DE102018005239A1 - Method for a load test of a vehicle - Google Patents

Abstract

The invention relates to a method for carrying out a load test of a test vehicle (2), comprising the steps:
Providing (S1) a time profile of first load variables,
wherein the first load quantities are external influences and / or states of the reference vehicle (1) which are determined by measurement on a reference vehicle (1) when driving on a first route (11), the first route (11) being in a first area (21). is,
Determining (S2) a first load spectrum from the temporal course of the first load variables, the first load collective indicating a frequency and / or frequency and / or a height of respective first load variables,
Subdividing (S3) a second area (22) into passable route sections and assigning a respective time profile of expected second load variables to each of the route sections,
- combining (S4) the route sections of the second area (22) to a second route (12) such that a difference between a second load spectrum from the expected second load sizes and the first load spectrum is minimal among all possible combinations of route sections, and
- Driving or simulating (S5) a test drive of the second route (12) by the test vehicle (2) and detecting actual second load variables.

Description

The invention relates to a method for carrying out a load test of a test vehicle, a device for preparing a load test of a test vehicle, and a test vehicle with such a device.

The object of the invention is to carry out a load test on a test vehicle with easily definable boundary conditions on different test tracks.

The invention results from the features of the independent claims. Advantageous developments and refinements are the subject of the dependent claims.

• - Bereitstellen eines zeitlichen Verlaufs von ersten Belastungsgrößen, wobei die ersten Belastungsgrößen durch Messung ermittelte auf ein Referenzfahrzeug beim Befahren einer ersten Route wirkende äußere Einflüsse und/oder Zustände des Referenzfahrzeugs sind, wobei die erste Route sich in einem ersten Gebiet befindet,
• - Ermitteln eines ersten Lastkollektivs aus dem zeitlichen Verlauf der ersten Belastungsgrößen, wobei das erste Lastkollektiv eine Häufigkeit und/oder eine Frequenz und/oder eine Höhe von jeweiligen ersten Belastungsgrößen angibt,
• - Unterteilen eines zweiten Gebiets in befahrbare Routenabschnitte und Zuordnen eines jeweiligen zeitlichen Verlaufs von erwarteten zweiten Belastungsgrößen zu jedem der Routenabschnitte,
• - Kombinieren der Routenabschnitte des zweiten Gebiets zu einer zweiten Route derart, dass ein Unterschied zwischen einem zweiten Lastkollektiv aus den erwarteten zweiten Belastungsgrößen und dem ersten Lastkollektiv minimal unter allen möglichen Kombinationen von Routenabschnitten ist, und
• - Befahren oder Simulieren einer Befahrung der zweiten Route durch das Testfahrzeug und Erfassen von tatsächlichen zweiten Belastungsgrößen.

A first aspect of the invention relates to a method for carrying out a load test of a test vehicle, comprising the steps:

• Providing a time profile of first load variables, wherein the first load quantities are external influences and / or states of the reference vehicle determined by measurement on a reference vehicle when driving on a first route, the first route being located in a first area,
• Determining a first load spectrum from the temporal course of the first load variables, the first load collective indicating a frequency and / or a frequency and / or a height of respective first load variables,
• Subdividing a second area into passable route sections and assigning a respective time profile of expected second load variables to each of the route sections,
• Combining the route sections of the second area to a second route such that a difference between a second load spectrum from the expected second load sizes and the first load spectrum is minimal among all possible combinations of route sections, and
• - driving or simulating a driving of the second route through the test vehicle and detecting actual second load quantities.

The test vehicle and the reference vehicle may each be a car, truck or a bus.

The first area and the second area are preferably geographical regions within which route sections can be selected and combined to produce a respective route. In particular, the road sections are to be delimited from one another by intersections and junctions on a road network. Preferably, the route sections are combined in such a way that the route sections form a coherent respective route without gaps and without additional sections between each other. Preferably, the first region and the second region are geographically separated regions, and more preferably, the second region is a virtual region or virtual image of a real second region.

