Method for managing the speed of a motor vehicle traveling on a traffic lane

Abstract

A method for managing the speed of a motor vehicle traveling in a traffic lane, said method being implemented by a processor, comprises the steps of: detecting (301) a first and a second vehicle preceding the motor vehicle in the traffic lane; determining (303) an instantaneous speed of the motor vehicle such that it maintains a first predetermined safety distance from the first vehicle and a second predetermined safety distance from the second vehicle; and the speed determination includes substeps of determining (307) the acceleration associated with maintaining the safety distances from each of the vehicles and selecting (309) the smallest acceleration. A system for managing technical data for the use of the functions of a motor vehicle and a motor vehicle comprising the system are also described. Figure to be published with the abbreviation: Fig 3

Description

Title of the invention: Method for managing the speed of a motor vehicle traveling on a traffic lane. Technical field

[0001] The present invention relates to a method for managing the speed of a motor vehicle traveling on a traffic lane, a device for managing the speed of a motor vehicle, a motor vehicle comprising such a device and a computer program product. State of the art

[0002] The term "vehicle" means any type of vehicle such as a motor vehicle, moped, motorcycle, warehouse robot, etc. "Autonomous driving" of a "vehicle" means any process capable of assisting the driving of the vehicle; the "vehicle" is then also called an "autonomous vehicle." The process may thus consist of partially or fully controlling the vehicle or providing any type of assistance to a person driving the vehicle. The process thus covers all autonomous driving, from level 0 to level 5 in the OICA (International Organization of Motor Vehicle Manufacturers) scale.

[0003] Methods capable of assisting the driving of the vehicle are also called AD AS (from the English acronym "Advanced Driver Assistance Systems"), AD AS systems or driver assistance systems.

[0004] Among driver assistance systems, adaptive cruise control is increasingly being implemented in vehicles. This function maintains a set speed while taking into account the vehicles ahead, and therefore slows down to maintain a safe distance if the vehicle ahead is traveling at a speed lower than the set speed.

[0005] This function is well implemented and safe, but it has been observed that some users complain of excessively rapid and therefore uncomfortable acceleration or deceleration. Indeed, when another vehicle merges into the lane in front of the vehicle without maintaining a safe distance, the vehicle will slow down, or even brake, to quickly regain that distance. Similarly, when the vehicle ahead leaves the lane, the vehicle will accelerate to regain the set speed. However, if it detects a second vehicle ahead of it in the lane at that moment, it may be forced to decelerate rapidly, even though it had begun to accelerate, in order to maintain the safe distance.

[0006] There is therefore a real need for a method and a system for managing the speed of a motor vehicle which resolves all or part of the aforementioned disadvantages. Description of the invention

[0007] To resolve one or more of the aforementioned drawbacks, according to a first embodiment, a method for managing the speed of a motor vehicle traveling on a road, the method being implemented by a processor, comprises the steps of: • detection of a first and second vehicle preceding the motor vehicle on the traffic lane; • determining an instantaneous speed of the motor vehicle such that it maintains a first predetermined safety distance from the first vehicle and a second predetermined safety distance from the second vehicle; and • The determination of speed includes sub-steps of determining the acceleration associated with maintaining safe distances from each of the vehicles and selecting the smallest acceleration.

[0008] Thus, the speed variations are reduced.

[0009] Specific features or embodiments, usable alone or in combination, are: • Determining the speed includes calculating a speed profile that allows the motor vehicle to approach within the second safe distance of the second vehicle; and / or • The speed profile is calculated so that the motor vehicle gets within the second safe distance of the second vehicle within a predetermined maximum time.

[0010] In a second embodiment, a device includes a memory associated with at least one processor configured to implement the method of the first embodiment.

[0011] In a third embodiment, a motor vehicle comprises a device according to the second embodiment

[0012] In a fourth embodiment, a computer program includes instructions which, when the program is executed by the device according to the second embodiment, lead the device to implement the process according to the first embodiment. Brief description of the figures

[0013] The invention will be better understood upon reading the following description, given solely by way of example, and with reference to the figures in the appendix in which: • [Fig.1] represents a top view of a vehicle comprising a speed management system according to one embodiment; • [Fig.2] represents, in the form of a top view, three successive moments of a traffic situation; • [Fig. 3] represents a flowchart of a speed management process according to one embodiment; and • [Fig.4] represents a diagram of the acceleration as a function of time of two behaviors, one of which corresponds to the process of [Fig.3]. Methods of implementation

[0014] The terms "front", "rear", "top", "bottom", "transverse" are understood in relation to the vehicle.

