DE102007027357A1 - Method for maneuvering a motor vehicle having a drive motor comprises driving the driving wheels via an automatic transmission and transferring a creep torque to the driving wheels - Google Patents

Abstract

Method for maneuvering a motor vehicle (100) having a drive motor (102) comprises driving the driving wheels (108hl, 108hr) via an automatic transmission (106) and transferring a creep torque to the driving wheels. The driving state of the vehicle is influenced by a actuator (124) to move the vehicle in the maneuvering direction with a prescribed speed. Independent claims are also included for the following: (1) Computer program product for carrying out the maneuvering method; and (2) Device for maneuvering a motor vehicle. Preferred Features: The vehicle is maneuvered from a resting state in which the vehicle is held by the driver by actuation of a brake.

Description

Technical area

The The invention relates to a method for maneuvering a motor vehicle wherein the motor vehicle comprises a drive motor with which at least one Drive wheel over an automatic transmission is drivable, and wherein by means of automatic transmission a creep torque to the drive wheel transferable is. The invention further relates to a for carrying out the Method suitable device.

Background of the invention

Due to the design or by a suitable clutch control can be automatic or operate automated transmissions in a creep mode, in a creep torque from the drive motor of a motor vehicle to which transmits to the drive wheels. The Creep allows the vehicle at a low speed to move without the driver an accelerator pedal for controlling the Actuate drive motor got to. The vehicle can thereby in particular in the implementation of maneuvering automatic be driven so that relieves the driver of the longitudinal guidance of the vehicle becomes.

So For example, by means of the creeping torque, the vehicle can automatically enter a parking lot be moved, the driver only the lateral guidance of the Make the vehicle based on steering movements and the vehicle first in the parking position must come to a halt. Under the name Parking assistant or parking aid systems are also known, which also support the driver in the transverse guidance of the vehicle. Such systems can steer the vehicle on a calculated path into a parking space or instruct the driver by providing steering recommendations To park the vehicle on a calculated track in a parking space. When using these systems, the driver can be even more on the monitoring concentrate the shunting and the vehicle only by a brake operation stop when it has reached the parking position or an obstacle gets too close.

in the With regard to a drive of the motor vehicle by that of the Gear transmitted creep torque However, there is the problem that this is often insufficient is great around the vehicle on a slope with a sufficiently high speed in uphill direction too move. In maneuvering, in which the vehicle is moved in downhill, there is also the problem that the vehicle by the downhill force on a Speed is accelerated, which is too high to ensure a safe Allow maneuvering.

Presentation of the invention

It is therefore an object of the present invention, the driver at maneuvering on a slope in the longitudinal guide of Support vehicle.

According to the invention this Task by a method having the features of the claim 1, a computer program product with the features of claim 15 and by a device having the features of claim 16 solved. embodiments The invention are set forth in claims 2 to 14.

• – anhand wenigstens eines Kriteriums festgestellt wird, dass das Kraftfahrzeug bei einem Antrieb durch das Kriechmoment nicht in einem Geschwindigkeitsbereich in eine Rangierrichtung bewegbar ist, und daraufhin
• – der Fahrzustand des Kraftfahrzeugs mittels eines auf die Längsdynamik des Kraftfahrzeugs Einfluss nehmenden Aktors beeinflusst wird, um das Kraftfahrzeug mit einer vorgegebenen Geschwindigkeit in die Rangierrichtung zu bewegen.

According to the invention, a method of the type mentioned is carried out so that

• - Is determined based on at least one criterion that the motor vehicle in a drive through the creep torque is not movable in a direction in a Rangierrichtung speed range, and then
• - The driving condition of the motor vehicle is influenced by means of an influence on the longitudinal dynamics of the motor vehicle acting actuator to move the motor vehicle at a predetermined speed in the maneuvering.

Further is a device for maneuvering a motor vehicle, wherein the motor vehicle comprises a drive motor with which at least a drive wheel over an automatic transmission is drivable, and wherein the automatic Transmission transmits a creeping torque to the drive wheel. The facility includes a rangeierassistenzsystem, which is adapted to at least a criterion that the motor vehicle at a Drive through a creeping moment not in a speed range is movable in a Rangierrichtung, and the driving condition of the vehicle due to the determination by means of one on the longitudinal dynamics of the motor vehicle influence influencing actor to the motor vehicle at a predetermined speed in the Move Rangierrichtung The speed range preferably includes a plurality of speeds, i. preferably has one upper limit different from a lower limit.

