DE102008026531A1 - Brake pressure controlling method for electronically controlled brake system of motor cycle, involves setting retaining brake pressure in rear wheel brake circuit, and determining retaining brake pressure - Google Patents

Abstract

The method involves setting retaining brake pressure in a rear wheel brake circuit after stopping or approximate stopping of a motor cycle (30) by a driver. The retaining brake pressure is determined from the brake operating pressure of a front wheel (VR) and the brake operating pressure of a rear wheel (HR) which are required for stopping the motor cycle. The retaining brake pressure is determined depending on a vehicle delay obtained during stopping.

Description

The The invention relates to a method according to the preamble of claim 1 and an electronic brake system according to the preamble of claim 10.

The Motorcycle has been a cost-effective over the past few decades Means of transportation developed into a recreational vehicle, which increases both safety and comfort the driver is brought to the foreground.

Similar to automobiles a few years ago, motorcycles are increasingly equipped with anti-lock braking systems (ABS). From the EP 0 548 985 B1 For example, an anti-lock device for motorcycles is known.

Due to the increased safety and / or the increased comfort integral braking systems are used in motorcycles, which support the driver during braking and thus ensure an optimized braking distance. An "integral brake system" is understood to mean a brake system in which a brake of the other brake circuit, eg by an active pressure build-up, is additionally braked when the handbrake lever or the footbrake lever is actuated, ie both brakes can be actuated by actuating a single actuation element Integral brake systems for motorcycles are for example from the DE 38 03 563 A1 and DE 103 16 351 A1 known.

Furthermore In the field of motorcycles, driver assistance systems are increasingly gaining in importance in importance. In particular, the demand for cost-effective increases Driver assistance systems that utilize the existing hardware, to carry out further comfort and / or safety functions.

Among the above-mentioned motorcycle driver assistance systems include systems with stop and start-up function, which the motorcycle at a standstill, z. B. on a slope, hold and allow on request of the driver a start. An electronically controlled braking system with stopping and starting function for a motorcycle is used in the DE 10 2007 025 273 A1 described. In this case, the size of the holding brake pressure is selected as a predetermined, constant value or as a function of the loading condition of the motorcycle, the type of motorcycle and / or the gradient measured by a longitudinal acceleration sensor.

Of the Invention is based on the object, a method for holding a Motorcycle at a standstill and an electronic brake system for to provide a motorcycle, which is a safe Keep the motorcycle, even on a slope, guaranteed.

These The object is achieved by the method according to claim 1 and the electronic brake system solved according to claim 10.

Of the Invention is based on the idea, the size / strength the holding brake pressure, which to prevent rolling away a motorcycle at a standstill or near-stopping in a wheel brake circuit after stopping the motorcycle by a driver is built and maintained depending on a brake actuation pressure of the front wheel and a Brake actuation pressure of the rear wheel to determine which needed to stop the motorcycle. hereby the motorcycle is also without further actuation of a brake actuator held securely by the driver. In addition, the operation and the strength of the operation of the individual brake actuators considered for front and rear wheel of a motorcycle.

Around a greater stabilization of the motorcycle too reach, the holding brake pressure is preferred in the rear wheel built up.

When to stop necessary brake actuation pressure of the front wheel and / or the rear wheel is preferred at the time of Stop brake actuation pressure selected. Around a more reliable determination of brake actuation pressure Alternatively, it is preferred to apply the brake actuation pressure as an average of brake actuation pressures of the corresponding one Rades over a given period during of arrest.

Of the Brake actuation pressure of a wheel is preferred a pressure sensor determines which is a master cylinder pressure determined. Such is an accurate determination of the brake actuation pressure guaranteed. To the brake actuation pressures of both Wheels can be determined with sufficient accuracy preferably both the brake actuation pressure of the front wheel as well as the brake actuation pressure of the rear wheel respectively determined by a pressure sensor, which is the master cylinder pressure determined the respective wheel brake.

