Intelligent turn signal control system and control method thereof

Abstract

The present invention proposes an intelligent turn signal control system and a control method thereof. By setting up multiple magnetic sensors to detect the steering wheel rotation angle, the detection accuracy can be improved. By optimizing the installation position of the magnetic sensors, on the one hand, since the three magnetic sensors are not arranged on the same straight line, the mutual interference between the magnetic sensors can be reduced. On the other hand, when the steering wheel turns left or right, the angles detected by the three magnetic sensors are opposite. Therefore, an angle error range can be set. When the angle detected by the three magnetic sensors is less than the preset angle error range, the detected angle is valid; otherwise, the detected angle is invalid.

Description

Technical Field

[0001] The present invention relates to the field of intelligent turn signal lamps, and in particular to an intelligent turn signal lamp control system and a control method thereof. Background Art

[0002] At present, the turn signals of vehicles on the market are basically manually controlled. After the driver triggers the turn, if the turn signal does not return to its original position in time after the turn is completed and the straight line is driven, the vehicle behind may misjudge the driver's driving intention, which can easily lead to an accident. Another possibility is that the driver forgets to trigger the turn signal when turning, resulting in the vehicle behind not noticing in time, which can also easily lead to an accident. Existing intelligent turn signals generally detect the steering wheel rotation angle through a magnetic sensor, and judge the current driver's driving intention based on the rotation angle and the switching value of the turn signal. When the turn signal does not match the driving intention, the processing unit controls the corresponding turn signal to turn on or off to ensure driving regulations. However, there are mechanical errors and mutual assembly errors in magnetic sensors, which lead to large deviations in the detection angle. Therefore, in order to solve the above problems, the present invention provides an intelligent turn signal control system and a control method thereof, which uses error calibration and compensation methods to ensure that the output angle of the magnetic sensor is close to the actual angle. Summary of the Invention

[0003] In view of this, the present invention proposes an intelligent turn signal control system and a control method thereof, which uses error calibration and compensation methods to ensure that the output angle of the magnetic sensor approaches the actual angle.

[0004] The technical solution of the present invention is implemented as follows: On the one hand, the present invention provides an intelligent turn signal control system, which includes a processor and a permanent magnet, and also includes a first magnetic sensor, a second magnetic sensor and a third magnetic sensor;

[0005] The permanent magnet is fixedly mounted on a rotating shaft of a vehicle steering gear, and the N pole and S pole of the permanent magnet are arranged along the axial direction of the rotating shaft. The first magnetic sensor, the second magnetic sensor, and the third magnetic sensor are arranged on a fixed bracket of the vehicle steering gear at circumferential positions with the rotating shaft of the vehicle steering gear as the center. The first magnetic sensor is arranged directly opposite the static permanent magnet, and the second magnetic sensor and the third magnetic sensor are symmetrically arranged on both sides of the first magnetic sensor in a direction facing the permanent magnet.

[0006] The first magnetic sensor, the second magnetic sensor and the third magnetic sensor are electrically connected to the processor respectively.

[0007] On the basis of the above technical solution, preferably, it further includes a turn signal driving unit and a switch detection unit;

[0008] The input end of the switch detection unit is electrically connected to the left turn button switch and the right turn button switch respectively, and the output end of the switch detection unit is electrically connected to the GPIO port of the processor; the input end of the turn signal drive unit is electrically connected to the GPIO port of the processor, and the output end of the turn signal drive unit is electrically connected to the left turn signal and the right turn signal respectively.

[0009] On the basis of the above technical solution, preferably, the switch detection unit includes a left turn signal switch detection unit and a right turn signal switch detection unit;

[0010] The input end of the left turn signal switch detection unit is electrically connected to the left turn signal button switch, and the output end of the left turn signal switch detection unit is electrically connected to the GPIO port of the processor;

[0011] The input end of the right turn signal switch detection unit is electrically connected to the right turn signal key switch, and the output end of the right turn signal switch detection unit is electrically connected to the GPIO port of the processor.

