DE102008026530A1 - Method for detecting and executing start-up process of motor vehicle, involves predetermining connection in form of function, characteristic line or set of characteristic curves, particularly factory installed - Google Patents

Abstract

The method involves predetermining a connection in form of a function, a characteristic line or a set of characteristic curves, particularly factory installed, and is stored in a storage unit, particularly a control device in a vehicle. An engine torque, an engine speed or the temporary gradients of an engine speed, a throttle-valve angle or the temporary gradients of throttle-valve angle are provided in the method. An independent claim is included for a device for detecting and executing a start-up process of a motor vehicle or for controlling a braking system of a motor vehicle.

Description

The The invention relates to a method according to the preamble of claim 1 and a device according to the preamble of claim 13.

vehicle systems to assist a driver with a hold and / or Starting process, which the vehicle at a standstill, z. B. at one Hang, hold and allow the driver to start, are for the comfort and safety of the vehicle occupants / Vehicle driver of great importance. So will by such systems the driver of the actuation of Brake released during stopping and when starting and the driver can concentrate better on the traffic. Advantageously, the desire of the driver to start from the Vehicle system detected automatically. If it is recognized as a start-up request the brake pressures in the vehicle brake system are changed automatically to ensure a comfortable start-up process.

In the field of passenger cars, methods for starting detection and starting assistance are known, for. B. from the DE 103 06 363 A1 which inter alia evaluate information about the clutch actuation and the current value of the engine torque. In order to detect whether a valid start-up request is present, the information is required as to whether there is adhesion between the engine and the drive train and whether the driver would like to be able to move the vehicle from standstill by increasing the engine torque. For this purpose, the signals available in the vehicle of the clutch and the gear information and the engine torque are used.

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. So are increasingly equipped motorcycles with electronic braking systems, such as anti-lock braking system (such as from the EP 0 548 985 B1 known) or integral brake system (such as from DE 38 03 563 A1 and DE 103 16 351 A1 known), which may also include driver assistance systems with stop and start function. An electronically controlled braking system with stopping and starting function for a motorcycle is used in the DE 10 2007 025 273 A1 described.

at some vehicle types, eg. B. on most motorcycles, are information about the operation of the clutch not available or is this information not available. Also a reliable information about the engine torque is often, for. B. the motorcycle, not in the brake control unit available, for. B. due to the lower crosslinking the various control devices. A start detection and / or Start-up assistance based on information about the clutch actuation and the engine torque as described above is therefore not possible in such systems.

Of the Invention is therefore the object of a method and a Device for detecting and / or imple tion of a startup of a motor vehicle with which / which the initiation of the start-up by the driver reliable recognized and / or the brake pressure when starting properly controlled will, even if no direct information about the current Engine torque and / or the coupling state available stands.

These The object is achieved by the method according to claim 1 and the device according to claim 13 solved.

Of the Invention is based on the idea, based on at least one of both vehicle sizes engine speed and throttle angle and at least one predetermined relationship, which dependency of the two sizes with each other or dependence a motor torque of at least one of the two sizes describes a recognition of the start-up will and / or a scheme To perform the braking force when starting, the context in the form of a function, a characteristic or a characteristic field is fixed. Alternatively or in addition to consideration The vehicle size (s) itself can also be the temporal Gradient (the time derivative) of the respective vehicle size to be viewed as.

According to one preferred embodiment of the invention Procedure gives the given context the dependence the engine torque from the engine speed and / or the throttle angle again. As in vehicles usually at least one the two variables engine speed and throttle angle can be so available with the help of context Motor torque can be determined indirectly. Particularly preferred the engine torque from the engine speed and the throttle angle certainly.

The certain engine torque is then available for evaluation, preferred for Anfahrerkennung and / or Anfahrunterstützung and / or regulation of the braking force, but also for others Regulation / control systems. Particularly preferred is the particular engine torque used to control the braking force during startup.

According to one Another preferred embodiment of the invention Method is alternatively or additionally the context between the engine speed at idle and the throttle angle and / or the relationship between the temporal gradient of Engine speed at idle and the throttle angle specified. Based on this specification is particularly preferred by comparison with the current engine speed and / or the current time gradient the engine speed (at a current throttle angle) closed a clutch state and / or a start request of the driver.

It It is also preferred that the temporal gradient of the engine speed idle depending on the throttle angle and the temporal gradient of the throttle angle predetermined is. As a result, the time course of the operation a throttle by the driver, which in the temporal Gradients of the throttle angle reflects considered become.

Prefers the procedure is carried out in a motorcycle or Preferably, the device is in a motorcycle because because the risk of tipping over just in a force wheel despite the unavailable Information about engine torque and clutch state one the most accurate detection of the driver's starting intention and / or the most accurate control of the braking force important when starting up.