Advantageously, the invention provides that the vehicle can be driven solely by the creep, if this is possible due to the present gradient, ie, if the vehicle speed is not too small or too large. As a result, the vehicle moves in a maneuvering at a not too large gradient in the usual manner of the driver on the basis of the creep moments. With a larger gradient, the longitudinal dynamics are influenced by means of an actuator in such a way that the vehicle moves at a predetermined speed during the maneuvering operation.

hereby the driver is aware of the longitudinal guidance of the Relieves the vehicle, whereby the comfort for the driver is increased. In addition, the driver, as in the case of a slight slope, better focus on monitoring the movement of the vehicle.

at an embodiment of the method and the device is provided that the motor vehicle is ranged from a standstill, in which the motor vehicle due to an actuation of a brake by the Driver is held, and being determined by the criterion is that the motor vehicle after releasing the brake in a drive due to the creeping moment not in a speed range in a Rangierrichtung is movable.

In an embodiment the method and the device it is further provided that the Criterion fulfilled is when a present vehicle speed outside a predetermined speed interval and / or if the direction of movement of the motor vehicle from the Rangierrichtung is different.

Advantageous becomes in this embodiment Intervention in the longitudinal dynamics of the motor vehicle when the vehicle speed is not lies in a predetermined speed interval or the motor vehicle not moving in shunting direction. The verification of this criterion can in particular, after the driver releases the brake Vehicle has solved to set the vehicle in motion.

A another embodiment of the method and apparatus includes that an engine torque is requested by the drive motor when the present vehicle speed is less than a lower limit of the velocity interval and / or when the direction of movement of the motor vehicle from the Rangierrichtung is different.

If the present vehicle speed is lower than a lower one Limit of the speed interval is and / or if the direction of movement of the motor vehicle is different from the Rangierrichtung is assume that the motor vehicle on a slope in mountain climbing is to maneuver, and the creep torque is insufficient for a drive. Therefore, in such a situation, an engine torque becomes advantageous requested to move the vehicle. Thus, here is the Drive motor or a motor control as a the longitudinal dynamics the motor vehicle influencing actuator used.

Further shows an embodiment of the method and the device characterized in that a braking force by means of a power supply unit is set in a brake system when the present vehicle speed bigger than one upper limit of the speed interval is.

If the present vehicle speed is greater than an upper limit of the Speed interval, then it can be assumed that the motor vehicle on a slope is to be shunted downhill, and by the downhill power on one too big Speed is accelerated. Therefore, being beneficial in such a situation a braking force is set to lower the vehicle Decelerate speed. For this purpose, a power supply unit as one the longitudinal dynamics the motor vehicle influencing actuator used in it for example, a pressure source in a hydraulic brake system of the motor vehicle.

A Further development of the method and the device includes that meets the criterion is when a pitch angle of the motor vehicle outside a predetermined tilt angle interval.

This Criterion has the advantage that it already during the stoppage of the vehicle being checked can, since the pitch angle for example, by means of a longitudinal acceleration sensor in Standstill of the motor vehicle can be determined. This can be required Interventions in the longitudinal dynamics of the motor vehicle earlier initiated and carried out become.

Further the mass of the motor vehicle has an influence on whether the vehicle by means of the creeping moment on a gradient in a desired speed range can be moved.

Therefore sees an associated embodiment of the method and the device suggest that the limits of the pitch angle interval depend on be determined by a mass of the motor vehicle.

A embodiment of the method and the device is characterized in that an engine torque is requested from the drive motor when the Pitch angle of the motor vehicle outside the predetermined inclination angle interval is and the motor vehicle is inclined uphill in maneuvering.

Advantageous Thus, an engine torque is requested when the vehicle is uphill is to be ranked and the pitch angle of the slope is too large, so that the vehicle is not due to the creep with a desired Speed can be moved.

A another embodiment of the method and the device comprises a braking force adjusted by means of the power supply unit in the brake system is when the pitch angle of the motor vehicle outside the predetermined inclination angle interval is and the motor vehicle is inclined downhill in maneuvering.

Advantageous becomes in this embodiment a Braking force set when the vehicle is in downhill should be and the pitch angle of the slope is too large, so that the vehicle is accelerated too much by the downgrade force.

Further provides a development of the method and the device, that the requested engine torque or the set braking force in accordance with a deviation between a vehicle speed and the predetermined speed determined by means of a control device becomes.

Advantageous In this development, a control device for regulation the vehicle speed used to the engine torque or the Determine braking force.

A alternative embodiment of the method and the device is characterized in that the requested engine torque or the set Braking force depending from the pitch angle of the motor vehicle and / or the mass of the motor vehicle becomes.