[0012] On the basis of the above technical solution, preferably, the left turn signal switch detection unit includes: capacitor C23, capacitor C353, resistor R47 and diode D28;

[0013] The GPIO port of the processor is electrically connected to the left turn button switch through a forward-conducting diode D28, one end of capacitor C23 is electrically connected to the GPIO port of the processor, and the other end of capacitor C23 is grounded; the power supply is electrically connected to the GPIO port of the processor through resistor R47; one end of capacitor C353 is electrically connected to the cathode of diode D28, and the other end of capacitor C353 is grounded.

[0014] On the basis of the above technical solution, preferably, the turn signal driving unit includes a left turn signal driving unit and a right turn signal driving unit;

[0015] The input end of the left turn signal driving unit is electrically connected to the GPIO port of the processor, and the output end of the left turn signal driving unit is electrically connected to the left turn signal;

[0016] The input end of the right turn signal driving unit is electrically connected to the GPIO port of the processor, and the output end of the right turn signal driving unit is electrically connected to the right turn signal.

[0017] On the basis of the above technical solution, preferably, the left turn signal driving unit includes: a resistor R112, a resistor R113 and a MOS tube Q22;

[0018] The GPIO port of the processor is electrically connected to the gate of the MOS transistor Q22 through the resistor R112. The source of the MOS transistor Q22 is grounded, and the drain of the MOS transistor Q22 is electrically connected to the left turn signal. One end of the resistor R113 is electrically connected to the gate of the MOS transistor Q22, and the other end of the resistor R113 is grounded.

[0019] In another aspect, the present invention provides a control method for an intelligent turn signal control system, comprising the following steps:

[0020] S1. Rotate the steering wheel clockwise and counterclockwise with a step size of 0.1° and an angle detection range of ±360°. Obtain the sensing signals output by the first, second, and third magnetic sensors and their corresponding angles. Establish clockwise output angle error curve Y1(x) and counterclockwise output angle error curve Y2(x).

[0021] S2. Calculate the average line of the curve Y1(x) and the curve Y2(x), and the average of the two average lines, respectively. The average is recorded as the average offset;

[0022] S3. Determine the difference between the curve Y1(x) and the average offset as the curve after the curve Y1(x) is corrected, and determine the difference between the curve Y2(x) and the average offset as the curve after the curve Y2(x) is corrected;

[0023] S4. Set a straight-ahead tolerance angle and a turning angle threshold, determine a steering wheel rotation angle based on the corrected curve, and judge the current driver's driving intention based on the steering wheel rotation angle and the on / off value of the turn signal. When the turn signal does not match the driving intention, the controller controls the corresponding turn signal to turn on or off.

[0024] Based on the above technical solution, preferably, before executing S1, the following steps are further included: obtaining induction signals output by the first magnetic sensor, the second magnetic sensor, and the third magnetic sensor when the permanent magnet is in a static state, and calculating the static angle corresponding to the induction signals;

[0025] The actual steering wheel rotation angle is obtained by subtracting the static angle from the rotation angle determined based on the corrected curve in S4.

[0026] Based on the above technical solution, preferably, the average lines of the curve Y1(x) and the curve Y2(x) in S2 are respectively:

[0027]

[0028]

[0029] Where, represents the mean line of the curve Y1(x); Y1' represents the linear slope of the curve Y1(x); represents the average line of the curve Y2(x); Y2' represents the linear slope of the curve Y2(x); and x represents the target angle value.

[0030] Based on the above technical solution, preferably, S3 further includes the following steps: dividing the angle detection range into a plurality of units, performing linear fitting on the local data in each unit to determine its average error value; and using the deviation between the average error value and the actual angle as the angle compensation value of the unit;

[0031] S4 deducts the static angle from the rotation angle determined based on the corrected curve and then deducts the angle compensation amount to obtain the actual steering wheel rotation angle.

