DE102019108111A1 - Assistance system for determining a vehicle mass using a linear estimator - Google Patents

Abstract

The invention relates to an assistance system (1) for a vehicle (2) with a drive unit (3) for determining a mass of the vehicle (2), the assistance system (1) having a computing unit (4), an acceleration sensor (5) and a wheel speed sensor (6) and the assistance system (1) is set up, a respective acceleration value (62a, 62b, 62z) determined with the acceleration sensor (5), a respective speed value (63a, 63b, 63z) determined with the aid of the wheel speed sensor for several different times Vehicle (2) and a respective value of a torque (64a, 64b, 64z) of the drive unit (3) in the form of respective first sensor data (61a, 61b, 61z), and the computing unit (4) is set up based on the respective first sensor data (61a, 61b, 61z) to calculate respective first value pairs (10a, 10b, 10z), each of the first value pairs (10a, 10b, 10z) having a first value (11a, 11b, 11z) and a second value ( 12a, 12b, 12z) and the respective first value (11a, 11b, 11z) corresponds to a respective argument of an estimation function and the respective second value (12a, 12b, 12z) corresponds to a respective function value of the estimation function, and based on the first value pairs (10a, 10b , 10z) to determine a first slope of the estimator, the mass essentially corresponding to the first slope.

Description

The invention relates to an assistance system for a vehicle and a method for determining a mass of the vehicle, a vehicle, a control device and a computer program product.

The DE 10 2014 200 557 A1 discloses a method for determining the vehicle mass of an electric vehicle or an electric hybrid vehicle. In the method, the motor torque of the electric motor, an acceleration of the vehicle and / or an angle of inclination of the vehicle is determined. In this method, the vehicle mass is determined using the engine torque, the acceleration and the angle of inclination.

The proposed assistance system for a vehicle with a drive unit is suitable for determining a mass of the vehicle and has a computing unit, an acceleration sensor and a wheel speed sensor. The assistance system is set up to record a respective acceleration value determined with the acceleration sensor, a respective speed value of the vehicle determined with the aid of the wheel speed sensor and a respective value of a torque of the drive unit in the form of respective first sensor data for several different points in time. The computing unit is set up to calculate respective first value pairs on the basis of the respective first sensor data. Each of the first value pairs has a first value and a second value, the respective first value corresponding to a respective argument of an estimator and the respective second value corresponding to a respective function value of the estimator. Furthermore, the computing unit is set up to determine a first slope of the estimator on the basis of the first value pairs, the mass essentially corresponding to the first slope.

Because the respective first value corresponds to the respective argument of the estimator and the respective second value corresponds to the respective function value, the mass can be determined directly in the form of the first slope of the estimator.

In other words, in the proposed assistance system, the mass can be determined as a value of a first parameter that describes the estimation function. The estimator is a linear function, i.e. can be represented as a straight line in a two-dimensional coordinate system with an abscissa and an ordinate. To determine the first slope, the computing unit preferably carries out a first, in particular linear, regression with the aid of the first value pairs.

Using the first regression, the arithmetic unit can determine the first slope of the estimator as the value of the first parameter and a distance from an intersection of the straight line with the abscissa or ordinate as a value of a second parameter for describing the estimator. The estimation function can be clearly determined with the aid of the values of the first and second parameters.

Determining the mass as the first slope of the estimator has the advantage that inaccuracies in the calculation of the respective first and second values of the first value pairs can at least partially or almost completely cancel each other out. As a result, one dimension of an error in determining the mass can be significantly reduced. The inaccuracies can arise, for example, from changing wind conditions, changing wheel slip of individual wheels of the vehicle or from inaccuracies in the intended simultaneous detection of the respective acceleration value, the speed value and / or the value of the torque.

The inaccuracies can partly or almost completely cancel each other out because the respective first value and the respective second value of the respective first value pair can be determined separately from one another and the arithmetic unit also preferably determines these separately from one another. The respective first and second values can be used separately from one another as input variables of the linear first regression, which means that the inaccuracies can be well compensated for. If an individual mass were to be determined directly as the quotient of the respective first and second value for each individual first value pair and the mass were formed as the mean value of the individual masses determined in this way, the inaccuracies could not be compensated so easily.

Furthermore, the mass can be read off directly from a diagram in which the estimation function is mapped. Another advantage is that the value of the second parameter can be used to assess the accuracy of the first regression carried out. If, for example, all first value pairs were to be recorded without an error, in particular the acceleration value and the value of the torque exactly, then the value of the second parameter would be zero. The more the value of the second parameter deviates from zero, the less precise the determination of the mass using the first regression.

The proposed method for calculating a mass of the vehicle comprises the following steps. The first step will be a respective acceleration value determined using the acceleration sensor, a respective speed value detected using the wheel speed sensor and a respective value of a torque of the drive unit for several different points in time in the form of respective first sensor data. In a second step, respective first value pairs are calculated using the respective first sensor data, each of the first value pairs having a first value and a second value and the respective first value corresponding to a respective argument of an estimator and the respective second value corresponding to a respective function value of the estimator.

In a third step, a first slope of the estimator is determined using the first value pairs, the mass essentially corresponding to the first slope. The first incline is preferably sent to a CAN bus in the vehicle. Analogously to the proposed assistance system, the advantages of the assistance system can be achieved when the method is carried out.

The proposed vehicle includes the assistance system. As a result, the same advantages can be achieved with the vehicle as with the assistance system.

The proposed control device is suitable for the vehicle and / or a vehicle component of the vehicle and is set up by the method and / or for carrying out the method.

The proposed computer program product causes a computer, when the computer program product is executed by the computer, to carry out the proposed method. The computer program product can be stored in the assistance system or, in a further variant, be present as a program on an external data carrier outside the vehicle. The computer is advantageously located in the assistance system and can be designed in the form of a microcontroller. Because the proposed method can be carried out on the computer with the aid of the computer product, it also has the advantages of the method or the proposed assistance system.

• 1 ein Fahrzeug mit einem Assistenzsystem mit einem Beschleunigungssensor, einer Recheneinheit und einem Raddrehzahlsensor,
• 2 erste Wertepaare zur Durchführung einer ersten Regression mit der Recheneinheit gemäß 1,
• 3 erste Sensordaten zur Berechnung der ersten Wertepaare gemäß 2,
• 4 die Recheneinheit gemäß 1,
• 5 zweite Wertepaare zur Durchführung einer zweiten Regression mit der Recheneinheit gemäß 1,
• 6 zweite Sensordaten zur Berechnung der zweiten Wertepaare gemäß 5,
• 7 die ersten Wertepaare gemäß 2 und eine mithilfe der ersten Regression bestimmte Schätzfunktion mit einer ersten Steigung.

