DE102008021523A1 - Electronically controlled regulating system regulating method for e.g. motorcycle, involves carrying out brake pressure regulation in accordance with braking force distribution, and/or engine moment regulation and/or wheel lift recognition - Google Patents

Abstract

The method involves determining an angle (p ') between a steering rod (8) and a front wheel cross beam (9). A transverse dynamic size (ay) is determined by a sensor, which is arranged at the cross beam. A brake pressure regulation is carried out in accordance with a braking force distribution, and/or an engine moment regulation and/or a wheel lift recognition and/or driving dynamics regulation in dependence of the angle and/or the transverse dynamic size. The steering rod is aligned parallel to an inclination (p) of a quasi-single track vehicle (300). An independent claim is also included for an electronic regulation system comprising an angle determination unit.

Description

The The invention relates to a method according to the preamble of claim 1 and a control system according to the preamble of claim 15.

The motorcycle has evolved over the past few decades from a cost-effective means of transportation to a recreational vehicle, in which increasingly both the safety and the comfort of the driver is brought to the fore. Similar to automobiles some years ago, motorcycles are increasingly equipped with anti-lock braking systems (ABS). From the EP 0 548 985 B1 For example, a stall protection device for a two-wheeled motorcycle is known. Furthermore, from the DE 40 00 212 A1 a method for anti-lock braking of a two-wheel motorcycle known.

Traditionally, motorcycles each have one actuator for each of the two brake circuits. Most of the front brake is operated by a "hand brake lever" and the rear brake by a "foot brake lever". In the context of motorcycles, an "integral brake system" is understood to mean a brake system in which the brake of the other brake circuit is additionally braked when the handbrake lever or the footbrake lever is actuated by an active pressure buildup and / or foot brake lever), the automatic brake force distribution or brake pressure distribution between the front wheel and the rear wheel takes place, for example, via an electronic system by means of which a predetermined brake force distribution is controlled (also called ABD function (Active Brakeforce Distribution).) Integral brake systems for motorcycles are, for example of the DE 38 03 563 A1 and DE 103 16 351 A1 known.

In the DE 10 2005 003 255 A1 discloses a braking system for motorcycles, which ensures the functionality of ABS and integral brake in a structurally simple structure.

Out The prior art vehicles are known due to their kinematic degrees of freedom and dynamic properties as Single-track vehicles apply, but not over two but have three wheels, namely two (z. Narrow) front wheels and a (eg wider) rear wheel. These vehicles are referred to below as quasi-single-track vehicles. A special feature of these vehicles is that they - like conventional two-wheeled motorcycles or scooters - need an inclination, To build lateral accelerations, so go through even curves to be able to.

Quasi-single-track vehicles can be an interesting alternative for the future represent to the previous "real" single-track vehicles. One advantage of the tricycles is that with the help of two Narrow front wheels a better average grip is achieved in curves. In addition, the familiar from real Einspurfahrzeugen occurs Erecting force when cornering, which often to unwanted Steering actions and instabilities leads, in the Quasi-single-track vehicles only reduced or, depending on the design, not at all. At driving speed zero can be a three-wheeled Quasi-one-track vehicle without a conventional stand device be ascertained so that the driver is not his remote Feet must help. This property allows If necessary, an at least largely closed, weather-protected Body. Mobility, maneuverability and driving dynamics are still as good as the real one-track vehicle and by the kinematics of the front suspension only slightly limited.

A three-wheeled vehicle with two front steering wheels and a rear wheel is z. B. in the DE 601 10 308 T2 disclosed.

Of the Invention is based on the object, a method for improved Control of an electronically controlled control system and a improved electronic control system for motorcycles or to provide scooters with two front wheels.

These The object is achieved by the method according to claim 1 and the control system according to claim 15 solved.

Under The term "brake pressure control" is in addition to the invention the regulations of a brake pressure in the context of z. B. anti-lock systems (ABS) or traction systems (TCS or BTCS) also have a brake pressure regulation / specification according to a braking force distribution understood as they z. B. at an acive pressure buildup at an integral brake function occurs (ABD). Likewise, the term includes a brake pressure control in the context of a vehicle dynamics control system.

Under The term "traction control" is inventively a Brake pressure control and / or engine torque control understood.

Of the The invention is based on the idea of the transverse dynamics of the quasi single-track vehicle based on the angle between the handlebar and front cross member and / or based on the transverse dynamics of a sensor, which is arranged on the front wheel cross member, to determine and the particular lateral dynamics in at least one control method / system and / or recognition method / system.

The Invention is preferred in connection with anti-skid control (ABS), traction control (TCS), braking force distribution control of a Integral braking system (ABD function) and / or vehicle dynamics control used. These arrangements are made using the specific lateral dynamics better matched to the appropriate driving situation, what the driving safety elevated.

The The invention preferably relates to a brake control system for a quasi-Einspurfahrzeug or a method for controlling a electronically controlled braking system of a quasi-single-track vehicle.

Prefers is a cornering or cornering recognized by the fact that the certain skew angle or the angle between handlebar and front cross member or the lateral dynamics size exceeds a first predetermined threshold or for a given minimum period of time a first predetermined Exceeds threshold. So can the sensitivity of the Curve detection can be specified.

A critical cornering or corner braking is preferred then recognized if the particular skew angle or the angle between Handlebar and front cross member or the transverse dynamics size one exceeds the second predetermined threshold or for a predetermined minimum period of time exceeds a second predetermined threshold value. In order to take into account external influences, the second threshold is particularly preferably dependent of recognized road conditions and / or weather conditions (eg depending on a coefficient of friction).

A Braking is preferably detected on the basis of the driver's activated brake application form.

According to one preferred embodiment is from a predetermined Threshold for the oblique angle an increase in pressure on the front wheels during anti-skid control performed with a gradient (slope), which is lower is considered the gradient when driving straight ahead. Particularly preferred is the Limitation of the pressure build-up gradient when cornering only performed if the vehicle speed as well has crossed a threshold. It is very special preferred that the maximum allowable Druckaufbaugradient the lower is, the higher the current driving speed and / or the higher the angle of inclination reached.

alternative or in addition, it is preferable to the slip thresholds to detect an unstable Raddrehverhaltens or for activation an anti-skid control (brake pressure reduction) depending the skew angle and / or the vehicle speed pretend. The slip threshold is particularly preferred the more chosen smaller, the greater the skew angle is to turn early when the cornering To achieve anti-lock control.

According to one preferred embodiment of the invention Method and the control system according to the invention is the brake control (ABS and / or TCS and / or BTCS and / or ABD control), z. B. the maximum allowable pressure increase gradient or a slip threshold, and / or the engine torque control (TCS control) not only in dependence the basis of the angle between the handlebar and front cross member and / or the transverse dynamics measure Transverse dynamics or the basis of the angle between the handlebar and Front cross member and / or the transverse dynamics measure size certain skew angle, but in addition also depending on a specific or estimated Frictional coefficient and / or the particular road surface unevenness performed. Particularly preferred is the pressure increase gradient and / or the slip threshold the lower the estimated value or certain road friction coefficient. So is an early and achieved careful brake pressure control.

One Advantage of the invention is that through the improved control strategy the stability reserve of lateral force is improved so that a sideways slipping of a wheel at fast cornering and is less likely to corner braking. This increases driving safety and helps accidents and falls to avoid.

Further preferred embodiments of the invention will become apparent from the dependent claims and the description below based on figures.

It demonstrate

1 a schematic representation of a tricycle from the front in different driving situations,

2 a comparison of a tricycle vehicle with a two-wheeled vehicle,

3 a tricycle in various extreme driving situations,

4 an exemplary characteristic field for determining a maximum pressure increase gradient,

5 exemplary courses of brake pressures and speeds when limiting a pressure increase gradient,

6 an exemplary characteristic field for determining wheel slip thresholds for detecting a wheel instability,

7 schematic representations to illustrate the behavior of the two front wheels of a tricycle vehicle,

8th exemplary courses of brake pressures and speeds on the two front wheels of a tricycle vehicle in the event that different brake pressures are used on the two wheels (modified select-low strategy),

9 exemplary courses of the two front wheel speeds of a tricycle when lifting a front wheel in extreme cornering,

10 an exemplary characteristic field for determining an actively to be established brake pressure for an ABD function, and

11 a schematic block diagram for the integration of example functions in a standard control system.

The The invention does not relate to the mechanical construction of tricycles, which are already known from publications, but deals z. B. with the detection of cornering and the modifications of control strategies based thereon, e.g. ABS (Anti-lock Braking System) and TCS (Traction Control System, Traction Control System). Furthermore, control strategies are shown which represent an active driving stabilization of the vehicle in curves (Vehicle dynamics control).

