Method and apparatus for determining rotational frequency of a wheel of a vehicle

Abstract

A device (2) for determining a rotational frequency of at least one wheel of a vehicle, comprising a first measuring component (5) for measuring acceleration values of the at least one wheel, a second measuring component (6) for measuring vibrations of the at least one wheel, and a processing unit (4) configured to determine a first rotational frequency of the at least one wheel from the measured acceleration values of the at least one wheel, to compare the determined first rotational frequency of the at least one wheel with a first threshold value, to define a frequency analysis interval from the determined first rotational frequency being greater than the first threshold value, to process a frequency analysis of a signal indicative of the vibrations of the at least one wheel for frequencies within the frequency analysis interval, and to select a second rotational frequency having a higher amplitude in the frequency analysis interval, the second rotational frequency being equal to the rotational frequency of the at least one wheel.

Description

Technical Field

[0001] This invention relates to the determination of the rotational frequency of wheels, and more particularly to an apparatus and method for determining the rotational frequency of wheels of a vehicle. Background Technology

[0002] In vehicles (such as trucks, buses, or trailers), it is often necessary to monitor several components in order to detect damage or wear.

[0003] One of these components could be, for example, a wheel used in a truck. In such a wheel, the bearing supporting the wheel can be equipped with a sensor that can be used to detect a failure in the bearing.

[0004] To miniaturize the sensor and reduce its cost, the sensor is configured to perform two functions: determine the rotational speed of the wheel and determine the vibration of the wheel.

[0005] Document US2019 / 0329610 discloses a sensor that includes a piezoelectric element for measuring the vibration of a wheel and a determination unit for determining the rotational speed and vibration of the wheel using signals from a single sensor.

[0006] The determination unit performs frequency analysis on the signals from a single sensor to determine the rotational speed of the wheel.

[0007] However, the determination of rotational speed is not reliable enough. It has been observed that on some vehicles, the determined rotational speed is twice the actual rotational speed of the wheels.

[0008] An accelerometer can be used to determine the rotational speed of a wheel.

[0009] However, the determined speed is insufficient to accurately perform frequency analysis on the signal transmitted by the accelerometer to determine the vibration generated by the wheel. Summary of the Invention

[0010] It is necessary to avoid at least some of the previously mentioned drawbacks, especially by more accurately determining the wheel's rotational speed to perform reliable vibration analysis, thereby detecting wheel bearing damage.

[0011] According to one aspect, a method for determining the rotational frequency of at least one wheel of a vehicle.

[0012] The method includes:

[0013] The first rotational frequency of the at least one wheel is determined from the acceleration value of the at least one wheel.

[0014] The first rotational frequency of the at least one wheel is determined and compared with a first predetermined threshold.

[0015] The frequency analysis interval is defined based on the first rotation frequency being greater than the first threshold.

[0016] Frequency analysis is performed on the signal indicating the vibration of at least one wheel within the frequency analysis interval, and...

[0017] Select a second rotational frequency with the higher amplitude within the frequency analysis interval, the second rotational frequency being equal to the rotational frequency of the at least one wheel.

[0018] Advantageously, defining the frequency analysis interval includes defining a lower bound and an upper bound of the frequency analysis interval, the lower bound being equal to a determined first rotation frequency minus a second predetermined threshold, and the upper bound being equal to a determined first rotation frequency plus the second threshold.

[0019] Preferably, the frequency analysis process includes implementing the Goertzel algorithm.

[0020] Preferably, determining the first rotational frequency includes determining a first distance equal to the distance between the center of the at least one wheel and the first component used to measure the acceleration value, and calculating the first rotational frequency as equal to...

[0021] On the other hand, an apparatus for determining the rotational frequency of at least one wheel of a vehicle has been proposed.

[0022] The device includes:

[0023] A first measuring component is used to measure the acceleration value of the at least one wheel.

[0024] A second measuring component is used to measure the vibration of the at least one wheel, and

[0025] The processing unit is configured as follows:

[0026] • Determine the first rotational frequency of the at least one wheel from the measured acceleration value of the at least one wheel.

[0027] • The determined first rotational frequency of the at least one wheel is compared with a first threshold.

[0028] • Define the frequency analysis interval based on the first rotation frequency being greater than the first threshold.

[0029] • Processing the frequency analysis of the signal indicating the vibration of at least one wheel within the frequency analysis interval, and

[0030] • Select a second rotational frequency with a higher amplitude within the frequency analysis interval, wherein the second rotational frequency is equal to the rotational frequency of the at least one wheel.

