A Brushless Wiper Motor Control Method, System and Device Based on Sine and Cosine Position Signals

Abstract

The present invention discloses a control method, system and device for a brushless wiper motor based on sine-cosine position signals, including the following steps: obtaining the sine-cosine position signals of an angle sensor disposed at the rotor of the brushless wiper motor; performing arctangent calculation on the sine-cosine position signals to obtain the real-time angle; calculating an estimated angle by collecting and calculating the back electromotive force signal of the brushless wiper motor, and calculating an angle error value based on the real-time angle and the estimated angle; calculating the current angle value according to the real-time angle and the angle compensation amount; The present invention obtains the sine-cosine position signals of the angle sensor at the rotor of the brushless wiper motor, combines the back electromotive force signal of the brushless wiper motor to calculate the estimated angle, and finally obtains the accurate current angle value through complex compensation and correction processes. This multi-signal fusion method effectively improves the accuracy of motor angle measurement and can more accurately reflect the actual position of the rotor of the brushless wiper motor.

Description

Technical Field

[0001] The present invention belongs to the field of vehicle signal processing, and particularly relates to a brushless wiper motor control method, system and device based on sine-cosine position signals. Background Art

[0002] The brushless wiper motor is a new motor technology widely used in the automotive field in recent years. Most traditional wiper motors use brushed DC motors, and they generally have the following problems: Wear and short lifespan: There is mechanical friction between the brushes and the commutator of the brushed motor, resulting in relatively fast wear of the brushes and the need for regular replacement, which increases the maintenance cost. Noise problem: The friction between the brushes and the commutator will generate obvious noise, affecting driving comfort. Unstable rotation speed: The rotation speed control accuracy of traditional motors is relatively low, and it is difficult to achieve precise speed adjustment. High energy consumption: The efficiency of brushed motors is relatively low, resulting in large energy consumption. The brushless wiper motor has improved many of the above-mentioned disadvantages compared with the brushed DC motor.

[0003] However, the measurement accuracy of the rotation amount of the brushless wiper motor directly affects its control performance and application effect. High-precision measurement of the rotation amount can achieve effects such as precise position control, stable rotation speed control, and optimized dynamic performance. The existing measurement of the rotation amount of the brushless wiper motor mainly sets Hall sensors on the motor stator to detect the position of the rotor magnetic poles. When the rotor rotates, the Hall sensors output pulse signals. By counting the number of pulses and calculating the pulse frequency, the rotation speed and position information of the motor can be obtained. However, this method has the accuracy limited by the resolution of the Hall sensors. And there will inevitably be energy loss when the motor transmits power from the driving end to the output end. In the existing technology, only the rotation of the motor is measured, and the actual rotation amount at the output end is lower than the detected value, and this error will directly affect the rotation measurement value of the brushless wiper motor, thereby affecting the high-precision control of the brushless wiper motor. Therefore, it is urgent to design a brushless wiper motor control method, system and device based on sine-cosine position signals. Summary of the Invention

[0004] The technical objective of the present invention is to provide a brushless wiper motor control method, system and device based on sine-cosine position signals to measure the rotation amount of the brushless wiper motor.

[0005] To solve the above problems, the technical solution of the present invention is as follows:

[0006] A brushless wiper motor control method based on sine-cosine position signals, which is applied to the real-time detection of the rotor position in a brushless wiper motor, includes the following steps:

[0007] Obtain the sine-cosine position signals corresponding to the angular position of the motor rotor at any moment;

[0008] Perform the arctangent calculation on the sine and cosine position signals to obtain the real-time angle of the motor;

[0009] Collect the back electromotive force signal of the brushless wiper motor and calculate to obtain the estimated angle. Compare the real-time angle and the estimated angle, and calculate the angle error value;

[0010] Calculate the optimized and updated angle value according to the real-time angle and the angle compensation amount;

[0011] Among them, the calculation of the angle compensation amount is as follows:

[0012] Based on the real-time angle, look up the table to obtain the sector number where the current rotor is located, and judge whether the sector sequence changes;

[0013] If it changes, read the current angle base value corresponding to the current sector, and determine the previous angle base value corresponding to the previous sector. Calculate the cumulative angle according to the previous angle base value and the estimated angle, obtain the error value between the cumulative angle and the real-time angle, and according to whether the error value exceeds the error threshold. If it exceeds the error threshold, it is determined that the estimated angle is abnormal, and the angle compensation amount is cleared; if it does not exceed the error threshold, the angle compensation amount is calculated by weighted calculation according to the real-time angle and the estimated angle;

[0014] If it does not change, judge whether the estimated angle satisfies being greater than or equal to the estimated threshold; if it does not satisfy, jump back to the step of obtaining the sine and cosine position signals; if it satisfies, update the real-time angle to the estimated angle, and calculate the angle compensation amount according to the angle error value and the estimated angle.