Further is an embodiment of the method and the device thereby characterized in that one of the driver during the stoppage of the motor vehicle set braking force after releasing the brake at least partially is maintained and the driving condition of the vehicle after the Solve the Brake is affected after one by the driver of the motor vehicle output signal has been received.

at This configuration is only then intervened in the longitudinal dynamics and the vehicle is automatically set in motion when the driver gives a signal therefor has given. This will prevent the vehicle from moving the release the brake for unexpectedly sets the driver in motion. This one is special advantageous in a maneuvering in uphill direction, as the Driver due to the gradient possibly assumes that the vehicle is not moving and out of this Reason the brake releases. To keep the vehicle safe until the signal is delivered by the driver to be kept at a standstill, that of the driver during the Standstill set brake pressure at least partially upright receive.

Furthermore is in one embodiment the method and the device provided that the driving condition of the motor vehicle is only affected if a distance between the Motor vehicle and one in Rangierrichtung before the motor vehicle obstacle greater than one Threshold is.

hereby prevents the vehicle from being hit automatically, although there is an obstacle in front of the vehicle in the maneuvering direction, with which it could collide in case of a startup.

moreover provides an embodiment of the method and the device, that the Rangierrichtung from one of the driver of the motor vehicle determined on the gearbox of the motor vehicle selected gear becomes.

hereby can be easier and more reliable Way, in which direction the driver the vehicle wishes to rank.

Furthermore a computer program product is provided, the software code sections includes, with which a method according to one of the preceding Steps executable is when the software code sections are executed on a processor.

These and other aspects of the invention will become apparent from the embodiments and with regard to the embodiments below described with reference to the single figure.

Brief description of the figure

1 shows a schematic representation of a motor vehicle with a maneuvering assistance system.

Representation of embodiments

In 1 are a schematic representation of selected components of a four-wheeled vehicle 100 shown by way of example. The vehicle 100 has a drive motor 100 which is, for example, an internal combustion engine. From the driver, the drive motor by means of an accelerator pedal 104 controlled become. In the illustrated embodiment, the drive motor 100 via a gearbox 106 drivingly with the hinder wheels 108hr . 108hl of the vehicle 100 connected. Likewise, however, it may be provided that the drive motor 100 over the transmission 106 with the front wheels 108vr . 108vl of the motor vehicle 100 or with all motor vehicle wheels 108vr . 108vl . 108hr . 108hl connected is. In the transmission 106 In one embodiment, it is an automatic transmission having a torque converter, or an automated transmission having a clutch controlled by a clutch actuator. By means of a speed selector lever, not shown in the figure, the driver can select driving levels, each with a specific operating mode of the transmission 106 are linked. The driving stages include in particular a reverse gear and at least one forward stage, wherein the transmission 106 for a reverse drive, for example, provides a gear and for forward driving multiple gears, which are controlled by a transmission control. Furthermore, the gearbox has 106 about a creep mode, in which a creeping moment on the drive wheels of the vehicle 100 is transmitted without the driver pressing the accelerator pedal. In particular, a creeping torque can be transmitted to the drive wheels already during idling of the drive motor. In an automatic transmission with torque converter, it follows the transmission of the creep due to design, in an automated transmission, the clutch for transmitting the creep torque is brought by the transmission control in partial engagement. In addition, the transmission can be 106 lock by activating a parking lock. The parking brake can be activated by the driver using the gear selector lever.

The front wheels 108vr . 108vl of the vehicle 100 are designed steerable and over a steering column 110 with a steering handle 112 connected, which is for example a steering wheel. By operating the steering wheel 112 can the driver of the vehicle 100 the turning angle of the front wheels 108vr . 108vl change. In the steering column is also a steering actuator 114 used. In one embodiment, the steering actuator allows 114 a driver-independent change in the wheel angle of the front wheels 108vr . 108vl , In this embodiment, the steering actuator 114 for example, designed as a person skilled in the art known superposition steering.

In addition, the vehicle includes 100 a service brake system, which is designed in the illustrated embodiment as a hydraulic service brake system. From the driver, the service brake system by means of an actuator 116 be actuated, which is designed for example as a brake pedal. The brake pedal 116 is via a brake booster 118 , connected to a master cylinder. The master cylinder 120 is about Hydrauliklei lines, which for clarity in 1 not shown, fluidly with wheel brakes 122vr . 122vl . 122hr . 122hl connected to the wheels 108vr . 108vl . 108hr . 108hl of the vehicle 100 are arranged. Upon actuation of the brake pedal 116 becomes inside the master cylinder 120 a brake pressure within a brake fluid by means of the brake booster 118 built, via the hydraulic lines to the wheel brakes 122vr . 122vl . 122hr . 122hl can be transferred.

