WO2020057854A1 - Procédé de commande d'un véhicule pendant un freinage mu-split, système de commande et véhicule - Google Patents

Procédé de commande d'un véhicule pendant un freinage mu-split, système de commande et véhicule Download PDF

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Publication number
WO2020057854A1
WO2020057854A1 PCT/EP2019/071436 EP2019071436W WO2020057854A1 WO 2020057854 A1 WO2020057854 A1 WO 2020057854A1 EP 2019071436 W EP2019071436 W EP 2019071436W WO 2020057854 A1 WO2020057854 A1 WO 2020057854A1
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WO
WIPO (PCT)
Prior art keywords
vehicle
braking
split
mue
steering
Prior art date
Application number
PCT/EP2019/071436
Other languages
German (de)
English (en)
Inventor
Klaus PLÄHN
Original Assignee
Wabco Gmbh
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Wabco Gmbh filed Critical Wabco Gmbh
Publication of WO2020057854A1 publication Critical patent/WO2020057854A1/fr

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T8/00—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force
    • B60T8/17—Using electrical or electronic regulation means to control braking
    • B60T8/176—Brake regulation specially adapted to prevent excessive wheel slip during vehicle deceleration, e.g. ABS
    • B60T8/1764—Regulation during travel on surface with different coefficients of friction, e.g. between left and right sides, mu-split or between front and rear
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T8/00—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force
    • B60T8/32—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration
    • B60T8/34—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration having a fluid pressure regulator responsive to a speed condition
    • B60T8/50—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration having a fluid pressure regulator responsive to a speed condition having means for controlling the rate at which pressure is reapplied to or released from the brake
    • B60T8/505—Pressure reapplication in a mu-split situation, i.e. a situation with different coefficients of friction on both sides of the vehicle
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W10/00—Conjoint control of vehicle sub-units of different type or different function
    • B60W10/18—Conjoint control of vehicle sub-units of different type or different function including control of braking systems
    • B60W10/184—Conjoint control of vehicle sub-units of different type or different function including control of braking systems with wheel brakes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W10/00—Conjoint control of vehicle sub-units of different type or different function
    • B60W10/20—Conjoint control of vehicle sub-units of different type or different function including control of steering systems
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W30/00—Purposes of road vehicle drive control systems not related to the control of a particular sub-unit, e.g. of systems using conjoint control of vehicle sub-units
    • B60W30/02—Control of vehicle driving stability
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W40/00—Estimation or calculation of non-directly measurable driving parameters for road vehicle drive control systems not related to the control of a particular sub unit, e.g. by using mathematical models
    • B60W40/10—Estimation or calculation of non-directly measurable driving parameters for road vehicle drive control systems not related to the control of a particular sub unit, e.g. by using mathematical models related to vehicle motion
    • B60W40/114—Yaw movement
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D15/00—Steering not otherwise provided for
    • B62D15/02—Steering position indicators ; Steering position determination; Steering aids
    • B62D15/025—Active steering aids, e.g. helping the driver by actively influencing the steering system after environment evaluation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T2260/00—Interaction of vehicle brake system with other systems
    • B60T2260/02—Active Steering, Steer-by-Wire
    • B60T2260/024—Yawing moment compensation during mu-split braking
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W40/00—Estimation or calculation of non-directly measurable driving parameters for road vehicle drive control systems not related to the control of a particular sub unit, e.g. by using mathematical models
    • B60W40/12—Estimation or calculation of non-directly measurable driving parameters for road vehicle drive control systems not related to the control of a particular sub unit, e.g. by using mathematical models related to parameters of the vehicle itself, e.g. tyre models
    • B60W40/13—Load or weight
    • B60W2040/1307—Load distribution on each wheel suspension
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W2510/00—Input parameters relating to a particular sub-units
    • B60W2510/18—Braking system
    • B60W2510/182—Brake pressure, e.g. of fluid or between pad and disc
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W2520/00—Input parameters relating to overall vehicle dynamics
    • B60W2520/10—Longitudinal speed
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W2520/00—Input parameters relating to overall vehicle dynamics
    • B60W2520/26—Wheel slip
    • B60W2520/266—Slip values between left and right wheel
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W2530/00—Input parameters relating to vehicle conditions or values, not covered by groups B60W2510/00 or B60W2520/00
    • B60W2530/20—Tyre data
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W2552/00—Input parameters relating to infrastructure
    • B60W2552/40—Coefficient of friction
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W2710/00—Output or target parameters relating to a particular sub-units
    • B60W2710/18—Braking system
    • B60W2710/182—Brake pressure, e.g. of fluid or between pad and disc
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W2710/00—Output or target parameters relating to a particular sub-units
    • B60W2710/20—Steering systems
    • B60W2710/207—Steering angle of wheels

