DE102016206101A1 - Method for determining the lateral acceleration of a motor vehicle - Google Patents

Abstract

Method for determining the lateral acceleration of a motor vehicle (10), in particular a motorcycle or a car, wherein the motor vehicle (10) comprises a first sensor (14) for determining a speed of the motor vehicle (10) and a second sensor (16) for determining a yaw rate a vertical axis (18c) of the motor vehicle (10), wherein from the speed and the yaw rate, the lateral acceleration of the motor vehicle (10) is calculated. In addition, a motor vehicle (10), in particular a motorcycle or a car, for applying the method according to one of the preceding claims is described.

Description

The invention relates to a method for determining the lateral acceleration of a motor vehicle and a motor vehicle for the application of such a method.

One way to determine the lateral acceleration is, for example, in the WO2010 / 054887A1 discloses in which the banking angle of a motorcycle is to be determined. In this case, the lateral acceleration is measured by means of the lateral acceleration sensor, wherein the lateral acceleration and the acceleration in the direction of the vertical axis are used to determine the angle of inclination. The measured values of lateral acceleration sensors are influenced by gravity, especially at high angles of inclination. The use of lateral acceleration sensors is particularly advantageous in passenger cars, since in this case relatively low roll angles are achieved. In the case of motorcycles, inclinations of up to 60 degrees can be achieved, so that gravitational force has a major influence on the measured value of the lateral acceleration sensor. In addition, such lateral acceleration sensors must be installed in a corresponding motor vehicle.

It is therefore an object to provide a method for determining the lateral acceleration of a motor vehicle, which can be carried out in a simple manner and with the saving of additional sensors, wherein the determined lateral acceleration is not influenced by the gravitational attraction.

This object is achieved by a method according to claim 1. In the dependent claims according to advantageous embodiment variants are explained.

Such a method can be used for example in motor vehicles, especially motorcycles and cars. In this case, the motor vehicle has at least one first sensor for determining a speed of the vehicle and a second sensor for determining the yaw rate determined about a vertical axis of the vehicle. In this case, the second sensor can determine the yaw rate directly or the yaw rate can be determined from the determined sensor values. This yaw rate corresponds to a rotational acceleration of the motor vehicle about its vertical axis.

In this case, a lateral acceleration of the motor vehicle is calculated from the speed and the yaw rate.

in Zusammenhang gestellt werden. Dabei entspricht der Kreisumfang der Geschwindigkeit des Fahrzeugs multipliziert mit der Zeit, die für eine Rotations des Kraftfahrzeugs um 360° benötigt wird.The yaw rate ω _z , which describes a rotational speed about the vertical axis of the motor vehicle, the vehicle speed ν and the circumference 2πr can be determined according to FIG

be related. The circumference corresponds to the speed of the vehicle multiplied by the time required for a rotation of the motor vehicle through 360 °.

dar.The centrifugal force here represents a relationship between the circle radius r, the velocity ν and the lateral acceleration a according to

represents.

If one puts these connections into one another and converts a to the lateral acceleration, one obtains a · = ν · ω _z · π / 180 °.

It is therefore proposed that the lateral acceleration a from the speed ν and the yaw rate ω _z by the formula a = ν · ω _z · π / 180 ° is determined.

In this case, a sensor for determining the vehicle speed and a rotation rate sensor are already installed on most motor vehicles. The measured values of such sensors are already used for a wide variety of tasks. The lateral acceleration can thus be determined from measured values of sensors that are already installed in almost every vehicle.

With particular advantage, a banking angle of the motor vehicle, in particular the motorcycle, is determined from the lateral acceleration.

In this case, the lateral acceleration determined from the yaw rate and the vehicle speed correlates with the inclination on a motorcycle, due to the influence of the oblique position on the measuring axis of the yaw rate. The skew angle can thus be determined directly from the lateral acceleration. In addition, the resulting lateral acceleration and the inclination are not influenced by the gravitational force.

It is further proposed a method for determining a banking angle of a motor vehicle, in particular a motorcycle or a car, wherein initially a lateral acceleration is determined according to at least one of the previously described embodiments, wherein from the determined lateral acceleration a banking angle is determined.

The transverse acceleration determined according to the preceding embodiments and, if appropriate, the angle of inclination, has an error which increases with the angle of inclination β of the motor vehicle and whose error course is essentially determined by cosβ.

The ascertained lateral acceleration is smaller than the actual lateral acceleration when the banking angle β increases, but it is possible to differentiate qualitatively correctly between different driving states of the motor vehicle. In a motorcycle, for example, between low inclination in a straight ahead, or cornering near the maximum angle of inclination. The accuracy of the determined lateral acceleration and possibly derived therefrom inclined position is completely sufficient, for example, for the adjustment of suspension elements on the motor vehicle.

With particular advantage, the determined lateral acceleration, referred to as the first lateral acceleration in the following section, is compared with a measured lateral acceleration, which is measured directly by a lateral acceleration sensor and referred to as the second lateral acceleration in the following section, in order to provide a roll angle of the motor vehicle.

In this case, the roll angle of the motor vehicle is essentially also a banking angle, which remains in a car, for example, within an angle of 20 ° or 25 °. The determined first lateral acceleration decreases with increasing bank angle or roll angle according to cosβ, whereas the measured second lateral acceleration has a negligible error at a small roll angle. By comparing the determined first transverse acceleration and the measured second transverse acceleration, in particular by their difference value, the roll angle can be determined.

In an advantageous embodiment variant, a transverse acceleration or banking angle determined in accordance with the preceding embodiments is used for adjusting chassis elements of the motor vehicle, in particular for adjusting a damping force of a vibration damper.