According to a preferred embodiment of the invention, the holding brake pressure is additionally determined as a function of a vehicle deceleration achieved during the stop. By taking into account the achieved vehicle deceleration at known brake actuation pressures of the wheels, it is a consideration of the road inclination is enough, whereby a situation-adapted design of the holding pressure is achieved. This also has the advantage that the road inclination is taken into account without an additional sensor for measuring the inclination of the roadway must be mounted on the motorcycle.

Prefers is determined by at least one brake actuation pressure and the vehicle deceleration achieved during the stop determines the road inclination, and the holding brake pressure then depending the road inclination chosen. The particular roadway inclination can then also be taken into account by other vehicle control systems, z. As in the dimensioning of the brake pressure reduction in a start-up function. As a result, an additional sensor for measuring the Track inclination saved.

According to one advantageous development of the invention is the roadway inclination based on given characteristics or a given map or based on a given functional relationship from the / Brake actuation pressure (s) and vehicle deceleration (a) determined. Here is / are the characteristics or the map or the functional relationship specified vehicle-specific. Appropriate Specifications are particularly preferred in a control unit of Motorcycle, most preferably in the brake control unit of the motorcycle, filed. By a purely technical evaluation Determination of the road inclination angle from already existing in the vehicle Sizes or easily determinable sizes (Brake actuation pressure and deceleration) Costs, z. B. for a tilt sensor, saved.

Prefers is the holding brake pressure as a sum of a base value and formed a roadway slope-dependent pressure value. there the base value is the brake actuation pressure of the front wheel and the brake actuation pressure of the rear wheel, which were necessary to stop the motorcycle. hereby is a separate consideration of actuation-dependent holding pressure share and road grade dependent holding pressure fraction achieved which also in the case of a faulty certain roadway inclination at least partially situation-adapted holding brake pressure determined becomes. The dependent on the road gradient pressure value is particularly preferably based on at least one brake actuation pressure and the vehicle deceleration achieved during stoppage determined. This has, as stated above, the advantage of cost-effective evaluation of already existing or easily determined sizes in the vehicle.

Prefers be the brake actuation pressure of the front wheel and the Brake actuation pressure of the rear wheel added up or weighted added to the summed brake actuation pressure to determine the holding brake pressure or the base value of the holding brake pressure. By a weighted sum of the brake actuation pressure front and rear wheels with different weighting coefficients is the different braking effect on the front and rear wheels considered.

Prefers is the holding brake pressure as the sum or weighted sum of Actuator brake pressures on the front and rear wheels increased selected by a predetermined value. The addition of a given Value reduces the risk of rolling away. Here is an actuating brake pressure the brake pressure applied at the moment of stopping the motorcycle or one over a given period of time stopping averaged brake pressure.

According to one preferred embodiment of the invention Procedure, the holding brake pressure only from the brake actuation pressures front and rear wheels necessary for stopping the motorcycle were, determined and / or a roadway slope based on at least a brake actuation pressure and during of stopping reached vehicle deceleration, if when stopping the motorcycle no brake control, such. Legs Anti-skid control, was performed. Only one unregulated braking is the reached delay in approximately proportional to the applied brake pressure and the gradient / the Slope of the roadway.

The Strength of the holding brake pressure, which in the context of the holding function is constructed and maintained, is preferred depending determined by the roadway inclination. This is a situation-appropriate Choice of the strength of the holding brake pressure given the Keeping the bike safely guaranteed, but also no unnecessary oversizing of the brake pressure entails. So a secure hold is also very steep Hanging securely.

The The invention also relates to an electronic brake system for a motorcycle in which a method according to at least one of claims 1 to 9 is performed.

Preferably, the inventive method is carried out in an integral brake system of a motorcycle, in which upon actuation of a brake actuator, z. B. the handbrake lever or the foot brake lever, in addition, an active brake pressure build-up on a wheel brake of the other brake circuit, which is not hydraulically connected to the actuated brake actuator, is carried out.

One Advantage of the invention lies in the improved security Hold on a slope. By the invention, the driver so that he can concentrate better on traffic. Another advantage of the invention lies in the situation-adapted Determination of the holding brake pressure. Independent of the driver operates a brake lever or both brake levers, or whether stopping in the plane or on a slope Gradient is performed, the holding brake pressure is so measure that the motorcycle is secured against rolling away.