[0015] Further preferably, the obtained sine and cosine position signals are also subjected to low-pass filtering and normalization processing before the arctangent calculation. The calculation formula of the arctangent calculation is;

[0016]

[0017] Among them, is the sine signal, is the cosine signal.

[0018] Among them, by collecting the back electromotive force signal at the stator of the brushless wiper motor, calculate the time for the stator of the brushless wiper motor to rotate an electrical cycle of 360°, calculate the time for an average rotation of 60°, calculate the angular velocity of the rotor based on the time for an average rotation of 60°, and calculate the estimated angle through the angular velocity of the rotor;

[0019] The calculation method of the angle error value is the estimated angle minus the real-time angle.

[0020] Specifically, the sector where the rotor rotates is divided into six sectors, with each sector spaced 60°. The relationship between each sector and the angle is pre-marked, and the sector number where the rotor is located at the real-time angle is obtained by looking up the table according to the angle.

[0021] Among them, after it is determined that the sector has changed, the cumulative angle is calculated by adding the previous angle base value and the estimated angle, the error value is calculated by subtracting the real-time angle from the cumulative angle, and it is determined whether the error value exceeds the error threshold. Among them, the error threshold is set to 30°;

[0022] If it exceeds the error threshold, it is determined that the brushless wiper motor fluctuates, the estimated angle is abnormal data, the angle compensation amount is cleared, and the current angle value is equal to the real-time angle;

[0023] If it does not exceed the error threshold, the angle compensation amount is calculated by performing weighted calculation on the real-time angle and the estimated angle, and the current angle value is obtained by adding the real-time angle and the angle compensation amount.

[0024] Specifically, after it is determined that the sector has not changed, it is further determined whether the estimated angle satisfies being greater than or equal to the estimation threshold; among them, the selection range of the estimation threshold is 60 to 180°;

[0025] If it does not meet the requirement, it jumps back to the step of obtaining the sine and cosine position signals;

[0026] If it meets the requirement, the real-time angle is forcibly updated, the estimated angle is recognized as the rotor position, and the angle compensation amount is calculated. The angle compensation amount is calculated by multiplying the result of subtracting the angle error value from the estimated angle by the gain coefficient.

[0027] A brushless wiper motor control system based on sine and cosine position signals, which is adapted to the above-mentioned brushless wiper motor control method based on sine and cosine position signals, includes:

[0028] An interface module, a main control module, a drive circuit, a detection module, and a brushless wiper motor;

[0029] The interface module is electrically connected to the main control module. The interface module includes a power supply interface, a communication interface, and an angle detection interface, which provides power support to the main control module, the drive circuit, and the brushless wiper motor through the power supply interface, conveys control instructions to the main control module through the communication interface, and conveys angle detection signals to the main control module through the angle detection interface; among them, the angle detection signals include the sine and cosine position signals of the angle sensor at the rotor of the brushless wiper motor, and the analog signal of the angle sensor at the gear of the brushless wiper motor;

[0030] The main control module is also electrically connected to the drive circuit, and is configured to issue a control signal to the drive circuit according to the control instruction, and receive the angle detection signal to detect the rotation angles of the rotor and the gear of the brushless wiper motor in real time;

[0031] The drive circuit is electrically connected to the brushless wiper motor and is configured to receive a control signal to drive the brushless wiper motor to rotate;

[0032] The detection module is electrically connected to the main control module and the drive circuit respectively, and is configured to detect and transmit the motor current detection signal and the motor temperature detection signal to the main control module.

