GB2481535A - Parking system using open/closed loop control activated by accelerator operation - Google Patents

Abstract

A semi-automatic parking control system of a motor vehicle 1 comprises process steps including using a parking space gauging system 4 and sensors 11 to gauge a parking space. A control system 6 calculates a trajectory (3, fig 4) and an automatic parking manoeuvre for traversing the trajectory is activated by operation of an accelerator pedal. An open and/or a closed loop control device 7 controls, during activation of the accelerator pedal and providing the vehicle 1 does not exceed a certain speed, the vehicle 1 into the parking space. If the accelerator pedal is released the open/closed loop control device 7 initiates a defined reduction of a speed of the vehicle 1 until the vehicle 1 comes to a standstill. The speed reduction is determined as a function of current speed and as a function of a position (5, 8) of the motor vehicle 1 along the trajectory (3). The parking system also comprises an electric wheel drive 17 and an electric steering drive 18 which sets a steering angle β of the driven wheels 2.

Description

Description

Process for semi-automatic parking of a motor vehicle and also a parking system The invention relates to a process for automatic open-loop and/or closed-loop control of a motion of a motor vehicle by a parking system in the course of a parking manoeuvre of the motor vehicle. The invention further relates to a parking system for a motor vehicle, exhibiting a parking-space gauging system, a control unit for calculating a trajectory on the basis of ascertained data of the parking-space gauging system, an electric wheel drive which enables a forward motion and reverse motion of the driven wheels, and also an electric steering drive for setting the steering angle of the driven wheels.

In parking systems for motor vehicles so-called semi-automatic parking systems are currently the state of the art and are cortunercially available in many vehicle models.

With these systems, the location and orientation of the parking space relative to the vehicle are determined when driving past a parking space by means of ultrasound sensors fitted laterally to the motor vehicle. Subsequently a suitable parking trajectory into the parking space is calculated. Once the parking manoeuvre has been started, a parking-assistance control unit drives the steering assembly of the vehicle, mostly an electric power steering (EPS), in such a way that during the rolling of the motor vehicle the steering wheel of the motor vehicle turns on its own -that is to say, without actuation by the driver -in such a way that the motor vehicle is steered into the parking space. That is to say, the parking-assistance control unit undertakes the transverse guidance of the vehicle. During the parking manoeuvre the driver still has to actuate the accelerator pedal and the brake, where appropriate alternatively or additionally, the clutch, in order in this way to stop the motor vehicle in time or to accelerate it. That is to say, the driver has to undertake the longitudinal guidance of the vehicle himself/herself.

In a further step of expansion, still currently at the development stage, the parking-assistance control unit also undertakes the longitudinal guidance of the motor vehicle 1 and stops the motor vehicle 1 automatically upon reaching the parking-space limits 19 between two parked motor vehicles 20, 21; see Fig. 1. In this case the driver still has to actuate the pedals of the motor vehicle 1 himself/herself, though the maximally attainable speed 9, see Fig. 2, during the parking manoeuvre 12 is reduced further and further in position-dependent manner in such a way that upon reaching the parking-space limits 19 the speed 10, 13 is equal to 0 km/h; see Fig. 2. During the traversing of the trajectory 3 the driver can thus remain constantly on the accelerator pedal of the motor vehicle 1 while the motor vehicle 1 automatically becomes slower and slower until it stops 15 on its own upon reaching the parking-space limit 19. The actuating of the pedals is, however, not separately interpreted, since the driver is, after all, still permitted to accelerate, see speed curve in Fig. 2, brake, see speed curve 13 in Fig. 2, and even stop, see reference symbol 14 in Fig. 2, independently.

Merely the maximally attainable driving speed 9 is adapted by the parking-assistance system.

