Wireless wheel speed meter speed measurement method based on accelerometer and magnetometer and related equipment

Abstract

The invention relates to the technical field of vehicle wheel speed measurement, in particular to a wireless wheel speed meter speed measurement method based on an accelerometer and a magnetometer and related equipment, and the method comprises the steps: obtaining the target distance between the accelerometer and the center of a vehicle rotating shaft and the rotating speed of the vehicle rotating shaft; acquiring a target acceleration based on the target distance and the rotating speed; based on the target acceleration, acquiring accelerometer data; acquiring a first angle corresponding to the accelerometer based on the accelerometer data; acquiring magnetic field meter data; acquiring a second angle corresponding to the magnetometer based on the magnetometer data; acquiring a target angle based on the first angle and the second angle; acquiring a target angular velocity based on the target angle; and outputting the target angular velocity. According to the invention, the accuracy of wheel speed measurement can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of vehicle wheel speed measurement, and in particular to a wireless wheel speedometer speed measurement method based on an accelerometer and a magnetic field meter and related equipment. Background Art

[0002] Accurately measuring wheel speed during vehicle operation is crucial for vehicle safety and stability. Traditional wheel speed measurement methods primarily involve installing a component with a ring gear near the wheel. As the ring gear rotates with the wheel, it cuts through the sensor's magnetic field, generating an induced electromotive force. By detecting the frequency of this induced electromotive force, the wheel speed can be calculated.

[0003] However, the traditional wheel speed measurement method has a relatively simple measurement form and is greatly affected by external electromagnetic interference. The measurement accuracy will decrease in complex electromagnetic environments, resulting in the accuracy of wheel speed measurement failing to meet user needs. Summary of the Invention

[0004] In order to help improve the accuracy of wheel speed measurement, the present application provides a wireless wheel speed measurement method based on an accelerometer and a magnetic field meter and related equipment.

[0005] In a first aspect, the present application provides a wireless wheel speedometer speed measurement method based on an accelerometer and a magnetic field meter, which adopts the following technical solutions: A wireless wheel speedometer speed measurement method based on an accelerometer and a magnetic field meter, comprising: Obtaining a target distance between the accelerometer and the center of the vehicle shaft and a rotational speed of the vehicle shaft; acquiring a target acceleration based on the target distance and the rotational speed; acquiring accelerometer data based on the target acceleration; Based on the accelerometer data, obtaining a first angle corresponding to the accelerometer; Get the magnetic field meter data; Based on the magnetic field meter data, obtaining a second angle corresponding to the magnetic field meter; Acquire a target angle based on the first angle and the second angle; Based on the target angle, obtaining a target angular velocity; The target angular velocity is output.

[0006] By adopting the above technical solution, the target acceleration is first calculated, and then the accelerometer data is calculated based on the target acceleration, and then the first angle is obtained based on the accelerometer data; then the second angle is obtained based on the magnetic field meter data, and then the target angle is calculated by combining the first angle and the second angle, and finally the target angular velocity is calculated and output based on the target angle; by combining the first angle corresponding to the accelerometer and the second angle corresponding to the magnetic field meter, it helps to reduce the influence of external electromagnetic interference on the measurement accuracy, thereby helping to improve the accuracy of wheel speed measurement.

[0007] Optionally, acquiring accelerometer data based on the target acceleration includes: Based on the target acceleration, obtaining a first acceleration component and a second acceleration component; Obtaining a first angle between the accelerometer and the ground; Acquire accelerometer data based on the first acceleration component, the second acceleration component, and the first angle; The accelerometer data satisfies calculation formulas (1) and (2): Among them, B A It is a variable, which is the proportional change caused by the angle between the ground and the horizontal plane; the value of gravity acceleration G is a constant; It's an accelerometer Angle between the axis and the ground; and They are the centrifugal acceleration values sensed by the accelerometer on the X-axis and Y-axis respectively.