The service brake system also has an electronically controllable brake actuator, with the driver independently a brake pressure in the wheel brakes 122vr . 122vl . 122hr . 122hl can be adjusted. In one embodiment, the brake actuator may be a hydraulic unit 124 act between the master cylinder 120 and the wheel brakes 122vr . 122vl . 122hr . 122hl is switched. The hydraulic unit 124 is designed in a manner known to those skilled in the art and includes an arrangement of electrically switchable valves and a motor-driven pump for setting wheel-specific brake pressures. Likewise, the brake booster 118 be designed as a so-called active brake booster, in which a brake pressure by an electronically controllable actuator in the master cylinder 120 can be built. In this case, this actuator can be used as a brake actuator, and on the hydraulic unit 124 can be dispensed with.

The vehicle 100 also has an environment sensor. This includes at least on the vehicle front and around the rear of the vehicle 100 arranged distance sensors 126v 126h that blocks the distance to obstacles in the front and rear of the vehicle 100 to capture. In addition, the environment sensor preferably also contains in 1 not shown sensors for detecting obstacles in the lateral environment of the vehicle 100 and for determining the distance between the vehicle 100 and these obstacles. The sensors are embodied in a manner which is basically known to the person skilled in the art and can be designed, for example, as infrared, radar, lidar, ultrasound and / or camera sensors.

To assist the driver in maneuvering the vehicle points 100 a driver assistance system 128 comprising a shunting assistance system which controls the longitudinal dynamics of the vehicle 100 partially takes over during a maneuvering process. In an embodiment, the driver assistance system comprises 128 In addition, a parking assistance system, which the driver during a parking operation in the transverse guidance of the vehicle 100 supported. The maneuvering assistance system is signaled directly or via one or more control units with the drive motor 100 and the brake actuator connected. The parking assistant is signal-wise with the steering actuator 114 connected. Preferably, the driver assistance system is concerned 128 to a software, the control signals to control the drive motor 100 and the said actuators is generated and executed on a processor of a control unit.

By means of the parking assistance system, the vehicle 100 starting from a starting position in one around the vehicle 100 located parking space are ranked. The starting position is located near the parking space and is approached by the driver. It may be provided that the parking assistance system previously determined a suitable parking space between located on the side of the roadside objects, which are usually parked vehicles. For this purpose, the control unit evaluates the distance to objects in the lateral environment of the vehicle, for example, based on the distance signals supplied by the surroundings sensor 100 off while the vehicle is moving 100 controlled by the driver moves. If a suitable parking space has been determined, this is signaled to the driver by an acoustic and / or visual signal, so that the driver the vehicle 100 due to the signal after passing the detected parking space in the starting position for the parking operation can bring to a standstill. Preferably, the vehicle 100 backwards into the parking space, so that the parking space is behind the vehicle in the starting position 100 located. However, it may also be provided that the vehicle 100 is retracted forward into the parking space. In this case, the parking space is in front of the vehicle when it is in the starting position. The direction in which the vehicle 100 is moved, is also referred to as Rangierrichtung.

In the starting position, the vehicle 100 initially held by a brake actuation of the driver at a standstill. When the vehicle 100 is in the starting position, the parking assistance system checks whether the driver has set a driving direction corresponding to the intended driving direction. Should the vehicle 100 parked backwards, the parking assistance system thus checks whether the reverse gear is set. If parking in the forward direction is provided, the parking assistance system checks whether a forward drive is set. If the park assist system has detected the correct gear, parking is started after the driver depresses the brake pedal 116 has solved. The vehicle 100 then moves automatically into the parking space until an end position is reached. At the final position becomes the vehicle 100 stopped by the driver by operating the service brake. For this purpose, the driver by optical and / or acoustic signals on the distance between the vehicle 100 and informed the parking space in the direction of travel limiting object. According to this distance and by an assessment of the position of the vehicle 100 in the parking space, the driver can decide that the final position has been reached and the vehicle 100 stop.

The train on which the vehicle 100 is ranked in the parking space is calculated by the parking assistance system.

For this purpose, in particular, the relative position of the vehicle in the starting position is preferred 100 in relation to the parking space and the size of the parking space. The transverse guide of the vehicle 100 during the parking operation is carried out in one embodiment by the parking assistance system. For this purpose, the parking assistance system has a track sequence controller which, depending on the position of the vehicle, control signals for controlling the steering actuator 114 generated. The control signals are sent to the steering actuator 114 transmitted in accordance with the control signals the Radeinschlagwinkel the front wheels 108vr . 108vl established. Applicable track sequence controllers are known per se to those skilled in the art and will therefore not be explained further here.

