is larger than the +5V voltage divided by resistors R65 (24K 1%) and 66 (4.7K 1%), the output of the second operational amplifier comparator is reversed, the DC1_PWM_FAULT1 signal changes, and the control chip determines that the motor bus current is too large, and takes PWM signal protection measures after overcurrent.

[0062] U19 is the third operational amplifier (MCP6021), pin 1 is the output end, pin 2 is connected to the digital ground, pin 3 is the positive input end, pin 4 is the negative input end, and pin 5 is the power supply end, connected to the +5V voltage source. Pin 3 is connected to the first end of resistor R149, R149 is 1K 1%, the second end of R149 is connected to resistor R148 and the first end of filter capacitor CB43, R148 is 1K 1%, CB43 is 68pF / 16V, the second end of R148 is connected to the three-phase bus sampling current signal DC2_I_BUS of the second motor, pin 4 is connected to the first end of resistor R144 and R139, R144 is 1K 1%, R139 is 24K 1%, the second end of R144 is connected to the second end of capacitor CB43 and the first end of resistor R143, R143 is 1K 1%, and the second end of R143 is connected to the analog ground. Pin 1 is connected to the second end of resistor R139 and the first end of resistor R146, R46 is 1K ohm, the second end of R146 is connected to filter capacitor CB44, the first end of resistor R47 and the sampling signal end DC2_ADC_IN7 of the motor three-phase bus current of the second motor, CB44 is 1nF / 16V, R147 is 1K ohm. The second end of CB44 is connected to the digital ground.

[0063] U18 is the fourth operational amplifier comparator (LMV7235), pin 1 is the output end, pin 2 is connected to the digital ground, pin 3 is the positive input end, pin 4 is the negative input end, and pin 5 is the power supply end, connected to the +5V voltage source. Pin 4 is connected to the second end of R147 and the first end of the filter capacitor CB45, CB45 is 68pF / 16V, and the second end of CB45 is connected to the digital ground. Pin 3 is connected to the first end of the resistor R140 and the resistor 141, the resistor R140 is 24K ohm 1%, the resistor R141 is 4.7K ohm 1%, the second end of R140 is connected to the digital ground, and the second end of R141 is connected to the +5V voltage source. There is a filter capacitor CB42 between the +5V voltage source and the digital ground, and CB42 is 0.1μF / 16V. Pin 1 is connected to the first end of the 0 ohm resistor R145, and the second end of R145 is connected to the PWM signal control terminal DC2_PWM_FAULT1 of the second motor. DC2_PWM_FAULT1 is also connected to the pull-up resistor R142 and the first end of the filter capacitor CB46, R142 is 10K ohms, CB46 is 0.01μF / 16V, the second end of R142 is connected to the +5V voltage source, and the second end of CB46 is connected to the digital ground.

[0064] The working principle of this circuit is as follows: U18 is the fourth operational amplifier comparator (LMV7235). The second operational amplifier is a comparator. Pin 3 uses resistors R140 (24K 1%) and 141 (4.7K 1%) to divide the +5V voltage source. If the current signal DC2_I_BUS is too large, the output signal DC2_ADC_IN7 of the first operational amplifier is larger than the +5V voltage divided by resistors R140 (24K 1%) and 141 (4.7K 1%), the output of the second operational amplifier comparator is reversed, the DC2_PWM_FAULT1 signal changes, and the control chip determines that the motor bus current is too large, and takes PWM signal protection measures after overcurrent.

[0065] Figure 6 The design idea of ​​the circuit is that in the motor bus current sampling, the bias voltage of the same-direction end of the operational amplifier is 2.5V, just like the motor phase current sampling circuit. In this way, the value collected by the ADC minus 2.5V is the actual current value, because the ADC is most accurate when it is collected at the midpoint of the working range. The difference is that the former operational amplifier amplifies the bus (DC1_I_BUS, DC2_I_BUS) current to obtain the sampled value of the bus current. The latter is a comparator, which is used to determine whether the motor bus current is too large. When the bus current exceeds the range, it automatically stops the PWM output, thereby providing a protection measure.

[0066] Figure 7 It is the power supply voltage sampling signal circuit. Figure 7 The upper middle picture shows motor 1, and the lower picture shows motor 2.

[0067] DC1_ADC_IN8 is the +24V power supply voltage sampling signal output terminal. The working principle is that the +24V voltage source is divided by the resistors R4 and R9 in series and R14, R200, and R201 in parallel, and then filtered by the filter capacitor CB6 to obtain the sampling signal. CB6 is generally a 0.1μF capacitor, R4 is 49.9K 1%, R9 is 100 1%, R14 is 10K 1%, R200 is 5.1K 1%, and R201 is 10K 1%. The voltage divider circuit with multiple resistors in series and parallel can effectively protect the circuit when the power supply voltage is high and unstable. After calculation, the DC1_ADC_IN8 signal is about 2.2V.

