Vehicle and associated control method for controlling torque distribution when instabilities are present

Abstract

The invention relates to a land vehicle (V) comprising: - a first prime mover (MM1) and a second prime mover (MM2) providing torque to a first axle (T1) and to a second axle (T2) which are wheels, - a braking system (SF) acting on said wheels, - a supervisory computer (CS) controlling the torque distribution between said first axle (T1) and said second axle (T2), and - a trajectory control device (DCT) for, in the event of detection of instability of said vehicle (V), commanding said supervisory computer (CS) to leave the current torque distribution as it is and controlling said braking system (SF) until said instability disappears, then authorizing said supervisory computer (CS) to perform a modification of said torque distribution.

Description

Technical Field

[0001] This invention claims priority to French application No. 1913883, filed on December 6, 2019, the contents of which (text, drawings and claims) are incorporated herein by reference.

[0002] The present invention relates to land vehicles (in which torque generated by a powertrain (or GMP) can be distributed between two axles driving the wheels), and more precisely to the control of such torque distribution. Background Technology

[0003] Some land vehicles include a powertrain (or GMP) that includes a first prime mover and a second prime mover that provide torque to a first axle and a second axle respectively (driving) the wheels, a monitoring computer that controls the torque distribution between the first axle and the second axle, a braking system that acts on the wheels, and at least a trajectory control device that controls the braking system.

[0004] The trajectory control device is responsible for intervening whenever instability of the vehicle is detected by selectively acting on the sub-sections of the braking system associated with different drive wheels, and optionally on one of the prime movers and / or the gear shifting device. Such a trajectory control device may be dedicated to anti-slip (therefore commonly referred to as ESP (“Electronic Stability Program”) or ESC (“Electronic Stability Control”) or dedicated to anti-skid (therefore commonly referred to as ASR (“Accélération Slip Régulation”) or TCS (“Traction Control System”).

[0005] When the monitoring computer decides to modify the torque distribution between the first and second axles, this can sometimes lead to instability in the vehicle, which the trajectory control device must eliminate. In fact, a wheel on one of the axles may slip, and the modification of the torque distribution can cause a significant increase in the rotational speed of the wheels on the other axles. In this situation, the trajectory control device first corrects the slippage on one of the axles relatively quickly, and then attempts to correct the significant increase on the other axles (when there is torque transfer or distribution modification), which typically takes longer due to cumulative delays.

[0006] A similar problem can occur even if the vehicle has already experienced instability, when the monitoring computer decides to modify the torque distribution between the first and second axles.

[0007] Currently, optimizations for torque distribution between the first and second axles have been provided, particularly in patent documents FR-B1 2980408 and FR-A1 3078304, or FR-A1-2955533 and JP-A1-2008120119. However, these optimizations are generally solely aimed at minimizing fuel consumption to limit pollutant emissions and CO2 production, and do not control the torque distribution when vehicle instability exists.

[0008] Therefore, the object of the present invention is particularly to improve the situation described above. Summary of the Invention

[0009] Therefore, the present invention provides a land vehicle that includes at least a first prime mover providing torque to a first axle of the wheels, a second prime mover providing torque to a second axle of the wheels, a braking system acting on the wheels, a monitoring computer controlling the torque distribution between the first and second axles, and a trajectory control device controlling the braking system.

[0010] The land vehicle is characterized in that, upon detecting instability in the vehicle, the trajectory control device commands the monitoring computer to maintain the current torque distribution as is, and controls the braking system until the instability disappears, and then authorizes the monitoring computer to perform modifications to the torque distribution.

[0011] Because of this invention, the trajectory control device can operate in real time, and detected instabilities will not be modified by the torque distribution determined by the monitoring computer.

[0012] The land vehicle according to the invention may include other features that may be used individually or in combination, in particular:

[0013] When instability of the vehicle is detected after the current modification of the torque distribution, the trajectory control device can determine whether the modification can continue. If not, the trajectory control device can instruct the monitoring computer to maintain the current torque distribution as is. If yes, the trajectory control device can determine a value characterizing further modifications based on the estimated changes in grip between the wheels, and then instruct the monitoring computer to create a modification of the current torque distribution defined by the determined value. Similarly, in the negative case, the trajectory control device can control the braking system until the instability disappears.