[0032] The intelligent turn signal control system and control method of the present invention have the following beneficial effects compared with the prior art:

[0033] (1) By setting up multiple magnetic sensors to detect the steering wheel rotation angle, the detection accuracy can be improved;

[0034] (2) By optimizing the installation position of the magnetic sensors, on the one hand, since the three magnetic sensors are not arranged on the same straight line, the mutual interference between the magnetic sensors can be reduced; on the other hand, when the steering wheel turns left or right, the angles detected by the three magnetic sensors are opposite, so the angle error range can be set. When the angle detected by the three magnetic sensors is less than the preset angle error range, the detected angle is valid, otherwise the detected angle is invalid;

[0035] (3) Based on the average offset, the clockwise output angle error curve Y1(x) and the counterclockwise output angle error curve Y2(x) are corrected to make the two curves closer to the target angle value and reduce the average hysteresis index of the two curves to

[0036] (4) By calibrating the static angle corresponding to the mechanical zero point of the magnetic sensor, the influence of the angle generated by the steering wheel at the zero point on the measurement result can be eliminated by subtracting the static angle when calculating the steering wheel rotation angle, thereby reducing the detection error;

[0037] (5) By dividing the angle detection range into several units, a linear fit is performed on the local data in each unit to determine its average error value. The offset between the average error value and the actual angle is used as the angle compensation of the unit. Nonlinearity compensation can be performed to ensure the smoothness of the corrected curves Y1(x) and Y2(x), and reduce the probability of the magnetic sensor output angle jumping due to the nonlinearity deviation. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0039] Figure 1 This is a structural diagram of an intelligent turn signal control system of the present invention;

[0040] Figure 2 This is a circuit diagram of a turn signal drive unit in an intelligent turn signal control system of the present invention;

[0041] Figure 3 The circuit diagram of a switch detection unit in an intelligent turn signal control system of the present invention is shown. DETAILED DESCRIPTION

[0042] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0043] Example 1

[0044] Currently, a magnetic sensor is used to detect the direction of steering wheel rotation, which can only detect the angle of one azimuth and cannot meet the detection of left and right turns of the steering wheel. Therefore, in order to solve the above problems, this embodiment provides an intelligent turn signal control system, which includes a processor, a permanent magnet and a plurality of magnetic sensors. Among them, the permanent magnet is fixedly set on the rotating shaft of the vehicle steering gear and the N pole and S pole of the permanent magnet are set along the axial direction of the rotating shaft, and a plurality of magnetic sensors are evenly and equidistantly set on the fixed bracket of the vehicle steering gear; and a plurality of magnetic sensors are electrically connected to the processor respectively. By setting up a plurality of magnetic sensors, the direction of steering wheel rotation can be detected, and the plurality of magnetic sensors are mutually verified to avoid the failure of a single magnetic sensor causing the system to be unable to recognize the steering wheel rotation angle.

[0045] Preferably, this embodiment includes three magnetic sensors, namely a first magnetic sensor, a second magnetic sensor, and a third magnetic sensor. Since the magnetic fields of the three magnetic sensors interfere with each other, causing large errors in the measured angle, in this embodiment, the installation positions of the three magnetic sensors are limited. Specifically, the first magnetic sensor, the second magnetic sensor, and the third magnetic sensor are arranged on a circle centered on the vehicle steering shaft. The first magnetic sensor is arranged directly opposite a static permanent magnet, and the second magnetic sensor and the third magnetic sensor are symmetrically arranged on both sides of the first magnetic sensor in the direction facing the permanent magnet. The first magnetic sensor, the second magnetic sensor, and the third magnetic sensor are electrically connected to the processor, respectively. The first magnetic sensor detects the static angle of the steering wheel, the second magnetic sensor detects the left-turn angle of the steering wheel, and the third magnetic sensor detects the right-turn angle of the steering wheel. The three magnetic sensors can detect the direction of steering wheel rotation. The first, second, and third magnetic sensors are arranged on a circle centered on the vehicle's steering shaft. Since the three magnetic sensors are not arranged on the same straight line, mutual interference between the magnetic sensors can be reduced. Furthermore, when the steering wheel turns left or right, the angles detected by the three magnetic sensors are opposite. Therefore, an angle error range can be set. When the angles detected by the three magnetic sensors are less than the preset angle error range, the detected angle is valid; otherwise, the detected angle is invalid. Preferably, the first, second, and third magnetic sensors all use an integrated 3-axis magnetic sensor chip, HMC5883.

