DE10225894A1 - Motor vehicle parking assistance method in which a vehicle has an onboard parking assistance system with a sensor that transmits a signal that is reflected back, with vehicle separation determined from the time between signals - Google Patents

Abstract

The method for determining a distance (a) between two objects, especially motor vehicles (34, 36), in the same plane using a system (10, 12) that moves past them in an essentially parallel direction. According to the method the system has a sensor (100) that transmits signals (S1, S2) at a time interval to each other. The signal is reflected back from objects within a flat or solid angle (30) of the sensor. From the sensor relative positions (PS), when the two signals are reflected back, the object separation is determined.

Description

technical area

The invention relates to a method to determine a distance between two essentially in objects located on a plane by an essentially parallel to the objects passing system.

It is generally known to do so on motor vehicles to arrange the distance warning, which can be arranged, for example, by means of a Ultrasonic measurement, acoustic warning signals when the distance a predeterminable minimum value for a front or rear vehicle below. Such facilities can be used as parking aids become.

From the DE 196 16 447 A1 a method for determining the length of a parking space between a front and a rear parked vehicle is known. Here, during a slow drive past at least the rear parked vehicle using at least one transmitting and receiving device for signal beams by evaluating backscatter signals, the position of the moving vehicle in the direction of travel relative to the front end of the rear parked vehicle and starting from this position the distance of the front parked vehicle is determined by the moving vehicle and from this the distance of the two parked motor vehicles to one another is determined.

From the DE 297 18 862 U1 An arrangement for facilitating the parking of motor vehicles is known, in which a length of a parking space is determined by means of a displacement sensor, which is arranged on a vehicle moving past the parking space.

A disadvantage of the known solutions is that for the Measurement of the parking space only one sent at a first time and at a second Indication signal received at the time is available. Thereby exists a source of error so that the determined length of the parking space with Inaccuracies.

From the DE 41 37 068 A1 an integrated optical multiple distance sensor is known, in which a distance measurement is carried out according to the triangulation principle for the position detection of objects in a surface or solid angle range.

It is an object of the present invention Method of the generic type specify the distance between two in a simple manner objects can be determined quickly and precisely by a moving system.

This task is accomplished through a process solved with the features characterized in claim 1.

The inventive method with the claim Features mentioned 1 offers the advantage that the distance between two essentially in one plane objects by one system moving essentially parallel to the objects can be determined with high accuracy. By that of the system is spaced in time in the direction of movement by means of a sensor at least a first and a second sensor signal is sent and in an area or solid angle range of the first and second sensors Object reflected and received again at a time will and the associated relative positions of the sensor to each other can be determined and the distance is determined from this, is advantageously possible, despite the moving system the distance of the objects with high accuracy determine.

In a preferred embodiment of the Invention is the sensor part of a multi-sensor Parkpilot systems with integrated parking space measurement system (PLV).

The sensor is used both as a parking pilot sensor also as a sensor for parking space measurement used. The distance of the objects, especially stationary parked motor vehicles, preferably provides a parking space for a motor vehicle represents.

Determining the distance between the Motor vehicles are preferably constant at a predetermined level Angle to a longitudinal axis of the moving system aligned sensor realized.

In a further preferred embodiment The invention uses sensor signals from the sensor in a surface or Solid angle range formed and at corresponding angles right and left in the direction of travel, preferably in the front area of the motor vehicle, to a longitudinal axis of the system. Dependent on of whether the objects to the left or right of the motor vehicle, the left or right Sensor activated.

Further the relative positions the sensor signals of the sensor when the first object is detected in a first time interval and in a second time interval and relative positions of the sensor signals of the sensor when detected of the second item in a further first time interval and alternatively in a further second time interval by a Travel signal transmitter, a combination of travel signal transmitter and steering angle transmitter, using a satellite-based Positioning system (GPS) or taking into account a measured System speed in the first and second time intervals determined or calculated.

