DE102017211376A1 - Method and control device for determining an inclination of a vehicle in the direction of travel - Google Patents

Abstract

A method for determining an inclination of a vehicle in the direction of travel, wherein an inclination of the vehicle in the direction of travel on the basis of data on a longitudinal acceleration of the vehicle is calculated, and wherein the calculated inclination is plausibility dependent on an ambient air pressure and / or a change in the ambient air pressure.

Description

The invention relates to a method for determining an inclination of a vehicle in the direction of travel. Furthermore, the invention relates to a control device for determining an inclination of a vehicle in the direction of travel.

From the DE 10 2010 041 967 A1 A method is known for determining a vehicle inclination in the direction of travel, in which the inclination of the vehicle is determined from the output signals of a yaw rate and acceleration sensor. The acceleration sensor provides a measurement signal over the longitudinal acceleration of the vehicle.

From the DE 10 2013 213 291 A1 Another method for determining the inclination of a motor vehicle is known, namely details that serve to improve the inclination calculation when cornering the vehicle.

From the DE 199 39 938 A1 It is known, depending on data of a navigation system to determine the inclination of a vehicle. The navigation system provides road information and / or inclination parameters.

The known from the prior art determination of the inclination of a vehicle in the direction of travel is subject to errors. This is because, for example, a longitudinal acceleration sensor, which provides a longitudinal acceleration signal on the basis of which the inclination is calculated, may be installed in a misalignment in the vehicle, so that the longitudinal acceleration sensor provides a nonzero acceleration value even if the vehicle is stationary. As a result, the determination of the inclination of the vehicle in the direction of travel is affected.

There is therefore a need to improve the determination of the inclination of a vehicle in the direction of travel.

On this basis, the invention is based on the object to provide a novel method for determining the inclination of a vehicle in the direction of travel and a control device for operating a motor vehicle.

This object is achieved by a method for determining an inclination of a vehicle in the direction of travel according to claim 1.

According to the invention, the calculated inclination is made plausible depending on an ambient air pressure and / or a change in the ambient air pressure. The invention allows in a particularly advantageous manner, the plausibility of a calculated depending on the longitudinal acceleration of the motor vehicle inclination.

According to a first advantageous development of the invention, a first change in altitude along the traveled route is calculated as a function of the calculated inclination and a traveled route. Depending on the ambient air pressure and / or the change in the ambient air pressure along the covered route, a second change in altitude along the traveled distance is calculated. Depending on a comparison between the first height change and the second height change, the calculated inclination of the vehicle in the direction of travel is made plausible.

According to a second advantageous development of the invention, which can be used as an alternative or in addition to the above first advantageous development, depending on the calculated inclination and a traveled distance a first absolute height is calculated at least one point of the route. Depending on the ambient air pressure and / or the change in the ambient air pressure along the traveled route, a second absolute altitude is calculated at the or each point of the route on which the first absolute altitude is calculated. Depending on a comparison between the first of the first absolute altitude and the corresponding second absolute altitude, the calculated inclination of the vehicle in the direction of travel is plausibility-checked.

With these developments of the invention it is proposed to check the plausibility of the inclination of the motor vehicle calculated as a function of the longitudinal acceleration of the motor vehicle by means of a comparison between differently calculated height changes or differently calculated heights. For plausibility of the calculated inclination, the first height change is compared with the second height change and / or the first absolute height with the corresponding second absolute height. The invention allows in a particularly advantageous manner, the plausibility of the calculated depending on the longitudinal acceleration of the motor vehicle inclination.

Then, when the deviation between the first altitude change and the second altitude change and / or the deviation between the first absolute altitude and the corresponding second absolute altitude is less than a threshold, a plausibly calculated tilt of the vehicle in the direction of travel is deduced. On the other hand, if the deviation between the first height change and the second height change and / or the deviation between the first absolute height and the corresponding second absolute height is greater than is the limit, is closed to a non-plausibly calculated inclination of the vehicle in the direction of travel. These details are also used to simply and favorably check the plausibility of the vehicle in the direction of travel. According to an advantageous development, the limit value is determined as a function of the length of the traveled route. This refinement is based on the finding that the limit value can be greater, the greater the distance traveled.

According to an advantageous development, the plausibility check is reset and restarted after a defined route and / or after a defined calculation period and / or when wheel slip is detected at the edges of the vehicle. This development is based on the invention that to limit sum errors and / or to minimize or exclude weather-related changes in ambient pressure and / or to avoid a plausibility disturbing Radschlupfes the plausibility should be reset and restarted when a defined route was covered and / or a defined calculation period has expired and / or a wheel slip has been detected.