[0031] Preferably, the processing unit is configured to define a lower bound and an upper bound of the frequency analysis interval, wherein the lower bound is equal to the determined first rotation frequency minus a second threshold, and the upper bound is equal to the determined first rotation frequency plus the second threshold.

[0032] Advantageously, the device also includes an energy storage component for supplying power to the processing unit.

[0033] Preferably, the processing unit is configured to wirelessly transmit the second rotation frequency.

[0034] Advantageously, the processing unit is configured to detect a failure in the bearing supporting the wheel based on the value of the rotational frequency of at least one wheel and a signal indicating the vibration transmitted by the second measuring component.

[0035] On the other hand, a wheel for a vehicle that includes the device defined above has been proposed. Attached Figure Description

[0036] Other advantages and features of the invention will emerge without limitation upon review of the detailed description and drawings of the embodiments, wherein:

[0037] [ Figure 1 An example of a wheel according to the present invention is shown schematically;

[0038] [ Figure 2 An embodiment of a device for determining the rotational frequency of a wheel is schematically shown.

[0039] [ Figure 3 The method for determining the rotational frequency of a wheel is shown, and

[0040] [ Figure 4 An example of frequency analysis according to the present invention is shown. Detailed Implementation

[0041] Reference Figure 1 , which represents an example of wheel 1 of a vehicle.

[0042] The vehicle can be, for example, a truck, a bus, or a trailer.

[0043] A device 2 for determining the rotational frequency of wheel 1 is arranged on wheel 1.

[0044] Device 2 is fastened, for example, to nut 3 of wheel 1, and is a first distance D1 from the center C1 of wheel 1.

[0045] Figure 2 Examples of implementations of device 2 are disclosed.

[0046] The device 2 includes a first measuring component for measuring the acceleration value of the wheel 1, a second measuring component for measuring the vibration of the wheel 1, and a processing unit 4.

[0047] The first measuring component includes, for example, an accelerometer 5 connected to the processing unit 4, and the second measuring component includes, for example, a vibration sensor 6 connected to the processing unit 4.

[0048] Device 2 may also include an energy storage component for supplying power to processing unit 4, the energy storage component may include, for example, a battery 7.

[0049] Device 2 does not require an external power source and is autonomous.

[0050] Figure 3 This describes an implementation of a method for determining the rotational frequency of wheel 1.

[0051] In step 10, accelerometer 5 measures the acceleration value VAL of wheel 1.

[0052] Processing unit 4 calculates the first rotational frequency F1 of wheel 1, and the first rotational frequency F1 is equal to:

[0053]

[0054] Processing unit 4 compares the determined first rotation frequency F1 with the first predetermined threshold TH1.

[0055] If the first rotation frequency F1 is less than the first threshold TH1 (step 11), then wheel 1 is considered to have stopped.

[0056] Then, after the predetermined duration (e.g., after 30 minutes), repeat step 10.

[0057] The first threshold TH1 can be, for example, equal to 4.2 Hz.

[0058] If the first rotation frequency F1 is equal to or greater than the first threshold TH1 (step 11), then wheel 1 is considered to be moving.

[0059] Processing unit 4 defines a frequency analysis interval (frequency analysis interval) INT, which includes a lower bound ( / lower limit) LB and an upper bound ( / upper limit) UB (step 12).

[0060] Processing unit 4 defines a lower bound LB and an upper bound UB, such that...

[0061] LB = F1 - TH2 (2)

[0062] UB=F1+TH2 (3)

[0063] Here, TH2 serves as a second predetermined threshold. The second threshold TH2 can be, for example, equal to 2.5 Hz.

[0064] In step 13, the vibration sensor 6 transmits a signal indicating the vibration of the wheel 1 to the processing unit 4, and the processing unit 4 performs frequency analysis on the signal for the frequency within the frequency analysis interval INT.

[0065] Processing unit 4 implements, for example, the Goertzel algorithm to perform frequency analysis.

[0066] In step 14, the processing unit 4 determines the second rotational frequency F2 of the wheel 1 from the processed frequency analysis.

[0067] Processing unit 4 selects a frequency with a higher amplitude in the frequency analysis interval INT, and the second rotation frequency F2 is equal to the frequency with the higher amplitude.

[0068] The second rotational frequency F2 is equal to the rotational frequency F of wheel 1. wheel .

[0069] Processing unit 4 determines the rotation frequency F of wheel 1. wheel The value and the signal indicating vibration are used to detect the failure of the bearing supporting wheel 1.

[0070] Then, repeat step 10 after the predetermined duration (e.g., after 30 minutes).

[0071] Figure 4 The rotational frequency F of the wheel 1 is disclosed. wheel An example of frequency analysis performed by processing unit 4.

