EP0876272A1 - Method of improving the control characteristics of a brake pressure regulation system - Google Patents
Method of improving the control characteristics of a brake pressure regulation systemInfo
- Publication number
- EP0876272A1 EP0876272A1 EP97900977A EP97900977A EP0876272A1 EP 0876272 A1 EP0876272 A1 EP 0876272A1 EP 97900977 A EP97900977 A EP 97900977A EP 97900977 A EP97900977 A EP 97900977A EP 0876272 A1 EP0876272 A1 EP 0876272A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- vehicle
- acceleration
- brake pressure
- control
- difference signal
- Prior art date
- Legal status (The legal status 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 status listed.)
- Ceased
Links
- 238000000034 method Methods 0.000 title claims abstract description 17
- 230000001133 acceleration Effects 0.000 claims abstract description 44
- 238000004422 calculation algorithm Methods 0.000 claims abstract description 8
- 238000011156 evaluation Methods 0.000 abstract description 2
- RAPBNVDSDCTNRC-UHFFFAOYSA-N Chlorobenzilate Chemical compound C=1C=C(Cl)C=CC=1C(O)(C(=O)OCC)C1=CC=C(Cl)C=C1 RAPBNVDSDCTNRC-UHFFFAOYSA-N 0.000 abstract 1
- 230000006399 behavior Effects 0.000 description 4
- 238000011946 reduction process Methods 0.000 description 3
- 230000028838 turning behavior Effects 0.000 description 2
- 230000006978 adaptation Effects 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000009987 spinning Methods 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
- 238000012731 temporal analysis Methods 0.000 description 1
- 230000001960 triggered effect Effects 0.000 description 1
Classifications
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- 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
- B60T8/1755—Brake regulation specially adapted to control the stability of the vehicle, e.g. taking into account yaw rate or transverse acceleration in a curve
-
- 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
- B60T8/175—Brake regulation specially adapted to prevent excessive wheel spin during vehicle acceleration, e.g. for traction control
-
- 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
- B60T2210/00—Detection or estimation of road or environment conditions; Detection or estimation of road shapes
- B60T2210/10—Detection or estimation of road conditions
- B60T2210/14—Rough roads, bad roads, gravel roads
-
- 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
- B60T2210/00—Detection or estimation of road or environment conditions; Detection or estimation of road shapes
- B60T2210/10—Detection or estimation of road conditions
- B60T2210/16—Off-road driving conditions
Definitions
- the invention relates to a method for improving the control behavior of a
- Brake pressure control system for motor vehicles in which the rotational behavior of the individual vehicle wheels is detected with wheel sensors and in which, by logically linking and evaluating the sensor signals, a vehicle reference speed, which approximately reflects the vehicle speed, and a vehicle reference acceleration are formed, and brake pressure control signals according to a predetermined control mode are obtained and in which the body movement or the body acceleration is measured with one or more vehicle acceleration sensors.
- ABS Anti-lock braking systems
- ASR traction control systems
- FDR driving stability control systems
- ASMS driving stability control systems
- the brake pressure is regulated in such a way that the wheels rotate with slippage during full braking, in which both high braking forces and high lateral forces can be transmitted.
- the vehicle remains steerable when the brakes are applied fully.
- brake pressure control based on brake pressure control are also known.
- traction control an attempt is made to prevent the driven wheels from spinning when the vehicle is started by braking.
- driving stability control the vehicle should be prevented from skidding about its vertical axis by means of a targeted build-up of brake pressure.
- control methods developed in particular for an anti-lock braking system are based on the fact that an attempt is made from the signals from the wheel sensors, which record the turning behavior of the wheels, to keep the respective wheel speed in the range of the optimal use of the coefficient of friction.
- Vehicle-specific limit values are defined in the control algorithm, and when they occur, the brake pressure is adjusted.
- Wheel decelerations and / or slip values are defined so that the brake pressure can be reduced if the vehicle wheels decelerate too much or enter into excessive slip, ie they have a tendency to lock. In this way, the wheel slip can be kept in the area of optimal use of the coefficient of friction.
- the threshold values of the regulation are defined for firm, level road surfaces with a decreasing ⁇ slip curve depending on the coefficient of friction of the road.
- Limit values for the slip to be observed can also be defined in a similar manner, a control intervention taking place if the current slip is outside the defined limit values.
- intervention thresholds are adapted in the sense that higher slip values or acceleration thresholds are permitted or that no unjustified pressure reduction processes caused by vibrations are triggered.
- vehicle acceleration is intended to capture both positive and negative values of the speed change.
- the invention is based on the object of developing a method of the type mentioned at the outset which leads to an even better adaptation of the control to the respective driving situation or to the respective road conditions.