Definitions

  • the invention relates to a method for controlling a vehicle during a mue split braking according to the preamble of claim 1, as well as a control system and a vehicle.
  • the yawing movement of the vehicle when braking on a roadway with different friction coefficients can be increased by a geometry-dependent steering movement of the steerable vehicle axle, in particular the front axle, the steering movement occurring automatically due to the different braking forces on the sides and also oriented in the direction of high friction is.
  • the vehicle yaws with a mue-split braking with a certain mue-split yaw rate, which occurs due to the different braking forces or braking pressures from side to side and the resulting automatic steering movement.
  • the object of the invention is therefore to provide a method for controlling a vehicle, with which safety-critical situations during a mue-split braking can be avoided.
  • the task is also to specify a control system and a vehicle.
  • control a vehicle during a mue-split braking first to determine whether there is a mue-split braking when a braking specification is present in the vehicle, and then to determine a direction of high friction in which the vehicle as a result of the determined mue split braking and a brake pressure difference set thereupon yaw.
  • a steering angle requirement is given and set as soon as or immediately after a mue split braking has been determined, the steering angle requirement depending on the determined high-friction value direction being specified such that a mue split yaw rate which arises in the case of mue split braking as a result of braking forces differing from side to side and due to a braking pressure difference formed thereby between the brake pressures on the wheel brakes of a vehicle axle, is compensated for after a setting of the steering angle requirement on the steerable vehicle axle .
  • a mue split braking occurs within the scope of the invention if, as a result of a braking specification on a roadway with different coefficients of friction on each side, different braking forces act on the wheels of the vehicle and different braking pressures are set on the vehicle's wheel brakes. Due to a brake pressure difference formed thereby between the brake pressures on the wheel brakes of a vehicle axle, the vehicle yaws with a mue split yaw rate in a direction of high friction. Simultaneously pretends to be trained brake pressure difference also a steering angle of a steerable vehicle axle automatically in the direction of high friction when braking on this steerable vehicle axle to different coefficients of friction.
  • the brake pressure is preferably regulated by an ABS control system that monitors the locking of the wheels and intervenes in a regulating manner via ABS control valves in order to maintain or reduce the brake pressure on these wheels if there is a tendency to lock. Because of this, the brake pressure difference arises when braking on a roadway with friction values that differ from side to side, which leads to braking forces that differ from side to side and thus leads to yawing of the vehicle.
  • the ABS control system can, for example, select high control, individual control or modified individual control of the brake pressures.
  • the steering angle requirement on the steerable vehicle axle is specified and set as part of a steering control in such a way that an actual yaw rate presently approximates a predetermined target yaw rate, in particular until the actual one Yaw rate corresponds to the predetermined target yaw rate.
  • a steering angle requirement is advantageously specified by means of which the vehicle is kept in the lane, a corresponding steering angle requirement being output and set immediately when a mue split yaw rate and thus mue split braking occurs which the actual yaw rate is adjusted in the direction of the target yaw rate.
  • the adjustment can be done in the manner of a PI controller, so that fast but also jump-free automated steering takes place.
  • the target yaw rate is derived from an actual yaw rate that is present in the vehicle. before mue split braking was detected. Steering movements that exist before the mue split braking, for example cornering, can thus be adopted as a starting state in a simple manner, to which the mue split braking regulates.
  • ABS control it is preferably further provided that if there is mue split braking on the wheel brakes of the vehicle, different brake pressures are set page by page in such a way that the brake pressures on high-friction wheels of the vehicle are initially applied to the brake pressures on low-friction wheels of the vehicle are adapted to the same vehicle axle,
