Car window motor current ripple acquisition circuit based on hysteresis comparator

Abstract

The utility model provides a car window motor current ripple acquisition circuit based on a hysteresis comparator, comprising a relay connected with a car window motor, the on-off of the relay being controlled by a relay control circuit; the first end of the sampling resistor is connected with the relay; the ripple wave processing circuit is connected with the first end of the sampling resistor, and the ripple wave processing circuit is used for carrying out ripple wave processing on ripple wave signals collected at the two ends of the sampling resistor to generate square wave signals; the single chip microcomputer is connected with the relay and the ripple wave acquisition circuit; the single-chip microcomputer is used for receiving the square wave signal processed by the ripple processing circuit. According to the utility model, the motion position of the car window can be monitored, the functions of automatic lifting, anti-pinch and the like of the car window are realized, and the problem of poor ripple wave acquisition effect in the prior art is solved.

Description

Technical Field

[0001] This utility model relates to the field of automotive circuit technology, and in particular to a window motor current ripple acquisition circuit based on a hysteresis comparator. Background Technology

[0002] As customer demands for automotive services increase, many car models have added automatic window operation. Ripple acquisition circuits can use hardware and software to make the output ripple count closer to the actual ripple count generated by the motor. Software ripple detection can then monitor the window position and status, enabling various window movement functions.

[0003] However, traditional ripple acquisition circuits place high demands on the window motor, requiring a window motor whose generated ripple waveform is close to a sine wave. If the ripple waveform of the window motor itself is poor, it may cause the software to recognize the window position inaccurately, resulting in functional problems, making it difficult to control the automatic raising and lowering of the window, and even causing accidental pinching.

[0004] There is currently no effective solution to the problem of poor ripple acquisition in existing related technologies. Utility Model Content

[0005] This invention provides a ripple acquisition circuit for a car window motor current based on a hysteresis comparator, which solves the defect of poor ripple acquisition effect in the prior art.

[0006] This utility model provides a vehicle window motor current ripple acquisition circuit based on a hysteresis comparator, comprising:

[0007] A relay, which is connected to the window motor, and the on / off state of the relay is controlled by a relay control circuit;

[0008] A sampling resistor, the first end of which is connected to the relay;

[0009] A ripple processing circuit is connected to the first end of the sampling resistor. The ripple processing circuit is used to process the ripple signal collected from both ends of the sampling resistor to generate a square wave signal.

[0010] A microcontroller is connected to the relay and the ripple acquisition circuit; the microcontroller is used to receive the square wave signal processed by the ripple processing circuit and monitor the movement position of the window controlled by the window motor.

[0011] According to the present invention, a window motor current ripple acquisition circuit based on a hysteresis comparator is provided, wherein the ripple processing circuit includes a differential amplifier unit, a filter unit and a hysteresis comparator unit connected in sequence.

[0012] The differential amplifier unit is used to differentially amplify the ripple signal acquired from both ends of the sampling resistor;

[0013] The filtering unit is used to filter the ripple signal after differential amplification.

[0014] The hysteresis comparison unit is used to perform hysteresis comparison on the filtered ripple signal and convert the ripple signal into a square wave signal.

[0015] According to the present invention, a window motor current ripple acquisition circuit based on a hysteresis comparator is provided. The differential amplifier unit includes a first operational amplifier, the positive input terminal of which is connected to resistors R31 and R36, and resistor R31 is grounded; the inverting input terminal of the first operational amplifier is connected to resistor R45, and resistor R45 is grounded; the differential amplifier unit further includes resistor R46, the first end of which is connected to the output terminal of the first operational amplifier, and the second end of which is connected to the inverting input terminal of the first operational amplifier.

[0016] According to the present invention, a window motor current ripple acquisition circuit based on a hysteresis comparator is provided. The filtering unit includes a resistor R74. The first end of the resistor R74 is connected to the output terminal of the first operational amplifier. The second end of the resistor R74 is connected to a capacitor C22 and a resistor R40 in sequence. The first end of the capacitor C22 is connected to the resistor R74. The first end of the capacitor C22 is also connected to a capacitor C28. The second end of the capacitor C22 is connected to a resistor R34. The second end of the capacitor C22 is also connected to a resistor R42.