In a further preferred embodiment The invention uses at least two spaced apart Positions of the first object and at least two relative to each other spaced positions of the second object using a triangulation method certainly. From the, at least two positions of the first and second Item is created a position for each item.

It also becomes relative to each other spaced positions of the first and second objects in turn alternatively by means of the way signal transmitter, a combination of way signal transmitter and steering angle encoder or by means of a satellite-based positioning system (GPS) determines the distance between the objects.

The distance (parking space) of the relatively spaced positions of the first and second Subject is also alternative to those described above Methods by consideration a measured speed of the system between the first and second time intervals are calculated.

It is particularly beneficial that the exact determination of the length the parking space by determining the positions of the objects with only one sensor the basis of the triangulation measurements and thus a statement is derived with which it is possible it is to be determined whether the own motor vehicle fits into the existing parking space.

The at least two sensor signals each Sensor with subsequent This advantageously determines the position of the objects possible, because the antenna characteristics of a wide lobe with a narrow one This changed the antenna becomes that the antenna by adding multiple positions virtually is enlarged, resulting in better resolution is achieved. This type of evaluation of the signals - also as called synthetic aperture - is implemented, which is advantageous the triangulation of objects performed with only one sensor becomes.

The triangulation enables that from several known sensor positions the position of the objects in space can be better reconstructed.

Furthermore, in a preferred embodiment the invention provides that the inventive method in the determination the length a parking space between a front and a rear parked vehicle during the Passing a vehicle is used.

As a result, a parking space measurement with high accuracy possible, so that a driver information is immediately available to the passing vehicle, whether the length of the measured parking space is sufficient for parking.

It is also more preferred Embodiment of the invention provided that the distance determined between the objects (parked motor vehicles) automatically with a predefinable value for one Minimum distance (minimum length a parking space) is comparable and the result of the comparison is displayed. The display can preferably be visual and / or acoustic. It is preferred here if the display only takes place when the Distance of objects (parked motor vehicles) is larger than the predeterminable minimum distance. It is further preferred here if upon detection of an over the predeterminable minimum distance between the objects (parked motor vehicles) automatically a parking pilot initiates a parking process of the parking space passing vehicle. This will make one as possible fast and safe parking of the vehicle possible, so that a hindrance to further flowing traffic to a minimum limited remains.

Further preferred configurations the invention result from the remaining, mentioned in the subclaims Features.

The invention is hereinafter described in embodiments based on the associated Drawings closer explained. Show it:

1 a schematic plan view of a motor vehicle;

2 another schematic plan view of the motor vehicle;

3 schematically a measuring process for determining a distance and

4 a block diagram with the sequence of the method for determining the distance.

Best way to run the invention

1 shows a schematic plan view of a motor vehicle designated overall by 10. The car 10 includes a parking aid system 12 (Park Pilot). The parking aid system 12 includes a control unit 14 that about connections 16 with external sensors 100 , middle sensors 100 ' and central sensors 10 '' connected is. According to the embodiment shown, are in a front area 20 of the motor vehicle 10 a total of six sensors, two external sensors 100 , two middle sensors 100 ' and two central sensors 100 '' and in a rear area 22 of the motor vehicle a total of four sensors, two middle sensors 100 ' and two central sensors 100 '' arranged. Relative to a longitudinal axis 24 of the motor vehicle 10 are in the front area 20 three sensors each to the right and left of the longitudinal axis 24 and in the rear area 22 two sensors each to the right and left of the longitudinal axis 24 arranged. The sensors 100 . 100 ' and 100 '' each have a broadcast and Receiving device for signal beams. The outside sensors 100 , the middle 100 'and central sensors 100 '' each have a main direction of action (main beam direction).

The control unit 14 is also with a position sensor 26 and / or a steering angle sensor 28 and / or a global positioning system (GPS system).

The outside sensors 100 , the middle 100 'and central sensors 100 '' can be, for example, ultrasonic sensors, radar sensors, video sensors or the like.

The general structure and mode of operation of the parking aid system 12 are known, so that they will not be discussed in more detail in the context of the present description.