Of the given context is preferred either theoretically or based on measurement data for the present vehicle or determined the type of vehicle present and factory or by a workshop stored in a control unit of the vehicle. Because the Evaluation of the given context for detection and / or Carrying out a startup of the motor vehicle is performed, which advantageously made in a part of the brake system is the relationship is particularly preferred in the brake control unit stored.

According to one Further development of the invention, a starting process is detected when the current engine speed compared to that for the current throttle angle according to the given Context expected engine speed changed at idle is, and / or if the current time gradient of the engine speed compared to that for the current throttle angle (and possibly its temporal gradient) according to the predetermined temporal gradient of the Engine speed at idle is changed. So can without knowledge of the engine torque and the clutch state, a start request of Driver can be reliably detected.

Of the Starting process is preferably detected when at standstill or near-stop of the vehicle, the current engine speed and / or the current time gradient of the engine speed respectively by more than a predetermined threshold is less than the expected according to the given context corresponding size at idle. The respective ones Thresholds are particularly preferably vehicle or vehicle type specific determined and filed with the given context.

The Regulation of the braking force is preferably carried out in such a way that a vehicle acceleration, which from a downhill torque and a braking torque and either the engine torque or a determined from the engine torque wheel torque is smaller is a limit. As a result, a jerk-free approach is achieved.

A downgrade torque, which is used to control the braking force during startup, is preferably determined from a specific or measured by a sensor roadway inclination. By taking into account the Hangabtriebsmomentes a situation-appropriate dosage of the braking force is possible, which z. B. rolling away of the vehicle is prevented. Particularly preferably, the roadway inclination angle is determined based on information from the last performed deceleration or braking operation to standstill of the vehicle. This information is very particularly preferably values of at least two of the following variables: the vehicle speed, the engine speed, the braking torque, the wheel rotational speed of a driven wheel and the engine torque, the engine torque being determined on the basis of the predetermined relationship. Advantageously, all these variables are used to determine the roadway inclination in order to obtain the most accurate roadway inclination angle. This is particularly advantageous in the case when no sensor for measuring the driving track inclination is present.

Prefers is the wheel torque, which is used to control the braking force when starting is used, as a product of the engine torque and a given characteristic value, which of the translation of the Gear depends and is given, calculated. So are no knowledge about the current state of transmission necessary.

According to one Further development of the invention is predefined with which a braking torque is determined from a brake pressure. In this case, the brake pressure is particularly preferably by a pressure sensor measured as brake pressure sensors in the context of anti-lock braking systems often already present in the vehicle.

According to one preferred embodiment of the invention Procedure, the control of the braking force when starting in Dependence on the roadway inclination, which is based on Information from the most recent deceleration process or braking is determined until the vehicle is at a standstill. Particularly preferred for determining the road inclination Energy considered during braking.

The The invention also relates to a device for implementation a method according to the invention.

One Advantage of the invention lies in a reliable automatic Abfahrerkennung and / or in a brake pressure control for smooth Start, with the appropriate control unit, z. B. of Braking system, no direct information about the engine torque and / or the coupling state. Also owns the invention has the advantage that it is realized inexpensively can be because the inventive method essentially based on the evaluation of existing signals, so that no further sensors o. Ä. Are necessary. to Realization of the method according to the invention On the vehicle side, there is only storage space and processor power necessary, which z. B. in the context of an existing brake control unit can be provided inexpensively and easily.

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

It show schematically

1 an example relationship between engine speed and throttle angle for different engine torques,

2 an example relationship between engine torque and engine speed at different throttle angles, and

3 exemplary time profiles of an engine speed and a throttle angle when holding and starting a motor vehicle.

When starting, the driver operates the throttle (or accelerator pedal). The throttle angle α and the engine speed N are increased. The self-adjusting engine speed N depends on the throttle angle α (given by the driver by the operation of the throttle lever) and the load of the engine (engine torque M) or, in other words, the engine torque M depends on the throttle angle α and the engine speed N. , The corresponding relationships can be represented by functions or characteristics. So z. B. the engine speed N according to a function h of the throttle valve angle α and the engine torque M dependent (see also 1 ) or the engine torque M is dependent on a function f of the throttle valve angle α and the engine speed N (see also 2 ): N = h (α, M) or M = f (α, N) (1)

In 1 an exemplary relationship h between engine speed N and throttle angle α for different engine torques M is shown. For four specified engine torques M (line 1 : M = 10 Nm; line 2 : M = 30 Nm; line 3 : M = 50 Nm; line 4 : M = 80 Nm), the engine speed N is plotted against the throttle angle α. line 5 at α = 30 ° illustrates that for fixed throttle angle α, the engine speed N at load increase (larger engine torque M) decreases.