[0017] According to the present invention, a window motor current ripple acquisition circuit based on a hysteresis comparator is provided. The hysteresis comparator unit includes a second operational amplifier, the positive input terminal of which is connected to the resistor R40, and the output terminal of which is connected to the resistor R32. The hysteresis comparator unit also includes a resistor R44, the first end of which is connected to the positive input terminal of the second operational amplifier, and the second end of which is connected to the output terminal of the second operational amplifier.

[0018] According to the present invention, a window motor current ripple acquisition circuit based on a hysteresis comparator is provided. The relay control circuit includes a resistor R78, an inductor RS4, and a resistor R79 connected to pin 2 of the relay. A capacitor C40 is connected to the end of the resistor R79 away from the relay, and the capacitor C40 is grounded. A capacitor C30 is connected to the end of the resistor R78 away from the relay, and the capacitor C30 is grounded.

[0019] According to the present invention, a window motor current ripple acquisition circuit based on a hysteresis comparator is provided. The acquisition circuit further includes a low dropout voltage regulator, the first terminal of which is connected to the microcontroller.

[0020] According to the present invention, a window motor current ripple acquisition circuit based on a hysteresis comparator is provided, wherein the second stage of the low-dropout regulator and the relay are both connected to a power supply, and the power supply is controlled by a power control circuit.

[0021] According to the present invention, a hysteresis comparator-based current ripple acquisition circuit for a car window motor is provided. The power control circuit includes resistors R3, R50, and R51 connected in series. A capacitor C19 is provided between resistors R3 and R50, and a capacitor C20 is provided between resistors R50 and R51. Both capacitors C19 and C20 are grounded, and resistor R51 is grounded.

[0022] According to the present invention, a window motor current ripple acquisition circuit based on a hysteresis comparator is provided, wherein the microcontroller and the sampling resistor are grounded.

[0023] The ripple acquisition circuit for the car window motor current based on a hysteresis comparator provided by this utility model mainly detects the voltage across the sampling resistor. After the acquisition circuit detects the ripple signal, it is converted into a square wave signal after differential amplification, filtering and comparison by the ripple processing circuit. The microcontroller acquires the number of rising and falling edges of the square wave signal, thereby monitoring the movement position of the car window and realizing functions such as automatic window raising and lowering and anti-pinch. This solves the problem of poor ripple acquisition effect in existing related technologies. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the window motor current ripple acquisition circuit based on a hysteresis comparator proposed in this utility model;

[0026] Figure 2 This is a circuit diagram of the ripple processing circuit in this utility model;

[0027] Figure 3 This is a circuit diagram of the relay control circuit in this utility model;

[0028] Figure 4 This is a circuit diagram of the power control circuit in this utility model. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0030] A circuit for acquiring current ripple of a car window motor based on a hysteresis comparator. Figure 1 This is a schematic diagram of the window motor current ripple acquisition circuit based on a hysteresis comparator proposed in this utility model, as shown below. Figure 1 As shown, the acquisition circuit includes:

[0031] The relay is connected to the window motor, and the on / off state of the relay is controlled by the relay control circuit.

[0032] The sampling resistor has its first terminal connected to the relay.

[0033] The ripple processing circuit is connected to the first end of the sampling resistor. The ripple processing circuit is used to process the ripple signal collected from both ends of the sampling resistor to generate a square wave signal.

[0034] The microcontroller is connected to the relay and the ripple acquisition circuit. The microcontroller receives the square wave signal processed by the ripple processing circuit and monitors the movement position of the window controlled by the window motor. The microcontroller and the sampling resistor are grounded.

[0035] In this invention, the circuit structure provides power through a plug-in and enables communication with external signals. In this circuit structure, the window motor is controlled by a relay to output DC power in both forward and reverse directions. The forward and reverse outputs control the window motor to rotate in either direction. When the window motor rotates, the phase change of the rotor in the magnetic field affects the change in its coil current, thus generating ripple. Ripple detection is mainly achieved by detecting the voltage across the sampling resistor. After the acquisition circuit detects the ripple signal, it is differentially amplified, filtered, and compared by the ripple processing circuit, converting it into a square wave signal. The microcontroller acquires the number of rising and falling edges of the square wave signal, thereby monitoring the window's movement position and enabling automatic window raising and lowering, anti-pinch, and other functions. This solves the problem of poor ripple acquisition in existing related technologies.