[0072] Processing unit 4 can, for example, process the rotation frequency F of wheel 1. wheel Wirelessly transmit ( / transfer) to another processing unit, for example, for vibration analysis or wheel speed comparison while wheel 1 is moving.

[0073] The rotational frequency of wheel 1 can be reliably determined with an enhanced accuracy of, for example, + / -0.5Hz, making bearing damage detection more reliable.

[0074] Furthermore, using the first measuring component to determine whether wheel 1 is moving consumes less energy than using a vibration sensor to determine the rotational speed of wheel 1.

[0075] It allows for energy savings, thereby extending the operating time of the energy storage components, and thus extending the operating time of device 2.

[0076] In addition, performing frequency analysis on frequencies within the frequency analysis interval INT reduces the computation time of the processing unit UT, thereby saving even more energy to extend the operating time of device 2.

Claims

1. A method for determining the rotational frequency of at least one wheel (1) of a vehicle, the method comprising: - Determine the first rotational frequency (F1) of the at least one wheel (1) from the acceleration value of the at least one wheel. - The determined first rotational frequency (F1) of the at least one wheel is compared with a first predetermined threshold (TH1), wherein the first predetermined threshold (TH1) is 4.2 Hz. - If the determined first rotation frequency (F1) is greater than the first predetermined threshold (TH1), then a frequency analysis interval (INT) is defined based on the determined first rotation frequency (F1). - The frequency analysis of the signal indicating the vibration of at least one wheel (1) within the frequency analysis interval is performed, and - Select a second rotational frequency (F2) with a higher amplitude within the frequency analysis interval, the second rotational frequency being equal to the rotational frequency (F) of the at least one wheel. wheel ).

2. The method according to claim 1, characterized in that, Defining the frequency analysis interval (INT) includes defining the lower bound (LB) and the upper bound (UB) of the frequency analysis interval, wherein the lower bound is equal to the determined first rotation frequency (F1) minus the second predetermined threshold (TH2), and the upper bound is equal to the determined first rotation frequency (F1) plus the second predetermined threshold (TH2).

3. The method according to claim 1 or 2, characterized in that, Processing the frequency analysis includes implementing the Goertzel algorithm.

4. The method according to claim 1 or 2, characterized in that, Determining the first rotational frequency (F1) includes determining a first distance (D1), which is equal to the distance between the center (C1) of the at least one wheel (1) and the first component used to measure the acceleration value, and calculating the first rotational frequency (F1) as equal to... .

5. A device (2) for determining the rotational frequency of at least one wheel (1) of a vehicle, the device comprising: - First measuring component (5), used to measure the acceleration value of at least one wheel, - A second measuring component (6) is used to measure the vibration of the at least one wheel, and - The processing unit (4) is configured as follows: The first rotational frequency (F1) of the at least one wheel is determined from the measured acceleration value of the at least one wheel. The determined first rotational frequency (F1) of the at least one wheel is compared with a first predetermined threshold (TH1), wherein the first predetermined threshold (TH1) is 4.2 Hz. If the determined first rotation frequency (F1) is greater than the first predetermined threshold (TH1), then a frequency analysis interval (INT) is defined based on the determined first rotation frequency (F1). Frequency analysis is performed on the signal indicating the vibration of at least one wheel within the frequency analysis interval, and... Select a second rotational frequency (F2) with a higher amplitude within the frequency analysis interval. This second rotational frequency is equal to the rotational frequency (F) of the at least one wheel. wheel ).

6. The apparatus according to claim 5, characterized in that, The processing unit (4) is configured to define a lower bound (LB) and an upper bound (UB) of the frequency analysis interval, wherein the lower bound is equal to the determined first rotation frequency (F1) minus a second predetermined threshold (TH2), and the upper bound is equal to the determined first rotation frequency (F1) plus the second predetermined threshold (TH2).

7. The apparatus according to claim 5 or 6, characterized in that, It also includes an energy storage component (7) for supplying energy to the processing unit (4).

8. The apparatus according to claim 5 or 6, characterized in that, The processing unit (4) is configured to wirelessly transmit the second rotation frequency (F2).

9. The apparatus according to claim 5 or 6, characterized in that, The processing unit (4) is configured to adjust the rotation frequency (F) of the at least one wheel according to the rotation frequency (F) of the wheel. wheel The value of the signal and the vibration signal transmitted by the second measuring component (6) are used to detect the failure of the bearing supporting the wheel.

10. A wheel (1) of a vehicle, comprising means (2) for determining the rotational frequency of at least one wheel (1) of the vehicle according to any one of claims 5 to 9.

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