Device and method for checking the condition of a motor vehicle tire

Abstract

A tire inspection system for a motor vehicle (1) comprises: a bracket adapted for mounting in a vehicle fender partially surrounding the tire; on which is mounted at least one camera oriented towards the tire; the camera being connected to a comparator (51) of a tire profile constructed from an image taken by the camera with a reference tire profile; and said comparator is connected to an alarm transmitter (55) adapted to send an alarm when the comparison reveals an anomaly. Figure to be published with the abbreviation: Fig. 1

Description

Title of the invention: Device and method for checking the condition of a motor vehicle tire technical field

[0001] The present invention relates to a device and a method for checking the condition of a tire of a motor vehicle. State of the art

[0002] Tires are essential safety components of a motor vehicle because they provide the contact with the road surface. An anomaly in tire wear, balance, or geometry will impact the longitudinal or lateral grip that the tire can develop and the overall road holding.

[0003] More specifically, the anomalies of a tire relate to its wear, balance and geometry, or parallelism.

[0004] Thus, wear control will examine the remaining thickness, which must be greater than the legal minimum (1.6 mm in France) and uniform. Furthermore, wear can manifest as aging phenomena or cracking of the tread or sidewall rubber, which may indicate carcass deformation. Moreover, uneven tire wear is often an indication of suboptimal operating conditions, such as incorrect inflation pressure or suspension geometry abnormalities (e.g., incorrect toe and / or camber angles).

[0005] The lack of balance results in a non-uniform distribution of masses around the rim.

[0006] And the geometry problems result in wheels that are not parallel to each other or to the axis of the road.

[0007] Almost all of these problems will result in modifications to the tire profile over the entire circumference of its tread compared to a reference profile corresponding to a healthy tire.

[0008] However, this analysis usually requires complete disassembly of the wheel and testing on a measuring bench.

[0009] This operation requires time and the expertise of a specialist. Consequently, drivers only perform this operation when a problem arises: instability in vehicle handling, unusual noises, or a major visual anomaly detectable to the naked eye. And sometimes, due to insufficient warning signs, an accident occurs because the driver loses control of the vehicle (tire blowout, loss of traction, etc.).

[0010] There is therefore a real need for a device and a method for checking tires that resolves all or part of these drawbacks, in particular ones that allow for regular checks throughout the tire's lifespan. Description of the invention

[0011] To overcome one or more of the aforementioned drawbacks, according to a first embodiment, a tire verification system for a motor vehicle comprises: • a suitable bracket for attaching to a vehicle's mudguard that partially surrounds the tire; onto which is attached • at least one camera pointed towards the tire; the camera being connected to • a comparator of a tire profile constructed from an image taken by the camera with a reference tire profile; and said comparator is connected to • an alarm transmitter suitable for sending an alarm when the comparison reveals an anomaly.

[0012] Thus, this allows for regular diagnosis of the condition of the tire and informs the driver as soon as an anomaly is detected.

[0013] Specific features or embodiments, usable alone or in combination, are: • It includes 3 cameras oriented to capture images of the tread and both sidewalls of the tire; • The mount includes a telescopic extension comprising one of the three cameras, the telescopic extension being such that, when the mount is fixed in the fender, the telescopic extension includes a first folded position such that the telescopic extension does not protrude from the side of the automobile and an unfolded position such that the telescopic extension protrudes from the side of the automobile and its camera is in position to take an image of the outer side of the tire; • The mount includes a camera protection cover; • The comparator includes a profile generator adapted to generate the three-dimensional profile of the tire while the vehicle is moving; • The anomaly is a wear anomaly, a balancing anomaly and / or a geometry anomaly; and / or • The reference profile is constructed from an image of a new tire.

[0014] In a second embodiment, a motor vehicle includes a system as described above.

[0015] In a third embodiment, a method for checking a tire of a motor vehicle comprises: • fix a camera in a mudguard of the vehicle; • take a picture of the tire with the camera; • compare a tire profile constructed from the image taken by the camera with a reference tire profile; • generate an alarm when the comparison reveals an anomaly.

