Method for attenuating disturbances in measurement of tilt angle of vehicle

Abstract

The invention relates to a method for attenuating disturbances in measurements of a tilt angle of a vehicle comprising an electronic control unit (11) configured to calculate a lateral tilt angle of the vehicle from measurements of a tilt sensor (111), the method comprises the steps of: receiving (E1) a speed value of the vehicle (1) measured by the speed measurement module (13); receiving (E2) a revolution per minute of the engine (10); calculating (E3) a ratio between the received speed value and the received revolutions per minute; comparing (E7) the ratio between the received speed value and the number of revolutions per minute with an attenuation interval; if the ratio is outside the attenuation interval, calculating a tilt angle without attenuation; if the ratio is within an attenuation interval, an attenuated tilt angle is calculated (E7).

Description

Technical Field

[0001] This invention relates to the field of motorized two-wheeled vehicles, and more particularly to the measurement of the lateral tilt angle of motorized two-wheeled vehicles. Background Technology

[0002] To improve driver safety, many motorized two-wheeled vehicles are now equipped with systems that can take direct action on the vehicle's operation without driver intervention once an emergency is detected.

[0003] Manufacturers of motorized two-wheeled vehicles typically install tilt sensors in their vehicles. These sensors specifically measure the vehicle's lateral tilt. These sensors are configured with a maximum tilt threshold; exceeding this threshold indicates that the vehicle is falling, triggering an engine stop and thus ensuring driver safety.

[0004] For example, if the threshold is 60° relative to the vertical direction defined by Earth's gravity, and the vehicle's actual tilt angle exceeds 60°, the vehicle is considered to be falling and the engine stops.

[0005] The device can also prevent the engine from starting if the vehicle tilts beyond a certain threshold when the user attempts to start the vehicle.

[0006] The first generation of mechanical tilt sensors were attached to the vehicle's chassis. These sensors contained a weight (such as a ball bearing) that moved to close electrical contacts when the vehicle tilted beyond a given tilt. Therefore, the inertia of these weights determined the sensor's sensitivity to vehicle tilt, and consequently, the accuracy of the angle measurement.

[0007] However, these sensors are bulky and subject to significant limitations in attaching to the vehicle's chassis. Therefore, a new generation of sensors is currently being used, consisting of an electronic control unit containing a MEMS accelerometer (MEMS stands for Microelectromechanical Systems). This type of sensor can be mounted directly on the engine, for example, on the intake manifold, or near the engine.

[0008] However, because the sensors are close to the engine, vibrations generated by the engine can affect the sensors and interfere with the measurement of the tilt angle. The risk is that this interference could cause the maximum tilt threshold to be artificially exceeded for a sufficient period of time, causing the electronic control unit to interpret it as a fall and trigger the engine stop function during normal vehicle operation.

[0009] The sampling of tilt angle measurements complicates this problem. Specifically, disturbances associated with engine operation are periodic. Therefore, if the sampling frequency is set independently of the disturbance frequency (according to the Nyquist-Shannon sampling theorem), the period of the reconstructed signal may be longer than the period of the engine's mechanical vibration. This effect is called aliasing and can therefore lead to artificially exceeding the maximum tilt threshold for longer periods, thereby increasing the risk of the electronic control unit triggering an engine shutdown.

[0010] One approach to reduce aliasing is to increase the sampling frequency used in tilt angle measurements to capture the actual period of interference. However, this method is energy-intensive and demands high computer performance, which may become saturated, limiting its ability to perform and store more measurements. Furthermore, even without aliasing, engine vibrations cannot prevent artificially exceeding the tilt threshold during tilt angle measurements.