Tests with drivers have shown, however, that dangerous situations may arise in the case of park-stop motor vehicles with automatic transmission. The cause is the fundamental behaviour of an automatic motor vehicle. As soon as the driver of an automatic motor vehicle releases the brake, in particular takes his/her foot off the brake pedal, the motor vehicle moves off on its own. In the case of a park-stop system in an automatic motor vehicle this behaviour is frequently interpreted as automatic' starting. In quite a few drivers this leads to the misjudgement that the parking manoeuvre is proceeding totally automatically and the driver is to take his/her feet off the pedals. This misjudgement is confirmed by the successfully running, automatically braked parking manoeuvre, which proceeds successfully without involvement of the driver. In consequence, the driver no longer reacts to the surroundings and relies too much on the motor vehicle. That is to say, the drivers no longer react, or no longer react in time, to collision warnings of the parking-assistance system which is likewise integrated within the motor vehicle.

One possibility to solve this problem and to guarantee a safe parking of a motor vehicle is constituted by sensorics that are 100 % reliable. That is to say, during the automatic parking of the motor vehicle, sensorics that are % reliable register the situation in the direction of travel and slow the vehicle down independently. However, for reasons of cost and effort this is frequently not practicable. And an automatic recognition and slowing-down that is merely, for example, 99 % successful is to be regarded as critical, since most of the time the driver will confirm that he/she can rely on the parking system, even though, given a high market penetration of the system, a situation will certainly arise in which the system fails.

Another possibility to solve this problem and to guarantee a safe parking of a motor vehicle requires that the driver constantly has to actuate the brake of the motor vehicle lightly so that the parking system recognises that the driver is able to slow down quickly and is aware of the danger. However, this solution is not accepted and/or understood by some drivers, since the actuating of the brake as a command for moving off contradicts the normal understanding of cause and effect in connection with the operation of a motor vehicle. Moreover, this concept is exclusively suitable for driving on flat surfaces. If the parking manoeuvre is to take place against a slope, the drive torque has to be increased, which does not occur without actuation of the accelerator pedal. That is to say, the driver would have to actuate the brake pedal and the accelerator pedal simultaneously.

A final suggested solution currently being discussed provides that the driver constantly has to actuate the accelerator pedal lightly in order to communicate to the parking system that he/she has control over the parking manoeuvre. In this case the position of the accelerator pedal corresponds to the driving speed envisaged. That is to say, if the driver releases the accelerator pedal, the motor vehicle immediately comes to a halt. This suggested solution is promising, since it attempts to correspond to the understanding of cause and effect -that is to say, an accelerator pedal is able to accelerate the motor vehicle.

However, the spontaneous retardation upon easing off the accelerator pedal slightly, without the accelerator pedal being actuated, is felt to be uncomfortable. Abrupt decelerations are the consequence. That is to say, the driver presses lightly on the accelerator, in order to nudge' the vehicle along as usual, and would then come off the accelerator pedal completely, which would result in an abrupt slowing-down of the motor vehicle.

It is therefore the object of the invention to guarantee during a parking manoeuvre, assisted by a parking system, in the case of a motor vehicle that the driver continues to retain responsibility concerning the motor vehicle and is able to react quickly to dangerous situations. In particular, the operating concept of the parking system that is being used is to correspond to the previous understanding of cause and effect in connection with the operation of a motor vehicle, and the parking of the motor vehicle on a slope is also to be possible without restriction.

In accordance with the invention this object is achieved by a process for automatic open-loop and/or closed-loop control of a motion of a motor vehicle having the features according to the independent Claim 1 and also by a parking system for a motor vehicle having the features according to Claim 8. Further features and details of the invention will become apparent from the dependent claims, from the description and the drawings. Features and details that are described in connection with the process also apply, of course, in connection with the parking system, and conversely, so that with respect to the disclosure relating to the individual aspects of the invention reference is always made reciprocally.

