Method for determining the position of a point of attachment of an electric wiring harness in a vehicle

Abstract

The invention relates to a method for determining a position of a point of attachment (P301) and a direction of arrival (D301) of an electric wiring harness (301) on a support element (10) of a motor vehicle. According to the invention, this method comprises the steps of: - determining positioning constraints of the harness in the vehicle; - acquiring the geometry of the support element; - creating a search zone (Z1) on the support element in which candidate points of attachment (P20) are distributed; - calculating, for each candidate point of attachment and for at least one direction of arrival of the harness on the candidate point of attachment, a path (T301) of the harness; and - selecting the path depending on whether or not it satisfies at least part of the determined positioning constraints.

Description

DESCRIPTION TITLE OF THE INVENTION: METHOD FOR DETERMINING THE POSITION OF AN ATTACHMENT POINT OF AN ELECTRICAL CABLE HARNESS IN A VEHICLE TECHNICAL FIELD OF THE INVENTION

[0001] The present invention relates generally to the arrangement of components of a motor vehicle.

[0002] It relates more particularly to a method for determining the position and direction of attachment of a bundle of electrical cables to a support on board a motor vehicle.

[0003] The invention finds a particularly advantageous application when the support is an internal combustion engine of a motor vehicle, although it also applies when the vehicle is of the electric type. STATE OF THE ART

[0004] Motor vehicles have many electrical and electronic components, which need to be connected together by electrical cables.

[0005] Typically, a vehicle's powertrain has many sensors and actuators that connect to the vehicle's electrical network through cables assembled into a large diameter bundle.

[0006] However, while the vehicle computers that control these sensors and actuators are generally rigidly attached to the vehicle chassis, the same is not true for the powertrain and its equipment. In fact, to absorb the vibrations and stresses that are exerted, such a powertrain is generally attached to the chassis in a "flexible" manner, for example via rubber mounts more commonly known as "silent blocks". These mounts are in fact designed to absorb the vibrations generated by the powertrain, the movements of the powertrain, for example in the event of strong acceleration or when driving over a pothole, etc.

[0007] Therefore, the harness must be attached, on one side, to the chassis at a stable attachment point, and, on the other, to the powertrain at an attachment point which is movable relative to the chassis.

[0008] Additionally, the housing in which the powertrain is located is a very crowded area with hot and moving parts. The harness must therefore be attached to the powertrain in such a way that it passes away from these various parts, regardless of the position of the powertrain relative to the chassis.

[0009] We therefore understand that finding an attachment point for the cable harness electrical wiring on the powertrain and a direction of arrival of this harness on this attachment point turns out to be a complicated and tedious operation. PRESENTATION OF THE INVENTION

[0010] In order to facilitate this operation, the present invention proposes to consider all the constraints to be taken into account so that the harness is properly installed in the engine housing of the vehicle, and to carry out a large number of tests of the attachment point and direction of arrival of the harness at this point in order to validate them or not according to the defined constraints.

[0011] More particularly, the invention proposes a method for determining a position of an attachment point of an electrical cable bundle on a support of a motor vehicle and a direction of arrival of the electrical cable bundle at this attachment point, which comprises steps of: - determination of constraints on the positioning of the beam in the vehicle, which relate at least to the beam and the support, - acquisition of the geometry of the support, - creation of a search area on the support or near the support, in which candidate attachment points are distributed, - calculation, for each candidate attachment point and for at least one direction of arrival of the beam on the candidate attachment point, of a trajectory of the beam, - selection of said trajectory according to whether or not it satisfies at least part of the determined positioning constraints.

[0012] Thus, thanks to the invention, it is possible to sort among the very many trajectories that the beam could take those which respect the constraints which have been defined. The invention thus makes it possible, when applied to a sufficient number of candidate attachment points, to find a point or an area in which the beam can be fixed.

