Method for determining an optimal time for a change of position of tires of a vehicle

Abstract

Method for determining an optimal time for a change of position of tires (4) of a vehicle (1), comprising - determining a relationship between a mileage and a tread depth for a tire (4) in a first position and a tire (4) in a second position; - Determining an expected remaining service life for both tires (4) depending on a time for a change of position and - Minimizing the difference between the expected remaining service life for both tires (4) depending on the time for a change of position of the tires (4).

Description

[0001] Vehicle tires experience wear during use, which can include uneven wear across the tread. Causes can include heavy loads, driving behavior, and road surface conditions. Tramline wear, for example, can occur depending on the tire's position on the vehicle, with the inner and outer shoulders of the tire wearing more than usual.

[0002] In commercial vehicles with dual tires, the tires on the same axle sometimes exhibit different levels of wear. Therefore, they also have different service lives and must be replaced at different times. Typically, however, all tires on an axle are replaced when one of them reaches its minimum tread depth. This results in tires being removed from the vehicle too early.

[0003] To counteract this, tires are sometimes swapped in different positions before one of the tires has reached its minimum tread depth. However, this involves considerable inspection effort.

[0004] It is an object of the present invention to provide a method for determining an optimal time for a change in the position of tires of a vehicle, which method can be carried out as largely automatically as possible and with which vehicle tires can be driven as far as possible to their minimum tread depth.

[0005] This problem is solved by the subject matter of the independent claim. Advantageous embodiments and further developments are the subject matter of the dependent claims.

[0006] According to one aspect of the invention, a method for determining an optimal time for changing the position of tires of a vehicle is provided. The method comprises determining a relationship between a mileage and a tread depth for a tire in a first position and a tire in a second position. It further comprises determining an expected remaining service life for both tires as a function of a time for a position change. The method further comprises minimizing the difference between the expected remaining service life for both tires as a function of the time for a position change of the tires.

[0007] A tire's position refers to the position at which it is mounted on a vehicle axle. It also refers to its direction of rotation. The time for a position change corresponds to the tread depth at which the position change occurs. Therefore, the term "time of a position change" can be understood as synonymous with the term "tread depth at the time of the position change."

[0008] According to the method, on the one hand, a remaining service life of the tires is predicted and, on the other hand, the difference between the expected remaining service life for both tires is minimized as a function of the time of the position change as an objective function using an optimization algorithm.

[0009] The advantage of this process is that the optimized repositioning of the vehicle's tires ensures optimal utilization of the tread depth for both tires. Both tires reach the minimum tread depth at the same time, if possible. Replacing both tires when one of them has reached the minimum tread depth does not result in the premature removal of a still usable tire. This is particularly sustainable and also saves costs and time, as service intervals can be optimized accordingly.

[0010] The method can be carried out for a plurality of tire pairs of a vehicle or for more than two tires at the same time.

[0011] In this way, it is possible to consider different partners for a change of position and to select the most suitable pairs of tires.

[0012] The method can be executed during vehicle operation by a computing unit located in the vehicle. In particular, the step of minimizing the difference between the expected remaining service life of both tires depending on the time for a tire change can be performed as an on-board service. The relationship between mileage and tread depth for a tire can be based on a model.

[0013] Alternatively, it is also possible to execute the process partially or completely on an external computing unit and in particular in the cloud.

[0014] According to one embodiment of the invention, for example, the relationship between mileage and tread depth for a tire in a first position and a tire in a second position is determined using test drives. Alternatively or additionally, simulations can be used for this purpose.

[0015] The data obtained through test drives and / or simulations can be extended to previously unconsidered routes through machine learning. Determining the optimal timing for tire repositioning is independent of the method chosen to determine the relationship between mileage and tire tread depth.

[0016] In particular, the position at which a tire is mounted can also be taken into account. In particular, the relationship between a tire's position and wear, especially uneven wear, can be learned.

[0017] The method has the advantage that it is easy to implement and does not require the transfer of large amounts of data.

[0018] The method reliably provides a relationship between the mileage and the tread depth for a tire, which can then be used to determine the optimal time for a change of position.

[0019] According to one aspect of the invention, a computer program product is provided, comprising instructions that, when executed by a computer, cause the computer to perform the described method. This may, in particular, at least in part, also be a web or cloud application.

[0020] According to a further aspect of the invention, a computer-readable medium is provided, comprising instructions which, when executed by a computer, cause the computer to carry out the described method.