According to an advantageous development of the invention, on the basis of the deviation between the first height change and the second height change and / or on the basis of the deviation between the first absolute height and the corresponding second absolute height, a measurement signal of a longitudinal acceleration sensor and / or the calculated inclination of the vehicle in Corrected direction of travel. According to this advantageous development, the measurement signal of a longitudinal acceleration sensor and / or the calculated inclination can then be corrected on the basis of the plausibility check.

The control device according to the invention is defined in claim 12.

• 1 ein Diagramm zur Verdeutlichung des Verfahrens zur Ermittlung einer Neigung eines Fahrzeugs in Fahrtrichtung.

Preferred developments emerge from the subclaims and the following description. Embodiments of the invention will be described, without being limited thereto, with reference to the drawings. Showing:

• 1 a diagram illustrating the method for determining a slope of a vehicle in the direction of travel.

The invention relates to a method and a control device for determining an inclination of a vehicle in the direction of travel and a control device for carrying out the method.

In the method according to the invention for determining the inclination of a vehicle in the direction of travel, the inclination of the vehicle in the direction of travel is calculated on the basis of data on a longitudinal acceleration of the motor vehicle. For this purpose, a longitudinal acceleration sensor is installed in the vehicle, which provides data on the longitudinal acceleration of the motor vehicle as measured values, on the basis of which the inclination of the motor vehicle in the direction of travel can be calculated in a manner known per se.

Depending on the calculated inclination and a traveled distance, a first height change of the vehicle along the traveled distance and / or a first absolute height at least one point of the route is calculated.

Depending on an ambient air pressure provided by an air pressure sensor installed in the vehicle and / or a change in the ambient air pressure along the covered travel distance, a second altitude change of the traveled distance and / or a second absolute altitude at the or each point of the travel distance is calculated which also calculates the first absolute altitude.

To check the plausibility of the calculated inclination, namely the inclination of the vehicle in the direction of travel calculated on the basis of the longitudinal acceleration signal, a comparison now takes place between the first height change and the second height change and / or a comparison between the first absolute height and the corresponding second absolute height. A second absolute altitude corresponding to a first absolute altitude shall be understood to mean that altitude calculated in each case for the same point of the driving route.

Then, if a comparison between the first height change and the second height change and / or a deviation between the first absolute height and the corresponding second absolute height is determined, which is smaller than a defined limit is determined on a plausibly calculated inclination of Motor vehicle in the direction of travel, depending on the longitudinal acceleration closed. On the other hand, if the deviation between the first height change and the second height change and / or the deviation between the first absolute height and the corresponding second absolute height is greater than the limit value, then a non-plausibly calculated inclination of the vehicle in the direction of travel is assumed.

Then, when a non-plausibly calculated inclination of the motor vehicle in the direction of travel is detected, an error message is generated and / or a warning message perceptible to the driver initiating a workshop visit.

wobei

p(h0)

der Luftdruck zu Beginn der zurückzulegenden Fahrstrecke an der absoluten Höhe h0 zu Beginn der zurückzulegenden Fahrstrecke ist,

p(h1)

der Luftdruck zu Ende der zurückzulegenden Fahrstrecke an der absoluten Höhe h1 zu Ende der zurückzulegenden Fahrstrecke ist,

T(h0)

die Temperatur zu Beginn der zurückzulegenden Fahrstrecke an der absoluten Höhe h0 zu Beginn der zurückzulegenden Fahrstrecke ist ist, und

Δh

die zweite Höhenänderung h1-h0 ist.

The calculation of the altitude change based on the ambient air pressure is preferably carried out using the following barometric altitude formula: $$p\left(H1\right)=p\left(H0\right)*{\left(1-\frac{0.0065*\mathrm{\Delta }H}{T\left(H0\right)}\right)}^{5.255}$$

in which

p (h0)

the air pressure at the beginning of the route to be covered is at the absolute height h0 at the beginning of the route to be covered,

p (h1)

the air pressure at the end of the route to be covered is at the absolute height h1 at the end of the route to be covered,

T (h0)

the temperature at the beginning of the route to be covered is at the absolute height h0 at the beginning of the route to be covered, and

.delta.h

the second altitude change is h1-h0.

Based on the deviation between the first altitude change and the second altitude change and / or based on the deviation between the first absolute altitude and the corresponding second absolute altitude, it is possible to correct the signal of a longitudinal acceleration sensor and / or correct the calculated slope.

