Pressure detection circuit in motor operation process

Abstract

The utility model provides a pressure detection circuit in a motor operation process, comprising an MCU module and an H-bridge drive circuit composed of a PMOS tube and an NMOS tube, the NMOS tube is integrated in the MCU module, the MCU module comprises a control chip, an ADC acquisition filtering module and a timer module, the timer module generates a PWM signal to control the conduction and cut-off of the PMOS tube and the NMOS tube, and the control chip is connected with the control chip. A motor is connected between the two PMOS transistors and the two NMOS transistors, the grid electrodes of the two PMOS transistors are respectively connected with the timer module, the grid electrodes of the two NMOS transistors are respectively connected with the timer module, the source electrodes of the two NMOS transistors are respectively connected with the ADC acquisition filtering module to form an NMOS channel, the current of the motor is acquired through the NMOS channel, and the current of the motor is acquired through the ADC acquisition filtering module. And the collected motor current is converted into a current digital signal to be sent to the control chip. According to the utility model, the two external PMOS tubes and the two large-current NMOS tubes in the MCU chip are used to form an H-bridge driving circuit, and the pressure monitoring of the motor load is realized through PWM signal control and current detection.

Description

Technical Field

[0001] The utility model relates to the technical field of motor drive control, in particular to a pressure detection circuit in the running process of a motor. Background Art

[0002] At present, the way MCU controls motors in the industrial and consumer electronics fields does rely mainly on high-current MOS tubes, which control the operation of the motor by controlling the conduction and cutoff of the MOS tube. In order to more accurately control the operation of the motor, control the torque of the motor, and the stall change of the motor, pressure detection devices are usually required, such as strain sensors, pressure sensors, force-sensitive resistor sensors, etc. No matter which pressure detection device is used, it will increase the cost and structure of the product. For example, for products with sensitive spatial structures such as washing machines, air conditioners, and industrial robotic arms, adding sensors may make the product design more complicated or even unable to adapt to the existing product space. In the field of consumer electronics, such as electric shavers, electric toothbrushes and other products, the requirements for cost and structure are more stringent. The use of these sensors may increase the price of the product and reduce market competitiveness. Therefore, although these sensors play an important role in motor control, they usually increase the cost and structural complexity of the product.

[0003] At present, the circuit using H-bridge to drive the motor is a common circuit for MCU to control DC brushed motors and linear motors. There are two MOS tubes connected to the ground in the H-bridge circuit, and the current is usually obtained by dual-resistance sampling. This acquisition method requires 4 ADC channels, so the chip is required to provide 4 ADC channels, occupying 4 pins, and adding two additional resistors to the circuit. For consumer electronic products such as personal care, most of their functions are relatively simple, so they are sensitive to cost and volume. At this time, adding two additional resistors and requiring 4 pins with ADC functions to be allocated on the chip for current acquisition is unacceptable. If multiple high-current MOS tubes can be built into the chip, and the chip has a separate ADC channel for current sampling for the MOS tubes, then the motor current can be sampled without adding MOS tubes, resistors and ADC modules, which will greatly promote the development of low-cost and low-complexity motor-related products. Utility Model Content

[0004] In order to solve the problems existing in the prior art, the utility model provides a pressure detection circuit during the operation of a motor, which uses an MCU and a MOS tube to construct an H-bridge circuit to drive the motor, and realizes pressure monitoring of the motor load through PWM control and current detection.

[0005] The utility model achieves the above-mentioned purpose through the following technical solutions:

[0006] A pressure detection circuit during motor operation comprises an MCU module, an H-bridge drive circuit composed of two PMOS tubes and two NMOS tubes, the two NMOS tubes are integrated in the MCU module, the MCU module comprises a control chip, an ADC acquisition filter module and a timer module, the control chip is respectively connected to the ADC acquisition filter module and the timer module, the first PMOS tube, the second PMOS tube, the first NMOS tube and the second NMOS tube are respectively connected to the control chip, and a PWM signal is generated by the timer module to control the conduction and cutoff of the PMOS tube and the NMOS tube, a motor is connected between the two PMOS tubes and the two NMOS tubes, one end of the motor is connected between the source of the first PMOS tube and the drain of the first NMOS tube, and the other end of the motor is connected between the source of the second PMOS tube and the drain of the second NMOS tube;