Based on 2 is in a further top view of the motor vehicle 10 the main direction of action of the respective outer sensors 100 , the middle 100 'and central sensors 100 '' of the parking pilot in the front area 20 and in the rear area 22 shown. In addition to the main direction of action, the sensors each form an outer, middle and central area or solid angle range 30 . 30 ' and 30 '' to both sides of the motor vehicle.

The main direction of action of the central sensors 100 '' in the front area 20 runs essentially parallel to the longitudinal axis 24 and forms the solid angle range 30 '' out.

The main direction of action of the middle sensors 100 ' or external sensors 100 runs at a corresponding angle β or α to the longitudinal axis 24 , According to the beam direction of the middle sensors 100 ' and external sensors 100 in the front area 20 do the corresponding angles ß open? in an imaginary direction of travel 32 of the motor vehicle 10 and form the middle and outer solid angle ranges 30 ' and 30 out.

Contrary to the intended direction of travel 32 in the rear area 22 there are two sensors each, middle sensors 100 ' and central sensors 100 '' range with the respective central and central solid angle 30 ' and also under the corresponding angle ß and 30 '' essentially parallel to the longitudinal axis 24 ,

The angles α and β are variable and can be in the front area 20 or in the rear area 22 be chosen different sizes.

The sensors 100 are used to implement the method according to the invention only in the front area 20 needed and arranged.

Based on 3 becomes the mode of operation of the parking aid system 12 to determine the length of a parking space. Same parts as in 1 are provided with the same reference numerals and are not explained again. In addition, only the mode of operation is based on one in the direction of travel 32 right in the front area 20 arranged outer sensor 100 explained.

How the parking aid system works 12 to determine the length of a left of the imaginary direction of travel 32 parking space is carried out analogously.

In 3 is shown that the motor vehicle 10 itself in the direction of the arrow shown 32 on schematically indicated parked motor vehicles 34 or 36 moved past.

Will the parking assistance system 12 is switched into a parking space measurement mode, for example by a vehicle driver, by means of the parking assistance system 12 a distance a between the motor vehicles 34 and 36 certainly.

That slowly from behind on the rear parked vehicle 34 passing vehicle 10 with the integrated parking aid system 12 is with the transmitting and receiving device, the outer sensor 100 equipped in the direction of travel 32 right outer area or solid angle range 30 radiates with a side and a front boundary.

The front limit results from a falling intensity of the sensor beam with increasing distance from the vehicle 10 and an evaluation module 40 in the control unit 14 of the vehicle 10 which only evaluates sensor signals above a certain intensity threshold.

In 3 is the vehicle 10 with a length I in four by the movement of the motor vehicle 10 progressive positions together with the associated four outer surface or solid angle areas 30 shown.

With the parking space measurement mode (PLV) of the parking aid system switched on 12 is from the outer sensor 100 a sensor signal S1 is sent at a specific position Ps1 at time t1 at the known predetermined angle α. The sensor signal S1 is from the vehicle 34 reflected and from the sensor 100 at the position Ps1 'of the passing vehicle 10 received again at time t1 '.

At time t2 the sensor 100 a second sensor signal S2 emitted at the same known angle α and in turn from the vehicle 34 reflected with a certain intensity and from the sensor 100 at time t2 'at position Ps1' of the motor vehicle 10 received again.

The relative positions Ps1, Ps1 ', Ps1 and Ps1' of the transmitted and received sensor signals S1 and S2 of the sensor 100 are through the parking assistance system 12 which the control unit 14 includes, determined in different ways.

First, the relative positions Ps1, Ps1 ', Ps2 and Ps2' of the motor vehicle 34 by the way signal transmitter 26 certainly.

Secondly, the relative positions Ps1, Ps1 ', Ps2 and Ps2' are due to the combination of position signaling devices 26 and the steering angle sensor 28 certainly.

Alternatively, the third party to determine the relative position Ps1, Ps1 ', Ps2 and Ps2 'a global positioning System (GPS system) used.