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

It show schematically

1 a representation of a motorcycle on a slope,

2 a flowchart of a motorcycle driver assistance system with hold function, and

3 an exemplary relationship between vehicle deceleration and brake pressure for different roadway inclinations.

1 shows a schematic representation of an exemplary motorcycle on a slope. motorcycle 30 with control unit 31 and one wheel speed sensor each 32 on front wheel VR and rear wheel HR is on slope 33 , control unit 31 is designed for the control of the brake system and for the control of the execution of a holding function or stopping and starting function.

In 2 In the form of a schematic flow chart, an example of a method for preventing a vehicle from rolling away (holding function) is shown. In block 40 will check if motorcycle 30 resting or nearly resting. In block 41 it is checked whether an activation condition is met. If both conditions are fulfilled simultaneously or in quick succession, a holding brake pressure P _{MHG is first} built up in a wheel brake circuit, for example in the rear wheel brake circuit (block 42 ) and then hold this holding brake pressure P _MHG (approximately) (block 43 ).

It is therefore possible by an active pressure build-up, for. B. in the rear wheel, vehicle 30 on the mountain 33 safe to hold without the driver another brake operation on a brake actuator is necessary.

A resting or near resting of the motorcycle 30 (Block 40 ) is z. B. based on the signals of the wheel speed sensors 32 recognized. Is the wheel speed z. B. the rear wheel HR is smaller than a predetermined threshold, so is an (approaching) stoppage of the motorcycle 30 recognized. Instead of the wheel speed can also be another Raddrehgeschwindigkeitsgröße, which corresponds to the wheel speed used for standstill detection.

According to one example, the activation condition (block 41 ) actuation of a brake actuator, for. B. the handbrake lever. The activation of the active brake pressure build-up (holding brake pressure P _MHG ) thus takes place on the driver side via an actuation of a brake lever during or after recognized (approaching) standstill (block 40 ) of the motorcycle 30 ,

To activate the hold function, the driver actuates z. B. the front brake (handbrake lever) with a higher pressure than the pressure, which was needed to achieve the vehicle standstill. Then the system _builds up a sufficient pressure P _MHG in the rear wheel brake circuit (block 42 ) and then held (block 43 ) to the motorcycle on a slope 33 to keep. The pressure P _MHG remains constant even when the driver releases or partially releases the parking brake lever.

In order to determine the required holding pressure P _MHG according to an exemplary embodiment of the method according to the invention, the brake pressure applied to the front wheel P _VR and rear wheel P _HR by the driver for stopping the vehicle is detected over a certain predetermined period ΔT and the required holding pressure P _{MHG is} calculated therefrom. The period ΔT is specified vehicle-specific.

According to the example, the determination of the brake pressures P _VR and P _HR via a respective master cylinder pressure sensor in the brake circuit of the front wheel and in the brake circuit of the rear wheel.

P_MHG:

Haltebremsdruck,

P_VR, P_HR:

Bremsdrücke bzw. Hauptzylinder-Drücke an Vorderrad VR und Hinterrad HR während des Anhaltens (getrennt ermittelt), z. B. über einen vorgegebenen Zeitraum ΔT ermittelt, z. B. zeitlich gemittelt,

C1, C2:

Gewichtungsfaktoren bei der Berücksichtigung von Vorderrad- und Hinterradbremsdruck, und

A1:

additiver Druckwert.

By way of example, the holding pressure P _{MHG is} calculated using the following formula: P MHG [bar] = C1 · P VR + C2 · P MR + A1 (1) in which:

P _MHG :

Maintaining brake pressure,

P _VR , P _HR :

Brake pressures or master cylinder pressures on front wheel VR and rear wheel HR during stopping (determined separately), eg. B. determined over a predetermined period .DELTA.T, z. Time averaged,

C1, C2:

Weighting factors in consideration of front and rear brake pressure, and

A1:

additive pressure value.