- the invention is based on the consideration that the value of the reference acceleration calculated on the basis of the wheel sensor signals represents a time-averaged value for the entire vehicle.
- An acceleration sensor which is connected to the vehicle body or to the vehicle chassis, measures the accelerations (vibrations) of these components.
- the acceleration of the entire vehicle can be represented by the calculated reference vehicle acceleration. If the difference between the values provided by the acceleration sensor and the calculated reference acceleration is formed, the movement (acceleration) of the body or chassis relative to the entire vehicle can be represented.
- event signals can be output based on which the control algorithm for brake pressure control is adapted.
- FIG. 1 The idea of the invention is illustrated with the aid of a very schematic illustration in FIG. 1.
- a vehicle acceleration sensor 10 is connected to the body 1 and reflects the acceleration or deceleration of the body 1 in the longitudinal direction of the vehicle. At this point it should be noted that the procedure is natural can be refined if the lateral acceleration of the vehicle is also detected.
- the wheel sensors 6, 7, 8, 9 reproduce an angle-resolved signal, the time derivative of which represents the angular speed of the wheels or, in short, the wheel speed.
- the vehicle acceleration (or deceleration) sensor 10 likewise delivers an acceleration signal, which, however, only reproduces the longitudinal acceleration a Kar (step 14) of the body 1.
- This acceleration signal is not identical to the vehicle reference acceleration because it is the acceleration of the entire vehicle and additionally shows the vibrations of the body caused by uneven road surfaces and is not averaged over time. If the two signals 13, 14 are compared in a difference generator 15, a relative deceleration is obtained which represents the deceleration or acceleration (vibrations) of the body in relation to the overall vehicle. When signals are referred to in this context, it is not meant individual values, but rather a representation of the respective magnitude over time.
- the relative signal 16 can now be analyzed with regard to its frequency and the occurring amplitudes. The following two criteria can be derived:
- the event signal El is output.
- the event signal E2 is output.
- ⁇ a (determined in block 16), further criteria can also be derived.
- the brake pressure control can now be adapted. The adjustment will go ahead everything consists in that the intervention thresholds are increased, so that higher slip values and / or deceleration values are allowed before the control system is started. It can also be provided that brake pressure reduction processes take place more slowly.
Landscapes
- Engineering & Computer Science (AREA)
- Transportation (AREA)
- Mechanical Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Regulating Braking Force (AREA)
- Hydraulic Control Valves For Brake Systems (AREA)
Abstract
A method is proposed for improving the control characteristics ofa brake pressure regulation system for vehicles and involves the following: the turning characteristics of the individual vehicle wheels are determined with wheel sensors, a vehicle reference speed (approximately equal to the vehicle speed) and vehicle reference acceleration are determined by logical connection and evaluation of the sensor signals, a brake pressure control signal is formed and brake pressure control signals are generated in accordance with a predetermined regulation mode, and vehicle acceleration sensors are used to determine vehicle body acceleration. The difference between the vehicle reference acceleration (aref; 13) and car body acceleration (aKar; 14) is determined and evaluated to ascertain the road conditions at a given moment. The regulation mode or algorithm is then varied in accordance with the difference signal (Δ; 16).
Description
Verfahren zur Verbesserung des Regelverhaltens eines BremsdruckregelungssystemsMethod for improving the control behavior of a brake pressure control system
Die Erfindung bezieht sich auf ein Verfahren zur Verbesserung des Regelverhaltens einesThe invention relates to a method for improving the control behavior of a
Bremsdruckregelungssystems für Kraftfahrzeuge, bei dem das Drehverhalten der einzelnen Fahrzeugräder mit Radsensoren erfaßt wird und bei dem durch logische Verknüpfung und Auswertung der Sensorsignale eine Fahrzeug- Referenzgeschwindigkeit, die näherungsweise die Fahrzeuggeschwindigkeit wiedergibt, und eine Fahrzeug- Referenzbeschleunigung gebildet und Bremsdruck-Steuersignale nach einem vorgegebenen Regelungsmodus gewonnen werden und bei dem mit einem oder mit mehreren Fahrzeug- Beschleunigungssensoren die Karosserie-Bewegung bzw. die Karosserie-Beschleunigung gemessen wird.Brake pressure control system for motor vehicles, in which the rotational behavior of the individual vehicle wheels is detected with wheel sensors and in which, by logically linking and evaluating the sensor signals, a vehicle reference speed, which approximately reflects the vehicle speed, and a vehicle reference acceleration are formed, and brake pressure control signals according to a predetermined control mode are obtained and in which the body movement or the body acceleration is measured with one or more vehicle acceleration sensors.