[0033] Specifically, the main control module includes a power supply module, a boost unit, a clock unit, a PWM generator, a wake-up unit, a communication unit, a storage unit, a microcontroller, a transceiver, an analog-to-digital converter, and a drive protection unit;

[0034] The power supply module is electrically connected to the power supply interface and is configured to provide power management for the main control module;

[0035] The boost unit is configured to provide a high voltage to the gate of the high-side MOS transistor of the H bridge of the drive circuit;

[0036] The clock unit is configured to provide a clock signal to the main control module;

[0037] The PWM generator is configured to generate a PWM signal and input it to the drive circuit;

[0038] The wake-up unit is configured to wake up the microcontroller from the low-power mode to the normal operating mode;

[0039] The transceiver is configured to receive control instructions;

[0040] The communication unit is configured to perform signal processing on the received control instructions and transmit them to the microcontroller;

[0041] The storage unit is configured to store relevant instructions for the microcontroller to run;

[0042] The microcontroller is configured to control the PWM generator according to the control instructions, the motor current detection signal, the motor temperature detection signal, and the angle detection signal to adjust the operation of the brushless wiper motor;

[0043] The analog-to-digital converter is configured to convert the motor current detection signal, the motor temperature detection signal, and the angle detection signal into digital signals recognizable by the microcontroller;

[0044] The drive protection unit is configured to achieve overcurrent protection by turning off the MOS transistors in the drive circuit.

[0045] A brushless wiper motor control device based on a sine-cosine position signal is adapted to the brushless wiper motor control method based on a sine-cosine position signal as described above;

[0046] The brushless wiper motor includes: a housing, a driving mechanism, and an output mechanism. The driving mechanism and the output mechanism are arranged inside the housing. A transmission rod is arranged inside the driving mechanism. One end of the transmission rod extends into the driving mechanism and realizes transmission connection, and the other end of the transmission rod is in transmission connection with the output mechanism.

[0047] A measurement component connected to the transmission rod is further provided. The measurement component includes a magnetic ring and a Hall sensor. The magnetic ring is sleeved on the transmission rod and is arranged close to the driving mechanism side. The Hall sensor is arranged close to the magnetic ring. The Hall sensor and the magnetic ring cooperate with each other and are configured to measure the rotation angle of the transmission rod in real time to generate sine and cosine position signals for measuring the rotation of the rotor of the brushless wiper motor.

[0048] An output rod, a rotating gear, and an angle sensor are arranged inside the output mechanism. The rotating gear is in transmission connection with the transmission rod, and the rotating gear is sleeved on the output rod. The angle sensor is configured to measure the rotation angle of the rotating gear in real time.

[0049] Further preferably, the driving mechanism further includes a stator, a rotor, an iron core, and a magnet.

[0050] The iron core is connected to the transmission rod.

[0051] A first circular through hole is opened in the center of the rotor, and the iron core is arranged inside the first circular through hole.

[0052] The magnet surrounds and fits on the side surface of the rotor.

[0053] The stator surrounds and fits on the inner wall of the housing and is arranged corresponding to the magnet.

[0054] Specifically, an installation frame is arranged inside the housing and on the path of the transmission rod. The installation frame is fixed inside the housing and is configured to install the Hall sensing circuit board. The Hall sensor is installed on the Hall sensing circuit board, and an inwardly concave notch is opened at the top of the Hall sensing circuit board. The transmission rod passes through the notch and is in transmission connection with the output mechanism. The magnetic ring is sleeved on the transmission rod, located between the Hall sensing circuit board and the iron core, and is arranged close to the Hall sensing circuit board.

[0055] Due to the adoption of the above technical solutions, the present invention has the following advantages and positive effects compared with the prior art:

[0056] The present invention obtains the sine and cosine position signals of the angle sensor at the rotor of the brushless wiper motor, combines with the back electromotive force signal of the brushless wiper motor to perform estimated angle calculation, and finally obtains an accurate current angle value through a complex compensation and correction process. This multi-signal fusion method effectively improves the accuracy of motor angle measurement and can more accurately reflect the actual position of the rotor of the brushless wiper motor.

[0057] The present invention not only provides a rotation measurement method, but also designs a complete rotation measurement system and device, covering multiple key parts such as an interface module, a main control module, a drive circuit, a detection module, etc., realizing the integrated integration from signal acquisition, processing to motor drive control, which is convenient for installation and deployment in practical applications. Brief Description of the Drawings

[0058] By reading the following detailed description of the preferred embodiments, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present invention.