The dependent claims describe further advantageous embodiments of the invention. Preferred exemplary embodiments are explained in more detail with reference to the following figures. They show schematically:

• 1 a vehicle with an assistance system with an acceleration sensor, a computing unit and a wheel speed sensor,
• 2 first value pairs for performing a first regression with the computing unit according to FIG 1 ,
• 3 first sensor data for calculating the first value pairs according to 2 ,
• 4th the arithmetic unit according to 1 ,
• 5 second value pairs for performing a second regression with the computing unit according to FIG 1 ,
• 6th second sensor data for calculating the second value pairs according to FIG 5 ,
• 7th the first value pairs according to 2 and an estimator with a first slope, determined using the first regression.

1 shows an assistance system 1 for a vehicle 2 with a drive unit 3 and a control unit 46 . The assistance system 1 has a computing unit 4th , an accelerometer 5 , a wheel speed sensor 6th and preferably a data connection 7th to the drive unit 3 on and is set up to a mass of the vehicle 2 to investigate. The arithmetic unit 4th can in the control unit 46 be integrated, which is not included in the 1 is shown. The assistance system 1 is set up with a respective one with the acceleration sensor for several different points in time 5 determined acceleration value 62a , 62b , 62z , each one using the wheel speed sensor 6th determined speed value 63a , 63b , 63z of the vehicle 2 and a respective value of a torque 64a , 64b , 64z the drive unit 3 , preferably over the data connection 7th , in the form of respective first sensor data 61a , 61b , 61z capture.

Furthermore, the arithmetic unit is 4th set up, based on the respective first sensor data 61a , 61b , 61z respective first value pairs 10a , 10b , 10z to calculate. Each of the first value pairs 10a , 10b , 10z has, as in 2 shown a first value 11a , 11b , 11z and a second value 12a , 12b , 12z , where the respective first value 11a , 11b , 11z a respective argument of an estimator and the respective second value 12a , 12b , 12z corresponds to a respective function value of the estimator. The arithmetic unit 4th is still set up based on the first value pairs 10a , 10b , 10z to determine a first slope of the estimator, wherein the mass corresponds essentially to the first slope.

wobei g die Erdbeschleunigung bezeichnet. Der jeweilige mit dem Beschleunigungssensor 5 ermittelte Beschleunigungswert ist jeweils bevorzugt der erste Beschleunigungswert α_x des Beschleunigungssensors 5, der zu dem entsprechenden Zeitpunkt von dem Beschleunigungssensor 5 ausgegeben wird.The accelerometer 5 is in the vehicle 2 built in and can preferably have a first acceleration value in an x-direction 41 is directed, and output a second acceleration value directed in a y-direction 42. The x direction 41 runs parallel to a vehicle longitudinal axis of the vehicle 2 and points in a direction in which the vehicle travels when traveling forward. The y-direction 42 points upwards perpendicular to the x-direction 41. The vehicle is located 2 at a standstill and stands on a roadway that assumes a positive angle α to the horizontal, as shown in 1 is shown, so gives the accelerometer 5 preferably a positive first acceleration value α _x which is directed in the x direction 41. The angle of the roadway α can generally be calculated as follows with the aid of the first acceleration value: $$\alpha =\text{arcsin}\left(\frac{a_x}{G}\right),$$

where g denotes the acceleration due to gravity. The one with the accelerometer 5 The determined acceleration value is in each case preferably the first acceleration value α _{x of} the acceleration sensor 5 at the appropriate time from the accelerometer 5 is issued.

The wheel speed sensor 6th can be designed as a physical sensor in a first variant. According to a second variant, the speed sensor is 6th designed in the form of a virtual sensor, which is preferably using a computer model in a further assistance system of the vehicle 2 such as an anti-lock braking system 45 or an ESP system 44 , can be simulated. For this purpose, the computer model can use values from several individual physical wheel speed sensors for the individual wheels of the vehicle 2 record and calculate to an averaged wheel speed value. The wheel speed sensor 6th preferably outputs the averaged wheel speed value and preferably forwards it via a CAN bus 82 of the vehicle 2 to the computing unit 4th continue. The advantage of calculating the wheel speed value as an averaged wheel speed value is that, when determining the averaged wheel speed value, respective positive and / or negative slip values of individual wheels can be taken into account. The slip values with different signs can arise in particular because a single wheel is a driving wheel or a traveling wheel of the vehicle 2 is.

With the help of a respective averaged wheel speed value recorded at the corresponding point in time and a dynamic radius of the wheels of the vehicle 2 can be the respective speed value of the vehicle 2 can be determined for the corresponding point in time. The arithmetic unit 4th can first store the averaged wheel speed values with the corresponding times and then calculate the corresponding speed values. It is also possible for one of the further assistance systems to calculate the respective speed value on the basis of the respective averaged wheel speed value and the dynamic radius and to use the CAN bus 82 to the computing unit.

The drive unit 3 is preferably an electric motor. The torque output by the electric motor fluctuates less over time than a torque output by an internal combustion engine. The smaller fluctuation enables the respective value of the torque of the drive unit 3 to be recorded more precisely at the different times. A control unit of the drive unit advantageously calculates 3 a current value of the torque of the drive unit 3 and transmits it over the data connection 7th to the assistance system 1 , especially to the computing unit 4th . It is also possible that the vehicle 2 in addition to the electric motor has an internal combustion engine and the drive unit 3 is designed in the form of a hybrid drive unit. In this case, the assistance system records 1 the first sensor data 61a , 61b , 61z preferred when the vehicle 2 is driven purely electrically with the help of the electric motor.

wobei n eine Anzahl aller ersten Wertepaare i , wie zum Beispiel die Wertepaare 10a, 10b bis 10z, x_i den jeweiligen ersten Wert i , wie zum Beispiel einer der ersten Werte 11a, 11b bis 11z, y_i den jeweiligen zweiten Wert i , wie zum Beispiel einer der zweiten Werte 12a, 12b bis 12z, x einen Mittelwert aller ersten Werte, y einen Mittelwert aller zweiten Werte bezeichnen. Die erste Steigung m₁ kann als ein erster Parameter der Schätzfunktion angesehen werden. Vorteilhafterweise berechnet das Regressionsmodul 33 einen Wert eines zweiten Parameters b zur Beschreibung der Schätzfunktion wie folgt: $$b=\overline{y}-m_1\cdot \overline{x}$$

