Method and system for securing the takeoff of a vehicle equipped with a vehicle speed regulation system

Abstract

Title: Method and system for securing the takeoff of a vehicle equipped with a vehicle speed control system. This method for securing the takeoff of a vehicle equipped with a speed control system and an engine includes, following engine shutdown by the speed control system, the issuance of a takeoff confirmation request, the detection of a resumption of vehicle speed control by the driver instead of the speed control system, and securing the takeoff by limiting engine torque when an obstacle is detected and a resumption of speed control by the driver via acceleration is detected. No figure is provided for the abstract.

Description

Title of the invention: Method and system for securing the takeoff of a vehicle equipped with a vehicle speed regulation system

[0001] The invention relates to a method for safely preventing the takeoff of a motor vehicle, corresponding to restarting the engine and moving the vehicle after the engine has stopped under predefined conditions. The invention further relates to a system for safely preventing the vehicle from taking off. Finally, the invention relates to a vehicle equipped with such a safety system.

[0002] In the automotive industry, it is common practice to equip vehicles with a vehicle speed regulation system, known as ACC, short for "Adaptive Cruise Control." Such a system is capable of adapting the vehicle's speed according to its surroundings and traffic conditions, for example, depending on the vehicles present on the road.

[0003] In particular, such systems can be implemented to manage the speed of the ego vehicle during takeoff phases following an engine shutdown, corresponding to phases during which the vehicle transitions from a standstill, i.e., from zero speed, to a non-zero speed. Specifically, the speed control system can ensure automatic or semi-automatic stopping and takeoff of the ego vehicle, also known as ACC "Stop'n'GO", based on predefined conditions so as to allow for the automated restart of the ego vehicle following a stop.

[0004] As is known, takeoff can be subject to confirmation by the driver. Typically, such confirmation is implemented by pressing a button, for example located on the steering wheel, or by pressing the accelerator pedal. In the latter case, situations of misuse have been observed where the driver maintains pressure on the accelerator pedal instead of releasing it after confirmation and once the vehicle has begun its takeoff phase. This results in a situation known as "override" of the speed control system, in which the speed of the vehicle is suddenly controlled by the driver and no longer by the speed control system. The driver is then responsible for the vehicle's speed, which can lead them to approach an obstacle or vehicle in front of the vehicle dangerously, or even to collide with it.

[0005] The present invention falls within this context and aims to propose a method and a system for securing the ego vehicle during a takeoff situation, remedying the above disadvantages.

[0006] The invention relates to a method for securing the takeoff of a vehicle equipped with a speed control system and an engine, the method comprising, following the shutdown of the engine by the speed control system: - the detection, via a processing unit, of a vehicle stop implemented by the speed regulation system; - the issuing of a confirmation request, by the speed control system, for the execution of a restart of the vehicle's engine and a start of the vehicle's movement; - the detection of driver confirmation by pressing a vehicle accelerator pedal and the detection of a resumption of vehicle speed control by the driver instead of the speed regulation system, such resumption of control resulting from pressing a vehicle accelerator pedal according to at least one predefined condition in response to the issuance of a confirmation request; - the detection of at least one obstacle present in the environment outside the vehicle on a road traveled by the vehicle, particularly in front of the vehicle, when a resumption of speed control by the driver is implemented; - Securing the restart and movement of the vehicle by limiting the torque of the vehicle's engine when an obstacle is detected and a resumption of speed control by the driver by pressing on the accelerator pedal is detected.

[0007] In particular, at least one predefined condition for the driver to regain control of the speed is a duration of pressure on the accelerator pedal or a level of pressure on the accelerator pedal, the method comprising the detection of a duration of pressure or a level of pressure on the accelerator pedal by the processing unit and / or the speed control system, the resumption of speed control by the driver instead of the speed control system being implemented when a duration of pressure on the accelerator pedal is strictly greater than a predefined pressure duration threshold during confirmation or when a level of pressure on the accelerator pedal is strictly greater than a predefined pressure duration threshold during confirmation.

[0008] Optionally, the issuance of a confirmation request is conditional upon: - the detection of a vehicle engine stop duration, the issuance of a confirmation request being implemented when the stop duration is greater than or equal to a predefined stop duration threshold; and / or - the detection of at least one obstacle present in the environment outside the vehicle on the road traveled by the vehicle, particularly in front of the vehicle, the issuing of a confirmation request is implemented when at least one obstacle is detected.

[0009] According to one embodiment, the method further comprises the detection or determination of a distance separating the vehicle from the obstacle when an obstacle is detected, the limitation of the engine torque being determined as a function of said distance.

[0010] Additionally or alternatively, the method further comprises the detection or determination of a defined relative speed with respect to the obstacle when an obstacle is detected, the limitation of the motor torque being determined as a function of said relative speed.