According to the first aspect of the invention, the object is achieved by a process for automatic open-loop and/or closed-loop control of a motion of a motor vehicle by a parking system in the course of a parking manoeuvre of the motor vehicle, the process being characterised by the following process steps: -a parking-space gauging system of the motor vehicle gauges a parking space, -a control unit of the motor vehicle calculates a trajectory on the basis of the measured data of the parking-space gauging system, -the parking manoeuvre for traversing the calculated trajectory is activated by actuation of the accelerator pedal, and by means of an open-loop and/or closed-loop control device the motor vehicle is moved in defined manner into the parking space during the actuation of the accelerator pedal, whereby the motor vehicle does not exceed a certain limiting speed, -as a result of the accelerator pedal being released, via the open-loop and/or closed-loop control device a defined reduction of the speed of the motor vehicle is effected until the motor vehicle comes to a standstill, the speed reduction of the motor vehicle being determined as a function of the current speed of the motor vehicle and as a function of the position of the motor vehicle along the trajectory.

A process of such a type for automatic open-loop and/or closed-loop control of a motion of a motor vehicle in the course of a parking manoeuvre of the motor vehicle makes it possible that during the parking manoeuvre assisted by a parking system the driver continues to retain responsibility concerning the motor vehicle and is able to react quickly to dangerous situations. In particular, the operation of the motor vehicle by the driver during the parking manoeuvre corresponds to the usual understanding of cause and effect in connection with the operation of the motor vehicle. A process of such a type for automatic open-loop and/or closed-loop control of a motion of a motor vehicle also enables the simple parking of the motor vehicle on a slope -that is to say, in the case of a gradient of the carriageway.

In a first step, an envisaged parking space is gauged by a parking-space gauging system of the motor vehicle. The parking-space gauging system of the motor vehicle exhibits suitable sensorics for this purpose. In particular, several transceiver units -that is to say, sensors -measure the spacing of the vehicle from possible obstacles.

The transceiver units are preferentially arranged in the bumpers of the motor vehicle. The transceiver units preferentially emit ultrasound or laser pulses or signals and receive the echo of the pulses or signals reflected on the corresponding obstacles.

In a second process step, a control unit of the motor vehicle calculates a trajectory on the basis of the measured data of the parking-space gauging system. In this step, the control unit, in particular a processor unit provided in the control unit, calculates from the time-difference between the emitted signals and the received signal the spacing of the motor vehicle from the at least one obstacle.

For the purpose of starting the actual parking manoeuvre -that is to say, of the motor vehicle to be moved -the driver actuates the accelerator pedal of the motor vehicle.

As is known, the driver has to actuate the accelerator pedal at least slightly in order to get the motor vehicle under way and to keep it going. By means of an open-loop and/or closed-loop control device of the motor vehicle, the motor vehicle is moved in defined manner into the envisaged parking space during the actuation of the accelerator pedal. In this connection the open-loop and/or closed-loop control device has been set in such a manner that the motor vehicle does not exceed a certain limiting speed. That is to say, during the parking manoeuvre the motor vehicle does not exceed a certain limiting speed. This limiting speed is capable of being set in or by the open-loop and/or closed-loop control device. By pressing on the accelerator pedal, the driver assists the parking manoeuvre and retains the feeling that he/she is actively controlling the parking manoeuvre.

As soon as the driver releases the accelerator pedal, via the open-loop and/or closed-loop control device a defined reduction of the speed of the motor vehicle is effected.