Zu den Bremsdruckregelungssystemen, für die das Verfahren verwendet wird, zählen u.a. Antiblockiersysteme (ABS), Antriebsschlupfregelungen (ASR) , Fahrstabilitätsregelungen (FDR, ASMS) etc..The brake pressure control systems for which the method is used include Anti-lock braking systems (ABS), traction control systems (ASR), driving stability control systems (FDR, ASMS) etc.
Bei einem Antiblockiersystem wird z.B. der Bremsdruck derart geregelt, daß sich die Räder bei einer Vollbremsung mit einem Schlupf drehen, bei dem sowohl hohe Bremskräfte als auch hohe Seitenkräfte übertragen werden können. Dies hat zur Folge, daß das Fahrzeug bei einer Vollbremsung lenkbar bleibt.
Es sind auch andere Kraftfahrzeug-Regelungssysteme in zahlreichen Varianten bekannt, die auf Bremsdruckregelung basieren. So wird z.B. bei einer Antriebsschlupfregelung versucht, durch Bremseneingriff ein Durchdrehen der angetriebenen Räder beim Anfahren zu verhindern. Bei einer Fahrstabilitätsregelung soll durch einen gezielten Bremsdruckaufbau an bestimmten Rädern ein Schleudern des Fahrzeuges um seine Hochachse verhindert werden.In an anti-lock braking system, for example, the brake pressure is regulated in such a way that the wheels rotate with slippage during full braking, in which both high braking forces and high lateral forces can be transmitted. As a result, the vehicle remains steerable when the brakes are applied fully. Numerous variants of other motor vehicle control systems based on brake pressure control are also known. For example, in the case of traction control, an attempt is made to prevent the driven wheels from spinning when the vehicle is started by braking. In the case of driving stability control, the vehicle should be prevented from skidding about its vertical axis by means of a targeted build-up of brake pressure.
Die insbesondere für ein Antiblockiersystem entwickelten Regelverfahren beruhen darauf, daß aus den Signalen der Radsensoren, die das Drehverhalten der Räder erfassen, mit einem Regelalgorithmus versucht wird, die jeweilige Radgeschwindigkeit im Bereich der optimalen Reibwertausnutzung zu halten.The control methods developed in particular for an anti-lock braking system are based on the fact that an attempt is made from the signals from the wheel sensors, which record the turning behavior of the wheels, to keep the respective wheel speed in the range of the optimal use of the coefficient of friction.
In dem Regelalgorithmus sind fahrzeugspezifische Grenzwerte definiert, bei deren Aufreten eine Anpassung des Bremsdruckes einsetzt.Vehicle-specific limit values are defined in the control algorithm, and when they occur, the brake pressure is adjusted.
So werden z.B. Radverzögerungen und/oder Schlupfwerte definiert, so daß der Bremsdruck abgebaut werden kann, wenn die Fahrzeugräder zu stark verzögern bzw. in zu hohen Schlupf einlaufen, also die Tendenz aufweisen zu blockieren. Auf diese Weise läßt sich der Radschlupf im Bereich der optimalen Reibwertausnutzung halten. Die Schwellenwerte der Regelung sind für feste, ebene Fahrbahnoberflächen mit abfallender μ-Schlupfkurve abhängig vom Reibwert der Fahrbahn definiert. In ähnlicher Weise lassen sich auch Grenzwerte für den einzuhaltenden Schlupf definieren, wobei ein Regeleingriff erfolgt, wenn sich der aktuelle Schlupf außerhalb der definierten Grenzwerte befindet.For example, Wheel decelerations and / or slip values are defined so that the brake pressure can be reduced if the vehicle wheels decelerate too much or enter into excessive slip, ie they have a tendency to lock. In this way, the wheel slip can be kept in the area of optimal use of the coefficient of friction. The threshold values of the regulation are defined for firm, level road surfaces with a decreasing μ slip curve depending on the coefficient of friction of the road. Limit values for the slip to be observed can also be defined in a similar manner, a control intervention taking place if the current slip is outside the defined limit values.
