The invention relates to a method for operating a collision avoidance
or Kollisionsfolgenminderungssystems of a vehicle after the
The preamble of claim 1 and a collision avoidance
or Kollisionsfolgenminderungssystem according to the preamble of claim
are often systems for distance and speed control
known, who not only intervene in a braking maneuver when in doubt,
but even rear-end collisions
and thereby the danger for
to reduce the passengers to a minimum. In this so-called "Collision
Mitigation System "(CMS)
be already before a possible
Collision with a potential collision partner all necessary countermeasures
automatically initiated. So the known CMS calculates the probability
a collision due to driving conditions, a distance to the
preceding vehicle and a relative speed. If necessary, attack
the CMS then independently
to prevent collisions. The time for this
System intervention is based on a necessary target delay as well
on a driver reaction time. Before the system intervention is at the
known CMS activates an optical and / or audible warning function.
However, there is no additional backup function
A generic method or a generic device are from the DE 102 58 617 A1
known. There, depending on the distance between the vehicle and an obstacle and the remaining time until the impact of the vehicle on the obstacle first an optical and / or acoustic driver warning and possibly another haptic driver warning triggered before an emergency braking to avoid the collision with the obstacle or to reduce the consequences of accidents is triggered. The delay achievable during the emergency braking process can either be fixed in the range between 5 m / s 2
and 7 m / s 2
or determined on the basis of variables such as vehicle mass, lining, coefficient of friction, road surface condition, etc.
Invention is based on the object, a further developed method
for operating a collision avoidance or collision sequence mitigation system
of a vehicle as well as an associated improved collision avoidance or
To provide collision sequence mitigation system.
The object is achieved by the
Characteristics of the independent
the method according to the invention,
in which one the remaining time until the impact of
Vehicle determined on an obstacle time duration size.
Achieved the time duration size one
first duration threshold, will be a first warning function and / or
Information function activated. Achieved the time duration size one
second time duration threshold is a system intervention in which
at least one autonomous partial braking is performed. If after reaching
of the first or second time duration threshold, a hazard brake condition
is, then an automatic danger braking or emergency braking
with maximum possible
the danger brake condition becomes a brake pedal position be writing
Pedal position size and at least in
a value range of the pedal position size in addition to the brake pedal speed
descriptive pedal speed variable evaluated. It can
the brake pressure in the wheel brake of the vehicle so far
until at least one of the wheels reaches the blocking limit
The invention therefore only triggers the danger braking process when
the driver requests this by a brake pedal operation satisfying the hazard brake condition
the driver over the sovereignty
the danger braking process. The requirement of the danger braking process
can by evaluating the pedal position size and possibly additionally the
Pedal speed size safe
be determined. To further enhance safety
by the autonomous partial braking already before a possible
Danger braking reduces the kinetic energy of the vehicle.
This can reduce the risk of accidents or at least the consequences of the accident
As the first warning function and / or information function, for example, audible warning signals (eg conspicuous sounds / sounds, voice output or also action recommendations) and / or optical warning signals (eg light signals) can be emitted. Furthermore, visual warning signals, for example optical instructions on the display or representations of the vehicle and the obstacle on the display, and / or also haptic warning signals, for example vibrations or shaking of the steering wheel, are possible. As a haptic warning signal can also be a Gurtzupfen - that is, an alternating tightening and loosening of the driver's seat belt - done, causing the driver particularly insistent on an impending danger awareness of the situation.
Embodiments of the invention will become apparent from the dependent claims and
the description of the figure.
if the danger brake condition is met,
if the pedal position size is one
exceeds first pedal position threshold. It gets away from it
assumed that in this area the pedal position size above
of the first Pedalstellungsschwellenwertes independent of the Pedalgeschwindigkeitsgröße a danger braking process from
Driver is requested.
Danger brake condition can be independent
not from the pedal speed size
if the pedal position size is one
falls below the second pedal position threshold. For a pedal position size below
the pedal position threshold is out of braking
to assume a dangerous situation.
