Method for determining the loading state of a vehicle, vehicle and program product

Abstract

The presented invention relates to a method (100) for determining a loading state of a vehicle (200), wherein the method (100) comprises: - Determining (101) payload indicators, wherein the payload indicators describe at least a vehicle height (200), a vehicle roll angle (200) and a vehicle pitch angle (200), - Transferring (103) the payload indicators into a wheelbase vector using a predetermined wheelbase transfer function, wherein the wheelbase vector specifies a respective height for each wheel of the vehicle (200), - Determining (105) a wheel load vector - Determine (107) a distribution parameter that quantifies a distribution of the weight of a vehicle payload in the vehicle (200), - Output (109) of the distribution parameter on an output unit, with the distribution parameter being continuously updated.

Description

[0001] The presented invention relates to a method for determining a loading state of a vehicle, a vehicle and a program product according to the appended claims.

[0002] Motor vehicles are designed for a specified maximum load. Multi-track vehicles are also legally required to have a permissible total weight, which varies depending on the driver's license class.

[0003] In everyday use, the mass of a payload can usually only be estimated, which can result in unintended hazards due to component failure, as well as potential fines or penalties. The same problems exist with the maximum permissible nose weight of a trailer hitch.

[0004] The calculation of a vehicle's payload can be based, for example, on the chassis' height sensors. The problem with this is that it requires a fixed number of defined sensors, meaning the method cannot be transferred to another vehicle with a different sensor configuration. Another problem arises from the functionality of publicly available solutions, which make an assumption about the position of the load and thus do not fully capture the load status.

[0005] DE 10 2005 048 718 A1 describes a method and system for dynamically determining a vehicle load and a vertical load distance for use in a vehicle dynamics control system. The determination of the vehicle load is based on a lateral acceleration signal.

[0006] Within the scope of the presented invention, a method for determining a loading state of a vehicle, a vehicle and a program product are presented. Further features and details of the invention emerge from the respective subclaims, the description and the drawings. Features and details described in connection with the method according to the invention naturally also apply in connection with the vehicle according to the invention or the program product according to the invention and vice versa, so that with regard to the disclosure of the individual aspects of the invention, reference is or can always be made to each other. Against this background, it is an object of the presented invention to provide a possibility for determining a loading state of a vehicle.

[0007] Thus, according to a first aspect of the invention presented, a method for determining a loading state of a vehicle is presented.

[0008] The presented method comprises determining payload indicators, wherein the payload indicators describe at least a ride height of the vehicle, a roll angle of the vehicle and a pitch angle of the vehicle, transferring the payload indicators into a wheelbase vector by means of a predetermined wheelbase transfer function, wherein the wheelbase vector indicates a respective ride height for each wheel of the vehicle, determining a wheel load vector, determining a distribution characteristic value that quantifies a distribution of a weight of a payload of the vehicle in the vehicle and outputting the distribution characteristic value on an output unit, wherein the distribution characteristic value is continuously updated.

[0009] In the context of the present invention, a load indicator is understood to be a value determined using at least one sensor of a vehicle, which changes depending on the vehicle's load. In the context of the present invention, a distribution parameter is understood to be a value that quantifies a load position and / or an absolute size of a load. An example of a distribution parameter would be 10 kg / 98.1 N load; 456 mm as the X position; 123 mm as the Y position.

[0010] In the context of the present invention, outputting a distribution characteristic value means providing the distribution characteristic value on an output unit, such as a display or a memory, in particular an error memory. The distribution characteristic value can be provided, for example, in addition to a function that adjusts the vehicle depending on the distribution characteristic value.

[0011] The presented invention is based on the assumption that a difference in the distribution characteristic value caused by a particular load compared to a previous distribution characteristic value corresponds, in the sense of a force and moment equilibrium, to the difference in the selective wheel forces with respect to a previous measurement. Accordingly, based on the moment-free nature of the payload, a position of the payload at a selected level of the vehicle body can be determined.

[0012] Since the payload indicators provided according to the invention are based on a ride height of a respective vehicle, a roll angle of the vehicle and a pitch angle of the vehicle, i.e. are determined on the basis of respective measured values, these can be determined by various sensor configurations, so that there is no specific requirement for a large number of sensors in the vehicle, in particular no requirement for a ride height sensor per wheel.