[0059] Figure 1 It is a schematic flow chart of a brushless wiper motor control method based on sine and cosine position signals of the present invention;

[0060] Figure 2 It is a block diagram of the structure of a brushless wiper motor control system based on sine and cosine position signals of the present invention;

[0061] Figure 3 It is a schematic structural diagram of a brushless wiper motor control device based on sine and cosine position signals of the present invention.

[0062] Description of the Reference Numerals in the Drawings

[0063] 1: Hall sensor; 2: Magnetic ring; 3: Mounting bracket; 4: Stator; 5: Rotor; 6: Magnet; 7: Transmission rod; 8: Output rod; 9: Rotating gear. Detailed Embodiments

[0064] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the specific embodiments of the present invention will be described below with reference to the drawings. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings and other embodiments can be obtained.

[0065] To make the drawings concise, only the parts related to the present invention are schematically shown in each drawing, and they do not represent the actual structure of the product. In addition, to make the drawings concise and easy to understand, in some drawings, components with the same structure or function are only schematically shown one of them, or only one of them is marked. In this article, "one" not only means "only this one", but also means "more than one" situation.

[0066] The following further elaborates on a brushless wiper motor control method, system, and device based on sine-cosine position signals in conjunction with the accompanying drawings and specific embodiments. According to the following description and claims, the advantages and features of the present invention will become clearer.

[0067] Embodiment 1

[0068] Refer to Figure 1 , this embodiment provides a brushless wiper motor control method based on sine-cosine position signals, including the following steps:

[0069] First, obtain the signals of the angle sensor disposed at the rotor of the brushless wiper motor. In this embodiment, the angle sensor uses a Hall sensor, and a magnetic ring corresponding to the Hall sensor is disposed near the brushless wiper motor. The motor cooperates with the magnetic ring, and when the motor rotates, the magnetic field changes. The changing magnetic field is detected in real time by the Hall sensor, and then the signals of the Hall sensor are collected in real time, and two signals can be obtained, namely a sine signal and a cosine signal.

[0070] After sampling, low-pass filtering, normalization and other preprocessing are performed on the obtained sine-cosine position signals. After the preprocessing is completed, arctangent calculation is performed to obtain the real-time angle. The calculation formula for arctangent calculation is:

[0071]

[0072] Among them, is the sine signal, is the cosine signal.

[0073] Then, calculate the angular velocity, estimated angle, and angle error value respectively.

[0074] Specifically, the back electromotive force signal of the brushless wiper motor is obtained by hardware sampling of the floating phase line voltage. The time for the stator of the brushless wiper motor to rotate an electrical cycle of 360° is used to calculate the time for an average rotation of 60°, so as to achieve the filtering effect. Then, the angular velocity of the rotor is calculated based on the time for an average rotation of 60°, and the estimated angle is obtained by integral calculation of the angular velocity of the rotor. The calculation formula is;

[0075] Among them, represents the estimated angle, represents the angular velocity, represents the time.

[0076] The calculation method of the angle error value is the estimated angle minus the real-time angle.

[0077] Then, the current angle value is calculated based on the real-time angle and the angle compensation amount, and this current angle value is the final value to be solved in this embodiment. Now, the calculation of the angle compensation amount will be described: Based on the real-time angle, the sector number where the current rotor is located is obtained by looking up the angle table, and it is judged whether the sector sequence changes. Among them, the sectors rotated by the rotor are artificially divided into 6 blocks, each block is separated by 60°, and the relationship between each block of sectors and angles is pre-marked. After obtaining the real-time angle, the sector number where the rotor is currently located can be obtained by looking up the angle table.

[0078] If it is found through table lookup that the sector has changed, then read the current angle base value corresponding to the current sector and determine the previous angle base value corresponding to the previous sector. Among them, each sector corresponds to an angle base value. In this embodiment, the values of the angle base values are 30°, 90°, 150°, 210°, 270°, and 330° respectively. Calculate the cumulative angle according to the previous angle base value and the estimated angle. The calculation method of the cumulative angle is the previous angle base value plus the estimated angle. The value range of the cumulative angle is 0 to 360°, and the theoretical value of the estimated angle is 60°. Further, obtain the error value between the cumulative angle and the real-time angle, and judge according to whether the error value exceeds the error threshold. Among them, the calculation method of the error value is the cumulative angle minus the real-time angle, and the error threshold is set to 30°. If it exceeds the error threshold, it means that there is a large fluctuation in the surface motor position, and it is determined that the estimated angle is abnormal and unreliable, and the angle compensation amount is cleared. At this time, the current angle value is equal to the real-time angle. If it does not exceed the error threshold, then calculate the angle compensation amount by weighted calculation according to the real-time angle and the estimated angle. Specifically, the compensation angle = (real-time angle * A + estimated angle * B) / (A + B), where A and B are the weights assigned artificially. At this time, the current angle value is equal to the real-time angle plus the angle compensation amount obtained in this step.