[0036] In some of these embodiments, Figure 2This is a circuit diagram of the ripple processing circuit in this utility model, as shown below. Figure 2 As shown, the ripple processing circuit includes a differential amplifier unit, a filter unit, and a hysteresis comparator unit connected in sequence. The differential amplifier unit is used to differentially amplify the ripple signal acquired from both ends of the sampling resistor. The filter unit is used to filter the ripple signal after differential amplification. The hysteresis comparator unit is used to perform hysteresis comparison on the filtered ripple signal to convert the ripple signal into a square wave signal.

[0037] Specifically, the differential amplifier unit includes a first operational amplifier, with resistors R31 and R36 connected to the non-inverting input terminal of the operational amplifier, and resistor R31 grounded; a resistor R45 is connected to the inverting input terminal of the first operational amplifier, and resistor R45 is grounded; the differential amplifier unit also includes a resistor R46, with the first end of resistor R46 connected to the output terminal of the first operational amplifier, and the second end of resistor R46 connected to the inverting input terminal of the first operational amplifier.

[0038] The filter unit includes a resistor R74. The first end of the resistor R74 is connected to the output of the first operational amplifier. The second end of the resistor R74 is connected to a capacitor C22 and a resistor R40 in sequence. The first end of the capacitor C22 is connected to the resistor R74. The first end of the capacitor C22 is also connected to a capacitor C28. The second end of the capacitor C22 is connected to a resistor R34. The second end of the capacitor C22 is also connected to a resistor R42.

[0039] The hysteresis comparator includes a second operational amplifier, the positive input of which is connected to resistor R40, and the output of which is connected to resistor R32; the hysteresis comparator also includes resistor R44, the first end of which is connected to the positive input of the second operational amplifier, and the second end of which is connected to the output of the second operational amplifier.

[0040] In this embodiment, the first operational amplifier, the hysteresis comparator unit, and the second operational amplifier are integrated into a single chip. Together with their peripheral circuitry, they achieve differential amplification and comparison of the input signal, avoiding environmental interference. The ripple signal acquired from the sampling resistor is differentially amplified at both ends of the first operational amplifier and then output to the filtering unit. After the filtering unit filters out high frequencies and blocks DC current, the signal is output to the hysteresis comparator unit.

[0041] Specifically, after differential amplification by the first operational amplifier, the filtered ripple signal is input to the hysteresis comparator. According to the hysteresis effect of the hysteresis comparator, when the input signal is greater than the high reference voltage V1, the output of the hysteresis comparator is higher, and when the input signal is less than the low reference voltage V2, the output of the hysteresis comparator is lower. Therefore, it can filter out the noise between voltages V1 and V2, thereby detecting ripple changes in real time.

[0042] In some of these embodiments, such as Figure 3 As shown, Figure 3 This is a circuit diagram of the relay control circuit in this utility model. The relay control circuit includes a resistor R78, an inductor RS4, and a resistor R79 connected to pin 2 of the relay. A capacitor C40 is connected to the end of resistor R79 away from the relay, and capacitor C40 is grounded. A capacitor C30 is connected to the end of resistor R78 away from the relay, and capacitor C30 is grounded.