To assist the driver in the longitudinal guidance of the motor vehicle, the maneuvering assistance system is used, which is capable of the brake actuator and the drive motor 100 or a control unit of the drive motor 100 head for. The maneuvering assistance system can be activated, for example, by the parking assistance system when the vehicle is moving 100 is located in the starting position and has been determined that the driver has chosen a Rangierrichtung corresponding speed step.

In one embodiment, the maneuvering assistance system checks for the driver-side release of the brake pedal 116 whether the vehicle is 100 at a speed which is within a predetermined speed interval, moved in the Rangierrichtung. For this purpose, a speed signal is used which can be determined, for example, from signals from wheel speed sensors. The speed interval includes the typical speeds at which the vehicle is moving 100 moved in the plane, if it is exclusively by that of the gearbox 106 transmitted creep torque is driven. The wheel speed sensors are designed to be direction-discriminating, so that to the speed signal, an addition, such as a sign, can be determined, from which the Bewegungsrich vehicle 100 can be determined. Alternatively, to determine the direction of movement of the vehicle 100 Measurement signals of a longitudinal acceleration sensor are used, which are when rolling up the vehicle 100 change in a direction from which the direction of movement can be determined. The fact that the driver releases the service brake becomes due to a pressure drop in the master cylinder 120 the service brake system found that can be determined from the signals of a pressure sensor.

If the result of the test is positive, ie if it is determined that the vehicle 100 moved at a speed below the threshold in the maneuvering, it is assumed that the vehicle 100 due to a drive through the gearbox 106 transmitted creeping torque moves in the Rangierrichtung. An intervention in the longitudinal guide is not made in this case by the maneuvering assistance system.

If the result of the test is negative, the maneuvering assistance system intervenes in the longitudinal guidance of the vehicle 100 in front. For this purpose, a control device is activated in a negative test result, which determines the longitudinal speed of the vehicle 100 adjusted to a predetermined target speed. If it is determined from the speed signal that the vehicle 100 moves at a speed that is less than the lower limit speed of the speed interval, or if the vehicle is determined to be 100 moves in a direction opposite to the maneuvering direction, it can be assumed that the vehicle 100 is located on a slope on which it must be moved uphill, and the crawling moment is insufficient to the vehicle 100 to set in motion. The control device therefore determines from the deviation between the vehicle speed and a predetermined uphill target speed, an engine torque request. The engine torque request is sent as a control signal to the drive motor 100 whose operating state is changed in accordance with the control signal to the vehicle 100 to move at the specified target speed. The uphill target speed corresponds to a speed with which the vehicle 100 is typically moved when driven on a flat road by the creep torque. Preferably, the uphill target speed is greater than the lower limit speed of the speed interval.

When the vehicle 100 moved at a speed above the upper limit of the given speed interval in the direction of shunting, then it is assumed that the vehicle 100 moved downhill on a slope and is accelerated by the downhill force on too high a speed. In this case, the controller determines a brake pressure request from a deviation between the vehicle speed and a predetermined downhill target speed. The downhill target speed may be equal to or different from the uphill target speed. The brake pressure request is sent as a control signal to the brake actuator, which then the brake pressure in the wheel brakes 122vr . 122vl . 122hr . 122hl changed in accordance with the brake pressure request.

To control the engine torque and the brake pressure, the control device preferably comprises an engine torque and a brake pressure regulator. In this case, a switching between the controllers is provided, which may be required if the pitch angle of the gradient changed during shunting. Thus, the engine torque controller switches to the brake pressure regulator when the vehicle speed increases, and the drive motor 100 of the vehicle 100 already idle. Switching from the brake pressure regulator to the engine torque regulator occurs when the vehicle speed decreases and a brake pressure of zero already exists in the wheel brakes 122vr . 122vl . 122hr . 122hl is set.

In particular, when maneuvering in uphill direction, it may happen that the vehicle due to the previously described control interventions in the vehicle longitudinal dynamics 100 rolls on, although the driver does not expect this due to the slope. Therefore, it may be provided that the brake pressure set by the driver during standstill is initially maintained by means of the brake actuator when the driver depresses the brake pedal 116 solves. A reduction of the brake pressure takes place only when the driver has given a start signal. The signal can be given for example by means of a switch. Likewise, it may be provided that an actuation of the accelerator pedal 104 is interpreted as such a starting signal, so that the vehicle 100 starts after the driver depresses the accelerator pedal 104 at least "touched". After receiving the start signal, the brake pressure is reduced in the manner described, checked whether the vehicle 100 at a speed which is within the predetermined speed interval, moved in the Rangierrichtung. Depending on the result of the test, the control device is then activated in the manner described above.