[0013] Other advantageous and non-limiting characteristics of the method according to the invention, taken individually or in all technically possible combinations, are the following: - in the calculation step, the trajectory is calculated by considering that the beam is fixed on a fixed part of the motor vehicle at a fixing point, with a starting direction from this fixing point which is predetermined; - the motor vehicle comprising a chassis and a powertrain mounted movably on the chassis, the fixed part comprising said chassis and the support comprising said powertrain, in the selection step, said trajectory is selected according to whether or not it satisfies at least part of the positioning constraints determined for several distinct positions of the powertrain relative to the chassis; - said search area comprises an intersection between an external surface of the support and a ball centered on the fixing point; - said search zone comprises second balls distributed on and / or in a first ball of larger diameter, which is centered on a point belonging to the external surface of the support or located close to this external surface; - at the selection step, said trajectory is selected if it has a minimum radius of curvature which is greater than a predetermined threshold; - at the selection step, said trajectory is selected if it has a length which is less than a predetermined threshold; - at the calculation stage, it is determined whether the beam can be implanted on the support as a function, on the one hand, of a distance between the support and the candidate attachment point, and, on the other hand, of the direction of arrival relative to the support then, if the beam cannot be implanted, the position of the candidate attachment point is corrected by moving it away from the support; - said constraints include at least: n a maximum length for the beam, n a minimum radius of curvature for the beam, n possibly, an area of ​​the support where no attachment of the beam is possible, and n an area of ​​the environment of the support where components of the motor vehicle are located; - after the selection step, a step is provided for storing each selected trajectory in a file showing at least, for each trajectory, the length of the trajectory and the minimum radius of curvature of the trajectory; - after the acquisition step, the geometry of the support is simplified by approximating the shape of its external surface.

[0014] The invention also relates more generally to a method of manufacturing a motor vehicle comprising: - a design operation during which the determination method in accordance with the invention is implemented, then - a vehicle assembly operation during which the harness is fixed to the support at the attachment point and in the direction of arrival.

[0015] Of course, the various features, variants and embodiments of the invention may be combined with each other in various combinations to the extent that they are not incompatible or mutually exclusive. DETAILED DESCRIPTION OF THE INVENTION

[0016] The description which follows with regard to the attached drawings, given for the purpose of non-limiting examples, will make it clear what the invention consists of and how it can be implemented.

[0017] On the attached drawings:

[0018] - Figure 1 represents in the form of diagrams different operations applied to a file illustrating the geometry of an internal combustion engine in order to find an attachment point according to a method in accordance with the present invention;

[0019] - Figure 2 is a block diagram illustrating the different steps of implementing the method according to the present invention.

[0020] A motor vehicle typically has a chassis that supports numerous pieces of equipment, including a powertrain.

[0021] In the following, the powertrain will be considered to comprise an internal combustion engine, but the invention would also apply to an electric vehicle. In the following, the chassis may be considered to comprise not only structural beam elements, but also bodywork elements.

[0022] The vehicle also contains electronic and electrical components that must be connected together using cables.

[0023] To facilitate the wiring of these components, where possible, the individual cables are grouped into a bundle. Such a bundle, when the cables are wound together in a spiral, forms a relatively inflexible strand.

[0024] Such a beam then has significant rigidity and weight, so it must be carefully secured in the vehicle.

[0025] This fixing proves difficult in practice when the fixing area is very cluttered and it must be done, on one side, on a fixed part of the vehicle and, on the other, on a mobile part of the vehicle (these parts being described as fixed and mobile in relation to the chassis of the vehicle).

[0026] Thus, by way of non-limiting example, when the harness is fixed, on the one hand, to the chassis (considered immobile) at a well-defined fixing point and it must be fixed, on the other hand, to the internal combustion engine of this vehicle (hereinafter referred to as "engine"), finding a suitable attachment point on the engine proves to be a delicate operation.

