DE102004009417A1 - Vehicle inclination angle determination method in which the vehicle's height is measured in two positions, the separation between the positions is determined and the results combined to determine the longitudinal inclination - Google Patents

Abstract

Method for determining the inclination angle (alpha ) of a vehicle (210) in which height information is determined at two locations and from the information the physical height determined at these two locations. The separation (d) of the two locations is then determined and used with the height difference (delta H) between the two locations to determine the vehicle's longitudinal inclination angle. The invention also relates to a corresponding device for determining a vehicle's inclination angle.

Description

The The invention relates to a method and a device for determining a pitch angle of a vehicle.

In the vehicle technology are called HDC (Hill Descent Control), HSA (Hill Start Assistant), AVH (Active Vehicle Hold) and Hill Holder system facilities known to a vehicle a slope by an automatic actuation braking at standstill or at a constant speed stop and / or the driver when starting on a sloping road support. Use as input the control systems of these facilities the inclination angle of the roadway or the longitudinal tilt angle of the vehicle to a slope-compensating brake pressure to be able to determine.

Of the Inclination angle is in known methods by means of acceleration sensors determined, from the for a delay calculated by the vehicle brake pressure or by a Tilt sensor measured.

The Acceleration sensors make it possible determine the downhill acceleration a, determined by the relationship a = g sin (α) is linked to the inclination angle α, where g denotes the gravitational acceleration.

to Determination of the downhill acceleration of a moving Vehicle is a collection of measured values by at least two Acceleration sensors required because the slope acceleration as the difference between the total acceleration of the vehicle in its longitudinal direction and the longitudinal acceleration due to the angular acceleration of its wheels. So it will be at least one longitudinal acceleration sensor and a sensor is needed to detect the angular acceleration of the wheels.

The Method which determines the angle of inclination from acceleration values So, as well as the methods require those in which the angle of inclination is measured directly by a tilt sensor, a complex Sensors.

The Calculation of the angle of inclination from the applied for a deceleration of the vehicle Brake pressure can only be performed when the vehicle actually over a sufficient Delayed long distance becomes. The angle of inclination can thus only a certain period of time after reaching a gradient be recorded. The for a delay applied brake pressure hangs also from the coefficient of friction.

Further In-vehicle sensors are also used for this procedure the pitch angle needed so that even this procedure in case of failure or malfunction not performed by sensors can be.

moreover exists to increase Vehicle safety efforts, existing sensors redundant perform, or to check their measured values by plausibility tests.

Of the Invention is therefore the object of a provision of the To perform tilt angle of a vehicle with the least possible effort and even in the absence or failure of acceleration or Tilt sensors reliable make.

According to the invention this Problem solved by a method according to claim 1.

The Task is further by a device according to the claim 12 solved.

The The invention provides that a method for determining the angle of inclination of a vehicle is altitude information at a first and at a second location determined and physical heights from the determined height information be derived. There will be a height difference between the height of the first and the second place and a distance between them determined both places. Based on the height difference and the distance between the first and the second place is then a gradient between Both places corresponding inclination angle determined with the Tilt angle of the vehicle is identified.

It Thus, a method is provided that a determination the angle of inclination of a vehicle, without reference to measured values from acceleration or inclination sensors on the vehicle.

at Vehicles that are not equipped with such sensors, can the longitudinal inclination of the Vehicle using the method according to the invention with the help possibly existing systems are determined.

In the case of existing sensors, a sensor-independent longitudinal inclination angle determination could additionally be carried out and compared with the sensor-dependent determination. The on-board sensors, whose measured values are also used in particular as input variables for active driving safety systems, can be continuously monitored in this way by additionally determining this with the aid of the method according to the invention Longitudinal tilt angle is compared with the determined from the measured values of the sensors value of this angle. This is of particular safety-relevant interest, since the measured values of the sensors serve as input variables for active driving safety systems.

In a preferred embodiment the method according to the invention become the height information determined at a time offset. In this case, preferably first height information at a first place reached by a vehicle and then one height information at a second time reached by the vehicle at a later time Location determined. The slope Corresponding angles of inclination between the first and the second place reached then becomes the pitch angle of the vehicle identified at the second location.

In order to is for a moving vehicle is just a means of determining altitude information needed.