Ist der Wert des zweiten Parameters kleiner oder gleich einer vorgegebenen ersten Schranke, so kann die Recheneinheit 4 die erste Steigung m₁ an einen Ausgang 81 der Recheneinheit 4 weiterleiten, wobei die erste Steigung m₁ im Wesentlichen der Masse des Fahrzeugs 2 entspricht. Die erste Schranke kann beispielsweise bei einem Prozent des Mittelwertes aller zweiten Werte liegen. Ist der Wert des zweiten Parameters b größer als die erste Schranke, so kann die Recheneinheit 4 die Masse derart bestimmen, dass die erste Steigung mit Hilfe des Wertes des zweiten Parameters b korrigiert wird. Eine Korrektur kann die Recheneinheit 4 wie folgt durchführen: $$m_{korr}=m_1+\frac{b}{\overline{x}}$$

The arithmetic unit 4th preferably has an in 4th shown regression module 33 with which based on the first value pairs 10a , 10b , 10z a first regression is feasible. The term "module" as used herein describes any hardware, software, firmware, artificial intelligence, fuzzy logic or combination of hardware and software that is able to carry out the functionality associated with the respective "module" . The regression module 33 can, according to a first variant, carry out the first regression in such a way that it calculates the first slope m ₁ as follows: $$m_1=\frac{{\displaystyle {\sum }_{i=1}^n\left[\left(x_i-\overline{x}\right)\cdot \left(y_i-\overline{y}\right)\right]}}{{\displaystyle {\sum }_{i=1}^n\left[{\left(x_i-\overline{x}\right)}^2\right]}},$$

where n is a number of all first value pairs i, such as the value pairs 10a , 10b to 10z , x _i the respective first value i, such as one of the first values 11a , 11b to 11z , y _i the respective second value i, such as one of the second values 12a , 12b to 12z , x an average of all first values, y denote an average of all the second values. The first slope m ₁ can be viewed as a first parameter of the estimator. The regression module advantageously calculates 33 one Value of a second parameter b to describe the estimator as follows: $$b=\overline{y}-{\mathrm{<figure-callout\; id="1"\; label="m"\; filenames="DE102019108111A1\_0025.png,DE102019108111A1\_0026.png"\; state="\{\{state\}\}">m</figure-callout>}}_1\cdot \overline{x}$$

If the value of the second parameter is less than or equal to a predetermined first limit, the computing unit can 4th the first slope m ₁ to an exit 81 the arithmetic unit 4th forward, the first slope m _{1 being} essentially the mass of the vehicle 2 corresponds. The first limit can be, for example, one percent of the mean value of all second values. If the value of the second parameter b is greater than the first limit, the computing unit can 4th determine the mass in such a way that the first slope is corrected with the aid of the value of the second parameter b. The arithmetic unit can make a correction 4th perform as follows: $$m_{kOrr}={\mathrm{<figure-callout\; id="1"\; label="m"\; filenames="DE102019108111A1\_0025.png,DE102019108111A1\_0026.png"\; state="\{\{state\}\}">m</figure-callout>}}_1+\frac{b}{\overline{x}}$$

When the correction is carried out, use is made of the fact that, in the event that the first sensor data were recorded without errors, the estimation function would have to be a straight line through the origin. The mass with the help of the first value pairs 10a , 10b , 10z , whose individual values correspond to arguments or function values of the linear estimator function, therefore offers the advantage of performing this correction. The computing unit _transmits a corrected first slope m _korr 4th to the exit 81 further after the computing unit 4th made the correction.

Furthermore, the value of the second parameter b can be used as a quality criterion for the first regression carried out. The more the value of the second parameter b deviates from 0, the less precise is the mass of the vehicle determined with the aid of the first regression 2 .

7th shows the first values 11a , 11b , 11z , the second values 12a , 12b , 12z and the estimator as shown in the form of a straight line 91 in a two-dimensional coordinate system with an abscissa 92 and an ordinate 93 is shown. The first slope can be based on a slope triangle 94 can be read. The value of the second parameter 95 , b, is on the ordinate 93 readable. Due to the simple graphic display of the determined vehicle mass 2 an accuracy in determining the mass can easily be checked.

wobei x_i,y_i entsprechend der erste Wert und der zweite Wert des jeweiligen ersten Wertepaares i ist.According to a second variant, the regression module 33 perform the first regression as follows: $$m_1=\frac{{\displaystyle {\sum }_{i=1}^n\left(y_i{x}_i\right)}}{{\displaystyle {\sum }_{i=1}^n{x}_i^2}},$$

where x _i , y _i are the first value and the second value of the respective first value pair i.

With the help of the assistance system 1 can the respective first sensor data 61a , 61b , 61z in a first storage element 8th , preferably in the form of respective first sensor data sets 61a , 61b , 61z , as it is saved in 3 is shown. A respective first sensor data set 61a , 61b , 61z can preferably be the acceleration value 62a , 62b , 62z , the speed value 63a , 63b , 63z and the respective value of the torque 64a , 64b , 64z and preferably have a point in time at which the corresponding sensor data record 61a , 61b , 61z is captured.

The respective first value pairs 10a , 10b , 10z differ in that their respective first or second value with the aid of the respectively different acceleration values 62a , 62b , 62z , different speed values 63a , 63b , 63z and different values of the torque 64a , 64b , 64z are calculated. The respective different acceleration values, different speed values and different values of the torque differ because they are obtained on the basis of the respective measurement data of the corresponding sensors, in particular on the basis of the respective first acceleration value, the respective averaged wheel speed value or the respective current value of the torque are recorded at the different times. Accordingly, the respective different first value pairs correspond 10a , 10b , 10z with the different times.

In a further development, the arithmetic unit is 4th set up as a function of at least one operating parameter of the vehicle 2 a current driving state of the vehicle 2 and, depending on the current driving condition, a respective type of calculation for calculating the first value 11a , 11b , 11z and second value 12a , 12b , 12z of the respective first value pair 10a , 10b , 10z perform. Furthermore is the arithmetic unit 4th set up according to this development, a wind resistance and a rolling resistance of the vehicle based on the respective calculation type 2 and to take into account a mass moment of inertia of at least one of the wheels of the vehicle. If the wind resistance, the rolling resistance and the mass moment of inertia of the wheels flow into the calculation of the first value pairs 10a , 10b , 10z with one, these first pairs of values can more precisely create an equilibrium of forces an acceleration process of the vehicle 2 depict.