[0007] Among them, the drains of the two PMOS tubes are respectively connected to the power supply Vdd signal, the gates of the two PMOS tubes are respectively connected to the timer module, the gates of the two NMOS tubes are respectively connected to the timer module, and the sources of the two NMOS tubes are respectively connected to the ADC acquisition filter module to form an NMOS channel. The ADC acquisition filter module collects the motor current through the NMOS channel, and converts the collected motor current into a current digital signal and sends it to the control chip.

[0008] A further solution is that the drain of the first PMOS tube is used to access the power supply Vdd signal, the drain of the second PMOS tube is used to access the power supply Vdd signal, the gate of the first PMOS tube is used to connect to the timer module, the gate of the second PMOS tube is used to connect to the timer module, the source of the first PMOS tube is connected to the drain of the first NMOS tube and then connected to one end of the motor, the source of the second PMOS tube is connected to the drain of the second NMOS tube and then connected to the other end of the motor, the source of the first NMOS tube is used to connect to the ADC acquisition filter module, the source of the second NMOS tube is used to connect to the ADC acquisition filter module, the gate of the first NMOS tube is used to connect to the timer module, and the gate of the second NMOS tube is used to connect to the timer module.

[0009] A further solution is that when the first PMOS tube and the second NMOS tube are both turned on, the NMOS channel of the ADC acquisition filter module is turned on to collect the motor current.

[0010] A further solution is that when the second PMOS tube and the first NMOS tube are both turned on, the NMOS channel of the ADC acquisition filter module is turned on to collect the motor current.

[0011] A further solution is that the ADC acquisition filter module includes an acquisition port, a filter protection circuit, and an ADC analog-to-digital converter. The acquisition port is used to acquire the motor current. The acquisition port is connected to the filter protection circuit, and the filter protection circuit is connected to the ADC analog-to-digital converter.

[0012] A further solution is that the filtering protection circuit includes a rectifier bridge, a ripple filter capacitor, a three-terminal EMI filter, and a low-pass RC filter capacitor. The input end of the rectifier bridge is connected to the acquisition port, one end of the ripple filter capacitor is connected between the output end of the rectifier bridge and the first end of the three-terminal EMI filter, the other end of the ripple filter capacitor is grounded, the second end of the three-terminal EMI filter is connected to the input end of the low-pass RC filter capacitor, the output end of the low-pass RC filter capacitor is connected to the ADC analog-to-digital converter, and the third end of the three-terminal EMI filter is grounded.

[0013] A further solution is that it also includes an alarm module, and the control chip is used to generate an alarm signal according to the received motor current and output the alarm signal to the alarm module.

[0014] A further solution is to further include a CANBUS communication interface circuit, which is connected to an external expansion device and is used to transmit the motor current data to the external expansion device.

[0015] A further solution is to further include a motor power supply module for supplying power to the motor in different environments.

[0016] It can be seen that compared with the prior art, the utility model integrates a high-current MOS tube into the MCU chip, and uses two external PMOS tubes and two high-current NMOS tubes of the MCU chip to form an H-bridge drive circuit, allowing the motor to switch between forward and reverse rotation. The timer module in the MCU is used to generate a PWM pulse width modulation signal to control the conduction and cutoff of the four MOS tubes, thereby controlling the operation of the motor. When a pair of PMOS and NMOS tubes (not directly connected) in the H-bridge circuit are turned on at the same time, the NMOS channel of the ADC is turned on to collect the motor current. The ADC module is responsible for converting the current signal into a digital signal for subsequent processing by the MCU;

[0017] Furthermore, when the motor is not subjected to external pressure, its current will remain at a relatively stable baseline value. However, when external forces (such as an object pressing on the motor) act on the motor, the motor needs a larger current to overcome this resistance. Therefore, when the MCU detects a sudden increase in the motor current, it can be determined that an object is pressing on the motor, thereby realizing pressure detection during the operation of the motor.