The first load collective and in particular also the second load collective respectively indicate a frequency and / or a frequency and / or a height of respective load variables. The height of the respective load quantities is preferably expressed in a numerical value which represents a measure of the intensity of the load size. The frequency of a respective load quantity gives a repetition rate of a respective load quantity, preferably together with the information as to which amount of the respective load quantity occurs in which frequency in total. In the case of an oscillatory load, a Fourier transformation is preferably used for this purpose. In particular, the frequency of a respective load variable describes the sum of all occurrences of a discrete load. The respective load collective is therefore to be understood in particular as an integral of load variables and their sorting and / or classification of the components of the integral.

It is an advantageous effect of the invention that for performing a load test of a vehicle easily definable boundary conditions for test tracks can be specified.

Preferably, the first route is composed of individual partial routes traveled by the reference vehicle.

Advantageously, a desired load spectrum from the measured first load variables can be compiled thereby, which is to be examined in the test vehicle by means of a load test.

Preferably, the test vehicle and the reference vehicle are of the same vehicle type, the vehicle type being colloquially referred to as "model". Two vehicles of a vehicle type have in particular the same engine, the same fuel source and gearboxes of the same specifications.

According to an advantageous embodiment, the first load quantities have at least one of the following sizes or combinations the following magnitudes: a torque at an engine output shaft of the reference vehicle, a torque at a driven wheel of the reference vehicle, an engine speed of an engine of the reference vehicle, a speed of the reference vehicle, a time distribution of the engaged gears of a shiftable transmission of the reference vehicle, wherein the second load quantities at least one of the following quantities: a torque at an engine output shaft of the test vehicle, a torque at a driven wheel of the test vehicle, an engine speed of an engine of the test vehicle, a speed of the test vehicle, a time distribution of the engaged gears of a switchable transmission of the test vehicle.

According to a further advantageous embodiment, the test vehicle and the reference vehicle are identical.

According to a further advantageous embodiment, the expected second load variables per route section of the second area are external influences and / or states of the reference vehicle or of the test vehicle which are determined by measurement on the reference vehicle or on the test vehicle when driving on the second route.

According to a further advantageous embodiment, the expected second load variables are determined from a virtual model of a test track for the test vehicle, as well as from at least one of the following elements: dynamic model of the test vehicle, engine characteristic of an engine of the test vehicle, shift characteristic of an automatic transmission of the test vehicle, mass of the test vehicle, Characteristics of wheels of the test vehicle, a dynamic driver model, an acceleration behavior of a driver from a dynamic driver model, a deceleration behavior of a driver from a dynamic driver model.

• - Ermitteln des Unterschieds zwischen dem aus den tatsächlichen zweiten Belastungsgrößen ermittelten zweiten Lastkollektiv und dem ersten Lastkollektiv nach dem Befahren oder Simulieren der Befahrung der zweiten Route durch das Testfahrzeug.

According to a further advantageous embodiment, the method further comprises the step:

• Determining the difference between the second load collective determined from the actual second load variables and the first load collective after driving on or simulating the driving of the second route through the test vehicle.

It is advantageous to make a statement by the known difference to what extent the test drive with the test vehicle has actually met the desired load spectrum, namely the first load collective.

According to a further advantageous embodiment, the combining of the route sections of the second area to the second route takes place such that the second route is a closed curve.

Advantageously, the starting point and the end point of a closed curve are identical, so that after the complete driving on the second route, the test vehicle again reaches its starting point.

According to a further advantageous embodiment, the combining of the route sections of the second area to a second route takes place such that the chronological course of the second load variables when driving on the second route is as similar as possible to the time profile of the first load variables.

By adjusting the temporal courses, temperature effects during operation as well as non-linear effects, hysteresis effects and other operating-time-dependent effects are advantageously taken into account.