  • the pressure build-up gradient being adapted to a steering gradient in such a way that a mue-split yaw rate which is due to an increase in the brake pressures on the high-friction wheels with the pressure build-up gradient results, counteracted with a steering angle requirement that is then adapted with the steering gradient and this can preferably be compensated for.
  • a modified individual control (MIR) in combination with the automated steering intervention can thus be improved, since the modified individual control no longer assumes the driver's reaction time, on the basis of which the pressure build-up gradient is determined, but the reaction time of the automated steering system, which can intervene faster than the driver.
  • the braking distance can thus be shortened, since the braking pressure on the high-friction wheel can be increased again more quickly.
  • the high friction value direction is also made for the high friction value direction to be determined as a function of the brake pressure difference and / or the wheel speed difference.
  • the direction of the yaw movement of the vehicle can be detected in a simple manner as a result of the mue split braking and can also be advantageously predicted.
  • the brake pressure difference which is set by the ABS control system on the basis of the different coefficients of friction, can be immediately recognized in which direction of high friction the vehicle will begin to yaw if there is no steering intervention.
  • the ABS control system can be used to counteract the build-up of the brake pressure difference even before a mue-split yaw rate has built up due to the brake pressure difference. So you can react even faster.
  • the brake pressure difference is estimated from ABS control signals, the brake pressures controlled at the wheel brakes being adjusted individually on the side in the presence of mue-split braking via ABS control valves as a function of the ABS control signals in order to form the Brake pressure difference, and / or the wheel speed difference from the wheel speed sensors to the individual wheels determined and output wheel speeds is determined.
  • the brake pressure information and the wheel speed information can thus be accessed in a simple manner without using additional sensors.
  • the brake pressure information can be estimated from a pre-pressure given to the ABS control valves and activation times of the respective ABS control valves, via which the brake pressure is maintained or reduced.
  • the respective ABS control valve must intervene more frequently in order to prevent blocking than an ABS control valve on the side with the high coefficient of friction, resulting in the brake pressure and, moreover, in a brake pressure difference between the wheels of a vehicle axle can be closed.
  • the steering angle requirement is automatically implemented on an steerable front axle via an electrically controllable steering system.
  • the fast response times of an automated steering system can be used to control the vehicle with a mue split braking.
  • the steering angle requirement depending on a tire of the vehicle and / or a road surface and / or an axle load and / or a track width as well as a steering roll radius of the steerable vehicle axle and / or a vehicle speed is specified.
  • other criteria can be considered that have an effect on the braking behavior on a road surface with different coefficients of friction and which can therefore have an influence on the automated intervention in the steering.
  • the steering angle of the steerable vehicle axle is dependent on one steered via a steering wheel Steering torque can be set, a driver yaw rate acting on the vehicle as a result of the input steering torque,
  • the steered steering torque is permitted if the effective driver yaw rate counteracts the mue split yaw rate and is otherwise suppressed.
  • This means that manual steering intervention via the steering wheel can also be permitted insofar as these do not leave the lane or cause instabilities and counteract the mue split braking.