[0018] The utility model is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The utility model is a circuit principle diagram of a pressure detection circuit embodiment during the operation of a motor. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution of the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings of the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all of the embodiments. Based on the described embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0021] See also Figure 1 The pressure detection circuit involved in the operation process of a motor in this embodiment includes an MCU module 10, an H-bridge driving circuit composed of two PMOS tubes and two NMOS tubes, the two NMOS tubes are integrated in the MCU module 10, the MCU module 10 includes a control chip, an ADC acquisition filter module 11 and a timer module 12, the control chip is used for the overall control logic, the ADC acquisition filter module 11 is used to collect and process the motor current signal, and the timer module 12 is used to generate a PWM signal.

[0022] Among them, the control chip is connected to the ADC acquisition filter module 11 and the timer module 12 respectively, the first PMOS tube P1, the second PMOS tube P2, the first NMOS tube N1, and the second NMOS tube N2 are connected to the control chip respectively, and the PWM signal is generated by the timer module 12 to control the conduction and cutoff of the PMOS tube and the NMOS tube. A motor M is connected between the two PMOS tubes and the two NMOS tubes, one end of the motor M is connected between the source of the first PMOS tube P1 and the drain of the first NMOS tube N1, and the other end of the motor M is connected between the source of the second PMOS tube P2 and the drain of the second NMOS tube N2;

[0023] Among them, the drains of the two PMOS tubes are respectively connected to the power supply Vdd signal, the gates of the two PMOS tubes are respectively connected to the timer module 12, the gates of the two NMOS tubes are respectively connected to the timer module 12, and the sources of the two NMOS tubes are respectively connected to the ADC acquisition filter module 11 to form an NMOS channel. The ADC acquisition filter module 11 collects the motor current through the NMOS channel, and converts the collected motor current into a current digital signal and sends it to the control chip.

[0024] This embodiment provides an innovative pressure detection circuit during the operation of the motor M. The circuit combines an MCU module 10, an H-bridge drive circuit, and an ADC acquisition filter module 11 to achieve accurate monitoring of the motor current, thereby achieving pressure detection during the operation of the motor M.

[0025] Specifically, the drain of the first PMOS tube P1 is used to access the power supply Vdd signal, the drain of the second PMOS tube P2 is used to access the power supply Vdd signal, the gate of the first PMOS tube P1 is used to connect to the timer module 12, the gate of the second PMOS tube P2 is used to connect to the timer module 12, the source of the first PMOS tube P1 is connected to the drain of the first NMOS tube N1 and then connected to one end of the motor M, the source of the second PMOS tube P2 is connected to the drain of the second NMOS tube N2 and then connected to the other end of the motor M, the source of the first NMOS tube N1 is used to connect to the ADC acquisition filter module 11, the source of the second NMOS tube N2 is used to connect to the ADC acquisition filter module 11, the gate of the first NMOS tube N1 is used to connect to the timer module 12, and the gate of the second NMOS tube N2 is used to connect to the timer module 12.

[0026] In this embodiment, when the first PMOS transistor P1 and the second NMOS transistor N2 are both turned on, the NMOS channel of the ADC acquisition filter module 11 is turned on to collect the motor current.

[0027] In this embodiment, when the second PMOS transistor P2 and the first NMOS transistor N1 are both turned on, the NMOS channel of the ADC acquisition filter module 11 is turned on to collect the motor current.

[0028] In this embodiment, an H-bridge driving circuit is composed of two external PMOS tubes and two NMOS tubes inside the MCU, which is used to control the forward rotation, reverse rotation and stop of the motor M. The motor M is connected to the two ends of the H-bridge circuit, receives the control signal from the H-bridge circuit and drives the motor M to move.

[0029] In this embodiment, the ADC acquisition filter module 11 includes an acquisition port, a filter protection circuit, and an ADC analog-to-digital converter. The acquisition port is used to acquire the motor current. The acquisition port is connected to the filter protection circuit, and the filter protection circuit is connected to the ADC analog-to-digital converter. It can be seen that when a pair of PMOS and NMOS tubes (not directly connected) are turned on at the same time, the ADC acquisition filter module 11 acquires the motor current through the NMOS channel and converts it into a digital signal for the control chip to process.