[0046] Preferably, it also includes a switch detection unit for detecting the switch status of the left turn signal button switch and the right turn signal button switch, so as to determine the driver's driving intention of turning left, turning right, or going straight. In this embodiment, the switch detection unit includes a left turn signal switch detection unit and a right turn signal switch detection unit; the input end of the left turn signal switch detection unit is electrically connected to the left turn signal button switch, and the output end of the left turn signal switch detection unit is electrically connected to the GPIO port of the processor; the input end of the right turn signal switch detection unit is electrically connected to the right turn signal button switch, and the output end of the right turn signal switch detection unit is electrically connected to the GPIO port of the processor. Further preferably, the left turn signal switch detection unit and the right turn signal switch detection unit have the same structure, and only the structure and principle of the left turn signal switch detection unit are introduced here. Specifically, if Figure 3As shown, the left turn signal switch detection unit includes capacitor C23, capacitor C353, resistor R47, and diode D28. The processor's GPIO port is electrically connected to the left turn signal switch via the forward-conducting diode D28. One end of capacitor C23 is electrically connected to the processor's GPIO port, and the other end of capacitor C23 is grounded. A power supply is electrically connected to the processor's GPIO port via resistor R47. One end of capacitor C353 is electrically connected to the cathode of diode D28, and the other end of capacitor C353 is grounded. DIN3 represents the left turn signal switch, and DIN_03 represents the processor's GPIO port. DIN4 represents the right turn signal switch, and DIN_04 represents the processor's GPIO port. When the left turn signal switch is closed, the cathode potential of diode D28 drops, forming a voltage difference between the cathode and anode of diode D28. This voltage difference satisfies the conduction condition for diode D28. At this point, diode D28 is turned on, and an analog signal is input to the processor's GPIO port.

[0047] Preferably, a turn signal driving unit is further included to drive the turn signal on or off. In this embodiment, the turn signal driving unit includes a left turn signal driving unit and a right turn signal driving unit; the input end of the left turn signal driving unit is electrically connected to the GPIO port of the processor, and the output end of the left turn signal driving unit is electrically connected to the left turn signal; the input end of the right turn signal driving unit is electrically connected to the GPIO port of the processor, and the output end of the right turn signal driving unit is electrically connected to the right turn signal. More preferably, as Figure 2 As shown, the left turn signal driver unit and the right turn signal driver unit have the same structure. Here, only the structure and operating principle of the left turn signal driver unit are described. Specifically, the left turn signal driver unit includes resistors R112 and R113, and a MOSFET Q22. The processor's GPIO port is electrically connected to the gate of MOSFET Q22 via resistor R112. The source of MOSFET Q22 is grounded, and the drain of MOSFET Q22 is electrically connected to the left turn signal. One end of resistor R113 is electrically connected to the gate of MOSFET Q22, and the other end of resistor R113 is grounded. MOUT14 and MOUT15 represent the processor's GPIO ports, and OUT14 and OUT15 represent the terminals connected to the left and right turn signals, respectively. When the processor's GPIO port outputs a control signal to the gate of MOSFET Q22, MOSFET Q22 turns on, and the control signal is output to the left turn signal via MOSFET Q22, turning it on.