[0011] Therefore, a simple and effective solution is needed that makes it possible to overcome these shortcomings at least in part. Summary of the Invention

[0012] Therefore, a first aspect of the present invention relates to a method for attenuating interference in the measurement of the lateral tilt angle of a motorized two-wheeled vehicle, the vehicle including an engine connected to a mechanical gearbox, an electronic control unit, and a speed measurement module, the electronic control unit including a tilt sensor and a storage area containing at least one predetermined attenuation range, the electronic control unit being configured to calculate the lateral tilt angle of the vehicle based on the measurement of the tilt sensor, receive the vehicle speed value measured by the speed measurement module, and receive the engine's revolutions per minute, the method comprising the following steps:

[0013] - The electronic control unit receives the vehicle's speed value measured by the speed measurement module.

[0014] - The engine's revolutions per minute are received by the electronic control unit.

[0015] - The electronic control unit calculates the ratio between the received speed value and the received revolutions per minute.

[0016] - The electronic control unit compares the ratio of the received speed value to revolutions per minute with at least one attenuation interval.

[0017] -If the ratio between the received speed value and revolutions per minute is outside the attenuation range, the electronic control unit calculates the tilt angle without attenuation.

[0018] -If the ratio between the received speed value and revolutions per minute is within the attenuation range, the electronic control unit calculates the attenuated tilt angle.

[0019] The method according to the invention thus attenuates the influence of engine vibration on the determination of the vehicle's lateral tilt angle. When these vibrations are considered likely to cause interference in the angle measurement, potentially exceeding the tilt threshold long enough to trigger the vehicle's stop function, the electronic control unit attenuates the component of the tilt sensor measurement that has the greatest impact on the tilt angle measurement. Therefore, the tilt angle still represents the vehicle's physical tilt, but the vibration is less likely to cause oscillations in the calculated tilt angle (which could then cross the tilt threshold). When the ratio between the received speed value and revolutions per minute (RPM) is within the attenuation range, the vehicle has a speed consistent with the engine speed and is therefore less likely to be in the process of falling. Thus, this attenuation method avoids erroneous fall detection. In contrast, if the ratio between the received speed value and RPM is outside this range, inconsistency exists, potentially indicating a problem, and therefore it is safer not to attenuate the signal in order to send the engine stop command as soon as possible.

[0020] Preferably, after the step of connecting the engine to the mechanical gearbox and receiving the engine's revolutions per minute (RPM) from the electronic control unit, the step of determining the gear ratio of the gearbox engagement is followed. The gear ratio can be determined directly by sending a signal from the gearbox to the electronic control unit, or it can be determined by calculating the ratio between the measured speed and the RPM in the engine, and can be used to create redundancy when verifying the application conditions of the method according to the invention.

[0021] Advantageously, if the electronic control unit receives a message from the gearbox indicating no gear ratio engagement, it calculates the tilt angle without attenuation, without performing the step of calculating the ratio between the received speed value and the received engaged gear ratio. In this case, engine vibration is minimal and therefore requires no attenuation. The engine may be running (e.g., if the vehicle is stationary and about to accelerate), thus the measurement of the vehicle's tilt angle is relevant.

[0022] In a preferred embodiment, the speed measurement module stores a reference speed value in its memory. In the event of a speed measurement module failure, the speed measurement module sends this reference speed value to the electronic control unit. Therefore, even in the event of a speed measurement module failure, the tilt angle measurement and the method for attenuating the measurement can still function normally.

[0023] In one embodiment of the invention, a tilt sensor is configured to determine the projection of Earth's gravity onto three axes, and an electronic control unit is configured to calculate a tilt angle based on the three projections determined by the tilt sensor, with a storage area containing at least one attenuation coefficient. The step of calculating the attenuated tilt angle corresponds to the electronic control unit multiplying the at least one projection determined by the tilt sensor by the at least one attenuation coefficient. This attenuation can be applied to one of the projections measured by the tilt sensor. Therefore, if it is determined that one of the projections has no first-order effect on the calculation of the tilt angle, the electronic control unit does not need to attenuate that projection in the calculation. For example, when the electronic control unit can apply a modification to the projection that does not or only slightly alters the calculated tilt angle, it can determine that the projection has no first-order effect by performing a self-test by the electronic control unit.