  • a control system for controlling a vehicle is also provided during a mue split braking, with which the method according to the invention can be carried out in particular, the control system having an electronically controllable braking system, the electronically controllable braking system being designed at a mue -Split braking as a result of a braking specification on a roadway with different friction values on the wheel brakes of the vehicle, different braking pressures on the sides, preferably with the aid of an ABS control system, and an electronically controllable steering system for setting a steering angle requirement on a steerable vehicle axle, the control system being designed
  • FIG. 1 shows a vehicle with an electronically controllable braking system and an electronically controllable steering system
  • FIG. 2 shows a flow diagram of the method according to the invention.
  • Fig. 1 shows schematically a vehicle 1 with an electronically controllable braking system 2 and an electronically controllable steering system 3, which together form a control system 100 for controlling a vehicle 1 during a mue split braking Bmu.
  • the electronically controllable brake system 2 has, in a known manner, a brake control device 2.1, which can control wheel brakes 4Ar, 4AI, 4Br, 4BI on the individual wheels 5Ar, 5AI, 5Br, 5BI of the vehicle axles 6A, 6B in a wheel-specific manner in order to manually control the vehicle 1 or an automated brake application BV.
  • the braking is monitored here by a stability control system 7, which evaluates the stability of the vehicle 1 and intervenes accordingly in order to avoid or counteract instability.
  • a component of the stability control system 7 is in particular an ABS control system 7.1, which monitors the slip value as a function of determined wheel speeds nAr, nAI, nBr, nBI of the individual wheels 5Ar, 5AI, 5Br, 5BI and if one or more wheels 5Ar is imminent blocking , 5AI, 5Br, 5BI which are controlled on the wheel brakes 4Ar, 4AI, 4Br, 4BI Brake pressure pAr, pAI, pBr, pBI individually adjusted via ABS control valves 8Ar, 8AI, 8Br, 8BI rad.
  • ABS control system 7.1 which monitors the slip value as a function of determined wheel speeds nAr, nAI, nBr, nBI of the individual wheels 5Ar, 5AI, 5Br, 5BI and if one or more wheels 5Ar is imminent blocking , 5AI, 5Br, 5BI which are controlled on the wheel brakes 4Ar, 4AI, 4Br, 4BI
  • the brake pressure pAr, pAI, pBr, pBI can be maintained or reduced, for example, in order to prevent the wheels 5Ar, 5AI, 5Br, 5BI from locking.
  • the ABS control valves 8Ar, 8AI, 8Br, 8BI have, for example, inlet valve-outlet valve combinations.
  • ABS control valves 8Ar, 8AI, 8Br, 8BI are e.g. controlled by the brake control device 2.1 in certain control cycles via an ABS control signal SAr, SAI, SBr, SBI to achieve pressure maintenance or pressure reduction on the respective wheel brake 4a, 4b.
  • the ABS control logic for the respective vehicle axles 6A, 6B can also be integrated in an electronically controllable axle module, which generates the corresponding ABS control signals SAr, SAI, SBr, SBI.
  • the electronically controllable steering system 3 via which a steering angle L of the wheels 5Ar, 5AI, 5Br, 5BI of a steerable vehicle axle 6A, 6B, preferably the front axle 6A or another additional axle, can be adjusted automatically via a steering actuator 9 .
  • a steering control device 3.1 is provided, which can specify steering signals SL for the steering actuator 9.
  • the steering angle L of the front wheels 5Ar, 5AI on the front axle 6A can also be adjusted manually by the driver via a steering wheel 10 by applying a specific steering torque LM in a steering direction LR.
  • the steering of the front axle 6A can e.g. by an overlay steering.
  • the ABS control system 7.1 uses different control cycles or different ABS control signals SAr, SAI on each side to ensure that different brake pressures pAr, pAI on the wheel brakes 4Ar, 4AI of the front wheels 5Ar, 5AI are controlled in order to block the front wheels 5Ar , 5AI on the roadway 11 with the friction coefficients ml, mr that differ individually on the sides.
  • the front wheel 5Ar, 5AI which is located on the side of the road 1 1 with the higher of the two coefficients of friction ml, mR, is hereinafter referred to as the high-friction front wheel 5HA and the front wheel 5Ar, 5AI, which is on the side of the road 11 with the lower of the two friction values ml, mR is referred to below as the low-friction front wheel 5NA.
  • a certain yaw of the vehicle 1 is effected with a mue-split yaw rate Gmu be, which is particularly dependent on a track width SW of the front axle 6A.
  • the mue split yaw rate Gmu is oriented in a high-friction direction Rh, ie the vehicle 1 yaws in the direction of the high-friction front wheel 5HA; 1 in the direction of travel to the left.