[0021] Embodiments of the invention are described below by way of example with reference to schematic drawings. Fig. 1 shows a method according to an embodiment of the invention for determining an optimal time for a change in position of vehicle tires; Fig. Figure 2 shows schematically a vehicle with several tires, whose positions are determined according to the Fig. 1 described procedures; Fig. Figure 3 shows the expected remaining service life for two vehicle tires that were replaced relatively early; Fig. Figure 4 shows the expected remaining service life for two vehicle tires that were replaced relatively late and Fig. Figure 5 shows the expected remaining service life for two vehicle tires that were replaced at an optimal time.

[0022] Fig. 1 shows steps of a method for determining an optimal time for a change of position of tires of a vehicle according to an embodiment of the invention.

[0023] First, a relationship between a mileage and a tread depth is determined for a tire in a first position and a tire in a second position. This step 100 can be performed, for example, using a self-learning model, and the relationship between the mileage and the tread depth can be saved and made available at a later time. Step 100 can be performed in advance on a computing unit outside the vehicle and, in particular, also for a fleet with a large number of vehicles.

[0024] In step 20, the expected remaining service life is determined for both tires. The expected remaining service life depends on the tire position and therefore also on the time for the tire change. If the tires are swapped very late, the tire in the more heavily used position will already be so worn that it must be replaced before the other tire has reached its minimum tread depth. If the tires are swapped very early, one of the tires will remain in the more heavily used position significantly longer than the other tire, and the tires will wear out at different times.

[0025] In a step 30, the difference between the expected remaining service life for both tires is therefore minimized.

[0026] In particular, steps 20 and 30 can be carried out by a computing unit of a vehicle in the vehicle itself.

[0027] Fig. 2 shows a vehicle 1 with a front axle 2 and a rear axle 3 and tires 4 arranged thereon. Only individual tires 4 are mounted on the front axle 2, while pairs 5 of tires 4 are mounted on the rear axle 3. This results in the positions 1, 2, 3, and 4 on the rear axle 3. As indicated by the arrows 6, tires 4 can be swapped at the determined optimal time in order to achieve more even wear among each other.

[0028] Fig. Figure 3 shows three diagrams in which the tread depth TD (thread depth) is plotted against the mileage TM (tire mileage) of a tire for two tires at different positions. Fig. Figure 3 illustrates a case in which a change in tire position is carried out early.

[0029] Fig. Figure 3a shows the determined relationship between mileage and tread depth for a tire in a first position (curve k1) and a tire in a second position (curve k2). The minimum tread depth is marked PP (pull point). The time or mileage at which a position change occurs is denoted by T. rot designated.

[0030] Fig. Figure 3b illustrates the further development of the tires after a position change. At time T rot Two tires are swapped. As indicated by arrows 7, the tires are switched to the other corner.

[0031] Fig. Figure 3c shows the difference in the expected remaining service life for both tires resulting from the position change. The difference results from the two mileages at which the curves reach the minimum tread depth PP and is illustrated by shifting the two curves to the zero point of the x-axis. This difference is denoted by Δ.

[0032] Fig. 4 illustrated in the Fig. 4a to 4c analogously show a case in which the position change of tires was carried out late.

[0033] Fig. 5 illustrated in the Fig. 5a to 5c analogously illustrate the case where the position change was performed at the optimal time. The difference Δ is zero here, meaning that both tires in question have reached their minimum tread depth at the same time and must be replaced. List of reference symbols 1 vehicle 2 front axle 3 rear axle 4 tires 5 pairs of tires 6 Arrow 7 Arrow 10 steps 20 steps 30 steps

Claims

[1] Method for determining an optimal time for a change of position of tires (4) of a vehicle (1), comprising - determining a relationship between a mileage and a tread depth for a tire (4) in a first position and a tire (4) in a second position; - Determining an expected remaining service life for both tires (4) depending on a time for a change of position and - Minimizing the difference between the expected remaining service life for both tires (4) depending on the time for a change of position of the tires (4). [2] Method according to claim 1, wherein the method is carried out for a plurality of tire pairs (5) of a vehicle (1). [3] Method according to claim 1 or 2, wherein the relationship between the mileage and the tread depth is determined for a tire (4) in a first position and a tire (4) in a second position by means of test drives. [4] Method according to one of claims 1 to 3, wherein the determination of the relationship between the mileage and the tread depth for a tire (4) in a first position and a tire (4) in a second position is carried out by means of simulations. [5] Method according to claim 3 or 4, wherein the data obtained by test drives and / or simulations are extended by machine learning to previously unincluded routes. [6] Method according to one of claims 1 to 5, wherein the method is carried out during operation of the vehicle (1) by a computing unit arranged in the vehicle (1). [7] A computer program product comprising instructions which, when executed by a computer, cause the computer to carry out the method according to any one of claims 1 to 6. [8] A computer-readable medium comprising instructions which, when executed by a computer, cause the computer to perform the method according to any one of claims 1 to 6.

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