[0013] Rather, the presented method enables the determination of a vehicle's load condition using, for example, a ride height sensor in the center of the vehicle's front axle, a pitch sensor, and a roll sensor. Alternatively, the ride height in the center of the front axle can be calculated based on values ​​determined by a number of other sensors, such as ride height sensors on the respective wheels of the front axle.

[0014] In particular, the payload indicators provided according to the invention can be combined to form a state vector.

[0015] According to the invention, the determined payload indicators are transformed into a wheelbase vector using a wheelbase transfer function, which specifies the respective height for each wheel of the vehicle. For this purpose, the wheelbase transfer function includes geometric information about the vehicle, such as its length, in particular its wheelbase, and its width.

[0016] Accordingly, it can be provided that the wheelbase transfer function includes information about a geometric characteristic, in particular a length and a width of the vehicle.

[0017] A wheel load vector is determined based on the wheelbase vector, for example by deriving the wheelbase vector several times over time.

[0018] As soon as the wheel load vector provided according to the invention is known, the distribution characteristic value provided according to the invention, which quantifies a distribution of a weight of a vehicle load in the vehicle, can be determined.

[0019] Accordingly, by outputting the distribution value on an output device, such as a display and / or a loudspeaker, a user can be informed about the distribution of a particular load on the vehicle. This means that a one-sided overload, for example, of a vehicle spring, can be detected and notified to the user. Alternatively or additionally, the user can be notified or displayed if the permissible total weight has been exceeded.

[0020] Furthermore, based on the distribution characteristic over time, a state of the vehicle, such as successive loading or coupling of a trailer, can be detected and output.

[0021] It may further be provided that the wheelbase transfer function includes values ​​of a wheel-selective spring characteristic curve.

[0022] By scanning a wheel-selective spring characteristic curve, i.e., by determining a position of a spring of a respective vehicle using, for example, a corresponding sensor, a static evaluation of the distribution characteristic value can be carried out, which statically describes a state of the vehicle's load.

[0023] It can further be provided that, in order to determine the wheel load vector, an applied force is determined for each wheel using a wheel load transfer function which includes values ​​of a damper characteristic curve and an inertia of a wheel suspension.

[0024] By sampling a damper characteristic curve, i.e., by determining a course of a movement of a damper by means of, for example, a corresponding sensor or by means of numerical differentiation of the wheelbases of the wheelbase vector, a dynamic evaluation of the distribution characteristic value can be carried out, which dynamically describes a state of a load of the vehicle on the basis of wheel-selective forces.

[0025] It can further be provided that the distribution characteristic value comprises a one-dimensional characteristic value that quantifies a distribution of the payload along a longitudinal axis, a transverse axis and / or a vertical axis of the vehicle. A one-dimensional indicator can simply and easily indicate the distribution of a load in a vehicle, for example, between a left and right side, or a front and rear. Alternatively or additionally, the distribution indicator can be displayed according to a color scheme, such as a traffic light system, so that a user can quickly and easily identify overloading.

[0026] It may also be provided that the distribution index is updated regularly, at a specified time interval.

[0027] By regularly updating the distribution index, a change in the distribution index over time can be determined, so that the condition of the vehicle can be inferred from the change in the distribution index, for example by identifying characteristic patterns in the course of the distribution index according to a predefined allocation scheme and assigning them to a respective condition.

[0028] It may further be provided that an optimization problem is formulated for values ​​determined by the respective available sensors with regard to an optimal force on the wheel suspensions of the vehicle or the smallest possible path deviation on the sensors used to detect the payload indicators in order to determine the payload indicators.

[0029] If the number of measured values ​​determined by the available sensors exceeds the number of payload indicators, the payload indicators are overdetermined. In this case, it can be provided that an optimization problem is solved that influences the determination of the payload indicators insofar as these are determined in a way that, when inferring the measured values ​​from the determined payload indicators, closely approximates the actually measured values ​​according to an error function. For example, a measurement on a vehicle with four ride height sensors on the four wheels of the vehicle leads to an overdetermination of the payload indicators, which can be taken into account by giving greater weight to the influence of a selected ride height sensor on one of the wheels. Likewise, e.g.An optimization problem aims to determine the payload indicators in a way that minimizes the mean square distance between the measured wheelbases and the wheelbases determined from them in the wheelbase vector. In particular, this optimization problem can also be solved with respect to force optimality using the determined wheel load vector.

