METHOD FOR DETERMINING ELASTIC PROPERTIES OF A MOTOR VEHICLE CABLE HARNESS

Abstract

A method for determining elastic properties of a motor vehicle cable harness is disclosed. At least one elastic property of at least one test cable is measured as a function of a force acting on the test cable. At least one elastic characteristic of the test cable is estimated from the measurement. At least one elastic property of a cable harness including a plurality of cables is calculated based on the at least one determined elastic characteristic.

Claims

1-14. (canceled)

15. A method for determining elastic property of a motor vehicle cable harness comprising: measuring an elastic property of a test cable as a function of a force acting on the test cable; determining an elastic characteristic of the test cable from the measurement; calculating an elastic property of a cable harness having a plurality of cables based on the determined elastic characteristic; and modeling the motor vehicle cable harness using the calculated elastic property.

16. The method according to claim 15, wherein further comprising measuring a plurality of test cables each with a different cable cross section.

17. The method according to claim 16, further comprising measuring a plurality of test cables each with a different sheathing.

18. The method according to claim 15, determining at least one elastic property of at least one cable differing from the test cable by approximation or interpolation based on the determined elastic characteristics.

19. The method according to claim 15, further comprising measuring a torsion of the test cable measured as a function of a torsional moment in order to determine a torsion characteristic as the elastic characteristic for indicating a linear relationship between the torsion and the torsional moment.

20. The method according to claim 15, further comprising measuring a bending of the test cable as a function of a bending moment acting on the test cable in order to determine at least one bending characteristic as the elastic characteristic ;for indicating a linear relationship between the bending and the bending moment.

21. The method according to claim 20, further comprising bending and measuring the test cable in such a manner to determine at least two bending characteristics as the elastic characteristic, which in each case indicates a linear relationship between the bending and the bending moment for different ranges of the bending moment.

22. The method according to claim 15, further comprising determining a function with a series of coefficients from the at least one measured elastic property of a series of test cables and the respective associated elastic characteristics and geometrical parameters by way of which at least one of the elastic characteristics of a cable can be determined.

23. The method according to claim 22, wherein at least one of the coefficients is dependent on a respective sheathing.

24. The method according to claim 22, wherein the function for a cable harness with a sheathing of type i has the following construction:
logP=c.sub.1i+c.sub.2ilogD+c.sub.3log.sup.2D+c.sub.4log.sup.2D+c.sub.5logA wherein: $D=\underset{i=1}{\overset{m}{.Math.}}.Math.n_i.Math.d_i$ n.sub.i indicates the number of the cables of type i; d.sub.i the respective measured elastic property of the test cable; $A=\frac{1}{N}.Math.\underset{i=1}{\overset{m}{.Math.}}.Math.n_i.Math.a_i$ a.sub.i is the nominal cross section of the cable of type i; and N is the total number of all cables belonging to the cable harness.

25. The method according to claim 24, wherein the function for a cable harness with a sheathing of type i has the following construction:
logP=c.sub.1i+c.sub.2ilogD+c.sub.3log.sup.2D+c.sub.4log.sup.2D+c.sub.5logN

26. The method according to claim 24, wherein at least the function is determined in each case for at least two different groups of sheathings.

27. A method for developing a motor vehicle, wherein at least one elastic property of a cable harness to be installed in the motor vehicle is determined prior to an installation in the motor vehicle according to the method of claim 15.

28. A non-transitory computer readable medium comprising computer program, which when executed on a computer, is configured to: measure an elastic property of a test cable as a function of a force acting on the test cable; determine an elastic characteristic of the test cable from the measurement; calculate an elastic property of a cable harness having a plurality of cables based on the determined elastic characteristic; and model the motor vehicle cable harness using the calculated elastic property.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The present disclosure will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements.

[0044] FIG. 1 shows a schematic lateral view of a motor vehicle;

[0045] FIG. 2 shows a cross section through a cable harness composed of a plurality of cables;

[0046] FIG. 3 shows a linear relationship between a torsion of a test cable and a torsional moment;

[0047] FIG. 4 shows a non-linear relationship however characterized by two linear regions between the bending of a test cable and the bending moment acting on the test cable;

[0048] FIG. 5 represents a computer-supported approximation of a linear bending behavior in certain sections on the basis of measurement data which were determined with a test cable; and

[0049] FIG. 6 illustrates a flow diagram of the method for determining the elastic characteristic of a motor vehicle cable harness.

DETAILED DESCRIPTION

[0050] The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any theory presented in the preceding background of the invention or the following detailed description.

[0051] In FIG. 1, a motor vehicle 1 with a motor vehicle body 2 and with a passenger cell is shown in a schematic lateral view, which delimits a motor vehicle interior 3 towards the outside. Furthermore, a cable harness 10 routed in the motor vehicle 1 marked with reference number 10 is schematically shown.

