METHOD FOR CONTROLLING THE WHEELS OF A TRAILER COUPLED BY A MOTOR VEHICLE AND SYSTEM IMPLEMENTING SUCH A METHOD

Abstract

The invention relates to a method (100) for steering the wheels (28) of a trailer (16) coupled to a motor vehicle (10), said trailer (16) comprising at least two steerable wheels (28), said method (100) comprising the following steps: – determining (S1) the direction of travel of the vehicle (10) and the inclination of the wheels of the vehicle (10); – determining (S2) the angle of inclination between the vehicle (10) and the trailer; – controlling (S3) the inclination of the wheels of the trailer (16) as a function of the direction of travel of the vehicle (10), the angle of inclination between the vehicle (10) and the trailer (16), and the inclination of the wheels of the vehicle (10). Figure to be published with the abstract: [Fig. 3]

Description

Title of the invention: METHOD FOR CONTROLLING THE WHEELS OF A TRAILER ATTACHED TO A MOTOR VEHICLE AND SYSTEM IMPLEMENTING SUCH A METHOD

[0001] The present invention relates to the field of motor vehicles, and more particularly to the field of motor vehicles towing a trailer and to the means of assisting drivers to maneuver a vehicle-trailer combination.

[0002] It is common for a vehicle to have a tow ball on its rear bumper to which a trailer can be attached. This trailer is generally used to transport goods or objects, but can also be a trailer carrying an external power supply, usually referred to by the Anglo-Saxon term "power bank"; such a trailer typically weighs several hundred kilograms.

[0003] Thus, once coupled, the trailer and the vehicle form a combination whose maneuverability can be difficult, particularly when reversing. More specifically, in the case of small trailers, trailers not equipped with steerable wheels, it is vital to avoid jackknifing the trailer when reversing, as this risks damaging the trailer and / or the vehicle. It is therefore necessary to find a solution that simplifies the use of such trailers.

[0004] The present invention thus aims to remedy at least one of the aforementioned drawbacks by proposing a new type of method for steering the wheels of a trailer coupled to a motor vehicle, said trailer comprising at least two steerable wheels, said method comprising the following steps: - determining the direction of travel of the vehicle and the inclination of the vehicle's wheels; - determination of the angle of inclination between the vehicle and the trailer; - control of the trailer wheel tilt according to the direction of travel of the vehicle, the angle of inclination between the vehicle and the trailer and the inclination of the vehicle's wheels.

[0005] The method according to the invention thus proposes a simple method to assist in driving and promote the maneuverability of a vehicle to which a trailer with steerable wheels is attached.

[0006] According to one possible feature, if the vehicle is moving forward, the control of the trailer wheel tilt is achieved by determining the instantaneous center of rotation of the vehicle, and then by tilting the trailer wheels in the same direction as the vehicle's wheels, so that the trailer and the vehicle have substantially the same instantaneous center of rotation.

[0007] The method according to the invention allows, when the vehicle is moving forward, the wheels of the trailer to be oriented angularly in substantially the same way as the wheels of the vehicle, in order to avoid causing lateral inertia of the trailer that could destabilize the vehicle-trailer combination and lead to an accident. It should be noted that such control of the trailer's wheel inclination is advantageously applied at low speeds, for example, at speeds below a few tens of kilometers per hour, and is preferably activated (or validated) beforehand by the operator of the vehicle towing the trailer.

[0008] According to another possible feature, the trailer wheel tilt control is triggered if the vehicle speed exceeds a predetermined value, for example a speed greater than or equal to 80 km / h. Advantageously, the process is triggered when the vehicle exceeds a predetermined speed, for example a speed from which lateral inertial forces during a turn can cause problems in the driving of the vehicle-trailer combination.

[0009] According to another possible feature, there is control of the inclination of the trailer wheels so that the trailer wheels are oriented substantially parallel to the longitudinal axis of the vehicle and that said wheels are angularly locked if the vehicle has a non-zero speed, but less than a predetermined value, for example a speed greater than 5-10 km / h and less than 80 km / h. Advantageously, the wheels of the trailer do not orient themselves in the same way as the wheels of the vehicle at low speed, that is to say for a non-zero speed and less than a predetermined speed value, but said wheels have a zero angle, as long as the lateral inertial forces remain low for the vehicle-trailer assembly, especially in turns.

[0010] According to another possible feature, if the vehicle is stationary, but the vehicle is engaged in a forward gear, the inclination of the trailer wheels is controlled in the same direction as the vehicle wheels so that the trailer and the vehicle have the same instantaneous center of rotation. Advantageously, after the vehicle has started, but before the vehicle starts moving, the method according to the invention orients the trailer wheels at a zero angle, in order to facilitate the maneuverability of the vehicle-trailer combination, for example when exiting a parking space.