[0030] It may further be provided that a current state of the vehicle is determined based on a course of the distribution characteristic value.

[0031] As soon as a characteristic pattern for a particular condition, such as a hitch-on process, appears in the distribution characteristic, the vehicle can be adjusted accordingly, for example, by switching a rearview camera and / or parking sensors to trailer operation. Furthermore, upon detection of this condition, the tongue load of the attached trailer can be determined.

[0032] It may also be provided that a warning message is issued if the distribution characteristic value is outside a permissible range.

[0033] A warning message, such as an alert on a display and / or a sound from a loudspeaker, quickly and easily signals to a user an inadmissible condition, such as overloading of the vehicle.

[0034] According to a second aspect, the presented invention relates to a vehicle. The presented vehicle comprises a plurality of sensors configured to determine values ​​that change depending on a vehicle's ride height, a vehicle's roll angle, and / or a vehicle's pitch angle, and a computing unit configured to execute a possible embodiment of the presented method.

[0035] In the context of the invention presented, a computing unit is understood to mean a computer, a processor, a control unit or any other programmable circuit.

[0036] According to a third aspect, the presented invention relates to a program product, wherein the program product comprises program code means that configure a computing unit to execute a possible embodiment of the presented method when the program product is executed on the computing unit.

[0037] Advantages that are described in detail for the method for determining a loading state of a vehicle according to the first aspect of the invention apply equally to the vehicle according to the second aspect of the invention and the program product according to the third aspect of the invention.

[0038] Further advantages, features, and details of the invention will become apparent from the following description, which describes embodiments of the invention in detail with reference to the drawings. The features mentioned in the claims and in the description may be essential to the invention individually or in any combination. They show: Fig. 1 a possible design of the presented procedure, Fig. 2 a possible design of the presented vehicle.

[0039] In Fig. 1 shows a sequence of the presented method 100 for determining a loading state of a vehicle.

[0040] The method 100 comprises a first determination step 101 in which payload indicators are determined based on measured values ​​determined by respective sensors of a respective vehicle, wherein the payload indicators comprise at least a ride height of the vehicle, a roll angle of the vehicle and a pitch angle of the vehicle.

[0041] The load indicators are determined based on measured values ​​determined by a number of sensors 201, 203, which change depending on a load on the vehicle, such as a position of a spring and / or a damper on a respective wheel and / or a position of a center section of a front axle of the vehicle.

[0042] The load indicators can, for example, be combined into a state vector that includes the ride height in the center of the front axle, the roll angle and the pitch angle.

[0043] Optionally, when determining the payload indicators, an optimization problem can be solved in the case that there is an overdetermination by the number of sensors 201, 203.

[0044] Furthermore, the method 100 comprises a transfer step 103 in which the payload indicators are transferred into a wheelbase vector by means of a predetermined wheelbase transfer function, wherein the wheelbase vector indicates a respective ride height for each wheel of the vehicle.

[0045] The relationship h = f(y) between height values ​​of the wheel-selective heights h and a status description of the vehicle y, e.g. via a transfer matrix H adapted to a vehicle geometry, results in h = Hy. The status description of the vehicle h can, for example, be a wheelbase vector over wheel-selective heights of all wheels of the vehicle.

[0046] In a second determination step 105, a wheel load vector is determined based on the wheelbase vector. For this purpose, the wheelbase vector is derived or differentiated several times over time to determine a velocity component and an acceleration component. For example, the wheel load vector can include a wheel load in the form of an applied force for each wheel of a respective vehicle.