[0015] Fig. 1 represents an example of a speed management device 101 included in a vehicle 103.

[0016] This device 101 can take the form of a housing comprising printed circuits, any type of computer or even a mobile phone ("smartphone"). This device is sometimes called a computer or ECU (from the English acronym "Electronic Control Unit").

[0017] The device 101 includes a random access memory 105 for storing instructions for the implementation by a processor 107 of at least one step of the process as described below. The device also includes a mass storage 109 for storing data intended to be retained after the implementation of the process.

[0018] The device 101 may further include a digital signal processor (DSP) 111. This DSP 111 receives data to shape, demodulate and amplify, in a manner known per se, this data.

[0019] The device 101 also includes an input interface 113 for receiving the data implemented by the process described below and an output interface 115 for transmitting the data implemented by the process.

[0020] For example, the input interface 113 can receive the following data: vehicle position or geographical location, vehicle speed and / or acceleration, setpoint or predetermined positions / speeds / accelerations, engine speed, position and / or travel of the clutch, brake and / or accelerator pedal, detection of other vehicles or objects, position or geographical location of other vehicles or objects detected, speed and / or acceleration of other vehicles or objects detected, operating states of sensors, confidence index of data from or processed by sensors and / or devices similar to device 101.

[0021] For example, sensors capable of providing data include: GPS, with or without mapping, tachometers, accelerometers, RADAR, LIDAR, lasers, ultrasound, cameras... In particular, device 101 is connected to a detector 117 located at the front of vehicle 103 and configured to detect the presence of the vehicle(s) preceding vehicle 103. Detector 117 is also capable of determining the distance and relative speed of these vehicles with respect to vehicle 103. For example, detector 117 includes a lidar with a Doppler function.

[0022] The input interface 113 can thus receive the following data: the distance and relative speed of the vehicles preceding the vehicle 103 on the traffic lane.

[0023] The output interface 115 can transmit data similar to the data received by the input interface 113. In particular, the output interface 115 can transmit speed commands to the vehicle drive group 103 and braking commands to the brakes.

[0024] Data transfer between the different elements is preferably carried out by a CAN (for "Controller Area Network") or LIN (for "Local Interconnect Network") type data bus.

[0025] In order to illustrate the operation of the device 101, [Fig.2] shows a road situation in the form of three diagrams A, B and C in which the device 101 implements the process described below.

[0026] In diagram A, vehicle 103 is preceded on traffic lane 201 by a first vehicle 203 and a second vehicle 205, the latter driving in front of the first vehicle 203.

[0027] In diagram B, the first vehicle 203 leaves the traffic lane 201 to go onto the left lane 207, either to overtake the second vehicle 205, or to change direction to the left.

[0028] In diagram C, the first vehicle 203 is driving on the left lane 207 and the vehicle 103 is located behind the second vehicle 205.

[0029] The speed management process implemented by device 101 is then as follows, [Fig.3].

[0030] In a step 301, the device 101 detects, with the detector 117, the presence of the first vehicle 203 and the second vehicle 205 in the configuration of diagram A of [Fig.2],

[0031] In step 303, the device 101 determines the instantaneous speed of vehicle 103 so that it maintains a predetermined safety distance from the two vehicles 203 and 205 preceding it. This safety distance is determined based on the speeds of the vehicles and their braking capabilities to ensure that, even in an emergency, vehicle 103 can stop without touching the vehicles in front of it. This instantaneous speed also changes according to the speeds of vehicles 203 and 205. If they slow down, vehicle 103 will slow down, and if they accelerate, vehicle 103 will accelerate until it eventually reaches its set speed.

[0032] It is noted that, in the situation of diagram A, the predominant safety distance is that associated with the first vehicle 203 in that it is closest to vehicle 103.

[0033] The device 101 then transmits, in step 305, the speed thus determined to the vehicle 103 so that the latter applies it.

[0034] In a conventional operation, when the first vehicle 203 begins to leave lane 201 to join lane 207, for example by accelerating to overtake the second vehicle 205, diagram B of [Fig.2], the device 101 determines on the one hand that it must make the vehicle 103 accelerate to maintain the safety distance with the first vehicle 203.

[0035] When the first vehicle 203 is on lane 207, diagram C of [Fig.2], the device 101 no longer follows the vehicle 203 and adapts the speed to maintain the safety distance with the second vehicle 205.