[0027] In fact, the engine is fixed to the chassis by rubber pads, so that it can move on it in translation (with a movement generally of the order of plus or minus 1 cm) and in pivoting (with a movement generally of the order of plus or minus a few degrees) around a neutral position (defined when stationary, engine off).

[0028] In addition, the engine includes hot parts as well as moving parts relative to its casing (exhaust manifold, belts, actuators, etc.), where it is not possible to attach the harness. These parts will hereinafter be referred to as "impossibility zones".

[0029] In this presentation, it will be considered that the attachment point P30 of the beam on the chassis has already been chosen and that it is no longer possible to modify it, and that this beam extends from this attachment point P30 in a starting direction D30 already assigned. The first section 30 of the beam is then shown in the third diagram of figure 1.

[0030] In practice, the shape and position of this first section 30 are predefined for the following reason. A motor vehicle model is designed so as to be able to accommodate different engines, i.e. engines of different shapes. The attachment point of the harness on the chassis is then always the same, regardless of the vehicle's engine. On the other hand, the attachment point of the harness on the engine will necessarily vary depending on the engine, which is why this attachment point is chosen later.

[0031] It will be considered here, as shown in the last diagram of figure 1, that the harness 301 extends in length from the fixing point P30 to the attachment point P301, along a trajectory T301, and therefore that it ends at its attachment point on the engine. Indeed, beyond this, the cables of the harness 301 separate to go towards the electrical and electronic components of the engine.

[0032] In this context, the object of the present invention consists in finding the position of at least one attachment point P301 where to fix the beam 301 on the engine 10 and a direction of arrival D301 of the beam 301 on this point, so that the beam 301 is never constrained even when the engine moves relative to the chassis.

[0033] The search for the possible P301 attachment point(s) is carried out here using a computer processing unit, hereinafter called a calculator.

[0034] This calculator typically includes a processor, memory and various input and output interfaces.

[0035] Thanks to its input interfaces, the calculator is adapted to receive different files, typically a modeling file of the engine 10 and its environment.

[0036] Thanks to its output interfaces, the calculator is suitable for transmitting data to a display screen available to a vehicle designer.

[0037] Thanks to its memory, the calculator stores a computer application, consisting of computer programs including instructions whose execution by the processor allows the calculator to implement the method described below.

[0038] In very general terms, to find an attachment point P301 of the harness 301 on the engine 10 and an arrival direction D301, it is planned to: - fill in a file listing different constraints to take into account when positioning the beam (minimum radius of curvature of the beam, areas of impossibility, areas of the environment occupied by other elements of the vehicle, etc.), - determine the geometry of the engine (preferably by simplifying it), - set a search area on the engine or near the engine, in which candidate attachment points P20, P200 can then be defined, - calculate, for each candidate attachment point P20, P200, trajectories that the beam could take in order to reach these candidate attachment points with predefined arrival directions, - select each beam path that conforms to at least part of the constraints defined in the file.

[0039] Here, we can clarify the notion of "trajectory". A trajectory will correspond to the curve followed by the bundle (and more precisely by the central fiber of the bundle) from the fixation point P30 to the attachment point considered.

[0040] Figure 2 shows in detail the different steps of the method for determining the position of the attachment point P301 and the direction of arrival D301 of the beam 301 at this point. This method can now be described in more detail.

[0041] It is assumed at this stage that the geometry of the vehicle, and in particular that of the chassis, the engine and its immediate environment, is known and recorded in the computer's memory.

[0042] The calculator therefore has a detailed modeling file of the engine 10, which modeling is illustrated in the first diagram at the top left of figure 1.

[0043] This file also models elements located in the engine environment, including a radiator 51, an engine cover 52 and a portion of the chassis 53, as illustrated in the diagram at the bottom left of Figure 1.

[0044] The first step E0 consists of the designer generating the file listing the constraints to be taken into account to position the beam 301 in the vehicle, and saving it in the computer memory.