[0052] FIG. 2 shows such a cable harness 10 in cross section. The cable harness includes a plurality of individual cables 11, 12, 13 which are arranged lying against one another more or less regularly or irregularly and which are provided with a circumferential sheathing 30. As tape-like wrapping, the sheathing 30 can for example hold the cables 11, 12, 13 in the form and arrangement shown in FIG. 2. However, flexible tubes or hoses are alternatively also provided, which enclose the individual cables 11, 12, 13 of the cable harness 10 at least in longitudinal direction of the cables 11, 12, 13 in some sections.

[0053] The method for determining the elastic properties of a motor vehicle cable harness 10 serves in particular for simulating the elastic behavior during the laying of the cable harness 10 in the motor vehicle 1. In this regard, it is provided, according to the flow diagram according to FIG. 6, that in a first step 100 at least one elastic property, for example the torsion T or the bending B of one or a plurality of test cables 11, 12 is measured. Based on a measurement, during the course of which for example the torsion is measured as a function of a torsional moment or the bending as a function of a bending moment, corresponding elastic characteristics characterizing the torsion or the bending of the test cable 11, 12 concerned can be determined in the following step 102.

[0054] Based on those empirically determined characteristics, an applicable elastic property, for example a torsion or a bending of a cable harness 10 including one or a plurality of cables 11, 12, 13 can then be determined by calculation in a following step 104.

[0055] In this way, a comparatively large and heterogeneous group of variously configured cable harnesses 10 can be calculated and simulated with respect to its elastic behavior by measuring the elastic properties and determining the characteristics characterizing the elasticity of the test cables 11, 12 concerned. The calculation effort required for this is significantly smaller than when elastic properties of each individual cable and its interaction with other cables of a cable harness were to be determined by calculation separately and in each case individually.

[0056] In FIG. 3, the linear course of a torsion T as a function of a torsional moment TM acting on a pressed cable 11, 12 to be assumed here is shown. During the measurement of a test cable 11, 12 an approximately straight characteristic line is obtained, which insofar characterizes and determined a torsional characteristic G. For the bending B of a test cable 11, 12, a similar linear course of a bending characteristic can likewise be assumed. In this regard, a linear relationship between the bending B and the bending moment BM, thus an isotropic bending behavior of an individual test cable 11, 12 and of a cable harness 10 can be used as a base.

[0057] However, in FIG. 4 an anisotropic, pseudo-plastic behavior of a bending of a test cable 11, 12 is shown. The bending B runs approximately linearly with rising bending moment BM up to a point W of the bend. That linear region can be characterized with a bending characteristic E. For bending degrees greater than the limit value W, the characteristic however has a flatter course. There, a gradient that is smaller in magnitude or a lower bending characteristic K should consequently be assumed there. In FIG. 5, a plurality of characteristic lines 21, 22, 23, 24, 25 of a test cable 11 are shown, which show the relationship between a bending moment BM or force acting on the test cable 11 and the bending B resulting from this. Furthermore, the limit value W is stated, below which the bending behavior is linearly approximated on the basis of the bending characteristic E.

[0058] Above that limit value W for the bending B, the bending behavior with a further bending characteristic K is likewise described linearly and in the form of a straight line.

[0059] Such diagrams shown in FIG. 5 are carried out for a multitude of all kinds of test cables 11, 12 each with different cross sections, different sheathing types and different sheathing groups. Corresponding measurements are carried out both with respect to the torsion and also with respect to the bending so that both for the bending behavior and also for the torsional behavior the previously mentioned functions or equations F.sub.1 or F.sub.2 can be used as a base for characterizing and for describing the respective elastic behavior.

[0060] Based on the test cables 11, 12, the characteristics E, W and K as well as G in the case of a torsion can be determined. In a computer-supported manner, the coefficients c1.sub.ic2.sub.i, c3, c4 and c5 can then be numerically determined for the all kinds of test cables and for all kinds of sheathing types in each case of a sheathing group. Once a function F.sub.1 or F.sub.2 has been determined based on the test cables 11, 12, the respective elastic characteristic, in particular E, G or K can be determined by calculation, in each case sheathing type-specifically for a cable set with a known number of different dimensioned cables, in particular with a number of cables with different cross sections.

[0061] For different sheathing groups, for example for sheathings based on tubes or sheathings based on wrappings, different functions F.sub.1 or F.sub.2 can each be determined separately based on corresponding test cables.

[0062] Measuring the at least one elastic property of the test cables 11, 12, determining at least one elastic characteristic of the test cable concerned, determining the coefficients c1, c2, c3, c4, c5 and of the functions F.sub.1 or F.sub.2 and also the determining of elastic characteristics of cables 13, cable bundles 20 or cable harnesses 10 which are not measured takes place in a computer-supported manner In this regard, the previously described computer program is designed to carry out all method steps described here and to determine in a computer-supported manner the elastic properties of cable harnesses based on the previously determined functions F.sub.1 or F.sub.2. Here, a method of the least squares can be used.

[0063] While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the invention as set forth in the appended claims and their legal equivalents.