[0048] The working principle of this embodiment is as follows: when the processor receives the driver's intention to turn on the left or right turn signal through the switch detection unit, the processor flashes the corresponding turn signal through the turn signal driving unit;

[0049] When the processor receives the driver's intention to turn off the left or right turn signal through the switch detection unit, the processor turns off the corresponding turn signal through the turn signal drive unit;

[0050] When the turn signal flashes to indicate a vehicle turn, and the first magnetic sensor, the second magnetic sensor, and the third magnetic sensor detect that the vehicle returns from a turning state greater than a preset turning angle to a straight-moving state less than a preset straight-moving tolerance angle range, the processor turns off the corresponding turn signal through the turn signal driving unit;

[0051] When the processor detects that the vehicle is turning left at a angle greater than the preset angle, it will automatically turn on the left turn signal even if the driver does not give it a left turn command.

[0052] When the processor detects that the vehicle is in a right turn state greater than a preset steering angle, it can automatically turn on the right turn signal and flash it even if it does not receive a right turn command from the driver.

[0053] The beneficial effects of this embodiment are: by providing multiple magnetic sensors to detect the steering wheel rotation angle, the detection accuracy can be improved;

[0054] By optimizing the installation positions of the magnetic sensors, on the one hand, since the three magnetic sensors are not arranged on the same straight line, the mutual interference between the magnetic sensors can be reduced; on the other hand, when the steering wheel turns left or right, the angles detected by the three magnetic sensors are opposite. Therefore, an angle error range can be set. When the angles detected by the three magnetic sensors are less than the preset angle error range, the detected angle is valid, otherwise the detected angle is invalid.

[0055] Example 2

[0056] The magnetic sensors used in Example 1 have mechanical errors and mutual assembly errors, resulting in large deviations in the detection angle. Therefore, to solve the above problems, this embodiment provides a method for reducing the detection angle error, which specifically includes the following steps:

[0057] S1. Rotate the steering wheel clockwise and counterclockwise with a step size of 0.1° and an angle detection range of ±360°. Obtain the sensing signals output by the first, second, and third magnetic sensors and their corresponding angles. Establish clockwise output angle error curve Y1(x) and counterclockwise output angle error curve Y2(x).

[0058] Note that x represents the target angle; Y1(x) represents the error between the measured and actual angles when the steering wheel is turned clockwise; and Y2(x) represents the error between the measured and actual angles when the steering wheel is turned counterclockwise. Because the second and third magnetic sensors are symmetrically positioned with respect to the first magnetic sensor, the clockwise and counterclockwise output angle error curves Y1(x) and Y2(x) can be cross-referenced.

[0059] S2. Calculate the average line of the curve Y1(x) and the curve Y2(x), and the average of the two average lines, respectively. The average is recorded as the average offset;

[0060] It should be noted that the method for obtaining the average line of curve Y1(x) and curve Y2(x) is to perform a straight line fit on curve Y1(x) and curve Y2(x), and the fitted straight line is the corresponding average line. In this embodiment, the average lines of curve Y1(x) and curve Y2(x) are: Where, represents the mean line of the curve Y1(x); Y1' represents the linear slope of the curve Y1(x); represents the average line of the curve Y2(x); Y2' represents the first slope of the curve Y2(x). Preferably, the mean of the two average lines is:

[0061] S3. Determine the difference between the curve Y1(x) and the average offset as the curve after the curve Y1(x) is corrected, and determine the difference between the curve Y2(x) and the average offset as the curve after the curve Y2(x) is corrected;

[0062] It should be noted that the average offset obtained in steps S1-S3 can be used to correct the clockwise output angle error curve Y1(x) and the counterclockwise output angle error curve Y2(x), so that the two curves are closer to the target angle value and the average hysteresis index of the two curves is reduced to

[0063] S4. Set a straight-ahead tolerance angle and a turning angle threshold, determine a steering wheel rotation angle based on the corrected curve, and judge the current driver's driving intention based on the steering wheel rotation angle and the on / off value of the turn signal. When the turn signal does not match the driving intention, the controller controls the corresponding turn signal to turn on or off.