In a likewise preferred embodiment of the method the altitude information determined simultaneously at the first and at the second location, wherein the locations are preferably located inside the vehicle. at this implementation two means are required for determining altitude information.

It is furthermore preferred, the height information at the first and second locations using an altimeter to investigate.

In Another very advantageous embodiment of the method is It provided that received radio signals and the altitude information be determined by the radio signals.

there are preferably radio signals of a satellite navigation system receive. In particular, these are the radio signals of NAVSTAR GPS (Navigation System with Time and Ranging Global Positioning System) or GPS for short.

antennas for receiving GPS radio signals and receivers for their processing and evaluation are already available in many vehicles and will for the Position determination used by a navigation system.

at the method according to the invention can the altitude information the GPS advantageous for determining the pitch angle of a vehicle be used. The invention thus makes it possible already in continue to use existing systems.

In a further preferred embodiment is the satellite navigation system a differential one GPS (DGPS), which is a higher Accuracy in the location and height determination allows.

Generally It should be noted that despite the position error of GPS or DGPS, which are currently in a range of at least 1 to 2 meters, one quite accurate determination of altitude and position differences possible is. This is due to the fact that it is at the inaccuracies inducing influences um systematic influences which change only slightly with time and place.

The inventive method based exclusively on the determination of distances and height differences caused by systematic errors far less affected than absolute sizes, and thus allows a fairly accurate determination of the pitch angle.

The by GPS or DGPS directly supplied coordinates for one Location, so in particular the altitude information relate on an ellipsoidal frame of reference. That used by GPS and DGPS The coordinate system is currently based on the reference ellipsoid WGS84 (World Geodetic System 1984).

Out The GPS radio signals are thus purely geometric height information which does not agree with physical heights corresponding to the equipotential surfaces of the Gravity field of the earth are related.

For the determination the inclination angle of a vehicle, it is therefore particularly advantageous that determines physical heights from the ellipsoidal height information measured with the GPS which are given as orthometric heights or normal heights, for example become. These heights are related to a geoid or a quasigeoid.

It is in the implementation of the method thus particularly preferred that from the height information determined orthometric heights or normal heights for the first and for be derived from the second place.

Out the heights gained in this way of the first and second place, the gap between the first and second place and the inclination angle corresponding to this gradient determine if the distance between the two locations is known.

To determine the distance between In the case of a time-offset position determination, it is particularly advantageous for the two locations to be determined from the difference between the positions determined on the basis of the radio signals at the first and at the second location. However, it is also possible to determine the distance with the help of wheel speed sensors.

in the Case of simultaneous height determination with two mounted in the vehicle means for height determination the distance corresponds to the distance of the means and is thus known.

Of the the gradient between the first and the second place corresponding inclination angle α results from the relationship sin (α) = ΔH / d, where with ΔH the difference of the physical heights of the first and the second Place and d denotes the distance between the two places becomes.

By the invention also provides a device for determining the pitch angle created a vehicle. The device includes at least two antennas for receiving radio signals, means for determining the physical heights the antennas based on the radio signals, a means for calculating a Height difference between the antennas and a means for determining a slope corresponding Angle.

In a preferred embodiment If the antennas are antennas for receiving radio signals a satellite navigation system. The antennas are part of it a recipient for signals a satellite navigation system or connected to the receiver.

In an embodiment The devices have the antennas at vanishing pitch angle the same physical heights of the vehicle. This can cause the height difference especially easy at a non-zero inclination angle be determined.

Of the such particular pitch angle can serve to change vehicle parameters in its dependency.

So can be about the brake pressure in dependence the certain longitudinal inclinations adapted to the gradient become.

Of the determined by the method according to the invention Pitch angle can thus be used as an input for an HDC, HSA, AVH and / or advantageously Hill-holder system can be used.

It However, is also advantageous, the determined angle of inclination or the associated one Slope that To indicate driver of the vehicle by a display means.

This allows in particular, to warn the driver if the pitch angle exceeds a certain critical value.

moreover it is advantageous to determine the longitudinal inclination angle determined by the method according to the invention with one based on measurements of acceleration or others Sensors specific pitch angle compare to check the function of the sensors.

Further preferred embodiments emerge from the dependent claims and from the following description of preferred embodiments based on the figures.