Another embodiment differs from that previously described by the way in which the control device or the engine torque controller or the brake pressure regulator is activated becomes. In this embodiment, an uncontrolled rolling of the vehicle 100 avoided after the driver-side release the service brake system. In this embodiment, the pitch angle of the vehicle 100 determined while it is in the home position at a standstill. To determine the longitudinal inclination angle, for example, a longitudinal acceleration sensor is used in a manner known to those skilled in the art, the signals of which are fed to the maneuvering assistance system. During the stoppage of the vehicle 100 applies to the pitch angle α sin (α) = a sensor / g (1) where a _{sensor is} the longitudinal acceleration measured by the sensor and g is the gravitational acceleration. Further, the mass of the vehicle 100 certainly. In principle, any method known to the person skilled in the art for determining the vehicle mass can be used for this purpose.

Taking into account the longitudinal inclination angle and the vehicle mass, the maneuvering assistance system then determines whether the vehicle is moving 100 located on a slope and interfering with the longitudinal dynamics of the vehicle 100 required are. In this case, preferably, the sign of the pitch angle is selected so that this indicates whether the vehicle 100 should be ranked uphill or downhill. In particular, the pitch angle can be provided with a positive sign when the vehicle 100 should be ranked uphill and with a negative sign when the vehicle 100 should be ranked downhill. Usually, however, the sign of the pitch angle indicates whether the vehicle 100 is oriented in uphill or downhill. Thus, the pitch angle according to equation 1 is positive or negative when the vehicle 100 is aligned in uphill or downhill. Therefore, the shunting assistant changes the sign of the pitch angle determined according to Equation 1 when the vehicle 100 is to be rearranged, that is, when a reverse gear is set.

While the vehicle 100 In the home position, the shunt assistant checks to see if the pitch angle is within a given pitch angle interval. The upper positive limit of the interval is determined as a function of the vehicle mass and corresponds to a gradient in which the vehicle 100 can still be moved by means of the creeping torque with a sufficiently high speed. The lower negative interval limit corresponds to a gradient at which the vehicle 100 can still be moved without braking intervention at a not too high speed and is also determined depending on the vehicle mass. The interval limits of the inclination angle interval are stored, for example, as a function of the vehicle mass in the maneuvering assistance system.

If it is determined that the determined pitch angle of the vehicle 100 is outside the interval, then the control device is activated as soon as the driver releases the brake or as soon as the brake pressure falls below a pressure threshold value during the driver-side release of the brake. The pressure threshold value can be determined as a function of the determined pitch angle and the vehicle mass. In particular, the pressure threshold value can be calculated so that it corresponds to a brake pressure, in which the braking force in terms of amount just the vehicle 100 acting downhill force corresponds.

In the case of a maneuvering in uphill direction, ie at a positive pitch angle, it may also be provided that an engine torque is already requested before the activation of the control device, which is sufficient to the vehicle 100 to stop or slightly accelerate without brake actuation at the present grade. Such engine torque corresponds to a drive force that is equal to or slightly greater than that on the vehicle 100 acting downhill force and can therefore be calculated from the determined pitch angle and the vehicle mass. To roll back the vehicle 100 To prevent this, it can also be provided that initially briefly, ie until the requested engine torque in the drive motor 100 has been adjusted, a brake pressure is maintained, which is sufficiently large to the vehicle 100 to keep at a standstill. In this case, the brake pressure set by the driver during standstill can be completely maintained, or the brake pressure can be maintained at the level of the previously described pressure threshold.

In addition, it may also be provided in this embodiment, that after releasing the brake by the Fah rer first to hold the vehicle 100 sufficient brake pressure is maintained. Here, the brake pressure in the set by the driver during standstill altitude or at the level of the aforementioned pressure threshold value can be maintained. A reduction of the brake pressure and optionally the above-described requirement of the engine torque and the activation of the control device take place only when the given by the driver start signal has been received, so that an unexpected rolling of the vehicle 100 is avoided.

If it is determined that the determined pitch angle of the vehicle 100 is above the upper limit of said pitch angle interval, ie, when the vehicle 100 is to be ranked in uphill position and it can be assumed that the creeping moment is insufficient for the vehicle 100 to drive, then the engine torque controller of the control device is activated. After activation, the engine torque is then adjusted by the engine torque controller in the manner already described to the vehicle 100 to move with the target speed. If the determined pitch angle is below the lower limit of the pitch angle interval, the brake pressure regulator is activated. This then regulates the brake pressure in the manner already described to the vehicle 100 to keep on the downhill target speed. Under the conditions described above can also be done switching between the engine torque and the brake pressure regulator.