[0014] When instability of the vehicle is detected without any modification to the current torque distribution, the trajectory control device may command the monitoring computer to maintain the current torque distribution and control the braking system until the instability disappears, and then authorize the monitoring computer to perform a modification to the current torque distribution;

[0015] -The first prime mover can be a heat engine;

[0016] -The land vehicle may include a third prime mover that provides torque to the first axle of the wheels;

[0017] - The third prime mover can be an electric motor powered by a rechargeable battery;

[0018] - The second prime mover can be an electric motor powered by a rechargeable battery;

[0019] - The land vehicle may be of a motorized type.

[0020] The present invention also provides a control method for implementation in a land vehicle, the land vehicle including at least a first prime mover providing torque to a first axle of the wheels, a second prime mover providing torque to a second axle of the wheels, a braking system acting on the wheels, a monitoring computer controlling the torque distribution between the first and second axles, and a trajectory control device controlling the braking system.

[0021] The control method is characterized by comprising the steps of, in the event of detecting instability in the vehicle, the trajectory control device instructs the monitoring computer to maintain the current torque distribution in its original state and controls the braking system until the instability disappears, and then authorizes the monitoring computer to perform modifications to the torque distribution.

[0022] The present invention also provides a computer program product comprising a set of instructions that, when executed by a processing unit, implement a control method of the type described above to control torque distribution between a first axle and a second axle of a wheel of a land vehicle, the land vehicle comprising at least a first prime mover providing torque to the first axle, a second prime mover providing torque to the second axle, a braking system acting on the wheel, a monitoring computer for controlling the torque distribution, and a trajectory control device for controlling the braking system. Attached Figure Description

[0023] Other features and advantages of the invention will become more apparent from the following detailed description and accompanying drawings, in which:

[0024] - Figure 1A top view of an embodiment of a land vehicle according to the present invention is shown schematically and functionally.

[0025] - Figure 2 An embodiment of the trajectory control device is illustrated schematically and functionally, and

[0026] - Figure 3 The upper section schematically illustrates a first graph example showing the evolution of the torque (c1) requested by the driver, the torque on the front axle (c2) without the invention, the torque on the rear axle (c3) without the invention, the torque on the front axle (c4) with the invention, and the torque on the rear axle (c5) with the invention over time. The lower section schematically illustrates a first graph example showing the evolution of the vehicle speed (c6), the speed of the front wheels (c7) without the invention, the speed of the rear wheels (c8) without the invention, the speed of the front wheels (c9) with the invention, and the speed of the rear wheels (c10) with the invention over time. These first graph examples are under the conditions defined by the first graph examples.

[0027] - Figure 4 The upper section schematically illustrates second graph examples showing the time evolution of the torque requested by the driver (c1'), the torque on the front axle (c2') without the invention, the torque on the rear axle (c3') without the invention, the torque on the front axle (c4') with the invention, and the torque on the rear axle (c5') with the invention. The lower section schematically illustrates second graph examples showing the time evolution of the vehicle's speed (c6'), the speed of the front wheels (c7') without the invention, the speed of the rear wheels (c8') without the invention, the speed of the front wheels (c9') with the invention, and the speed of the rear wheels (c10') with the invention. These second graph examples are under the conditions defined by the second graph examples.

[0028] - Figure 5 An example algorithm for implementing the control method according to the present invention is illustrated schematically. Detailed Implementation

[0029] The present invention is particularly intended to provide a land vehicle V, the land vehicle including a powertrain (or GMP) including at least a first prime mover MM1 and a second prime mover MM2 that provide torque to a first axle T1 and a second axle T2 respectively (driving) the wheels, wherein torque distribution can be controlled when instability is present.

[0030] In the following text, by way of non-limiting example, the land vehicle V is considered to be of the motorized type. The vehicle, for example, refers to an automobile, such as... Figure 1 As shown above. However, the present invention is not limited to this type of vehicle. In fact, the present invention relates to any type of land vehicle including a powertrain (or GMP), said powertrain particularly including at least a first prime mover and a second prime mover providing torque to a first axle and a second axle respectively (driving) the wheels. Therefore, the present invention also relates to, for example, utility vehicles, motorhomes, minibuses, long-distance buses, trucks, motorcycles, road construction machinery, construction site machinery, agricultural machinery, recreational machinery (snowmobiles, go-karts), tracked machinery, and manned adventure machinery.