1a ) shows schematically and greatly simplified an exemplary Quasi-Einspurfahrzeug in front view on a horizontal surface 11 , Quasi-wheeler 300 includes two front wheels 1 . 2 each with a front suspension 3 . 4 which about swivels 5 . 6 with cross member 9 are connected. On cross member 9 there is another hinge 7 , with the handlebar 8th connected is. To handlebar 8th is the handlebar 10 rigidly attached. The rear wheel, which is in this front view between the two front wheels 1 . 2 should be located, is not shown for reasons of clarity. In this schematic, highly simplified illustration is important that handlebar 8th with the vertical parts of the wheel suspensions 3 . 4 is guided by means not specified here so that they always run parallel to each other. The crossbeam 9 thus always runs parallel to the ground. This is also out 1b ), c) and e). To vehicle 300 is a suitable means for determining the angle ρ 'between the handlebar 8th and crossbeams 9 (and / or its amendment).

In 1b ) is the exemplary quasi-single-track vehicle 300 shown in front view schematically when cornering with a lateral acceleration a _y . To compensate for the centrifugal acceleration, the driver must drive the vehicle 300 in an inclined position with the angle ρ to the flat ground 11 bring. The axis 13 the steering column 8th thus moves by the angle ρ from the vertical axis 12 (perpendicular to the ground 11 ), where the tangent of the angle ρ is the ratio of the lateral acceleration a _y to the acceleration due to gravity according to: tan (ρ) = a y / 1 g (1) where 1 g is the gravitational acceleration acting on the vehicle (1 g = 9.81 m / s ² ).

As in 1b ), the components shift 3 . 4 and 8th although vertically against each other (be referred to the vertical axis 12 ), But held by the mentioned parallel guide to each other in the desired position, so that vehicle 300 the lateral acceleration a _{y can} stably support. Through the pivot points 5 . 6 and 7 remains cross member 9 in horizontal position or parallel to the footprint 11 , By way of example, the skew ρ is determined by changing the angle between the handlebar 8th and crossbeams 9 or the angle ρ 'between handlebar 8th and crossbeams 9 is measured. Inclination angle ρ and angle ρ 'depend on the relationship: ρ = 90 ° - ρ '(2) from each other.

The Measurement of the angle ρ 'is z. B. for a simple, per se known from the prior art Potentiometerprinzip possible, with which z. As an angle or a distance can be measured between two moving parts.

The lateral acceleration a _{y of} the vehicle 300 can then from the measured angle ρ 'according to the following equation: a y = 1 g · tan (ρ) = 1 g · tan (90 ° - ρ ') (3) be determined. This applies to the case of flat ground 11 ,

In 1c ) is the exemplary quasi-single-track vehicle 300 shown in front view schematically when cornering with a lateral acceleration a _y , where vehicle 300 in contrast to 1b ) on a sloped surface 16 with the inclination angle ρ1 moves. The (relative) inclination of the vehicle 300 is by the inclination angle ρ between the vehicle vertical axis 15 (parallel to handlebar 8th ) and the road 16 vertical axis 14 given. Between handlebar 8th and crossbeams 9 is the angle ρ 'on. Angle of inclination ρ and angle ρ 'are still related by equation (2), since the cross member 9 due to the construction parallel to the ground 16 is aligned.

An inclined ground 16 Usually occurs in very tight bends in mountainous terrain, as well as on race and test tracks and serves to support cornering. Vehicles should be better stabilized by compensating part of the centrifugal force by the downward slope.

By measuring the angle ρ 'between the handlebar 8th and crossbeams 9 Now only that portion of the lateral acceleration is detected, which is actually also transverse dynamics, so by lateral forces on the wheels to apply. This is because the inclination angle ρ between the vehicle vertical axis 15 and the roadway 16 vertical axis 14 now reduced exactly by the roadway inclination angle ρ1 (compared to a ride in the plane). According to 1d ) Therefore, only the smaller lateral acceleration a _{y_diff} must be _charged dynamic driving, which is _done via the detection of the angle ρ '(and thus ρ according to equation (2)) also completely independent of the respective roadway inclination. The relevant lateral acceleration a _{y_diff} is thus determined according to equation (3): a y_diff = 1 g · tan (ρ) = 1 g · tan (90 ° - ρ ') (4)

In 1e ) the case of a neutral cornering is shown, in which the slope ρ1 of the road 18 is exactly that big on the vehicle 300 acting lateral acceleration a _{y is} completely realized by the downgrade. In this special case, the vehicle takes no inclined position ρ relative to the sloping road surface 18 on (ρ = 0 °), ie the vehicle vertical axis 17 (parallel to handlebar 8th ) is perpendicular to the surface 18 , There are therefore no tire side forces to apply the lateral acceleration a _y .

Equation (4) _{logically gives} the value 0 for a _{y_diff} because of the angle ρ '= 90 °. a y_diff = 1 g · tan (ρ) = 1 g · tan (90 ° - 90 °) = 0 (5)

In summary, it can be said that regardless of the inclination of the respective subsoil 11 . 16 . 18 the angle ρ 'between handlebar 8th and crossbeams 9 a direct measure of the respective curve dynamics or for the size of the tire side forces (at least relative to the Reifenvertikalkräfte) provides. Therefore, for example, the angle ρ 'is determined and used for brake control (ABS and / or TCS).

Another exemplary possibility, the curve dynamics in Quasi-Einspurfahrzeug 300 to determine is to attach a conventional lateral acceleration sensor at appro priate place. 2a ) schematically shows another exemplary quasi-single-track vehicle in front view on a horizontal surface 11 , Quasi-wheeler 301 includes according to the in 1a ) described vehicle two front wheels 1 . 2 with front suspensions 3 . 4 , Swivel joints 5 . 6 . 7 , Cross member 9 and handlebar 8th with handlebar 10 , Additionally includes vehicle 301 one parallel to the cross member 9 attached lateral acceleration sensor 20 ,

In 2 B ) is the exemplary quasi-single-track vehicle 301 in front view schematically when cornering with a lateral acceleration a _y on a flat road 11 represented (accordingly 1b )). Will vehicle 301 when cornering through the angle ρ from the vertical axis 12 (perpendicular to the ground 11 ), the acceleration sensor remains 20 due to its parallel position to the cross member 9 in a horizontal position and therefore indicates the actual vehicle dynamics relevant lateral acceleration a _y .

In 2c ) and d) are for comparison the corresponding conditions in a conventional single-track vehicle 400 shown. Even with a single-track vehicle 400 In principle, a lateral acceleration sensor can be used 31 horizontal on the vehicle body 30 attach as in 2c ) shown schematically. However, the vehicle tilts in a curve (angle ρ between the vehicle axle 33 and vertical axis 34 ), as in 2d ), the accelerometer also inclines 31 (Axis 35 ) by the same angle ρ from the horizontal position 36 , so that almost always the lateral acceleration 0 is displayed.

In the tricycle 301 out 2a ) remains so, in contrast to a conventional two-wheeled vehicle 400 corresponding 2c ), the component 9 when cornering in the plane 11 in a horizontal position so that there is a lateral acceleration sensor attached thereto 20 measures the actual lateral acceleration of the vehicle.

Out 1 and 2 Thus, it is apparent that, for example, a measurement of the angle ρ 'and / or a measurement of the transverse acceleration a _y with a horizontal cross member 9 attached sensor 20 is performed to the for the vehicle 300 . 301 relevant lateral acceleration / lateral dynamics with very little effort to capture.

The transverse dynamics estimated according to the above embodiments additionally become, according to a further exemplary embodiment, the relation of the speeds of the two front wheels 1 . 2 hedged. For this purpose, it is assumed that during cornering the speed of the outside wheel is slightly larger than the speed of the inside wheel because of the longer distance to be covered. Between the lateral acceleration a _y , the speed difference Δv of the front wheels 1 . 2 , the driven longitudinal velocity v and the track width b is related: a y = b · v · Δv (6)

The driven longitudinal velocity v is above models from the wheel speeds known, the track width b can for pure monitoring of the relationship is assumed to be constant become.

Based on 3 In the following, a few driving technical extreme cases are briefly presented. The conditions described apply to both vehicle 300 as well as vehicle 301 The illustrations are examples based on the vehicle 301 with acceleration sensor 20 shown.

3a ) shows schematically vehicle 301 when cornering with maximum angle of inclination ρ _max , which can be traversed without any fundamental change in the driving characteristics. Due to the special kinematics of the vehicle 301 , especially the parallel guidance of the components 3 . 4 and 8th , a special minimum angle ρ ' _{min is} given, which can not be undershot. Thus, there are also in 3a ) indicated maximum lateral acceleration a _y ^max , the vehicle still with both running on the ground front wheels 1 . 2 can support.