  • a steering movement with a specific steering angle L on the front axle 6A is also induced due to the differently set braking pressures pAr, pAI, when the front wheels 5Ar, 5AI are braked, the steering movement also reducing the friction Is directed towards Rh.
  • the steering angle L is dependent on the vehicle geometry, for example a steering roller radius (steering roller radius).
  • a brake pressure difference dp can at least be estimated, whereby it is to be expected that the low-friction front wheel 5HA will have a more frequent control and thus longer control times tAr, tAI of the respective ABS control valve 8Ar, 8AI will be present, since it is necessary to intervene more frequently on this low-friction front wheel 5HA in order to prevent blocking prevent than with the high friction front wheel 5NA.
  • the wheel speeds nAI, nAr or the wheel speed difference dn can be determined directly from wheel speed signals which are output by wheel speed sensors 12Ar, 12AI, 12Br, 12BI on the individual wheels 5Ar, 5AI, 5Br, 5BI.
  • a second step St2 after determining that a mue split braking Bmu is present, it is determined in which direction the mue split yaw rate Gmu is oriented or in which direction of high friction Rh the vehicle 1 is based on the Split braking Bmu will yaw. This follows, for example, from the sign of the wheel speed difference dn or the brake pressure difference dp, since a lower brake pressure pAr, pAI or a lower wheel speed nAr, nAI derived from the ABS control signals SAr, Sal can be expected for the high-friction front wheel 5HA is.
  • the brake pressure difference dp can thus already be used to predict in which direction of high friction RH the vehicle 1 will yaw.
  • a steering angle request LSoll is then generated in a third step St3 as part of a continuous steering control LG and, for example, via the steering control device 3.1 output in the steering signal SL to the steering actuator 9.
  • the steering angle requirement LSoll is determined in such a way that the required Split yaw rate Gmu is counteracted. That is, the steering angle request LSoll leads to a steering angle L on the front axle 6A, which compensates for the mue-split yaw rate Gmu.
  • a steering control LG in a first sub-step St3.1 e.g. an empirically determined start value WL for the steering angle request LSoll. Based on this, an actual yaw rate Glst of the vehicle 1 is then continuously monitored in a second sub-step St3.2 and compared with a target yaw rate GSoll in order to determine the reaction of the vehicle 1 to the steering angle request LSoll. As long as there is a discrepancy between the actual yaw rate Glst and the target yaw rate GSoll, the steering angle requirement LSoll will continue to be adjusted until the actual yaw rate Glst and the target yaw rate GSoll match within a tolerance.
  • the control can be carried out, for example, in the manner of a PI controller in order to obtain a fast but also “gentle” control without jumps.
  • the actual yaw rate Glst can in this case be provided, for example, by the stability control system 7, which determines this anyway for further stability controls, so that no further sensors are required.
  • the target yaw rate GSoll for this steering control LG can be set such that outside of a mue-split braking Bmu the actual yaw rate Glst of the vehicle 1 is continuously determined and stored, for example, in a storage device 13.
  • the value of the actual yaw rate Glst last saved before this determination is defined as the target yaw rate GSoll and is used as the basis for the steering control LG.
  • steering movements originally specified by the driver can also be taken into account if the vehicle 1 is in a mue split braking Bmu, for example, in a curve or when overtaking. If the vehicle 1 is driving straight ahead, a target yaw rate GSoll of approximately zero can be assumed.
  • the steering request LSoll is maintained in a fourth step St4, since the mue-split yaw rate Gmu is automatically compensated or compensated for by the active steering and the vehicle 1 in the the original trace continues. Leaving the lane or the lane and possibly following instabilities and thus endangering one's own vehicle 1 and the surrounding traffic can thus be efficiently avoided by this steering control LG.
  • the described automated steering control LG ensures that a steering intervention via the steering request LSoll takes place immediately when a mue-split braking Bmu is initiated and not only when the vehicle 1 has thereby left the lane and possibly already an instability has arisen.
