Method for attenuating interference in measuring vehicle tilt angles - Patents.com

Abstract

To provide a motorized two-wheeled vehicle capable of preventing engine vibration from artificially exceeding a tilt threshold value during tilt angle measurement. [Solution] A method for attenuating interference in measuring the lateral inclination angle of a motorized two-wheeled vehicle (1) having an electronic control unit (11) configured to calculate the lateral inclination angle of the vehicle from measurements of an inclination sensor (111), the method including a step (E1) of receiving a speed value of the vehicle (1) measured by a speed measurement module (13), a step (E2) of receiving the revolutions per minute of the engine (10), a step (E3) of calculating the ratio between the received speed value and the received revolutions per minute, a step (E4) of comparing the ratio between the received speed value and the revolutions per minute with a damping interval, and a step (E7) of calculating the inclination angle without taking damping into account if the ratio is outside the damping interval, and a step (E8) of calculating the inclination angle taking damping into account if the ratio is within the damping interval.

Description

[Technical Field]

[0001] The present invention relates to the field of motorized two-wheelers, and more particularly to measuring the lateral lean angle of a motorized two-wheeler.

[0002] Background technology In order to improve driver safety, many motorized two-wheelers are now equipped with systems that can act directly on the operation of the vehicle as soon as a critical situation is detected, without driver intervention.

[0003] Motorbike manufacturers are known to include tilt sensors in their vehicles that measure, among other things, the lateral tilt of the vehicle, and are configured to have a maximum tilt threshold above which the vehicle is deemed to be tipping over, thereby shutting down the engine and ensuring driver safety.

[0004] For example, this threshold is 60° relative to the vertical direction defined by the Earth's gravity, and if the actual tilt angle of the vehicle exceeds 60°, the vehicle is determined to be tipping over and the engine is shut down.

[0005] The device also allows the engine to be prevented from starting if the vehicle is tilted beyond this threshold when the user attempts to start the engine.

[0006] First-generation mechanical tilt sensors were mounted on the vehicle chassis. These sensors contained weights (e.g., balls) that moved according to the vehicle's tilt, closing electrical contacts when a predetermined tilt was exceeded. The inertia of these weights therefore determined the sensor's sensitivity to the vehicle's tilt and, therefore, the accuracy of the angle measurement.

[0007] However, these sensors were bulky and had significant limitations regarding their mounting on the vehicle chassis. For these reasons, a new generation of sensors is now being used, consisting of an electronic control unit containing a MEMS accelerometer (MEMS stands for Micro-Electro-Mechanical System). This type of sensor may be mounted directly on the engine, for example on the intake manifold, or indeed in close proximity to the engine.

[0008] However, due to the proximity of the sensor to the engine, vibrations generated by the engine can affect the sensor and cause interference with the measurement of the lean angle. The risk is that this interference could cause the maximum lean threshold to be artificially exceeded for a sufficient period of time that the electronic control unit would interpret this as a rollover and activate the engine shutdown function during normal vehicle operation.

[0009] This problem is further exacerbated by the sampling of the tilt angle measurements. Specifically, interference related to engine operation is periodic. Therefore, if the sampling frequency is set without taking into account the frequency of the interference (in terms of the Nyquist-Shannon sampling theorem), the period of the reconstructed signal may be longer than the period of the engine's mechanical vibrations. This physical phenomenon is called aliasing, and therefore may result in the maximum tilt threshold being artificially exceeded for a long period of time, increasing the risk that the electronic control unit will trigger an engine shutdown.

[0010] One way to mitigate the aliasing problem is to increase the sampling frequency used to measure the tilt angle in order to capture the actual interference period. However, this solution is energy intensive and computationally intensive, potentially saturating the computer's performance and limiting its ability to perform and store more measurements. Furthermore, even without aliasing, engine vibrations cannot prevent the tilt threshold from being artificially exceeded during tilt angle measurement.

[0011] There is therefore a need for a simple and effective solution that makes it possible to at least partially overcome these drawbacks.