Example are the weighting factors C1 = 1.5 and C2 = 1.0 and the additive value A1 = 2.

It is also another functional context and / or other values of the parameters (in the context of equation (1): weighting factors C1, C2 and additive pressure A1) possible, based on which / of the holding brake pressure P _MHG from the brake pressures P _VR and P _{HR is} determined.

A corresponding relationship with parameter values is for a specific motorcycle 30 z. B. in control unit 31 specified.

A holding pressure P _MHG determined according to equation (1) can be used to hold on a mountain 33 may not be sufficient with larger slope β. Either a subsequent sizing (increase) of the holding pressure P _MHG , after a vehicle movement (rolling away of the motorcycle 30 ), or it can be to safely avoid rolling away a larger offset value A1 to the determined stop pressure, z. B. according to equation (1) C1 · P _VR + C2 · P _HR , are added. However, the latter generally leads to an uncomfortable "sticking" of the motorcycle 30 when starting.

To the more precise, from the slope β of the mountain 33 dependent dimensioning of the holding pressure P _MHG is determined according to another embodiment of the method according to the invention the necessary holding pressure P _MHG as follows. It is the ratio (the relationship) between a stop applied brake pressure P and the achieved delay a used. The greater the slope β of the mountain 33 is, at which the driver stops, the greater is the delay a, which is achieved with (compared to the plane) the same applied brake pressure P.

The brake pressure P used to take account of the roadway inclination β may be the front wheel brake pressure P _VR or the rear wheel brake pressure P _HR already explained above or a weighted average between the two (P = d1 * P _VR + d2 * P _HR , with d1, d2: weighting factors).

The deceleration a is determined, for example (outside a controlled braking), from the wheel speeds (for example by numerical time derivative), which, for B. with the wheel speed sensors 32 be measured. It can for this purpose z. B. the vehicle reference speed determined in an antilock braking system can be used. Alternatively, the delay a can be obtained by suitable filtering from a wheel deceleration.

In 3 is an exemplary relationship between a braking pressure P applied to stop, the achieved deceleration a and the road gradient β shown schematically. For this purpose, the vehicle deceleration a is plotted as a function of the brake pressure P for various road inclinations β, characteristic 1 describes the relationship for the plane (β = 0 °), characteristic 2 for a slope of 10%, characteristic 3 for a slope of 20%, characteristic 4 for a slope of 30%.

So long it is not a regulated braking (eg braking with Anti-lock control), is the achieved delay a is approximately proportional to the applied pressure P and the slope / slope β of the roadway.

The relationship between the braking pressure P applied to stopping, the achieved deceleration a and the road inclination β is vehicle-dependent. It is measured at the factory and then in the form of a characteristic map or characteristic curves or a functional relationship in a control unit 31 stored. Based on the characteristic map or the characteristic curves or the functional relationship, the road inclination β is determined from a certain deceleration a and a certain brake pressure P.

In order to take account of the inclination β of the roadway, a slope-dependent value (offset) A (β) is added, for example, to a specific holding pressure basic value, which is determined from the stopping brake pressures P _VR and P _HR .

For example, in addition to or as an alternative to the additive pressure value A1, a slope-dependent value (offset) A (β) is added to the holding pressure (base value) determined according to equation (1) in order to obtain the holding brake pressure P _MHG .

For example, the base value is determined according to equation (1) with the parameters C1 = 1, C2 = 1 and A1 = 0. Thus, the holding brake pressure P _{MHG is} calculated from equation (2): P MHG [bar] = P VR + P MR + A (β) (2)

Will when stopping the vehicle 30 determined in the plane (β = 0 °) a stopping pressure of 10bar, this is sufficient in the plane to vehicle 30 to prevent it from rolling away. If a stop pressure of 10bar is also determined when stopping on a mountain with a 20% gradient, a holding pressure P _MHG of 10bar due to the downhill force will not be sufficient for the vehicle 30 to prevent it from rolling away. If, on the other hand, a pressure offset A (β) dependent on the gradient β is added to the determined stopping pressure, the vehicle can also be prevented from rolling away on the gradient at the same (initially) brake pressure applied by the driver.