[0024] Advantageously, in this embodiment, the storage area includes attenuation coefficients, each corresponding to a projection axis, and the step of calculating the attenuated tilt angle corresponds to the electronic control unit multiplying each of the three projections determined by the tilt sensor by its corresponding attenuation coefficient. Therefore, attenuation can be appropriately applied to each of the three projections measured by the tilt sensor.

[0025] Advantageously, the storage area contains at least one attenuation coefficient corresponding to each of the gear ratios in the vehicle gearbox, and the step of calculating the attenuated tilt angle corresponds to the electronic control unit multiplying at least one projection determined by the tilt sensor with the attenuation coefficient corresponding to the received gear ratio. Thus, the electronic control unit applies different attenuations depending on the gear ratios engaged in the vehicle gearbox.

[0026] Preferably, in this embodiment, for each gear ratio in the vehicle gearbox, the storage area contains three attenuation coefficients, each attenuation coefficient corresponding to a projection axis, and the step of calculating the attenuated tilt angle corresponds to the electronic control unit multiplying each of the projections determined by the tilt sensor with the attenuation coefficient corresponding to that projection axis and the received gear ratio. Therefore, the attenuation is adjusted according to the vehicle's operating conditions.

[0027] According to another aspect, the present invention also relates to an electronic control unit for a motorized two-wheeled vehicle, the electronic control unit including a tilt sensor and a storage area containing at least one attenuation range, and the electronic control unit being configured to connect to a speed measurement module and a mechanical gearbox of the vehicle's engine, the electronic control unit being further configured to:

[0028] - Receives the vehicle's speed value measured by the speed measurement module.

[0029] -Receive the gear ratio engaged in the gearbox

[0030] - Calculate the ratio between the received speed value and the received gear ratio of engagement.

[0031] - Compare the ratio between the received speed value and the engaged gear ratio with a first threshold.

[0032] - Calculate the vehicle's tilt angle without attenuation.

[0033] - Calculate the vehicle's decaying tilt angle.

[0034] According to another aspect, the present invention also relates to a motorized two-wheeled vehicle, which includes an engine connected to a gearbox, a speed measurement module, and an electronic control unit such as those described. Attached Figure Description

[0035] Other features and advantages of the invention will become more apparent upon reading the following description. This description is illustrative only and should be read in conjunction with the accompanying drawings, in which:

[0036] [ Figure 1 ] Figure 1 A schematic illustration shows a motorized two-wheeled vehicle in which the method according to the invention is applied.

[0037] [ Figure 2 ] Figure 2 An electronic control unit that implements this method is illustrated schematically.

[0038] [ Figure 3 ] Figure 3 The diagram schematically illustrates the lateral tilt of the vehicle relative to the tilt threshold that triggers the engine stop function.

[0039] [ Figure 4 ] Figure 4 The sequence of steps according to the method of the present invention is illustrated schematically. Detailed Implementation

[0040] The method according to the present invention is applicable to motorized two-wheeled vehicles 1.

[0041] Vehicle 1

[0042] like Figure 1 As shown, vehicle 1 includes an engine 10, an electronic control unit 11, a mechanical gearbox 12, a speed measurement module 13, and a communication link 14.

[0043] Engine 10

[0044] The engine 10 can generate the torque required to drive the wheels of the vehicle 1 when the vehicle is moving. This torque is transmitted via the rotation of a shaft at a certain number of revolutions per minute (also known as engine speed).

[0045] Engine 10 is connected to gearbox 12.

[0046] The engine 10 can operate without any gears in the mechanical gearbox 12 being engaged (e.g., when the vehicle 1 is started).

[0047] Gearbox 12 is used to transmit engine speed to the wheels. The ratio between engine speed and wheel speed will vary depending on the gear ratios engaged.

[0048] Electronic control unit 11

[0049] like Figure 2 As shown, the electronic control unit 11 includes a tilt sensor 111 and a storage area 112.

[0050] The tilt sensor 111 is preferably a MEMS accelerometer, configured to calculate the projection of the Earth's gravity onto the three axes of the reference frame.