[0064] The beneficial effects of this embodiment are as follows: by correcting the clockwise output angle error curve Y1(x) and the counterclockwise output angle error curve Y2(x) based on the average offset, the two curves can be made closer to the target angle value, and the average hysteresis index of the two curves can be reduced to

[0065] Example 3

[0066] In the process of calculating the steering wheel angle based on Example 2, it is necessary to base it on a certain base point, which is generally defined as the mechanical zero point of the steering wheel, that is, the angle corresponding to the static state of the steering wheel, and the theoretical value of this angle is 0. However, during the installation process or use of the magnetic sensor, the steering wheel may have a deflection angle when it is static, resulting in the calculated steering wheel rotation angle being greater than the actual angle. Even if the method described in Example 2 is used, this error cannot be eliminated. Therefore, in order to solve the above problem, this embodiment provides a method for zero-point calibration of the sensor. First, the zero-point angle value of the magnetic sensor is calibrated. When calculating the steering wheel rotation angle, the zero-point angle value is subtracted to eliminate the influence of the angle generated by the steering wheel at the zero position on the measurement result. The specific implementation process is as follows:

[0067] S1. Obtaining induction signals output by the first magnetic sensor, the second magnetic sensor, and the third magnetic sensor when the permanent magnet is in a static state, and calculating a static angle corresponding to the induction signals;

[0068] S2. Rotate the steering wheel clockwise and counterclockwise with a step size of 0.1° and an angle detection range of ±360°. Obtain the sensing signals output by the first, second, and third magnetic sensors and their corresponding angles, and establish a clockwise output angle error curve Y1(x) and a counterclockwise output angle error curve Y2(x).

[0069] S3. Calculate the average line of the curve Y1(x) and the curve Y2(x), and the average of the two average lines, respectively. The average is recorded as the average offset.

[0070] S4. Determine the difference between the curve Y1(x) and the average offset as the curve after the curve Y1(x) is corrected, and determine the difference between the curve Y2(x) and the average offset as the curve after the curve Y2(x) is corrected;

[0071] It should be noted that steps S2-S4 are the same as those in Example 2 and will not be repeated here.

[0072] S5. Set a straight-ahead tolerance angle and a steering angle threshold. Subtract the static angle from the steering angle determined based on the corrected curve to obtain the final steering wheel steering angle. Determine the current driver's driving intention based on the steering wheel steering angle and the on / off value of the turn signal. When the turn signal does not match the driving intention, the controller controls the corresponding turn signal to turn on or off.

[0073] It should be noted that this step is different from step S4 in embodiment 2. In this step, the rotation angle determined based on the corrected curve needs to be subtracted from the static angle to obtain the actual rotation angle of the steering wheel.

[0074] The beneficial effect of this embodiment is: by calibrating the static angle corresponding to the mechanical zero point of the magnetic sensor, the influence of the angle generated by the steering wheel at the zero point position on the measurement result can be eliminated by subtracting the static angle when calculating the steering wheel rotation angle, thereby reducing the detection error.

[0075] Example 4

[0076] The clockwise output angle error curve Y1(x) and the counterclockwise output angle error curve Y2(x) obtained in Example 2-3 have a one-to-one correspondence with their respective corrected curves. At this time, after eliminating the nonlinear offset at each position point, the corrected curve Y1(x) and the corrected curve Y2(x) can be compensated for nonlinearity. However, Example 2-3 uses a step size of 0.1° and an angle detection range of ±360°. Therefore, data compensation is required for 721 position points, and the amount of compensation data is large. Therefore, in order to reduce the amount of compensation data, this embodiment provides a method for quickly performing nonlinear compensation based on Example 3, which specifically includes the following steps:

[0077] S1. Obtaining induction signals output by the first magnetic sensor, the second magnetic sensor, and the third magnetic sensor when the permanent magnet is in a static state, and calculating a static angle corresponding to the induction signals;

[0078] S2. Rotate the steering wheel clockwise and counterclockwise with a step size of 0.1° and an angle detection range of ±360°. Obtain the sensing signals output by the first, second, and third magnetic sensors and their corresponding angles, and establish a clockwise output angle error curve Y1(x) and a counterclockwise output angle error curve Y2(x).