[0008] Optionally, acquiring the first acceleration component and the second acceleration component based on the target acceleration includes: Get the unit rotation period; Obtaining a maximum acceleration and a minimum acceleration based on the unit rotation period and the target acceleration; Based on the maximum acceleration, respectively obtaining a first maximum acceleration component and a second maximum acceleration component; Based on the minimum acceleration, respectively obtaining a first minimum acceleration component and a second minimum acceleration component; Obtaining a first acceleration component and a second acceleration component based on the first maximum acceleration component, the first minimum acceleration component, the first minimum acceleration component, and the first minimum acceleration component; The first acceleration component and the second acceleration component satisfy calculation formulas (3) and (4): in, is the first acceleration component, is the first maximum acceleration component, is the first minimum acceleration component, is the second acceleration component, is the second largest acceleration component, is the second smallest acceleration component.

[0009] Optionally, acquiring a first angle corresponding to the accelerometer based on the accelerometer data includes: Obtaining a first sine value and a second sine value based on the accelerometer data and the first acceleration component and the second acceleration component; Calculating the first angle based on the first sine value, the second sine value, and a preset first calculation function; The first angle satisfies the calculation formula (5): in, is the first angle, is the first sine value, is the second sine value, and Atan2(y, x) is the preset first calculation function.

[0010] Optionally, acquiring a target angle based on the first angle and the second angle includes: Get tire information and vehicle speed; Obtaining a target wheel speed based on the tire information and the vehicle speed; Based on the target wheel speed, respectively obtaining an accelerometer wheel speed ratio and a magnetic field meter wheel speed ratio; A target angle is acquired based on the first angle, the second angle, the accelerometer wheel speed ratio, and the magnetometer wheel speed ratio.

[0011] Optionally, the acquiring, based on the target wheel speed, a proportion of the accelerometer wheel speed and a proportion of the magnetic field meter wheel speed respectively includes: Acquiring surrounding environment information, and acquiring magnetic field strength based on the surrounding environment information; Based on the magnetic field strength, determining whether the target area is a strong magnetic area; If the target area is not the strong magnetic area, obtaining the accelerometer wheel speed ratio and the magnetometer wheel speed ratio based on the target wheel speed and a preset comparison relationship; If the target area is the strong magnetic area, obtaining an intensity difference based on the magnetic field intensity and a preset magnetic field threshold; generating a proportional attenuation factor based on the intensity difference; Based on the target wheel speed, the preset comparison relationship, and the proportion attenuation factor, the accelerometer wheel speed proportion and the magnetometer wheel speed proportion are obtained.

[0012] Optionally, acquiring a target angular velocity based on the target angle includes: Based on the unit rotation period, the maximum encoding value is obtained; Obtaining a first coding value and a second coding value based on the maximum coding value, the target angle, and a preset second calculation function; acquiring the target angular velocity based on the maximum code value, the first code value, and the second code value; The target angular velocity satisfies the calculation formula (6): in, is the target angular velocity, E2 is the second code value, E1 is the first code value, t2 is the acquisition time of the second code value, t1 is the acquisition time of the first code value, It is the maximum encoding value within a unit rotation period.

[0013] In a second aspect, the present application also discloses a wireless wheel speedometer speed measurement system based on an accelerometer and a magnetic field meter, which adopts the following technical solution: A wireless wheel speed meter speed measurement system based on an accelerometer and a magnetic field meter, comprising: a first acquisition module, configured to acquire a target distance between the accelerometer and the center of the vehicle shaft and a rotational speed of the vehicle shaft; a second acquisition module, configured to acquire a target acceleration based on the target distance and the rotational speed; a third acquisition module, configured to acquire accelerometer data based on the target acceleration; a fourth acquisition module, configured to acquire a first angle corresponding to the accelerometer based on the accelerometer data; A fifth acquisition module, configured to acquire magnetic field meter data; a sixth acquisition module, configured to acquire a second angle corresponding to the magnetic field meter based on the magnetic field meter data; a seventh acquisition module, configured to acquire a target angle based on the first angle and the second angle; an eighth acquisition module, configured to acquire a target angular velocity based on the target angle; An output module is used to output the target angular velocity.

[0014] By adopting the above technical solution, the target acceleration is first calculated, and then the accelerometer data is calculated based on the target acceleration, and then the first angle is obtained based on the accelerometer data; then the second angle is obtained based on the magnetic field meter data, and then the target angle is calculated by combining the first angle and the second angle, and finally the target angular velocity is calculated and output based on the target angle; by combining the first angle corresponding to the accelerometer and the second angle corresponding to the magnetic field meter, it helps to reduce the influence of external electromagnetic interference on the measurement accuracy, thereby helping to improve the accuracy of wheel speed measurement.