[0011] Optionally, the method includes the acquisition of additional data relating to a context external to the vehicle, in particular selected from weather conditions, road surface condition and / or road slope, the limitation of the engine torque being determined according to the data relating to the context external to the vehicle.

[0012] According to an example of an embodiment, the method includes an interruption of the vehicle's torque limitation when at least one of the following is detected: a release of pressure on the accelerator pedal, a disappearance of the obstacle, exceeding a predefined speed threshold, or pressing the accelerator pedal to its maximum depressed position.

[0013] Optionally, the engine torque limitation of the vehicle is achieved by: - ​​determining a predicted limited torque value corresponding to a minimum value selected between a torque value defined according to the driver's level of pressure on the accelerator pedal and a limited torque value according to at least one parameter relating to the environment external to the vehicle and / or the obstacle; then - the selection of a final limited torque value corresponding to a maximum torque value selected from the calculated forecast limited torque value and a torque value envisaged by the speed regulation system as a function of at least one parameter relating to the obstacle.

[0014] The invention also relates to a system for securing the relaunch of a vehicle equipped with a speed regulation system and an engine, the system comprising hardware and / or software elements implementing the method according to the invention, the hardware elements comprising at least one data processing unit, a means of detecting an environment external to the vehicle and a control module capable of limiting engine torque.

[0015] The invention can also be extended to a motor vehicle comprising an engine, a vehicle speed regulation system and a vehicle restart safety system according to the invention.

[0016] The invention further extends to a computer program product comprising program code instructions stored on a computer-readable medium for implementing the steps of the security method according to the invention when said program is run on a computer. Alternatively, the invention relates to a computer program product downloadable from a communication network and / or stored on a computer-readable and / or computer-executable data medium comprising instructions which, when the program is executed by the computer, cause the computer to implement the security method according to the invention.

[0017] The invention finally extends to a data recording medium, readable by a computer, on which is recorded a computer program comprising program code instructions for implementing the security method according to the invention.

[0018] Other details, features and advantages will become clearer upon reading the detailed description given below, by way of example and not limitation, in relation to the various embodiments illustrated in the following figures:

[0019] Fig. 1 is a schematic view of an embodiment of a system for securing the takeoff of a vehicle equipped with a speed regulation system.

[0020] Fig. 2 is a general flowchart of an example of the execution of a method for securing a vehicle takeoff.

[0021] The [Fig.3] is a flowchart detailing alternative executions of the processes according to the invention.

[0022] Fig. 4 is a schematic representation of a vehicle takeoff situation.

[0023] Fig. 5 is a graph representing the evolution of a torque limitation as a function of the distance separating an ego vehicle from an obstacle.

[0024] Figure 1 schematically illustrates an embodiment of a motor vehicle 1 equipped with a powertrain, also referred to as an engine 2. The vehicle 1 may have a thermal, electric, or hybrid engine. The vehicle 1 may also be, for example, a passenger car, a commercial vehicle, a truck, or a bus. Optionally, the vehicle 1 may be a connected vehicle or an autonomous vehicle.

[0025] Throughout the description below, the vehicle 1 comprising the means for implementing the invention may also be referred to as the "ego" vehicle in order to to distinguish it from other surrounding vehicles, the term "ego" does not in itself confer any technical limitation on vehicle 1 automobile. We will also identify "secondary vehicles" corresponding to vehicles of any type distinct from vehicle 1 ego circulating in the road infrastructure, for example cars, bicycles, motorcycles, and others.

[0026] Vehicle 1 is equipped with at least one vehicle speed control system 3, also referred to as "adaptive cruise control" or "ACC," capable of regulating the driving speed of vehicle 1 according to traffic conditions in the road infrastructure. "Speed" refers in particular to the longitudinal speed of the vehicle.

[0027] Optionally, the speed control system 3 is associated with or included in a driving assistance system, or AD AS, from the English "Advanced Driving Assist System" allowing the driving conditions of the vehicle 1 to be adapted, for example its speed, according to the context in which the vehicle 1 is driving.

[0028] In a known manner, the speed control system 3 is particularly capable of managing the speed of vehicle 1 during a stopping phase of vehicle ego 1, as further detailed below, including stopping the engine 2 of vehicle ego 1 and immobilizing vehicle ego 1.

[0029] In the context of the invention, the speed control system 3 is particularly well-suited to managing the speed of vehicle 1 during a "take-off" phase, including the restart of engine 2 and the re-engagement of vehicle 1 following a stop, particularly following a stop initiated by the speed control system 3, also referred to as a "re-take-off" phase. The speed control system 3 of vehicle 1 is thus configured to allow vehicle 1 to stop and / or to accelerate from a standstill to a non-zero speed automatically or semi-automatically.