• - eine erste Schnittstelle, die zum Bereitstellen eines zeitlichen Verlaufs von ersten Belastungsgrößen ausgeführt ist, wobei die ersten Belastungsgrößen durch Messung mittels einer Sensoreinheit ermittelte auf das Referenzfahrzeug beim Befahren einer ersten Route wirkende äußere Einflüsse und/oder Zustände des Referenzfahrzeugs sind, wobei die erste Route sich in einem ersten Gebiet befindet, und
• - eine Recheneinheit, die zum Ermitteln eines ersten Lastkollektivs aus dem zeitlichen Verlauf der ersten Belastungsgrößen ausgeführt ist, wobei das erste Lastkollektiv eine Häufigkeit und/oder Frequenz und/oder eine Höhe von jeweiligen Belastungsgrößen angibt, und die zum Unterteilen eines zweiten Gebiets in befahrbare Routenabschnitte und Zuordnen eines jeweiligen zeitlichen Verlaufs von erwarteten zweiten Belastungsgrößen zu jedem der Routenabschnitte ausgeführt ist, und die zum derartigen Kombinieren der Routenabschnitte des zweiten Gebiets zu einer zweiten Route ausgeführt ist, dass ein Unterschied zwischen einem zweiten Lastkollektiv aus den zweiten Belastungsgrößen und dem ersten Lastkollektiv minimal aus allen möglichen Kombinationen von Routenabschnitten ist.

Another aspect of the invention relates to an apparatus for preparing a load test of a test vehicle, comprising:

• a first interface which is designed to provide a chronological progression of first load variables, wherein the first load variables are external influences and / or states of the reference vehicle which are determined by measurement by means of a sensor unit and which affect the reference vehicle when driving on a first route, wherein the first route is in a first area, and
• - A computing unit, which is designed to determine a first load spectrum from the time course of the first load sizes, the first load collective indicating a frequency and / or frequency and / or height of respective load sizes, and for subdividing a second area into passable route sections and assigning a respective time history of expected second load quantities to each of the route sections, and which is configured to combine the route sections of the second area into a second route such that a difference between a second load spectrum from the second load sizes and the first load spectrum is minimum from all possible combinations of route sections.

Advantages and preferred developments of the proposed device are obtained by an analogous and analogous transmission of the statements made in connection with the proposed method above.

Another aspect of the invention relates to a test vehicle having a device as described above and below.

Further advantages, features and details will become apparent from the following description in which - where appropriate, with reference to the drawings - at least one embodiment is described in detail. The same, similar and / or functionally identical parts are provided with the same reference numerals.

• 1 ein Verfahren zum Durchführen eines Belastungstests eines Testfahrzeugs gemäß einem ersten Ausführungsbeispiel der Erfindung,
• 2 ein erstes Gebiet und ein zweites Gebiet gemäß dem Verfahren des ersten Ausführungsbeispiels der Erfindung, und
• 3 ein Testfahrzeug mit einer Vorrichtung zum Vorbereiten eines Belastungstests an dem Testfahrzeug gemäß einem weiteren Ausführungsbeispiel der Erfindung.

Show it:

• 1 a method of performing a load test of a test vehicle according to a first embodiment of the invention,
• 2 a first region and a second region according to the method of the first embodiment of the invention, and
• 3 a test vehicle with a device for preparing a load test on the test vehicle according to another embodiment of the invention.

The illustrations in the figures are schematic and not to scale.