From the figures shows

1 a schematic illustration of the relationship between ellipsoidal and physical height and

2 a schematic illustration of the determination of the longitudinal inclination of a vehicle from the specific sizes.

The present invention provides a novel and advantageous method with the longitudinal pitch angle α of a vehicle 210 can be determined.

In one implementation of the method, it is based on one of the vehicle 210 overcome height difference ΔH and a length d one of the vehicle 210 determined distance determined.

Another embodiment provides that the height difference ΔH and the distance d between two points P ₁ and P ₂ within the vehicle 210 be based on the procedure.

The overcome height difference ΔH and the distance traveled d are determined in a preferred embodiment of the method according to the invention by comparing the determined by means of a satellite navigation system positions P ₁ at the beginning and P ₂ at the end of the considered distance of length d.

However, it is also possible that at least the distance traveled d from measured values of wheel speed sensors of the vehicle 210 is determined. To determine the heights H ₁ and H ₂ at the first location P ₁ and the second location P ₂ can also be a conventional altimeter, at For example, a barometric altimeter, are used.

However, the determination by means of the satellite navigation system is preferred and makes it possible to carry out the method independently of measured values that are measured by sensors on the vehicle 210 to be delivered. Furthermore, the pitch angle a can potentially be determined with the greatest accuracy using a satellite navigation system.

In a very preferred embodiment of the method, the satellite navigation system GPS is used for determining the coordinates of the first location P ₁ and the second location P _2, and in particular for determining altitude information for the first location P ₁ and the second location P ₂ .

The following detailed Description of this implementation is to be understood only as an example and not restrictive. In particular, can the method also based on other navigation systems, such as based on the planned European Satellite navigation system GALILEO. Basically, though any device for determining height information into consideration.

The GPS contains at least 24 satellites, which cover the earth in one Height of about 20200 km during circumnavigate about 12 hours. The space segment of the GPS is designed in this way at least four satellites over one at any one time in any place on earth Elevation angles of at least 15 ° are "visible".

The Satellites permanently send two carrier waves in the L-band L1 and L2 with frequencies of 1575.42 MHz and 1227.60 MHz. Of the L1 carrier wave are two codes, the C / A (Coarse / Acquisition) code and the P (Precision) code, modulated, the L2 carrier wave contains only the P-code. The modulation frequency is 1.023 MHz for the C / A code and 10.23 MHz for the p-codes. The codes are pseudo-random codes with a 128 bit pattern.

The P-codes are encrypted, and their decryption is so far military recipients reserved, the higher Modulation frequency of the P-codes a higher accuracy in the position determination allowed to be achieved by the civilian C / A code can.

to Determining the position will be determined by a receiver's transit times of the satellite signals measuring the distance to the respective satellite is determined. The relative position of the receiver with respect to the satellites gives then on the distances to at least three satellites as the intersection of three spherical surfaces their respective radius corresponds to the distance to the corresponding satellite. Out the positions of the satellites known at all times with respect to the most basic reference systems let yourself the position of the recipient or its antenna with respect to of these systems.

The Runtime is calculated from the phase difference between in the Satellites and in the receiver synchronously generated pseudo-random code.

The accurate measurement of the transit time thus requires a precise synchronization of satellite and receiver clocks. The satellites have therefore about Synchronized, highly accurate and redundant atomic clocks. Especially from Cost and dimensioning reasons GPS receiver however equipped with simple quartz watches, which do not have the required accuracy.

Therefore be from the GPS receiver receive the signals from at least four satellites simultaneously and used for position determination. The four spherical surfaces whose Radii correspond to the distances to the four satellites, intersect only in exactly one point if each of the four distances is exactly determined. The receiver's clock can thus communicate with it the clocks of the satellites are synchronized, that the phase of the by his watch through the receiver generated codes until a clear position determination possible with four satellite signals.

In this way, a unique position of the receiver or the antenna ( 220 ) of the receiver, which can be given in coordinates of a suitable frame of reference.

The GPS uses an ellipsoidal reference system based on the reference ellipsoid WGS84 ( 110 ).

Thus, the height information h provided by the GPS gives the height of the receiver above the ellipsoid 110 and represent a purely geometric height information.