[0045] This file lists at least one constraint on the beam (typically the minimum bending radius to avoid damaging it), at least one constraint on the engine (for example the possible position of the impossibility zones) and at least one constraint on the engine environment (for example the areas where vehicle components are already located).

[0046] Here, and preferably, this file lists more precisely the following nine constraints.

[0047] The first constraint is a range of acceptable lengths for the beam 301, between the attachment point P30 on the chassis and the attachment point P301 on the engine 10. According to this first constraint, the length of the beam, measured curvilinearly, must be between a lower limit (for example 200 mm) and an upper limit (for example 300 mm).

[0048] The lower limit of this range is chosen so that the beam is long enough to avoid fatigue problems when the motor 10 moves. The upper limit is chosen so that the beam 301 does not oscillate too much, is not too heavy and is not too expensive.

[0049] The second constraint, which depends on the diameter of the beam 301, is the minimum radius of curvature that the beam can present along its trajectory (between the fixing point P30 and the attachment point P301).

[0050] This minimum radius of curvature is for example chosen to be equal to three times the diameter of the beam 301. It will be noted that this constraint must necessarily be respected when the engine is in neutral position, that it must preferably be respected whatever the position of the engine 10 on the chassis other than this neutral position.

[0051] The third constraint is the minimum bending radius that the cables in the harness can have individually (downstream of the P301 attachment point, when they separate).

[0052] The fourth constraint is the position of the attachment point P30 of the beam on the chassis and the starting direction D30 taken by the beam 301 at this point. As explained above, these positions and directions are in fact already defined.

[0053] The fifth constraint is the size of the initial search area for the attachment point P301. This size is in practice defined by a maximum search distance from the attachment point P30 (or from another predefined point, as will be explained later).

[0054] This fifth constraint also includes a density or number of points to be tested in this initial search area.

[0055] The sixth constraint is formed from the list of components of the motor vehicle likely to hinder the passage of the beam 301. This list includes an identifier for each component, and at least one characteristic indicating whether it is a component of the environment or a component of the engine, and in this case whether it is an impossibility zone or not (hot or moving part). As specified above, the position and geometry of these components are also already recorded in the modeling file of the engine and its environment.

[0056] It should be noted that any areas of impossibility (i.e. areas where attachment of the beam 301 is impossible) may be defined by a central point and a configurable exclusion distance around this point.

[0057] The seventh constraint involves a cone apex angle. This cone will have an apex centered on the attachment point to be tested and will be open in a direction normal to the surface of the engine at this attachment point. This cone will delimit the area in which the beam's arrival directions at the attachment point will have to be tested. If we do not wish to restrict the search for the arrival direction D301 by this constraint, this angle can be considered equal to 360°.

[0058] Here, this seventh constraint also includes a density or number of arrival directions to be tested in this cone.

[0059] The eighth constraint corresponds to the possible deflections of the engine relative to the chassis. This eighth constraint could, for example, include the maximum deflections, in terms of distances and angles, that the engine 10 can take relative to the chassis.

[0060] However, it is presented here in the form of a list of deflections in different "use cases" of the vehicle. These use cases are for example: strong acceleration when the first gear is engaged, strong acceleration when reverse gear is engaged, a strong jolt when passing over a pothole... Thus, when searching for the attachment point P301, it will be possible to check whether the beam is constrained or not in each of these use cases.

[0061] The ninth constraint is a clearance to be respected. This clearance thus imposes a minimum distance to be respected between the beam 301 on one side, and the engine and its environment on the other.

[0062] The number of constraints taken into account could of course differ. Thus, alternatively, one could take into account a smaller number of constraints, or a larger number.

[0063] It should also be noted here that at least some of these constraints can be described as "soft constraints" in the sense that they must preferably be respected, but that a deviation may be tolerated. This will become clear from reading the rest of this presentation.

[0064] The second step E1 consists of the calculator simplifying the modeling of the engine 10.