[0036] It is understood that if the device 101 determines its speed only in relation to the first vehicle 203 during the situation of diagrams A and B, and then in relation to the second vehicle 205 during the situation of diagram C, the vehicle risks accelerating strongly to follow the first vehicle 203 and then braking to adapt to the speed of the second vehicle 205.

[0037] In order to minimize this effect, in the embodiment described, to determine the speed of vehicle 103, device 101 determines, step 307, the acceleration performed with respect to each of the two vehicles 203, 205, device 101 selects, step 309, the smallest acceleration which will most often be that associated with the second vehicle 205.

[0038] Figure 1 illustrates a system according to certain embodiments. The breakdown presented is for pedagogical purposes to highlight the different functions. However, it is understood that each block can be implemented using different means or combinations thereof, such as hardware components, software, one or more computers, and / or electronic circuits. Each component may include at least one computer or a control unit. At least one memory may be included in each component. The memory may include computer program instructions or software code.

[0039] The computers can be implemented by any type of data processing device, such as a central processing unit, a signal processing unit, a specific application integrated circuit, a programmable gate network, etc. The computers can be implemented in the form of a single controller, or a plurality of controllers or computers.

[0040] The different modules are connected to each other by data links adapted to the environment. These can be wired, electrical or optical, or wireless.

[0041] For the software, the implementation may comprise modules or units distributed in the form of procedures, functions, etc. The memories may be any type of storage circuit. They may be part of the processor circuit, or separate from it and connected via electrical data links. These may be non-volatile memories, hard drives, RAM, flash memory, etc.

[0042] The software product can be downloaded from a communication network and / or stored on a computer-readable medium. It can be directly executable by a processor or be in the form of a high-level language requiring one or more intermediate operations to be executable.

[0043] Thus the program instructions stored in memory and processed by the computers can be any type of program code, for example, a compiled or interpreted program written in a suitable programming language.

[0044] The computer program instructions stored in memory are such that, when executed by the computer, the latter carries out one or more of the steps of the processes described above.

[0045] The invention has been illustrated and described in detail in the drawings and the preceding description. This description is to be considered illustrative and given by way of example and not as limiting the invention to this single description. Numerous embodiments are possible.

[0046] For example, the process has been described as a sequence of steps. Some steps can be carried out in parallel or in a different sequence.

[0047] In a first variant, the second vehicle is only taken into account after the detection that the first vehicle is changing lanes, either by detection of the turn signal, or by the offset position to the left of the first vehicle.

[0048] In a second embodiment, the speed determination involves calculating an instantaneous speed profile that allows the vehicle to approach the second vehicle to within a safe distance. Such a speed profile, in the form of an acceleration-time graph, is illustrated in [Fig. 4]. Curve 401 shows a "classic" profile in which the presence of the second vehicle is only taken into account in the situation shown in diagram C of [Fig. 2], and curve 403 illustrates a profile when the method described above is implemented. It can be seen that the initial acceleration is smaller and that there is no braking phase 405 (indicated by curve 401 passing into negative values). acceleration). Thus the profile associated with curve 403 minimizes, or even eliminates, braking deceleration.

[0049] In a third variant associated with the second variant, the device may have a predetermined maximum time setting to reach the safety distance and establishes its speed profile according to this allotted time.

Claims

Demands

1. A method for managing the speed of a motor vehicle (103) traveling on a traffic lane, said method being implemented by a processor and comprising the steps of: • detecting (301) a first and a second vehicle preceding the motor vehicle on the traffic lane; • determining (303) an instantaneous speed of the motor vehicle such that the latter maintains a first predetermined safety distance with the first vehicle and a second predetermined safety distance with the second vehicle; and • the determination of the speed includes substeps of determining (307) the acceleration associated with maintaining the safety distances with each of the vehicles and selecting (309) the smallest acceleration.

2. A method according to claim 1, wherein the determination of speed includes calculating a speed profile enabling the motor vehicle to approach within the second safe distance of the second vehicle.

3. Method according to claim 2, wherein the speed profile is calculated so that the motor vehicle approaches the second safe distance from the second vehicle in a predetermined maximum time.

4. Device (101) comprising a memory associated with at least one processor configured to implement the method according to one of the preceding claims.

5. Motor vehicle comprising the device according to the preceding claim.

6. Computer program product comprising program code instructions which, when the program is executed by the device according to claim 4, cause the device to implement the method according to any one of claims 1 to 3.

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