[0079] S3. Calculate the average line of the curve Y1(x) and the curve Y2(x), and the average of the two average lines, respectively. The average is recorded as the average offset.

[0080] S4. Determine the difference between the curve Y1(x) and the average offset as the curve after the curve Y1(x) is corrected, and determine the difference between the curve Y2(x) and the average offset as the curve after the curve Y2(x) is corrected;

[0081] The angle detection range is divided into several units, and a linear fit is performed on the local data in each unit to determine its average error value; the offset between the average error value and the actual angle is used as the angle compensation value of the unit;

[0082] Preferably, this embodiment uses 200 units, and the length of each unit is 3.6°. That is, this embodiment performs a straight line fitting with data within the range of 3.6°, and only needs to perform 200 data compensations.

[0083] S5. Set a straight-ahead tolerance angle and a steering angle threshold. Subtract the static angle from the steering angle determined based on the corrected curve and then subtract the angle compensation amount to obtain the final steering wheel steering angle. Determine the current driver's driving intention based on the steering wheel steering angle and the on / off value of the turn signal. When the turn signal does not match the driving intention, the controller controls the corresponding turn signal to turn on or off.

[0084] It should be noted that this step is different from step S5 in embodiment 3. In this step, the actual steering wheel rotation angle is obtained by subtracting the static angle from the rotation angle determined based on the corrected curve and then subtracting the angle compensation amount.

[0085] The beneficial effects of this embodiment are as follows: by dividing the angle detection range into several units, performing linear fitting on the local data in each unit, determining its average error value, and using the offset between the average error value and the actual angle as the angle compensation amount of the unit, nonlinearity compensation can be performed to ensure the smoothness of the corrected curves Y1(x) and Y2(x), and reduce the probability of the magnetic sensor output angle jumping due to the nonlinearity deviation.

[0086] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A control method for an intelligent turn signal control system, the intelligent turn signal control system comprising a processor and a permanent magnet, characterized in that: Also included are a first magnetic sensor, a second magnetic sensor, and a third magnetic sensor; The permanent magnet is fixedly mounted on the rotating shaft of the vehicle steering gear, and the N pole and S pole of the permanent magnet are arranged along the axial direction of the rotating shaft. The first magnetic sensor, the second magnetic sensor, and the third magnetic sensor are arranged on a fixed bracket of the vehicle steering gear at circumferential positions with the rotating shaft of the vehicle steering gear as the center. The first magnetic sensor is arranged facing the static permanent magnet, and the second magnetic sensor and the third magnetic sensor are symmetrically arranged on both sides of the first magnetic sensor facing the permanent magnet. The first magnetic sensor, the second magnetic sensor and the third magnetic sensor are electrically connected to the processor respectively; The following steps are involved: S1. Rotate the steering wheel clockwise and counterclockwise with a step size of 0.1° and an angle detection range of ±360°. Obtain the sensing signals output by the first, second, and third magnetic sensors and their corresponding angles. Establish clockwise output angle error curve Y1(x) and counterclockwise output angle error curve Y2(x). S2. Calculate the average line of the curve Y1(x) and the curve Y2(x), and the average of the two average lines, respectively. The average is recorded as the average offset; S3. Determine the difference between the curve Y1(x) and the average offset as the curve after the curve Y1(x) is corrected, and determine the difference between the curve Y2(x) and the average offset as the curve after the curve Y2(x) is corrected; S4. Setting a straight-ahead tolerance angle and a turning angle threshold, determining a steering wheel rotation angle based on the corrected curve, and judging the current driver's driving intention based on the steering wheel rotation angle and the on / off value of the turn signal. When the turn signal does not match the driving intention, the controller controls the corresponding turn signal to turn on or off. Before executing S1, the following steps are also included: obtaining induction signals output by the first magnetic sensor, the second magnetic sensor, and the third magnetic sensor when the permanent magnet is in a static state, and calculating the static angle corresponding to the induction signals; The actual steering wheel rotation angle is obtained by subtracting the static angle from the rotation angle determined based on the corrected curve in S4; The average lines of the curve Y1(x) and the curve Y2(x) in S2 are respectively: Where, represents the mean line of the curve Y1(x); Y1' represents the linear slope of the curve Y1(x); represents the average line of the curve Y2(x); Y2' represents the linear slope of the curve Y2(x); and x represents the target angle value.