Bei Bremsungen auf welligen Fahrbahnoberflächen (Schlechtweg) oder Fahrbahnen mit losem Untergrund (off
road) ist es nicht angebracht, mit den Werten zu rechnen, die für feste, ebene Oberflächen definiert worden sind. Es kann als bekannt angesehen werden, daß auf den o.g. Untergründen die Bremswege verlängert werden, wenn mit den üblichen Grenz- bzw. Schwellenwerten gerechnet wird. Dies läßt sich darauf zurückführen, daß sich durch Schwingungen des Fahrwerks auf welligem Untergrund die Radlasten der einzelnen Räder sehr stark ändern ,was zu unerwünschten Bremsdruckabbau-Vorgängen führen kann. Auf losem Untergrund läßt sich die Verlängerung des Bremsweges dadurch erklären, daß dort die Kraftschlußausnutzung bei ansteigenden Schlupfwerten nicht wie sonst abfällt, sondern noch anwachsen kann; in der Abhängigkeit zwischen Kraftschlußausnutzung und Schlupf tritt kein Maximum auf. Dieses Verhalten wird durch die konventionellen Regelalgorithmen nicht oder nur in ungenügendem Maße abgedeckt.When braking on wavy road surfaces (rough road) or roads with loose surfaces (off road) it is not appropriate to use the values that have been defined for solid, flat surfaces. It can be considered known that the braking distances on the above-mentioned surfaces are extended if the usual limit or threshold values are used. This can be attributed to the fact that the wheel loads of the individual wheels change very strongly as a result of vibrations of the undercarriage on undulating ground, which can lead to undesirable brake pressure reduction processes. On loose ground, the lengthening of the braking distance can be explained by the fact that there the use of traction does not decrease as usual with increasing slip values, but can still increase; there is no maximum in the relationship between the use of adhesion and slip. This behavior is not or only insufficiently covered by the conventional control algorithms.
Für die genannten Fälle sind die normalen Regelalgorithmen, mit Eingriffsschwellen, die für feste, ebene Fahrbahnuntergründe definiert sind, zu empfindlich eingestellt. Es ist daher notwendig, o.g. Fahrwegbedingungen zu erkennen und geeignete Sonderregelmodi zu schalten, die insbesondere darin bestehen, daß Eingriffsschwellen in dem Sinne angepaßt werden, daß höhere Schlupfwerte oder Beschleunigungsschwellen erlaubt sind bzw. keine ungerechtfertigten, durch Schwingungen verursachte Druckabbau-Vorgänge ausgelöst werden.For the cases mentioned, the normal control algorithms with intervention thresholds that are defined for firm, level road surfaces are set too sensitive. It is therefore necessary to Recognize guideway conditions and switch suitable special control modes, which consist in particular in that intervention thresholds are adapted in the sense that higher slip values or acceleration thresholds are permitted or that no unjustified pressure reduction processes caused by vibrations are triggered.
Aus der US-PS 4969100 ist ein Verfahren zur Bestimmung einer Fahrzeug-Referenzgeschwindigkeit bekannt, die aus den Signalen, die von den Radsensoren geliefert werden, abgeleitet wird. Gleichzeitig ist ein Beschleunigungssensor vorgesehen, dessen Werte mit der Referenzgeschwindigkeit bzw. mit einer daraus abgeleiteten Referenz-
Fahrzeugbeschleunigung verglichen werden. Im Falle einer Abweichung wird das Verfahren zur Bestimmung der Referenzgeschwindigkeit geändert.From US-PS 4969100 a method for determining a vehicle reference speed is known, which is derived from the signals supplied by the wheel sensors. At the same time, an acceleration sensor is provided, the values of which are related to the reference speed or a reference Vehicle acceleration can be compared. In the event of a deviation, the procedure for determining the reference speed is changed.
Mit dem Begriff Fahrzeugbeschleunigung sollen sowohl positive als auch negative Werte der Geschwindigkeitsänderung erfaßt werden.The term vehicle acceleration is intended to capture both positive and negative values of the speed change.
Der Erfindung liegt nun die Aufgabe zugrunde, ein Verfahren der eingangs genannten Art zu entwickeln, das zu einer noch besseren Anpassung der Regelung an die jeweilige Fahrsituation bzw. an die jeweilige Fahrbahnbedingungen führt.The invention is based on the object of developing a method of the type mentioned at the outset which leads to an even better adaptation of the control to the respective driving situation or to the respective road conditions.
Es hat sich herausgestellt, daß diese Aufgabe durch das im Anspruch 1 beschiebene Verfahren gelöst wird, dessen Besonderheit darin besteht, daß die Differenz zwischen der Fahrzeug-Referenzbeschleunigung und der Karosseriebeschleunigung gebildet und zum Erkennen der momentanen Fahrwegbedingungen ausgewertet wird und daß der Regelungsmodus bzw. der Regelungsalgorithmus in Abhängigkeit von dem Differenzsignal, also von der Fahrwegerkennung, variiert wird.It has been found that this object is achieved by the method described in claim 1, the peculiarity of which is that the difference between the vehicle reference acceleration and the body acceleration is formed and evaluated to recognize the current route conditions and that the control mode or Control algorithm depending on the difference signal, that is, the route detection, is varied.
Einige besonders vorteilhafte Ausführungsarten des erfindungsgemäßen Verfahrens sind in den Unteransprüchen beschrieben.Some particularly advantageous embodiments of the method according to the invention are described in the subclaims.