In this process the speed of the motor vehicle is reduced to 0 km/h -that is to say, until the motor vehicle is stationary. The speed reduction of the motor vehicle is determined by the open-loop and/or closed-loop control device as a function of the current speed of the motor vehicle and as a function of the position of the motor vehicle along the trajectory. If the driver takes his/her foot off the accelerator pedal, a controlled stopping manoeuvre -that is to say, a defined reducing of the speed of the vehicle -is effected until the vehicle comes to a standstill, whereby the driver experiences the stopping manoeuvre as coasting'. The stopping manoeuvre is determined and executed as a function of the parking condition' currently obtaining. That is to say, the vehicle does not slow down immediately but executes a situation-dependent stopping manoeuvre. Thus the speed of the motor vehicle is reduced more slowly when the motor vehicle is located at the start of the trajectory to be traversed than when the motor vehicle is located at the end of the trajectory. The open-loop and/or closed-loop control device only ensures that the motor vehicle does not exceed a certain limiting speed. The stopping manoeuvre is defined by the stopping distance -that is to say, the section of the trajectory yet to be traversed -and by the progression of the speed. The progression of the speed determines, in turn, the progression of the retardation and the jolt in the course of the reducing of the speed of the motor vehicle by the open-loop and/or closed-loop control device. If, for example, the driver takes his/her foot off the accelerator immediately after the start of the parking manoeuvre, the open-loop and/or closed-loop control device ensures that the motor vehicle still rolls a relatively long distance, for example 1.5 m, and in the process brakes the motor vehicle with a very slight jolt. But if the motor vehicle is already located, for example, half-inside the parking space, thus in a situation in which a pedestrian may have only little spacing from the parking motor vehicle when quickly passing through the parking space, the stopping manoeuvre is executed within a substantially shorter distance, for example 0.75 m.

As a result of the releasing of the accelerator pedal, the open-loop and/or closed-loop control device gives rise to a reduction of the speed of the vehicle, the reduction being made dependent on how quickly the motor vehicle is currently moving and on where the motor vehicle is located on the calculated trajectory. For this purpose, stopping characteristics are preferentially stored in the open-loop and/or closed-loop control device of the motor vehicle.

That is to say, the reduction of the speed of the motor vehicle is preferentially effected by means of stopping characteristics stored in the open-loop and/or closed-loop control device. By this means, the responsibility for the parking manoeuvre remains totally with the open-loop and/or closed-loop control device which is regarded as relevant to safety and which preferentially takes the form of a control unit.

In the process previously described for automatic open-loop and/or closed-loop control of a motion of a motor vehicle by a parking system in the course of a parking manoeuvre of the motor vehicle it is advantageous that the instruction for the driving of the motor vehicle is given, as usual, by the accelerator pedal. The attention of the driver is clearly drawn to the fact that he/she has to keep the motor vehicle in motion. Furthermore, comfort is preserved. The driver experiences no unnecessary abrupt decelerations if he/she takes his/her foot off the accelerator pedal. The process reduces the danger of running completely over an obstacle to approximately zero.

According to a preferred further development of the invention, in the case of the process there may be provision that the limiting speed that the motor vehicle does not exceed during the parking manoeuvre becomes continuously lower with the traversing of the trajectory.

That is to say, the parking system advantageously presets a limiting-speed curve for the parking manoeuvre along the calculated trajectory. Even in the case of a permanent complete forcing-through of the accelerator pedal, the motor vehicle does not exceed the preset limiting speed during the parking manoeuvre. The further the motor vehicle is already located within the envisaged parking space, the lower the preset limiting speed. By this means, the parking system guarantees that the motor vehicle is slowed down continuously during the traversing of the trajectory, even if the driver also undertakes nothing else by himself/herself -that is to say, for example, remains unchanged on the acceleration pedal. If the driver remains unchanged on the accelerator pedal after the starting manoeuvre, the motor vehicle drives into the parking space at the preset limiting speed, the speed of the motor vehicle being slowed down in a manner corresponding to the limiting speed, which is becoming lower, until the complete standstill of the motor vehicle occurs upon reaching the end of the trajectory, when reaching the desired parked position.

Below the limiting speed in the course of the process the driver can continue to exert influence on the motion of the motor vehicle by the actuation of the accelerator pedal.