[0015] In a third aspect, the present application provides a computer device that adopts the following technical solution: An intelligent terminal comprises a memory and a processor, wherein the memory is used to store a computer program that can be run on the processor, and when the processor loads the computer program, the method of the first aspect is executed.

[0016] By adopting the above technical solution, a computer program is generated based on the method of the first aspect and stored in a memory to be loaded and executed by a processor, thereby making an intelligent terminal based on the memory and the processor, which is convenient for users to use.

[0017] In a fourth aspect, the present application provides a computer-readable storage medium, which adopts the following technical solution: A computer-readable storage medium stores a computer program, and when the computer program is loaded by a processor, the method of the first aspect is executed.

[0018] By adopting the above technical solution, a computer program is generated based on the method of the first aspect and stored in a computer-readable storage medium so as to be loaded and executed by a processor. The computer-readable storage medium facilitates the readability and storage of the computer program.

[0019] In summary, this application has the following beneficial technical effects: First, the target acceleration is calculated, and then the accelerometer data is calculated based on the target acceleration, and then the first angle is obtained based on the accelerometer data; then the second angle is obtained based on the magnetic field meter data, and then the target angle is calculated by combining the first angle and the second angle. Finally, the target angular velocity is calculated and output based on the target angle; by combining the first angle corresponding to the accelerometer and the second angle corresponding to the magnetic field meter, it helps to reduce the influence of external electromagnetic interference on the measurement accuracy, thereby helping to improve the accuracy of wheel speed measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a main flow chart of a method for measuring speed using a wireless wheel speedometer based on an accelerometer and a magnetic field meter according to an embodiment of the present application; Figure 2 is a flowchart of steps S201 to S203; Figure 3 is a flowchart of steps S301 to S305; Figure 4 is a flowchart of steps S401 to S402; Figure 5 is a flowchart of steps S501 to S504; Figure 6 is a flowchart of steps S601 to S606; Figure 7 is a flowchart of steps S701 to S703; Figure 8 This is a module diagram of a wireless wheel speedometer speed measurement system based on an accelerometer and a magnetic field meter in an embodiment of the present application.

[0021] Description of reference numerals: 1. First acquisition module; 2. Second acquisition module; 3. Third acquisition module; 4. Fourth acquisition module; 5. Fifth acquisition module; 6. Sixth acquisition module; 7. Seventh acquisition module; 8. Eighth acquisition module; 9. Output module. DETAILED DESCRIPTION

[0022] In a first aspect, the present application discloses a speed measurement method of a wireless wheel speedometer based on an accelerometer and a magnetic field meter.

[0023] Reference Figure 1 A wireless wheel speedometer speed measurement method based on an accelerometer and a magnetic field meter includes steps S101 to S109: Step S101: obtaining a target distance between the accelerometer and the center of the vehicle shaft and a rotation speed of the vehicle shaft.

[0024] Specifically, due to the deviation between the accelerometer axis and the center of the vehicle shaft, there is a rotation radius, which is the target distance and is represented by r, and the rotation speed is represented by v.

[0025] Step S102: Obtain target acceleration based on target distance and rotation speed.

[0026] Specifically, when the wheel rotates, centrifugal acceleration is generated and acts on the accelerometer axis. This centrifugal acceleration is the target acceleration. In this embodiment, .

[0027] Step S103: Acquire accelerometer data based on the target acceleration.

[0028] Specifically, in this embodiment, the accelerometer data is the output data of the X-axis and Y-axis of the accelerometer, and X is used to represent the accelerometer data. A and Y A express.

[0029] Step S104: Based on the accelerometer data, a first angle corresponding to the accelerometer is obtained.

[0030] Specifically, in this embodiment, the first angle is the angle measured by the accelerometer.

[0031] Step S105: Obtaining magnetic field meter data.

[0032] Specifically, in this embodiment, the magnetic field meter data refers to the output data of the magnetic field meter on the X-axis and the Y-axis.

[0033] Step S106: Based on the magnetic field meter data, obtain a second angle corresponding to the magnetic field meter.