Die Erfindung beruht auf der Überlegung, daß der auf Basis der Radsensorsignale errechnete Wert der Referenz- Beschleunigung ein zeitlich gemittelter Wert für das Gesamtfahrzeuges dargestellt. Ein Beschleunigungssensor, der mit der Fahrzeugkarosserie bzw. mit dem Fahrzeugchassis verbunden ist, mißt die Beschleunigungen (Schwingungen) dieser Komponenten. Die Beschleunigung des Gesamtfahrzeuges
kann durch die errechnete Referenz-Fahrzeugbeschleunigung dargestellt werden. Bildet man die Differenz zwischen den Werten, die der Beschleunigungssensor liefert und der errechneten Referenz-Beschleunigung, läßt sich die Bewegung (Beschleunigung) der Karosserie bzw. des Chassis gegenüber dem Gesamtfahrzeug darstellen.The invention is based on the consideration that the value of the reference acceleration calculated on the basis of the wheel sensor signals represents a time-averaged value for the entire vehicle. An acceleration sensor, which is connected to the vehicle body or to the vehicle chassis, measures the accelerations (vibrations) of these components. The acceleration of the entire vehicle can be represented by the calculated reference vehicle acceleration. If the difference between the values provided by the acceleration sensor and the calculated reference acceleration is formed, the movement (acceleration) of the body or chassis relative to the entire vehicle can be represented.
Diese Bewegung wird nun vor allem charakterisiert durch die Fahrwegbedingungen. Bei unebenen Fahrbahnen werden Karosserie-(Chassis)-Beschleunigungen derThis movement is now mainly characterized by the track conditions. When the road is uneven, body (chassis) accelerations become the
Gesamtfahrzeugbeschleunigung (bzw. -Verzögerung) überlagert, so daß durch eine zeitliche Analyse des Differenzsignals hinsichtlich seiner Frequenzen und Amplitude diese Situation erkannt werden kann. Insbesondere läßt sich beim Auftreten kleiner Frequenzen und kleinen Amplituden auf Schlechtweg schließen. Bei niedriger Frequenz und großen Amplituden kann auf ein stark unebenes Gelände mit im allgemein losem Untergrund (off-road) geschlossen werden.Overall vehicle acceleration (or deceleration) is superimposed so that this situation can be recognized by a temporal analysis of the difference signal with regard to its frequencies and amplitude. In particular, when the occurrence of small frequencies and small amplitudes is difficult. If the frequency is low and the amplitudes are large, it can be concluded that the terrain is very uneven and the terrain is generally loose (off-road).
Entsprechend von festgelegten Kriterien lassen sich damit Ereignissignale ausgeben, aufgrund derer der Regelalgorithmus zur Bremsdruckregelung angepaßt wird.In accordance with defined criteria, event signals can be output based on which the control algorithm for brake pressure control is adapted.
Die Verdeutlichung des Erfindungsgedankens erfolgt anhand einer sehr schematischen Darstellung in der Fig. 1.The idea of the invention is illustrated with the aid of a very schematic illustration in FIG. 1.
Mit 1 ist eine schematisch dargestellte Fahrzeugkarosserie angedeutet. Diese wird über vier Räder 2,3,4,5 über allgemein bekannte Radaufhängungen getragen. Das Drehverhalten eines jeden Rades kann mit Hilfe eines sogenannten Radsensors 6,7,8,9 erfaßt werden. Mit der Karosserie 1 ist ein Fahrzeug-Beschleunigungssensor 10 verbunden, der die Beschleunigung bzw. Verzögerung der Karosserie 1 in Fahrzeuglängsrichtung wiedergibt. An dieser Stelle sei angemerkt, daß das Verfahren natürlich
verfeinert werden kann, wenn auch Querbeschleunigungeri des Fahrzeuges erfaßt werden.1 schematically shows a vehicle body. This is carried over four wheels 2, 3, 4, 5 over generally known wheel suspensions. The turning behavior of each wheel can be detected with the help of a so-called wheel sensor 6,7,8,9. A vehicle acceleration sensor 10 is connected to the body 1 and reflects the acceleration or deceleration of the body 1 in the longitudinal direction of the vehicle. At this point it should be noted that the procedure is natural can be refined if the lateral acceleration of the vehicle is also detected.
Die Radsensoren 6,7,8,9 geben ein winkelaufgelöstes Signal wieder, deren zeitliche Ableitung die Winkelgeschwindigkeit der Räder oder, kurz gesprochen, die Radgeschwindigkeit darstellt.The wheel sensors 6, 7, 8, 9 reproduce an angle-resolved signal, the time derivative of which represents the angular speed of the wheels or, in short, the wheel speed.