1 shows a method for performing a load test of a test vehicle 2 , In a first step of the method, a provision is made S1 a time course of first load sizes, wherein the first load quantities determined by measurement on a reference vehicle 1 when driving on a first route 11 acting external influences and / or conditions of the reference vehicle 1 are. By contrast, the expected second load variables are determined by measurement on the reference vehicle 1 when driving on the second route 12 acting external influences and / or conditions of the reference vehicle 1 or the test vehicle 2 , The reference vehicle 1 At this time, it already has a reference trip via a first route 11 completed, and the measured data are thus available as a record. The first route 11 is located in a first area 21 , a low mountain range. In a second step, a determination is made S2 a first load spectrum from the temporal course of the first load variables, wherein the first load collective indicates a frequency of respective first load variables in a respective height, that is, it is determined as a first load spectrum, a record, in which frequency and at what absolute frequency a certain amplitude or amplitude range a respective one of the first load quantities during the entire test drive of the reference vehicle 1 over the first route 11 appeared. Furthermore, a subdivision takes place S3 a second area 22 into passable route sections and assigning a respective time profile of expected second load variables to each of the route sections. The second area 22 is a high mountain. The areas 21 . 22 are here with the respective vehicles 1 . 2 and the respective routes 11 . 12 in the 2 displayed. The expected course of second load variables is from the reference vehicle 1 already known that a plurality of route sections in the second area 22 has traveled in the past and also for this plurality of route sections a time course of the second load sizes for all traveled route sections of the second area 22 stores in order to later combine them arbitrarily, but preferably in a coherent manner. In a further step of the method, this is done and there is a combination S4 the route sections of the second area 22 to a second route 12 such that a difference between a second load spectrum from the second load quantities and the first load collective is minimal among all possible combinations of route sections. Thus, the route selection in the second area becomes 22 performed such that the first load collective and the second load collective are as similar as possible, and in the second area a second route 12 can be chosen such that the first load collective of the first route 10 in the first area 21 to replicate without going to the first area 21 to enter. The first load variables and the second load variables have the following parameters: A torque on a driven wheel of the reference vehicle 1 and the test vehicle 2 , an engine speed of an engine of the reference vehicle 1 and the test vehicle 2 , a speed of the reference vehicle 1 and the test vehicle 2 , and a temporal distribution of the engaged gears of a shiftable transmission of the reference vehicle 1 and the test vehicle 2 , It follows the driving S5 the second route 12 through the test vehicle 2 , which is of the same vehicle type as the reference vehicle 1 , Subsequently, a determination is made S6 the difference between the second load collective and the first load collective after driving on the second route 12 through the test vehicle 2 ,

2 shows a first area 21 and a second area 22 , The two areas 21 and 22 are geographically separated from each other and each have a road network, in each of which a plurality of route sections can be combined. The basically possible passable route sections are shown as dash-dot lines, the first route 11 and the second route 12 as solid lines. Incidentally, the description of the 1 for a better understanding of 2 be applied.

3 shows a test vehicle 2 with a device 100 for preparing a load test of the test vehicle 2 , The device 100 has a first interface 3 , which is designed to provide a time course of first load variables, wherein the first load quantities by measurement by means of a sensor unit 5 determined on the reference vehicle 1 when driving on a first route 11 acting external influences and / or conditions of the reference vehicle 1 are, taking the first route 11 in a first area 21 located. Furthermore, the device 100 an arithmetic unit 7 , which is designed to determine a first load spectrum from the time profile of the first load variables, the first load collective indicating a frequency and / or frequency and / or a height of respective load variables, and for dividing a second area 22 is executed in passable route sections and assigning a respective time course of expected second load sizes to each of the route sections, and for combining such the route sections of the second area 22 to a second route 12 is executed that a difference between a second load spectrum of the second load sizes and the first load spectrum is minimal from all possible combinations of route sections.

Although the invention has been further illustrated and explained in detail by way of preferred embodiments, the invention is not limited by the disclosed examples, and other variations can be derived therefrom by those skilled in the art without departing from the scope of the invention. It is therefore clear that a multitude of possible variations exists. It is also to be understood that exemplified embodiments are really only examples that are not to be construed in any way as limiting the scope, applicability, or configuration of the invention. Rather, the foregoing description and description enable the skilled artisan to practice the exemplary embodiments, and those of skill in the knowledge of the disclosed inventive concept may make various changes, for example, to the function or arrangement of particular elements recited in an exemplary embodiment. without departing from the scope defined by the claims and their legal equivalents, such as further explanation in the specification.