In a further embodiment, a control device is used instead of the control device described above, which adjusts the uphill or downhill target speed using a control method. The controller is also activated when it is determined that the determined pitch angle of the vehicle 100 outside the pitch angle interval.

If the vehicle 100 is to be ranked uphill, ie, in the case of a positive pitch angle, the controller calculates an engine torque request from the present pitch angle of the vehicle 100 and the vehicle ground and sends them to the drive motor 100 or the engine control unit. The engine torque request is calculated so that the vehicle 100 due to the resulting driving force can move at a low speed in uphill. For this purpose, for example, a target speed can be specified and in a manner known to those skilled in a motor torque can be calculated, which is the amount of the sum of the on the vehicle 100 acting downgrade force and the rolling resistance present at this speed corresponds (the air resistance can be neglected due to the low speed).

In the case of a negative pitch angle, ie when the vehicle 100 is to be ranked downhill, the controller calculates a brake pressure request from the present pitch angle of the vehicle 100 and the vehicle mass and sends it to the brake actuator. The brake pressure requirement is calculated so that a braking force resulting from the request is dimensioned so that the vehicle 100 with a not too high speed moved in downhill. For this purpose, for example, in turn, a target speed can be specified and in a manner known to those skilled in a braking force can be calculated, which is the amount of the sum of the on the vehicle 100 acting downhill force and the rolling resistance present at this speed corresponds.

Provided the longitudinal acceleration angle while of the shunting process by more than a predetermined amount, takes place preferably a recalculation of the engine torque or the brake pressure. Preferably, the vehicle speed is also monitored and by a reduction of the engine torque or an increase of the Brake pressure limited to a maximum value, if this exceeded has been.

The Rangierassistenzeinrichtung disables the controller and terminates the engine torque or brake pressure request when the driver the vehicle 100 brought to a standstill again by operating the service brake system. In this case, the engine torque or brake pressure requirement can be reduced to zero to the extent that the brake pressure in the master cylinder is on the driver side 120 is increased.

When the vehicle 100 is at a standstill, then checks the Rangierassistzeinrichtung based on the distance signals of aligned in maneuvering distance sensors, whether the distance between the vehicle 100 and an object is less than a predetermined distance threshold.

If this is not the case, then the control device is reactivated in the manner previously described when the driver depresses the brake pedal 116 triggers, as it can be assumed that this has only interrupted the maneuvering process and would like to continue. Of course, the Rangierassistent can be disabled by the driver, for example by means of a switch. Likewise, the maneuvering assistance system is disabled, for example, when the driver a parking brake of the transmission 106 turns on or if he has a parking brake of the vehicle 100 actuated.

If during a stoppage of the vehicle 100 is determined that the distance to a in maneuvering in front of the vehicle 100 is less than the distance threshold, then the maneuvering assistance system checks to see if the driver is changing gears to set a driving gear in which the vehicle is traveling 100 is moved against the previous Rangierrichtung. If this is the case, then the control device in one of Re-enabled modes previously described. This is done on the assumption that the driver - when he is the vehicle 100 stops in front of an obstacle and the driving gear changes in the said way - the vehicle 100 away from the obstacle to improve the final position of the parking process. For example, when parking in a parking space, it is often observed that drivers drive their vehicle 100 presuppose after the vehicle 100 was moved very close to a parking space limiting obstacle. If the driver does not change the gear or a gear lock of the transmission 106 activated, then it can be assumed that the reached position coincides with the desired end position of the maneuvering operation by the driver. In this case, the maneuvering assistance system is deactivated.

The shunting assistance system shown above thus allows the vehicle 100 automatically move at a speed when the creep torque when maneuvering in uphill position is insufficient to make the vehicle 100 to drive in the desired manner, or if the vehicle 100 is accelerated too much by a downgrade force.

The Rangierassistenzsystem is previously in an interaction with a parking assistance system has been described. The integration of the maneuvering assistance system in a parking assistance system provides an advantageous application However, it is also possible, the Rangierassistenzsystem autonomous, i. especially independent operated by the parking assistance system. In this case, done instead of activation by the parking assistance system for example an activation by the driver of the vehicle, this one about can operate switch arranged in the interior of the vehicle. After activation checks the assistance system in this embodiment, then first, whether the distance between the vehicle and a front in shunting direction the vehicle is below a threshold. If this is the case, then the vehicle is not automatically through set the maneuvering assistance system in motion. Is located, however no obstacle in the direction in front of the vehicle or is the Distance to one in the Rangierrichtung located in front of the vehicle Obstacle greater than the threshold, the shunting system operates after activation in the manner described above.