  • the corrective steering intervention can be less, since the mue split yaw rate Gmu is counteracted right at the beginning when it arises, and not only when the vehicle 1 consequently leaves or breaks out of the lane. This significantly reduces the deviation from the original track.
  • the automated steering can also take place due to the electronic control with a shorter response time than with manual steering, so that the risk of safety-critical effects on one's own vehicle 1 and the surrounding traffic can be minimized.
  • a steering torque LM applied by the driver via the steering wheel 10 can be determined, for example, via a force sensor 14 which interacts with a torsion bar of the steering system 3.
  • Influencing the steering angle L as a function of this steering torque LM can then be permitted by the steering system 3 if a steering yaw rate GF acts on the vehicle 1 through the steering torque LM, which is opposed to the mue-split yaw rate and this, as well as the automated one Steering requirement LSoll compensated. If the driver specifies manual steering in a steering direction LR that corresponds to the steering direction LR of the steering actuator 9, this is permitted. However, if the driver steers in the opposite steering direction LR, ie the driver yaw rate GF increases the mue split yaw rate Gmu, implementation by the steering system 3 can be prevented in order to avoid risk of instability or lane departure.
  • a fourth sub-step St3.4 it can be provided that the ABS brake control is adjusted in the ABS control system 7.1, whereby a braking distance of the vehicle 1 can be shortened during such mue-split braking Bmu.
  • the ABS brake control can normally take place during a mue-split braking Bmu in accordance with a modified individual control (MIR).
  • MIR modified individual control
  • the brake pressure pAr, pAI on the high-friction front wheel 5HA is first reduced to the braking pressure pAR, pAI, which is set on the low-friction front wheel 5NA, so that a mue split Yaw rate Gmu is zero.
  • the brake pressure pAr, pAI on the high-friction front wheel 5HA is then slowly increased again with a pressure build-up gradient dpG to the slip threshold.
  • the pressure build-up gradient dpG is normally set in such a way that the driver has the opportunity to react to the resulting mue split yaw rate Gmu. Since in the steering control LG according to the steps St3, St3.1, St3.2, St3.3 an automated steering control LG takes place via the steering actuator 9, it can be assumed that a very quick and adequate reaction to a pressure increase at the high friction value Front wheel 5HA can be done as part of the MIR.
  • the pressure build-up gradient dpG can be increased accordingly, since the resulting rapidly increasing mue-split yaw rate Gmu via the steering actuator 9 can also react quickly with a coordinated steering gradient dLG.
  • the braking distance can be shortened compared to a normal MIR, since the braking pressure pAr, pAI on the high-friction front wheel 5HA can be raised again more quickly.
  • the vehicle 1 can be kept on track by the rapid and automated adjustment of the steering angle L with a correspondingly high steering gradient dLG, so that this results in a combinatorial effect compared to the prior art.
  • the steering angle requirement LSoll is determined as a function of further criteria, for example the axle load KL on the respective vehicle axle 6A, 6B, the selection of the tires KB used, a track width SW and a steering roll radius of the Front axle 6A, the vehicle speed v and a road surface condition KF of the road 1 1 can be used as criteria.
  • the method just described for controlling the vehicle 1 via the control system 100 can be carried out in the brake control device 2.1 of the brake system 2, in particular as part of the stability control system 7.
  • the stability control system 7 can be expanded accordingly on the software and / or hardware side.
  • the brake control device 2.1 already has a large part of the parameters used via a CAN bus in the vehicle 1 and also a connection fertilizer for an electric steering system 3 may already be present, so that only minor adjustments are necessary.
  • nAr nAI wheel speeds of the front wheels (right, left) nBr, nBI wheel speeds of the rear wheels (right, left) pAr, pAI brake pressure on the front wheels (right, left) pBr, pBI brake pressure on the rear wheels (right, left) Rh direction of high friction

