The invention relates to a method for driving speed control
a vehicle, wherein a maximum permissible driving speed
depending on a course of the vehicle ahead route
From the DE 199 52 392 A1
A method and apparatus for providing route-dependent driver information to a driver of a vehicle is known. In this case, a course of a distance to be traveled by the vehicle is determined at least in regions in a forward-looking manner and at least relative to the current vehicle position. A current driving state, for example a current driving speed or an acceleration, of the vehicle is ascertained, at least one limit condition for the driving state is determined, which enables a safe passage through an area of the route to be traveled ahead of the vehicle, and generates at least one route-dependent warning information, if the current driving condition does not meet the at least one boundary condition.
In addition, in the DE 198 48 236 A1
discloses a method and apparatus for limiting a speed of a vehicle. In the course of an iterative process, a setpoint speed is determined as a function of vehicle speed, maximum lateral acceleration and curve radius. The setpoint speed approaches a limit speed with which the curve to be traveled can be safely traversed. The vehicle speed is controlled depending on this target speed and an actual speed.
Invention is based on the object, a relation to the
State of the art improved method for driving speed control
indicate, based on which a curve on a vehicle ahead
Route can be passed safely.
Task is according to the invention in terms of
A method by the in claim 1 and in terms of the device
solved by the features specified in claim 5. advantageous
Further developments of the invention are the subject of the dependent claims.
inventive method for driving speed control
of a vehicle provides that a maximum allowable
Driving speed depending on a course of a
the route ahead of the vehicle. According to the invention
the maximum permissible travel speed for at least
an area of the route ahead in dependence
a current driving speed, a curvature of the road,
a road friction coefficient, a vehicle mass and a limit value
for a resulting from cornering centripetal force
the process of the invention is in profit
bringing a driving comfort for a vehicle occupant
increased, since the maximum permissible driving speed
depending on a resulting from cornering
Transverse acceleration is determined and thereby acting on the vehicle occupant
Centripetal force, also called transverse force, as not unpleasant
becomes. For this purpose, the current driving speed of the vehicle
delayed to the maximum permissible travel speed,
the delay being particularly advantageous
not done abruptly.
Increasing driving comfort and driving safety
the fuel consumption of the vehicle is reduced because the driving speed
of the vehicle in a particularly advantageous manner anticipatory regulated
In addition, driving safety is increased because the respective area
the route ahead with an adjusted driving speed,
the maximum permissible driving speed, is traversed.
The invention will be explained in more detail with reference to a drawing.
1 schematically a program flowchart of the method according to the invention for driving speed control of a vehicle.
corresponding parts are in the figure with the same reference numerals
In 1 a program flowchart of the method according to the invention for vehicle speed control of a vehicle is shown.
In particular, the method according to the invention is initiated when a need for an intervention with regard to a current driving speed v Fzg of the vehicle, in particular before cornering, is detected.
For example, the vehicle has one
automatic cruise control device.
is provided that by means of at least one detection unit
E an environment identifier U of the vehicle, such as a camera,
a radar sensor, a lidar and / or a photonic mixer,
a distance ahead of the vehicle is detected.
or additionally may be for detecting the vehicle ahead
Route also a navigation system N can be used.
If the vehicle on the road ahead at least a curve ahead of the E of the environment recognition is located in the detection area of the detection unit U, are in an advantageous manner a road curvature c 0, hereafter referred to as curvature c 0 denotes optionally a curve change of curvature c 1 and a distance d detected at a Kurvenkurümmungspunkt and a signal processing S a control unit SE supplied.
Curvature point denotes a so-called
Vorschauort, where the forecast location in the distance d to
the vehicle, in particular to the position of the detection unit
E, the environment identifier U is located.
In addition, the instantaneous travel speed v Fzg of the vehicle is determined as a further input variable for carrying out the method according to the invention. The current driving speed V Fzg can be read in , for example via an engine control unit of the vehicle.
In the present exemplary embodiment, the instantaneous driving speed v Fzg is, in particular, a desired driving speed v Fzg set which is predetermined for the speed control device of the vehicle via the vehicle driver.
The detected signals with respect to the curvature of curve c 0 , possibly the curvature change c 1 and the distance d to the curvature point and the instantaneous vehicle speed V Fzg are the signal processing S supplied, wherein a sensor data fusion for predicting a curve is performed on the vehicle ahead route.
In the control unit SE, for example, in the control unit of the cruise control device, a characteristic field K is deposited, which at least a maximum permissible vehicle speed v max as a function of the curve curvature c 0 and a limit for a resulting from cornering with a corresponding curve curvature c 0 centripetal force, ie a acting on a vehicle occupant lateral force F Q , wherein the limit is hereinafter referred to as Grenzquerkraft F transverse, boundary comprises.
the characteristic field K was empirically determined on the basis of driving tests.