[0011] According to another possible feature, if the vehicle is reversing, the control of the trailer wheel tilt is achieved by determining the center of instantaneous rotation of the vehicle, then by tilting the wheels of the trailer in the opposite direction to the wheels of the vehicle, so that the trailer and the vehicle have the same center of instantaneous rotation. The method according to the invention is advantageously configured to orient the wheels of the trailer angularly during reversing, for example when the vehicle-trailer combination parks in a parking space, and thus optimize the behavior of the trailer and facilitate the maneuver to be carried out by the driver of the vehicle.

[0012] According to another possible feature, if the vehicle is in neutral, the inclination of the trailer wheels is controlled so that the trailer wheels are substantially aligned with the longitudinal axis of the vehicle. The method according to the invention is advantageously configured to align the wheels along the longitudinal axis of the vehicle, in order to facilitate departure and / or when the assembly is parked, the wheels of the vehicle and the trailer must be straight, so as not to create obstacles for third parties.

[0013] According to another possible feature, said method comprises, prior to said control of the inclination of the trailer wheels, one or more of the following steps: - determination of the speed of the vehicle and / or trailer; - determination of the distance between the front and rear wheels of the vehicle; the control of the trailer wheel tilt is also a function of the speed of the vehicle and / or the trailer and / or the distance between the front and rear wheels of the vehicle. Advantageously, wheel tilt control can also depend on additional parameters, such as the speed of the vehicle and / or trailer, and / or the distance between the front and rear wheels of the vehicle.

[0014] The invention also relates to a wheel steering system for a trailer attached to a motor vehicle, characterized in that said system is configured to implement the method as defined above.

[0015] According to one possible feature, said system includes a tilt angle sensor between the vehicle and the trailer or a camera configured to determine the angle between the vehicle and the trailer.

[0016] According to one possible feature, said system includes a human-machine interface through which the vehicle user can activate, deactivate or configure said process. Advantageously, the system enabling the implementation of the trailer wheel steering process can be activated and deactivated by the vehicle user, by means of a human-machine interface located in the cab of the vehicle, or be configured according to the user's expectations, meaning that all or part of the process can be activated or not, for example based on vehicle speed values ​​determined by the user.

[0017] The invention further relates to a vehicle-trailer assembly, characterized in that said assembly comprises a system as defined above.

[0018] The invention will be better understood, and other objects, details, features and advantages thereof will become more apparent from the following description of a particular embodiment of the invention, given solely by way of illustration and not limitation, with reference to the accompanying drawings, in which: - Fig. 1 illustrates a very schematic, partial and side view of a trailer coupled to a vehicle forming a vehicle-trailer combination according to the invention; - [Fig.2] is a very schematic, partial and bottom view of the vehicle-trailer assembly of [Fig.1]; - [Fig.3] is a logic diagram illustrating a control method according to the invention of the wheels of the trailer of the set of [Fig.1] and [Fig.2].

[0019] In the following description, the term "include" is synonymous with "include" and is not limiting in that it permits the presence of other elements in the vehicle, or the structure to which it relates. It is understood that the term "include" includes the terms "consist of".

[0020] Similarly, the terms "lower," "upper," "front," "rear," "longitudinal," and "transverse" shall be understood in relation to the general orientation of the motor vehicle and / or trailer, unless otherwise specified in the context or indicated. Furthermore, it should be noted that in the various figures, the same reference numerals designate identical or similar elements.

[0021] In this application, it should be noted that "substantially parallel" means a direction deviating by no more than 20°, or even by no more than 10° or 5°, from a parallel direction. It should also be noted that "substantially orthogonal" means a direction deviating by no more than 20°, or even by no more than 10° or 5°, from an angle of 90°.

[0022] Furthermore, an orthogonal frame XYZ can be defined with respect to the vehicle or trailer, namely: - an X-axis, defining a longitudinal and horizontal direction of the vehicle, - a Y-axis, defining a transverse and horizontal direction, which together with the X-axis defines a horizontal XY plane, - a Z axis, defining a vertical direction, orthogonal to the horizontal XY plane, the Z axis with the X axis defining a vertical XZ plane.

[0023] Fig. 1 thus illustrates a schematic, partial and side view of a motor vehicle 10 to which a trailer 16 is attached, the vehicle 10 and the trailer 16 thus forming a vehicle-trailer combination 10 and 16.