[0051] The electronic control unit 11 is configured to calculate the lateral tilt angle of the vehicle 1 about the vertical direction (Z-axis) of the earth based on three projections measured by the tilt sensor 111.

[0052] Storage area 112 is configured to store information. Specifically, storage area 112 contains an angle θs corresponding to a tilt threshold; if this threshold is exceeded, the electronic control unit 1 assumes that vehicle 1 is in the process of falling. Figure 3 As shown.

[0053] exist Figure 3 In this diagram, the Z-axis corresponds to the vertical direction of the Earth, and the Y-axis corresponds to the horizontal direction perpendicular to vehicle 1. The tilt angle is the angle formed between the Y-axis and vehicle 1.

[0054] Storage area 112 also contains at least one decay range corresponding to the ratio between the speed of vehicle 1 and the revolutions per minute in engine 10.

[0055] This range corresponds to the value of this ratio under normal moving conditions of vehicle 1 (especially when it does not fall).

[0056] Storage area 112 also includes multiple storage attenuation coefficients.

[0057] Preferably, the storage region 112 contains a coefficient for each of the three axes of the reference frame of the tilt sensor 111 and for each gear ratio of the gearbox 12.

[0058] Therefore, for a vehicle 1 having a gearbox 12 including, for example, 5 gear ratios, the storage area 112 contains 15 coefficients.

[0059] Advantageously, the coefficients stored in storage area 112 are less than or equal to 1.

[0060] In another embodiment, one or more attenuation coefficients may be a low-pass filter that does not attenuate low frequencies (where aliasing is less noticeable) but attenuates high frequencies.

[0061] The electronic control unit 11 is configured to calculate a decayed tilt angle by multiplying at least one projection measured by the tilt sensor 111 by a corresponding coefficient, and is configured to calculate the tilt angle based on the value.

[0062] The electronic control unit 11 is configured to compare the calculated tilt angle with the tilt threshold θs.

[0063] The tilt threshold θs corresponds to the angle at which the electronic control unit 11 believes the vehicle 1 is falling.

[0064] The electronic control unit 11 is configured to perform the function of stopping the engine 10 of the vehicle 1 when the measured lateral tilt angle is greater than the tilt threshold θs.

[0065] The electronic control unit 11 is configured to receive the revolutions per minute of the engine 10 via the communication link 14.

[0066] The electronic control unit 11 is configured to receive the gear ratio engaged in the gearbox 12 of the engine 10 via a communication link 14.

[0067] The electronic control unit 11 is also configured to determine the gear ratio engaged in the gearbox 12 of the engine 10 by calculating the ratio between the speed of the vehicle 1 and the revolutions per minute of the engine 10.

[0068] The electronic control unit 11 is configured to receive the speed value of the vehicle 1 measured by the speed measurement module 13 via the communication link 14.

[0069] Gearbox 12

[0070] Gearbox 12 has multiple gear ratios, allowing the torque generated by engine 10 to match the performance required by the user of vehicle 1.

[0071] Gearbox 12 is mechanically connected to engine 10, such as Figure 1 As shown.

[0072] The gearbox 12 is configured to send a signal via communication link 14 to the electronic control unit 11 indicating which gear ratio is engaged or whether no gear ratio is engaged.

[0073] Speed ​​measurement module 13

[0074] The speed measurement module 13 is configured to measure the moving speed of vehicle 1.

[0075] The speed measurement module 13 can be of various types, such as a tachometer located on one of the wheels of the vehicle 1.

[0076] Communication Link 14

[0077] Communication link 14 allows communication between the electronic control unit 11 and the engine 10, and between the gearbox 12 and the speed measurement module 13.

[0078] Preferably, communication link 14 is a wired communication link, such as a CAN type.

[0079] Example

[0080] When vehicle 1 moves, engine 10 is running. Vibrations caused by the running of engine 10 are transmitted to electronic control unit 11 and sensed by tilt sensor 111.

[0081] Therefore, the angle calculated by the electronic control unit 11 based on the measurement of the tilt sensor 111 will take these vibrations into account.