Durch logische Verknüpfung dieser Signale wird in der Schaltung 12 eine sogenannte Fahrzeug- Referenzgeschwindigkeit vref ermittelt, aus der wiederum inBy logically combining these signals, a so-called vehicle reference speed v ref is determined in the circuit 12, from which in turn in
13 die Fahrzeug-Referenzbeschleunigung aref abgeleitet wird.13 the vehicle reference acceleration a ref is derived.
In einer elektronischen Auswerteinheit 11 sind entsprechende Berechnungsalgorithmen implementiert.Corresponding calculation algorithms are implemented in an electronic evaluation unit 11.
Es sind unterschiedliche Methoden zur Errechnung dieser Referenzgrößen auf Basis der Radsensorsignale bekannt, die an dieser Stelle aber nicht näher erläutert zu werden brauchen, da sie dem Fachmann für eine Bremsdruckregelung geläufig sind. Es kommt auch nicht entscheidend auf die Art der Berechnung dies in 13 die Referenz- Fahrzeugbeschleunigung arefer Referenzggrößen an, vielmehr ist es notwendig zu wissen, daß die Referenzgeschwindigkeit die Geschwindigkeit des Gesamtfahrzeuges in einem zeitlichen Mittel wiedergibt. Die Referenzbeschleunigung stellt natürlich ebenso einen zeilichen Mittelwert dar.Different methods for calculating these reference variables on the basis of the wheel sensor signals are known, but need not be explained in more detail here, since they are familiar to a person skilled in the art for brake pressure control. It is also not critical to the type of calculation in FIG. 13 the reference vehicle acceleration as a reference variable, rather it is necessary to know that the reference speed reflects the speed of the entire vehicle in a time average. The reference acceleration is of course also a linear mean.
Der Fahrzeug-Beschleunigungs(bzw.-Verzögerungs)sensor 10 liefert ebenfalls ein Beschleunigungssignal, das allerdings nur die Längsbeschleunigung aKar (Stufe 14) der Karosserie 1 wiedergibt.The vehicle acceleration (or deceleration) sensor 10 likewise delivers an acceleration signal, which, however, only reproduces the longitudinal acceleration a Kar (step 14) of the body 1.
Dieses Beschleunigungssignal ist nicht identisch mit der Fahrzeug-Referenzbeschleunigung, da es die Beschleunigung
des gesamten Fahrzeuges und zusätzlich die durch Fahrbahnunebenheiten hervorgerufenen Schwingungen der Karosserie aufzeigt und keine zeitliche Mittelung erfährt. Setzt man die beiden Signale 13,14 in einem Differenzbildner 15 in Vergleich, so erhält man eine Relativverzögerung, die die Verzögerung bzw. Beschleunigung (Schwingungen) der Karosserie gegenüber dem Gesamtfahrzeug wiedergibt. Wenn in diesem Zusammenhang von Signalen gesprochen wird, so sind hier nicht Einzelwerte gemeint, sondern eine Darstellung der jeweiligen Größe im zeitlichen Verlauf.This acceleration signal is not identical to the vehicle reference acceleration because it is the acceleration of the entire vehicle and additionally shows the vibrations of the body caused by uneven road surfaces and is not averaged over time. If the two signals 13, 14 are compared in a difference generator 15, a relative deceleration is obtained which represents the deceleration or acceleration (vibrations) of the body in relation to the overall vehicle. When signals are referred to in this context, it is not meant individual values, but rather a representation of the respective magnitude over time.
Das Relativsignal 16 läßt sich nun hinsichtlich seiner Frequenz und den auftretenden Amplituden analysieren. Die zwei folgenden Kriterien lassen sich ableiten:The relative signal 16 can now be analyzed with regard to its frequency and the occurring amplitudes. The following two criteria can be derived:
Liegt ein erheblicher Hochfrequenzanteil mit entsprechender Amplitude vor, so läßt sich daraus schließen, daß das Fahrzeug auf unebenen Untergrund bewegt wird. Es wird das Ereignissignal El ausgegeben.If there is a significant high-frequency component with a corresponding amplitude, it can be concluded that the vehicle is being moved on an uneven surface. The event signal El is output.
Stellt man fest, daß niedrige Frequenzen dominieren, so läßt dies kontinuierlich geänderte Fahrbahnneigungen vermuten, woraus geschlossen werden kann, daß das Fahrzeug im off- road-Bereich bewegt wird. Es wird das Ereignissignal E2 ausgegeben.If one finds that low frequencies dominate, this suggests continuously changing road inclinations, from which it can be concluded that the vehicle is being moved in the off-road area. The event signal E2 is output.