As a result, can be realized at large inclinations cost-effective over-damping of the tire by correct adjustment of the suspension elements.

Furthermore, a motor vehicle, in particular a motorcycle or a car, for applying the method according to one of the claims 1 to 5 or at least one of the previously described embodiments proposed.

The invention will be further explained by way of example with reference to the following two figures. Show it:

1 a schematic structure of a motorcycle;

2 Comparison of measured values of different sensor arrangements.

1 shows a schematically illustrated motorcycle 10 with several suspension elements 12 , The chassis elements 12 can be formed here, for example, by a strut and a fork or other known suspension elements. However, these are only shown schematically as a vibration damper.

The motorcycle 10 further comprises a first sensor 14 to determine the speed ν of the motorcycle 10 , The first sensor 14 is here on the front wheel 15 arranged, in particular on a front wheel 15 associated fork. This can, for example, a rotational speed of the front wheel 15 determine and from this the speed ν of the motorcycle 10 determine.

Furthermore, the motorcycle includes 10 a second sensor 16 , This second sensor 16 is hereby an example of the structure 18 arranged and designed as a rotation rate sensor. The second sensor 16 Here, a rolling acceleration, a roll speed, a pitch acceleration, a pitching speed, a yaw acceleration and a yaw rate about a longitudinal axis 18a , a transverse axis 18b as well as a vertical axis 18c determine.

In this case, a rotational speed is detected, wherein rotation arrows are drawn to illustrate the rotational movement. The transverse axis 18b is shown at an angle for better representation, but this protrudes into the image plane or protrudes from this.

The motorcycle 10 can while driving a slope about its longitudinal axis 18a perform so that the vertical axis 18c opposite a surface normal 20a a roadway 20 is inclined by a banking angle β. Here is the vertical axis 18c by way of example with a skew angle β with respect to the surface normal 20a located.

At the same time the motorcycle goes 10 when cornering over in an inclined position, wherein the obliquity substantially of the radius of curvature r and the speed v of the motorcycle 10 depends. One on the bike 10 acting lateral acceleration correlates with also with the curve radius r and the speed ν of the motorcycle. The lateral acceleration a of the motorcycle 10 can be according to the previous versions by a = ν · ω _z · π / 180 ° determine.

It is in the 2 a comparison between the banking angle β, determined by a complex and precise structure, which can be used, for example, also for inclined ABS systems and traction controls, as well as the lateral acceleration a, which is determined according to the embodiments described in the foregoing. It is along the X axis 22 the time is plotted, as well as along the respective Y-axis 24a an angle in ° (degrees), along the Y axis 24b an acceleration, for example in cm / s², as well as along the Y-axis 24b the speed.

To determine the in 2 The values shown were traversed by a motorcycle with circles of different radii and at different speeds. The history 26 shows the determined inclination of a high-precision system. The history 28 on the other hand, represents the lateral acceleration, which was determined according to a system according to the previous statements. In addition, in the course 30 the speed of the motorcycle 10 shown. It can be seen that the lateral acceleration signal matches the skew signal qualitatively very well.

From the determined lateral acceleration of the associated skew angle β can be determined or calculated. It is possible from the determined lateral acceleration or a skew angle determined therefrom, the vehicle elements 12 of the motorcycle 10 to adjust. Likewise, a clear distinction can be made between a high angle and a low angle. As a result, in particular, an associated vibration damper can be reduced in its damping effect when cornering at high banking angle, so that, for example, an overloading of the tire is prevented. The quality of the detected signal is perfect for adjusting suspension components.

This example explained method for determining the lateral acceleration can be used substantially unchanged in cars.

LIST OF REFERENCE NUMBERS

10

motorcycle

12

chassis element

14

first sensor / speed sensor

15

front

16

second sensor / yaw rate sensor

18

construction

18a

longitudinal axis

18b

transverse axis

18c

vertical axis

20

roadway

20a

surface normal

22

X axis

24, a, b, c

Y-axis

26

History / tilt

28

Course / determined lateral acceleration

30

Course / Speed

β

Bank angle

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2010/054887 A1 [0002]

Claims (7)

Method for determining the lateral acceleration of a motor vehicle ( 10 ), in particular a motorcycle or passenger car, wherein - the motor vehicle ( 10 ) a first sensor ( 14 ) for determining a speed of the motor vehicle ( 10 ) and a second sensor ( 16 ) for determining a yaw rate about a vertical axis ( 18c ) of the motor vehicle ( 10 ), wherein - from the speed and the yaw rate, the lateral acceleration of the motor vehicle ( 10 ) is calculated. Method according to one of the preceding claims, characterized in that the lateral acceleration a from the speed v and the te ω _z by the formula a = ν · ω _z · π / 180 ° is determined. Method according to one of the preceding claims, characterized in that from the lateral acceleration, a banking angle (β) of the motor vehicle ( 10 ) is determined. Method for determining a banking angle (β) of a motor vehicle ( 10 ), in particular a motorcycle or a car, wherein initially a lateral acceleration is determined according to one of the preceding claims, wherein from the determined lateral acceleration a banking angle (β) is determined. Method for determining a roll angle of a motor vehicle ( 10 ), in particular a car, wherein first a first lateral acceleration is determined according to one of the preceding claims, and wherein a second lateral acceleration is measured by means of a lateral acceleration sensor, wherein from the first lateral acceleration and the second lateral acceleration, in particular from the difference value, a roll angle of the motor vehicle ( 10 ) is determined. Method according to one of the preceding claims, characterized in that determined lateral acceleration or angle of inclination (β) for the adjustment of suspension elements ( 12 ) of the motor vehicle ( 10 ) is used. Motor vehicle ( 10 ), in particular a motorcycle or a car, for the application of the method according to one of the preceding claims.

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