[0031] Here, "prime mover" is understood as a machine that generates torque to move a vehicle based on energy stored in an energy storage component. Such a machine can therefore be thermal or non-thermal. A thermal prime mover is an engine (e.g., a reactor, turbojet engine, or chemical engine) that consumes fuel or chemicals. A non-thermal prime mover can be, for example, an electric motor, a hydraulic machine, a pneumatic (or compressed air) machine, or an inertial flywheel.

[0032] Additionally, in the following text, by way of non-limiting example, the powertrain (or GMP) is considered to be of the hybrid type. However, the GMP may be of the fully electric type.

[0033] exist Figure 1 The above schematically illustrates a vehicle V according to the invention, the vehicle including a traction chain (here with a hybrid GMP drive chain), a monitoring computer CS capable of monitoring (or managing) the operation of the drive chain, a braking system SF, and a trajectory control device DCT.

[0034] The drivetrain here specifically includes a first prime mover MM1, an engine shaft AM, a first coupling device DC1, a gear shifting device BV, a first drive shaft AT1, a second prime mover MM2, a second coupling device DC2, a second drive shaft AT2, an energy storage component BR, and an optional third prime mover MM3.

[0035] It is important to note that, for the implementation of this invention, the GMP of vehicle V may not include the third prime mover MM3.

[0036] Here, the first prime mover MM1 is considered to be a thermal engine. However, this first prime mover can be a non-thermal (optionally electric) prime mover.

[0037] Furthermore, it is assumed here that the second prime mover MM2 is non-thermal, more precisely, electric. However, this second prime mover can be a thermal prime mover or a non-thermal prime mover other than electric.

[0038] The first prime mover MM1 includes a crankshaft (not shown) fixedly connected to the engine shaft AM for driving the engine shaft (AM) to rotate. The first prime mover MM1 provides torque to the first axle T1 of the drive wheels via a first coupling device DC1, an optional third prime mover MM3, and a gear shifting device BV, under the instruction of a monitoring computer CS.

[0039] For example, the first axle T1 is located at the front of the vehicle V and is preferably connected to the first driveshaft AT1 via the first differential (here, the front differential) D1, as shown in the figure. However, in a variant, the first axle T1 may be an axle located at the rear of the vehicle V (labeled T2 in the figure).

[0040] For example, the first coupling device DC1 can be a clutch. However, the first coupling device can also involve a torque converter or a crabot.

[0041] The gear shifting device BV can be configured, for example, as a gearbox. This gear shifting device includes: a main shaft (or input shaft) AP for receiving torque; and a countershaft (or output shaft) for receiving the torque via the main shaft AP to transmit it to a first driveshaft AT1 to which it is connected, the first driveshaft being indirectly connected to the drive wheels (here, the front drive wheels) of the vehicle V via a first differential D1. However, in implementation variations, the gear shifting device BV may, for example, include at least one planetary gear train comprising one, two, or three synchronizers. Typically, any type of gearbox can be configured as the gear shifting device BV here.

[0042] The second prime mover MM2 is electric (this is not mandatory). When the second prime mover is connected to the second axle (T2) via the second coupling device DC2, the second prime mover is responsible for generating torque for the second axle T2, the drive wheel, based on the energy stored in the energy storage unit BR, under the instruction of the monitoring computer CS.

[0043] For example, the second axle T2 is located at the rear of the vehicle V, and is preferably connected to the second driveshaft AT2 via the second differential (here, the rear differential) D2, as shown in the figure. However, in the above variation, the second axle T2 may be located at the front of the vehicle V.

[0044] The second connecting device DC2 can be, for example, a claw connector. However, the second connecting device can also involve a clutch.

[0045] Considering the choices mentioned above, the energy storage component BR is configured here to store the electrical energy. Therefore, this energy storage component here relates to, for example, a low-voltage type (typically 220V, 400V, or 600V) rechargeable battery.

[0046] The optional third prime mover MM3 is non-thermal. For example, when the third prime mover is connected to the first axle (T1) via the gear shifting device BV, the third prime mover can be of an electric type. The third prime mover is responsible for generating torque for the first axle T1 driving the drive wheels based on the energy stored in the energy storage unit (BR) under the instruction of the monitoring computer CS.