[0024] The motor vehicle 10 includes a coupling system 12, also referred to as a towing system, which comprises a tow hook 14 surmounted by a tow ball. Such a coupling system 12 is thus configured to tow the trailer 16 forming an auxiliary vehicle, or towed vehicle, while the motor vehicle 10 is the towing vehicle.

[0025] The trailer 16 includes, for example, an electric battery 24. The electric battery 24 is advantageously connected to the motor vehicle 10 and acts as an external electric battery for the vehicle 10. The electric battery 24 has a capacity of at least 5 kWh, preferably at least 20 kWh, and even more preferably at least 50 kWh. The electric battery 24 of the trailer 16 increases the driving range of the motor vehicle 10 when the latter is an electric or hybrid vehicle.

[0026] Furthermore, the trailer 16 includes a coupling device 18 with a coupling head 20. The coupling head 20 is configured to be coupled to the tow hook 14 of the vehicle 10, by being fitted onto the tow ball. The coupling head 20 has, for example, an inverted cup shape, open at the bottom, with the tow ball fitting into said cup (when the trailer is coupled to the vehicle).

[0027] Thus, when the coupling head 20 and the coupling system 12 are coupled, these 12 and 20 form a mechanical link, the trailer 16 being able to pivot relative to the vehicle 10 along a substantially vertical pivoting axis passing through said mechanical link.

[0028] The trailer 16 further includes a chassis 22 which forms the load-bearing structure of the trailer 16. The chassis 22 is thus configured to accommodate a load in the trailer 16, such as the battery 24.

[0029] Furthermore, said trailer 16 includes steerable wheels 28, for example connected together, said steerable wheels 28 then forming an axle, as well as a steering system 26 for said steerable wheels 28. The steerable wheels 28 can be oriented pivotally relative to the chassis 22 along vertical pivot axes 30 (axes substantially parallel to the Z axis).

[0030] The steerable wheels 28 are therefore able to rotate (on themselves) around their horizontal axis of rotation, and to pivot around their vertical directional axis 30, which also form directional pivot axes.

[0031] Fig. 2 is, for its part, a schematic, partial, and bottom view of the vehicle-trailer assembly 10 and 16, the trailer 16 being attached to the vehicle 10.

[0032] It will be noted that the vehicle-trailer assembly 10 and 16 is represented during a reversing maneuver, with the motor vehicle 10 pushing the trailer 16 in a reverse curve.

[0033] Due to the curve, the trailer 16 pivots at an angle of inclination 34 relative to the motor vehicle 10. The angle of inclination is the angle between the longitudinal axes 36 of the trailer 16 and the motor vehicle 10.

[0034] It should also be noted that the steerable wheels 28 include rotation axes 44. The rotation axes 44 are substantially horizontal, and perpendicular to the vertical directional axes 30.

[0035] The control system 26 includes an actuator 40 and a control module 42 configured to control the actuator 40. The control system 26 is thus configured to orient the steerable wheels 28 via the actuator 40 according to the commands sent by said module 42.

[0036] It should be noted that the actuator 40 and / or the control module 42 are, for example powered by a battery from the motor vehicle 10 and / or by the battery 24 from the trailer 16.

[0037] In addition, the control module 42 is configured to: - determine the angle of inclination 34, whether by communication, reading, calculation and / or via a suitable sensor (for example an angular sensor housed in the head or coupling system, or a camera configured to determine this angle), i.e. the angle between the longitudinal axes 36 of the trailer 16 and the motor vehicle 10; - determine the direction of travel of vehicle 10 and the angle of inclination of the wheels of vehicle 10 whether by communication with an on-board computer of vehicle 10, reading, calculation and / or via one or more suitable sensors.

[0038] Thus, when turning, the motor vehicle 10 rotates around an instantaneous center of rotation 38. The position of the instantaneous center of rotation 38 is, for example, determined by the on-board computer of the motor vehicle 10 according to the orientations of its wheels or by the control module 42 of the trailer 16. The instantaneous center of rotation 38 can be defined in an environmental reference frame or a reference frame of the motor vehicle 10.

[0039] The steering system 26 is further configured to implement a steering method 100 according to the invention of the wheels of the trailer 10 coupled to the vehicle 16, method 100 illustrated in the form of a logic diagram in [Fig.3].

[0040] The process 100 thus comprises at least the following steps: - determining the direction of travel of the vehicle and the inclination of the vehicle's wheels, that is to say whether the vehicle is moving or will move forwards or backwards; - determination S2 of the angle of inclination 34 between the vehicle 10 and the trailer 16, for example by means of an angle sensor or a camera; - S3 control of the inclination of the wheels 28 of the trailer 16 according to the direction of travel of the vehicle, the angle of inclination 34 between the vehicle 10 and the trailer 16 and the inclination of the wheels of the vehicle 10.