A mass moment of inertia of all rotating masses that are operatively coupled to the wheels, referred to below as the total mass moment of inertia, is preferably also taken into account. The rotating masses preferably include a shaft, in particular a cardan shaft, with which at least two of the wheels are driven.

The arithmetic unit 4th recognizes the current driving state, preferably based on a first, second and third operating parameter of the vehicle 2 . The first operating parameter is a current angle of the roadway on which the vehicle is located 2 is located. The computing unit can determine the current angle α 4th for example when the vehicle is stationary 2 as described above. The second operating parameter is a current speed v of the vehicle 2 . The computing unit can determine the value of the second operating parameter 4th based on the last one with the help of the wheel speed sensor 6th determine the determined speed value. The third operating parameter is a current acceleration α of the vehicle 2 that is the arithmetic unit 4th also with the help of the wheel speed sensor 6th can capture. For this purpose, the computing unit 4th those from the wheel speed sensor 6th Derive the output values according to the time.

Using the first, second and third operating parameters, the computing unit can 4th recognize the current driving state preferably as a first, second, third, fourth, fifth, sixth, seventh or eighth driving state. Depending on whether the computing unit 4th recognizes the current driving state as the first, second, third, fourth, fifth, sixth, seventh or eighth driving state, executes the processing unit 4th a first, second, third, fourth, fifth, sixth, seventh or eighth type of calculation of the first value 11a , 11b , 11z and second value 12a , 12b , 12z by.

In the first driving state, the vehicle is running 2 forward up a mountain or on a plain and accelerate. In the second driving state, the vehicle is running 2 forward down a mountain and accelerate. In the third driving state, the vehicle is running 2 forward uphill or on a flat surface and decrease its speed. In the fourth driving state, the vehicle is running 2 forward down a mountain and slow down. In the fifth driving state, the vehicle is running 2 backwards down a hill or on a plain and increases its speed when reversing. In the sixth driving state, the vehicle is running 2 backwards up a hill and increases its speed when reversing. In the seventh driving state, the vehicle is running 2 backwards down a hill or on a plain and reduces its speed when reversing. In the eighth driving state, the vehicle travels 2 backwards up a hill and slows down when reversing.

Accelerates the vehicle 2 so the arithmetic unit can 4th the current angle of the roadway using the first acceleration value of the acceleration sensor 5 and a respective acceleration value α of the vehicle 2 determine as follows: $$\alpha =\text{arcsin}\left(\frac{a_x-a}{G}\right).$$

wobei α der jeweilige Beschleunigungswert des Fahrzeugs 2 ist, den die Recheneinheit 4 durch ein Ableiten der entsprechenden Geschwindigkeitswerte 63a, 63b, 63z berechnet, und f_R einen gesamten Rollwiderstandsbeiwert aller Räder des Fahrzeugs 2 bezeichnet. Weiterhin berechnet die Recheneinheit gemäß der ersten, zweiten, dritten und vierten Berechnungsart den zweiten Wert y_i des jeweiligen ersten Wertepaares i, wie zum Beispiel die zweiten Werte 12a, 12b, 12z, vorzugsweise wie folgt: $$y_i=\frac{M}{r}-\frac{J}{r^2}\cdot a-c_w\cdot A\cdot \frac{\rho }{2}\cdot v^2,$$

wobei M den jeweiligen Wert des Drehmomentes 64a, 64b, 64z, α den jeweiligen Beschleunigungswert des Fahrzeugs 2, v den jeweiligen Geschwindigkeitswert 63a, 63b, 63z, r einen dynamischen Radius eines Rades des Fahrzeugs 2, c_w einen Luftwiderstandsbeiwert des Fahrzeugs 2, A eine effektive Fläche des Fahrzeugs 2, die vertikal zur Fahrtrichtung ausgerichtet ist, J das Massenträgheitsmoment der Räder oder das gesamte Massenträgheitsmoment, und ρ eine Dichte der Luft bezeichnen.The arithmetic unit calculates according to the first, second, third and fourth types of calculation 4th the first value x _{i of} the respective first value pair i, such as the first values 11a , 11b , 11z , preferably as follows: $$x_i=a+G\text{sin}\alpha +G\cdot f_{\mathrm{R.}}\text{cos}\alpha \text{,}$$

where α is the respective acceleration value of the vehicle 2 is that the computing unit 4th by deriving the corresponding speed values 63a , 63b , 63z calculated, and f _R a total rolling resistance coefficient of all wheels of the vehicle 2 designated. Furthermore, according to the first, second, third and fourth type of calculation, the arithmetic unit calculates the second value y _{i of} the respective first value pair i, such as the second values 12a , 12b , 12z , preferably as follows: $$y_i=\frac{\mathrm{M.}}{r}-\frac{J}{r^2}\cdot a-c_w\cdot \mathrm{A.}\cdot \frac{\rho }{2}\cdot v^2,$$

where M is the respective value of the torque 64a , 64b , 64z , α the respective acceleration value of the vehicle 2 , v the respective speed value 63a , 63b , 63z , r is a dynamic radius of a wheel of the vehicle 2 , c _{w is} a drag coefficient of the vehicle 2 , A is an effective area of the vehicle 2 , which is aligned vertically to the direction of travel, J is the mass moment of inertia of the wheels or the total mass moment of inertia, and ρ denotes a density of the air.

und den zweiten Wert y_i des jeweiligen ersten Wertepaares i wie folgt: $$y_i=\frac{M}{r}-\frac{J}{r^2}\cdot a+c_w\cdot A\cdot \frac{\rho }{2}\cdot v^2.$$

The arithmetic unit calculates according to the fifth, sixth, seventh and eighth types of calculation 4th the first value x _{i of} the respective first value pair i preferably as follows: $$x_i=a+G\text{sin}\alpha -G\cdot f_{\mathrm{R.}}\text{cos}\alpha \text{,}$$

and the second value y _{i of} the respective first value pair i as follows: $$y_i=\frac{\mathrm{M.}}{r}-\frac{J}{r^2}\cdot a+c_w\cdot \mathrm{A.}\cdot \frac{\rho }{2}\cdot v^2.$$

Decreases the vehicle 2 the drive unit exercises its speed in the third, fourth, seventh and eighth driving conditions 3 preferably a braking torque on preferably two of the wheels. The value of the torque M is negative in this case. Alternatively it can be provided that the vehicle 2 is braked by the rolling resistance and the wind resistance and the value of the torque is zero when the vehicle 2 its speed decreased.