[0079] If it is found through table lookup that the sector has not changed, then further judge whether the estimated angle satisfies being greater than or equal to the estimation threshold; among them, the estimation threshold is equal to 60° + A, and the selection range of A is 0 to 2 times of 60°. If it does not meet the requirement, then jump back to the step of obtaining the sine and cosine position signals. If it meets the requirement, then force the update of the real-time angle, and regard the estimated angle as the rotor position. It can be understood that when the sensor angle does not change for a long time, then force the current rotor position to be the estimated angle to prompt the motor commutation operation. Then, after subtracting the angle error value from the estimated angle, multiply it by the gain coefficient to calculate the angle compensation amount, where the gain coefficient is a value assigned artificially and takes 0.5 in this embodiment.

[0080] Embodiment 2

[0081] See Figure 2, this embodiment provides a rotation measurement system applied to a brushless wiper motor, which is adapted to the brushless wiper motor control method based on sine-cosine position signals as in Embodiment 1. It mainly includes an interface module, a main control module, a drive circuit, a detection module, and a brushless wiper motor.

[0082] Among them, the interface module is electrically connected to the main control module. The interface module includes a power supply interface, a communication interface, and an angle detection interface. Specifically, the external power current will provide power support to the main control module, the drive circuit, and the brushless wiper motor through the power supply interface. Among them, interface KL30 is connected to the positive pole of the power supply, and interface KL31 is connected to the negative pole of the power supply. After the power current passes through interface KL30, it also passes through a filter circuit for filtering and an anti-reverse circuit and then enters the main control module and the energy storage capacitor respectively. After passing through the energy storage capacitor, the power current enters the drive circuit. Interface KL31 is connected to the negative pole of the power supply and is grounded. The external control instruction is input to the main control module after passing through the CAN communication interface and another filter circuit in sequence. The sine-cosine position signals collected by the Hall sensor in Embodiment 1 are transmitted to the main control module through the angle detection interface (angle detection b). And angle detection a transmits the analog signal of the angle sensor arranged at the gear of the brushless wiper motor to the main control module, and this angle sensor can identify the rotation angle of the gear.

[0083] Furthermore, the main control module is also electrically connected to the drive circuit, and can issue a control signal to the drive circuit according to the received control instruction, and receive the angle detection signal to detect the rotation angles of the rotor and the gear of the brushless wiper motor in real time. Specifically, the main control module includes a power module, a boost unit, a clock unit, a PWM generator, a wake-up unit, a communication unit, a storage unit, a microcontroller, a transceiver, an analog-to-digital converter, and a drive protection unit, etc.

[0084] The aforementioned power supply current will enter the power supply module in the main control module, which can provide power management for the entire main control module. The boost unit is used to provide a high voltage to the gate of the MOS transistor in the reverse protection circuit and also to the gate of the high-side MOS transistor of the H-bridge in the drive circuit. The clock unit is used to provide a clock signal to the main control module. The PWM generator is used to generate a PWM signal and input it to the drive circuit. The wake-up unit is used to wake up the microcontroller from the low-power mode to the normal operating mode according to the control instruction. The transceiver is used to receive the control instruction input from the CAN interface. The communication unit is used to process the received control instruction and transmit it to the microcontroller. The storage unit stores the relevant instructions for the microcontroller to run. The microcontroller controls the PWM generator according to the control instruction, the motor current detection signal, the motor temperature detection signal, and the angle detection signal to adjust the operation of the brushless wiper motor. Among them, the microcontroller can execute a brushless wiper motor control method based on the sine-cosine position signal as described in Embodiment 1. The analog-to-digital converter converts the motor current detection signal, the motor temperature detection signal, and the angle detection signal into digital signals recognizable by the microcontroller. Among them, the motor current detection signal is obtained through the current detection circuit of the detection module, and the motor temperature detection signal is obtained through the temperature detection circuit of the detection module. The drive protection unit is used to achieve overcurrent protection by turning off the MOS transistors in the drive circuit. Specifically, overcurrent detection is performed on the upper MOS or lower MOS of the H-bridge in the drive circuit. By setting and detecting the voltage drop of the MOS transistor VDS, it is determined whether the MOS transistor has overcurrent. If it exceeds the preset threshold, the system determines that there is overcurrent, and then turns off the corresponding channel MOS. If it does not exceed the threshold, the system operates normally. The drive circuit is electrically connected to the brushless wiper motor and drives the brushless wiper motor to rotate according to the received control signal.