Will the driver force a higher lateral dynamics, as in 3b ), the high lateral acceleration a _y can only be achieved by an oblique position ρ, which is used to lift off the outside front wheel 1 leads. In this case, the driving mode degenerates, the angle ρ 'can not be smaller than ρ' _min (ρ '= ρ' _min ) due to the vehicle kinematics, the vehicle must be tilted to the inside of the curve, and now the angle relationships apply: ρ> 90 ° - ρ (7) ρ = 90 ° - ρ '+ ρ a (8th) where ρ _{a is} the lateral take-off angle of the vehicle.

Thus, in this degenerate operating case by the measurement of ρ 'no longer the full actual lateral acceleration can be detected. Since also the lateral acceleration sensor 20 now tilts inward and no longer to the road surface 11 is parallel, even the directly measured lateral acceleration is slightly smaller than the actual acting on the vehicle lateral acceleration.

These extreme driving situation will certainly only in rare cases occur, especially since then the inside front wheel alone the full Seitenkraft- and also the entire vertical force must absorb. Therefore, this case is critical in a quasi-single-track vehicle and should be recognized and by the active brake too possibly be corrected. To the case on the part of the brake controller To recognize, for example, an observation the wheel speeds of both front wheels, z. B. the Difference Δv, proposed (see also below).

In 3c ), a further driving state is shown, which can lead to the falsification of the measured lateral acceleration. vehicle 301 drives with front wheel 2 on one level 39 , so that despite a straight ahead driving an angle ρ '<90 ° sets. Also shows the with the cross member 9 inclined lateral acceleration sensor 20 now values not equal to 0 However, such a driving state does not last long. Even if vehicle 301 with front wheel 2 on a sidewalk ridge 39 would run, would have the relatively wide rear wheel either on or below the stage 39 run, making fast driving virtually impossible. On the basis of three identical or almost identical wheel speeds, such a driving state can also be detected in many cases. If recognition is not possible, the condition would be misinterpreted as cornering, so that some control thresholds would be lowered for any regulatory intervention. However, this would be justified again, since the driving condition is classified as quite dangerous, and thus justifies an earlier regulation in each case.

Thus, for a quasi-single-track vehicle, a determination of the effective skew angle ρ (or a measurement of the angle ρ ') and / or a determination of the relevant lateral acceleration component by means of a cross member 9 arranged acceleration sensor 20 the lateral dynamics or cornering recognized. Based on the skew angle ρ (or the angle ρ ') and / or the relevant lateral acceleration component and with the help of the driving speed, which can also be estimated with high accuracy on the basis of the easily measurable wheel speeds, various measures will now be described, which is the anti-lock control for braked Significantly improve wheels or a traction control of the driving rear wheel compared to conventional brake control systems in two-wheeled vehicles.

According to a first embodiment of the invention, each wheel of the tricycle vehicle is equipped with its own speed sensor (eg wheel speed sensor) and a separate brake pressure circuit (brake circuit variant 1 ), preferably the two front wheels 1 . 2 be supplied by a common master cylinder circuit.

According to a second embodiment of the invention, the tricycle is a jointly controlled brake circuit for both front wheels 1 . 2 provided (brake circuit variant 2 ). Each wheel (both front wheels 1 . 2 and rear wheel) is monitored by its own speed sensor (eg wheel speed sensor).

• – Kurvenbremsen, ABS-Regelschwellen, ABS-Früheingriff, Select-Low-Prinzip für Vorderräder, Kompensation von Aufstellmomenten durch Vorderraddruckdifferenz
• – Erkennung des Abhebens eines Vorderrades bei extremer Kurvenfahrt
• – Kurventraktion, BTCS-Regelschwellen, BTCS-Eingriffe bei extremer Kurvenfahrt
• – Modifizierte Integralbremscharakteristik bei extremer Kurvenfahrt
• – Aktiver Raddruckaufbau für die Beeinflussung der Kur vendynamik

The following specific actions are described in detail below:

• - Cam brakes, ABS control thresholds, ABS early intervention, select-low principle for front wheels, compensation of set-up moments by front wheel pressure difference
• - Detecting the lifting of a front wheel in extreme cornering
• - Curve traction, BTCS control thresholds, BTCS intervention in extreme cornering
• - Modified integral brake characteristic in extreme cornering
• - Active Raddruckaufbau for influencing the Kur vendynamik

Cam brakes, anti-skid control:

During the curve braking with a two-wheeled vehicle there is a risk that the front wheel can muster only a little lateral force due to excessive longitudinal force requirement and therefore slips sideways, which then leads directly or indirectly by high steering torque fluctuations to fall. When cornering so should always be carefully built or modulated longitudinal force. According to the above, in the three-wheeled vehicle described above 300 . 301 the lateral dynamics determined and thus a cornering detection are performed. Based on that for the two front wheels 1 . 2 Regelstrate gien performed, which guarantee a safe cornering braking in almost all cases.

According to one embodiment, a gradient limit in the front wheel pressure build-up is activated above a certain threshold for the banking angle ρ and a threshold for the vehicle speed v. The higher the actual driving speed v and the higher the angle of inclination ρ achieved, the more the maximum permitted pressure increase gradient ṗ _{max is} limited. Optionally, the maximum permissible pressure increase gradient ṗ _{max is} also selected as a function of the coefficient of friction μ. Should the driver jerk the brake (s) causing immediate slippage of the front wheels 1 . 2 could lead, so the brake pressure on the gradient restriction so only with a reduced gradient ṗ _max on the front wheels 1 . 2 connected. The vehicle behaves then more homogeneous, and a tendency to block (especially at lower Fahrreibreibwerte μ) can be better recognized and avoided faster with brake pressure holding or brake pressure reduction, without the high excess braking force a longer wheel instability to slippage of the front wheels 1 . 2 leads. This measure of the pressure gradient restriction thus ensures that the first entry into the ABS control takes place homogeneously (without large steering torque fluctuations), and that even with poor road conditions, a sufficiently fast ABS pressure modulation with small wheel slip values is possible.

In 4 an exemplary determination of a situation-dependent gradient limitation is shown. The vehicle speed v is plotted on the abscissa of the diagram, the ordinate represents the maximum pressure increase gradient ṗ _max . The lines 50 . 51 . 52 . 53 represent a set of characteristics for specific parameters of the bank angle ρ, like the parameter arrow 55 (for _high friction μ _high , see also below) indicates. For example, for a small angle of inclination ρ of 20 °, one would still allow a relatively high maximum pressure build-up gradient of about 200 bar / s. With an extreme inclination of 40 °, the pressure increase gradient would be limited to a maximum of approx. 50 bar / s.

Further shows 4 in that the pressure increase gradient ṗ _{max can} advantageously also be varied as a function of the vehicle speed v, in that the maximum permitted pressure increase gradient ṗ _max for a higher speed v is in principle reduced (characteristic curves 50 . 51 . 52 . 53 fall off with increasing v), since the risk of falling or injury is increased at higher speeds. At the maximum speed 54 takes the characteristic 50 therefore the lowest value 57 at.

Like also in 4 represented, the entire characteristic field varies, for example, with an estimated coefficient of friction μ or a Reibwertforgnose. parameter arrow 56 indicates that in the case of a low coefficient of friction μ _low (expected lowest coefficient of friction) changed basic values of the bank angle ρ (10 °, 15 °, 20 °, 25 °) for the family of characteristics 50 . 51 . 52 . 53 can be selected in comparison to the basic values of the angle of inclination ρ (20 °, 25 °, 30 °, 40 °) for parameter arrow 55 for a _high friction μ _high .

A simple (digital) friction coefficient forecast is z. B. via a temperature sensor and a humidity sensor possible. At temperatures below 3 ° C and high humidity, set the expected friction coefficient class to the lowest value (eg μ _low ). At low temperatures and dryness or at higher temperatures and high humidity, a medium coefficient of friction class is selected (eg μ _mid ) and at high temperatures with dryness the highest coefficient of friction class (eg μ _high ) is assumed.

mit

ṗ_base:

großer Basiswert, z. B. 300 bar/s,

k1, k2:

vorgegebene Konstanten, jeweils kleiner als Eins, z. B. 0,3,

v:

aktuelle Fahrzeuggeschwindigkeit,

v_max:

maximal mögliche Fahrzeuggeschwindigkeit,

ρ:

aktueller Schräglagewinkel, und

ρ_max:

kinematisch maximal möglicher Schräglagewinkel (ohne Radabheben, siehe Beschreibung zu 3).