[0030] In the case of prior art speed control systems, such systems may allow the vehicle's engine to restart automatically after it has stopped, provided no obstacle is detected in front of the vehicle. Also, as is known, takeoff may require confirmation by the driver by pressing the accelerator pedal. In such prior art systems, if the accelerator pedal is pressed for an extended period, speed control may be transferred to the driver instead of the speed control system through a process known as "speed control override." The driver is then suddenly responsible for the vehicle's speed, which may cause it to approach an obstacle in front of the vehicle dangerously.

[0031] In order to prevent such situations, the vehicle 1 according to the invention further comprises a system for securing a takeoff of the vehicle 1, which includes Hardware and / or software components capable of implementing, or designed to implement, a method for securing a takeoff of vehicle 1 described below. These hardware components include at least one data processing unit, at least one means of detecting an environment external to vehicle 1, and a control module capable of controlling engine 2, in particular capable of limiting the torque of engine 2.

[0032] The processing unit 10 is capable of receiving data from at least one sensing means 11, relating to the environment external to the vehicle 1. It comprises at least one computer with hardware and software resources, more specifically at least one processor or microprocessor, capable of processing said data and executing instructions for the implementation of a computer program. The processing unit 10 includes memory elements or is capable of cooperating with memory elements of the vehicle 1.

[0033] For example, the at least one detection means 11 is an optical detection means 11, such as a camera, a scanning laser or a "LIDAR", from the English "Light Detection And Ranging", capable of providing information relating to the environment outside the vehicle 1 to the processing unit 10. In particular, the at least one detection means 11 is equipped at the front of the vehicle 1 or on a roof of the vehicle 1 in order to acquire data relating to a portion of the external environment located upstream of the vehicle 1. In particular, the at least one detection means 11 is capable of detecting an obstacle Wx, in particular located in front of the vehicle 1. Here, "obstacle" means a road user present in the road infrastructure in the path of the vehicle 1, in particular in front of the vehicle 1, such as a pedestrian, a bicycle, a motorcycle, a scooter, a car or any other motorized vehicle 1.

[0034] For example, the obstacle Wx can be: - a primary target followed or used as a reference by the speed regulation system 3 and / or the safety system 4 at a time t; - an intermediate target, corresponding to a road user such as a pedestrian, a bicycle, a motorcycle, a scooter, a car or any other motorized vehicle 1 intervening between the vehicle 1 ego and a primary target at a time t, said intermediate target being liable to be reclassified as a primary target at a time t+x.

[0035] Optionally, the vehicle 1 and / or the safety system 4 further comprises at least one sensing element 12 capable of determining and providing data relating to the depressment of an accelerator pedal 13 equipping the vehicle 1, such as whether or not the pedal is depressed, the degree of depressment, or the duration of depressment. Such a sensing element 12 may be a specific sensor and / or a part of the speed regulation system 3 and is capable of transmitting data to the processing unit 10.

[0036] The control module 14 is configured to receive instructions from the processing unit 10 and to control the engine 2 of the vehicle 1 in particular in order to modulate, particularly limit, its torque.

[0037] Optionally, the vehicle 1 further comprises a location means 5, particularly capable of transmitting information to the processing unit 10 of the security system 4. The location means 5 makes it possible to determine the position of the vehicle 1 within the road infrastructure, particularly by satellite. It incorporates, for example, a vehicle 1 location system and / or a map of the road infrastructure. In particular, the location of the vehicle 1 may be provided by a GPS-type system, the acronym for "Global Positioning System". The location of the vehicle 1 makes it possible to extract from a mapping database information concerning the road infrastructure, the condition, the topology, and / or the geography of roads around the position of the vehicle 1.Optionally, the location of vehicle 1 allows the extraction of data relating to the environment outside the vehicle, for example relating to weather conditions or the condition of a road or pavement.

[0038] An embodiment of the method for securing 100 during the takeoff of vehicle 1 is described below. Such a method can also be considered a method for operating a vehicle 1 according to the invention.

[0039] The method of securing 100 a takeoff of vehicle 1 includes in the first stage, the detection E01, by means of the processing unit 10, of a stop of vehicle 1 implemented by the speed control system 3. In other words, the security system 4 is capable of detecting the stopping of vehicle 1 by the speed control system 3 following the execution of such a stop.

[0040] Here, "stop" means that the operation of the engine 2 of the vehicle 1 ego is interrupted and that the vehicle 1 ego is static, that is to say, it effectively has zero speed.

[0041] Indeed, in a conventional manner, the safety system 4 is capable of bringing vehicle 1 ego to a stop under specific predefined conditions, for example, depending on an obstacle Wx, or a tracked primary target, present in the environment external to vehicle 1 ego, particularly in front of vehicle 1 ego. Such conditions are, by way of non-limiting example, related to the stopping of obstacle Wx, its speed, its relative speed, defined with respect to vehicle 1 ego, and / or a distance relative to vehicle 1 ego.