[0047] It was also noted that, such as Figure 1 As shown in the above non-limiting illustration, the drivetrain here includes a starter or AC starter AD connected to the first prime mover MM1, which is responsible for actuating the first prime mover (MM1) to enable it to start. This actuation is carried out by electrical energy, which, for example and as shown in the non-limiting illustration, is stored in a service battery BS. The service battery (BS) may be, for example, of an ultra-low voltage type (e.g., 12V, 24V, or 48V). The service battery (BS) may also, for example, power an onboard network to which the electrical equipment of the vehicle V is connected. Note that the service battery BS may be connected to a rechargeable battery BR and a second prime mover MM2 via a DC / DC type converter CV, as shown in the non-limiting illustration, so that it can be recharged.

[0048] The operation of the first prime mover MM1, the second prime mover MM2 and the third prime mover MM3, the operation of the first coupling device DC1 and the second coupling device DC2, and the operation of the gear shifting device BV can be controlled by the monitoring computer CS.

[0049] The monitoring computer CS is specifically configured to control the torque distribution between the first axle T1 and the second axle T2.

[0050] The trajectory control device (DCT) is specifically configured to control the braking system (SF), particularly selectively controlling each wheel-associated sub-section of the braking system when instability of the vehicle (V) is detected. This detection is performed based on information measured (or estimated) by sensors (more precisely, sensors associated with the wheels for measuring the current rotational speed of the wheels, lateral acceleration sensors, sensors for providing the current speed of the vehicle, yaw sensors, and sensors associated with the steering wheel of the vehicle (V) for measuring the rotational angle of the steering wheel).

[0051] Additionally, the trajectory control device (DCT) is configured to, when the trajectory control device detects instability in the vehicle V, instruct the monitoring computer (CS) to maintain the current torque distribution in its original state and control the braking system (SF) until the instability disappears. Then, once the instability is observed to have disappeared, the trajectory control device (DCT) is configured to authorize the monitoring computer (CS) to perform modifications to the torque distribution (when modifications to the torque distribution are required).

[0052] Therefore, the trajectory control device DCT can temporarily "take over" torque distribution by acting on the braking system to eliminate instability of the vehicle V, which allows tangential engagement of the rotational speeds of one of the prime movers MM1 to MM3 to avoid impacts from the grounded wheels or violent recovery of grip. In fact, this allows the trajectory control device DCT to operate in real time, and detected instability is not modified by changes in torque distribution determined by the monitoring computer CS. Furthermore, when a wheel on one axle (T1 or T2) slips, there is no longer a risk of a significant increase in the rotational speed of the wheels on the other axles (T2 or T1). Indeed, as will be seen later, there is no longer a significant increase in the rotational speed of the wheels on the other axles.

[0053] Note that, Figure 1 In the non-limiting GMP example shown above, the torque distribution between the first axle T1 and the second axle T2 can be "frozen" (or maintained) in a fully electric mode (heat engine MM1 is off), rather than in a hybrid mode only.

[0054] It is also noted that when instability of vehicle V is detected in the absence of any modification to the current torque distribution, the trajectory control device DCT can be configured to command the monitoring computer CS to maintain the current torque distribution and control the braking system SF until the instability disappears, and then authorize the monitoring computer CS to perform a modification to the current torque distribution (when a modification to the current torque distribution is required).

[0055] exist Figure 3 The above schematically illustrates two examples of first graphs corresponding to the following scenario, in which the trajectory control device DCT detects instability in the vehicle V when there is initially no modification to the torque distribution.

[0056] lie in Figure 3 The graph in the upper part shows a first example of how the following items evolve over time:

[0057] -The constant torque (curve c1) required here by the driver of vehicle V.

[0058] - The torque (curve c2) on the first (front) axle T1 when this invention is not present.

[0059] - The torque (curve c3) on the second (rear) axle T2 when this invention is not present.

[0060] - The torque (curve c4) on the first (front) axle T1 when the present invention is present, and

[0061] - The torque (curve c5) on the second (rear) axle T2 when the present invention is present.

[0062] lie in Figure 3 The graph in the lower part shows a first example of how the following items evolve over time:

[0063] -Vehicle speed (curve c6),

[0064] -The speed of the front wheel (T1) (curve c7) when this invention is not present.

[0065] -The speed of the rear wheel (T2) (curve c8) when this invention is not present.

[0066] -The speed of the front wheel (T1) (curve c9) when the present invention is present, and

[0067] - The speed (c10) of the rear wheel (T2) when the present invention is present.