The ellipsoidal heights h have no relation to the gravitational field of the earth and from the difference the ellipsoidal heights h of two points can not say anything about the slope of one of these Derived points are resting objects.

The term inclination is doing in the übli It is understood that he indicates the position of an object with respect to the gravitational field of the earth. In particular, the longitudinal inclination of an object at a location means the angle between the longitudinal axis of this object and the equipotential surface of the gravitational field of the earth at that location.

The Presence of an inclination can, for example, with the help of a spirit level be determined, whereby the connection with the gravitational field of the Earth becomes particularly clear.

to Determination of longitudinal inclination of a vehicle, as carried out by the method according to the invention, Thus, a difference between physical heights H is needed, where under a physical height H to understand a related to the gravity field of the earth altitude information is.

In the method according to the invention, height information for a first location P ₁ and a second location P _{2 are} determined.

The ellipsoidal height information h for the first location P ₁ and the second location P ₂ must be converted into physical heights H given in a reference frame defined by the gravitational field of the earth.

Usually, these reference systems are based on the geoid 120 or the quasigeoid 130 ,

The relationship between ellipsoidal height h of a point P and physical heights H for this point P are given in FIG 1 illustrated.

It schematically shows a terrain section in which the surface of the reference ellipsoid 110 , the geoid 120 , the quasigeoid 130 , the earth's surface 140 and the sea surface 150 are drawn.

There are also the ellipsoidal height h, the orthometric height H _o and the normal height H _N sketched for the point P schematic table. Physical heights, ie in particular the orthometric height H _o and the normal height H _N , are summarized under the reference symbol H here.

The ellipsoidal height h of the point P results as the distance of the point P from the surface of the reference ellipsoid 110 , It comes directly from the GPS.

The geoid 120 is the equipotential surface of the Earth's gravity field through the middle sea surface 150 is formed with its continuation among the continents.

The distance between the geoid 120 and the reference ellipsoid 110 is called Geoidundulation N. The orthometric height H _o at the point P results from the length of the plumb line between the point P and the geoid 120 , Thus, the relationship h = H _o + N.

The quasigeoid is obtained by plotting the height anomalies ξ in the direction of the normal to the reference ellipsoid 110 above this ablates.

The normal height H _{N of} the point P results from the distance of the point P from the quasigeoid 130 thus given by the altitude anomaly ξ at the point P. It applies h = H N + ξ ,

The geoid and the quasigeoid result as a solution of the geodetic boundary value problem, which leads to Stoke's integral equation. The solution requires the exact knowledge of possible global datasets with height and gravity field information. Global gravity field models can be obtained from satellite observations. On the basis of these data already quite accurate local forms for the geoid could 120 and the quasigeoid 130 be determined.

The most accurate solution based on such observations for the European area the quasigeoid EGG97 (European Gravimetric Geoid 1997) of the institute for earth measurement the University Hannover, which in the area of the Federal Republic of Germany an accuracy from about 1 to 5 cm.

Another method for determining the geoid 120 and the quasigeoid is based on the GPS-leveling, for which points the exact physical height H is known, exact GPS measurements are made, and geoid and quasigeoid heights from the difference between the ellipsoidal height h given by the GPS and the physical height H be calculated. Here, the accuracy of the GPS measurement limits the accuracy of the solution. With the help of very complex procedures, accuracy in the sub-centimeter range can be achieved.

The difference between the orthometric height H _o and the normal height H _N is in the range of the accuracy of the geoid 120 or quasigeoids 130 ,

To carry out the method according to the invention for determining the longitudinal inclination angle α of a vehicle 210 in which a physical height H at a first location P ₁ and at a second location P _{2 is} determined, it is thus particularly advantageous that the vehicle 210 with a GPS receiver with at least one antenna 220 equipped and has a storage means in which the geoid 120 and / or the quasigeoid 130 or the Geoidundulation N and / or the height anomaly ξ are stored.

Farther is the vehicle with a means of calculating the difference between the Geoidundulation N and / or the height anomaly ξ and the ellipsoidal height h equipped to determine a physical height H.

Of the GPS receiver should one possible exact position and height determination enable.

The Accuracy present used civilian GPS receiver for the autonomous navigation, i. the navigation alone due to the The signals received by the satellite are typically in the range from some 10 m. military Enable GPS receiver in autonomous operation, the positioning with an accuracy of a few meters.

sources of error When determining the position with the GPS, inaccuracies of the satellite and receiver watches. In addition, however, also occur ionospheric and tropospheric Propagation delays of satellite signals and multipath effects.