According to an advantageous embodiment, the assistance system 1 set up, analogous to the first sensor data 61a , 61b , 61z respective second sensor data 71a , 71b , 71z capture. The respective second sensor data 71a , 71b , 71z show how in 6th shown, analogous to the first sensor data 61a , 61b , 61z an acceleration value each 72a , 72b , 72z , a speed value 73a , 73b , 73z and a value of the torque 74a , 74b , 74z the drive unit 3 on. According to this embodiment, a first time span is within which the assistance system 1 the first sensor data 61a , 61b , 61z detected, greater than a second time span within which the assistance system 1 the second sensor data 71a , 71b , 71z detected. Furthermore, the first time period begins earlier than the second time period.

In the context of this embodiment, the arithmetic unit is 4th set up, respective second value pairs 20a , 20b , 20z based on the second sensor data 71a , 71b , 71z to calculate. The second value pairs 20a , 20b , 20z point analogously to the first value pairs 10a , 10b , 10z each a first value 21a , 21b , 21z and a second value 22a , 22b , 22z on how it is in 5 is shown. Furthermore, the arithmetic unit is 4th set up, based on the second value pairs 20a , 20b , 20z to determine a second slope of the estimator and to carry out a comparison between the first and the second slope and to correct the mass based on the comparison.

The computation unit advantageously calculates 4th the first and second values of the second value pairs analogous to the first and second values of the first value pairs. So can the computing unit 4th determine the first and second values of the second value pairs according to the first, second, third, fourth, fifth, sixth, seventh or eighth type of calculation, depending on whether the arithmetic unit 4th recognizes the current driving state as the first, second, third, fourth, fifth, sixth, seventh or eighth driving state.

wobei n eine Anzahl aller zweiten Wertepaare i , wie zum Beispiel die zweiten Wertepaare 20a, 20b bis 20z, x_i den jeweiligen ersten Wert i der zweiten Wertepaare, wie zum Beispiel einer der ersten Werte 21a, 21b bis 21z, y_i den jeweiligen zweiten Wert i der zweiten Wertepaare, wie zum Beispiel einer der zweiten Werte 22a, 22b bis 22z, x einen Mittelwert aller ersten Werte der zweiten Wertepaare, y einen Mittelwert aller zweiten Werte der zweiten Wertepaare bezeichnen. Vorteilhafterweise berechnet das Regressionsmodul 33 einen zweiten Wert des zweiten Parameters b wie folgt: $$b=\overline{y}-m_2\cdot \overline{x}.$$

The arithmetic unit 4th preferably performs a second regression using the regression engine 33 using the second value pairs 20a , 20b , 20z by. When the second regression is performed, the regression engine calculates 33 the second slope m ₂ advantageously analogous to the first slope as follows: $$m_2=\frac{{\displaystyle {\sum }_{i=1}^n\left[\left(x_i-\overline{x}\right)\cdot \left(y_i-\overline{y}\right)\right]}}{{\displaystyle {\sum }_{i=1}^n\left[{\left(x_i-\overline{x}\right)}^2\right]}},$$

where n is a number of all second value pairs i, such as the second value pairs 20a , 20b to 20z , x _i the respective first value i of the second value pairs, such as one of the first values 21a , 21b to 21z , y _i the respective second value i of the second value pairs, such as one of the second values 22a , 22b to 22z , x an average of all first values of the second value pairs, y denote a mean value of all second values of the second value pairs. The regression module advantageously calculates 33 a second value of the second parameter b as follows: $$b=\overline{y}-m_2\cdot \overline{x}.$$

Mithilfe des Assistenzsystems 1 können die jeweiligen zweiten Sensordaten 71a, 71b, 71z in einem zweiten Speicherelement 9, bevorzugt in Form jeweiliger zweiter Sensordatensätze 71a, 71b, 71z, gespeichert werden, wie es in 6 gezeigt ist.Analogously to the correction of the first slope, the computing unit 4th a corrected second slope m _{corr 2} calculate as follows: $$m_{kOr{r}_2}=m_2+\frac{b}{\overline{x}}.$$

With the help of the assistance system 1 can the respective second sensor data 71a , 71b , 71z in a second storage element 9 , preferably in the form of respective second sensor data sets 71a , 71b , 71z , as it is saved in 6th is shown.

The first and second storage elements 8th , 9 can be in the form of hardware or software. In the latter case, the storage elements 8th , 9 each be multi-dimensional fields with entries, with individual values of the first sensor data records in the fields 61a , 61b , 61z or second sensor data sets 71a , 71b , 71z can be stored. The arithmetic unit 4th can clear the fields while the vehicle is in operation 2 describe. The regression module is used to calculate the first and / or second value pairs 33 on the first storage element 8th or second storage element 9 and reads the in the corresponding memory element 8th , 9 stored first or second sensor data.

Because the first time span is greater than the second time span, the first regression can be used as a long-term estimation algorithm and the second regression as a short-term estimation algorithm, in each case for estimating the mass of the vehicle 2 be understood. The mass of the vehicle changes 2 not during the first time span, the mass determined with the aid of the first regression converges with the actual mass of the vehicle as the duration of the first time span increases 2 .

The arithmetic unit 4th preferably deletes or overwrites those in the second memory element 9 contained respective second value pairs at time intervals that are shorter than the first time span. For example, the first period of time can be an hour and the respective time segments in which the second memory element 9 deleted or overwritten, take 5 minutes. By deleting or overwriting the second memory element 9 the second regression can be restarted or corrected. In this way, corruption of comparatively old sensor data, such as the first sensor data, for example, can be avoided.

Furthermore, the computing unit 4th an abrupt change in the mass of the vehicle using the second regression 2 , for example when a person leaves the vehicle 2 exits or objects are loaded into the vehicle faster than with the first regression. Detects the computing unit 4th a sudden change in the mass of the vehicle 2 so the arithmetic unit can 4th the first value pairs in the first memory element 8th are also deleted. In order to recognize a sudden change in mass, the computing unit stores 4th the determined values of the second slope advantageously in the form of an auxiliary function as a function of the advancing time within the second time span. Furthermore, the computing unit 4th form a derivative of this auxiliary function and generate a signal as soon as the derivative of the auxiliary function is greater than a predetermined second limit.

The arithmetic unit calculates the comparison between the first slope and the second slope 4th preferably a difference between the first and the second slope. The abrupt change in mass can be made by the computing unit 4th detect according to a further variant based on the difference between the first and second slope.