[0041] The determination Si of the direction of travel of the vehicle and the inclination of the vehicle's wheels is carried out by means of the control module 42 which is connected to the vehicle's on-board computer 10, the latter sending the information to said module 42, and / or by means of suitable sensors communicating with said module 42.

[0042] Thus, if it is determined that the vehicle 10 is moving forward, the S3 control of the inclination of the wheels 28 of the trailer 16 can be carried out according to different modalities listed below.

[0043] If the speed of the vehicle exceeds a predetermined value, for example a speed greater than or equal to 80 km / h, the control S3 of the inclination of the wheels 28 of the trailer 16 is carried out after the determination S4 of the instantaneous center of rotation 38 of the vehicle 10, then by inclining the wheels 28 of the trailer in the same direction as the wheels of the vehicle 28, so that the trailer 10 and the vehicle 16 have the same instantaneous center of rotation 38.

[0044] Furthermore, if the vehicle has a non-zero speed, but less than a predetermined value, identical or different from the previous predetermined value, for example a speed greater than 5 km / h and less than 80 km / h, there is tilting of the wheels 28 of the trailer 16 so that said wheels 28 of the trailer 16 are oriented substantially parallel to the longitudinal axis 36 of the vehicle 10 and that said wheels 28 of the trailer 16 are then angularly locked.

[0045] Furthermore, if the vehicle speed is zero, i.e., at rest, but the vehicle is engaged in a forward gear, the inclination of the wheels 28 of the trailer 16 is controlled in the same direction as the wheels of the vehicle 10 so that the trailer 16 and the vehicle 10 have the same instantaneous center of rotation 38.

[0046] However, if it is determined that the vehicle 10 is in reverse, the control S3 of the tilt of the wheels 28 of the trailer 16 is carried out after the determination S4 of the instantaneous center of rotation 38 of the vehicle 10, then by tilting the wheels 28 of the trailer 16 in the opposite direction to the wheels of the vehicle 10, so that the trailer 16 and the vehicle 10 have the same instantaneous center of rotation 38.

[0047] Finally, if it is determined that the vehicle is in neutral, then there is S3 control of the inclination of the wheels 28 of the trailer 16 so that the wheels 28 of the trailer 16 present an angle substantially parallel to the longitudinal axis 36 of the vehicle 10.

[0048] In addition, the method 100 may include a step (not illustrated) for aligning the wheels 28 of the trailer with the longitudinal axis 36 of the vehicle 10 when the vehicle-trailer assembly 10 and 16 is parked, in order to facilitate departure and / or to better stabilize the assembly 10 and 16 in the parking position.

[0049] Furthermore, the control system 26 advantageously includes a human-machine interface (not shown) through which the user of the vehicle 10 can activate, deactivate or configure said process 100 implemented by the control system 26.

[0050] The term "parameterizing" said process 100 means activating all or part of the process 100, and / or adjusting the vehicle speed values ​​for which the process 100 modifies the inclination (or angular orientation) of the wheels 28 of the trailer 16.

[0051] It will also be noted that the control system 26 is configured to determine an instantaneous center of rotation position 38 of the vehicle 10, either by calculation (using the control module) from the angle of inclination of the wheels of the vehicle 10 (information obtained by communication with the vehicle's on-board computer or by means of suitable sensors), or by direct communication of the position of the instantaneous center of rotation 38 from the vehicle's on-board computer 10.

[0052] Thus, when steering the wheels 28, the steering system 26 controls the actuator 40 so that the axes of rotation 44 of the steering wheels 28 cross at the instantaneous center of rotation 38 according to the angle of inclination 34, in the same direction when the vehicle 10 is moving forward, in the opposite direction when the vehicle is moving backward.

[0053] It should also be noted that the determination of the angle of inclination of the wheels 28 of the trailer 10 can be carried out by means of calculations carried out by the control module 42 and which can be based on average geometric data, or real data retrieved from a memory, or provided by a user, relating to the trailer 16 and / or the vehicle 10, such as the length of the vehicle and / or the trailer, the distance between the wheels of the trailer 16 and the vehicle 10, etc.

[0054] In another, unrepresented embodiment of the method according to the invention, said method comprises, prior to said control of the inclination of the trailer wheels, one or more of the following steps: - determination of the speed of the vehicle and / or trailer; - determination of the distance between the front and rear wheels of the vehicle; the control of the inclination of the trailer wheels is also a function of the speed of the vehicle and / or the trailer and / or the distance between the front and rear wheels of the vehicle (therefore in addition to the parameters previously stated).