[0065] This step is not essential but it will simplify the calculations, and therefore significantly reduce the time needed to carry out these calculations.

[0066] The idea is to restrict the size of the engine modeling file, reducing it by at least 10 times. Typically, if this modeling file was between 500 and 1000 MB, the goal will be to reduce it to less than 10 MB.

[0067] To do this, the simplification proposes to keep in memory only the geometry of the external surface of the engine 10, and preferably also to simplify the shape of this external surface in order to represent it in the form of a sheet 20 (illustrated at the top right of figure 1).

[0068] This simplification step could be implemented in different ways. Here, it includes the following three sub-steps.

[0069] The first sub-step consists of dividing the engine into a predefined number of sections. To do this, the shapes and positions of the intersection lines between the external surface of the engine model 10 and several parallel section planes are determined. These section planes are spaced two by two by a constant and predefined distance. They preferably extend orthogonally to the greatest length of the engine 10.

[0070] The second sub-step consists, by a process of interpolation, in finding the shape of a continuous surface passing through the intersection lines.

[0071] The third sub-step consists of removing from this continuous surface the zones of impossibility (taking into account the 6th constraint mentioned above), which generates holes 21 in the sheet 20.

[0072] Once the shape of this sheet 20 is known, the third step E2 consists of defining candidate attachment points P20, P200 where to test whether the attachment of the beam 301 to the engine 10 is possible. It can already be noted that the next step will then consist of selecting, among these candidates, those which are usable (taking into account the defined constraints).

[0073] These candidate attachment points P20, P200 may be located on the sheet 20, or close to it. Indeed, the attachment point P301 which will be selected may be placed on the engine 10, or at a distance from it, in which case a spacer and fixing tab must be used to make this attachment.

[0074] It should be noted in this regard that the P301 attachment point will always be located as close as possible to the external surface of the motor, taking into account constraints (the spacing must allow the wiring to continue so that the cable does not interfere with the motor, it must also allow clearances with the various parts).

[0075] Different methods can be used to define these candidate attachment points P20, P200.

[0076] We can give two here.

[0077] These two methods can be used as an alternative or in addition to each other.

[0078] The first method M1 consists, as shown in figure 1, in creating a solid ball 100 centered on the attachment point P30 of the beam 301 on the chassis (taking into account the 4th constraint mentioned above), with a radius equal to the maximum distance in which the attachment point must be sought (taking into account the 5th constraint mentioned above).

[0079] The intersection between this ball 100 and the sheet 20 forms a surface defining a search zone Z1 in which candidate attachment points P20 must be distributed.

[0080] A point cloud is then created on this search area Z1, with the density predefined. This mesh therefore makes it possible to define the candidate P20 attachment points.

[0081] Note that the density may initially be relatively low, in order to simplify the calculations. In this event, steps E2 and following may then be repeated at least once by restricting the size of the search area and increasing the density in this area.

[0082] The second method M2 can be used as a variant of the first method M1 or as a complement to define more candidate P200 attachment points.

[0083] For example, we could use this second method if the intersection between ball 100 and tablecloth 20 formed an empty set.

[0084] We will consider here that this second method is used during a repetition of steps E2 and following, while one or more attachment points have already been validated during the first implementation of steps E2 and following.

[0085] In our example, we can consider that we have selected, during this first implementation, two candidate attachment points.

[0086] Then, during the second implementation of step E2, a first ball 200 is defined for each of these two candidate attachment points (see figure 1). The center of each first ball 200 is merged with the corresponding candidate attachment point. The radius of this ball is predefined (its value is editable by the user).

[0087] Note that alternatively, one could use a geometric figure other than a loop, typically a cube or even a non-regular geometric figure.

[0088] Then two processes can be used.

[0089] The first and simplest process consists of distributing new candidate attachment points P200 on and in this first ball 200.