The determination of a limited pressure increase gradient Ṏ _max is alternatively realized by a calculation with the aid of predetermined equations. By way of example, an equation of the following kind is used:

With

ṗ _base :

large underlying value, z. B. 300 bar / s,

k1, k2:

predetermined constants, each less than one, z. 0.3,

v:

current vehicle speed,

v _max :

maximum possible vehicle speed,

ρ:

current skew angle, and

ρ _max :

kinematic maximum possible skew angle (without lifting the wheel, see description to 3 ).

eine lineare Berücksichtigung der Schräglage vor. Es kann aber auch sinnvoll sein, eine hohe Schräglage überproportional zu berücksichtigen, so dass ρ dann beispielsweise mit höherer Potenz in die Gleichung eingehen kann (z. B. ρ²).Equation (9) looks through the term

a linear consideration of the skew before. However, it can also make sense to disproportionately take into account a high skew, so that ρ can then enter the equation with higher power, for example (ρ ² ).

By other terms of this kind in the equation used can considered additional input information be such as the coefficient of friction μ and / or bumps on the roadway. Unevenness of the roadway can be through Model sizes from the brake controller (poor road information, etc.) or additional appropriate sensors are detected, possibly also assigned to other control components of the vehicle are. Such a rule component can, for. B. an active chassis control Be (spring / damper control), the way and / or Vertical acceleration sensors features and based of oscillations or other progressions of these signals performs a classification of the flatness (unevenness) of the soil.

In 5 is shown schematically with the aid of two timing diagrams a cornering braking situation for a front wheel. The upper diagram shows the vehicle speed 60 (v) over the time t and the speed of the braked front wheel 61 shown over time t. In the lower diagram is the brake pressure 62 shown as a function of time t, which the driver feeds via the brake actuation in the master cylinder, which would therefore also without ABS control directly to the considered front wheel. Due to the ABS pressure limitation based on pilot mechanisms and a conventional wheel slip control, this pressure is reduced to the final wheel brake pressure p _v , by the signal 63 is shown.

The above-described exemplary mechanism of gradient limitation in pressure build-up during cornering becomes the first edge 68 the wheel brake pressure 63 driven very flat, so that the braked front wheel is not placed in the unstable area. Before the time 65 diverge vehicle speed 60 and wheel speed 61 Therefore, very slowly apart, the anti-skid control thus has the ability to early recognize and correct an impending blocking tendency of the wheel. This happens in 5 at the time 65 first by holding the wheel brake pressure 63 at a constant level and at the time 66 by a fine removal of the wheel pressure 63 around the small amount 75 , Because of the shallow pressure build-up 68 there is no large brake torque surplus, the small pressure reduction is sufficient 75 to reduce the wheel slip again something. From the moment 67 can the wheel pressure 63 then again through the small pressure build-up stages 69 . 70 be increased slightly. The brake pressure curve 63 thus shows a very low modulation height, whereby the vehicle is braked during cornering very quiet and without instability stimulation.

Would you change the brake pressure set by the driver? 62 Shifting the bike to the wheel with a full gradient would result in a much stronger tendency to lock with deeper slip enemas. Due to the then lower lateral reserve on the front wheels 1 . 2 , these could slip sideways, which in turn could result in a fall.

Particularly critical when braking in bends are poor road friction coefficients. Therefore, pressure build-up should be even more cautious in the case of detected or suspected low friction μ _low . This is in 5 by the dashed line signal of the wheel brake pressure 72 as well as the wheel speed 71 exemplified. The z. B. according to 4 depending on the inclination ρ certain maximum gradient ṗ _max for the pressure build-up is now additionally reduced by the friction coefficient class μ. This leads to the very flat pressure build-up edge 73 in the wheel pressure gradient 72 of the 5 ,

A further exemplary measure to brake the vehicle very stably in curves is to execute the (slip) control thresholds for activating an ABS pressure reduction as a function of the vehicle leaning ρ achieved and likewise dependent on the recognized or assumed coefficient of friction μ. This is exemplified in 6 shown schematically.

In the in 6 1, a slip threshold S _s is plotted as a function of the vehicle speed v. In the case of straight-ahead braking (corresponds to ρ = 0 °), the characteristic curve applies 80 That is, from a slip of 10%, the wheel is considered unstable, and there is a pressure reduction during the ABS control to reduce the wheel slip achieved. By way of example, at a driving speed v of 60 km / h, a slip threshold S _s of 6 km / h (10%) is calculated (operating point 87 ). For low speeds v below 30 km / h, the slip threshold S _s remains constant at a residual value of 3 km / h, so that no Fehlanregelungen done. According to the example, the threshold characteristic will now be 80 Depending on the detected skew angle ρ modified, so that for the parameters ρ = 20 °, 30 °, 35 ° and 40 ° (see parameter arrow 85 ) the characteristics 81 . 82 . 83 and 84 Use (with _high friction μ _high ). These mean that with increasing bank angle ρ of the vehicle it is more likely (even with smaller slip values) to react with ABS pressure reduction. For example, the operating point shifts 87 for 30 ° tilt on the position 88 , The slip threshold S _s for detecting the wheel instability is thus reduced from 6 km / h to 4 km / h.

With the second parameter arrow 86 in 6 is indicated that, for example, when recognized or assumed low friction μ _low one compared to _high frictional μ _high (parameter arrow 85 ) modified threshold modification takes place. According to the illustrated example, the slip threshold S _s at low friction value μ _low already at a vehicle tilt ρ of 12 ° based on the characteristic curve 82 calculated.

Instead of a determination of the slip threshold S _s based on a map such. In 6 represented, the slip threshold S _{s can} also be determined using a predetermined equation, z. B. analogous to equation (9) and the embodiments described there for the maximum pressure gradient.

In addition or as an alternative to the slip threshold S _s , other criteria by which wheel instability is assessed can also be modified via the detected skew ρ. These include z. B. the thresholds for the wheel acceleration or wheel deceleration.

The sensitive ABS control, which is achieved in the case of cornering by the described parameter change (eg adaptation of the slip threshold S _s ), is clearly evident in FIG 5 , The wheel speed (signal 61 in the case of the _high frictional value μ _high, signal 71 in the case of a detected low friction value μ _low ) runs relatively close to the vehicle speed without great dynamics and with low slip fluctuations 60 ,

Based on 7 will be explained below, which consequences arise from the sensitive ABS control for the curve braking behavior of the vehicle. In principle, tire side forces F _{y are} required during cornering in order to support the centrifugal forces of the vehicle. In addition the tire builds according to 7a ) (Radaufsicht) always a certain slip angle α on, so an angle α between its longitudinal direction and the velocity vector in Radaufstandspunkt. By the required lateral force F _y goes out in accordance with the Kamm circle 7b ) available longitudinal force F _x lost. As an approximation, the square root of the squares of the side force F _y and the longitudinal force F _{x is} constant:

Equation (10), conversely, states that when high longitudinal forces F _x (braking forces) are required, the lateral forces F _{y are} reduced. This is also in the exemplary force-slip diagram in 7c ) clear. Depending on the slip angle α, the longitudinal force characteristics shown in solid lines result 102 (for α = 0 °) to 106 (for α = 15 °) as well as the lateral force characteristics shown in dashed lines 108 (for α = 2 °) to 111 (for α = 15 °), which are respectively functions of the percentage longitudinal slip s, whereby according to the general definition:

The sensitive braking force control described above now leads to an increase in the lateral force reserve due to the setting of lower longitudinal slip values s. Is a regulated front wheel, for example, in normal control (according to the prior art) with slip angle α = 10 ° in the operating point 120 on the longitudinal force characteristic 105 and in the point 121 on the lateral force characteristic 110 , These are by a longitudinal force control at a lower slip level (according to an embodiment of the invention) to the operating points 119 and 122 shifted, which corresponds to more lateral force at a slightly reduced longitudinal delay. So there is a tendency to shift the usual work areas 107 and 112 towards the workspaces 113 and 114 , which significantly reduces the risk of a side wheel slipping sideways.

The theoretically reduced in the case of desired full braking Vehicle deceleration is mostly irrelevant in practice, because the vehicle on the one hand very good maneuverability remains and secondly the medium delay due may be very similar to the very homogeneous regulation like with a restless aggressive regulation on a high slip level, the sometimes frequent, strong pressure reduction phases required.