[0030] In this embodiment, the filtering protection circuit includes a rectifier bridge, a ripple filter capacitor, a three-terminal EMI filter, and a low-pass RC filter capacitor. The input end of the rectifier bridge is connected to the acquisition port, one end of the ripple filter capacitor is connected between the output end of the rectifier bridge and the first end of the three-terminal EMI filter, the other end of the ripple filter capacitor is grounded, the second end of the three-terminal EMI filter is connected to the input end of the low-pass RC filter capacitor, the output end of the low-pass RC filter capacitor is connected to the ADC analog-to-digital converter, and the third end of the three-terminal EMI filter is grounded. It can be seen that these components together constitute an efficient filtering protection circuit, which can remove noise and interference in the current signal and improve the signal quality.

[0031] In this embodiment, an alarm module is also included, and the control chip is used to generate an alarm signal according to the received motor current and output the alarm signal to the alarm module. It can be seen that when the MCU detects that the motor current is abnormal (such as a sudden increase), it will output an alarm signal to the alarm module to remind the user or trigger other protection mechanisms.

[0032] In this embodiment, a CANBUS communication interface circuit is also included, and the CANBUS communication interface circuit is connected to an external expansion device and is used to transmit the motor current data to the external expansion device. It can be seen that the CANBUS communication interface circuit is used to transmit the motor current data to the external expansion device, which is convenient for users to perform remote monitoring and fault diagnosis.

[0033] In this embodiment, a motor M power supply module is also included, which is used to power the motor M in different environments. It can be seen that the motor M power supply module provides a stable power supply for the motor M, ensuring that the motor M can operate normally in different environments.

[0034] In actual applications, when the motor M operates normally, its current will remain at a relatively stable reference value. When an external force (such as an object pressing the motor M) acts on the motor M, the motor M needs a larger current to overcome this resistance, resulting in a sudden increase in current. The MCU monitors the motor current in real time through the ADC acquisition filter module 11. When an abnormal current is detected, it can be determined that an object is pressing the motor M, and a corresponding alarm or protection mechanism is triggered.

[0035] The utility model integrates a high-current MOS tube into the MCU chip, and uses two external PMOS tubes and two high-current NMOS tubes of the MCU chip to form an H-bridge drive circuit, allowing the motor M to switch between forward and reverse rotation. The timer module 12 in the MCU is used to generate a PWM pulse width modulation signal to control the conduction and cutoff of the four MOS tubes, thereby controlling the operation of the motor M. When a pair of PMOS and NMOS tubes (not directly connected) in the H-bridge circuit are turned on at the same time, the NMOS channel of the ADC is turned on to collect the motor current. The ADC module is responsible for converting the current signal into a digital signal for subsequent processing by the MCU; further, when the motor M is not subjected to external pressure, its current will remain at a relatively stable reference value. However, when an external force (such as an object pressing the motor M) acts on the motor M, the motor M needs a larger current to overcome this resistance. Therefore, when the MCU detects that the motor current suddenly increases, it can be judged that an object is pressing the motor M, thereby realizing pressure detection during the operation of the motor M.

[0036] Therefore, the pressure detection circuit provided in this embodiment has the following advantages:

[0037] 1. High integration: Integrating high-current MOS tubes into MCU chips reduces the number of external components and improves system reliability and stability.

[0038] 2. Accurate current monitoring: Through the ADC acquisition filter module 11 and the filter protection circuit, accurate monitoring and noise removal of the motor current can be achieved, thereby improving the signal quality.

[0039] 3. Pressure detection: The external pressure is sensed according to the change of motor current, which realizes the pressure detection during the operation of motor M and improves the intelligence level of the system.

[0040] 4. Flexible communication interface: Through the CANBUS communication interface circuit, the motor current data can be easily transmitted to external expansion devices to achieve remote monitoring and fault diagnosis.

[0041] Therefore, the pressure detection circuit during the operation of the motor M provided by the utility model has the advantages of high integration, accurate current monitoring, pressure detection and flexible communication interface, etc., which provides strong support for the safe operation and fault diagnosis of the motor M.