[0034] Specifically, in this embodiment, the second angle is the angle measured by the magnetic field meter.

[0035] Step S107: Acquire a target angle based on the first angle and the second angle.

[0036] Specifically, in this embodiment, the target angle is a final angle obtained by combining the first angle and the second angle, that is, an angle obtained by simultaneously measuring the accelerometer and the magnetic field meter.

[0037] Step S108: Based on the target angle, obtain the target angular velocity.

[0038] Specifically, in this embodiment, the target angular velocity is the final angular velocity obtained.

[0039] Step S109: Output the target angular velocity.

[0040] In this embodiment, the three axes X of the accelerometer A 、Y A and Z A Orthogonal, magnetic field three axes X M 、Y M and Z M Orthogonal. X A 、Y A , Z A With X M 、Y M , Z M Corresponding parallel. Accelerometer and magnetic field meter Z axis (including Z A and Z M ) is parallel to the wheel rotation axis, X, Y (including X A 、Y A and X M 、YM ) The plane formed by the axes is perpendicular to the ground. Note: There is a small angle between the wheel axis and the ground. This angle is ignored here and the wheel axis is assumed to be parallel to the ground.

[0041] The wireless wheel speedometer speed measurement method based on an accelerometer and a magnetic field meter provided in this embodiment first calculates the target acceleration, then calculates accelerometer data based on the target acceleration, and then obtains a first angle based on the accelerometer data; then obtains a second angle based on the magnetic field meter data, and then combines the first angle and the second angle to calculate the target angle; finally, calculates and outputs the target angular velocity based on the target angle; by combining the first angle corresponding to the accelerometer and the second angle corresponding to the magnetic field meter, it helps to reduce the influence of external electromagnetic interference on the measurement accuracy, thereby helping to improve the accuracy of wheel speed measurement.

[0042] Reference Figure 2 In one implementation of this embodiment, step S103 acquires accelerometer data based on the target acceleration and includes steps S201 to S203: Step S201: Based on the target acceleration, obtain a first acceleration component and a second acceleration component.

[0043] Specifically, in this embodiment, the first acceleration component is the component of acceleration on the X axis, and the second acceleration component is the component of acceleration on the Y axis, respectively. and express.

[0044] Step S202: Acquire a first angle between the accelerometer and the ground.

[0045] Specifically, in this embodiment, the first angle is the accelerometer The angle between the axis and the ground is expressed as express.

[0046] Step S203: Acquire accelerometer data based on the first acceleration component, the second acceleration component, and the first angle.

[0047] Specifically, in this embodiment, the accelerometer data satisfies calculation formulas (1) and (2): Among them, B A It is a variable that changes with the angle between the Z axis corresponding to the accelerometer and the horizontal plane; the gravitational acceleration value G is a constant; It's an accelerometer The angle between the axis and the ground, The angles differ by 90°; and They are the centrifugal acceleration values sensed by the accelerometer on the X-axis and Y-axis respectively.

[0048] Due to the change in the angle between the ground and the horizontal plane (usually the angle between the ground and the horizontal plane of the road where the car is traveling is less than 45 degrees), the sine and cosine curves of the vehicle are The amplitude (peak-to-peak value) varies.

[0049] Reference Figure 3 In one implementation of this embodiment, step S201: obtaining the first acceleration component and the second acceleration component based on the target acceleration includes steps S301 to S305: Step S301: Obtain the unit rotation period.

[0050] Specifically, in this embodiment, a unit rotation period is one wheel rotation period.

[0051] Step S302: Based on the unit rotation period and the target acceleration, obtain the maximum acceleration and the minimum acceleration.

[0052] Specifically, the maximum acceleration and the minimum acceleration are the maximum acceleration and the minimum acceleration corresponding to one wheel rotation cycle.

[0053] Step S303: Based on the maximum acceleration, respectively obtain a first maximum acceleration component and a second maximum acceleration component.

[0054] Specifically, in this embodiment, the first maximum acceleration component is the component of the maximum acceleration on the X-axis, and the second maximum acceleration component is the component of the maximum acceleration on the Y-axis.

[0055] Step S304: Based on the minimum acceleration, respectively obtain a first minimum acceleration component and a second minimum acceleration component.