Particularly preferred is a process wherein the reduction of the speed by the open-loop and/or closed-loop control device is effected as a function of the speed of releasing the accelerator pedal, the speed of the motor vehicle being reduced more intensely in the case of a rapid releasing of the accelerator pedal than in the case of a slow releasing of the accelerator pedal. That is to say, it is advantageous if the speed at which the driver releases the accelerator pedal has an influence on the stopping manoeuvre. The stopping distance of the motor vehicle can become longer, the more slowly the driver takes his/her foot off the accelerator pedal, or shorter, the more quickly the driver takes his/her foot off the accelerator pedal. By this means, the driver retains some influence on the parking manoeuvre. If, for example, the driver undertakes nothing -that is to say, remains unchanged on the accelerator pedal -the open-loop and/or closed-loop control device of the motor vehicle ensures that the motor vehicle comes to a standstill upon reaching the envisaged parked position. If the driver takes his/her foot off the accelerator pedal slowly during the parking manoeuvre, the open-loop and/or closed-loop control device of the motor vehicle ensures that the motor vehicle comes to a standstill slowly -that is to say, after traversing a still relatively long section, for example approximately the remainder of the trajectory to be traversed. On the other hand, if the driver takes his/her foot off the accelerator pedal quickly, the open-loop and/or closed-loop control device of the motor vehicle ensures that the motor vehicle comes to a standstill relatively quickly -that is to say, after traversing a relatively short section, for example half of the trajectory yet to be traversed.

Through the rapidity of the releasing of the accelerator pedal the driver can actively influence the stopping distance. By this means, the influence of reaction-time on the stopping distance is diminished. If the driver comes off the accelerator pedal quickly, the motor vehicle carries out a so-called emergency-stop manoeuvre.

According to another preferred further development of the invention, in the case of the invention there may be provision that upon detection of an object in the defined surroundings of the motor vehicle by sensorics of the parking-space gauging system the open-loop and/or closed-loop control device reduces the speed of the motor vehicle more intensely than if no object is detected. If, for example, an object, such as a person passing through, is registered in the vicinity of the rear of the motor vehicle by the sensors of the parking-space gauging system, the open-loop and/or closed-loop control device reduces the speed of the motor vehicle more intensely than normally provided for, so that the stopping distance of the motor vehicle is additionally shortened, for example by an additional 30 %, and as a result a perceptible braking jolt is generated. The intensity of the additional reduction of the speed of the motor vehicle may be variable. This can be stored in the open-loop and/or closed-loop control device in the form of special stopping characteristics. As soon as it is established that an object that was not yet present in the course of the gauging of the parking space is in a defined vicinity of the motor vehicle, the open-loop and/or closed-loop control device alters the reduction of the speed of the motor vehicle by selecting another special stopping characteristic in order to stop the vehicle -Alternatively or additionally, a process is advantageous wherein upon detection by a driver-viewing-angle recognition device that the driver of the motor vehicle is not looking in the direction of travel of the motor vehicle, the speed of the motor vehicle is reduced more intensely by the open-loop and/or closed-loop control device than when the driver is looking in the direction of travel of the motor vehicle. That is to say, if on the basis of the driver-viewing-angle recognition device it is detected that the driver is not looking in the direction of the rear of the vehicle when reversing, the open-loop and/or closed-loop control device reduces the speed of the motor vehicle more intensely than normally provided for, so that the stopping distance of the motor vehicle is additionally shortened, for example by an additional 30 %, and as a result a perceptible braking jolt is generated.

Here too, the intensity of the additional reduction of the speed of the motor vehicle may be variable. This can be stored in the open-loop and/or closed-loop control device in the form of special stopping characteristics. If, for example, it is detected that the driver is not looking in the direction of travel of the motor vehicle and that an object appears in the vicinity of the motor vehicle, for example within a radius of less than one metre, the open-loop and/or closed-loop control device can reduce the speed of the motor vehicle very distinctly, so that the stopping distance is drastically shortened by comparison with the stopping manoeuvre normally implemented. Thus the stopping distance can be reduced by 60 %, for example.

Furthermore, a process is preferred wherein the open-loop and/or closed-loop control device is an electronic stability-program control unit. For instance, a control unit that is already present in the motor vehicle and that is employed for the purpose of electronic stabilisation of the motor vehicle during the driving of the motor vehicle can also carry out the parking manoeuvre. By this means, costs can be saved.