Further details of the invention are described below with reference to the diagram of 1 described, in 1 over a traveled distance s an absolute height h is plotted. The curve 1 of the 1 visualizes an absolute altitude calculated on the basis of an ambient air pressure provided by an air pressure sensor of the vehicle, whereas the curve 2 visualizes an absolute altitude, which is calculated on the basis of the calculated inclination and the traveled distance of the motor vehicle.

During the driving of the motor vehicle, a height of the vehicle is continuously calculated from the ambient air pressure provided by the air pressure sensor, wherein at the distance position s0 at the beginning of a calculation interval which extends between the distance positions s0 and s1, the current height h0 calculated at the distance position s0 as the reference altitude h _{REF is} stored.

Starting with the distance position s0, using the reference height determined at the distance position s0, h _{REF is determined} according to the curve 1 the height change continuously determined depending on the ambient air pressure.

Furthermore, according to the curve 2 the height change depending on the inclination of the motor vehicle, which is pending from the longitudinal acceleration, and depending on the distance traveled s continuously determined.

From the reference height h _REF and the respective height change, a respective absolute height can be determined, namely with respect to the height change depending on the ambient air pressure and with respect to the longitudinal acceleration dependent on the height change.

In the embodiment of 1 becomes the altitude calculated according to the ambient air pressure according to the curve 1 a tolerance band is set, which is defined by an upper limit 3 and a lower limit 4 is marked. The upper limit 3 and the lower limit 4 are at a given offset from the calculated curve 1 spaced.

Then, if the curve 2 , ie the height calculated on the basis of the calculated inclination and the traveled distance, within the tolerance band, which is defined by the upper limit 3 and the lower limit 4 is determined to the curve 1 is located, it is concluded on a plausible calculation of the inclination of the vehicle in the direction of travel.

In 1 ends at the route position s1 the predetermined calculation interval Δs. At the route position s1 the plausibility check is reset and restarted. At the route position s1 Accordingly, a new calculation or plausibility interval Δs begins.

As already stated, the plausibility check can be restarted not only after covering a defined route, but also when a defined period of time has expired and / or when wheel slip has been detected on the wheels of the vehicle.

The course of maximum value 3 and minimum value 4 of the tolerance band within the at the Wegstreckenposition s1 following new Plausibilisierungsintervalls can be seen that at constant curve 1 with Increasing distance increases the tolerance band.

The limit value for the plausibility check is therefore preferably determined as a function of the length of the traveled route, in such a way that a greater deviation is tolerated as the distance traveled increases than at the beginning of the route.

The curve 2 leaves at the route position s2 that around the curve 1 clamped tolerance band, so at the distance position s2 a non-plausible tilt is detected.

As already stated, when a non-plausible inclination of the vehicle in the direction of travel is detected, an error message and preferably also a warning message is generated, for example in the form of a flashing warning lamp or an information text in the display, to initiate a workshop visit.

Then, if the height calculated as a function of the inclination of the vehicle in the direction of travel and the distance traveled exceeds the height calculated as a function of the air pressure, a corrective offset can be added to the longitudinal acceleration signal of the longitudinal acceleration sensor. Such a correction of the calculation of the slope value is preferably carried out in the sense of an adaptation in small steps and is stored so that the corrected value is available again, for example after a restart.

The invention further relates to a control device or a control device which executes the method described above on the control side. This control unit is in particular an electronic transmission control unit.

The controller calculates an incline based on longitudinal acceleration data of the vehicle. The controller plausibility of the calculated inclination depending on an ambient air pressure and / or a change in the ambient air pressure.

Depending on a calculated inclination and the traveled distance, the control unit preferably calculates the first height change along the traveled route and / or the first absolute altitude at at least one point of the route.

Depending on the ambient air pressure and / or the change in the ambient air pressure along the traveled route, the controller calculates the second altitude change along the traveled distance and / or the second absolute altitude at the or each point of the route on which the first absolute altitude is calculated.

Depending on the comparison between the height changes or corresponding absolute heights, the control unit plausibility of the inclination of the vehicle in the direction of travel.