[0068] In the absence of this invention, at time t1, the trajectory control device DCT detects instability in vehicle V (a strong increase in the speed of the front wheel (T1) (curve c7) relative to the speed of vehicle V (curve c6)), and therefore begins to act on the braking system SF to eliminate the strong increase in the speed of the front wheel (T1) (curve c7). Simultaneously, the monitoring computer CS here forcibly implements a modification to the current torque distribution. The action of the trajectory control device DCT on the braking system SF very quickly brings the speed of the front wheel (T1) (curve c7) towards the speed of vehicle V (curve c6), but the modification to the torque distribution results in a very strong increase in the speed of the rear wheel (T2) (curve c8) relative to the speed of vehicle V (curve c6). The trajectory control device DCT may (after resolving the problem involving the first (front) axle T1) only respond to this increase after a certain delay, which makes the trajectory control device spend a lot of time.

[0069] When the present invention is present, at time t1, the trajectory control device DCT detects instability in vehicle V and therefore commands the monitoring computer CS to maintain the current torque distribution (constant curves c4 and c5 between t1 and t2) and act on the braking system SF to eliminate the strong increase in the speed of the front wheel (T1) (curve c9) relative to the speed of vehicle V (curve c6). At time t2, the trajectory control device DCT senses that the instability has disappeared and therefore authorizes the monitoring computer CS to perform a modification to the current torque distribution (when a modification to the current torque distribution is required). Here, exactly after time t2, the monitoring computer CS decides to perform a modification to the current torque distribution (a decrease in the torque (curve c4) on the first (front) axle T1 and an increase in the torque (curve c5) on the second (rear) axle T2), which results in the same increase in the speed of the front wheel (T1) (curve c9) and the speed of the rear wheel (T2) (curve c10), which is equal to the increase in the speed of vehicle V (curve c6), but without any new instability.

[0070] It is also noted that when instability of the vehicle V is detected after a current modification to the torque distribution, the trajectory control device DCT can be configured to determine whether the modification can continue. In the negative case (and therefore when the current modification cannot continue), the trajectory control device DCT commands the monitoring computer CS to maintain the current torque distribution as is. Conversely, in the positive case (and therefore when the current modification can continue), the trajectory control device DCT can determine a value characterizing a modification that can be made further based on the estimated change in grip between the wheels (the trajectory control device DCT estimates the grip and preventively limits the torque on the axle). Then, in the negative case as in the positive case, the trajectory control device DCT commands the monitoring computer CS to create a modification to the current torque distribution defined by the determined value, and controls the braking system SF until the instability disappears.

[0071] exist Figure 4 The above schematically illustrates two examples of second graphs corresponding to the following scenario: the trajectory control device DCT detects instability in the vehicle V caused (or amplified) by a current modification to the torque distribution determined by the monitoring computer CS.

[0072] lie in Figure 4 The graph in the upper part shows a second example of how the following items evolve over time:

[0073] - The constant torque (curve c1') required here by the driver of vehicle V.

[0074] -The torque (curve c2') on the first (front) axle T1 when this invention is not present.

[0075] - The torque (curve c3') on the second (rear) axle T2 when this invention is not present.

[0076] - The torque (curve c4') on the first (front) axle T1 when the present invention is present, and

[0077] - The torque (curve c5') on the second (rear) axle T2 when the present invention is present.

[0078] lie in Figure 4 The graph in the lower part shows a second example of how the following items evolve over time:

[0079] -Vehicle speed (curve c6')

[0080] -The speed of the front wheel (T1) (curve c7') when this invention is not present.

[0081] -The speed of the rear wheel (T2) (curve c8') when this invention is not present.

[0082] -The speed of the front wheel (T1) (curve c9') when the present invention is present, and

[0083] - The speed (c10') of the rear wheel (T2) when the present invention is present.

[0084] In the absence of this invention, at time t0, the monitoring computer CS begins to modify the current torque distribution. At time t1', when the modification of the torque distribution begins, the trajectory control device DCT detects instability in the vehicle V (a strong increase in the speed of the front wheel (T1) (curve c7') relative to the speed of the vehicle V (curve c6')) and therefore begins to act on the braking system SF to eliminate the strong increase in the speed of the front wheel (T1) (curve c7'). The action of the trajectory control device DCT on the braking system SF very quickly brings the speed of the front wheel (T1) (curve c7') towards the speed of the vehicle V (curve c6'), but the modification of the torque distribution causes a very strong increase in the speed of the rear wheel (T2) (curve c8') relative to the speed of the vehicle V (curve c6'). The trajectory control device DCT may (after resolving the problem involving the first (front) axle T1) only respond to this increase after a certain delay, which makes the trajectory control device spend a lot of time.