By virtue of the process previously described, the parking state of the motor vehicle is, in particular, a combination of various quantities such as, for example, the position of the vehicle relative to the parking space, the instantaneous driving speed, vehicle-sensor signals of various sensors, such as distance values from the parking-assistance sensors, from one or more video sensors, from a rain sensor, from a driver-awake recognition, from a driver-viewing-angle recognition device, etc. The invention and its further developments, as well as the advantages thereof, will be elucidated in more detail in the following on the basis of drawings. Shown, in each instance schematically, are: Figure 1 a parking manoeuvre, known from the state of the art, of a motor vehicle into a parking space along a calculated trajectory, whereby a parking system of the motor vehicle undertakes the longitudinal guidance of the motor vehicle and stops the motor vehicle automatically upon reaching the parking-space limits, Figure 2 the speed and the limiting speed of the motor vehicle along the calculated trajectory according to Fig. 1, Figure 3 a motor vehicle with a braking system according to the invention, Figure 4 a parking manoeuvre of a motor vehicle into a parking space along a calculated trajectory, the motor vehicle being moved semi-automatically in accordance with the process according to the invention, Figure 5 the stopping distance still available and the intensity of the braking jolt in relation to the position of the motor vehicle along the calculated trajectory.

Elements with the same function and mode of action are provided in each of Figures 1 to 5 with the same reference symbols.

Fig. 1 shows a parking manoeuvre 12, known from the state of the art, of a motor vehicle 1 into a parking space along a calculated trajectory 3, whereby a parking system of the motor vehicle 1 undertakes the longitudinal guidance of the motor vehicle 1 and stops the motor vehicle 1 automatically upon reaching the parking-space limits 19, as described in the introduction to the description. In Fig. 2 the speed 10, 13 and the limiting speed 9 of the motor vehicle 1 along the calculated trajectory 3 -that is to say, over the stretch of the parking manoeuvre 12 -are represented.

In Fig. 3 a motor vehicle 1 with driven and steerable wheels 2 is represented, wherein the driven and steerable wheels 2 are positioned obliquely. Furthermore, the motor vehicle 1 exhibits a parking system, exhibiting a parking--space gauging system 4, a control unit 6 for calculating a trajectory 3 on the basis of ascertained data of the parking-space gauging system 4, an electric wheel drive 17, which enables a forward motion and reverse motion of the driven wheels 2, and also an electric steering drive 18 for setting the steering angle 13 of the driven wheels 2. The steering angle 1 of the driven wheels 2 of the motor vehicle 1 is the angle that the steerable wheels 2 take up relative to the longitudinal axis 27 of the motor vehicle in the case of a lock to the left or a lock to the right.

In a first step, an envisaged parking space is gauged by the parking-space gauging system 4 of the motor vehicle 1.

For this purpose the parking-space gauging system 4 of the motor vehicle 1 exhibits suitable sensorics 11, in particular several transceiver units which measure the spacing of the motor vehicle 1 from possible obstacles.

The transceiver units 11 are preferentially arranged in the bumpers of the motor vehicle 1. The transceiver units 11 preferentially emit ultrasound or laser pulses or signals and receive the echo of the pulses or signals reflected on the corresponding obstacles. In a second process step, a control unit 6 of the motor vehicle 1 calculates a trajectory 3 on the basis of the measured data of the parking-space gauging system 4. In this process the control unit 6, in particular a processor unit provided in the control unit 6, calculates from the time-difference between the emitted signals and the received signal the spacing of the motor vehicle 1 from the at least one obstacle, such as, for example, in Fig. 4 the parked motor vehicles 20, 21. Subsequently the control unit 6 sends control signals to the electric wheel drive 17 and to the electric steering drive 18 of the motor vehicle 1, as a result of which the motor vehicle 1 is caused to traverse the trajectory 3 automatically.