[0043] In some embodiments, the acquisition circuit further includes a low-dropout regulator, the first terminal of which is connected to the microcontroller. Further, the second terminal of the low-dropout regulator and the relay are both connected to a +5V power supply, which is controlled by a power control circuit. Figure 4 As shown, Figure 4 This is a circuit diagram of the power control circuit in this utility model. The power control circuit includes resistors R3, R50 and R51 connected in series. A capacitor C19 is provided between resistors R3 and R50, and a capacitor C20 is provided between resistors R50 and R51. Both capacitors C19 and C20 are grounded, and resistor R51 is grounded.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A hysteresis comparator based window motor current ripple acquisition circuit, characterized by, The application relates to a window control system. The system comprises a relay connected with a window motor, the on-off of the relay is controlled by a relay control circuit; a sampling resistor, the first end of the sampling resistor is connected with the relay; a ripple processing circuit, the first end of the sampling resistor is connected with the ripple processing circuit, the ripple processing circuit is used for processing the ripple signal collected from the two ends of the sampling resistor to generate a square wave signal; a single-chip microcomputer, the single-chip microcomputer is connected with the relay and the ripple collection circuit; the single-chip microcomputer is used for receiving the square wave signal processed by the ripple processing circuit and monitoring the moving position of the window controlled by the window motor.

2. The hysteresis comparator based window motor current ripple harvesting circuit of claim 1, wherein, The ripple processing circuit comprises a differential amplification unit, a filter unit and a hysteresis comparison unit connected in sequence; the differential amplification unit is used for differentially amplifying the ripple signal collected from the two ends of the sampling resistor; the filter unit is used for filtering the ripple signal after the differential amplification; the hysteresis comparison unit is used for hysteresis comparing the ripple signal after the filtering to convert the ripple signal into a square wave signal.

3. The hysteresis comparator based window motor current ripple harvesting circuit of claim 2, wherein, The differential amplification unit comprises a first operational amplifier, the positive input end of the operational amplifier is connected with a resistor R31 and a resistor R36, the resistor R31 is grounded; the inverting input end of the first operational amplifier is connected with a resistor R45, the resistor R45 is grounded; the differential amplification unit further comprises a resistor R46, the first end of the resistor R46 is connected with the output end of the first operational amplifier, and the second end of the resistor R46 is connected with the inverting input end of the first operational amplifier.

4. The hysteresis comparator based window motor current ripple harvesting circuit of claim 3, wherein, The filter unit comprises a resistor R74, the first end of the resistor R74 is connected with the output end of the first operational amplifier, and the second end of the resistor R74 is connected with a capacitor C22 and a resistor R40 in sequence; the first end of the capacitor C22 is connected with the resistor R74, the first end of the capacitor C22 is further connected with a capacitor C28, the second end of the capacitor C22 is connected with a resistor R34, and the second end of the capacitor C22 is further connected with a resistor R42.

5. The hysteresis comparator based window motor current ripple harvesting circuit of claim 4, wherein, The hysteresis comparison unit comprises a second operational amplifier, the positive input end of the second operational amplifier is connected with the resistor R40, and the output end of the second operational amplifier is connected with a resistor R32; the hysteresis comparison unit further comprises a resistor R44, the first end of the resistor R44 is connected with the positive input end of the second operational amplifier, and the second end of the resistor R44 is connected with the output end of the second operational amplifier.

6. The hysteresis comparator-based window motor current ripple harvesting circuit of claim 1, wherein, The relay control circuit comprises a resistor R78, an inductor RS4 and a resistor R79 connected with the No.2 pin of the relay, the resistor R79 is connected with a capacitor C40 away from the relay, and the capacitor C40 is grounded; the resistor R78 is connected with a capacitor C30 away from the relay, and the capacitor C30 is grounded.

7. The hysteresis comparator-based window motor current ripple harvesting circuit of claim 1, wherein, The collection circuit further comprises a low-dropout regulator, the first end of the low-dropout regulator is connected with the single-chip microcomputer.

8. The hysteresis comparator-based window motor current ripple harvesting circuit of claim 7, wherein, The second section of the low dropout regulator and the relay are connected with a power supply, and the power supply is controlled by a power supply control circuit.

9. The hysteresis comparator-based window motor current ripple harvesting circuit of claim 8, wherein, The power supply control circuit comprises resistors R3, R50 and R51 connected in series, a capacitor C19 arranged between the resistor R3 and the resistor R50, and a capacitor C20 arranged between the resistor R50 and the resistor R51; the capacitor C19 and the capacitor C20 are grounded, and the resistor R51 is grounded.

10. The hysteresis comparator-based window motor current ripple harvesting circuit of claim 1, wherein, The single-chip microcomputer and the sampling resistor are grounded.

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