If the difference is greater than a predefined third limit, the computing unit corrects it 4th preferably the mass. In this case, if the derivative of the auxiliary function is also greater than the second limit, the arithmetic unit gives 4th preferably the second slope or, in the event that a correction of the second slope is carried out, the corrected second slope m _{corr 2} at the exit 81 out. The computing unit can use the second slope or the corrected second slope 4th instead of the first or corrected first slope then also to the exit 81 forward if the second value of the second parameter b is below a predetermined fourth limit or if a number of all second value pairs 20a , 20b , 20z is greater than a given fifth limit.

The computing unit advantageously writes 4th the second sensor data 71a , 71b , 71z into the first storage element 8th , taking the first sensor data 61a , 61b , 61z deleted or overwritten if the derivative is greater than the specified second limit. As a result, the information on the basis of which the short-term estimation algorithm is carried out can be used for carrying out the long-term estimation algorithm.

In general, the first and the second storage element 8th , 9 function in such a way that as soon as a number of the first and second sensor data respectively reaches a predetermined number, the oldest first and second sensor data are deleted and replaced by the last recorded first and second sensor data. On the one hand, this allows the first and second regression to be carried out using the first and second sensor data that are as current as possible. On the other hand, this allows a size of a respective hardware memory required for the first or second memory element 8th , 9 be reduced. For example, the required hardware memory for the second storage element 9 designed, ie allocated, in such a way that it can only store in a range of up to about five to fifteen 32-bit floating point numbers.

A respective number of the first value pairs, the second value pairs, the first sensor data and the second sensor data can be between fifty and one thousand or less than 26, for example. The respective nomenclature a, b, z is not intended to be limiting.

Those calculated quantities that the arithmetic unit 4th to the exit 81 forwards, ie the first slope, the corrected first slope, the second slope or the corrected second slope, are from the output 81 to the CAN bus 82 Posted. Via the CAN bus 82 these variables are preferably all on the CAN bus 82 connected systems of the vehicle 2 available, such as the ESP system 44 or the anti-lock braking system 45 to a driver while driving the vehicle 2 can assist, or the control unit of the drive unit 3 . In this sense, assist the proposed assistance system 1 in particular the other assistance systems of the vehicle 2 . Can the control unit of the drive unit 3 the mass of the vehicle 2 in the form of the exit 81 sent first slope, corrected first slope, second slope or corrected second slope via the CAN bus 82 read in, so the control unit of the drive unit 3 an operating strategy of the drive unit 3 optimize more precisely based on the mass, in particular a range of the vehicle 2 approximate more precisely for purely electrical operation.

According to a development, the assistance system 1 a filter module 31 which is set up to filter the first sensor data and / or second sensor data as a function of at least one operating parameter or further operating parameters of the vehicle. The operating parameter and the further operating parameters can, for example, be the speed and / or the acceleration of the vehicle 2 each using the wheel speed sensor 6th can be determined, a pedal position of a brake pedal 43 or an accelerator pedal. The arithmetic unit can provide values of the operating parameters 4th in the form of a data record from the CAN bus 82 read out. The data record can advantageously be generated with the aid of one of the further assistance systems mentioned above and contain, for example, information as to whether the anti-lock braking system 45 or the ESP system 44 is activated.

The filter module 31 can filter the first and / or second sensor data, for example, in such a way that the first or second sensor data is only then transferred to the first memory element 8th or second storage element 9 are written when the operating parameter and / or the further operating parameters meet respective predetermined conditions. For example, it is possible that the filter module 31 the first and second sensor data only then to the storage elements 8th , 9 forwards when the brake pedal 43 is not pressed and the ESP system 44 and the anti-lock braking system 45 are not activated. Furthermore, the filter module 31 forwarding the first and second sensor data to the storage elements 8th , 9 block if a yaw rate is greater than a predetermined sixth barrier or a steering angle is greater than a predetermined seventh barrier or a slip value is greater than a predetermined eighth barrier. The yaw rate, the steering angle and the slip value are preferably contained in the data record.

The filtering of the first and second sensor data has the advantage that the first and second sensor data are mainly only then transferred to the first memory element 8th or second storage element 9 when the first and second sensor data are written with driving conditions of the vehicle 2 correspond in which the above-mentioned types of calculation have a comparatively high accuracy. For example, is the brake pedal 43 activated, this can be done by the control unit of the drive unit 3 calculated torque of the drive unit 3 do not act as a drive torque and therefore also do not cause an acceleration as can be calculated with the aid of the above-mentioned calculation types.

The filter module 31 forwards the first and second sensor data preferably only when the steering angle is approximately equal to zero, ie when the vehicle 2 drives straight ahead. The filter module also filters 31 the first and second sensor data are preferably included in the calculation of the respective first and second value pairs if the corresponding speed value is less than a specified ninth limit and the corresponding acceleration value is greater than a specified tenth limit.

In a further embodiment, the arithmetic unit is 4th , especially the filter module 31 , set up to synchronize the respective first and / or second sensor data. A synchronization of a respective first and / or second sensor data set can, for example, delay the with the acceleration sensor 5 determined acceleration value 62a compared to the speed value recorded with the wheel speed sensor 63a and with the control unit of the drive unit 3 recorded value of the torque 64a include. The synchronization can also filter high-frequency signal components from the acceleration sensor 5 Output signals to determine the acceleration value 62a include. With the help of synchronization, for example, signals from the acceleration sensor 5 even without using the CAN bus 82 using the arithmetic unit 4th are processed. In particular, the acceleration sensor 5 output the signals at a higher clock rate than the wheel speed sensor 6th .

In a further embodiment it is provided that the assistance system is an evaluation module 32 which is set up to evaluate the first sensor data and / or second sensor data, wherein a respective evaluation of the first or second sensor data is included in a calculation of the first value pairs or second value pairs.

The assessment module 32 preferably evaluates a respective temporal course of the operating parameters of the vehicle 2 , including preferably the first, second and / or third operating parameter. If the operating parameters have a fluctuation range below a predetermined eleventh If there is a limit, the evaluation module 32 weight the first and / or second sensor data higher than in a case in which the fluctuation range is above the eleventh limit. The evaluation module can add a weighting 32 for example, by putting the first or second sensor data multiple times in the first memory element 8th or second storage element 9 to be written. If the range of fluctuation is small, it can be assumed that external interfering influences fluctuate less when the first and second sensor data are recorded. In this case, the first and second sensor data can be more precise and cause a more precise calculation of the mass.