Claims (16)

Method for maneuvering a motor vehicle ( 100 ) wherein the motor vehicle has a drive motor ( 102 ), with which at least one drive wheel ( 108hl . 108hr ) via an automatic transmission ( 106 ) is drivable, and wherein by means of the automatic transmission ( 106 ) a creep torque to the drive wheel ( 108hl . 108hr ), in which, on the basis of at least one criterion, it is established that the motor vehicle ( 100 ) in a drive through the creep torque is not movable in a Rangierrichtung in a speed range, and then - the driving condition of the motor vehicle ( 100 ) by means of an on the longitudinal dynamics of the motor vehicle ( 100 ) Influencing actor ( 102 ; 124 ) is influenced to the motor vehicle ( 100 ) to move at a predetermined speed in the Rangierrichtung. Method according to claim 1, wherein the motor vehicle ( 100 ) is ranged from a standstill, in which the motor vehicle ( 100 ) is maintained due to an operation of a brake by the driver, and it is determined by the criterion that the motor vehicle ( 100 ) is not movable in a Rangierrichtung in a speed range after releasing the brake in a drive through the creep torque. The method of claim 1 or 2, wherein the criterion is met, if a present vehicle speed is outside a predetermined speed interval and / or if the direction of movement of the motor vehicle ( 100 ) is different from the Rangierrichtung. The method of claim 3, wherein an engine torque from the drive motor ( 102 ) is requested if the present vehicle speed is less than a lower limit of the speed interval and / or if the direction of movement of the motor vehicle ( 102 ) is different from the Rangierrichtung. A method according to claim 3 or 4, wherein a braking force by means of a power supply unit ( 124 ) is set in a brake system when the present vehicle speed is greater than an upper limit of the speed interval. Method according to one of the preceding claims, wherein the criterion is fulfilled when a longitudinal inclination angle of the motor vehicle ( 100 ) is outside a predetermined tilt angle interval. Method according to claim 6, wherein the limits of the inclination angle interval depend on a mass of the motor vehicle ( 100 ). The method of claim 6 or 7, wherein a Motor torque from the drive motor ( 102 ) is requested when the pitch angle of the motor vehicle ( 100 ) is outside the predetermined inclination angle interval and the motor vehicle is inclined uphill in maneuvering. Method according to one of claims 6 to 8, wherein a braking force by means of the power supply unit ( 124 ) is adjusted in the brake system, when the longitudinal inclination angle of the motor vehicle ( 100 ) is outside the predetermined inclination angle interval and the motor vehicle ( 100 ) is inclined downhill in maneuvering. Method according to one of the preceding claims, wherein the requested engine torque or the set braking force proviso a deviation between a vehicle speed and the predetermined speed determined by means of a control device becomes. Method according to one of the preceding claims, wherein the requested engine torque or the set braking force as a function of the pitch angle of the motor vehicle ( 100 ) and / or the mass of the motor vehicle ( 100 ) is calculated. Method according to one of the preceding claims, wherein one of the driver during the stoppage of the motor vehicle ( 100 ) set braking force is at least partially maintained after release of the brake and the driving condition of the motor vehicle ( 100 ) is affected after release of the brake, after one of the driver of the motor vehicle ( 100 ) signal has been received. Method according to one of the preceding claims, wherein the driving state of the motor vehicle ( 100 ) is only affected if a distance between the motor vehicle and an obstacle located in the direction in front of the motor vehicle is greater than a threshold value. Method according to one of the preceding claims, wherein the shunting direction from one of the driver of the motor vehicle ( 100 ) on the transmission ( 106 ) of the motor vehicle set driving level is determined. Computer program product comprising software code sections, with which a method according to any one of the preceding claims is executable, when the software code sections are executed on a processor. Device for maneuvering a motor vehicle ( 100 ), wherein the motor vehicle ( 100 ) a drive motor ( 102 ), with which at least one drive wheel ( 108vl ; 108vr ) via an automatic transmission ( 106 ), and wherein the automatic transmission ( 106 ) a creep torque to the drive wheel ( 108vl ; 108vr ), comprising a Rangeierassistenzsystem, which is adapted to determine based on at least one criterion that the motor vehicle ( 100 ) is not movable in a Rangierrichtung in a speed range in a driving direction by a creep torque, and the driving condition of the vehicle due to the determination by means of a on the longitudinal dynamics of the motor vehicle ( 100 ) Influence influencing actuator to the motor vehicle ( 100 ) to move at a predetermined speed in the Rangierrichtung.