Classifications

• • G—PHYSICS
  • G08—SIGNALLING
  • G08G—TRAFFIC CONTROL SYSTEMS
  • G08G1/00—Traffic control systems for road vehicles
  • G08G1/16—Anti-collision systems
  • G08G1/167—Driving aids for lane monitoring, lane changing, e.g. blind spot detection

Definitions

• the invention relates to a method of assisting in driving a motor vehicle, in particular in the event of a restart in a line of stationary vehicles, as well as an implementation system.
• ACC Adaptive Cruise Control
• the vehicle which monitors the previous target vehicle, with the aim of automatically keeping a safety distance between it and this target.
• a minimum speed fixed at around 40 km / h
• the driver can select a cruising speed, via a manual steering wheel control.
• the vehicle speed then stabilizes on this setpoint.
• the vehicle being equipped with a radar, intended to detect the vehicles which are located in front of it, if a slower vehicle is detected on the same traffic lane, the system automatically modulates the speed of the equipped vehicle to adapt its distance to the target vehicle .
• this information is sent to a control computer which controls the air intake throttle, the gearbox and possibly the brakes in order to act on the acceleration of the vehicle.
• the driver is informed at any time about the state of the system via a dedicated interface.
• a current ACC system does not make it possible to warn the driver, whose vehicle is stationary in a queue, as soon as the road is clear to restart, and who therefore does not optimally have these "dead times".
• the present invention aims to resolve these drawbacks by proposing a driving assistance method which automatically detects the situations of stopping of the vehicle equipped behind another vehicle, then then detects, also automatically, the actions of the preceding vehicle to authorize restart by the driver.
• a first object of the invention is a method of assisting in driving a motor vehicle equipped with a system comprising an electronic control computer, receiving information delivered by a vehicle speed sensor, by a rangefinder detecting target vehicles located at the front of the vehicle, and intended to carry out the steps of the method, characterized in that it comprises the following steps:
• the determination of a stop situation for the equipped vehicle, behind a target vehicle is obtained from the zero speed state of the equipped vehicle, the distance and the speed relative between the two following vehicles, and their immobilization time.
• the determination of clear lane information is obtained by detection of a displacement of the target vehicle beyond a predetermined threshold, or else by detection of both a relative speed and a relative acceleration of the target vehicle with respect to the immobilized equipped vehicle above predefined thresholds.
• the vehicle being equipped with a driving assistance system comprising a device for immobilizing the accelerator pedal in an inactive position
• the driving assistance method comprises following steps: - determination of a stop situation for the equipped vehicle, behind a target vehicle;
• a second object of the invention is a system for implementing said driving assistance method.
• the vehicle must be equipped with a system comprising an electronic control computer 5 receiving information from a vehicle speed sensor 1, which makes it possible to detect the stop or the starting of the vehicle, and of a range finder 2 which detects target vehicles situated in front of the equipped vehicle and determines the position, the speed and the relative acceleration of the target vehicles with respect to the equipped vehicle which follows them.
• a vehicle speed sensor 1 which makes it possible to detect the stop or the starting of the vehicle
• a range finder 2 which detects target vehicles situated in front of the equipped vehicle and determines the position, the speed and the relative acceleration of the target vehicles with respect to the equipped vehicle which follows them.
• the method according to the invention consists first of all in determining, under certain conditions, whether the vehicle thus equipped with the driving assistance system is stopped behind another vehicle, said system being activated.
• the rangefinder tracks the movements of the previous vehicle, so that the electronic computer determines, according to certain conditions of distance, speed and relative acceleration between the two vehicles, if the traffic lane has become clear again, authorizing a restart of the equipped vehicle .
• the process signals this to the driver who can thus restart safely.
• the system can be put into service or out of service, from a selection interface 3 by the driver or automatically. It may further comprise a device 4 for immobilizing the accelerator pedal, as described in French patent application No. 96 13944 in the name of RENAULT, controlled by the computer 5.
• This device immobilizes the pedal in an inactive situation, where the control member for the admission of gases into the engine can be placed directly under the control of the control computer of the driving assistance system, on board the vehicle.
• this device comprises a movable element connected to the pedal, which is moved by the latter between a first position in which the pedal is immobilized in its inactive position, kept as long as the driver's thrust on the pedal remains less than one pre-established effort threshold, and a second position for disabling the assistance system where the pedal has no particular resistance. This last position is joined as soon as said force threshold is exceeded by the driver who can again control the opening of the gases.
• such a device performs a footrest function, by creating a hard point in the travel of the accelerator pedal, this function of course being disengageable.
• the method when the method has determined a stop situation for the equipped vehicle, in a queue of vehicles, it activates the disengageable hard point function in the stroke of the accelerator pedal to immobilize it.
• the method deactivates the hard point position for the accelerator pedal, whether the driver has his foot on it or not. If the driver actually has his foot on the pedal in the footrest position when this function is disengaged, he will feel an effect under the foot signaling that the way is clear.
• FIG. 2 is an example of a flow diagram of execution of the different steps of the method according to the invention.