Is it possible,
that the danger brake condition is met when the pedal position size at least
the second pedal position threshold and at most the first pedal position threshold
corresponds and the pedal speed is simultaneously one of the
Pedal position size dependent pedal speed threshold exceeds.
In the range from the second pedal position threshold to the first
Pedal position threshold depends
the danger brake condition in addition
to the pedal position size too
from the pedal speed size. The pedal speed threshold
is not constant in this area, but depends on the
Pedal position size specified.
As a result, there is a very variable default option for the danger brake condition,
which also at driving conditions of the
Vehicle and / or adaptable to the driving behavior of the driver
Pedal speed threshold can depend on
from the pedal position size in sections
be given linear, creating a simple specification of the course
the pedal speed threshold at sufficiently accurate
Adaptability to distinguish pedal operations to request
on the one hand and pedal operations for
Requirement of metered target braking operations on the other hand is possible.
that when checking whether
the danger brake condition is met
is, the vehicle longitudinal dynamics
descriptive longitudinal dynamics variable and in particular
the vehicle longitudinal speed
it is guaranteed that
the current vehicle longitudinal dynamics
during the exam
considered in the danger brake condition
becomes. The driving condition of the vehicle may therefore be in the test of
considered in the danger brake condition
is advantageous when the first pedal position threshold
and / or the second pedal position threshold and / or the pedal speed threshold
from the driving condition of the vehicle such as e.g. from the longitudinal dynamics quantity and in particular
from the vehicle longitudinal speed
are. This makes the distinction between the requirement
of metered target braking processes
and danger braking operations
the driving condition of the vehicle further improved.
may be another upon reaching the second duration threshold
and in particular an occupant fixation, for example in the form
a belt tightening done. By the belt tightening in addition to
Partial braking is warned not only the driver, but at the same time
the safety of the vehicle occupants in the event of an accident increased.
the partial braking deceleration set in the autonomous partial braking process can
in a preferred embodiment of the invention to an amount
be limited below one for a collision avoidance
lies. This has the advantage that the collision avoidance system
can be used as a "distance assistant"
but that to avoid a possible collision an attention level
the driver is required. The partial braking delay can
In this case, for example, be about 90% of a maximum achievable braking deceleration.
is preferably dependent
from the vehicle longitudinal speed
determined. In particular, the partial braking delay with increasing vehicle longitudinal speed
For example, gradually decrease. At low vehicle speeds can
a higher one
be set as at higher
Vehicle longitudinal speeds.
It is advantageous if the system intervention on reaching the second
Duration threshold an autonomous steering intervention takes place. The system intervention
for collision avoidance or Kollisionsfolgenminderung can therefore
designed as an autonomous braking intervention and as an autonomous steering intervention
Upon request by the driver, the system intervention and / or the danger braking process be deactivated. For example, a deactivation threshold value can be determined for deactivating the system intervention or the danger braking process from pedal position size and / or pedal speed variable. In a simple implementation to be realized, the deactivation threshold may be set as a percentage of the pedal position size and may be, for example, -50%, which corresponds to a 50% reduction in the pedal position by shifting the brake pedal toward the brake pedal rest position. Deactivation of the system intervention or of the danger braking process would thus occur in the case of a withdrawal of the brake pedal starting from the current brake pedal position by at least half the current pedal travel in this example.
it is possible
the system intervention triggered upon reaching the second time duration threshold
and / or the danger braking operation by a steering threshold exceeding
Steering wheel movement of the driver is disabled. From such a
the driver is closed on an initiated evasive maneuver.
To the sovereign over the driver
the choice of the appropriate means for accident prevention or accident consequence reduction
the deactivation of autonomously initiated measures takes place.
become the system intervention triggered upon reaching the second time duration threshold
and / or the danger braking process by a longitudinal acceleration triggered by the driver
the deactivation of the system intervention and / or the danger braking process,
may be the audible and / or visual warning or information of the
Drivers are maintained to the remaining danger situation
The invention will be explained below with reference to an embodiment shown in the drawing
explained in more detail. there
1 An embodiment of a collision avoidance or Kollisionsfolgenminderungssystems in block diagram similar schematic representation,
2 a diagram showing the pedal speed over the pedal position size with two exemplified trajectories,
3 a schematic representation of the time course of a driving situation with an approaching to an obstacle vehicle.