The ionospheric and tropospheric propagation delays result from the refractive index of the earth's atmosphere, the especially with the temperature and humidity varies. moreover depends on that Size of the propagation delay of the Elevation of the satellite, since the signals from satellites with low Elevation angle a longer one Way through the atmosphere return as signals from satellites with a high elevation angle.

multipath are based on reflections of the satellite signals on objects such as houses, water areas etc. on the earth's surface. You can go through the use of special antennas are suppressed.

The atmospheric influences can through eliminates the use of the so-called DGPS (Differential GPS) become. It uses a reference GPS receiver whose antenna is positioned in a location with very well known coordinates. Based on a comparison of the known position of the antenna of the receiver with for his Position determined GPS data will be for any time and for a certain amount Environment around the reference receiver Corrections for the GPS data is determined. These are sent to the nearby GPS receivers and used to correct the position.

With Help from the DGPS can currently reach an accuracy of 1 to 2 m become.

It is therefore particularly preferred that the vehicle 210 whose pitch angle α is to be determined is equipped with a DGPS receiver.

The errors in the GPS measurement are systematic measurement errors that change only slowly with time and place. The error in the determination of a height difference ΔH for two adjacent locations P ₁ and P ₂ by two measurements, which are performed only very slightly time-delayed, should thus be significantly more accurate than the absolute position and altitude determination with GPS.

The longitudinal inclination angle α of a vehicle 210 , which is determined by height differences ΔH and position differences d, can thus be determined with the help of the currently achieved accuracy of GPS and in particular of DGPS with sufficient accuracy.

A schematic representation that illustrates how the pitch angle α of a vehicle 210 from the determined height difference ΔH between the first location P ₁ and the second location P ₂ and the distance d between both locations P ₁ and P _{2 is} determined in the 2a and 2 B shown.

The inclination angle α corresponding to the gradient between the first location P ₁ and the second location P ₂ results from the height difference ΔH between the location P ₁ and the location P ₂ and the distance d between the locations P ₁ and P ₂ through the relationship sin (α) = ΔH / d

In carrying out the method according to the invention, the inclination angle α of the terrain with the longitudinal inclination angle α of the vehicle 210 identified.

The height difference ΔH between both locations P ₁ and P ₂ is determined by referring to the reference ellipsoid 110 related GPS altitude information h ₁ and h _{2 are determined} at the first location P ₁ and at the second location P ₂ and derived therefrom physical heights H ₁ and H ₂ for the first location P ₁ and the second location P ₂ . This is done, as explained above, based on the geoid or the quasigeoid. It then applies ΔH = H 2 - H 1 ,

If orthometric heights H _o are used, the height difference ΔH can be calculated from the ellipsoidal heights h ₁ and h ₂ and from the geoid noises N ₁ and N ₂ at the locations P ₁ and P ₂ from the relation ΔH = h ₂ -h ₁ - (N ₂ - N ₁ ).

If normal heights H _N are used, the height difference ΔH can be calculated from the ellipsoidal heights h ₁ and h ₂ and from the height anomalies ξ ₁ and ξ ₂ at the locations P ₁ and P ₂ from the relation ΔH = h ₂ -h ₁ - (ξ ₂ - ξ ₁ ).

In a preferred embodiment of the method, with the aid of the GPS receiver, first the coordinates of the location P ₁ and in particular the height H ₁ at the first of the in the moving vehicle 210 attached antenna 220 reached place P ₁ determined.

Reach the antenna 220 of the vehicle after a certain period of time P ₂ , the position and the physical height H _{2 is} determined there by means of the GPS receiver. This is in the 2a shown.

The distance d between the point P ₁ and the point P ₂ is preferably determined from the difference between the positions of these locations. The thus-determined "straight line" between both points P ₁ and P ₂ coincides with the actual distance d if the two points P ₁ and P _{2 are} not too far apart.

It However, it is also conceivable that the distance d based on the measured values determined by wheel speed sensors. This is especially true advantageous if the height information is not using a satellite navigation system, but with the help of a conventional altimeter be determined. The distance determination can be based either the number of revolutions of the wheels while the time span between the two height measurements and the wheel circumference or based on the speed and the time span between the two measurements be determined.