[0012] Summary of the Invention To this end, a first aspect of the invention relates to a method for attenuating interference in measurements of lateral tilt angles of a motorized two-wheeled vehicle, said vehicle comprising an engine connected to a mechanical transmission, an electronic control unit and a speed measurement module, said electronic control unit comprising an inclination sensor and a memory area containing at least one pre-determined attenuation interval, said electronic control unit being configured to calculate the lateral tilt angle of the vehicle from measurements of the inclination sensor, to receive speed values ​​of the vehicle measured by the speed measurement module and to receive revolutions per minute of the engine, said method comprising: - receiving by the electronic control unit a speed value of the vehicle measured by a speed measurement module; - an electronic control unit receiving the engine revolutions per minute; - the electronic control unit calculating the ratio between the received speed value and the received revolutions per minute; - the electronic control unit comparing the ratio of the received speed value to the revolutions per minute with at least one damping interval; - if the ratio between the received speed value and the revolutions per minute is outside the damping interval, the electronic control unit calculates the tilt angle without taking damping into account; - if the ratio between the received speed value and the revolutions per minute is within a damping interval, the electronic control unit calculates a tilt angle taking damping into account; Includes:

[0013] The method according to the present invention thus allows for damping the effect of engine vibrations on the determination of the vehicle's lateral tilt angle. If it is determined that these vibrations could interfere with the angle measurement, causing the tilt threshold to be exceeded for a long enough period of time to trigger the vehicle's shutdown function, the electronic control unit damps the tilt sensor measurement components that have the greatest effect on the tilt angle measurement. Thus, while the tilt angle is still representative of the vehicle's physical tilt, vibrations are less likely to cause oscillations in the calculated tilt angle (which could potentially exceed the tilt threshold). If the ratio of the received speed value to the revolutions per minute is within the damping interval, the vehicle speed is consistent with the engine speed, making it unlikely that the vehicle is tipping over. Therefore, the damping method avoids false tipping detection. In contrast, if the ratio of the received speed value to the revolutions per minute is outside this interval, a discrepancy that could indicate a problem occurs, and therefore it is safer not to dampen the signal so that an engine shutdown command can be sent as quickly as possible.

[0014] Preferably, the engine is connected to a mechanical transmission, and the step of receiving the engine revolutions per minute by the electronic control unit is followed by a step of determining the engaged gear ratio of the transmission, which may be determined directly by sending a signal from the transmission to the electronic control unit, or by actually calculating the ratio between the measured speed and the engine revolutions per minute, which may be used to ensure redundancy in verifying the application conditions of the method according to the invention.

[0015] Advantageously, if the electronic control unit receives from the transmission that a gear ratio is not engaged, the electronic control unit does not perform the step of calculating the ratio between the received speed value and the received engaged gear ratio, and calculates the lean angle without considering damping. In this case, engine vibrations are minimal and therefore no damping is required. Measuring the lean angle of the vehicle is important when the engine is running, for example when the vehicle is stationary and about to accelerate.

[0016] In a preferred embodiment, the speed measurement module has a reference speed value in memory that the speed measurement module transmits to the electronic control unit in the event of a speed measurement module failure, so that the method for measuring tilt angles and attenuating the measurements can function even if the speed measurement module fails.

[0017] In one embodiment of the present invention, the tilt sensor is configured to determine a projection value of Earth's gravity onto three axes, and the electronic control unit is configured to calculate a tilt angle from the three projection values ​​determined by the tilt sensor. The memory area includes at least one damping coefficient, and the step of calculating the tilt angle taking damping into account corresponds to the electronic control unit multiplying at least one projection value determined by the tilt sensor by at least one damping coefficient. The damping may be applied to one of the projection values ​​measured by the tilt sensor. Thus, if it is determined that one of the projection values ​​does not affect the calculation of the tilt angle to a first approximation, the electronic control unit does not need to damp this projection value in the calculation. For example, the electronic control unit may perform a self-diagnosis to apply a correction to the projection value. If the correction does not change the calculated tilt angle or only slightly changes it, it may be determined that the projection value does not affect the first approximation.