In 1 is a block diagram of a collision avoidance and / or Kollisionsfolgenminderungssystems 5 to avoid a rear-end collision or to reduce the consequences of a rear-end collision of a vehicle 6 on an obstacle 7 shown. The collision avoidance and / or collision sequence mitigation system 5 has a distance determining device 12 on. The distance determining device 12 determines a distance D between the vehicle 6 and the obstacle 7 descriptive distance size A. In the preferred embodiment, the distance A is from that in the direction of travel 13 of the vehicle 6 measured distance D of the vehicle 6 to the obstacle 7 educated.
The distance determining device 12 has ambient sensors, for example in the form of a radar, a lidar (Lidar = light detection and ranging), a video sensor and / or an ultrasonic sensor. Particularly preferably, the environmental sensors are designed as a 77 GHz radar sensor, which can have a range between about 7 and 150 m at an opening angle of about 9 °. Alternatively or additionally, 24 GHz radar sensors may also be provided, each of which may have a range of about 0.1 to 30 m at an opening angle of about 45 °, whereby the quality of obstacle detection can be improved. In particular, an improved detection of stationary obstacles is possible. The distance determination device can be part of a vehicle 6 existing, known per se distance control speed device for controlling the vehicle longitudinal speed vx and the distance D to be ahead vehicles.
The distance size A formed by the distance D is determined by the distance determining device 12 to a control unit 16 transmitted. The control unit 16 determined from the distance D and the vehicle longitudinal speed vx - that of the control unit 16 from a longitudinal speed sensor 17 is transmitted - a period size, the remaining time h to the impact of the vehicle 6 on the obstacle 7 indicates. Depending on the amount of time duration or duration h, at least one driver warning is initially produced. This is the control unit 16 with an optical and acoustic driver warning system 19 and a haptic driver warning system 20 connected.
Furthermore, a brake pedal position of a brake pedal 24 of the vehicle 6 descriptive pedal position size px to the control unit 16 transfer. The pedal position size px results example, by the pedal travel ps, the pedal of a sensor 25 is detected, and one in the master cylinder 26 of the brake system 27 of the vehicle 6 generated by the brake pedal position master cylinder pressure pd, of a pressure sensor 28 is measured. In a modification to the preferred embodiment, only one of the two values pedal travel ps or master cylinder pressure pd could be used as the pedal position size px. Other parameters correlated with the brake pedal position, such as the pedal force, could alternatively or additionally serve to form the pedal position size px.
For automatic release of a braking operation, the control unit 16 the brake system 27 to drive, as shown schematically in 1 is shown. It can be independent of the driver by the operation of the brake pedal 24 requested braking deceleration z in one or more of the wheel brake of the brake system 24 a brake pressure or a braking force can be established.
Based on 2 and 3 Now is the timing of the approach of the vehicle 6 to the obstacle 7 also described in the present case by a substantially same direction of travel 13 formed vehicle is formed.
From the remaining time h is in the control unit 16 first determines a first braking time for a collision avoidance by a braking operation with a first braking delay value z0. This first braking time corresponds to a first time duration threshold h0. The first duration threshold h0 is selected to be about 2.0 s to 3.0 s in the preferred embodiment. From this, the first braking deceleration value z0 is then determined, which of other variables such as vehicle longitudinal speed vx, relative speed of the vehicle 6 to the obstacle 7 and distance D to the obstacle 7 depends.
When the remaining time h reaches this first time duration threshold h0, the control unit releases 16 by controlling the visual and audible driver warning system 19 and the haptic driver warning system 20 First, a first warning function with visual, acoustic and haptic driver warning, which warns the driver of the impending collision with the obstacle. The driver is thereby prompted to initiate a braking operation to prevent the rear-end collision. Visual and acoustic driver warnings are known per se and can be configured in many ways.
The haptic driver warning system becomes the haptic driver warning system 20 triggered, for example, causes a Gurtzupfen on the driver's seat belt. The driver's seatbelt is alternately cocked and released again. Other haptic driver warnings such as vibration of the steering wheel or the driver's seat can by the haptic driver warning system 20 to be triggered.