[0056] Specifically, in this embodiment, the first minimum acceleration component is the component of the minimum acceleration on the X-axis, and the second minimum acceleration component is the component of the minimum acceleration on the Y-axis.

[0057] Step S305: acquiring a first acceleration component and a second acceleration component based on the first maximum acceleration component, the first minimum acceleration component, the first minimum acceleration component and the first minimum acceleration component.

[0058] Specifically, in this embodiment, the first acceleration component and the second acceleration component satisfy calculation formulas (3) and (4): in, is the first acceleration component, is the first maximum acceleration component, is the first minimum acceleration component, is the second acceleration component, is the second largest acceleration component, is the second smallest acceleration component.

[0059] Reference Figure 4 In one implementation of this embodiment, step S104 of obtaining the first angle corresponding to the accelerometer based on the accelerometer data includes steps S401 to S402: Step S401: obtaining a first sine value and a second sine value based on accelerometer data and a first acceleration component and a second acceleration component.

[0060] Specifically, in this embodiment, the first sine value is obtained by deformation of calculation formula (1), and the second sine value is obtained by deformation of calculation formula (2). The first sine value and the second sine value satisfy calculation formulas (7) and (8). .

[0061] Step S402: Calculate a first angle based on the first sine value, the second sine value, and a preset first calculation function.

[0062] Specifically, in this embodiment, the first calculation function is preset, namely the Atan2 function, which is used to calculate the arc tangent value of a given horizontal and vertical coordinate point, that is, according to the given Axis value, returns the arc tangent angle value, the angle range is between -pi (-180°) and +pi (180°); because the data obtained from two axes is used to calculate The accuracy is higher than that of using data from one axis to calculate Therefore, in this embodiment, two axes are used to obtain data. ; The first angle satisfies the calculation formula (5): in, is the first angle, is the first sine value, is the second sine value, and Atan2(y, x) is the preset first calculation function.

[0063] Reference Figure 5 In one implementation of this embodiment, step S107 acquires the target angle based on the first angle and the second angle, including steps S501 to S504: Step S501: Obtain tire information and vehicle speed.

[0064] Specifically, in this embodiment, the tire information includes tire specifications, such as tire cross-section, tire aspect ratio, tire hub diameter, etc., and the vehicle speed is the speed at which the vehicle is running.

[0065] Step S502: Obtain target wheel speed based on tire information and vehicle speed.

[0066] Specifically, the target wheel speed is the number of tire rotations per unit time. In this embodiment, the target wheel speed is the number of tire rotations per second. Taking a tire with a specification of 205 / 55R16 as an example, 205 indicates a cross-sectional width of 205 mm, 55 indicates a 55% aspect ratio, R represents the radial tire construction symbol, and 16 indicates a 16-inch wheel hub diameter. The circumference of a 16-inch wheel is: 16 * 2.54 * 3.14 = 127.61 cm = 1.2761 m. Therefore, at a car speed of 100 km / h, the number of tire rotations per second is: 100 * 1000 / 3600 / 1.2761 = 21.8 rotations. The fastest compass output speed currently is 100 times / second, and the accelerometer output speed is 100 times / second. Therefore, approximately 5 sampling points per second correspond to a cycle from 0° to 360°.

[0067] Step S503: Based on the target wheel speed, respectively obtain the accelerometer wheel speed ratio and the magnetometer wheel speed ratio.

[0068] Specifically, in this embodiment, the accelerometer wheel speed ratio is the weight of the accelerometer wheel speed, and the magnetometer wheel speed ratio is the weight of the magnetometer wheel speed.

[0069] Step S504: obtaining a target angle based on the first angle, the second angle, the accelerometer wheel speed ratio, and the magnetometer wheel speed ratio.

[0070] In this embodiment, a complementary filter can be established to fuse the first angle and the second angle. Specifically, the target angle can be calculated as follows: , where W A and W M are the weights corresponding to the first angle and the second angle respectively.