[0090] The second process, allowing better testing of the search area, consists of defining new small balls 201 centered on the surface of each first ball 200 and with a radius of, for example, between 2 mm and 10 cm, then distributing new candidate attachment points P200 on these new small balls 201.

[0091] Regardless of the method M1 and / or M2 used, at this stage the computer has candidate attachment points P20, P200 where to test whether or not it will be possible to attach harness 301 to engine 10.

[0092] The third E3, shown in detail in Figure 2, then consists of carrying out these tests by tracing trajectories that the beam could take (we speak of “dynamic loops”) and checking that these trajectories are valid given the predefined constraints. Then, only the valid trajectories will be retained to decide where to attach the beam 301 to the motor 10.

[0093] The third step is then implemented in a plurality of sub-steps.

[0094] The first sub-step S0 consists of choosing any one of the attachment points P20, P200 candidates to be tested (hereinafter referred to as “candidate attachment point considered”).

[0095] During the second sub-step S2, the computer associates with this candidate attachment point considered a first direction of arrival D301 of the beam 301 on this point. This first direction of arrival to be tested is chosen randomly, from among the directions to be tested in the cone defined in the constraint file.

[0096] Then, the calculator checks whether the continuation of the trajectory of the cables of the harness will be possible or not, beyond this candidate attachment point P20, P200 considered.

[0097] Indeed, the harness will not be cut after its attachment point on the engine 10. On the contrary, as explained above, it will divide into a plurality of individual cables.

[0098] To carry out this check, the computer determines whether, taking into account the minimum bending radius of the individual cables of harness 301 (3° constraint), it is possible to trace a path for these individual cables which does not intersect the engine.

[0099] If tracing such a trajectory is possible, the method continues in a sub-step S6. Otherwise, the computer implements, before sub-step S6, a sub-step S4 which consists of moving the candidate attachment point P20, P200 considered.

[0100] This movement is carried out in the opposite direction to the tested arrival direction D301, thus moving the candidate attachment point considered away from the motor 10. This moving away is carried out over a sufficient length to prevent the trajectories of the individual cables of the harness from intersecting the motor 10.

[0101] Once the candidate attachment point considered has been well defined and the direction of arrival chosen, during sub-step S6, the computer determines the trajectory that the beam can take between the attachment point P30 and the candidate attachment point P20, P200 considered.

[0102] It is understood that a plurality of trajectories would be possible. But here, the trajectory chosen is the one for which the length of the beam 301 is the shortest (this length being of course chosen so as to be sufficient in all the defined use cases).

[0103] Note that the ninth constraint is then used to verify that the chosen trajectory respects it.

[0104] After this sub-step S6, this length and the minimum radius of curvature of the trajectory are compared with the values ​​recorded in the constraint file, for different use cases.

[0105] More precisely, during a sub-step S8, the computer considers the engine in its most critical position and it checks that the length of the beam 301 between the attachment point P30 and the candidate attachment point considered is included in the range of lengths defined in the file (1st constraint).

[0106] If this is not the case, this configuration is not retained (sub-step S26). In other words, the pair “candidate attachment point considered” and “direction of arrival” is rejected since the trajectory is judged to be too long or too short.

[0107] On the other hand, if this length is included in the defined range of values, the calculator implements a sub-step S10 during which it checks that the minimum radius of curvature of the trajectory is greater than the predefined radius of curvature threshold (2° constraint).

[0108] If this is not the case, this configuration is not retained (sub-step S26).

[0109] Otherwise, the method continues in a substep S12.

[0110] During this sub-step S12, the computer calculates the minimum radius of curvature of the trajectory when the engine is in each of the other positions (distinct from the neutral position) defined by the different use cases listed in the 8th constraint.

[0111] If, for a predefined part of the use cases, this minimum radius of curvature is greater than the defined radius of curvature threshold, the calculator retains this configuration (sub-step S16), which means that the triplet “candidate fixing point considered”, “direction of arrival” and “trajectory” is selected.