Modification to the illustrated embodiment, the
visual, acoustic and the haptic driver warning also in time
triggered one after the other
become and so to speak different escalation levels of the driver warning
If the driver does not respond, or only insufficiently, so that the risk of collision still exists when the remaining time h has reached a second time duration threshold h1, the control unit will respond 16 for further haptic driver warning and for reducing the kinetic energy of the vehicle 6 the service brake system 27 controlled and set a partial braking operation with a predetermined partial braking force or a predetermined partial braking delay z1.
In the preferred embodiment, the partial braking delay z1 is up to 90% of a maximum achievable braking delay z, wherein the partial braking delay z1 is specified depending on the vehicle longitudinal speed vx. As the vehicle longitudinal speed vx increases, the predetermined partial braking delay z1 decreases in stages. By way of example, at partial vehicle longitudinal speeds vx up to about 50 km / h, a partial braking deceleration of about 4 m / s 2 is set, at vehicle longitudinal speeds vx from about 50 km / h to about 150 km / h a partial braking deceleration of about 3 m / s 2 and at vehicle longitudinal speeds from about 150 km / h a partial braking delay of about 2m / s 2 . The partial braking deceleration z1 set during the partial braking process is selected so that it is smaller in magnitude than the nominal deceleration that would be necessary at the time of reaching the second time duration threshold h1 at the current vehicle longitudinal speed vx, the current distance D of the vehicle 6 to the obstacle 7 and the current relative speed between the vehicle 6 and obstacle 7 a drive onto the obstacle 7 to prevent. This will misuse the collision avoidance or collision avoidance system 5 as means for adjusting the distance to a preceding vehicle prevented. The responsibility to initiate necessary measures to end or prevent dangerous situations in traffic therefore remains with the driver.
The second time duration threshold h1 can For example, be chosen so that up to the last possible time, to which by a steering intervention or braking intervention, a collision of the vehicle 6 with the obstacle 7 can be avoided, nor a predetermined period of action remains, which is about 1.0 s to 2.0 s in the embodiment.
A second time duration threshold h1 is also reached
an occupant fixation of the vehicle occupants in the form of a reversible belt tightening
as a further safeguard.
An alternative embodiment of the invention may also provide an automatic steering intervention in addition to the partial braking process, with the aim of the vehicle 6 at the obstacle 7 to steer past the accident avoidance or the vehicle 6 in terms of the obstacle 7 to be aligned in such a way that in the event of a rear-end collision, the consequences for the accident participants are as small as possible. This requires knowledge of the position, orientation and nature of the obstacle 7 required, which can be obtained, for example, from the data of an object recognition device.
After reaching the first or second duration threshold h0 or h1, the control unit checks 16 whether a given hazard brake condition is met. If so, the control unit controls 16 the brake system 27 of the vehicle 6 and triggers a hazard braking operation with the maximum achievable braking deceleration zmax. At the in 3 This is illustrated by way of example at a time when the remaining time h takes on the time duration value h2. In this case, the braking force or the brake pressure in the wheel brake of the vehicle 6 increases until at least one of the braked vehicle wheels has reached its blocking threshold and a known anti-lock control - such as ABS - engages.
The danger brake condition is determined by the pedal position size px and
one from the temporal change
the pedal position size px
Pedal speed size pv tested.
2 shows a coordinate system, where the abscissa indicates values for the pedal position size px and the ordinate values for the pedal speed variable pv. The origin of the coordinate system is marked with U. Positive values of pedal speed pv mean that the brake pedal 24 from its unoperated home or rest position, while negative values of the pedal speed pv indicate a return movement of the brake pedal 24 describe from a deflected, actuated position back to the unactuated initial position. The starting position of the brake pedal 24 is indicated by the origin U of the coordinate system.