According to a further embodiment, it is proposed (eg suitable for brake circuit variant 1 ), at least during braking with extreme curve dynamics both front wheels 1 . 2 to brake with the same brake pressure curves, with the brake pressure, which is suitable for each of the strongest blocking wheel endanger, so for example for the wheel with the largest slip or the strongest instantaneous delay. This control strategy is customary in the passenger car sector for the wheels of the rear axle and is known per se under the name "select-low strategy." According to the example, this strategy is applied to the front wheels 1 . 2 of the tricycle vehicle, in turn depending on the achieved angle of inclination ρ during cornering (see above).

In another embodiment of the invention, the tricycle vehicle is proposed with a jointly controlled brake circuit for both front wheels 1 . 2 to be provided (brake circuit variant 2 ) and then on the front wheels 1 . 2 in the case of an ABS regulation, in principle, to set a brake pressure which also keeps the wheel most at risk of blockage in a stable slip band (select-low principle).

According to a further embodiment (suitable for brake circuit variant 1 ), only one of the two front wheels is controlled with a cyclic ABS control at the almost optimal longitudinal force point during cornering braking, while the other front wheel is subjected to additional stability needs with slightly reduced pressure, and is thus deliberately provided with more lateral reserve. This control variant, which goes beyond the select-low strategy, is activated, for example, when a low-friction value μ _{low is} assumed during a controlled braking of the curve.

Depending on the kinematics of the front axle, a higher weight can be placed on the outside wheel during cornering, as a result of extreme maneuvers (see eg 3b )), but the driver can also cause the entire front axle weight is on the inside wheel. In order not to slow down in the extreme driving situations, which are not always clearly recognizable on the basis of the wheel speed patterns, the select-low strategy or the extended strategy of pressure control of one wheel below the pressure range of the other wheel is combined, for example, with a slip monitoring of the wheel which tends to be braked , Is the slip too low or a speed pattern is recognizable, the uneven load on the front wheels 1 . 2 indicates, the brake pressure is increased at the wheel with the lower brake pressure after a certain brake pressure build-up pattern until there is sufficient slip, which precludes significant under-braking.

In 8th exemplary speed and brake pressure curves over time t are shown for an extended brake pressure control strategy of one wheel below the pressure range of the other wheel. The wheel speeds 131 and 132 the two front wheels 1 . 2 are due to the slightly different brake pressure curves 134 and 135 at different levels of vehicle speed slip 130 held. With both wheels 1 . 2 becomes the strong pressure target 133 the driver first through the flat gradient 136 for the inside front wheel and 137 significantly limited for the outside front wheel to cut off the surplus energy of braking. The outer wheel becomes the shallower gradient 137 braked so that when jointly holding the speed 131 of the inner wheel due to the reached slip level at the time 138 triggers a small pressure difference between the two wheels, which still gives the outer wheel a very high lateral force reserve. Corresponding 7c ) this means that the inner wheel is more in the working points 120 . 121 So something more aggressive, and the outer wheel rather in 119 . 122 , so something more stable, regulated.

The pressure gradient 135 in 8th shows that the early wheel does not require pressure reduction to maintain stability due to the early pressure hold. This results in a particularly homogeneous braking behavior. If the more endangered inner wheel from the time 140 again with a fine pressure buildup is applied, the brake pressure of the finely controlled outer wheel can either time-delayed by ΔT (only from the time 141 ) or driven so that sets a certain pressure difference .DELTA.P at the two wheels. Furthermore, the pressure on the slightly braked wheel can be controlled so that a minimum slip on the wheel speed 132 established.

According to a further embodiment (suitable for brake circuit variant 1 ) are the two front wheels 1 . 2 the tricycle vehicle in certain situations with different brake pressures applied deliberately to build steering moments and thus to influence the vehicle dynamics. The effects of such brake pressure differences are highly dependent on the kinematics of the front axle and the steering.

Detecting the lifting of a front wheel:
An extreme driving state of the tricycle vehicle is that at very high transverse dynamics, the outside front wheel lifts off, because the driver shifts his weight to the inside of the curve to achieve a higher lateral acceleration a _y with the increased banking angle ρ than is possible due to the limited vehicle kinematics ( please refer 3b ) and description). This driving condition can occur during both braking and acceleration and is dangerous in any case. Therefore, it is an object of the invention to clearly recognize this situation.

In 9 exemplary speed signals of both wheels during a lifting of the outside front wheel are shown as a function of time t. In 9a ) is the case of braking, in 9b ) illustrates the case of acceleration. The signals 145 respectively. 151 represent the vehicle reference speed, the signals 147 respectively. 152 put the contrasting, outside front wheel and the signal 146 the curve inner front wheel, the ground contact retains, dar.

In the braked case (see 9a )) the outside wheel (signal 147 ) after loss of ground contact force at the time 148 Even due to the lowest residual braking force block, since the anti-lock braking system (ABS) normally can not reduce the brake pressure sufficiently fast and not exactly to 0 bar. After a defined time, in the example at the time 149 , it is expected that a wheel with ground contact force with appropriate braking pressure reduction by the control system back up to the vehicle reference speed 145 or to the speed 146 of the other front wheel accelerates. If this is not the case, it is assumed that a lifting wheel. In the example shown, the unbraked wheel accelerates abruptly at the time 150 , This is interpreted as a restart of the wheel.

• – das Fahrzeug eine extreme Querdynamik erreicht hat,
• – das Fahrzeug noch mit einer Mindestgeschwindigkeit (von z. B. 10 km/h) fährt, und
• – das Vorderrad trotz ABS-Regelung über einen definierten Mindestzeitraum blockiert.

By way of example, lifting of a front wheel is detected when during braking

• - the vehicle has reached extreme lateral dynamics
• - the vehicle is still running at a minimum speed (eg 10 km / h), and
• - blocked the front wheel despite ABS control over a defined minimum period.

In the accelerated case (see 9b )), the outside front wheel is not accelerated with the vehicle due to the lack of grip. So although the driving speed 151 of the vehicle increases, the wheel speed remains 152 of the outside front wheel at Abhebe time 153 at the achieved level and even slightly delayed due to the bearing friction. In case of restarting at the time 155 the wheel is abruptly accelerated again. The lift-off case can after a defined time, in the example at the time 154 to be taken for granted.

• – das Fahrzeug eine extreme Querdynamik erreicht hat,
• – das Fahrzeug mit einer Mindestgeschwindigkeit (von z. B. 10 km/h) fährt,
• – das Vorderrad über einen definierten Zeitraum ohne Bremskraft einen Mindestschlupf zur Fahrzeuggeschwindigkeit aufweist, und
• – das Vorderrad mit leichter Verzögerung läuft.

By way of example, lifting of a front wheel is detected when during acceleration

• - the vehicle has reached extreme lateral dynamics
• - the vehicle is traveling at a minimum speed (eg 10 km / h),
• - The front wheel has a minimum slip to the vehicle speed over a defined period of time without braking force, and
• - the front wheel is running with a slight delay.

Traction Control, TCS (Traction Control System, Traction Control Engine and Brake Interventions), BTCS (Brake Traction Control System, Traction Control Brake Only):
According to the example, a traction control system (TCS or BTCS) is adapted in the case of an accelerated cornering depending on the achieved lateral dynamics (skew ρ and / or lateral acceleration a _y ). For this purpose, entry thresholds (eg drive slip thresholds) and / or control parameters (eg engine torque and / or brake pressure, their gradients) of the traction control are determined on the basis of predetermined, eg. B. adapted to the vehicle, characteristics or equations in dependence of the skew angle ρ determined. These can additionally be determined as a function of the assumed coefficient of friction μ.

The Possible procedures are analogous to those in the case anti-skid control procedures / measures carried out. Since the procedures / measures for the ABS have already been explained in detail above, At this point only a short summary will be given. The for a ABS discussed procedure can be analogous, taking into account the special features described below, transferred to traction control system, and there described embodiments apply accordingly also for the traction control.

By way of example, a BTCS will initiate the brake pressure buildup at the tractor rear wheel in the event of an impending wheel spin earlier, the higher the lateral dynamics (banking angle ρ and / or lateral acceleration a _y ) and the lower the assumed road friction coefficient μ.

Likewise, for example, in TCS with engine intervention, the corresponding thresholds for the reduction of the driving engine torque are adapted. The goal is always to keep the traction of the rear wheel at high cross-dynamics always low. For the lateral force reserve and thus the driving stability of the rear wheel is in principle the same statement as for the front wheels when braking. The diagram 7c ) is also valid as a traction diagram with the opposite sign. Accordingly, according to an embodiment of the invention, the operating points of the rear wheel on the force characteristics tend to 120 and 121 to 119 and 122 , that is shifted into the range of smaller slip values when an extreme cornering is detected (see 7c )).