Je nachdem, wie weit die Erkenntnis über die Darstellung von bestimmten Fahrwegsituationen in Signalen der Fahrzeug- Referenzbeschleunigung arβf (13), derDepending on how far the knowledge about the representation of certain route situations in signals of the vehicle reference acceleration a rβf (13), the
Karosseriebeschleunigung aKar (14) sowie im DifferenzsignalBody acceleration a Kar (14) and in the difference signal
Δa (ermittelt in dem Block 16) voranschreitet, lassen sich auch weitere Kriterien ableiten. Je nachdem, welches Ereigniskriterium El oder E2 vorliegt, kann nun die Bremsdruckregelung angepaßt werden. Die Anpassung wird vor
allem darin bestehen, daß die Eingriffsschwellen erhöht werden, so daß auch höhere Schlupfwerte und/oder Verzögerungswerte vor dem Einsetzen der Regelung erlaubt sind. Außerdem kann vorgesehen werden, daß Bremsdruckabbau- Vorgänge verlangsamt ablaufen.
Δa (determined in block 16), further criteria can also be derived. Depending on which event criterion El or E2 is present, the brake pressure control can now be adapted. The adjustment will go ahead everything consists in that the intervention thresholds are increased, so that higher slip values and / or deceleration values are allowed before the control system is started. It can also be provided that brake pressure reduction processes take place more slowly.
Claims
1. Verfahren zur Verbesserung des Regelverhaltens eines Bremsdruckregelungssystems für Kraftfahrzeuge, bei dem das Drehverhalten der einzelnen Fahrzeugräder mit Radsensoren erfaßt wird und bei dem durch logische Verknüpfung und Auswertung der Sensorsignale eine Fahrzeug-Referenzgeschwindigkeit, die näherungsweise die Fahrzeuggeschwindigkeit wiedergibt, und eine Fahrzeug- Referenzbeschleunigung gebildet und Bremsdruck- Steuersignale nach einem vorgegebenen Regelungsmodus gewonnen werden und bei dem mit einem oder mit mehreren Fahrzeug-Beschleunigungssensoren die Karosserie-Bewegung bzw. die Karosserie-Beschleunigung gemessen wird, dadurch gekennzeichnet, daß die Differenz zwischen der Fahrzeug-Referenzbeschleunigung (aref; 13) und der1. A method for improving the control behavior of a brake pressure control system for motor vehicles, in which the rotational behavior of the individual vehicle wheels is detected with wheel sensors and in which a vehicle reference speed, which approximately reflects the vehicle speed, and a vehicle reference acceleration are formed by logically linking and evaluating the sensor signals and brake pressure control signals are obtained in accordance with a predetermined control mode and in which the body movement or the body acceleration is measured with one or more vehicle acceleration sensors, characterized in that the difference between the vehicle reference acceleration (a ref ; 13 ) and the
Karosseriebeschleunigung (aKar; 14) gebildet und zumBody acceleration (a Kar ; 14) formed and to
Erkennen der momentanen Fahrwegbedingungen ausgewertet wird und daß der Regelungsmodus bzw. der Regelungsalgorithmus in Abhängigkeit von dem Differenzsignal (Δa; 16) variiert wird.Recognizing the current route conditions is evaluated and that the control mode or the control algorithm is varied depending on the difference signal (Δa; 16).
2. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß zum Variieren des Regelungsmodus die Regelungseintritts- Kriterien und -Schwellen geändert werden.2. The method according to claim 1, characterized in that the control entry criteria and thresholds are changed to vary the control mode.
3. Verfahren nach Anspruch 2, dadurch gekennzeichnet, daß das Differenzsignal (Δa; 16)) hinsichtlich der auftretenden Frequenzen analysiert wird, wobei bei einem großen Anteil von hohen Frequenzen die Regelungseintrittsschwellen so eingestellt werden, daß sie den Bedingungen auf unebener Fahrbahn angepaßt sind.3. The method according to claim 2, characterized in that the difference signal (Δa; 16)) is analyzed with regard to the frequencies which occur, the control entry thresholds being set so that they are adapted to the conditions on uneven road surfaces at a large proportion of high frequencies.