With the help of driving tests was determined that by a driver by pressing the brake pedal 24 caused dosed target braking operations on the one hand and danger braking operations on the other hand can be distinguished on the basis of the resulting trajectories in Pedalstellungsgrößen pedal speed variable coordinate system. The trajectories always begin and end in the origin U of the coordinate system. In 2 are a first trajectory describing a metered target braking process 30 and a second trajectory characterizing a danger braking process 31 for a vehicle longitudinal speed of about 50-70 km / h exemplified.
From the driving tests it has become apparent that the coordinate system is in a target braking range 33 and a danger zone 34 divide, with the two areas 33 . 34 change depending on the vehicle's longitudinal speed. The first range limit shown as a solid line 35 applies to vehicle longitudinal speeds of about 50-70 km / h.
In this speed range arise for metered target braking operations trajectories, which are essentially in a range section 38 of the target braking area 33 extending from the origin U along the abscissa to an end point 39 extends and is formed approximately symmetrically to the abscissa. The width of the area section seen transversely to the abscissa 38 increases from the origin to a maximum width and then decreases first stronger and then weaker to the end point 39 out.
The hazard brake condition is met when the pedal operation of the brake pedal 24 descriptive trajectory the target braking range 33 at least at one point leaves. The danger brake condition is fulfilled, for example, independently of the pedal speed variable pv when the pedal position quantity px exceeds a first pedal position threshold px1. A pedal position amount px whose amount is greater than the first pedal position threshold px1 exceeds the first range limit 35 ,
If the amount of the pedal position amount px is smaller than a second pedal position threshold px2, then the danger brake condition is not satisfied regardless of the pedal speed pv. The trajectory then always runs in the target braking range 33 ,
If the pedal position size at least the second pedal position threshold px2 and at most the first pedal position threshold px1, the danger braking condition is met only if at the same time the pedal speed value pv exceeds a pedal speed threshold pvs dependent on the pedal position size px.
The pedal speed threshold, pvs, is positive and decreases with increasing values of the pedal position size px. In the preferred embodiment, the pedal speed threshold pvs depending on the pedal position size px sections linearly and has here two sections each having a constant slope, wherein a first section 40 starting from the second pedal position threshold px2 with increasing pedal position size px falls in magnitude more than an adjoining second section 41 which ends at the first pedal position threshold px1.
For a higher vehicle longitudinal speed vx results in a second range limit 45 , which is shifted in terms of magnitude larger values of the pedal position size, the basic course is maintained. The second range limit may be, for example, by multiplying the first range limit 35 be obtained with a factor. This results in a modified first and second pedal position threshold px1 'bzw., px2'.
The system intervention triggered by reaching the second time duration threshold value h1 and the danger braking process can be deactivated again in the exemplary embodiment if an abort criterion is met. The termination criterion is then fulfilled if a longitudinal acceleration of the vehicle triggered by the driver 6 is detected. For example, the control unit 16 For this purpose, the accelerator pedal position or the signal of a longitudinal acceleration sensor are transmitted.
To meet the termination criterion, a deactivation threshold for the pedal position size px is also specified. For example, the deactivation threshold is -50% so that the abort criterion is met when the pixel size px has decreased by 50%. So if the brake pedal 24 is moved in the direction of its initial or rest position and the pedal position size has thereby reduced by at least 50%, the termination criterion is met.
Furthermore, in an alternative embodiment, the termination criterion can also be satisfied if a steering wheel movement of the driver exceeding a steering threshold value is determined. The steering wheel movement can be described by the steering wheel angle and / or the steering wheel torque and / or a time derivative of these variables. This would require the control unit 16 at least one of these the steering wheel movement descriptive quantities are transmitted.
Furthermore, the abort criterion is met when the driver is using the collision avoidance or collision sequence mitigation system 5 switches off by a corresponding operation, which can be done for example by a corresponding menu selection in a vehicle instrument. When the distance determining device 12 has a fault or the obstacle can not be reliably detected, the termination criterion is also met.
the termination criterion the deactivation of the system intervention and / or
the danger braking operation is carried out, the acoustic and / or
optical and / or haptic warning or information of the driver
remain maintained, especially as long as the first time threshold
h0 due to a changed driving condition
or an altered one
Traffic situation was not fallen below again.