[0082] The method according to the invention aims to attenuate the effect of vibration on tilt angle calculation in configurations where excessive vibration occurs.

[0083] In the 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.

[0084] In the second step E2, the electronic control unit 11 receives the engine speed per minute (rpm) of the engine 10 and the gear ratio engaged in the gearbox 12. If, in this step, the electronic control unit 11 receives no gear ratio engaged, the method stops.

[0085] Specifically, this particular situation indicates that vehicle 1 is stationary or moving at a very low speed and is not driven by engine 10, and therefore does not require damping of vibration effects.

[0086] It makes no difference whether steps E1 and E2 are performed sequentially or simultaneously.

[0087] In step E3, the electronic control unit 11 calculates the ratio between the speed value received from the speed measurement module 13 and the engine speed per minute of the engine 10.

[0088] In step E4, the electronic control unit 11 compares the calculated ratio with the attenuation range stored in the storage area 112.

[0089] This range corresponds to the expected operating point of vehicle 1 under normal conditions. Under these conditions, vehicle 1 is unlikely to tilt more than the tilt angle threshold θs, and therefore attenuation of the signal used to calculate the tilt angle is appropriate to prevent the electronic control unit 11 from erroneously detecting a fall of vehicle 1 and thereby triggering the engine stop function 10.

[0090] If the calculated ratio is outside the attenuation range, the operating point of vehicle 1 may pose a risk of falling. To avoid erroneously detecting a fall, the electronic control unit 11 measures the tilt angle without attenuation in step E5*, and the attenuation method restarts from step E1.

[0091] If the calculated ratio is within the decay range, the electronic control unit 11 detects that the vehicle 1 is unlikely to fall.

[0092] In this case, the electronic control unit 11 selects the gear ratio corresponding to the engagement received in step E2 in step E5 and stores the triplet attenuation coefficient in the storage area 112.

[0093] In step E6, the electronic control unit 11 multiplies each of the three projections of the gravitational acceleration determined by the tilt sensor 111 with the corresponding attenuation coefficient of the selected triplet.

[0094] In step E7, the electronic control unit 11 calculates the tilt angle based on the three projections and multiplies each projection by the corresponding attenuation coefficient.

[0095] Therefore, the applied attenuation can offset the effect of engine 10 vibration on the measurement of vehicle 1's tilt angle. In cases where vehicle 1 is unlikely to fall, the calculated tilt angle value is reduced when it might oscillate beyond a tilt threshold. The individual attenuation coefficients used for each gear ratio and each projected axis are predetermined, for example, during calibration testing of vehicle 1 before mass production.

[0096] Based on these tests, it can be determined that certain coefficients are equal to one so as not to attenuate the corresponding projection, if it is determined that it does not affect the calculation of the physical tilt angle.

[0097] This method repeats as long as engine 10 is running, so that the attenuation can be adjusted according to the engaged gear ratio and the speed of vehicle 1.

[0098] For example, if vehicle 1 is in the angle measurement attenuation configuration at a given time and the user brakes, vehicle 1 may decelerate sufficiently such that the region in which the measured speed value to revolutions per minute falls within the attenuation range. In this case, attenuation is no longer desired because vehicle 1 is at a potentially dangerous operating point, and electronic control unit 11 will calculate the tilt angle based on the measurement from tilt sensor 111 without attenuation to avoid falsely detecting a fall.