[0018] Advantageously, in this embodiment, the memory area contains at least three damping coefficients, each corresponding to one projection axis, and the step of calculating the tilt angle taking damping into account corresponds to the electronic control unit multiplying each of the three projection values ​​determined by the tilt sensor by the corresponding damping coefficient, thus allowing damping to be appropriately applied to each of the three projection values ​​measured by the tilt sensor.

[0019] Advantageously, the memory area also contains at least one damping coefficient corresponding to each gear ratio of the vehicle transmission, and the step of calculating the tilt angle taking damping into account corresponds to the electronic control unit multiplying the at least one projection value determined by the tilt sensor by the damping coefficient corresponding to the received gear ratio, so that the electronic control unit applies different damping depending on the engaged gear ratio of the vehicle transmission.

[0020] Preferably, in this embodiment, the memory area contains three damping coefficients, each corresponding to one projection axis, for each gear ratio of the vehicle's transmission, and the step of calculating the tilt angle taking damping into account corresponds to the electronic control unit multiplying each projection value determined by the tilt sensor by the damping coefficient corresponding to the projection axis and the received gear ratio, so that the damping is adjusted to the vehicle's operation.

[0021] According to another aspect, the present invention also relates to an electronic control unit for a motorized two-wheeled vehicle, said electronic control unit comprising an incline sensor and a memory area, said memory area containing at least one damping interval, said electronic control unit being configured to be connected to a speed measurement module and to a mechanical transmission of an engine of said vehicle, said electronic control unit comprising: - receiving a vehicle speed value measured by a speed measurement module; -Receives the engaged gear ratio in the transmission, - calculating the ratio between the received speed value and the received engaged gear ratio; comparing the ratio of the received speed value to the engaged gear ratio with a first threshold; - Calculates the lean angle without taking into account the vehicle's damping, -Calculate the tilt angle taking into account the vehicle's damping It is further structured as follows.

[0022] According to another aspect, the invention also relates to a motorized two-wheeled vehicle comprising an engine connected to a transmission, a speed measurement module and an electronic control unit as described above.

[0023] Further characteristics and advantages of the invention will appear more clearly on reading the following description, which is purely exemplary and should be read with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0024] [Figure 1] 1 shows a schematic representation of a motorized two-wheeled vehicle to which the method according to the invention is applied; [Figure 2] 1 shows a schematic representation of an electronic control unit for implementing the method; [Figure 3] 3 shows a schematic representation of the lateral tilt of the vehicle relative to a tilt threshold that activates the engine shut-off function. [Figure 4] 1 shows a schematic sequence of the method according to the invention;

[0025] MODE FOR CARRYING OUT THE INVENTION The method according to the invention is applicable to a motorized two-wheeled vehicle 1 .

[0026] Car 1 As shown in FIG. 1, a vehicle 1 includes an engine 10, an electronic control unit 11, a mechanical transmission 12, a speed measurement module 13, and a communication link 14. Engine 10

[0027] The engine 10 makes it possible to generate the torque required to drive the wheels of the vehicle 1 when the vehicle is moving. This torque is transmitted by the rotation of a shaft that rotates at a certain number of revolutions per minute, also called the engine speed.

[0028] The engine 10 is connected to a transmission 12 .

[0029] The engine 10 can operate without any of the gears of the mechanical transmission 12 being engaged, for example when starting the vehicle 1 .

[0030] The transmission 12 is used to transmit engine speed to the wheels, and the proportionality factor between engine speed and wheel speed varies depending on the engaged gear ratio.

[0031] Electronic Control Unit 11 As shown in FIG. 2, the electronic control unit 11 includes a tilt sensor 111 and a memory area 112 .

[0032] The tilt sensor 111 is preferably a MEMS accelerometer configured to calculate the projection of the Earth's gravity onto the three axes of a reference coordinate system.

[0033] The electronic control unit 11 is configured to calculate the lateral tilt angle of the vehicle 1 relative to the Earth's vertical (Z axis) from the three projection values ​​measured by the tilt sensor 111 .