[0042] When the safety system 4 implements such a stop, it can, for example, adapt the speed according to the conditions relating to the aforementioned obstacle Wx up to that vehicle 1 is at rest. Optionally, motor 2, for example an electronic unit equipping vehicle 1 associated with motor 2, also referred to as CAN bus abbreviated from the English "Controller Area Network", is able to detect when the vehicle is actually stationary and / or that the torque of motor 2 is zero.

[0043] In the context of the invention, according to embodiment examples, the safety system 4 is configured to receive data relating to a stop of the vehicle 1 implemented by the speed control system 3 directly through said speed control system 3, for example by detection of a stop command issued by said system, and / or through an electronic unit equipping the vehicle 1, for example associated with the engine 2 as indicated above.

[0044] Alternatively or additionally, the safety system 4 detects a stop of vehicle 1 by detecting predefined conditions for stopping vehicle 1 by the speed control system 3, for example by detecting data relating to a deceleration of vehicle 1 until it reaches zero speed or a speed below a predefined threshold triggering the stopping of vehicle 1 by the speed control system 3. The detection E01 of the implementation of such conditions can then be carried out by means of a sensor suitable for measuring the speed or deceleration of vehicle 1 or by means of the speed control system 3.

[0045] The safety method 100 according to the invention further comprises issuing a confirmation request E03 for the execution of a restart of the engine 2 of vehicle 1 and the starting of vehicle 1, in other words, a confirmation of the execution of a takeoff, or re-takeoff, of vehicle 1. In particular, such a confirmation request E03 for the vehicle's takeoff originates from the speed control system 3.

[0046] In particular, the issuance of a confirmation request E03 includes a substep of issuance E031 of a confirmation request message to the driver, such as a visual message emitted via a Human-Machine Interface or a screen fitted on the vehicle 1 and / or an audible message emitted via a loudspeaker included in the vehicle 1.

[0047] As is known, confirmation of the takeoff of vehicle 1 can be initiated by pressing the vehicle's accelerator pedal 13. According to an alternative not relevant to the execution of the method according to the invention, such confirmation can be performed via a button on vehicle 1. The confirmation request message sent to the driver then indicates the action to be taken to confirm the intention to initiate a takeoff of vehicle 1.

[0048] The method according to the invention further comprises the detection E04 of the driver's confirmation. In other words, in this case, the method comprises the detection E4 of the confirmation implemented by pressing the accelerator pedal 13. The detection of the press on the accelerator pedal 13 is carried out via the vehicle's speed control system 3 by known means, which transmits to the processing unit 10 of the safety system 4 according to the invention that it has received such confirmation of takeoff by pressing the accelerator pedal 13. According to an alternative embodiment, the safety system 4 comprises a sensor, such as a force or strain sensor or the detection element 12 described above, capable of detecting at least one press on the accelerator pedal 13 and / or a level of pressure on said accelerator pedal 13.

[0049] Optionally, as illustrated in [Fig. 3], the issuance of the confirmation request E03 can be conditional. For example, the issuance of the confirmation request E03 is conditional upon the detection of an obstacle Wx and / or a stopping time of vehicle 1 ego.

[0050] When such an emission E03 is conditioned on the detection of an obstacle Wx, said emission step E03 includes a detection substep E020 of an obstacle Wx present in the environment external to vehicle 1, in particular located in front of vehicle 1, i.e., on the trajectory of vehicle 1 as it moves forward. For example, the obstacle Wx considered corresponds to a primary target tracked or used as a reference by the speed control system 3 at a time when the stopping of vehicle 1 is implemented by the speed control system 3 as described above.Alternatively, the obstacle Wx is an intermediate target interposed between the vehicle 1 ego and the primary target tracked or used between the moment when the vehicle 1 ego is brought to a stop and the moment when the method according to the invention, in particular the confirmation step E03, is executed, said intermediate target being capable of being reclassified as a primary target by the speed control system 3 for the purpose of restarting the vehicle 1. As indicated above, "obstacle Wx" means a road user present in the road infrastructure in the path of the vehicle 1, in particular in front of the vehicle 1, such as a pedestrian, a bicycle, a motorcycle, a scooter, a car or any other motorized vehicle 1.

[0051] The detection E020 of the obstacle Wx is carried out directly through at least one detection means 11 as described above, in particular an optical detection means 11 such as a camera, a scanning laser or a "LIDAR", and / or through the speed control system 3 comprising such a detection means 11.

[0052] Such detection E020 of the obstacle Wx can be carried out in real time following the detection E01 of a stop or at predefined regular time intervals, the issuance of the confirmation request being carried out when an obstacle Wx is detected.