[0085] Embodiment 3

[0086] Refer to Figure 3 , this embodiment provides a rotation measurement device applied to a brushless wiper motor, which is adapted to the brushless wiper motor control method based on the sine-cosine position signal as in Embodiment 1.

[0087] From a structural perspective, the brushless wiper motor includes: a housing, a drive mechanism, and an output mechanism. The drive mechanism and the output mechanism are arranged inside the housing. As Figure 3 shown, by hiding part of the housing, its internal structure can be visually seen.

[0088] Refer to Figure 3, the drive mechanism will now be described: A transmission rod 7 is provided inside the drive mechanism. One end of the transmission rod 7 extends into the drive mechanism and achieves transmission connection, and the other end of the transmission rod 7 is in transmission connection with the output mechanism. The measurement assembly is connected to the transmission rod 7. The measurement assembly includes a magnetic ring 2 and a Hall sensor 1. The magnetic ring 2 is sleeved on the transmission rod 7 and is arranged close to the drive mechanism side, and the Hall sensor 1 is arranged close to the magnetic ring 2. The Hall sensor 1 and the magnetic ring 2 cooperate with each other to measure the rotation angle of the transmission rod 7 (equivalent to the rotation angle of the rotor 5) in real time, so as to generate a sine-cosine position signal for measuring the rotation of the brushless wiper motor rotor 5, that is, the sine-cosine position signal to be collected in Embodiment 1.

[0089] Preferably, the drive mechanism further includes a stator 4, a rotor 5, an iron core, and a magnet 6. The rotor 5 is arranged inside the drive mechanism. A first circular through hole is opened at the center of the rotor 5, and the iron core is arranged inside the first circular through hole, and one end of the iron core is connected to the transmission rod 7. The magnet 6 is circumferentially attached to the side surface of the rotor 5, and the stator 4 is circumferentially attached to the inner wall of the housing and is arranged corresponding to the magnet 6. One end of the transmission rod 7 extends into the drive mechanism and is in transmission connection with the iron core, and the other end of the transmission rod 7 is in transmission connection with the output mechanism. The stator 4 of the drive mechanism is a coil-wound armature, and the magnet 6 and the rotor 5 form a permanent magnet rotor 5. During implementation, the rotor 5 drives the iron core to make the transmission rod 7 rotate around its own axis.

[0090] Refer to Figure 3 , further, an installation bracket 3 is arranged inside the housing and on the path of the transmission rod 7. The installation bracket 3 is fixed inside the housing. The installation bracket 3 is used to install the circuit board of the above Hall sensor 1, and the Hall sensor 1 is installed on the circuit board. A recessed notch is opened at the top of the above circuit board. The transmission rod 7 passes through the notch and is in transmission connection with the output mechanism. Specifically, the magnetic ring 2 is sleeved on the transmission rod 7, located between the circuit board and the iron core, and is arranged close to the circuit board.

[0091] An output rod 8, a rotating gear 9, and an angle sensor are arranged inside the output mechanism. The rotating gear 9 is in transmission connection with the transmission rod 7. The rotating gear 9 is sleeved on the output rod 8. The angle sensor is arranged at one end of the transmission rod 7 and is used to measure the rotation angle of the rotating gear 9 sleeve in real time. The signal collected by the angle sensor is input to the main control module through the angle detection a in Embodiment 2.

[0092] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, provided that these changes fall within the scope of the claims of the present invention and their equivalent technologies, they still fall within the protection scope of the present invention.