[0034] The memory area 112 is configured to store information, in particular, the memory area 112 contains an angle θs corresponding to a tilt threshold beyond which the electronic control unit 11 determines that the vehicle 1 is in the process of tipping over, as shown in Figure 3.

[0035] 3, the Z axis corresponds to the vertical direction of the Earth, and the Y axis corresponds to the horizontal direction perpendicular to the vehicle 1. The tilt angle is the angle between the Y axis and the vehicle 1.

[0036] The memory area 112 also contains at least one decay interval corresponding to the ratio between the speed of the vehicle 1 and the revolutions per minute of the engine 10 .

[0037] This interval corresponds to the value of this ratio under normal conditions of movement of the vehicle 1, in particular when it is not overturned.

[0038] The memory area 112 also contains a plurality of stored attenuation coefficients.

[0039] Preferably, the memory area 112 contains one coefficient for each of the three axes of the reference coordinate system of the tilt sensor 111 and for each gear ratio of the transmission 12 .

[0040] Thus, for example, for a vehicle 1 having a transmission 12 with five gear ratios, the memory area 112 contains 15 coefficients.

[0041] Advantageously, the coefficients stored in memory area 112 are less than or equal to one.

[0042] The attenuation coefficient or coefficients may, in another embodiment, be a low pass filter that does not attenuate low frequencies (where aliasing problems are less pronounced) but does attenuate high frequencies.

[0043] The electronic control unit 11 is configured to calculate a tilt angle taking into account damping by multiplying at least one projection value measured by the tilt sensor 111 by a corresponding coefficient, and to calculate the tilt angle from this value.

[0044] The electronic control unit 11 is configured to compare the calculated tilt angle with a tilt threshold θs.

[0045] The inclination threshold θs corresponds to the angle at which the electronic control unit 11 determines that the vehicle 1 has turned over.

[0046] The electronic control unit 11 is configured to perform a function to shut down the engine 10 of the vehicle 1 if the measured lateral tilt angle is greater than a tilt threshold θs.

[0047] The electronic control unit 11 is configured to receive the revolutions per minute of the engine 10 via a communication link 14 .

[0048] The electronic control unit 11 is configured to receive the engaged gear ratio for the transmission 12 of the engine 10 via a communication link 14 .

[0049] The electronic control unit 11 is also configured to determine the gear ratio engaged in the transmission 12 of the engine 10 from a calculation of the ratio between the speed of the vehicle 1 and the revolutions per minute of the engine 10 .

[0050] The electronic control unit 11 is arranged to receive, via a communication link 14 , speed values ​​of the vehicle 1 measured by a speed measurement module 13 .

[0051] Transmission 12 The transmission 12 has multiple gear ratios that allow the torque produced by the engine 10 to be matched to the performance desired by the user of the vehicle 1.

[0052] The transmission 12 is mechanically connected to the engine 10 as shown in FIG.

[0053] The transmission 12 is configured to send a signal via a communication link 14 to the electronic control unit 11 indicating which gear ratio is engaged, or whether a gear ratio is actually engaged.

[0054] Speed ​​Measurement Module 13 The speed measurement module 13 is configured to measure the speed at which the vehicle 1 is moving.

[0055] The speed measurement module 13 may be of various types, for example a revolution counter mounted on one of the wheels of the vehicle 1 .

[0056] Communication Link 14 A communication link 14 enables communication between the electronic control unit 11 and the engine 10 , the transmission 12 and the speed measurement module 13 .

[0057] Preferably, the communication link 14 is a wired communication link, for example of the CAN type.

[0058] Example of an embodiment When the vehicle 1 is moving, the engine 10 is operating. Vibrations generated by the operation of the engine 10 are transmitted to the electronic control unit 11 and detected by the tilt sensor 111.

[0059] The angle calculated by the electronic control unit 11 from the measurements of the tilt sensor 111 therefore takes these vibrations into account.

[0060] The method according to the invention aims to reduce the influence of vibrations on the calculation of the tilt angle in configurations where the vibrations are too great.