[0085] When the present invention is present, at time t1', when the modification of the torque distribution begins, the trajectory control device DCT detects instability in the vehicle V and thus determines whether the modification can continue. Here, it is assumed that continuation is impossible. Therefore, exactly after time t1', the trajectory control device DCT commands the monitoring computer CS to maintain the current torque distribution in its original state (curves c4' and c5' thus become constant between t1' and t2'). Simultaneously, the trajectory control device DCT acts on the braking system SF to eliminate the strong increase in the speed of the front wheel (T1) (curve c9') relative to the speed of the vehicle V (curve c6'). The action of the trajectory control device DCT on the braking system SF very quickly causes the speed of the front wheel (T1) (curve c9') to converge towards the speed of the vehicle V (curve c6'). At time t2', the trajectory control device DCT senses the disappearance of the instability and therefore authorizes the monitoring computer CS to execute (or continue) the modification of the torque distribution. Here, exactly after time t2', the monitoring computer CS decides to continue the modification of the torque distribution that it had already begun at time t0 (a decrease in torque on the first (front) axle T1 (curve c4') and an increase in torque on the second (rear) axle T2 (curve c5'). This results in the same increase in the speed of the front wheel (T1) (curve c9') and the speed of the rear wheel (T2) (curve c10'), which is equal to the increase in the speed of the vehicle V (curve c6'), but no new instability.

[0086] The trajectory control device (DCT) includes at least one computer (CA), which includes at least one processor (PR) (e.g., a digital signal processor (DSP)) and at least one memory (MD) performing the operations described above. The processor (PR) may include integrated (or printed) circuitry or multiple integrated (or printed) circuits connected via wired or wireless connections. "Integrated (or printed) circuitry" is understood to be any type of device capable of performing at least one electrical or electronic operation. The memory (MD) is randomly accessible to store instructions for implementing at least a portion of the control methods described further below by the processor (PR). The computer (CA) may therefore be implemented as a combination of electrical or electronic circuits or components (or "hardware") and software modules (or "software").

[0087] Note that, Figure 1 In the non-limiting example shown above, the trajectory control device DCT is external to the monitoring computer CS, but is connected to the monitoring computer (CS) directly or indirectly (e.g., via an internal communication network of an optional multiplexed type). However, in a variation of the implementation, the trajectory control device may be part of the monitoring computer CS.

[0088] It was also noted that, such as Figure 2 As shown in the above non-limiting description, the computer CA may also include (as a supplement to its own random access memory MD and processor PR) a large-capacity memory MM, which is specifically used to store the torque distribution, current values ​​of the vehicle V and the speeds of the front and rear wheels, yaw angle, lateral acceleration, and steering wheel angle determined by the monitoring computer CS, as well as intermediate data involved in all these calculations and processes. Additionally, the computer CA may also include an input interface IE for receiving at least the torque distribution, current values ​​of the vehicle V and the speeds of the front and rear wheels, yaw angle, lateral acceleration, and steering wheel angle determined by the monitoring computer CS, to optionally use this information in calculations or processes after it has been shaped and / or demodulated and / or amplified by means of a digital signal processor PR' in a manner known per se. Furthermore, the computer CA may also include an output interface IS, which is specifically used (at least for the braking system SF and the monitoring computer CS) to transmit messages and instructions from the computer.

[0089] The present invention can also be conceived as a control method implemented in a vehicle V. This control method can be implemented at least in part by the trajectory control device DCT described above.

[0090] The control method includes steps 10-50, wherein, upon detecting instability in the vehicle V, the trajectory control device DCT initiates by commanding the monitoring computer CS to maintain the current torque distribution in its original state and controlling the braking system SF until the instability disappears. Then, the trajectory control device DCT authorizes the monitoring computer CS to perform modifications to the torque distribution (when modifications to the torque distribution are required).

[0091] exist Figure 5 The above schematically illustrates an example of an algorithm for implementing the control method according to the present invention.

[0092] The algorithm includes sub-step 10, in which the trajectory control device DCT detects the instability of the vehicle V.

[0093] Then, in sub-step 20, the trajectory control device DCT commands the monitoring computer CS to maintain the current torque distribution in its original state.