[0068] DC2_ADC_IN8 is the +24V power supply voltage sampling signal. The working principle is that the +24V voltage source is divided by the resistors R79 and R84 in series and R89, R202, and R203 in parallel, and then filtered by the filter capacitor CB29 to obtain the sampling signal. CB29 is generally a 0.1μF capacitor, R79 is 49.9K 1%, R84 is 100 1%, R894 is 10K 1%, R202 is 5.1K 1%, and R203 is 10K 1%. The voltage divider circuit with multiple resistors in series and parallel can effectively protect the circuit when the power supply voltage is high and unstable. After calculation, the DC2_ADC_IN8 signal is about 2.2V.

[0069] Figure 8 It is the motor Hall sensor sampling circuit and encoder sampling circuit.

[0070] DC1_H_U, DC1_H_V, DC1_H_W are the U, V, W phase Hall sensor signals of the first motor respectively, and DC1_E-PWM1, DC1_E-PWM0 are the AB phase signals of the first motor encoder respectively.

[0071] The resistor R29 is 560 ohms, the resistor R31 is 1K ohms, the capacitor C9 is 0.01 μF, and DC1_PWDT_IN0 is the U-phase Hall sensor signal of the first motor, which is input to the first motor control chip U1 after resistance-capacitance filtering.

[0072] The resistor R34 is 560 ohms, the resistor R35 is 1K ohms, the capacitor C15 is 0.01 μF, and DC1_PWDT_IN1 is the V-phase Hall sensor signal of the first motor, which is input to the first motor control chip U1 after being filtered by resistors and capacitors.

[0073] The resistor R40 is 560 ohms, the resistor R42 is 1K ohms, the capacitor C16 is 0.01 μF, and DC1_PWDT_IN2 is the W-phase Hall sensor signal of the first motor, which is input to the first motor control chip U1 after being filtered by resistors and capacitors.

[0074] The resistor R46 is 560 ohms, the resistor R47 is 1K ohms, the capacitor C17 is 0.01 μF, and DC1_PWM1_CH1 is the encoder B-phase signal of the first motor, which is input to the first motor control chip U1 after being filtered by resistors and capacitors.

[0075] The resistor R52 is 560 ohms, the resistor R53 is 1K ohms, the capacitor C18 is 0.01 μF, and DC1_PWM1_CH0 is the encoder A phase signal of the first motor, which is input to the first motor control chip U1 after being filtered by resistors and capacitors.

[0076] DC2_H_U, DC2_H_V, DC2_H_W are the U, V, W phase Hall sensor signals of the second motor respectively, and DC2_E-PWM1, DC2_E-PWM0 are the AB phase signals of the second motor encoder respectively.

[0077] The resistor R104 is 560 ohms, the resistor R106 is 1K ohms, the capacitor C36 is 0.01 μF, and DC2_PWDT_IN0 is the U-phase Hall sensor signal of the second motor, which is input to the second motor control chip U12 after being filtered by resistors and capacitors.

[0078] The resistor R109 is 560 ohms, the resistor R110 is 1K ohms, the capacitor C42 is 0.01 μF, and DC2_PWDT_IN1 is the V-phase Hall sensor signal of the second motor, which is input to the second motor control chip U12 after being filtered by resistors and capacitors.

[0079] The resistor R115 is 560 ohms, the resistor R117 is 1K ohms, the capacitor C43 is 0.01 μF, and DC2_PWDT_IN2 is the W-phase Hall sensor signal of the second motor, which is input to the second motor control chip U12 after being filtered by resistors and capacitors.

[0080] The resistor R121 is 560 ohms, the resistor R122 is 1K ohms, the capacitor C44 is 0.01 μF, and DC2_PWM1_CH1 is the encoder B phase signal of the second motor, which is input to the second motor control chip U12 after being filtered by resistors and capacitors.

[0081] The resistor R127 is 560 ohms, the resistor R128 is 1K ohms, the capacitor C45 is 0.01 μF, and DC2_PWM1_CH0 is the encoder A phase signal of the second motor, which is input to the second motor control chip U12 after being filtered by resistors and capacitors.

[0082] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

[0083] The present invention can make the control circuit of the walker wheelchair run stably, adapt to various complex road conditions, and be stable when operated by the user.

Claims

1. A wheelchair drive control circuit, comprising a processor and its peripheral circuits, a current drive circuit, and a sampling circuit, characterized in that: The processor and its peripheral circuits include a main control chip, a first motor control chip and a second motor control chip; the current drive circuit includes a first current drive circuit and a sampling amplifier circuit thereof, a second current drive circuit and a sampling amplifier circuit thereof and a reference sampling circuit; the first motor control chip and the second motor control chip provide control signals for the drive chips of the first motor and the second motor respectively, and the communication method between the first motor control chip and the second motor control chip is serial communication; the main control chip is used to control the first motor control chip and the second motor control chip, and the communication method is serial communication; in the sampling amplifier circuit, the bias voltage of the same direction end of the operational amplifier is 2.5V.

2. The wheelchair drive control circuit according to claim 1, characterized in that: The sampling and amplifying circuit includes the MCP6022 chip.

3. The wheelchair drive control circuit according to claim 2, characterized in that: It includes a logic comparison sampling circuit for the motor current overcurrent signal.

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