All relevant parameters and criteria for the assessment of the drive wheel stability in the BTCS or TCS can, analogously to the description for the front wheels in ABS, via parameter fields (such as in the 4 and 6 for the ABS) or equations (eg according to equation (9)) as a function of the vehicle transverse dynamics or the soil quality (eg coefficient of friction, flatness).

According to one embodiment, the traction control system (BTCS or TCS) is already activated when, during a strong curve traction lifting the kurvenäu ßeren front wheel in accordance with in connection with 9b ) is detected. The activation can be done in such cases so without any visible traction slip on the rear wheel. The intervention is terminated or at least reduced when the respective front wheel accelerates again in the range of the vehicle speed (time 155 in 9b )).

ABD (Active Brakeforce Distribution), integral brake during corner braking:
For comfortable braking of a single-track vehicle with two separate brake actuation elements (eg hand brake lever and foot brake lever), integral brake systems with so-called ABD function (Active Brake Force Distribution) are known from the prior art. For example, if the driver presses the front brake (handbrake lever), this initially acts only on the front wheel due to direct hydraulic penetration. Likewise, the rear wheel brake circuit is designed separately to ensure the legally required dual-circuit braking system. In order to allow the driver to brake both wheels with just one actuator, the ABD function performs active braking in the not directly manually operated brake circuit. The metering of this active brake pressure paktiv occurs as a function of the brake pressure p _HZ in each actuated brake circuit. For this purpose, at least one braking force distribution characteristic is stored (corresponding to a functional relationship f, where p _active = f (p _HZ )).

Such an integral braking function with ABD can be implemented analogously for a quasi-single-track vehicle. According to the invention, the braking force distribution characteristic or the functionally related f as a function of the transverse dynamics (the skew angle ρ and / or the lateral acceleration a _y ) are specified.

Exemplary braking force distribution characteristics are in 10 shown. The characteristics 160 to 163 apply to actuation of the front brake circuits (p _HZ ) with active brake pressure build-up (p _active ) in the rear wheel, the characteristics 164 to 167 apply to actuation of the rear wheel brake circuit (p _HZ ) with active brake pressure build-up (p _active ) on the front wheels.

For straightforward braking with ρ = 0 °, use the characteristic curve 160 out of value 169 of the brake pressure of the master cylinder p _{HZ of} the front wheels, which the driver himself prescribes with the brake lever, of the ABD function a value 170 for the rear brake pressure p _actively requested and realized by the pressure regulator of the brake control device by means of hydraulic pump and valves. curve 160 is degressive, as with increasing brake pressure an increased vehicle deceleration is achieved and thus weight is dynamically shifted from the rear wheel to the front wheels, so that the relieved rear wheel tends to block more.

In the other case, upon actuation of the brake lever for the rear wheel brake circuit, a pressure applied by the driver is applied 174 in the master cylinder of the rear wheel circle over the characteristic curve 164 (for straight ahead travel with ρ = 0 °) into a corresponding print request 175 implemented for the front wheel brake circuits. curve 164 Runs progressively, as with increasing brake pressure, an increased vehicle deceleration and thus dynamically shifting weight from the rear wheel to the front wheels, so that the front wheels can cope with more brake pressure without blocking.

The characteristics 160 and 164 are designed so that the braking force set on each wheel behaves ideally proportional to its Aufstandskraft (ideal braking force distribution). The characteristics 160 and 164 However, are optimal only for the case of straight-braking, for corner braking, it is recommended to calculate the requested wheel brake pressure _active p _active on the active wheel, otherwise the wheels build too much longitudinal slip and an ABS situation can occur, with the driver due to a relatively moderate activity does not count.

By way of example, therefore, for the cornering, a family of curves according to the characteristics 161 . 162 . 163 for active pressure build-up on the rear wheel and according to the characteristic curves 165 . 166 . 167 for the active pressure build-up on the front wheels, whereby the respective characteristic curve selection again takes place on the basis of the achieved tilt angle ρ (basic values 20 °, 30 ° and 40 °, see parameter arrow 168 ).

At a front wheel braking with the pressure 169 at an angle of 20 ° shifts according to the example of the operating point 171 to 173 , At the rear wheel then only the pressure 172 instead of 170 actively controlled. Accordingly, in a rear wheel brake with the pressure 174 at an angle of 30 ° the operating point 176 to 178 move. At the front wheel then only the pressure 177 instead of 175 requested.

For the embodiment of the invention, which includes two separately controllable brake circuits for the front wheels (brake circuit variant 1 ), the ABD characteristic curves for the active pressure build-up on the front wheels (characteristic family) are, for example, in the event of partial braking in curve situations with high lateral dynamics 164 to 167 in 10 ) run slightly differently on both front wheels, the curves for the outside wheel are higher or lower than the curves for the inside wheel. This can affect the curve dynamics of the vehicle in the partial braking, with an amplified or reduced steering torque is generated. Due to the pressure difference on the two front wheels so the driven curve radius can be easily influenced. For example, in a slippery road surface (low coefficient of friction), the curve radius is slightly increased.

Curve stability control, active pressure build-up on one or more wheels and / or engine intervention:
According to a further embodiment of the invention, an active steering torque is generated in certain situations of extreme cornering by an active pressure build-up takes place by the brake controller on the inside or outside of the curve or on the rear wheel.

On This way can be additionally achieved that the speed v the vehicle is actively reduced slightly to the vehicle so out of the critical cornering range. The necessary ones (Brake) interventions depend heavily on the Kinematics of the front axle and other parameters of the suspension.

To perform a vehicle dynamics control (similar to an ESP control (Electronic Stability Program) in the car) is, for example on the cross member 9 of the vehicle (see 1 and 2 ) a lateral acceleration and yaw rate sensor (not shown in a figure). Based on these data a _y , ψ. derived vehicle models and the driver behavior are calculated, if necessary, the active wheel pressures that are necessary to influence the driving dynamics. Alternatively, the lateral acceleration signal is derived from the skew angle ρ (see description above) 1 ).

about the yaw rate signal can also slip sideways of the rear wheel detected and through during a strong curve traction appropriate engine and brake interventions are suppressed (TCS or BTCS).

By example a regulation is performed when the driver during an acceleration process there is too much gas in the bend. As a result, the rear wheel Slightly slips sideways, resulting in an abrupt increase in the yaw rate can be recognized. Under the scheme then a slight braking the outside front wheel and possibly in addition the rear wheel performed. Additionally or alternatively, by the control, a gas take-off (engine intervention) carried out.

In 11 FIG. 3 is a schematic block diagram of an exemplary joint implementation of some of the above-described example functions (function blocks) 201 . 202 and 203 ) and their integration into an existing standard control system 200 with known ABS, TCS, ABD and driving stability control functions.

In block 201 a signal conditioning, ie conversion, scaling and filtering, the recorded sensor signals is performed. In the simplest case, only the angle ρ 'between the cross member 9 and the steering column 8th of the vehicle (see 1a )) detected. Alternatively or additionally, the transverse acceleration signal a _y directly on the cross member 9 attached acceleration sensor ( 20 in 2 ) used. In addition, on the cross member 9 Also, a yaw rate sensor may be mounted so that a measured yaw rate ψ. can be used for regulation.

The processed signals 207 be on block 202 which essentially includes modeling such as simple wheel pattern monitoring for front wheel liftoff detection and general danger logic that detects extreme curve situations. To clearly identify the driving conditions, the danger computer 201 in addition to the speeds of the three wheels and the brake pressures in the two main cylinders (signals 204 ) and, if available, information about (soil) humidity and air temperature (signals 205 ) and information 206 supplied via the roadway quality. The humidity and air temperature signals 205 can z. B. supplied by simple corresponding sensors; the information 206 about the flatness of the road can for example be supplied by a chassis controller (spring / damper) via a data bus system (CAN, etc.). Furthermore receives the danger calculator 202 For example, the generally in brake controls 200 available model and reference signals 208 , These include the estimated vehicle speed v and vehicle deceleration.

risk calculator 202 activated via the hazard information 209 the calculation of parameters and control thresholds in block 203 , This includes block 203 Characteristic fields (eg according to the 4 . 6 and 10 ) and / or continuous calculation instructions (eg according to equation (9)).

The in block 203 calculated control parameters and control thresholds are transmitted along with corresponding control signals via line 210 the standard controller 200 fed. standard controller 200 then performs a correspondingly modified control and passes the necessary pressure requirements for the wheel brake circuits via line 211 to a pressure control device and the torque requests via line 212 (For example, realized by a data bus, CAN, etc.) to an engine control unit on.

According to another embodiment additionally provides block 203 Even in critical driving situations active brake pressure and engine torque requirements. The requirements are also over line 210 the control system 200 which then coordinates the requirements with its internal requirements and over the lines 211 and 212 continues. This is block 203 Also able to perform by active braking and engine interventions a similar today's car ESP regulation.