[0053] Alternatively, the issuance of the confirmation request E03 is conditional upon the vehicle 1 ego's stopping time. The method 100 then comprises the detection E020' of a vehicle 1 ego's stopping time, in particular the engine 2 stopping time, via at least one sensor or the processing unit 10 as described above, the issuance E03 of a confirmation request being implemented when the vehicle 1 ego's stopping time is greater than or equal to a predefined stopping time threshold. For example, the stopping time threshold is defined by the speed control system 3, as described below.

[0054] The method according to the invention is particularly aimed at ensuring the safety of the takeoff of the vehicle 1 ego in a situation where the driver takes back control of the speed of the vehicle 1 ego instead of the speed regulation system 3, that is to say in a situation known as "over ride" of the speed control, automatic or semi-automatic, implemented by the speed regulation system 3.

[0055] For example, in a known manner, the vehicle 1 ego and / or the speed control system 3 is configured so that speed control is ensured by the driver instead of the speed control system 3 in the event of prolonged pressure on the accelerator pedal during the implementation of the confirmation executed by the driver in response to the request for confirmation of a takeoff.

[0056] In order to detect such an "over ride" situation, the method according to the invention includes the detection of a resumption of control E05 of the speed of the vehicle 1 ego by the driver instead of the speed regulation system 3, such a resumption of control resulting from a press on the accelerator pedal carried out according to at least one predefined condition.

[0057] In a particular example, at least one predefined condition for the driver to regain speed control is a duration of press on the accelerator pedal 13. The method, in particular the step of detecting driver resumption of control E05, then includes detecting a press duration for a press on the accelerator pedal 13 in response to a takeoff confirmation request. The control system 3 and / or the vehicle 1 is then configured to implement driver resumption of speed control instead of the speed control system when a press duration on the accelerator pedal 13 is strictly greater than a predefined press duration threshold.

[0058] Alternatively, at least one predefined condition for the driver to regain control of the speed is a certain level of pressure on the accelerator pedal 13, in other words, a degree of pedal deflection. It is understood that the description then applies mutatis mutandis to such an alternative.

[0059] Such detection E05 can be performed indirectly by detecting a command issued by the speed control system 3 indicating that longitudinal speed control is being transferred to the driver following detection, by the speed control system 3, of an exceedance of the pressure duration threshold as indicated above. Alternatively or additionally, such detection is performed directly by the safety system 4 by measuring the pressure duration on the accelerator pedal 13 via the detection device 12. The processing unit 10 then receives information relating to the resumption of control by the driver from the speed control system 3 and / or the detection device 12.

[0060] When the driver resumes speed control, the method performs a detection step E06 of an obstacle Wx present in the environment outside the vehicle on the road traveled by the vehicle, specifically in front of the vehicle. Similar to what was described previously in the context of the execution of the confirmation request issuance step E03, the obstacle Wx considered corresponds to a primary target tracked or used as a reference by the speed control system 3 at an execution time t following the detection of the driver's resumption of speed control. Alternatively, the obstacle Wx is an intermediate target interposed between the vehicle 1 and the primary target tracked or used following the detection of the driver's resumption of longitudinal speed control.

[0061] The detection E06 of the obstacle Wx following the detection of the resumption of control of the speed regulation by the driver is carried out directly via at least one detection means 11 similarly to that described above, in particular an optical detection means 11 such as a camera, a scanning laser or a "LIDAR", and / or via the speed regulation system 3 comprising such a detection means 11. Such detection E06 of the obstacle Wx can be carried out in real time or at predefined regular time intervals.

[0062] The processing unit 10 is then configured to implement the E07 safety feature for the takeoff of vehicle 1 ego, i.e., the restart and movement of vehicle 1 ego, by limiting, in particular temporarily, the engine torque of the vehicle when a situation where the driver regains control by pressing the accelerator pedal is detected and an obstacle is detected E06 in the environment external to vehicle 1 ego, in particular in front of it. Such a principle makes it possible to ensure the safety of the passengers of vehicle 1 when an obstacle Wx is present on the trajectory of vehicle 1 ego envisaged during the takeoff of vehicle 1 ego.

[0063] In particular, the securing E07 of vehicle 1 includes a substep E071 of determining, by the processing unit 10, the limitation of the torque of the engine 2 of vehicle 1 to be applied, then a substep of applying E072 the torque value determined by the control module 14, the processing unit transmitting the torque instruction to be applied to said module and the latter applying it to the engine 2.

[0064] Optionally, the torque limitation of the engine 2 of vehicle 1 is determined by the processing unit 10 as a function of a distance dx separating vehicle 1 from the obstacle Wx. In such a case, the detection E06 of the obstacle Wx by means of the detection means 11 as described above further includes the detection or determination of the distance dx separating vehicle 1 from the obstacle Wx. This distance dx is then transmitted to the processing unit 10 of the safety system 4. Thus, the smaller the distance dx separating vehicle 1 from the obstacle Wx, the greater the torque limitation of engine 2, and vice versa.