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  • Engineering & Computer Science (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Physics & Mathematics (AREA)
  • Automation & Control Theory (AREA)
  • Fluid Mechanics (AREA)
  • Mathematical Physics (AREA)
  • Regulating Braking Force (AREA)

Abstract

L'invention concerne un procédé de commande d'un véhicule (1) pendant un freinage mu-split, une pression de freinage (p Ar, p Al, p Br, p Bl) différente de chaque côté étant ajustée sur les freins de roue (4Ar, 4Al, 4Br, 4Bl) du véhicule (1) lors d'un freinage mu-split consécutif à une consigne de freinage sur une chaussée (11) présentant des valeurs de frottement (mr, ml) différentes de chaque côté, en conséquence de quoi le véhicule (1) fait des lacets à un taux de lacet mu-split (Gmu) dans une direction (Rh) de valeur de frottement élevée en même temps qu'un angle de braquage (L) d'un essieu orientable (6A) du véhicule est décalé dans la direction (Rh) de valeur de frottement élevée. Le procédé selon l'invention comprend les étapes consistant - à constater l'existence d'un freinage mu-split en présence d'une consigne de freinage dans le véhicule (1) et à déterminer la direction (Rh) de valeur de frottement élevée dans laquelle le véhicule (1) fait des lacets en raison du freinage mu-split et de la différence de pression de freinage ajustée en conséquence, et - à prescrire et ajuster une spécification de l'angle de direction dès qu'un freinage mu-split est constaté, la spécification de l'angle de braquage étant prescrite en fonction de la direction (Rh) de valeur de frottement élevée de telle manière que le taux de lacet mu-split (Gmu) est compensé après ajustement de la spécification de l'angle de braquage au niveau de l'essieu (6A) orientable du véhicule.
PCT/EP2019/071436 2018-09-18 2019-08-09 Procédé de commande d'un véhicule pendant un freinage mu-split, système de commande et véhicule WO2020057854A1 (fr)

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DE102018122867.8 2018-09-18
DE102018122867.8A DE102018122867A1 (de) 2018-09-18 2018-09-18 Verfahren zum Steuern eines Fahrzeuges während einer mue-Split-Bremsung, Steuersystem und Fahrzeug

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DE102021202270A1 (de) 2021-03-09 2022-09-15 Robert Bosch Gesellschaft mit beschränkter Haftung Vorrichtung und Verfahren zum Betreiben eines Fahrzeugs

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EP1209053A1 (fr) * 2000-11-24 2002-05-29 Renault Procédé d'assistance d'un véhicule en freinage asymétrique
US20070188020A1 (en) * 2003-12-23 2007-08-16 Continental Teves Ag & Co. Ohg Method for controlling a brake pressure
US20130013152A1 (en) * 2010-03-24 2013-01-10 Falk Hecker Method for operating a brake device of a vehicle with a brake pressure difference on an axle adapted as a function of a steer input
DE102011120667A1 (de) 2011-12-09 2013-06-13 Wabco Gmbh Fahrstabilisierungsverfahren, Fahrstabbilisierungseinrichtung und Fahrzeug damit
DE102007038575B4 (de) 2007-08-16 2016-05-19 Wabco Gmbh Verfahren zum Einstellen eines Lenkwinkels einer elektronisch gelenkten Achse eines Nutzfahrzeuges

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DE50207264D1 (de) * 2001-09-14 2006-08-03 Bayerische Motoren Werke Ag Verfahren zum Kompensieren eines beim Bremsen auftretenden Giermoments
DE102005049368B4 (de) * 2005-10-11 2017-06-08 Volkswagen Ag Verfahren und Vorrichtung zum Abbremsen eines zweispurigen Kraftfahrzeugs bei unterschiedlichen Reibungsverhältnissen der Fahrzeugspuren
DE102006050215B4 (de) * 2005-11-22 2019-05-09 Continental Teves Ag & Co. Ohg Verfahren und Vorrichtung zum Stabilisieren eines Kraftfahrzeugs
DE102010028140A1 (de) * 2010-04-23 2013-03-21 Zf Lenksysteme Gmbh Fahrerassistenzverfahren für ein Kraftfahrzeug mit einer Spurführungsassistenzfunktion

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1209053A1 (fr) * 2000-11-24 2002-05-29 Renault Procédé d'assistance d'un véhicule en freinage asymétrique
US20070188020A1 (en) * 2003-12-23 2007-08-16 Continental Teves Ag & Co. Ohg Method for controlling a brake pressure
DE102007038575B4 (de) 2007-08-16 2016-05-19 Wabco Gmbh Verfahren zum Einstellen eines Lenkwinkels einer elektronisch gelenkten Achse eines Nutzfahrzeuges
US20130013152A1 (en) * 2010-03-24 2013-01-10 Falk Hecker Method for operating a brake device of a vehicle with a brake pressure difference on an axle adapted as a function of a steer input
DE102011120667A1 (de) 2011-12-09 2013-06-13 Wabco Gmbh Fahrstabilisierungsverfahren, Fahrstabbilisierungseinrichtung und Fahrzeug damit

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