• – Durch die besondere Kinematik der Vorderradaufhängung ergibt sich eine sehr einfache Möglichkeit, die effektiv auf das Fahrzeug wirkende Querbeschleunigung bzw. die Seitenkräfte an den Rädern genau abzuleiten.
• – Auf der Basis der bekannten Seitenkräfte können zahlreiche Funktionen in ABS und TCS verbessert werden, insbesondere können Schwellen für Regelungseingriffe sowie die Stärke der aktivierten Eingriffe modifiziert werden. Die Berechnung von Schwellen und Reglerparametern kann direkt als Funktion (quasi analog oder gestuft) der Seitenkräfte erfolgen. Durch diese mehr auf Stabilität ausgelegte Längskraftregelung, wird indirekt die Querdynamik des Fahrzeugs so beeinflusst, dass möglichst auch die sonst für Einspurfahrzeuge kritischen Manöver bei extremer Kurvenfahrt optimal bewältigt werden.
• – Eine weitere Möglichkeit einer stabilen ABS-Regelung während einer Kurvenbremsung kann darin bestehen, beide Vorderraddrücke gleich oder nahezu identisch zu wählen, obwohl die Blockierneigungen der Räder verschieden stark sind. Durch diese Maßnahme ist es möglich, eine zusätzliche Seitenkraftreserve an den Vorderrädern aufzubauen, die der Fahrstabilität des Fahrzeugs zugute kommt.
• – Mit Hilfe der zwei Vorderräder können bei Bremseneingriffen sowohl im Falle einer passiven Druckmodulation (beispielsweise für ABS oder auch während einer Normalbremsung der Vorderräder durch den Fahrer) als auch im Falle von aktiven Druckaufbauten (beispielsweise für eine Integralbremsfunktion) bewusst Druckdifferenzen an den beiden Vorderrad-Bremskreisen eingestellt werden, die das Fahrverhalten des Dreirads in der jeweils gewünschten Weise beeinflussen.

For the antiskid control (ABS) and traction control (TCS) of a quasi-single-track vehicle with two front wheels and one rear wheel compared to the real single-track vehicle thus resulting in significant benefits listed below:

• - Due to the special kinematics of the front suspension gives a very simple way to accurately deduce the effective acting on the vehicle lateral acceleration or the lateral forces on the wheels.
• On the basis of the known lateral forces numerous functions in ABS and TCS can be improved, in particular thresholds for control interventions and the strength of the activated interventions can be modified. The calculation of thresholds and controller parameters can be carried out directly as a function (quasi analog or stepped) of the lateral forces. This more stability-oriented longitudinal force control indirectly influences the lateral dynamics of the vehicle in such a way that optimally manages the maneuvers that are otherwise critical for single-track vehicles during extreme cornering.
• - Another way of stable ABS control during cornering braking can be to choose equal or almost identical to both front wheel pressures, although the block inclinations of Ra which are different strong. By this measure, it is possible to build an additional lateral reserve on the front wheels, which benefits the driving stability of the vehicle.
• - With the help of the two front wheels, both in the case of passive pressure modulation (for example, for ABS or during normal braking of the front wheels by the driver) and in the case of active pressure structures (for example, for an integral brake function) deliberately pressure differences at the two front wheel Brake circuits are set, which influence the driving behavior of the tricycle in the desired manner.

According to one Embodiment, the invention treats a brake control system for a quasi single-track vehicle with two front wheels, a rear wheel and three separately adjustable Raddruckkreisen, in which to optimize the brake control functions, the lateral dynamics of the vehicle is taken into account. For this purpose, z. B. the angle between one always parallel to the road surface standing (ie as horizontally assumed) and the front measured in curves tilting steering axle and as a measure of the driving dynamics relevant inclined position (roll angle) assumed and from this a lateral acceleration or a substitute variable calculated, with the inclination or the roll angle itself or one of the derived quantities as driving dynamics relevant sizes is used to determine the degree of Define transverse dynamics or the criticality of a cornering. According to an alternative embodiment is on the wheel carrier parallel to the road surface directly attached a lateral acceleration sensor and / or a yaw rate sensor, so that in this plane, usually parallel to the road level, measured signals as the driving dynamics considered relevant proportions of a lateral acceleration or yaw rate and used directly to optimize the brake control functions become.

According to one Another embodiment is in the brake control system the estimated lateral dynamics additionally by the Relation of the speeds of the two front wheels secured. It is assumed that while cornering the speed of the outside wheel because of the extended path to be covered a bit larger is the speed of the inside wheel.

The Brake control functions is in case of cornering z. Eg not only in dependence of the detected lateral dynamics, but additionally dependent on a recognized or suspected Friction value class optimized. The coefficient of friction class gives a rough idea Classification of the global expected road friction coefficient and is determined by simple signals, such as the measured ones Air temperature and (road) moisture. additionally or alternatively, the brake control functions in the case of Cornering depending on a detected or suspected Unevenness of the road surface optimized.

All significant control thresholds and control parameters for a ABS control are in one embodiment of the recognized degree of lateral dynamics, to the recognized coefficient of friction class and / or adapted to the recognized unevenness of the roadway. Especially the maximum pressure build-up gradient with which the wheel brake pressure is outside an ABS control may be increased, and / or the pressure increase gradient, with which increases the brake pressure of a wheel within an ABS control may be used to approach the expected stall pressure, and / or the sensitivity of blocking detection, d. H. all wheel slip and acceleration thresholds that are needed to the Stability or instability of a braked Rades are adapted to be adapted.

In the brake control system z. B. all significant control thresholds and control parameters for an ABS control such to the recognized degree of lateral dynamics and to the recognized coefficient of friction class adapted that the mean longitudinal slippage, in particular at the front wheels of the tricycle, the lower is set, the higher the lateral dynamics and the lower the detected coefficient of friction is.

According to one Another embodiment of the brake control system the two front wheels of the tricycle in the case of a recognized critical curve braking after entering the ABS regime regulated according to the select-low principle, d. H. that in both Vorderradkreise be fed at any time the same pressure values, where each the front wheel with the strongest blocking tendency, So the wheel with the biggest slip or the biggest delay, the common Wheel pressure determined.

alternative are the two front wheels of the tricycle only with equipped with a commonly controlled brake circuit and, in particular in the case of a recognized critical cornering, the common Brake pressure after entering the ABS control according to the select-low principle regulated by supplying pressure values at all times, the front wheel that tends the most to block Keep in a stable slip band.

in the Trapped extreme cornering braking becomes the wheel brake pressures z. B. modified so that only on the inside front wheel a cyclic ABS control with pressure increase and decrease at the optimum point of the longitudinal force characteristic is executed, while preferably the outside of the curve Front wheel to achieve a higher lateral reserve is deliberately slightly braked by its brake pressure slightly below the pressure of the inner wheel is maintained.

According to one Embodiment of the traction control system are all significant control thresholds and control parameters for a Traction control to the detected degree of lateral dynamics, to the recognized Reibwertklasse and adapted to the recognized unevenness of the road. In particular, the sensitivity of the detection of the spin traktierenden rear wheel, so all Radschlupf- and acceleration thresholds, which are needed to stability or instability of the tractioning wheel (rear wheel) are adapted.

Z. B. all essential control thresholds and control parameters for a TCS control in such a way to the recognized degree of lateral dynamics and adapted to the recognized coefficient of friction class that the average longitudinal drive slip adjusted at the traktierenden rear wheel of the tricycle vehicle the lower becomes, the higher the transverse dynamics and the lower the recognized Friction coefficient is.

According to one Embodiment of a brake control system with integral function become the braking force distribution characteristics for an ABD control (Active Brake-Force Distribution) in such a way the recognized degree of Transverse dynamics and adapted to the recognized coefficient of friction that that Wheel, which is slowed down by the active pressure build-up of the ABD, preferably not brought to the blocking limit.

According to one another embodiment of a brake control system with integral function are in case of partial braking in curves for active ABD pressure build-up on the two front wheels provided different characteristics, so that by the pressure difference on the front wheels a strengthening or weakening Steering torque is effected.

to Detection of the lifting of the outside front wheel of the tricycle during an extreme cornering be z. B. the speeds of the three wheels permanently monitored and checked for characteristic patterns. This is a non-adjustable blocking of the outer Front wheel during a standard braking or not Accelerating, but slightly delaying outer Front wheel during strong traction as an indication of a lift of the wheel scored.