After the mass in the form of the first and / or second slope or corrected slope has been calculated as described above, the assistance system can 1 record new first and / or new second sensor data analogously to the first or second sensor data, hereinafter referred to as old first or old second sensor data. The filter module can 31 filter the new sensor data in the same way as the old sensor data. The regression module 33 can use the new first and second sensor data and the old sensor data to perform the first or second regression again and recalculate the first, second, corrected first and / or corrected second slope and thus the mass again and at the output 81 output.

The new first or second sensor data are preferably recorded at a higher rate than the first or second regression is carried out. This is particularly practical when the mass changes suddenly.

wobei der Zähler und der Nenner jeweils eine Umformung des oben aufgeführten Zählers und Nenners zur Berechnung der ersten Steigung darstellen. Bei der weiteren Berechnungsart können die Summen im Zähler und Nenner schneller neu berechnet werden, wenn die Recheneinheit 4 ein neues Wertepaar i + 1 mit einem neuen ersten Wert x_i+1 und einem neuen zweiten Wert y_i+1 anhand der neuen ersten Sensordaten berechnet hat. Hierzu speichert die Recheneinheit 4 folgende auf Basis der alten ersten Sensordaten ermittelte Werte in jeweiligen Zwischenspeichern der Recheneinheit 4: einen Wert eines ersten Terms des Zählers ${\displaystyle {\sum }_{i=1}^n{\text{x}}_{\text{i}}{\text{y}}_{\text{i}}}$

in einem ersten Zwischenspeicher 34, einen ersten Wert eines ersten Terms des Nenners ${\displaystyle {\sum }_{i=1}^n{\text{x}}_{\text{i}}^2}$

in einem zweiten Zwischenspeicher 35, den Mittelwert aller ersten Werte x in einem dritten Zwischenspeicher 36, den Mittelwert aller zweiten Werte y in einem vierten Zwischenspeicher 37 und eine Anzahl n an Wertepaaren in einem fünften Zwischenspeicher. Die Werte des ersten, zweiten, dritten und vierten Zwischenspeichers kann die Recheneinheit 4 mithilfe des neuen Wertepaares i + 1 wie folgt aktualisieren: $$\left|{\displaystyle \sum {\text{x}}_{\text{i}}{\text{y}}_{\text{i}}}\right|{}_{\text{i}+\text{1}}={\displaystyle \sum {\text{x}}_{\text{i}}{\text{y}}_{\text{i}}+x_{i+1}{y}_{i+1},}$$

$$\left|{\displaystyle \sum {\text{x}}_{\text{i}}^2}\right|{}_{\text{i+1}}={\displaystyle \sum {\text{x}}_{\text{i}}^2+{\text{x}}_{\text{i}+\text{1}}^2},$$

$$\left|\overline{\text{x}}\right|{}_{\text{i}+\text{1}}=\frac{\left(\overline{\text{x}}\cdot n+{\text{x}}_{i+1}\right)}{n+1},$$

$$\left|\overline{\text{y}}\right|{}_{\text{i}+\text{1}}=\frac{\left(\text{y}\cdot n+{\text{y}}_{i+1}\right)}{n+1}.$$

In order to be able to recalculate the mass as quickly as possible, the regression module 33 According to another calculation type, calculate the first slope as follows: $$m_1=\frac{{\displaystyle {\sum }_{i=1}^n{\text{x}}_{\text{i}}{\text{y}}_{\text{i}}-\text{n}\cdot \overline{\text{x}}\cdot \overline{\text{y}}}}{{{\displaystyle {\sum }_{i=1}^n{\text{x}}_{\text{i}}^2-\text{n}\cdot \overline{\text{x}}}}^2},$$

whereby the numerator and the denominator each represent a transformation of the numerator and denominator listed above for calculating the first slope. With the other type of calculation, the sums in the numerator and denominator can be recalculated more quickly if the arithmetic unit 4th has calculated a new value pair i + 1 with a new first value x _{i + 1} and a new second value y _{i + 1} based on the new first sensor data. For this purpose, the computing unit stores 4th the following values determined on the basis of the old first sensor data in the respective intermediate memories of the computing unit 4th : a value of a first term of the counter ${\displaystyle {\sum }_{i=1}^n{\text{x}}_{\text{i}}{\text{y}}_{\text{i}}}$

in a first buffer 34 , a first value of a first term of the denominator ${\displaystyle {\sum }_{i=1}^n{\text{x}}_{\text{i}}^2}$

in a second buffer 35 , the mean of all first values x in a third buffer 36 , the mean of all the second values y in a fourth buffer 37 and a number n of value pairs in a fifth buffer memory. The arithmetic unit can use the values of the first, second, third and fourth buffer memory 4th update using the new value pair i + 1 as follows: $$\left|{\displaystyle \sum {\text{x}}_{\text{i}}{\text{y}}_{\text{i}}}\right|{}_{\text{i}+\text{1}}={\displaystyle \sum {\text{x}}_{\text{i}}{\text{y}}_{\text{i}}+x_{i+1}{y}_{i+1},}$$

$$\left|{\displaystyle \sum {\text{x}}_{\text{i}}^2}\right|{}_{\text{i + 1}}={\displaystyle \sum {\text{x}}_{\text{i}}^2+{\text{x}}_{\text{i}+\text{1}}^2},$$

$$\left|\overline{\text{x}}\right|{}_{\text{i}+\text{1}}=\frac{\left(\overline{\text{x}}\cdot n+{\text{x}}_{i+1}\right)}{n+1},$$

$$\left|\overline{\text{y}}\right|{}_{\text{i}+\text{1}}=\frac{\left(\text{y}\cdot n+{\text{y}}_{i+1}\right)}{\mathrm{<figure-callout\; id="1"\; label="n\; +"\; filenames="DE102019108111A1\_0025.png,DE102019108111A1\_0026.png"\; state="\{\{state\}\}">n</figure-callout>}+1}.$$

The further type of calculation also makes it possible to dispense with intermediate storage of the first and second values of the value pairs that were calculated using the old first sensor data.

$${\left|{\displaystyle \sum {\text{x}}_{\text{i}}^2}\right|}_{\text{ i}+\text{1}}={\displaystyle \sum {\text{x}}_{\text{i}}^2+{\text{x}}_{\text{i}+\text{1}}^2}-{\text{x}}_1^2,$$

$${\left|\overline{\text{x}}\right|}_{\text{ i}+\text{1}}=\frac{\left(\overline{\text{x}}\cdot \text{n}+{\text{x}}_{i+1}-x_1\right)}{n},$$

$$\left|\overline{\text{y}}\right|{}_{\text{i}+\text{1}}=\frac{\left(\text{y}\cdot \text{n}+{\text{y}}_{i+1}-y_1\right)}{n}.$$