Claims

1. A method for attenuating interference in the measurement of the lateral tilt angle of a motorized two-wheeled vehicle (1), the vehicle (1) including an engine (10), an electronic control unit (11), and a speed measurement module (13), the electronic control unit (11) including a tilt sensor (111) and a storage area (112) containing at least one predetermined attenuation interval, the electronic control unit (11) being configured to calculate the lateral tilt angle of the vehicle (1) based on the measurement of the tilt sensor (111), receive the speed value of the vehicle (1) measured by the speed measurement module (13), and receive the revolutions per minute of the engine (10), the method comprising the steps of: - The electronic control unit (11) receives (E1) the speed value of the vehicle (1) measured by the speed measurement module (13). - The electronic control unit (11) receives (E2) the revolutions per minute of the engine (10). - The ratio between the speed value received by the electronic control unit (11) and the received revolutions per minute is calculated by (E3). - The electronic control unit (11) compares the ratio between the received speed value and revolutions per minute with the at least one predetermined attenuation range (E4). If the ratio between the received speed value and revolutions per minute is outside the attenuation range, the electronic control unit (11) calculates the tilt angle without attenuation. -If the ratio between the received speed value and the engaged gear ratio is within the attenuation range, the electronic control unit (11) calculates (E7) the attenuated tilt angle.

2. The method according to claim 1, wherein, The engine (10) is connected to the mechanical gearbox (12), and wherein, after the step of receiving the revolutions per minute of the engine (10) by the electronic control unit (11), the step of determining the gear ratio of engagement of the gearbox (12) follows.

3. The method according to the preceding claim, wherein, If the electronic control unit (11) receives a message from the gearbox (12) that no gear ratio is engaged, the electronic control unit (11) calculates the tilt angle without attenuation, without performing the step of calculating the ratio between the received speed value and the received engaged gear ratio.

4. The method according to any one of the preceding claims, wherein, The speed measurement module (13) has a reference speed value in its memory, and in the event of a malfunction of the speed measurement module (13), the speed measurement module (13) sends this reference speed value to the electronic control unit (11).

5. The method according to any one of the preceding claims, wherein, The tilt sensor (111) is configured to determine the projection of the Earth's gravity onto three axes, the electronic control unit (11) is configured to calculate the tilt angle based on the three projections determined by the tilt sensor (111), and the storage area (112) contains at least one attenuation coefficient, wherein the step of calculating the attenuated tilt angle corresponds to the electronic control unit (11) multiplying the at least one projection determined by the tilt sensor (111) by the at least one attenuation coefficient.

6. The method according to the preceding claim, wherein, The storage area (112) contains at least three attenuation coefficients, each attenuation coefficient corresponding to a projection axis, and wherein the step of calculating the tilt angle with attenuation corresponds to the electronic control unit (11) multiplying each of the three projections determined by the tilt sensor (111) with the corresponding attenuation coefficient.

7. The method according to any one of claims 5 and 6, wherein, The storage area (112) contains at least one attenuation coefficient corresponding to each of the gear ratios of the gearbox (12) of the vehicle (1), and wherein the step of calculating the tilt angle with attenuation corresponds to the electronic control unit (11) multiplying at least one projection determined by the tilt sensor (111) with the attenuation coefficient corresponding to the received gear ratio.

8. The method according to any one of claims 5 to 7, wherein, For each of the gear ratios in the gearbox (12) of the vehicle (11), the storage area (112) contains three attenuation coefficients, each attenuation coefficient corresponding to a projection axis, and wherein the step of calculating the tilt angle with attenuation corresponds to the electronic control unit (11) multiplying each of the projections determined by the tilt sensor (111) with the attenuation coefficient corresponding to the projection axis and the received gear ratio.

9. An electronic control unit (11) for a motorized two-wheeled vehicle (1), the electronic control unit (11) including a tilt sensor (111) and a storage area (112) containing a predetermined attenuation range, and the electronic control unit (11) being configured to connect to a speed measurement module (13) and an engine (10) of the vehicle (1), the electronic control unit (11) being further configured to: - Receive the speed value of the vehicle (1) measured by the speed measurement module (13), - Receive the revolutions per minute of the engine (10), - Calculate the ratio between the received speed value and the received revolutions per minute. - Compare the ratio between the received speed value and revolutions per minute with the attenuation range. - Calculate the undamped tilt angle of the vehicle (1), - Calculate the attenuated tilt angle of the vehicle (1).

10. A motorized two-wheeled vehicle (1) comprising an engine (10) connected to a gearbox (12), a speed measurement module (13), and an electronic control unit (11) as described in the preceding claims.

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