[0055] Thus, in this embodiment, the determination of: - the speed of the vehicle and / or trailer can be determined by communication with an on-board computer of the vehicle, reading, calculation and / or via one or more suitable sensors; - the determination of the distance between the front and rear wheels of the vehicle can be carried out by communication with an on-board computer of the vehicle 10, reading, calculation, via one or more suitable sensors, and / or by input of a value into said system via the machine interface.

[0056] Furthermore, if the distance between the front and rear wheels of the vehicle is determined by said system, then this distance is advantageously used during the step of determining the instantaneous center of rotation of the vehicle.

[0057] In an unrepresented embodiment of the invention, the trailer comprises several axles, including a rear axle, for example with steerable wheels or wheels with fixed orientation.

[0058] In another unrepresented embodiment of the invention, the steering system actuator comprises a cylinder, for example electric or hydraulic.

[0059] In another unrepresented embodiment of the invention, the trailer is a loading trailer or a caravan.

Claims

Demands

1. Method (100) of steering the wheels (28) of a trailer (16) coupled to a motor vehicle (10), said trailer (16) comprising at least two steerable wheels (28), said method (100) comprising the following steps: - determination (S1) of the direction of travel of the vehicle (10) and of the inclination of the wheels of the vehicle (10); - determination (S2) of the angle of inclination between the vehicle (10) and the trailer; - steering (S3) the inclination of the wheels of the trailer (16) as a function of the direction of travel of the vehicle (10), the angle of inclination between the vehicle (10) and the trailer (16) and the inclination of the wheels of the vehicle (10).

2. Method (100) according to the preceding claim, characterized in that, if the vehicle (10) is moving forward, the control (S3) of the inclination of the wheels (28) of the trailer (16) is achieved by determining (S4) the instantaneous center of rotation (44) of the vehicle (10), then by inclining the wheels (28) of the trailer in the same direction as the wheels of the vehicle (10), so that the trailer (16) and the vehicle (10) have substantially the same instantaneous center of rotation (44).

3. Method (100) according to the preceding claim, characterized in that the steering (S3) of the inclination of the wheels (28) of the trailer (16) is triggered if the speed of the vehicle (10) exceeds a predetermined value.

4. Method (100) according to claim 2, characterized in that there is piloting (S3) of the inclination of the wheels (28) of the trailer (16) so that the wheels (28) of the trailer (16) are oriented substantially parallel to the longitudinal axis of the vehicle (10) and that said wheels (28) are angularly locked if the vehicle (10) has a non-zero speed, but less than a predetermined value.

5. Method (100) according to claim 2, characterized in that, if the vehicle (10) is at rest, but the vehicle is engaged in a forward gear, there is piloting (S3) of the inclination of the wheels (28) of the trailer (16) in the same direction as the wheels of the vehicle (10) so that the trailer (16) and the vehicle (16) have the same instantaneous center of rotation (44).

6. Method (100) according to any one of the preceding claims, characterized in that, if the vehicle (10) is in reverse, the control (S3) of the inclination of the wheels (28) of the trailer (16) is achieved by determining (S4) the instantaneous center of rotation (44) of the vehicle (10), then by inclining the wheels (28) of the trailer (16) in the opposite direction to the wheels of the vehicle (10), so that the trailer (16) and the vehicle (10) have the same instantaneous center of rotation (44).

7. Method (100) according to the preceding claim, characterized in that, if the vehicle (10) is in neutral, there is piloting (S3) of the inclination of the wheels (28) of the trailer (16) so that the wheels (28) of the trailer are substantially aligned with the longitudinal axis (36) of the vehicle (10).

8. Method (100) according to the preceding claim, characterized in that said method (100) comprises, prior to said control (S3) of the inclination of the wheels (28) of the trailer (16), one or more of the following steps: - determination of the speed of the vehicle (10) and / or of the trailer (16); - determination of the distance between the front and rear wheels of the vehicle (10); the control (S3) of the inclination of the wheels (28) of the trailer (16) also being a function of the speed of the vehicle (10) and / or of the trailer (16), and / or of the distance between the front and rear wheels of the vehicle (10).

9. A steering system (26) for the wheels of a trailer for a trailer coupled to a motor vehicle, characterized in that said system (26) is configured to implement the method (100) according to any one of the preceding claims

10. Vehicle-trailer assembly (10, 16), characterized in that said assembly (10, 16) comprises a system (26) according to the preceding claim.

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