[0071] It is worth noting that, unlike the accelerometer, when calculating the magnetic field meter data, there is no need to combine the target acceleration. The magnetic field meter data satisfies the calculation formulas (9) and (10): Among them B M is a variable, which is the proportional change caused by the angle between the ground and the horizontal plane; M V The component of the magnetic field perpendicular to the horizontal plane is constant; It is the angle between the X-axis of the magnetic field meter and the ground. The X and Y angles differ by 90°. Since the magnetic field axis is not affected by centrifugal acceleration, there is no symmetry error.

[0072] Similarly, after transforming the calculation formulas (9) and (10), we can obtain the calculation formulas (11) and (12): After using the preset first calculation function, the second angle is calculated, and the second angle satisfies the calculation formula (13): In a certain area, the gravity field is perpendicular to the horizontal plane and is a constant. The component of the geomagnetic field perpendicular to the horizontal plane can also be regarded as a constant. When the wheel rotates, the accelerometer and the magnetic field meter The shaft rotates around the wheel axis and is affected by the vertical component of the gravitational field and the earth's magnetic field. Axis orthogonal, The output data satisfies the sine and cosine functions with a phase difference of 90°.

[0073] Reference Figure 6 In one implementation of this embodiment, step S504 obtains the accelerometer wheel speed ratio and the magnetic field meter wheel speed ratio based on the target wheel speed, including steps S601 to S606: Step S601: Acquire surrounding environment information, and acquire magnetic field strength based on the surrounding environment information.

[0074] Specifically, in this embodiment, the surrounding environment information refers to the environmental information around the area where the vehicle is located, and the magnetic field strength refers to the magnetic field strength around the area where the vehicle is located.

[0075] Step S602: Based on the magnetic field strength, determine whether the target area is a strong magnetic area.

[0076] Specifically, the strong magnetic region is a region with a relatively high magnetic field strength. In this embodiment, a region with a magnetic field strength greater than 0.1 T can be regarded as the strong magnetic region.

[0077] Step S603: If the target area is not a strong magnetic area, the accelerometer wheel speed ratio and the magnetometer wheel speed ratio are obtained based on the target wheel speed and a preset comparison relationship.

[0078] Specifically, in this embodiment, the preset comparison relationship is a pre-set comparison standard used to characterize the corresponding relationship between the target wheel speed and the accelerometer wheel speed ratio and the magnetometer wheel speed ratio.

[0079] Step S604: If the target area is a strong magnetic area, an intensity difference is obtained based on the magnetic field intensity and a preset magnetic field threshold.

[0080] Specifically, the preset magnetic field threshold is a pre-set calibration standard for calibrating a strong magnetic area. In this embodiment, the preset magnetic field threshold can be set to 0.1 T; the intensity difference is the difference obtained by subtracting the preset magnetic field threshold from the magnetic field intensity.

[0081] Step S605: Generate a proportional attenuation factor based on the intensity difference.

[0082] Specifically, in this embodiment, the proportion attenuation factor is an attenuation factor that changes according to the magnitude of the intensity difference. The greater the intensity difference, the greater the proportion attenuation factor.

[0083] Step S606: Based on the target wheel speed, the preset comparison relationship, and the proportion attenuation factor, the accelerometer wheel speed proportion and the magnetometer wheel speed proportion are obtained.

[0084] Reference Figure 7 In one implementation of this embodiment, step S108 obtains the target angular velocity based on the target angle, including steps S701 to S703: Step S701: Based on the unit rotation period, obtain the maximum code value.

[0085] Specifically, in this embodiment, the calculated target angle needs to be converted into a coding output, and the maximum coding value, that is, the maximum coding value of the virtual electronic encoder during one rotation cycle, can be set to 10,000.

[0086] Step S702: Obtain a first coding value and a second coding value based on the maximum coding value, the target angle, and a preset second calculation function.

[0087] Specifically, in this embodiment, the first coding value and the second coding value satisfy the following calculation formula: in, The second calculation function is preset to convert the ±180° angle to 0° to 360° and determine whether the rotation direction is clockwise or counterclockwise. is the target angle, It is the maximum encoding value within a unit rotation period.

[0088] When the wheel rotates clockwise, the angle range increases from 0° to 360°, that is, , when 、 When located at both ends of 360°, ,at this time The symbol is +.

[0089] When the wheel rotates counterclockwise, the angle range decreases from 360° to 0°, that is, , when 、 When located at both ends of 360°, ,at this time The symbol is -.