Regardless of this, the first value x ₁ and the second value y _{1 of} the oldest value pair can be replaced with the first value and the second value of the new value pair with little computational effort with the further type of calculation. The arithmetic unit can use the values of the first, second, third and fourth buffer memory 4th in this case update for example as follows: $$\left|{\displaystyle \sum {\text{x}}_{\text{i}}{\text{y}}_{\text{i}}}\right|{}_{\text{i}+1}={\displaystyle \sum {\text{x}}_{\text{i}}{\text{y}}_{\text{i}}}+x_{i+1}{y}_{i+1}-x_1{y}_1,$$

$${\left|{\displaystyle \sum {\text{x}}_{\text{i}}^2}\right|}_{\text{i}+\text{1}}={\displaystyle \sum {\text{x}}_{\text{i}}^2+{\text{x}}_{\text{i}+\text{1}}^2}-{\text{x}}_1^2,$$

$${\left|\overline{\text{x}}\right|}_{\text{i}+\text{1}}=\frac{\left(\overline{\text{x}}\cdot \text{n}+{\text{x}}_{i+1}-x_1\right)}{n},$$

$$\left|\overline{\text{y}}\right|{}_{\text{i}+\text{1}}=\frac{\left(\text{y}\cdot \text{n}+{\text{y}}_{i+1}-y_1\right)}{n}.$$

The arithmetic unit can do the other type of calculation 4th perform the same procedure when calculating the second slope. It is also possible that the computing unit 4th the first and second slopes determined on the basis of the first old sensor data or the second old sensor data with the help of the further calculation type.

QUOTES INCLUDED IN THE DESCRIPTION

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Patent literature cited

• DE 102014200557 A1 [0002]

Claims (10)

Assistance system (1) for a vehicle (2) with a drive unit (3) for determining a mass of the vehicle (2), the assistance system (1) having a computing unit (4), an acceleration sensor (5) and a wheel speed sensor (6) and the assistance system (1) is set up, for several different points in time, a respective acceleration value (62a, 62b, 62z) determined with the acceleration sensor (5), a respective speed value (63a, 63b, 63z) of the vehicle (2) determined with the aid of the wheel speed sensor and to detect a respective value of a torque (64a, 64b, 64z) of the drive unit (3) in the form of respective first sensor data (61a, 61b, 61z), and the computing unit (4) is set up based on the respective first sensor data (61a) , 61b, 61z) to calculate respective first value pairs (10a, 10b, 10z), each of the first value pairs (10a, 10b, 10z) having a first value (11a, 11b, 11z) and a second value (12a, 12b, 12z ) and the respective first value (11a, 11b, 11z) corresponds to a respective argument of an estimation function and the respective second value (12a, 12b, 12z) corresponds to a respective function value of the estimation function, and based on the first value pairs (10a, 10b, 10z) a first slope of the To determine the estimator, the mass essentially corresponding to the first slope. Assistance system (1) Claim 1 , the computing unit (4) being set up to recognize a current driving state of the vehicle (2) as a function of at least one operating parameter of the vehicle (2) and, as a function of the current driving state, a respective type of calculation for calculating the first value (11a, 11b, 11z ) and the second value (12a, 12b, 12z) of the respective first value pair (10a, 10b, 10z) and based on the respective type of calculation, a wind resistance and a rolling resistance of the vehicle (2) and a mass moment of inertia of at least the wheels of the vehicle (2) consider. Assistance system (1) Claim 1 or 2 , wherein the assistance system (1) is set up to record respective second sensor data (71a, 71b, 71z) in a manner analogous to the first sensor data (61a, 61b, 61z), with a first time span within which the assistance system (1) receives the first sensor data (61a, 61b, 61z) is greater than a second time span within which the assistance system (1) captures the second sensor data (71a, 71b, 71z) and begins earlier than the second time span, and the computing unit (4) is set up is to calculate respective second value pairs (20a, 20b, 20z) using the second sensor data (71a, 71b, 71z) and using the second value pairs (20a, 20b, 20z) to determine a second slope of the estimator and a comparison between the first Slope and the second slope and correct the mass based on the comparison. Assistance system (1) according to one of the preceding claims, wherein the assistance system (1) has a filter module (31) which is set up to use the first sensor data (61a, 61b, 61z) and / or as a function of at least one operating parameter of the vehicle (2) second sensor data (71a, 71b, 71z) to filter. Assistance system (1) according to one of the preceding claims, wherein the computing unit (4) is set up to synchronize the respective first sensor data (61a, 61b, 61z) and / or second sensor data (71a, 71b, 71z). Method for calculating a mass of a vehicle (2) with an assistance system (1) with the following steps: - Detection of a respective acceleration value (62a, 62b, 62z) determined with the aid of the acceleration sensor (5), a respective speed value (63a, 63b, 63z) detected with the aid of the wheel speed sensor and a respective value of a torque (64a, 64b, 64z) of the drive unit ( 3) for several different times in the form of respective first sensor data (61a, 61b, 61z) in a first step, - Calculation of respective first value pairs (10a, 10b, 10z) on the basis of the respective first sensor data (61a, 61b, 61z), each of the first value pairs (10a, 10b, 10z) having a first value (11a, 11b, 11z) and a second value (12a, 12b, 12z) and the respective first value (11a, 11b, 11z) corresponds to a respective argument of an estimation function and the respective second value (12a, 12b, 12z) corresponds to a respective function value of the estimation function, in a second step , - Determination of a first slope of the estimator on the basis of the first value pairs (10a, 10b, 10z), the mass essentially corresponding to the first slope. Procedure according to Claim 6 , whereby a wind resistance and a rolling resistance of the vehicle (2) and a mass moment of inertia of at least the wheels of the vehicle (2) are taken into account when calculating the respective first value pairs (10a, 10b, 10z). Vehicle (1) comprising an assistance system (1) according to one of the Claims 1 to 5 . Control unit (46) for a vehicle (1) and / or a vehicle component (44, 45), set up by a method and / or for carrying out a method according to one of the Claims 6 or 7th . A computer program product (10) comprising a program which, when executed by a computer, causes the computer to implement a method according to one of the Claims 6 or 7th perform.

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