The motor vehicle 1 additionally exhibits a driver-viewing-angle recognition device 28 for ascertaining the viewing direction of the driver. Upon detection by the driver-viewing-angle recognition device 28 that the driver of the motor vehicle 1 is not looking in the direction of travel of the motor vehicle 1, the open-loop and/or closed-loop control device 7 reduces the speed of the motor vehicle 1 more intensely than when the driver is looking in the direction of travel of the motor vehicle 1. That is to say, if on the basis of the driver-viewing-angle recognition device 28 it is detected that the driver is not looking in the direction of the rear of the vehicle when reversing, the open-loop and/or closed-loop control device 7 reduces the speed of the motor vehicle 1 more intensely than normally provided for, so that the stopping distance of the motor vehicle 1 is additionally shortened, for example by an additional 30 %.

Fig. 4 shows a parking manoeuvre 12 of a motor vehicle 1 into a parking space along a calculated trajectory 3, the motor vehicle 1 being moved semi-automatically and in longitudinally guided manner in accordance with the process according to the invention. The driver of the motor vehicle 1 activates the parking manoeuvre 12 for the purpose of traversing the calculate trajectory 3 by actuation of the accelerator pedal of the motor vehicle 1.

In co-operation with the control unit 6, the open-loop and/or closed-loop control device 7 moves the motor vehicle 1 in defined manner into the parking space between the two parked motor vehicles 20, 21 during the actuation of the accelerator pedal by the driver. For this purpose the open-loop and/or closed-loop control device 7 traverses a certain stopping characteristic stored in the open-loop and/or closed-loop control device 7. In the course of traversing the trajectory 3 the motor vehicle 1 does not exceed a certain limiting speed 9. As a result of the accelerator pedal being released, via the open-loop and/or closed-loop control device 7 a defined reduction of the speed 10, 13 of the motor vehicle 1 is effected until the motor vehicle 1 comes to a standstill, the speed reduction of the motor vehicle 1 being determined as a function of the current speed 10, 13 of the motor vehicle 1 and as a function of the position 5, 8 of the motor vehicle 1 along the trajectory 3.

The motor vehicle 1, which is preferentially equipped with a park-stop function, begins, for example, to park in reverse into the parking space bounded by the two parked vehicles 20, 21 on the trajectory 3. At position 5 on the trajectory 3 the driver takes his/her foot off the accelerator pedal, whereupon the motor vehicle 1 coasts gently' -that is to say, with a slight braking jolt 22 -and after the end of the stopping distance wi comes to a standstill 24. Subsequently the driver accelerates the motor vehicle 1 again. When the motor vehicle 1 has entered the parking space, at position 8 along the trajectory 3 the driver again takes his/her foot off the accelerator pedal, whereupon the motor vehicle 1 comes to a standstill 25 within the shortened stopping distance w2, which is shorter than the stopping distance wi, and with a perceptible bigger braking jolt 23.

Represented in Fig. 5 is an example of a possible running-condition-dependent parking behaviour, saved in the control unit 6 as a stopping characteristic. The continuous curve 26 represents the stopping distance as a function of the position -that is to say, the distance travelled -on the parking trajectory 3. At the start of the parking manoeuvre 12 a relatively long stopping distance wi is possible; at the end of the parking manoeuvre 12 the possible stopping distance w2 is shorter. The dashed curve 16 represents the intensity of the braking jolt that the motor vehicle 1 executes in controlled manner. At the beginning, only a slight braking jolt 22 is triggered, as a result of which a so-called gentle' stopping of the motor vehicle 1 is made possible. Towards the end of the parking manoeuvre 12 a big braking jolt 23 is set which is clearly perceptible for the driver.

The process enables the implementation of a transversely guided and partly longitudinally guided parking manoeuvre in the case of a motor vehicle 1. The instruction for driving is given by the driver, as usual, by means of the accelerator pedal of the motor vehicle 1. The attention of the driver is clearly drawn to the fact that he/she has to keep the motor vehicle 1 in motion. Comfort is preserved -that is to say, the driver experiences no unnecessary abrupt decelerations if he/she takes his/her foot off the accelerator pedal. The danger of running completely over an obstacle is reduced by the process.