One recognized lifting of the outside front wheel during an extreme regulated corner braking release according to one embodiment a modified ABS control for the inside wheel, this then to achieve an improved lateral reserve is regulated with a lower level of slip.

According to one another embodiment of the brake control system triggers a recognized lifting of the outside front wheel of the tricycle during an extreme controlled Kurtraraktion an early TCS regulation at the traktierenden Rear wheel, without this an unstable traction must have.

at detected extreme cornering is z. B. a brake pressure on a the front wheels or the rear wheel or at the same time several wheels actively built to the curve dynamics of the Vehicle influence and / or in some cases the Driving speed easy to reduce.

As well can be detected when extreme cornering on the observation the Fahrzeuggierrate on a lateral breakout of the rear wheel be closed and in the recognized case the vehicle by reduction the engine torque and / or by appropriate active braking interventions be stabilized on one or more wheels.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - EP 0548985 B1 [0002]
• - DE 4000212 A1 [0002]
• - DE 3803563 A1 [0003]
• - DE 10316351 A1 [0003]
• DE 102005003255 A1 [0004]
• - DE 60110308 T2 [0007]

Claims (19)

Method in which a control in an electronically controlled control system of a quasi-single-track vehicle ( 300 . 301 ), which has two front wheels ( 1 . 2 ), a rear wheel and a handlebar ( 8th ), the front wheels ( 1 . 2 ) and the handlebar ( 8th ) with a front cross member ( 9 ), in particular via swivel joints ( 5 . 6 . 7 ), are connected such that the front cross member ( 9 ) while driving substantially parallel to the road surface ( 11 . 16 . 18 ), while the handlebar ( 8th ) is aligned substantially parallel to the inclined position (ρ) of the vehicle, characterized in that - an angle (ρ ') between the steering rod ( 8th ) and front cross members ( 9 ), and / or - that by means of at least one sensor ( 20 ) at least one transverse dynamic quantity (a _y , ψ.) is determined, wherein the sensor ( 20 ) on the front wheel cross member ( 9 ), in particular parallel to the front wheel cross member ( 9 ), wherein a brake pressure control ( 211 , p _active ), in particular according to a braking force distribution, and / or an engine torque control ( 212 ) and / or a Radabhebeerkennung and / or a vehicle dynamics control in dependence of the angle (ρ ') and / or the transverse dynamics quantity (s) (a _y , ψ.) Is performed / be performed. Method according to claim 1, characterized in that by means of an acceleration sensor ( 20 ) a lateral acceleration (a _y ) and / or a yaw rate (ψ) is determined by means of a yaw rate sensor, and as a transverse dynamics variable (s) for brake pressure regulation ( 211 , p _active ) and / or engine torque control ( 212 ) and / or Radabhebeerkennung and / or vehicle dynamics control is / will be used. A method according to claim 1 or 2, characterized in that from the angle (ρ ') between the handlebar ( 8th ) and front cross members ( 9 ) and / or the transverse dynamics variable (a _y ) a banking angle (ρ) of the vehicle is determined, wherein a brake pressure control ( 211 , p _active ) and / or an engine torque control ( 212 ) and / or a Radabhebeerkennung and / or a vehicle dynamics control in dependence of the inclination angle (ρ) is performed / be performed. Method according to at least one of claims 1 to 3, characterized in that a detection of cornering and / or a curve braking on the basis of the angle (ρ ') between the handlebar ( 8th ) and front cross members ( 9 ) and / or the transverse dynamics quantity (a _y ) and / or the skew angle (ρ). Method according to at least one of claims 1 to 4, characterized in that the wheel rotational speeds of the two front wheels are detected and compared, and in particular additionally the wheel rotational speed of the rear wheel is detected, and - to check the specific transverse dynamics (a _y , ρ ') and / or the specific angle of inclination (ρ), and / or - for cornering detection, and / or - for brake pressure control ( 211 , p _active ) and / or engine torque control ( 212 ) and / or Radabhebeerkennung and / or vehicle dynamics control are used. Method according to at least one of claims 1 to 5, characterized in that in a recognized cornering the brake pressure control ( 211 , p _active ) and / or the engine torque control ( 212 ) and / or the vehicle dynamics control in dependence on a coefficient of friction variable (μ) and / or a road surface measurement size representing a unevenness of the road surface is / is performed. Method according to at least one of claims 1 to 6, characterized in that at least one control threshold (S _s ) and / or at least one control parameter (ṗ _max , p _active ), in particular a brake pressure build-up gradient (ṗ _max ), a control function of the angle ( ρ ') between handlebar ( 8th ) and front cross members ( 9 ) and / or the transverse dynamics quantity (a _y ) and / or the banking angle (ρ) and / or the coefficient of friction (μ) and / or the road surface measurement and / or the vehicle speed (v) is adjusted, the dependency ( s) of the variables from each other in particular in the form of at least one characteristic or a characteristic field or at least one functional relationship is / are predetermined. Method according to at least one of claims 1 to 7, characterized in that in an anti-lock control at a detected braking curve, in particular a recognized critical cornering braking, same braking pressures at the two front wheels ( 1 . 2 ) are set, in each case the Vor the larger slip and / or the greater deceleration determines the anti-lock control. Method according to at least one of Claims 1 to 7, characterized in that, in the case of a recognized braking of a curve, in particular a recognized critical braking of the curve, the brake pressures at the two front wheels ( 1 . 2 ) are regulated differently, in particular, the brake pressure of the outside front wheel is set lower than the brake pressure of the inside front wheel. Method according to at least one of claims 1 to 9, characterized in that at a detected cam braking below an entry into an anti-lock control different brake pressures at the two front wheels ( 1 . 2 ) are actively set as a result of a braking force distribution control of an integral braking function (ABD). Method according to at least one of the claims 1 to 10, characterized in that for the inside of the curve Front wheel performed a modified anti-skid control is, if at a detected corner braking, in particular one recognized critical curve braking, a lift off the outside front wheel is recognized, in particular, the inside of the front wheel with a lower level of slippage is regulated. Method according to at least one of the claims 1 to 11, characterized in that a traction control on Rear wheel is initiated when, during a recognized cornering, in particular a recognized critical cornering, a takeoff of the outside front wheel is detected, too when traction slip criteria for initiating traction control on the rear wheel are not fulfilled. Method according to at least one of the claims 1 to 12, characterized in that at a recognized critical Cornering brake pressure is actively building on at least one wheel, in particular such that the vehicle speed (v) is reduced is and / or the driving dynamics of the vehicle is affected. Method according to at least one of the claims 1 to 13, characterized in that an active brake pressure control performed on at least one wheel and / or an engine torque reduction is when a detected critical cornering on the basis of Yaw rate (ψ.) A lateral breaking of the rear wheel is detected. Electronic control system in a quasi-single-track vehicle ( 300 . 301 ), which has two front wheels ( 1 . 2 ), a rear wheel and a handlebar ( 8th ), the front wheels ( 1 . 2 ) and the handlebar ( 8th ) with a front cross member ( 9 ), in particular via swivel joints ( 5 . 6 . 7 ), are connected such that the front cross member ( 9 ) while driving substantially parallel to the road surface ( 11 . 16 . 18 ), while the handlebar ( 8th ) is aligned substantially parallel to the inclined position (ρ) of the vehicle, characterized in that - this means a means for determining an angle (ρ ') between the handlebar ( 8th ) and front cross members ( 9 ) or with a means for determining an angle (ρ ') between the steering rod ( 8th ) and front cross members ( 9 ), and / or - that this at least one sensor ( 20 ), which determines at least one transverse dynamic quantity (a _y , ψ.), or comprises at least one sensor ( 20 ), which determines at least one transverse dynamic quantity (a _y , ψ.), wherein the sensor ( 20 ) on the front wheel cross member ( 9 ), in particular parallel to the front wheel cross member ( 9 ), wherein the angle (ρ ') and / or the transverse dynamic quantity (a _y , ψ.) To a brake pressure control ( 211 , p _active ) and / or to an engine torque control ( 212 ) and / or to a Radabhebeerkennung and / or to a vehicle dynamics control is / are used. Control system according to claim 15, characterized in that the sensor ( 20 ), which determines a transverse dynamic quantity (a _y , ψ.), an acceleration sensor ( 20 ) and / or a yaw rate sensor. Control system according to claim 15 or 16, characterized characterized in that the quasi-single-track vehicle three separately controllable Wheel brake circuits for the two front wheels and the rear wheel covers. Control system according to claim 15 or 16, characterized characterized in that the two front wheels of the quasi-single-track vehicle over be controlled a common wheel brake. Control system according to at least one of claims 15 to 18, characterized in that this comprises a control device in which a method according to any one of claims 1 to 14 is performed.