[0016] In a fourth embodiment, a computer program product downloadable from a communication network and / or stored on a computer-readable medium and / or executable by a processor, includes program code instructions for implementing the above method. Brief description of the figures

[0017] The invention will be better understood upon reading the following description. This description should be considered illustrative and given by way of example and not as limiting the invention to this single description made with reference to the figures in the appendix in which: • [Fig.1] represents an exploded top view of a vehicle comprising a verification system according to one embodiment; • [Fig.2] represents a device in unfolded mode of the verification system of the [Fig.1]; • [Fig.3] represents the device of [Fig.2] in folded mode; • [Fig.4] shows the device of [Fig.2] fixed in the front mudguard left side of the vehicle; • [Fig. 5] represents a block diagram of the functions of the verification system; and • [Fig.6] represents a flowchart of the verification process according to one embodiment. Methods of implementation

[0018] The embodiments presented below refer to a motor vehicle, a car. However, those skilled in the art understand that they are also applicable to other types of vehicles such as vans, trucks, etc.

[0019] The terms "front", "rear", "top", "bottom", "side", etc. are understood in relation to the vehicle.

[0020] With reference to [Fig.1], a vehicle 1 comprises 4 camera devices 3, 5, 7, 9 fixed in the fenders of the vehicle 1, which is symbolized by the exploded top view, with the wheels outside the vehicle.

[0021] The cameras of these devices are connected to a computer 11 which is itself connected to a display 13 on the dashboard of the vehicle.

[0022] The 4 devices 3, 5, 7, 9 are identical.

[0023] Fig. 2 is an isometric view of device 3, for example, in operation.

[0024] The device 3 includes a support 21 adapted to be fixed in a mudguard of the vehicle 1.

[0025] At one end of the support 21, a telescopic extension 23 includes a camera 25. The telescopic extension is shown in the extended position. It can move between this position and a folded position where it is contained almost entirely within the support 21.

[0026] The support also includes two cameras 27, 29.

[0027] Figure 3 shows the same device 3, but in the folded position. The extension 23 is retracted into the support 21 and the cameras 27, 29 are protected by shutters 31, 33.

[0028] Fig. 4 represents the device 3 installed in the mudguard 41 of the vehicle 1. More specifically, the figure represents the front left wheel 43 seen from the left side of the vehicle 1, approximately at the height of the driver's door.

[0029] The device 3 is in the active position, with the telescopic extension 21 unfolded. Thus, the 3 cameras 25, 27, 29 can take images respectively of the outer sidewall of the wheel 43 tire, its tread and its inner sidewall.

[0030] As shown in the figure, the telescopic extension 23 protrudes from the sidewall of the vehicle 1 when in the extended position, allowing it to take images of the outer sidewall of the tire. However, this protrusion has the disadvantage of exposing the device to impact from an external object and negatively affecting the aerodynamics of the vehicle 1. The folded position, when the device is not in operation, protects it and thus eliminates these disadvantages.

[0031] Cameras 25, 27 and 29 are therefore connected to computer 11.

[0032] The calculator 11 includes, [Fig.5], a profile comparator 51 itself comprising a profile generator 53.

[0033] The profile generator 53 constructs a tire profile from images taken by the cameras. More specifically, the cameras take a series of photos while the wheel rotates at low speed for at least one complete wheel rotation, for example, when starting the vehicle, so as to obtain photos of the entire tire. These photos are then consolidated by the profile generator 53 into a complete 3D profile of the tire.

[0034] The profile comparator 51 then compares the profile obtained with a reference profile.

[0035] The reference profile corresponds to the profile of a tire without defects. For example, it could be a profile created by the profile generator during an initialization phase with new tires rolling on a flat surface.

[0036] If, during this comparison, comparator 51 detects a significant difference of an anomaly, it sends an alarm signal to the display 13 via the alarm transmitter 55.

[0037] For example, if the comparison shows a localized bulge on the sidewall of the tire, this may indicate the presence of a bulge. The warning message will then display a message such as "Front left tire: lateral bulge on the outer sidewall".