LIST OF REFERENCE NUMBERS

S1

Provide

S2

Determine

S3

Divide

S4

Combine

S5

Driving or simulating

S6

Determine

1

reference vehicle

2

test vehicle

3

interface

5

sensor unit

7

computer unit

11

first route

12

second route

21

first area

22

second area

100

device

Claims (10)

Method for carrying out a load test of a test vehicle (2), comprising the steps: Providing (S1) a time profile of first load variables, wherein the first load quantities are external influences and / or states of the reference vehicle (1) which are determined by measurement on a reference vehicle (1) when driving on a first route (11), the first route (11) being in a first area (21). is, Determining (S2) a first load spectrum from the temporal course of the first load variables, the first load collective indicating a frequency and / or a frequency and / or a height of respective first load variables, Subdividing (S3) a second area (22) into passable route sections and assigning a respective time profile of expected second load variables to each of the route sections, - combining (S4) the route sections of the second area (22) to a second route (12) such that a difference between a second load spectrum from the expected second load sizes and the first load spectrum is minimal among all possible combinations of route sections, and - driving or simulating (S5) a driving of the second route (12) by the test vehicle (2) and detecting actual second load quantities. Method according to Claim 1 wherein the first load quantities comprise at least one of the following magnitudes: a torque at an engine output shaft of the reference vehicle, a torque at a driven wheel of the reference vehicle, an engine speed of an engine of the reference vehicle, a speed of the reference vehicle, a time distribution of the engaged gears of a switchable one A transmission of the reference vehicle, and wherein the second load quantities at least one of the following variables: a torque at an engine output shaft of the test vehicle, a torque on a driven wheel of the test vehicle, an engine speed of an engine of the test vehicle, a speed of the test vehicle, a time distribution of engaged gears of a switchable transmission of the test vehicle. Method according to one of the preceding claims, wherein the test vehicle (2) and the reference vehicle (1) are identical. Method according to one of Claims 1 to 3 wherein the expected second load quantities are external influences and / or states of the reference vehicle (1) or of the test vehicle (2) determined by measurement on the reference vehicle (1) or the test vehicle (2) when driving on the second route (12). Method according to one of Claims 1 to 3 in which the expected second load variables are determined from a virtual model of a test track for the test vehicle (2), as well as from at least one of the following: dynamic model of the test vehicle (2), engine characteristic of an engine of the test vehicle (2), shift characteristic of an automatic transmission of the test vehicle Test vehicle (2), mass of the test vehicle (2), characteristics of wheels of the test vehicle (2), a dynamic driver model, an acceleration behavior of a driver from a dynamic driver model, a deceleration behavior of a driver from a dynamic driver model. Method according to one of the preceding claims, further comprising the step: - Determining (S6) of the difference between the second load collective and the first load collective after driving or simulating the driving of the second route (12) by the test vehicle (2). Method according to one of the preceding claims, wherein the combining of the route sections of the second area (22) to the second route (12) takes place such that the second route (12) is a closed curve. Method according to one of the preceding claims, wherein the combining of the route sections of the second area (22) to a second route (12) takes place in such a way that the time profile of the second load variables when driving on the second route (12) is as similar as possible to the time course of the first route Load sizes is. Apparatus (100) for preparing a load test of a test vehicle (2), comprising: - A first interface (3), which is designed to provide a time course of first load sizes, wherein the first load variables by measurement by means of a sensor unit (5) on the reference vehicle (1) when driving on a first route (11) acting external influences and / or states of the reference vehicle (1), wherein the first route (11) is located in a first area (21), and - A computing unit (7), which is designed to determine a first load spectrum from the time course of the first load sizes, the first load collective indicating a frequency and / or frequency and / or a height of respective load sizes, and for dividing a second area (22) is made into passable route sections and assigning a respective time history of expected second load quantities to each of the route sections, and that is configured to combine the route sections of the second area (22) to a second route (12), that is a difference between a second load spectrum of the second load sizes and the first load spectrum is minimal from all possible combinations of route sections. Test vehicle (2) with a device (100) according to Claim 9 ,

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