[0065] Alternatively or additionally, the torque limitation of the engine 2 of vehicle 1 is determined based on the relative speed of vehicle 1 with respect to the obstacle Wx. In such a case, the detection E06 of the obstacle Wx by means of the detection means 11 further includes the detection or determination of the relative speed of vehicle 1 with respect to the obstacle Wx. This relative speed is then transmitted to the processing unit 10 of the safety system 4. Thus, the lower the relative speed of vehicle 1 with respect to the obstacle Wx, the greater the torque limitation of engine 2, and vice versa.

[0066] Optionally, the torque limitation of engine 2 can be adapted to take into account external conditions affecting vehicle 1 that may impact its braking distance, such as weather conditions, road surface condition, and / or road gradient. The method also optionally includes a step for acquiring additional data E070 relating to the external context of vehicle 1, specifically selected from weather conditions, road surface condition, and / or road gradient. Such data acquisition is, for example, implemented simultaneously following the detection of a driver regaining control of the vehicle's speed. The torque limitation of engine 2 is then determined, additionally or alternatively, based on the data relating to the external context of vehicle 1.For example, on slippery roads, the torque limitation of engine 2 is greater than on normal roads, particularly dry or clear ones.

[0067] For example, the torque limitation of the engine 2 of vehicle 1 is obtained by determining a predictive limited torque value C_lim_prev corresponding to a minimum torque value selected between a torque value defined according to the driver's pressure level C_com_cond on the accelerator pedal 13 and at least one limited torque value C_tab defined according to at least one parameter relating to the environment external to the vehicle and / or the obstacle Wx. For example, the limited torque value C_tab is extracted from a predefined table of values ​​setting limited torque values ​​C_tab to be applied according to at least one parameter. In particular, at least one parameter is selected from those mentioned above, namely the distance separating vehicle 1 ego from the obstacle Wx, the relative speed defined with respect to said obstacle and / or at least one of the external conditions indicated above.

[0068] C_lim_prev = min(C_com_cond; C_tab)

[0069] Where

[0070] C_lim_prev is the predicted limited torque value, corresponding to the torque envisaged by the safety system 4 according to the invention.

[0071] C_com_cond is the torque value that would be applied based on the driver's level of pressure on the accelerator pedal 13.

[0072] C_tab is the pair value that would be applied by the security system, for example, on the basis of at least one table or graph associating pair values ​​with at least one parameter.

[0073] Thus, the minimum torque command is selected between a torque value recommended by the safety system 4 and a torque value corresponding to the pressure applied to the accelerator pedal 13, so that, if the pressure applied results in excessive torque, likely to cause a dangerous lift-off or even a collision, such a torque value is not selected. Figure 5 illustrates an example of how the torque value applied, based on the driver's pressure level C_com_cond on the accelerator pedal 13, changes as a function of the distance dx separating the vehicle 1 ego from the obstacle Wx, with curve G_cond, and an example of how the predefined torque value C_tab recommended by the safety system 4 changes as a function of at least one parameter, in this case distance, illustrated by curve G_tab.

[0074] It should be noted that the method according to the invention can be configured to take into account several distinct parameters from those mentioned above. For example, the predicted limited torque value C_lim_prev is the minimum value selected between the torque value defined according to the driver's pressure level C_com_cond on the accelerator pedal 13 and a plurality of limited torque values ​​C_tab_x, corresponding each to a suggested pair as a function of a parameter considered among the plurality of parameters mentioned above, said values ​​being extracted from different tables or graphs of predefined values ​​fixing values ​​of limited pair C_tab_x as a function of one of the parameters considered.

[0075] Then, the determination of the torque limitation of the engine 2 of the vehicle 1 is obtained by selecting a final limited torque value C_lim_fin, corresponding to the value of the torque limitation to be applied and being a maximum torque value selected from the previously determined forecast limited torque value C_lim_prev, as indicated above, and a torque value envisaged C_acc by the speed control system 3 as a function of at least one parameter relating to the obstacle Wx.

[0076] 2) C_lim_fin = max (C_lim_prev; C_acc)

[0077] Where

[0078] C_lim_fin is the final limited torque value, corresponding to the final torque selected by the safety system according to the invention.

[0079] C_lim_prev is the value of the previously defined forecast limited torque.

[0080] C_acc is the torque value envisaged by the speed control system 3 based on the context external to the vehicle.

[0081] Optionally, the method is configured to implement an interruption of the temporary torque limitation of the vehicle 1 when at least one of the following is detected: release of pressure on the accelerator pedal 13, disappearance of the obstacle Wx, exceeding a speed threshold, or depressing the accelerator pedal 13 to its maximum position. Release of pressure on the accelerator pedal 13 or its maximum position is detected by means of a sensor, for example, a force or strain sensor. The disappearance of the obstacle Wx is detected by means of the optical detection means 11.