• the first step (a) concerns the activation of the driver assistance system.
• This activation can be done by the driver of the vehicle via a manual interface, for example a button, dedicated to this function. It can also be obtained from the activation commands of a speed or distance regulation system when the vehicle is equipped with it.
• the two distance and speed regulation functions being active only beyond a speed threshold of 40 km / h for example, it is considered that the method according to the invention constitutes the extension of their use for zero speeds.
• step (a) the activation of the system is automatic from operating conditions of the vehicle observed in the following step (c).
• step (b) of initializing the process consists in zeroing a counter, of which the role will be to count down the time during which the equipped vehicle is stopped behind a vehicle.
• step (c) makes it possible to recognize whether the vehicle is in a stop situation, by reading the speed of the wheels delivered by a sensor. If the vehicle is not stopped, the method returns to step (b) of zeroing the counter.
• step (d) detects the presence of a target in front of said vehicle, on its lane.
• the rangefinder delivers relative distance and speed information which are then compared respectively to two predetermined thresholds S d and S v .
• the method therefore compares the relative distance between the equipped vehicle and the target vehicle detected to a maximum threshold S ⁇ , of the order of 6 meters for example, below which the system is sure not to take account of erroneous obstacles such as a roundabout or a parked vehicle behind which the equipped vehicle parks.
• the method relates only to driving in line.
• the method also compares the speed relative to a maximum threshold S ⁇ , to ensure that the target vehicle is itself stopped, or even reverses slightly.
• step (e) counts the time spent at a stop behind a target vehicle itself immobilized. This count is obtained by incrementing the counter, which will be compared in the following step (f) with a minimum time value m ⁇ n , which can be configured and adapted, to be observed in order to determine a real stopping situation behind a vehicle. This minimum time is of the order of 1.5 seconds, necessary to activate the assistance offered by the process.
• Step (g) relates to the determination of a stopping situation, as soon as the conditions for stopping in line behind a target vehicle have been met for a period defined in step (f). Thus, the vehicle is immobilized, until the computer restarts.
• Step (h) for this purpose consists in measuring the distance between these two vehicles and in comparing it with a minimum distance threshold S D , of the order of 8 meters for example.
• This minimum distance threshold S D can be calibrated according to the driving style of the driver of the vehicle thus equipped and the state of road traffic.
• step (i) the method proceeds to step (i) of determining "free lane" information for the equipped vehicle.
• step (k) the driver is warned that the way is clear, and that he can restart safely, in particular by a man / machine interface, such as an audible signal, light information or tactile information. noticeable by the driver at the steering wheel.
• the method performs in step (j) two comparisons, one of the relative speed of the two vehicles and the other of the acceleration of the target vehicle by compared to the equipped vehicle. It first checks whether the relative speed is greater than a minimum calibratable Sy threshold, of the order of 1.5 m / s, corresponding to the distance from the target car at a speed greater than Sy.
• step (i) it checks whether the relative acceleration is greater than a calibrated minimum threshold S A , of the order of 2.6 m / s 2 , so that the driver reacts without delay to the restart of the vehicle in front, depending of its starting acceleration. If these two comparisons are positive, the method proceeds to step (i) already described previously and then signals to step (k).
• step (g) corresponds to activation a disengageable hard point immobilizing the accelerator pedal in the high position, when the conditions for stopping in line behind a vehicle have been observed for a sufficient time, defined in step (f).
• This hard point position allows the driver rest your foot on the pedal without affecting the control of the air intake in the engine.
• step (i) of determining free lane information in front of the stopped equipped vehicle the method performs deactivation of the hard point in the travel of the accelerator pedal. This automatic disengagement of the hard point makes it possible to warn the driver that he can again move his vehicle forward, since his lane is clear.
• the method according to the invention thus makes it possible to assist the driver in a traffic jam situation, in road traffic, by signaling to him that the lane becomes free to restart without the need to constantly monitor the road scene.
• the invention can be incorporated into it without additional cost or additional specific means.
• the invention also makes it possible to perform a footrest function for the driver, at the disengageable hard point of the accelerator pedal. It applies to any type of vehicle, automobile or industrial, utility, bus or truck.

Landscapes

• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Control Of Driving Devices And Active Controlling Of Vehicle (AREA)
• Control Of Vehicle Engines Or Engines For Specific Uses (AREA)
• Controls For Constant Speed Travelling (AREA)
• Radar Systems Or Details Thereof (AREA)
• Traffic Control Systems (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=9532316

Family Applications (1)

Country Status (6)

Families Citing this family (7)

Family Cites Families (3)

• 1998
  • 1998-11-03 FR FR9813825A patent/FR2785433B1/fr not_active Expired - Fee Related
• 1999
  • 1999-10-28 WO PCT/FR1999/002624 patent/WO2000026885A1/fr active IP Right Grant
  • 1999-10-28 DE DE69904747T patent/DE69904747T2/de not_active Expired - Lifetime
  • 1999-10-28 ES ES99950856T patent/ES2186416T3/es not_active Expired - Lifetime
  • 1999-10-28 JP JP2000580188A patent/JP2002529834A/ja not_active Withdrawn
  • 1999-10-28 EP EP99950856A patent/EP1127344B1/de not_active Expired - Lifetime

Non-Patent Citations (1)

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