[0042] The above-mentioned implementation modes are only preferred implementation modes of the present invention, and cannot be used to limit the protection scope of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. A pressure detection circuit during motor operation, characterized in that: include: An MCU module, an H-bridge driving circuit composed of two PMOS tubes and two NMOS tubes, wherein the two NMOS tubes are integrated in the MCU module, the MCU module comprises a control chip, an ADC acquisition filter module and a timer module, the control chip is respectively connected to the ADC acquisition filter module and the timer module, the first PMOS tube, the second PMOS tube, the first NMOS tube and the second NMOS tube are respectively connected to the control chip, and a PWM signal is generated by the timer module to control the conduction and cutoff of the PMOS tube and the NMOS tube, a motor is connected between the two PMOS tubes and the two NMOS tubes, one end of the motor is connected between the source of the first PMOS tube and the drain of the first NMOS tube, and the other end of the motor is connected between the source of the second PMOS tube and the drain of the second NMOS tube; Among them, the drains of the two PMOS tubes are respectively connected to the power supply Vdd signal, the gates of the two PMOS tubes are respectively connected to the timer module, the gates of the two NMOS tubes are respectively connected to the timer module, and the sources of the two NMOS tubes are respectively connected to the ADC acquisition filter module to form an NMOS channel. The ADC acquisition filter module collects the motor current through the NMOS channel, and converts the collected motor current into a current digital signal and sends it to the control chip.

2. The pressure detection circuit according to claim 1, characterized in that: The drain of the first PMOS tube is used to access the power supply Vdd signal, the drain of the second PMOS tube is used to access the power supply Vdd signal, the gate of the first PMOS tube is used to connect to the timer module, the gate of the second PMOS tube is used to connect to the timer module, the source of the first PMOS tube is connected to the drain of the first NMOS tube and then connected to one end of the motor, the source of the second PMOS tube is connected to the drain of the second NMOS tube and then connected to the other end of the motor, the source of the first NMOS tube is used to connect to the ADC acquisition filter module, the source of the second NMOS tube is used to connect to the ADC acquisition filter module, the gate of the first NMOS tube is used to connect to the timer module, and the gate of the second NMOS tube is used to connect to the timer module.

3. The pressure detection circuit according to claim 1, characterized in that: When the first PMOS tube and the second NMOS tube are both turned on, the NMOS channel of the ADC acquisition filter module is turned on to collect the motor current.

4. The pressure detection circuit according to claim 1, characterized in that: When the second PMOS tube and the first NMOS tube are both turned on, the NMOS channel of the ADC acquisition filter module is turned on to collect the motor current.

5. The pressure detection circuit according to claim 1, characterized in that: The ADC acquisition filter module includes an acquisition port, a filter protection circuit, and an ADC analog-to-digital converter. The acquisition port is used to acquire motor current. The acquisition port is connected to the filter protection circuit, and the filter protection circuit is connected to the ADC analog-to-digital converter.

6. The pressure detection circuit according to claim 5, characterized in that: The filtering protection circuit includes a rectifier bridge, a ripple filter capacitor, a three-terminal EMI filter, and a low-pass RC filter capacitor. The input end of the rectifier bridge is connected to the acquisition port, one end of the ripple filter capacitor is connected between the output end of the rectifier bridge and the first end of the three-terminal EMI filter, the other end of the ripple filter capacitor is grounded, the second end of the three-terminal EMI filter is connected to the input end of the low-pass RC filter capacitor, the output end of the low-pass RC filter capacitor is connected to the ADC analog-to-digital converter, and the third end of the three-terminal EMI filter is grounded.

7. The pressure detection circuit according to any one of claims 1 to 6, characterized in that: It also includes an alarm module, and the control chip is used to generate an alarm signal according to the received motor current and output the alarm signal to the alarm module.

8. The pressure detection circuit according to any one of claims 1 to 6, characterized in that: It also includes a CANBUS communication interface circuit, which is connected to an external expansion device and is used to transmit the motor current data to the external expansion device.

9. The pressure detection circuit according to any one of claims 1 to 6, characterized in that: It also includes a motor power supply module, which is used to supply power to the motor under different environments.

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