[0082] Thus, different takeoff situations of vehicle 1 can be implemented during the operation of vehicle 1 following a stop implemented by the speed regulation system 3.

[0083] When, following a stop of vehicle 1 by the speed control system 3, no obstacle Wx is detected, the speed control system 3 is classically able to implement the restart of the engine 2 and the starting of the vehicle 1 ego.

[0084] For example, when an obstacle Wx, in particular a tracked primary target, is detected for a prolonged period, that is to say, in particular for a period exceeding a maximum stopping time threshold D_stop_max, the stopping of vehicle 1 is maintained. Additionally, the various electronic units equipping vehicle 1 can be switched off for a prolonged stop.

[0085] In the event that, following a stop, an obstacle Wx is detected, vehicle 1 can issue a takeoff confirmation request as described above, i.e. a request to confirm the restart of engine 2 and the movement of vehicle 1 ego despite the presence of the obstacle Wx in the environment outside vehicle 1 ego, in particular in front of vehicle 1 ego.

[0086] As indicated above, optionally, the safety system 4 is configured to detect when the engine 2 of vehicle 1 has been idled for a certain period, with confirmation of restarting and moving the engine being implemented, for example, when the idle time is greater than or equal to at least one predefined idle time threshold. For example, at least one idle time threshold is defined by the speed control system 3 of vehicle 1, such that the confirmation request is communicated to the driver for a defined period, for example, either continuously or at regular time intervals.

[0087] According to a particular example, a plurality of stopping time thresholds are set so as to define a defined period during which the confirmation request is communicated to the driver, either continuously or at regular time intervals. For example, but not limited to, a first stopping time threshold is set at 30 seconds and a second stopping time threshold is set at 180 seconds so as to define a period of 30 to 180 seconds following the detection E01 of the engine 2 stopping during which the confirmation request can be made. Optionally, below the first stopping time threshold, the control system 3 is, for example, configured to initiate the takeoff of vehicle 1 without a confirmation request in the absence of an obstacle Wx, while above the second stopping time threshold, the speed control system 3 keeps vehicle 1 stopped.

[0088] When the driver does not make a confirmation or makes a confirmation via the button, similarly to what is done in the prior art, the speed control system 3 is in charge of the vehicle taking off and can maintain the vehicle 1 stopped or initiate its take-off depending on the evolution of the external environment in a conventional way.

[0089] The same applies when a confirmation is made by pressing the pedal in circumstances which do not trigger a resumption of control of the vehicle's speed by the driver instead of the speed control system 3. The speed control system 3 then remains in charge of the vehicle's takeoff and can maintain the vehicle 1 stopped or initiate its takeoff depending on the evolution of the external environment in a conventional manner.

[0090] When the driver makes a confirmation by pressing the accelerator pedal 13 in such a way that the driver implements at least one of the predefined conditions likely to trigger a situation of resumption of control of the vehicle speed by the driver instead of the speed regulation system 3, known as "over ride", and no obstacle is detected during the detection step E06 of an obstacle Wx, the takeoff of the vehicle 1 ego is implemented by the driver, who controls the speed of the vehicle 1 ego, without limitation of the torque of the engine 2. In other words, there is no particular securing of the vehicle and a mode known as "unsecured resumption of control" or "unsecured over ride" is implemented.

[0091] Conversely, when the driver confirms the action by pressing the accelerator pedal 13 in a manner that triggers the driver to take over control of the vehicle's speed instead of the speed control system 3, and an obstacle Wx is detected in the environment outside the vehicle 1 ego, particularly in front of the vehicle 1 ego, during the obstacle detection step E06, the driver initiates the takeoff of the vehicle 1 ego, controlling its speed, with the application of a torque limitation E07 to the engine 2 as described previously. In other words, a takeoff safety measure is implemented by limiting the torque, and a so-called "safe takeover" or "safe override" mode is activated to prevent the vehicle from getting too close to the detected obstacle Wx, or even colliding with it.

[0092] Such a limitation can then be interrupted by the implementation of at least one of the interruption conditions described above, such as releasing pressure on the accelerator pedal 13, the disappearance of the obstacle Wx, exceeding a speed threshold, or pressing the accelerator pedal 13 to its maximum depressed position. The operation of the speed control system 3 then returns to a conventional operating mode, without applying any limitation to the torque of the engine 2.

[0093] The invention thus proposes a method for securing the takeoff of a vehicle equipped with a speed control system, ensuring safe vehicle movement when an obstacle likely to impede the vehicle's proper restart is detected in a situation where the driver, instead of the speed control system, takes over control of the vehicle's speed. Furthermore, the proposed solution is low-cost and easily implemented on existing vehicles.

[0094] The present invention is not limited, however, to the means and configurations described and illustrated herein, and also extends to any equivalent means or configuration and to any technically feasible combination of such means in the to the extent that they ultimately fulfill the functionalities described and illustrated in this document.