An advantage of the method according to the invention is that the holding pressure P _MHG can be dimensioned as a function of the pitch β, ie, it does not have to be oversized in the plane. This leads to comfort improvements, since rolling does not have to be re-dimensioned and nevertheless "gluing" can be prevented during start-up in the plane.

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 [0003]
• - DE 3803563 A1 [0004]
• - DE 10316351 A1 [0004]
• - DE 102007025273 A1 [0006]

Claims (10)

Method for regulating the brake pressure in an electronically controlled braking system of a motorcycle ( 30 ), wherein in at least one wheel brake circuit, in particular in the rear wheel brake circuit, after a stopping or near stopping of the motorcycle by a driver, a holding brake pressure (P _MHG ) is established ( 42 ) and then maintained ( 43 ), which is a rolling away of the motorcycle ( 30 ), in particular without further actuation of a brake actuator by the driver, characterized in that the holding brake pressure (P _MHG ) from a brake actuation pressure (P _VR ) of the front wheel (VR) and a brake actuation pressure (P _HR ) of the rear wheel (HR) determined which is to stop the motorcycle ( 30 ) were necessary. A method according to claim 1, characterized in that the holding brake pressure (P _MHG ) is additionally determined as a function of a vehicle deceleration (a) achieved during stopping. Method according to Claim 1 or 2, characterized in that the holding brake pressure (P _MHG ) is determined as a function of the road inclination (β), which is determined by at least one brake actuation pressure (P _VR , P _HR ) and a vehicle deceleration (a) achieved during the stop. is determined. A method according to claim 3, characterized in that the road inclination (β) based on predetermined characteristics or a predetermined map or on the basis of a predetermined relationship, which / which / which / which is stored in particular in a control unit /, from the brake actuation pressure (P _VR , P _HR ) and the vehicle deceleration (a) is determined. Method according to at least one of claims 1 to 4, characterized in that at least one brake actuation pressure (P _VR , P _HR ) is determined by a pressure sensor which determines a master cylinder pressure, in particular that the brake actuation pressure (P _VR ) of the front wheel (VR) and the Brake actuation pressure (P _HR ) of the rear wheel (HR) is determined in each case by a pressure sensor which determines the master brake cylinder pressure of the respective wheel brake. Method according to at least one of claims 1 to 5, characterized in that the brake actuation pressure (P _VR ) of the front wheel (VR) and / or the brake actuation pressure (P _HR ) of the rear wheel (HR) than the brake actuation pressure present at the time of stopping or as an average of brake application pressures of the wheel over a predetermined time period (ΔT) during stoppage is determined. Method according to at least one of claims 1 to 6, characterized in that a base value of the holding brake pressure (P _MHG ) from the brake actuation pressure (P _VR ) of the front wheel (VR) and the brake actuation pressure (P _HR ) of the rear wheel (HR), which for stopping of the motorcycle were determined, and that to this base value of the road inclination (β) dependent pressure value (A (β)) is added, which in particular special basis of at least one brake actuation pressure (P _VR , P _HR ) and one during stopping reached vehicle deceleration (a) is determined. Method according to at least one of claims 1 to 7, characterized in that the holding brake pressure (P _MHG ) or the base value of the holding brake pressure as a, in particular weighted (C1, C2), sum of the brake actuation pressure (P _VR ) of the front wheel (VR) and the brake actuation pressure (P _HR ) of the rear wheel (HR) is determined. Method according to at least one of claims 1 to 8, characterized in that the holding brake pressure (P _MHG ) is determined only from the brake actuation pressure (P _VR ) of the front wheel (VR) and the brake actuation pressure (P _HR ) of the rear wheel (HR) to stop the motorcycle ( 30 ) were determined, and in particular in dependence on the vehicle deceleration achieved during stopping (a) is determined when at the stopping of the motorcycle ( 30 ) no brake control, in particular anti-skid control was performed. Electronic braking system for a motorcycle ( 30 ), characterized in that in this a method according to any one of claims 1 to 9 is performed.