In 2 an exemplary relationship f between engine torque M and engine speed N for different throttle angle α is shown. For five preset throttle angle α (line 10 : α = 0 °; line 11 : α = 15 °; line 12 : α = 20 °; line 13 : α = 22.5 °; line 14 : α = 25 °) engine torque M is plotted against the engine speed N.

Of the vehicle-specific relationship between engine torque M, throttle angle α and Engine speed N, which z. B. by a relationship h or f, z. B. in the form of a function or a characteristic field shown can be theoretically determined or empirically, for. B. based of measurements. The connection is then in one Control unit, which for the Anfahrerkennung and / or responsible for carrying out a start-up procedure is, for. B. a brake control unit stored.

is a relationship according to equation (1) is known, From this, other (functional) relationships can be derived between these quantities and their time derivatives determine, for. B. between the (temporal) gradient of the engine speed dN / dt, the throttle angle α, the (temporal) gradient the throttle angle dα / dt and the load of the engine (Engine torque M). Alternatively, other contexts between these quantities and their time derivatives can also be determined directly from measurements.

For example, the (time) gradient of the engine speed dN / dt can be represented as a function of the throttle angle α, the (temporal) gradient of the throttle angle dα / dt and the load of the engine (engine torque M), ie the (temporal) gradient The engine speed dN / dt is dependent on the throttle angle α, the (temporal) gradient of the throttle angle dα / dt and the load of the engine (engine torque M) according to a function y: dN / dt = y (α, dα / dt, M) (2)

These Dependence can, as mentioned above, theoretically or empirically determined for the vehicle, and will then stored in the controller.

On the basis of at least one of the (predefined) dependencies (For example, equation (1) and / or (2)) it is recognized whether the driver the Clutch has activated. Enlarged at the time of engagement the engine load, and the engine speed (the gradient of Engine speed) changes significantly.

In 3 are exemplary temporal courses of an engine speed N (line 20 ) and a throttle angle α (line 21 ) when holding and starting a motor vehicle shown schematically. At the time t _A , the driver operates the throttle and the throttle angle α increases. At time t _K, the driver engages.

By way of example, the following method is proposed. In the disengaged state (t <t _K ), the load on the engine is very low (engine torque at idle: M ₀ , depending on the vehicle, only due to friction losses). Therefore, the engine speed N (line 20 ) and / or dN / dt at a magnification of α (line 21 ) and / or dα / dt very strongly. This is in 3 in the period from time t _A to time t _K to see. When an engagement (time t _K ), the load on the engine increases significantly. This leads to a change in the gradient of the engine speed dN / dt or to a change in the dependence of the gradient of the engine speed on the throttle angle and gradient of the throttle angle dN / dt (α, dα / dt). For example, reduces the engine speed N at Lastver magnification (larger engine torque M) when the throttle angle α does not change (compare line 5 in 1 ) or even enlarged (see 22 in 3 after coupling at t _K ). This change in the dependencies N (α) and / or dN / dt (or dN / dt (α, dα / dt)) is used as a recognition feature for a start-up request (engagement).

On the basis of the stored context / relationships, the corresponding size at idle the vehicle is known. For example, the gradient of the engine speed dN ₀ / dt or the dependence of the gradient of the engine speed on the throttle angle and the gradient of the throttle angle dN ₀ / dt (α, dα / dt) and / or the engine speed as a function of the throttle angle N ₀ (α) stored for the vehicle in idle (this corresponds to equation (1) or (2) for M = M ₀ : N = N ₀ (α) = h (α, M ₀ ) or dN / dt = dN ₀ / dt (α, dα / dt) = y (α, dα / dt, M ₀ )). A (current) value of the gradient dN / dt and / or the engine speed N is measured during standstill.

An engagement is detected, for example, if the (current) value dN / dt becomes smaller than that hand of the stored relationship expected value dN ₀ / dt at idle: dN / dt <dN 0 / dt - S 2 (3a) and / or the value N becomes smaller than the expected value N ₀ at idle on the basis of the stored relationship: N <N 0 - p 1 (3b) where S ₁ and S _{2 are} predetermined threshold values.

After a journey recognition, z. B. by a method described above or by another, z. B. known from the prior art, method for approach recognition, the brake pressures P must be controlled according to the wheel torque M _W , so a jerk-free approach is possible. For a smooth start without rolling back, the following relationship between the relevant moments applies: M br <M W - M I (4) where M _{Br is} the braking torque and M _{I is} the downhill torque resulting from the slope of the road. M _I is positive if the road gradient is positive and negative if the gradient is negative.