Claims

1. A brushless wiper motor control method based on sine and cosine position signals, applied to real-time detection of rotor position in a brushless wiper motor, characterized in that: The steps include: Obtain the sine and cosine position signals corresponding to the motor rotor angle position at any time; Performing arc tangent calculation on the sine and cosine position signals to obtain the real-time angle of the motor; An estimated angle is obtained by collecting a back electromotive force signal of a brushless wiper motor and calculating the estimated angle, and the real-time angle is compared with the estimated angle to calculate an angle error value; Calculate an optimized and updated angle value based on the real-time angle and the angle compensation amount; The angle compensation amount is calculated as follows: Obtaining the sector number of the current rotor based on the real-time angle table lookup, and determining whether the sector has undergone sequence changes; If there is a change, the current angle base value corresponding to the current sector is read, and the previous angle base value corresponding to the previous sector is determined, the cumulative angle is calculated according to the previous angle base value and the estimated angle, the error value between the cumulative angle and the real-time angle is obtained, and whether the error value exceeds an error threshold is determined. If it exceeds the error threshold, the estimated angle is determined to be abnormal, and the angle compensation amount is cleared; if it does not exceed the error threshold, a weighted calculation is performed according to the real-time angle and the estimated angle to obtain the angle compensation amount; If there is no change, determine whether the estimated angle satisfies or is greater than or equal to the estimation threshold; if not, jump back to the sine and cosine position signal acquisition step; if satisfied, update the real-time angle to the estimated angle, and calculate the angle compensation amount based on the angle error value and the estimated angle.

2. The brushless wiper motor control method based on sine and cosine position signals according to claim 1, characterized in that: The obtained sine and cosine position signals are low-pass filtered and normalized before arc tangent calculation. The calculation formula for arc tangent calculation is: in, is a sinusoidal signal, is a cosine signal.

3. The brushless wiper motor control method based on sine and cosine position signals according to claim 1, characterized in that: By collecting the back electromotive force signal at the stator of the brushless wiper motor, the average rotation time of 60° is calculated based on the time of 360° rotation of the stator of the brushless wiper motor, the angular velocity of the rotor is calculated based on the average rotation time of 60°, and the estimated angle is obtained through the angular velocity calculation of the rotor; The angle error value is calculated by subtracting the real-time angle from the estimated angle.

4. The brushless wiper motor control method based on sine and cosine position signals according to claim 1, characterized in that: The sector in which the rotor rotates is divided into 6 sectors, each sector is 60° apart, the relationship between each sector and the angle is marked in advance, and the sector number of the rotor at the real-time angle is obtained by looking up the angle table.

5. The brushless wiper motor control method based on sine and cosine position signals according to claim 1, characterized in that: After determining that the sector has changed, the cumulative angle is calculated by adding the previous angle base value to the estimated angle, the error value is calculated by subtracting the real-time angle from the cumulative angle, and it is determined whether the error value exceeds the error threshold, wherein the error threshold is set to 30°; If the error threshold is exceeded, it is determined that the brushless wiper motor fluctuates, the estimated angle is abnormal data, and the angle compensation amount is cleared, and the current angle value is equal to the real-time angle; If the error threshold is not exceeded, the angle compensation amount is calculated by weighted calculation of the real-time angle and the estimated angle, and the real-time angle plus the angle compensation amount is added to obtain the current angle value.

6. The brushless wiper motor control method based on sine and cosine position signals according to claim 1, characterized in that: After determining that the sector has not changed, further determining whether the estimated angle satisfies or is greater than or equal to an estimated threshold; wherein the estimation threshold selection range is 60 to 180°; If not satisfied, jump back to the step of acquiring the sine and cosine position signals; If the conditions are met, the real-time angle is forced to be updated, the estimated angle is identified as the rotor position, and the angle compensation is calculated. The angle compensation is calculated by subtracting the angle error value from the estimated angle and then multiplying the result by a gain coefficient.