[0112] Typically, a configuration can be considered selected if the minimum beam curvature radius is greater than the curvature radius threshold defined for more than half of the use cases.

[0113] Otherwise, the calculator can either directly reject this configuration (sub-step S26), or attempt to modify it (sub-step S14).

[0114] To try to modify it, the computer uses the same candidate attachment point and the same arrival direction, but it looks for a new trajectory corresponding to a longer beam length, checking that this length remains within the predefined range of values. Then it repeats sub-step S12 with this new trajectory.

[0115] Sub-steps S12 and S14 can be repeated several times by progressively increasing the length of the trajectory until reaching the defined length threshold.

[0116] Then, if no solution is found, the configuration is rejected (sub-step S26). Otherwise, the configuration is retained during sub-step S16.

[0117] If a configuration has been selected, the process continues in a sub-step S18 during which the computer checks whether, for the candidate attachment point considered, all the arrival directions have been tested. Indeed, as defined in the constraint file, it is planned to test different arrival trajectories contained in a cone (taking into account the 7th constraint).

[0118] For example, one may wish to test a predefined number of arrival directions contained within a cone open to 180 degrees, and regularly distributed within this cone.

[0119] Then, as long as all arrival directions have not been tested with the candidate attachment point considered, the process will repeat from sub-step S2.

[0120] Then, when all the arrival directions have been tested, the computer will determine whether there are any other candidate attachment points that have not yet been tested. Then, until all the candidate attachment points have been tested, the process will repeat itself from sub-step S0, each time considering a new candidate attachment point and, for each of these points, all the possible arrival directions.

[0121] When all the configurations have been tested, the process continues in a sub-step S22 during which all the retained configurations are stored in a file.

[0122] At this point, the designer can review the file. If this file contains only one configuration, the choice of the most suitable configuration is obvious.

[0123] But in practice, a large number of configurations are stored in the file and choosing the most suitable configuration turns out to be more complicated.

[0124] Therefore, it is advantageous to provide that during a sub-step S24, the calculator establishes a dynamic table listing the selected configurations in a way that is easier for the designer to understand, thus facilitating his choice of ideal configuration.

[0125] This dynamic table, for example, has eight parallel columns, each column having a y-axis.

[0126] The first column represents on its axis a range of trajectory length values, for example from 200 to 300mm (the 1st constraint being satisfied, this column allows us to favor configurations in which the length of the beam is reduced).

[0127] The second column represents on its axis a range of percentages of use cases for which the trajectory curvature radius was greater than the desired threshold, this range of percentages going for example from 50% to 100%.

[0128] The third column represents on its axis a range of radii of curvature, allowing to indicate the minimum radius of curvature of a trajectory (the 2nd constraint being satisfied, this column allows to favor configurations in which the minimum radius of curvature of the trajectory is high).

[0129] The fourth column represents on its axis a range of deviations of radii of curvature, allowing to indicate the maximum deviation between the minimum radii of curvature of the trajectories calculated for the different use cases. Thus, the smaller this deviation, the more the displacement of the beam will be restricted when the motor moves, which is preferable.

[0130] The fifth column indicates on its axis a range of distances allowing to indicate the minimum distance between the trajectory and the motor 10. It allows to check that the clearance between the beam and the motor is sufficient.

[0131] The sixth column indicates on its axis a range of distances allowing to indicate the minimum distance between the trajectory and the elements of the engine's environment.

[0132] The seventh column indicates on its axis a range of distances allowing the smallest of the two minimum distances mentioned above to be indicated (which allows us to check whether the 9th constraint is satisfied).

[0133] The eighth column gives on its axis a range of notes allowing to indicate the note assigned to each of the trajectories according to the aforementioned data. The note is calculated automatically by the calculator.

[0134] So, each configuration is represented on this dynamic table by a line that passes from one column to another.