[0038] The system thus described then implements the following verification procedure, [Fig.6]: • fix, step 61, in a mudguard of the vehicle, a camera; • Take, step 63, an image of the tire with the camera; • compare, step 65, a tire profile constructed from the image taken by the camera with a reference tire profile; • generate, step 67, an alarm when the comparison reveals an anomaly.

[0039] Many variations of this embodiment are possible.

[0040] For example, the calculator can be distributed across the 4 devices or the display can be replaced, or supplemented, by an audible alarm device.

[0041] The reference 3D profile can be downloaded from a centralized database, managed for example by the vehicle manufacturer, each profile being associated with a type of tire and a type of vehicle.

[0042] Figures 1 and 5 illustrate a system according to certain embodiments. The breakdown presented is for pedagogical purposes to highlight the different functions. However, it is understood that each block can be implemented using different means or combinations thereof, such as hardware components, software, one or more computers, and / or electronic circuits. Each component may include at least one computer or a control unit. At least one memory may be included in each component. The memory may include computer program instructions or software code.

[0043] The computers can be implemented by any type of data processing device, such as a central processing unit, a signal processing unit, a specific application integrated circuit, a programmable gate network, etc. The computers can be implemented in the form of a single controller, or a plurality of controllers or computers.

[0044] The various modules are connected to each other by data links adapted to the environment. These can be wired or wireless. For example, the Data transfer between the different elements is carried out by a CAN type data bus (for "Controller Area Network" in English, or "controller area network") or LIN (for "Local Interconnect Network" in English, or "Local interconnected network" in French).

[0045] For the software, the implementation may comprise modules or units distributed in the form of procedures, functions, etc. The memories may be any type of storage circuit. They may be part of the processor circuit, or separate from it and connected via electrical data links. These may be non-volatile memories, hard drives, RAM, flash memory, etc.

[0046] Furthermore, the program instructions stored in memory and processed by the computers can be any type of program code, for example, a compiled or interpreted program written in a suitable programming language.

[0047] The computer program instructions stored in memory are such that, when executed by the computer, the latter carries out one or more of the steps of the processes described above.

Claims

Demands

1. A system for verifying a tire of a motor vehicle (1) comprising: • a support (21) adapted to be fixed in a mudguard of the vehicle partially surrounding the tire; on which is fixed • at least one camera (23, 25, 27) directed towards the tire; the camera being connected to • a comparator (51) of a tire profile constructed from an image taken by the camera with a reference tire profile;and said comparator is connected to • an alarm transmitter (55) adapted to send an alarm when the comparison reveals an anomaly, characterized in that it comprises 3 cameras (23, 25, 27) oriented to image the tread and both sides of the tire, the support comprising a telescopic extension (23) comprising one of the three cameras, the telescopic extension being such that, when the support is fixed in the fender, the telescopic extension comprises a first folded position such that the telescopic extension does not protrude from the side of the car and an unfolded position such that the telescopic extension protrudes from the side of the car and its camera is in position to image the outer side of the tire.;

2. System according to claim 1, characterized in that the support includes a camera protection flap.

3. System according to any one of claims 1 or 2, characterized in that the comparator (51) includes a profile generator (53) adapted to generate the three-dimensional profile of the tire when the vehicle is moving.

4. System according to any one of claims 1 to 3, characterized in that the anomaly is a wear anomaly, a balancing anomaly and / or a geometry anomaly.

5. System according to any one of claims 1 to 4, characterized in that the reference profile is constructed from an image of a new tire.

6. Motor vehicle comprising a system according to any one of claims 1 to 5.

7. A method for checking a tire of a motor vehicle characterized in that it comprises: • fixing (61) in a mudguard of the vehicle, a camera; • taking (63) an image of the tire with the camera; • comparing (65) a profile of the tire constructed from the image taken by the camera with a reference tire profile; • generating (67) an alarm when the comparison reveals an anomaly, the method being implemented by a system according to any one of claims 1 to 5.

8. Product computer program downloadable from a communication network and / or recorded on a computer-readable medium and / or executable by a processor, characterized in that it includes program code instructions for implementing the method according to claim 7.