1

Kurvenverlauf erste Höhe/Höhenänderung

2

Kurvenverlauf zweite Höhe/Höhenänderung

3

oberer Grenze

4

unterer Grenze

reference numeral

1

Curve first height / height change

2

Curve course second altitude / altitude change

3

upper limit

4

lower limit

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

• DE 102010041967 A1 [0002]
• DE 102013213291 A1 [0003]
• DE 19939938 A1 [0004]

Claims (14)

A method for determining an inclination of a vehicle in the direction of travel, wherein an inclination of the vehicle in the direction of travel is calculated based on data on a longitudinal acceleration of the vehicle, characterized in that the calculated inclination is plausibility dependent on an ambient air pressure and / or a change in the ambient air pressure. Method according to Claim 1 , characterized in that depending on the calculated inclination and a traveled distance, a first change in altitude along the traveled distance is calculated, depending on the ambient air pressure and / or the change of the ambient air pressure along the traveled distance a second height change along the traveled distance is calculated, depending on a comparison between the first height change and the second height change, the calculated inclination of the vehicle in the direction of travel is plausibility. Method according to Claim 1 or 2 characterized in that, depending on the calculated inclination and a traveled distance, a first absolute altitude at at least one point of the route is calculated, depending on the ambient air pressure and / or the change of the ambient air pressure along the traveled distance, a second absolute altitude on or each point of the route on which the first absolute altitude is calculated is calculated, depending on a comparison between the first absolute altitude and a corresponding second absolute altitude, the calculated inclination of the vehicle in the direction of travel is plausibility. Method according to Claim 2 or 3 characterized in that, when the deviation between the first altitude change and the second altitude change and / or the deviation between the first absolute altitude and the corresponding second absolute altitude is less than a threshold, a plausibly calculated vehicle tilt in the direction of travel is concluded becomes. Method according to Claim 4 characterized in that, if the deviation between the first altitude change and the second altitude change and / or the deviation between the first absolute altitude and the corresponding second absolute altitude is greater than the threshold, then a non-plausibly calculated tilt of the vehicle in FIG Driving direction is closed. Method according to Claim 5 , characterized in that when a non-plausibly calculated inclination of the vehicle is closed in the direction of travel, generates an error message and / or a warning message is displayed. Method according to one of Claims 1 to 6 characterized in that a measurement signal of a longitudinal acceleration sensor is corrected based on the deviation between the first altitude change and the second altitude change and / or based on the deviation between the first absolute altitude and the corresponding second absolute altitude. Method according to one of Claims 1 to 7 characterized in that based on the deviation between the first altitude change and the second altitude change and / or based on the deviation between the first absolute altitude and the corresponding second absolute altitude the calculated tilt of the vehicle in the direction of travel is corrected. Method according to one of Claims 1 to 8th , characterized in that while driving depending on the ambient air pressure continuously a height of the vehicle is calculated at the beginning of a calculation interval, the current, calculated from the ambient air pressure altitude is stored in the subsequent calculation interval depending on the calculated slope and the distance covered the first Height change along the traveled distance and / or the first absolute height is calculated at least one point of the route, depending on the ambient air pressure and / or the change of the ambient air pressure along the traveled distance the second altitude change along the traveled distance and / or the second absolute height the or each point of the route on which the first absolute altitude is calculated, and depending on a comparison between the first altitude change and the second altitude change and / or depending on a comparison h between a first absolute height and a corresponding second absolute altitude, the calculated inclination of the vehicle in the direction of travel is made plausible. Method according to one of Claims 1 to 9 , characterized in that after a defined route and / or after a defined calculation period and / or upon detection of a wheel slip at the edges of the vehicle, the plausibility check is reset and restarted. Method according to one of Claims 4 to 10 , characterized in that the limit value for the comparison between the first altitude change and the second altitude change and / or for the comparison between a first absolute altitude and the second absolute altitude is determined depending on the length of the traveled route. Control unit (5) for a motor vehicle, wherein the control unit calculates an inclination of the vehicle in the direction of travel on the basis of data on a longitudinal acceleration of the vehicle, characterized in that the control unit (5) the calculated inclination depending on an ambient air pressure and / or a change of Ambient air pressure plausibility. Control unit (5) after Claim 12 characterized in that it calculates a first altitude change along a traveled distance and / or a first absolute altitude at at least one point of the route depending on the calculated inclination and the traveled distance, the same depending on the ambient air pressure and / or the change of the ambient air pressure along the traveled distance a second change in altitude along the distance traveled and / or a second absolute altitude at the or each point of the route on which the first absolute altitude is calculated calculated the same depending on the comparison between the first altitude change and the second altitude change and / or, depending on a comparison between a first absolute altitude and a corresponding second absolute altitude, the plausibility of the calculated inclination of the vehicle in the direction of travel. Control unit (5) after Claim 12 or 13 , characterized in that the control device (5) the method according to one of Claims 1 to 10 on the control side.

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