[0061] In a first step E1 of the method, the electronic control unit 11 receives the speed value of the vehicle 1 measured by the speed measurement module 13 .

[0062] In a second step E2, the electronic control unit 11 receives the revolutions per minute of the engine 10 and the gear ratio engaged in the transmission 12. If in this step the electronic control unit 11 receives that no gear ratio is engaged, the method stops.

[0063] Specifically, this particular case indicates that the vehicle 1 is stationary or moving at a very slow speed and is not being driven by the engine 10, and therefore there is no need to mitigate the effects of vibration.

[0064] Steps E1 and E2 may be performed either sequentially or simultaneously.

[0065] In step E3, the electronic control unit 11 calculates the ratio between the speed value received from the speed measurement module 13 and the revolutions per minute of the engine 10.

[0066] In step E 4 , the electronic control unit 11 compares the ratio thus calculated with the decay interval stored in the memory area 112 .

[0067] This interval corresponds to the expected operating point of the vehicle 1 under normal conditions. Under these conditions, the vehicle 1 is unlikely to tilt beyond the tilt angle threshold θs, and therefore it is appropriate to attenuate the signal used to calculate the tilt angle to prevent the electronic control unit 11 from falsely detecting a rollover of the vehicle 1 and thus activating the engine shutdown function.

[0068] If the calculated ratio is outside the damping interval, the operating point of the vehicle 1 may be in a state where there is a risk of rollover. In order to avoid falsely detecting a rollover, the electronic control unit 11 performs step E5 * Then the tilt angle without considering the damping is measured and the damping method is restarted from step E1.

[0069] If the calculated ratio is within the damping interval, the electronic control unit 11 detects that the vehicle 1 is unlikely to roll over.

[0070] In this case, the electronic control unit 11 selects, in step E5, the triplet of damping coefficients corresponding to the on-coming gear ratio received in step E2 and stored in the memory area 112.

[0071] In step E6, the electronic control unit 11 multiplies each of the three projected values ​​of the gravitational acceleration determined by the tilt sensor 111 by the corresponding damping coefficient of the selected triplet.

[0072] In step E7, the electronic control unit 11 calculates the tilt angle from the three projection values ​​by multiplying each projection value by the corresponding attenuation coefficient.

[0073] Applying damping in this manner can offset the effect of engine 10 vibrations on the measurement of vehicle 1 tilt angle by reducing the calculated tilt angle value when vehicle 1 is likely to vibrate above the tilt threshold under conditions where vehicle 1 is unlikely to tip over. The various damping coefficients for each gear ratio and each projection axis are determined in advance, for example, in tests to calibrate them prior to mass production of vehicle 1.

[0074] Based on these tests, some coefficients may be determined to be equal to 1 so as not to attenuate the corresponding projection values ​​if they are determined not to affect the calculation of the physical tilt angle.

[0075] This method is repeated multiple times while the engine 10 is running so that the damping can be adjusted depending on the engaged gear ratio and the speed of the vehicle 1.

[0076] For example, if the vehicle 1 is in a configuration that damps angle measurements at a particular time, the user may apply the brakes and the vehicle 1 may slow down sufficiently for a region where the ratio of the measured speed value to the revolutions per minute is less than the damping interval. In this case, the vehicle 1 is at a potentially risky operating point, so damping is no longer desirable and, to avoid falsely detecting a rollover, the electronic control unit 11 then calculates the tilt angle from the measurements of the tilt sensor 111 without taking damping into account.