The lateral force F Q
acting on the vehicle, in particular on the vehicle occupants, can be determined, for example, as follows:
m vehicle mass,
r radius, wherein the radius of the reciprocal of the curvature c is 0
Preferably, the characteristic field K further acts on a curve sizes, such. B. the vehicle mass m and / or a Fahrbahnreibwert k my , with a possible procedure for determining the vehicle mass m and the Fahrbahnreibwertes k my is described in more detail below.
If the determined instantaneous driving speed V Fzg of the vehicle is less than a maximum permissible driving speed v max dependent on the detected curve curvature or if the instantaneous driving speed v Fzg is the same value as the maximum permissible driving speed v max , then the driving speed control for cornering becomes corresponding the current driving speed V Fzg regulated and / or controlled, wherein a delay a Fzg, delay , ie a negative acceleration of the vehicle is 0.
In one possible embodiment of the method according to the invention, the maximum permissible driving speed v max can be determined mathematically / physically as an alternative or in addition on the basis of the detected signals, which can be fed to an evaluation unit of the control unit SE, for example.
The maximum permissible travel speed v max
in relation to the forecast location at a distance d taking into account the vehicle mass m results, for example, from the following equation:
maximum permissible travel speed,
road friction coefficient,
k (v veh
) vehicle speed dependent factor,
F quer, Grenz
m vehicle mass, and
The driving speed-dependent lateral lateral force F transverse, limit is determined by a driving-speed-dependent factor k (v Fzg ) and, if appropriate, information relating to a road friction coefficient k my , which is determined, for example, by at least one detection unit E arranged on the vehicle.
Furthermore, the driving speed-dependent lateral lateral force F is transverse, limit of the vehicle mass m dependent. A vehicle empty weight is specified as known and stored for example in the control unit SE, for example, the speed control device, wherein a load of the vehicle, for example by means arranged on an air suspension spring travel sensors and / or arranged on vehicle axles axle load sensors are determined or will. The vehicle mass m is thus determined preferably based on the vehicle idle weight plus the load of the vehicle.
Laying down the side load F transversely boundary may be provided on the one hand that this is preset or it may alternatively be provided that the lateral limit force F transversely boundary is chosen by the driver himself.
In one possible embodiment of the method according to the invention, when determining the lateral transverse force F transverse, limit , a center of gravity position and a resulting rolling motion of the vehicle can also be taken into account.
If the value of the instantaneous driving speed v Fzg
does not correspond to the value of the maximum permissible driving speed v max
determined on the basis of the characteristic field K and / or the mathematical derivation, or is the value of the instantaneous driving speed v Fzg
greater than the maximum permissible driving speed v max
for the vehicle
Cornering, so the deceleration a Fzg, deceleration of
the vehicle, the negative acceleration, for example, determined by the following equation:
a vehicle, delay
delay, negative acceleration,
maximum permissible travel speed,
instantaneous driving speed, and
d distance of the vehicle, in particular distance of the detection unit E of the surroundings identifier U to the preview location.
In this case, the deceleration a Fzg, deceleration represents a function of the maximum permissible travel speed v max for the forecast location at a distance d and the instantaneous vehicle speed v Fzg of the vehicle.
The determined value of the deceleration a Fzg, delay is supplied to the control unit SE functional interfaces for actuators SG, for example, a turn-off air compressor LV, a turn-off generator G and / or a device V for energy recovery, especially in a hybrid vehicle supplied.
In this case, the delay a Fzg, delay of the vehicle in a particularly advantageous manner is not carried out abruptly.
The inventive method can be referred to as a predictive cruise control, the vehicle speed control, for example, by the driver for a straight ahead driving speed v Fzg, set controls and / or regulates, and the current vehicle speed V Fzg of the vehicle when cornering on the maximum for cornering permissible travel speed v max delayed.
In a particularly advantageous manner, at the maximum permissible driving speed v max, the lateral force F Q acting on the vehicle driver from the cornering is taken into account, it being possible to provide that the lateral lateral force F transverse, limit is predetermined or predetermined by a vehicle driver.
the method according to the invention is a driving safety
as well as increased ride comfort, especially when cornering
that a lane course in the longitudinal and lateral direction successively
is predicted. The driving speed of the vehicle is anticipatory
controlled and / or regulated, thereby reducing fuel consumption
of the vehicle can be achieved.
In addition, information about the size of the delay a Fzg, delay the current vehicle speed v Fzg also targeted for an active energy management, for example, from switchable ancillaries to operating strategies of hybrid drives are used.
QUOTES INCLUDE IN THE DESCRIPTION
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Cited patent literature
- DE 19952392 A1 
- - DE 19848236 A1