2. The control method of the intelligent turn signal control system according to claim 1, characterized in that: It also includes a turn signal drive unit and a switch detection unit; The input end of the switch detection unit is electrically connected to the left turn button switch and the right turn button switch respectively, and the output end of the switch detection unit is electrically connected to the GPIO port of the processor; the input end of the turn signal drive unit is electrically connected to the GPIO port of the processor, and the output end of the turn signal drive unit is electrically connected to the left turn signal and the right turn signal respectively.

3. The control method of the intelligent turn signal control system according to claim 2, characterized in that: The switch detection unit includes a left turn signal switch detection unit and a right turn signal switch detection unit; The input end of the left turn signal switch detection unit is electrically connected to the left turn signal button switch, and the output end of the left turn signal switch detection unit is electrically connected to the GPIO port of the processor; The input end of the right turn signal switch detection unit is electrically connected to the right turn signal key switch, and the output end of the right turn signal switch detection unit is electrically connected to the GPIO port of the processor.

4. The control method of the intelligent turn signal control system according to claim 3, characterized in that: The left turn signal switch detection unit includes: capacitor C23, capacitor C353, resistor R47 and diode D28; The GPIO port of the processor is electrically connected to the left turn button switch through a forward-conducting diode D28, one end of the capacitor C23 is electrically connected to the GPIO port of the processor, and the other end of the capacitor C23 is grounded; the power supply is electrically connected to the GPIO port of the processor through a resistor R47; one end of the capacitor C353 is electrically connected to the cathode of the diode D28, and the other end of the capacitor C353 is grounded.

5. The control method of the intelligent turn signal control system according to claim 2, characterized in that: The turn signal driving unit includes a left turn signal driving unit and a right turn signal driving unit; The input end of the left turn signal driving unit is electrically connected to the GPIO port of the processor, and the output end of the left turn signal driving unit is electrically connected to the left turn signal; The input end of the right turn signal driving unit is electrically connected to the GPIO port of the processor, and the output end of the right turn signal driving unit is electrically connected to the right turn signal.

6. The control method of the intelligent turn signal control system according to claim 5, characterized in that: The left turn signal driving unit includes: a resistor R112, a resistor R113 and a MOS tube Q22; The GPIO port of the processor is electrically connected to the gate of the MOS transistor Q22 through the resistor R112. The source of the MOS transistor Q22 is grounded, and the drain of the MOS transistor Q22 is electrically connected to the left turn signal. One end of the resistor R113 is electrically connected to the gate of the MOS transistor Q22, and the other end of the resistor R113 is grounded.

7. The control method of the intelligent turn signal control system according to claim 1, characterized in that: Said S3 further comprises the following steps: dividing the angle detection range into a plurality of units, performing linear fitting on the local data in each unit to determine its average error value; and using the deviation between the average error value and the actual angle as the angle compensation value of the unit; The S4 subtracts the static angle from the rotation angle determined based on the corrected curve and then subtracts the angle compensation amount to obtain the actual steering wheel rotation angle.

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