Claims

1. 1. A method for attenuating interference in measurements of lateral lean angles of a motorized two-wheeled vehicle (1), the vehicle (1) comprising an engine (10), an electronic control unit (11), and a speed measurement module (13), the electronic control unit (11) comprising an inclination sensor (111) and a memory area (112) containing at least one predetermined attenuation interval, the electronic control unit (11) being configured to calculate the lateral lean angle of the vehicle (1) from the measurements of the inclination sensor (111), to receive the speed value of the vehicle (1) measured by the speed measurement module (13), and to receive revolutions per minute of the engine (10), - a step (E1) in which said electronic control unit (11) receives said value of said speed of said vehicle (1) measured by said speed measurement module (13); - a step (E2) in which said electronic control unit (11) receives said revolutions per minute of said engine (10); - a step (E3) in which said electronic control unit (11) calculates said ratio between said received speed value and said received revolutions per minute; - a step (E4) in which said electronic control unit (11) compares said ratio between said received speed value and said revolutions per minute with at least one said predetermined damping interval; - if the ratio between the received speed value and the revolutions per minute is outside the damping interval, the electronic control unit (11) calculates the tilt angle without taking damping into account; - a step (E7) of said electronic control unit (11) calculating said tilt angle taking into account damping if said ratio between said received speed value and said engaged gear ratio is within said damping interval; A method comprising:

2. 2. The method of claim 1, wherein the engine (10) is connected to a mechanical transmission (12), and the step of receiving the revolutions per minute by the engine (10) by the electronic control unit (11) is followed by the step of determining the engaged gear ratio of the transmission (12).

3. 3. The method of claim 2, wherein if the electronic control unit (11) receives from the transmission (12) that a gear ratio is not engaged, the electronic control unit (11) does not perform the step of calculating the ratio between the received speed value and the received engaged gear ratio, and calculates the tilt angle without taking damping into account.

4. 4. The method according to claim 1, wherein the speed measurement module (13) has a reference speed value in its memory, and in the event of a failure of the speed measurement module (13), the speed measurement module (13) transmits this reference speed value to the electronic control unit (11).

5. 5. The method according to claim 1, wherein the tilt sensor (111) is configured to determine the projection values ​​onto three axes of the Earth's gravity, the electronic control unit (11) is configured to calculate the tilt angle from the three projection values ​​determined by the tilt sensor (111), the memory area (112) contains at least one damping coefficient, and the step of calculating the tilt angle taking damping into account corresponds to the electronic control unit (11) multiplying the at least one projection value determined by the tilt sensor (111) by the at least one damping coefficient.

6. 6. The method according to claim 5, wherein the memory area (112) contains at least three damping coefficients, each corresponding to one projection axis, and the step of calculating the tilt angle taking damping into account corresponds to the electronic control unit (11) multiplying each of the three projection values ​​determined by the tilt sensor (111) by the corresponding damping coefficient.

7. 7. The method according to claim 5 or 6, wherein the memory area (112) contains at least one damping coefficient corresponding to each of the gear ratios of the transmission (12) of the vehicle (1), and the step of calculating the tilt angle taking damping into account corresponds to the electronic control unit (11) multiplying at least one projection value determined by the tilt sensor (111) by the damping coefficient corresponding to the received gear ratio.

8. 8. The method according to claim 5, wherein the memory area (112) contains three damping coefficients, each corresponding to one projection axis, for each gear ratio of the transmission (12) of the vehicle (1), and the step of calculating the tilt angle taking damping into account corresponds to the electronic control unit (11) multiplying each of the projection values ​​determined by the tilt sensor (111) by the damping coefficient corresponding to the projection axis and the received gear ratio.

9. An electronic control unit (11) for a motorized two-wheeled vehicle (1), said electronic control unit (11) comprising an inclination sensor (111) and a memory area (112), said memory area (112) containing a predetermined damping interval, said electronic control unit (11) being configured to be connected to a speed measurement module (13) and to the engine (10) of said vehicle (1), said electronic control unit (11) comprising: receiving the speed value of the vehicle (1) measured by the speed measurement module (13); - receiving the revolutions per minute of the engine (10); - calculating the ratio between the received speed value and the received revolutions per minute; - comparing the ratio of the received speed value to the revolutions per minute with the decay interval; - calculating the tilt angle without taking into account the damping of the vehicle (1), - calculating the tilt angle taking into account the damping of the vehicle (1), The electronic control unit (11) is further configured to:

10. A motorized two-wheeled vehicle (1) comprising an engine (10) connected to a transmission (12), a speed measurement module (13) and an electronic control unit (11) according to claim 9.

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