The braking torque M _Br is over the, z. B. hydraulic, pressure P calculated in the brake system. To determine the pressure P, z. B. used in the electronic brake system existing pressure sensors. Another determination of the brake pressure P is also possible.

The braking torque M _Br is a function F of the brake pressure P in the corresponding brake circuit: M br = F (P) (5)

The function F is vehicle specific. It is determined theoretically or empirically, and z. B. stored in the brake control unit. From a determined brake pressure P and the stored function F, the braking torque M _Br can then be determined.

The wheel torque M _W is dependent on the engine torque M and the gear ratio G during a starting process. The corresponding functional relationship is named MW: M W = MW (M, G) (6)

The engine torque M is, as already described above, on the throttle valve angle α and the engine speed N depends (see 2 and compare equation (1)): M = f (α, N) (7)

The Dependence f is determined theoretically or empirically and is z. B. stored in a control unit. Based the dependence f the engine torque M is calculated if the engine speed N and the throttle angle α known are.

Then the wheel torque M _{W is} calculated from the engine torque M, z. B. according to M W = KG · M (8) where KG is a constant and depends on the ratio of the gear G. An approach is usually carried out in first gear or a translation can be assumed as a constant number. In some vehicles, the information on the current translation G is also in the controller, and in this case, the constant KG can be selected according to the current translation G.

wobei

V_t1:

Fahrzeuggeschwindigkeit beim Anfang des Bremsens zum Zeitpunkt t1,

V_t2:

Fahrzeuggeschwindigkeit beim Ende des Bremsens zum Zeitpunkt t2,

ω:

Winkelgeschwindigkeit eines Antriebsrades (z. B. mittels eines Drehzahlsensors eines Antiblockiersystems (ABS) gemessen,

E_I:

Steigungsenergie des Fahrzeugs, und

C1, C2, C3:

empirische Konstanten

sind.The downgrade torque M _I is z. B. calculated on the basis of the history of the transition to a standstill. For example, the downgrade torque M _{I is} calculated on the basis of an energy balance. When braking, the vehicle energy is converted into braking energy. When the vehicle speed V is small is, the following equation applies:

in which

V _t1 :

Vehicle speed at the beginning of braking at time t1,

V _t2 :

Vehicle speed at the end of braking at time t2,

ω:

Angular velocity of a drive wheel (eg measured by means of a speed sensor of an anti-lock braking system (ABS),

E _I :

Slope energy of the vehicle, and

C1, C2, C3:

empirical constants

are.

On the other hand, the slope energy E _{I is given} by the product of mass m of the vehicle, gravitational acceleration g and overcome height difference H: e I = m · g · H (10)

At the beginning of braking, vehicle speed V _{t1 is} stored and the two integrals from equation (9) are calculated until the end of braking. In addition, the braking distance S is calculated from the vehicle speed V (the time course of the vehicle speed V (t)):

When the vehicle comes to a standstill, E _{I is} calculated according to the following equation:

Equations (10) and (11) are used to calculate the road inclination β: H = E I / (m · g) (13) sin (β) = S / H (14)

The downhill torque M _I is proportional to the road inclination β: M I = C4 · sin (β) (15) where C4 is approximately a constant (motor vehicle specific). C4 is determined empirically or theoretically and stored in a control unit or the like.

Alternatively or additionally, it is also possible that the road inclination β is determined by means of a sensor, and from this the slope output torque M _{I is} calculated according to equation (15).

For a smooth starting process, the vehicle acceleration a must be limited. The vehicle acceleration a is dependent on the difference of the moments M _W - M _Br - M _I : a = C5 · (M W - M br - M I ) (16) where C5 is approximately a constant which is determined empirically or theoretically and z. B. is stored in a control unit. From the specific moments M _W and M _I (exemplary procedures for determining the two moments M _W and M _I were described above) and with the current value of the controlled braking torque M _Br so the current vehicle acceleration a is calculated.