[0135] By clicking on a feature, it will then be possible to highlight it and display a window indicating the characteristics of the configuration.

[0136] By selecting a range of values ​​in a column, it will be possible to highlight the different lines corresponding to the different configurations that respect this range.

[0137] By selecting several value ranges across several columns, it will be possible to highlight the different lines corresponding to the different configurations that simultaneously respect these ranges, which makes it easier to find the configuration that is considered most suitable.

[0138] Once the attachment point, arrival direction and trajectory have been chosen, these data are integrated into the vehicle modeling. From then on, during the vehicle assembly process, the harness can be attached to the engine at an attachment point with known coordinates, using a connector ensuring the harness arrives at this attachment point according to the selected arrival direction D301.

[0139] The present invention is in no way limited to the embodiment described and shown, but those skilled in the art will be able to provide any variation in accordance with the invention.

Claims

CLAIMS 1. Method for determining a position of an attachment point (P301) and a direction of arrival (D301) of a bundle (301) of electrical cables on a support (10) of a motor vehicle, characterized in that it comprises steps of: - determination of positioning constraints of the beam (301) in the vehicle, which relate at least to the beam (301) and to the support (10), - acquisition of the geometry of the support (10), - creation of a search zone (Z1) on the support (10) or near the support (10), in which candidate attachment points (P20, P200) are distributed, - calculation, for each candidate attachment point (P20, P200) and for at least one direction of arrival of the beam (301) on the candidate attachment point (P20, P200), of a trajectory (T301) of the beam (301), - selection of said trajectory (T301) depending on whether or not it satisfies at least part of the determined positioning constraints.

2. Determination method according to claim 1, in which, in the calculation step, the trajectory (T301) is calculated by considering that the beam (301) is fixed on a fixed part of the motor vehicle at a fixing point (P30), with a starting direction from this fixing point (P30) which is predetermined.

3. Determination method according to claim 2, in which the motor vehicle comprising a chassis and a powertrain (10) mounted movably on the chassis, the fixed part comprising said chassis and the support comprising said powertrain (10), in the selection step, said trajectory (T301) is selected according to whether or not it satisfies at least part of the positioning constraints determined for several distinct positions of the powertrain (10) relative to the chassis.

4. Determination method according to one of claims 2 and 3, in which said search zone (Z1) comprises an intersection between an external surface of the support (10) and a ball (100) centered on the fixing point (P30).

5. Determination method according to one of claims 1 to 4, in which said search zone comprises second balls (201) distributed on and / or in a first ball (200) of larger diameter, which is centered on a point belonging to the external surface of the support (10) or located close to this external surface.

6. Determination method according to one of claims 1 to 5, in which, in the selection step, said trajectory (T301) is selected if it has a radius of minimum curvature which is greater than a predetermined threshold. determination method according to one of claims 1 to 6, wherein, in the selection step, said trajectory (T301) is selected if it has a length which is less than a predetermined threshold. determination method according to one of claims 1 to 7, wherein, in the calculation step, it is determined whether the beam is implantable on the support (10) as a function of a distance between the support (10) and the candidate attachment point (P20, P200) and of the direction of arrival (D301) relative to the support (10) then, if the beam is not implantable, the position of the candidate attachment point (P20, P200) is corrected by moving it away from the support (10). determination method according to one of claims 1 to 8, wherein said constraints comprise at least: - a maximum length for the beam (301), - a minimum radius of curvature for the beam (301), and - an area of ​​the environment of the support (10) where components of the motor vehicle are located. determination method according to one of claims 1 to 9, in which, after the selection step, a step of storing each trajectory (T301) selected in a file is provided showing at least, for each trajectory (T301), the length of the trajectory (T301) and the minimum radius of curvature of the trajectory (T301). determination method according to one of claims 1 to 10, in which, after the acquisition step, the geometry of the support (10) is simplified by approximating the shape of its external surface.

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