The Measuring points should be in the case of GPS measurement as well as in case the conventional measurement are temporally and spatially close to each other, one as possible to achieve high accuracy in determining the pitch angle. she could for example, made at a distance of a few centimeters become.

In order to can also be in a terrain with frequent and steep slope changes, as they occur, for example off-road, the pitch angle of the vehicle be determined quite accurately.

In a terrain with weak gradient changes and often a constant gradient, as is for Traffic routes predominantly is present, is by a high number of measurement points, a regression allows which further enhances the accuracy of the process. So can at constant gradient for example, an average for determined at several locations longitudinal pitch angle α become.

It is particularly advantageous that the vehicle 210 has a means of dynamically deciding whether it is a terrain with a constant grade and a regression can be made, or whether it is a terrain with a slope change.

In a further preferred embodiment of the method according to the invention, the GPS measurements are made simultaneously at the first location P ₁ and at the second location P ₂ . This requires that the vehicle 210 via at least two GPS antennas 220 features.

The antennas 220 can each be connected to a receiving or evaluation device, or transmit signals to a common receiver.

This implementation is in the 2 B illustrated. The first location P ₁ and the second location P ₂ correspond to the positions of the first and the second GPS antenna 220 ,

The antennas 220 are preferably arranged so that an antenna 220 in a front area of the vehicle and another antenna 220 located in a rear area.

Furthermore, the antennas should 220 have the same physical height H at a vanishing inclination angle of α = 0. This allows a particularly simple determination of the height difference .DELTA.H to be determined.

This embodiment has the advantage that the distance d between the first location P ₁ and the second location P _{2 is} a vehicle parameter. It only has to be determined once and is then known with very high accuracy.

From the GPS measurements, only the height information H ₁ and H ₂ must be determined in this embodiment, so that the height difference ΔH is the only error-prone variable that enters into the determination of the longitudinal tilt angle α.

The simultaneous determination of the two heights H ₁ and H ₂ also has the advantage that they too For steep incline changes an exact value for the inclination angle α results.

at constant gradient can also in this implementation a regression performed to increase the accuracy of the procedure.

It is also possible here conventional altimeter in place of GPS receiver use.

The Use of GPS receivers However, it is preferred because it potentially provides higher accuracy for the process enable.

This This is especially the case because of the accuracy Positioning using satellite navigation systems continue to increase in the future becomes.

To the launch of the planned European satellite navigation system GALILEO does this through a combination of GALILEO and GPS data possible.

Next the GPS is in other embodiments also possible, other radio-based positioning systems use. Such systems are for example in mobile technology known. The accuracy of the positioning currently in However, GSM networks can be achieved, but is not enough. The Introduction However, the UMTS technology is already a higher accuracy in positioning enable.

The Position determination in mobile technology is based on the opposite to the positioning with satellite navigation systems on that the position of a transmitter in relation to several receiving stations is determined. The position can not be at the location of the transmitter be determined and must therefore be transmitted there. In addition to one Transmitter needed the vehicle in this embodiment The invention therefore a receiver for receiving the determined position.

Of the by the method according to the invention certain pitch angle α can be used to change vehicle parameters in their dependency.

Of the Pitch angle For example, it can be used as input for HDC control.

This will be in vehicles 210 used to compensate for the downgrade on a downhill slope. The brake pressure at the wheel brakes of the vehicle 210 is controlled by the HDC control by a compensation brake pressure according to the longitudinal inclination of the roadway or the vehicle 210 increases, depending on the pitch angle α of the vehicle 210 is determined.

The HDC control typically comes into effect when the increase the inclination angle d (sin (α)) / dt exceeds a predetermined threshold and / or the vehicle speed exceeds one exceeded by the driver to be specified threshold.

The longitudinal inclination angle α determined by the method according to the invention can likewise serve as an input variable for HSA of the hill holder systems. The HSA system assists the driver in starting on a downhill slope, while the Hill Holder system stops the vehicle 210 on a downgrade automatically effected.

In a further embodiment can the value of the determined by the method according to the invention pitch angle α with the Value to be compared, based on the measurements of vehicle sensors is determined. This allows to check the vehicle sensors.