The driver activates the clutch and the throttle / accelerator pedal. Throttle angle α and Mo Torsdrehzahl N are determined and determined wheel torque M _W. Downhill torque M _I is z. On the basis of the history (eg as indicated in equations (9) to (15)) or from the slope angle β determined by means of a sensor (via equation (15)). The pressure P in the brake system and a corresponding braking torque M _Br are regulated, so that the vehicle acceleration a increases uniformly and a start-up operation works smoothly. For this purpose, it is advantageous if the brake pressure P, and thus the braking torque M _Br , is controlled such that the vehicle acceleration a is always smaller than a limit value a ₀ : a <a 0 (17)

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

• - DE 10306363 A1 [0003]
• - EP 0548985 B1 [0004]
• - DE 3803563 A1 [0004]
• - DE 10316351 A1 [0004]
• - DE 102007025273 A1 [0004]

Claims (13)

Method with which by means of an evaluation of an engine speed (N) and / or a throttle angle (α) a starting operation of a motor vehicle, in particular a motorcycle, is detected and / or performed, wherein in the vehicle in at least one operating situation, a braking force on at least one wheel is held the vehicle and upon detection of a starting intention of the driver, the held braking force for performing a startup process is reduced, characterized in that for detecting the Anfahrwillens and / or for controlling the braking force when starting at least one predetermined relationship (y, f, h, N ₀ (α), dN ₀ / dt (α, dα / dt)) between at least two of the following quantities: - an engine torque (M), - an engine speed (N) or the time gradient of an engine speed (dN / dt) , - a throttle angle (α) or the temporal gradient of a throttle angle (dα / dt), the relationship in the form of a Function, a characteristic curve or a characteristic field, in particular the factory, given and stored in the motor vehicle in a storage means, in particular a control device. A method according to claim 1, characterized in that the at least one predetermined relationship (y, f, h, N ₀ (α), dN ₀ / dt (α, dα / dt)) theoretically or based on measurement data for the vehicle or the vehicle type is determined and stored in a control unit, in particular a brake control unit, factory or by a workshop. A method according to claim 1 or 2, characterized in that for detecting the starting operation at least - a relationship (N ₀ (α)) between the engine speed at idle (N ₀ ) and the throttle valve angle (α), and / or - a relationship (dN ₀ / dt (α, dα / dt)) between the time gradient of the engine speed at idle (dN ₀ / dt) and the throttle angle (α) is predetermined. A method according to claim 3, characterized in that the predetermined relationship, in particular the relationship (dN ₀ / dt (α, dα / dt)) between the time gradient of the engine speed at idle (dN ₀ / dt) and the throttle angle (α), additionally includes the dependence on the temporal gradient of the throttle angle (dα / dt). A method according to claim 3 or 4, characterized in that the starting operation is detected when - the current engine speed (N) is changed compared to the predicted according to the predetermined relationship (N ₀ (α)) engine speed at idle (N ₀ ), and / or - the current temporal gradient of the engine speed (dN / dt) compared to the expected according to the predetermined relationship (dN ₀ / dt (α, dα / dt)) temporal gradient of the engine speed at idle (dN ₀ / dt) changed is. Method according to at least one of claims 3 to 5, characterized in that the starting process is detected, when at standstill or approximately stoppage of the vehicle - the current engine speed (N) by more than a predetermined first threshold value (S ₁ ) is lower than that according to expected engine speed at idle (N ₀ ), and / or - the current time gradient of the engine speed (dN / dt) is lower by more than a predetermined second threshold (S ₂ ) than the time gradient expected according to the predetermined relationship Engine speed at idle (dN ₀ / dt). Method according to at least one of the claims 1 to 6, characterized in that for controlling the braking force when starting a motor torque (M), which is based on the given Connection (f), in particular from the engine speed (N) and the Throttle angle (α), is determined, is used. A method according to claim 7, characterized in that the control of the braking force is performed such that a vehicle acceleration (a), which - a downhill torque (M _I ) and - a braking torque (M _Br ) and - The motor torque (M) or one of the engine torque (M) determined wheel torque (M _W ) is determined, is smaller than a limit value (a ₀ ). A method according to claim 7 or 8, characterized in that for controlling the braking force when starting next to the engine torque (M) a downgrade torque (M _I ) is used, which is determined from a specific or measured by a sensor roadway inclination (β). Method according to claim 9, characterized that the roadway inclination (β) based on information from the last performed braking or braking operation until the vehicle is stopped. Method according to at least one of claims 7 to 10, characterized in that based on the engine torque (M) and a predetermined characteristic value (KG) a wheel torque (M _W ) is determined, which is used to control the braking force. Method according to at least one of Claims 1 to 11, characterized in that a braking torque (M _br ) adjusted in the regulation of the braking force is determined on the basis of a further predetermined relationship (F) from a brake pressure (P) determined in particular by a pressure sensor. Device for detection and / or implementation a startup process of a motor vehicle and / or the controller a brake system of a motor vehicle, wherein the motor vehicle in particular a motorcycle, with at least one means of determination a throttle angle (α) and / or an engine speed (N), a control and / or evaluation means and a storage means, characterized in that in this a method according to at least one of claims 1 to 12 is performed.