[0094] Then, in sub-step 30, the trajectory control device DCT begins to control the braking system SF to eliminate the instability.

[0095] If the trajectory control device DCT observes that the instability has not disappeared in sub-step 40, the trajectory control device returns to execute sub-step 30. Conversely, when the trajectory control device DCT senses that the instability has disappeared in sub-step 40, the trajectory control device authorizes the monitoring computer CS to perform modifications to the torque distribution in sub-step 50 (when modifications to the torque distribution are required).

[0096] It is also noted that the present invention provides a computer program product (or computer program) comprising a set of instructions that, when executed by a processing unit of the electronic circuit (or hardware) type (e.g., a processor PR), implement the control method described above to control the torque distribution between the first axle T1 and the second axle T2 of the wheels of the vehicle V.

[0097] It is also noted that one or more sub-steps of the control method can be executed by different components. Thus, the control method can be implemented by multiple digital signal processors, random access memory, mass storage, input interfaces, and output interfaces.

Claims

1. A land vehicle (V), the land vehicle comprising at least a first prime mover (MM1) providing torque to a first axle (T1) of the wheels, a second prime mover (MM2) providing torque to a second axle (T2) of the wheels, a braking system (SF) acting on the wheels, a monitoring computer (CS) controlling the torque distribution between the first axle (T1) and the second axle (T2), and a trajectory control device (DCT) controlling the braking system (SF), characterized in that, When instability of the land vehicle (V) is detected, the trajectory control device (DCT) commands the monitoring computer (CS) to maintain the current torque distribution as is and controls the braking system (SF) until the instability disappears, and then authorizes the monitoring computer (CS) to perform modifications to the torque distribution.

2. The land vehicle according to claim 1, characterized in that, When instability of the land vehicle (V) is detected after the current modification of the torque distribution, the trajectory control device (DCT) determines whether the modification can continue. If not, the trajectory control device commands the monitoring computer (CS) to maintain the current torque distribution as is. If yes, the trajectory control device determines a value characterizing the modification that can be made further based on the estimated changes in grip between the wheels, and then commands the monitoring computer (CS) to create a modification of the current torque distribution defined by the determined value. In the same way as in the yes case, the trajectory control device controls the braking system (SF) until the instability disappears.

3. The land vehicle according to claim 1 or 2, characterized in that, When instability of the land vehicle (V) is detected without any modification to the current torque distribution, the trajectory control device (DCT) commands the monitoring computer (CS) to maintain the current torque distribution and controls the braking system (SF) until the instability disappears, and then authorizes the monitoring computer (CS) to perform a modification to the current torque distribution.

4. The land vehicle according to any one of claims 1 to 3, characterized in that, The first prime mover (MM1) is a heat engine.

5. The land vehicle according to claim 4, characterized in that, The land vehicle includes a third prime mover (MM3) that provides torque to the first axle (T1) of the wheels.

6. The land vehicle according to claim 5, characterized in that, The third prime mover (MM3) is an electric motor powered by a rechargeable battery (BR).

7. The land vehicle according to any one of claims 1 to 6, characterized in that, The second prime mover (MM2) is an electric motor powered by a rechargeable battery (BR).

8. A control method for a land vehicle (V), the land vehicle comprising at least a first prime mover (MM1) providing torque to a first axle (T1) of the wheels, a second prime mover (MM2) providing torque to a second axle (T2) of the wheels, a braking system (SF) acting on the wheels, a monitoring computer (CS) controlling the torque distribution between the first axle (T1) and the second axle (T2), and a trajectory control device (DCT) controlling the braking system (SF), characterized in that, The control method includes steps (10-50), wherein when instability of the land vehicle (V) is detected, the trajectory control device (DCT) commands the monitoring computer (CS) to maintain the current torque distribution in its original state and controls the braking system (SF) until the instability disappears, and then authorizes the monitoring computer (CS) to perform modifications to the torque distribution.

9. A computer program product comprising a set of instructions, said set of instructions being capable of implementing the control method of claim 8 when executed by a processing unit to control torque distribution between a first axle (T1) and a second axle (T2) of the wheels of a land vehicle (V), said land vehicle comprising at least a first prime mover (MM1) providing torque to the first axle (T1), a second prime mover (MM2) providing torque to the second axle (T2), a braking system (SF) acting on the wheels, a monitoring computer (CS) for controlling the torque distribution, and a trajectory control device (DCT) for controlling the braking system (SF).

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