Especially in view of the fact that the measurements of the vehicle sensors as Input variables in active Enter driving safety systems, this embodiment serves an increase the vehicle safety.

The present invention thus provides an advantageous method for determining the longitudinal inclination angle α of a vehicle 210 not available on onboard sensors of the vehicle 210 based. In a preferred embodiment, the longitudinal inclination angle α is thereby determined with the aid of GPS, which, in spite of its positional errors, permits an exact determination of the longitudinal inclination angle α.

110

reference ellipsoid

120

geoid

130

Quasigeoid

140

earth's surface

150

sea

210

vehicle

220

GPS receiver of the vehicle

α

Pitch angle

d

distance

AH

height difference

P

Point

P ₁

first place

P ₂

second place

H

ellipsoidal height

h ₁

ellipsoidal Height the first place

h ₂

ellipsoidal Height the second place

H

physical height

H ₁

physical Height of first place

H ₂

physical Height of second place

H _o

orthometric height

H _N

normal height

N

geoid undulation

ξ

height anomaly

Claims (14)

Method for determining the longitudinal inclination angle (α) of a vehicle ( 210 ), characterized in that a. height information (h ₁ , h ₂ ) is determined at a first location (P ₁ ) and at a second location (P ₂ ) and physical heights (H ₁ , H ₂ ) are derived from the ascertained altitude information (h ₁ , h ₂ ), b. a distance (d) between the first and second locations (P ₁ , P ₂ ) is determined, c. a height difference (ΔH) is obtained from the physical heights (H ₁ , H ₂ ) and d. on the basis of the height difference (ΔH) and the distance (d) between the first and the second location (P ₁ , P ₂ ) determines a slope angle (α) corresponding to a gradient between the two locations (P ₁ , P ₂ ) and with the longitudinal tilt angle ( α) of the vehicle ( 210 ) is identified. A method according to claim 1, characterized in that the height information (h ₁ , h ₂ ) are determined offset in time. Method according to one or both of Claims 1 and 2, characterized in that the inclination angle (α) corresponding to the gradient between the two locations (P ₁ , P ₂ ) is related to the longitudinal inclination angle (α) of the vehicle ( 210 ) is identified at the second location (P ₂ ). Method according to one or more of the preceding claims, characterized in that the height information (h ₁ , h ₂ ) are determined simultaneously. Method according to one or more of the preceding claims, characterized in that radio signals are received and the height information (h ₁ , h ₂ ) are determined on the basis of the radio signals. Method according to one or more of the preceding Claims, characterized in that radio signals of the NAVSTAR GPS are received. Method according to one or more of the preceding Claims, characterized in that radio signals of a differential GPS (DGPS) are received. Method according to one or more of the preceding claims, characterized in that orthometric heights (H _o ) and / or normal heights (H _N ) are derived from the height information (h ₁ , h ₂ ). Method according to one or more of the preceding claims, characterized in that the derivation of the physical heights (H, H _o , H _N ) by means of a Geoidundulation (N) and / or a height anomaly (ξ) is performed. Method according to one or more of the preceding claims, characterized in that the distance (d) between the first and the second location (P ₁ , P ₂ ) from the difference of the radio signals received at the locations (P ₁ , P ₂ ) determined positions is determined. Method according to one or more of the preceding claims, characterized in that the inclination angle (α) is determined from the relationship sin (α) = ΔH / d, where ΔH is the height difference between the physical heights (H ₁ , H ₂ ) and d Distance between the first location (P ₁ ) and the second location (P ₂ ). Device for determining the longitudinal inclination angle (α) of a vehicle ( 210 ) with a. at least two antennas ( 220 ) for receiving radio signals, b. a means for determining physical heights (H ₁ , H ₂ ) of the antennas ( 220 ) based on the radio signals, c. a means for calculating a height difference (ΔH) between the antennas ( 220 ) and d. a means for determining a slope between the antennas ( 220 ) corresponding angle (α). Device according to claim 12, characterized in that that they are antennas for receiving radio signals of a satellite navigation system is. Device according to one or both of Claims 12 and 13, characterized in that the antennas ( 220 ) have the same physical heights (H ₁ , H ₂ ) when the longitudinal inclination angle α = 0 disappears.