Claims

Demands

1. Method for securing (100) a takeoff of a vehicle (1) equipped with a speed control system (3) and an engine (2), the method comprising, following the stopping of the engine (2) by the speed control system (3): - the detection (E01), via a processing unit (10), of a stop of the vehicle (1) implemented by the speed control system (3); - the emission (E03) of a request for confirmation, by the speed control system (3), of the execution of a restart of the engine (2) of the vehicle (1) and a movement of the vehicle (1);- the detection (E04) of driver confirmation by pressing an accelerator pedal (13) of the vehicle (1) and the detection (E05) of a resumption of vehicle speed control (1) by the driver instead of the speed control system (3), such resumption of control resulting from pressing an accelerator pedal (13) of the vehicle according to at least one predefined condition in response to the issuance of a confirmation request; - the detection (E06) of at least one obstacle (Wx) present in the environment external to the vehicle (1) on a road traveled by the vehicle (1), in particular in front of the vehicle (1), when a resumption of speed control by the driver is implemented;- the securing (E07) of the restart and movement of the vehicle (1) by limiting the torque of the engine (2) of the vehicle (1) when an obstacle (Wx) is detected and a resumption of speed control by the driver by pressing on the accelerator pedal (13) is detected.;

2. A safety method (100) according to the preceding claim, wherein at least one predefined condition for the driver to regain speed control is a duration of pressure on the accelerator pedal (13) or a level of pressure on the accelerator pedal (13), the method comprising the detection of a duration of pressure or a level of pressure on the accelerator pedal (13) by the processing unit (10) and / or the speed control system (3), the driver regaining speed control instead of the speed control system (3) being implemented when a duration the pressure on the accelerator pedal (13) is strictly greater than a predefined pressure duration threshold during confirmation or when a level of pressure on the accelerator pedal (13) is strictly greater than a predefined pressure duration threshold during confirmation.

3. A security method (100) according to any one of the preceding claims, wherein the issuance of a confirmation request is conditioned by: - ​​the detection of a stop time of the engine (2) of the vehicle (1), the issuance of a confirmation request (E03) being implemented when the stop time is greater than or equal to a predefined stop time threshold; and / or - the detection of at least one obstacle (Wx) present in the environment outside the vehicle (1) on the road traveled by the vehicle (1), in particular in front of the vehicle (1), the issuance of a confirmation request (E03) being implemented when at least one obstacle (Wx) is detected.

4. A securing method (100) according to any one of the preceding claims, further comprising the detection or determination of a distance (dx) separating the vehicle (1) from the obstacle (Wx) when an obstacle (Wx) is detected, the limitation of the torque of the engine (2) being determined as a function of said distance (dx).

5. A securing method (100) according to any one of the preceding claims, further comprising the detection or determination of a defined relative speed with respect to the obstacle (Wx) when an obstacle (Wx) is detected, the limitation of the torque of the motor (2) being determined as a function of said relative speed.

6. A safety method (100) according to any one of the preceding claims, further comprising the acquisition (E70) of additional data relating to a context external to the vehicle (1), in particular selected from weather conditions, road surface condition and / or road slope, the limitation of the engine torque (2) being determined according to the data relating to the context external to the vehicle (1).

7. A safety method (100) according to any one of the preceding claims, further comprising an interruption of the vehicle torque limitation (1) when at least one of a release of pressure on the accelerator pedal (13) is detected, disappearance of the obstacle (Wx), exceeding a predefined speed threshold or pressing the accelerator pedal (13) to its maximum depressed position.

8. A safety method (100) according to any one of the preceding claims, wherein the limitation of the torque of the engine (2) of the vehicle (1) is obtained by: - ​​determining a predictive limited torque value (C_lim_prev) corresponding to a minimum value selected between a torque value defined according to a level of driver pressure (C_com_cond) on the accelerator pedal (13) and a limited torque value (C_tab) according to at least one parameter relating to the environment external to the vehicle (1) and / or the obstacle (Wx); then - selecting a final limited torque value (C_lim_fin) corresponding to a maximum torque value selected from the calculated predictive limited torque value (C_lim_prev) and a torque value envisaged (C_acc) by the speed control system (3) according to at least one parameter relating to the obstacle (Wx).

9. A system for securing the relaunch of a vehicle (1) equipped with a speed regulation system (3) and an engine (2), the system comprising hardware and / or software elements implementing the method according to one of the preceding claims, the hardware elements comprising at least one data processing unit (10), a means for detecting an environment external to the vehicle (1) and a control module capable of limiting a torque of the engine (2).

10. Motor vehicle (1) comprising an engine (2), a speed control system (3) of the vehicle (1) and a vehicle (1) restart safety system (4) according to the preceding claim.

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