7. A brushless wiper motor control system based on sine-cosine position signals, adapted to the brushless wiper motor control method based on sine-cosine position signals as claimed in any one of claims 1 to 6, characterized in that: include: Interface module, main control module, drive circuit, detection module and brushless wiper motor; The interface module is electrically connected to the main control module, and the interface module includes a power supply interface, a communication interface, and an angle detection interface. The interface module provides power support to the main control module, the drive circuit, and the brushless wiper motor via the power supply interface, transmits control instructions to the main control module via the communication interface, and transmits an angle detection signal to the main control module via the angle detection interface; wherein the angle detection signal includes a sine and cosine position signal of an angle sensor at a rotor of the brushless wiper motor, and an analog signal of an angle sensor at a gear of the brushless wiper motor; The main control module is also electrically connected to the drive circuit, and is configured to send a control signal to the drive circuit according to a control instruction, and receive an angle detection signal to perform real-time detection of the rotation angle of the rotor and gear of the brushless wiper motor; The driving circuit is electrically connected to the brushless wiper motor and is configured to receive a control signal to drive the brushless wiper motor to rotate; The detection module is electrically connected to the main control module and the driving circuit respectively, and is configured to detect and transmit a motor current detection signal and a motor temperature detection signal to the main control module.

8. The brushless wiper motor control system based on sine and cosine position signals according to claim 7, characterized in that: The main control module includes a power module, a boost unit, a clock unit, a PWM generator, a wake-up unit, a communication unit, a storage unit, a microcontroller, a transceiver, an analog-to-digital converter and a drive protection unit; The power supply module is electrically connected to the power supply interface and is configured to provide power management for the main control module; The boost unit is configured to provide a high voltage to the gate of the H-bridge high-side MOS tube of the driving circuit; The clock unit is configured to provide a clock signal to the main control module; The PWM generator is configured to generate a PWM signal to be input to the driving circuit; The wake-up unit is configured to wake up the microcontroller from a low power consumption mode to a normal working mode; The transceiver is configured to receive a control instruction; The communication unit is configured to perform signal processing on the received control instruction and transmit the signal to the microcontroller; The storage unit is configured to store relevant instructions for the microcontroller to execute; The microcontroller is configured to control the PWM generator according to the control instruction, the motor current detection signal, the motor temperature detection signal and the angle detection signal to adjust the operation of the brushless wiper motor; The analog-to-digital converter is configured to convert the motor current detection signal, the motor temperature detection signal and the angle detection signal into digital signals recognizable by the microcontroller; The driving protection unit is configured to achieve over-current protection by turning off the MOS tube in the driving circuit.

9. A brushless wiper motor control device based on sine-cosine position signals, adapted to the brushless wiper motor control method based on sine-cosine position signals as claimed in any one of claims 1 to 6, characterized in that: The brushless wiper motor comprises: an outer shell, a driving mechanism and an output mechanism, wherein the driving mechanism and the output mechanism are arranged in the outer shell; a transmission rod is arranged in the driving mechanism, one end of the transmission rod extends into the driving mechanism and realizes transmission connection, and the other end of the transmission rod is transmission connected with the output mechanism; A measuring assembly connected to the transmission rod is also provided, the measuring assembly includes a magnetic ring and a Hall sensor, the magnetic ring is sleeved on the transmission rod and arranged close to one side of the driving mechanism, the Hall sensor is arranged close to the magnetic ring, the Hall sensor cooperates with the magnetic ring, and is configured to measure the rotation angle of the transmission rod in real time to generate a sine and cosine position signal for measuring the rotation of the brushless wiper motor rotor; The output mechanism is provided with an output rod, a rotating gear and an angle sensor. The rotating gear is in transmission connection with the transmission rod, and the rotating gear is sleeved on the output rod. The angle sensor is configured to measure the rotation angle of the rotating gear in real time.

10. The brushless wiper motor control device based on sine and cosine position signals according to claim 9, characterized in that: The driving mechanism also includes a stator, a rotor, an iron core and a magnet; The iron core is connected to the transmission rod; A first circular through hole is opened at the center of the rotor, and the iron core is arranged in the first circular through hole; The magnet surrounds and fits on the side surface of the rotor; The stator is circumferentially attached to the inner wall of the outer shell and is arranged corresponding to the magnet.

11. The brushless wiper motor control device based on sine and cosine position signals according to claim 10, characterized in that: A mounting frame is provided in the outer shell and on the path of the transmission rod, the mounting frame is fixed to the inside of the outer shell, and the mounting frame is configured to install a Hall sensor circuit board; the Hall sensor is installed on the Hall sensor circuit board, and an inwardly recessed notch is provided on the top of the Hall sensor circuit board, and the transmission rod passes through the notch to be transmission-connected to the output mechanism; the magnetic ring is sleeved on the transmission rod, located between the Hall sensor circuit board and the iron core, and is arranged close to the Hall sensor circuit board.

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