4. Verfahren nach Ansprüche 2 oder 3, dadurch gekennzeichnet, daß das Differenzsignal (Δa; 16) hinsichtlich seiner Frequenz analysiert wird und bei einem hohen Anteil von niedrigen Frequenzen die Regelungseintrittsschwellen so eingestellt werden, daß sie den Bedingungen für losen Untergrund angepaßt sind. 4. The method according to claims 2 or 3, characterized characterized in that the difference signal (Δa; 16) is analyzed with regard to its frequency and, in the case of a high proportion of low frequencies, the control entry thresholds are set such that they are adapted to the conditions for loose ground.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE1996102170 DE19602170A1 (en) | 1996-01-23 | 1996-01-23 | Procedure for determining route conditions |
| DE19602170 | 1996-01-23 | ||
| PCT/EP1997/000066 WO1997027092A1 (en) | 1996-01-23 | 1997-01-09 | Method of improving the control characteristics of a brake pressure regulation system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| EP0876272A1 true EP0876272A1 (en) | 1998-11-11 |
Family
ID=7783363
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP97900977A Ceased EP0876272A1 (en) | 1996-01-23 | 1997-01-09 | Method of improving the control characteristics of a brake pressure regulation system |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0876272A1 (en) |
| JP (1) | JP2000503277A (en) |
| DE (1) | DE19602170A1 (en) |
| WO (1) | WO1997027092A1 (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2392257B (en) * | 1999-10-12 | 2004-04-21 | Bosch Gmbh Robert | Device and process for regulating at least one vehicle movement quantity |
| DE19949286B4 (en) * | 1999-10-12 | 2013-09-26 | Robert Bosch Gmbh | Device and method for controlling at least one vehicle movement variable |
| JP4331881B2 (en) * | 2000-10-16 | 2009-09-16 | トヨタ自動車株式会社 | Road surface condition estimation device |
| CN102143869B (en) | 2008-11-25 | 2014-07-16 | 丰田自动车株式会社 | Vehicle travel control device |
| DE102012200653A1 (en) | 2011-01-19 | 2012-07-19 | Continental Teves Ag & Co. Ohg | Method for determining reference speed of vehicle e.g. motor car, involves comparing gradients of vehicle deceleration degree and model signal degree to determine vehicle reference speed |
| DE102013016087A1 (en) * | 2013-09-27 | 2015-04-02 | Wabco Gmbh | Method and system for controlling an electronic brake system |
| DE102015000216A1 (en) | 2014-03-11 | 2015-09-17 | Wabco Gmbh | Method for controlling electric motors in serial hybrid vehicles or fully electric vehicles with at least two separately driven axles |
Family Cites Families (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60596A (en) * | 1983-06-16 | 1985-01-05 | 株式会社デンソー | Road surface state identifier |
| DE3345729A1 (en) * | 1983-12-17 | 1985-06-27 | Alfred Teves Gmbh, 6000 Frankfurt | METHOD AND CIRCUIT ARRANGEMENT FOR SUPPRESSING UNWANTED CONTROL PROCESSES IN SLIP-CONTROLLED BRAKE SYSTEMS |
| US4774667A (en) * | 1985-04-04 | 1988-09-27 | Nippondenso Co., Ltd. | Brake control system for vehicle |
| JP2544911B2 (en) * | 1986-05-09 | 1996-10-16 | 曙ブレーキ工業株式会社 | Anti-skid control method |
| DE3709483A1 (en) * | 1987-03-23 | 1988-10-06 | Bosch Gmbh Robert | ANTI-BLOCKING CONTROL SYSTEM |
| JP2590169B2 (en) * | 1987-12-29 | 1997-03-12 | 住友電気工業株式会社 | Vehicle reference wheel speed calculator |
| DE3819424A1 (en) * | 1988-06-07 | 1989-12-14 | Lucas Ind Plc | METHOD FOR REGULATING THE BRAKE PRESSURE IN A BLOCK-PROTECTED VEHICLE BRAKE SYSTEM |
| JPH03246157A (en) * | 1990-02-23 | 1991-11-01 | Toyota Motor Corp | Antiskid controlling device |
| JPH03292247A (en) * | 1990-04-10 | 1991-12-24 | Mazda Motor Corp | Brake control device for vehicle |
| JP2616302B2 (en) * | 1991-09-25 | 1997-06-04 | 三菱電機株式会社 | Anti-skid control device |
| DE4336080A1 (en) * | 1993-10-22 | 1995-04-27 | Bosch Gmbh Robert | Anti-lock control system |
| JPH07205789A (en) * | 1994-01-26 | 1995-08-08 | Honda Motor Co Ltd | Antilock brake control method for four-wheel drive vehicle |
| JP3605421B2 (en) * | 1994-01-26 | 2004-12-22 | 本田技研工業株式会社 | Estimated vehicle speed calculation method |
-
1996
- 1996-01-23 DE DE1996102170 patent/DE19602170A1/en not_active Withdrawn
-
1997
- 1997-01-09 JP JP9526475A patent/JP2000503277A/en active Pending
- 1997-01-09 EP EP97900977A patent/EP0876272A1/en not_active Ceased
- 1997-01-09 WO PCT/EP1997/000066 patent/WO1997027092A1/en not_active Application Discontinuation
Non-Patent Citations (1)
| Title |
|---|
| See references of WO9727092A1 * |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2000503277A (en) | 2000-03-21 |
| WO1997027092A1 (en) | 1997-07-31 |
| DE19602170A1 (en) | 1997-07-24 |
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