[0047] For example, the wheel load vector can be determined using one or more time derivatives or by statistical methods, in particular as a force equilibrium based on the following relationships: ∑f=fVL+fVR+fHL+fHR+fz=0 and the moment equilibria ∑mx=t(fVL+fVR−fHL+fHR)+yzfz=0 and ∑my=−w(fHL+fHR)−yzfz=0

[0048] Furthermore, the method 100 comprises a determination step 107 in which a distribution characteristic value that quantifies a distribution of a weight of a payload of the vehicle in the vehicle is determined.

[0049] The distribution value can be determined, for example, based on the wheelbase vector and can be configured as a one-dimensional number. For example, the distribution value can be determined based on fz and additional position r. z in a vector x z , y z , with half track width t and wheelbase w.

[0050] Furthermore, the method 100 comprises an output step 109 in which the distribution characteristic value is output on an output unit, such as a display, a loudspeaker and / or a memory.

[0051] According to the method 100, it is provided that the distribution characteristic is continuously updated so that a dynamics of a change in the distribution characteristic can be evaluated in order to determine a state of the vehicle.

[0052] In Fig. 2, a vehicle 200 is shown. The vehicle 200 includes a plurality of sensors 201, 203 configured to determine values ​​that change depending on a change in a ride height of the vehicle 200, a roll angle of the vehicle 200, and / or a pitch angle of the vehicle 200.

[0053] Furthermore, the vehicle 200 comprises a computing unit 205 which is configured to carry out the method 100 according to Fig. 1 to execute. List of reference symbols 100 procedures 101 Determination step 103 Transfer step 105 Determination step 107 Investigation step 109 Output step 200 vehicles 201 Sensor 203 Sensor 205 computing unit QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2005 048 718 A1

[0005]

Claims

[1] Method (100) for determining a loading condition of a vehicle (200), the method (100) comprising: - determining (101) payload indicators, wherein the payload indicators describe at least a height of the vehicle (200), a roll angle of the vehicle (200) and a pitch angle of the vehicle (200), - transferring (103) the payload indicators into a wheelbase vector by means of a predetermined wheelbase transfer function, wherein the wheelbase vector indicates a respective height for each wheel of the vehicle (200), - determining (105) a wheel load vector, - determining (107) a distribution characteristic value which quantifies a distribution of a weight of a vehicle load in the vehicle (200), - outputting (109) the distribution characteristic value on an output unit, wherein the distribution characteristic value is continuously updated. [2] Method (100) according to claim 1, characterized bythat the wheelbase transfer function comprises information about a geometric characteristic, in particular a length and a width of the vehicle (200). [3] Method (100) according to claim 1 or 2, characterized by that the wheelbase transfer function includes values of a wheel-selective spring characteristic curve. [4] Method (100) according to one of the preceding claims, characterized by that in order to determine the wheel load vector, an applied force is determined for each wheel using a wheel load transfer function which includes values of a damper characteristic curve and an inertia of a wheel suspension. [5] Method (100) according to one of the preceding claims, characterized by that the distribution characteristic value comprises a one-dimensional characteristic number which quantifies a distribution of the payload along a longitudinal axis, a transverse axis and / or a vertical axis of the vehicle (200). [6] Method (100) according to one of the preceding claims, characterized bythat the distribution parameter is updated regularly, at a specified time interval. [7] Method (100) according to one of the preceding claims, characterized by that an optimization problem is formulated for values determined by respective available sensors (201, 203) with regard to an optimal force on the wheel suspensions of the vehicle (200) or the smallest possible path deviation on sensors (201, 203) used to detect the payload indicators in order to determine the payload indicators. [8] Method (100) according to one of the preceding claims, characterized by that a current state of the vehicle (200) is determined based on a course of the distribution characteristic value. [9] Method (100) according to one of the preceding claims, characterized by , a warning message is issued if the distribution parameter is outside a permissible range. [10] Vehicle (200), the vehicle (200) comprising: - a plurality of sensors (201, 203) configured to determine values that change as a function of a change in a ride height of the vehicle (200), a roll angle of the vehicle (200) and / or a pitch angle of the vehicle (200), - a computing unit (205), wherein the computing unit (205) is configured to execute a method (100) according to one of claims 1 to 9. [11] A program product, the program product comprising program code means that configure a computing unit to execute a method (100) according to any one of claims 1 to 9 when the program product is executed on the computing unit.

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