[0090] The wheels are stationary.

[0091] When the wheel speedometer is installed on the right wheel of the vehicle, clockwise rotation of the wheel corresponds to forward movement of the vehicle.

[0092] Step S703: Obtain a target angular velocity based on the maximum code value, the first code value, and the second code value.

[0093] Specifically, in this embodiment, the target angular velocity satisfies calculation formula (6): in, is the target angular velocity, E2 is the second code value, E1 is the first code value, t2 is the acquisition time of the second code value, t1 is the acquisition time of the first code value, It is the maximum encoding value within a unit rotation period.

[0094] In a second aspect, the present application also discloses a wireless wheel speed measurement system based on an accelerometer and a magnetic field meter.

[0095] Reference Figure 8 A wireless wheel speed meter speed measurement system based on an accelerometer and a magnetic field meter comprises: a first acquisition module, configured to acquire a target distance between the accelerometer and the center of the vehicle shaft and a rotational speed of the vehicle shaft; A second acquisition module is used to acquire target acceleration based on target distance and rotation speed; a third acquisition module, configured to acquire accelerometer data based on target acceleration; a fourth acquisition module, configured to acquire a first angle corresponding to the accelerometer based on the accelerometer data; A fifth acquisition module, configured to acquire magnetic field meter data; a sixth acquisition module, configured to acquire a second angle corresponding to the magnetic field meter based on the magnetic field meter data; a seventh acquisition module, configured to acquire a target angle based on the first angle and the second angle; an eighth acquisition module, configured to acquire a target angular velocity based on the target angle; Output module, used to output target angular velocity.

[0096] In a third aspect, an embodiment of the present application discloses an intelligent terminal comprising a memory and a processor, wherein the memory is used to store a computer program that can be run on the processor. When the processor loads the computer program, it executes a wireless wheel speed measurement method based on an accelerometer and a magnetic field meter according to the above embodiment.

[0097] In a fourth aspect, an embodiment of the present application discloses a computer-readable storage medium, and a computer program is stored in the computer-readable storage medium, wherein when the computer program is loaded by a processor, a wireless wheel speed meter speed measurement method based on an accelerometer and a magnetic field meter of the above embodiment is executed.

[0098] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A wireless wheel speedometer speed measurement method based on an accelerometer and a magnetic field meter, characterized in that: include: Obtaining a target distance between the accelerometer and the center of the vehicle shaft and a rotational speed of the vehicle shaft; acquiring a target acceleration based on the target distance and the rotational speed; acquiring accelerometer data based on the target acceleration; Based on the accelerometer data, obtaining a first angle corresponding to the accelerometer; Get the magnetic field meter data; Based on the magnetic field meter data, obtaining a second angle corresponding to the magnetic field meter; Acquire a target angle based on the first angle and the second angle; Based on the target angle, obtaining a target angular velocity; The target angular velocity is output.

2. The method for measuring speed using a wireless wheel speedometer based on an accelerometer and a magnetic field meter according to claim 1, wherein: The acquiring accelerometer data based on the target acceleration includes: Based on the target acceleration, obtaining a first acceleration component and a second acceleration component; Obtaining a first angle between the accelerometer and the ground; Acquire accelerometer data based on the first acceleration component, the second acceleration component, and the first angle; The accelerometer data satisfies calculation formulas (1) and (2): Among them, B A It is a variable that changes with the angle between the Z axis corresponding to the accelerometer and the horizontal plane; the gravitational acceleration value G is a constant; It's an accelerometer Angle between the axis and the ground; and They are the centrifugal acceleration values sensed by the accelerometer on the X-axis and Y-axis respectively.

3. The method for measuring speed using a wireless wheel speedometer based on an accelerometer and a magnetic field meter according to claim 2, wherein: The acquiring the first acceleration component and the second acceleration component based on the target acceleration includes: Get the unit rotation period; Obtaining a maximum acceleration and a minimum acceleration based on the unit rotation period and the target acceleration; Based on the maximum acceleration, respectively obtaining a first maximum acceleration component and a second maximum acceleration component; Based on the minimum acceleration, respectively obtaining a first minimum acceleration component and a second minimum acceleration component; Obtaining a first acceleration component and a second acceleration component based on the first maximum acceleration component, the first minimum acceleration component, the first minimum acceleration component, and the first minimum acceleration component; The first acceleration component and the second acceleration component satisfy calculation formulas (3) and (4): in, is the first acceleration component, is the first maximum acceleration component, is the first minimum acceleration component, is the second acceleration component, is the second largest acceleration component, is the second smallest acceleration component.

4. The method for measuring speed using a wireless wheel speedometer based on an accelerometer and a magnetic field meter according to claim 1, wherein: The acquiring, based on the accelerometer data, a first angle corresponding to the accelerometer includes: Obtaining a first sine value and a second sine value based on the accelerometer data and the first acceleration component and the second acceleration component; Calculating the first angle based on the first sine value, the second sine value, and a preset first calculation function; The first angle satisfies the calculation formula (5): in, is the first angle, is the first sine value, is the second sine value, and Atan2(y, x) is the preset first calculation function.

5. The method for measuring speed using a wireless wheel speedometer based on an accelerometer and a magnetic field meter according to claim 1, wherein: The acquiring a target angle based on the first angle and the second angle includes: Get tire information and vehicle speed; Obtaining a target wheel speed based on the tire information and the vehicle speed; Based on the target wheel speed, respectively obtaining an accelerometer wheel speed ratio and a magnetic field meter wheel speed ratio; A target angle is acquired based on the first angle, the second angle, the accelerometer wheel speed ratio, and the magnetometer wheel speed ratio.

6. The method for measuring speed using a wireless wheel speedometer based on an accelerometer and a magnetic field meter according to claim 5, wherein: The obtaining of the accelerometer wheel speed ratio and the magnetic field meter wheel speed ratio based on the target wheel speed includes: Acquiring surrounding environment information, and acquiring magnetic field strength based on the surrounding environment information; Based on the magnetic field strength, determining whether the target area is a strong magnetic area; If the target area is not the strong magnetic area, obtaining the accelerometer wheel speed ratio and the magnetometer wheel speed ratio based on the target wheel speed and a preset comparison relationship; If the target area is the strong magnetic area, obtaining an intensity difference based on the magnetic field intensity and a preset magnetic field threshold; generating a proportional attenuation factor based on the intensity difference; Based on the target wheel speed, the preset comparison relationship, and the proportion attenuation factor, the accelerometer wheel speed proportion and the magnetometer wheel speed proportion are obtained.

7. The method for measuring speed using a wireless wheel speedometer based on an accelerometer and a magnetic field meter according to claim 1, wherein: The acquiring the target angular velocity based on the target angle includes: Based on the unit rotation period, the maximum encoding value is obtained; Obtaining a first coding value and a second coding value based on the maximum coding value, the target angle, and a preset second calculation function; acquiring the target angular velocity based on the maximum code value, the first code value, and the second code value; The target angular velocity satisfies the calculation formula (6): in, is the target angular velocity, E2 is the second code value, E1 is the first code value, t2 is the acquisition time of the second code value, t1 is the acquisition time of the first code value, It is the maximum encoding value within a unit rotation period.

8. A wireless wheel speedometer speed measurement system based on an accelerometer and a magnetic field meter, characterized in that: include: a first acquisition module, configured to acquire a target distance between the accelerometer and the center of the vehicle shaft and a rotational speed of the vehicle shaft; a second acquisition module, configured to acquire a target acceleration based on the target distance and the rotational speed; a third acquisition module, configured to acquire accelerometer data based on the target acceleration; a fourth acquisition module, configured to acquire a first angle corresponding to the accelerometer based on the accelerometer data; A fifth acquisition module, configured to acquire magnetic field meter data; a sixth acquisition module, configured to acquire a second angle corresponding to the magnetic field meter based on the magnetic field meter data; a seventh acquisition module, configured to acquire a target angle based on the first angle and the second angle; an eighth acquisition module, configured to acquire a target angular velocity based on the target angle; An output module is used to output the target angular velocity.

9. An intelligent terminal, comprising a memory and a processor, characterized in that: The memory is used to store a computer program that can be run on the processor, and when the processor loads the computer program, it executes the method according to any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, wherein: When the computer program is loaded into a processor, the method according to any one of claims 1 to 7 is executed.

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