Taking into account a measured speed v of the motor vehicle 10 As an alternative to the fourth, the determination between the times t1, t1 'and t2, t2', the relative position Ps1, Ps1 ', Ps2 and Ps2' of the sensor signals S1 and S2 is possible.

The sensor signals S1 and S2 reach during the measuring process of the motor vehicle 34 the vehicle 36 not yet, so that it is influenced by reflective signals from the vehicle 36 , is excluded.

The at least two first and second sensor signals S1 and S2, which are spaced in short succession, enable the motor vehicle to be detected precisely 34 possible. With decreasing intensity, the signals Ps1 'and Ps2' become as long as the motor vehicle 34 to receive characteristic sensor signals until the evaluation stage of the control device reports that the intensity falls below a certain threshold, which means that the front end of the motor vehicle 34 is detected.

An exact position of the motor vehicle 34 is in turn calculated by the triangulation method known per se, from which a position Pg1 'and a Pg2' result.

The positions Pg1 'and Pg2' of the motor vehicle are then used to simplify the method 34 a position signal Pg 'is formed.

The control of the sensor 100 or the evaluation of the from the motor vehicle 34 reflective sensor signals S1 and S2 by the sensor 100 takes place by means of the control unit 14 ( 1 ).

After the motor vehicle 10 has passed the parking space with the distance a takes place after the detection of the second motor vehicle 36 an analogous process of the inventive method.

The passing vehicle 10 with the parking aid system 12 moves slowly at speed v on the motor vehicle 36 past. At time t1, a first sensor signal S1 is sent out at a position Ps1 at the predetermined same angle α and at time t1 ″ at position Ps1 ″ from the sensor 100 received again. A second sensor signal S2 at time t2 at position Ps2 is spaced in time at the same angle? sent and received again at time t2 '' at position Ps2 ''. The positions Ps1, Ps1 '', Ps2 and Ps2 '' are in turn those with the control unit 14 of the park pilot 12 connected systems, the path signal transmitter 26 , a combination of a signaling device 26 and steering angle sender 28 , the GPS system (Global Positioning System) or taking into account the measured speed v of the motor vehicle 10 determined between times t1, t1 "and t2, t2".

Then the known Triangulation method a position Pg1 '' and a position Pg2 ″ determined and preferably a position Pg '' is formed therefrom.

The method according to the invention thus provides precise position data of the stationary, parked motor vehicles 34 and 36 in the form of the positions Pg 'and Pg''.

As the geometry of the positions Pg ', Pg''and all the necessary information about the motor vehicle 10 the distance a is calculated.

The distance a between the positions Pg 'and Pg'', which is the parking space between the motor vehicle 34 and the motor vehicle 36 is now taking into account the measured speed of the vehicle 10 determined between the time intervals t1, t2 'and t1, t2''.

The distance traveled - distance a - between the time intervals t1, t2 'and t1, t2''is alternatively by the distance signal generator 26 , through the combination of a signaling device 26 and the steering angle sensor 28 or determined by the Global Positioning System (GPS system).

Because the control unit 14 furthermore information about the total length I of the motor vehicle 10 has, it can be determined by a simple comparison of the distance a with the length I whether the parking space between the motor vehicles 34 and 36 for parking the motor vehicle 10 is sufficiently large. Here, the control unit 14 a threshold value S is stored, the value of which is greater than a value corresponding to the length I. This threshold value S defines a minimum distance a _{min of} the motor vehicles 34 and 36 to park the motor vehicle 10 necessary is. Will now be through the parking assistance system 12 If a> a _{min is} determined, the parking process can be started either by the driver or automatically by the parking pilot.

From the explanations, it is clear that the parking space measurement mode can easily be incorporated into an existing control unit 14 a parking aid system 12 can be integrated.

The outside sensors 100 , middle sensors 100 ' and central sensors 100 '' are preferably structurally identical, so that the outlay on equipment for a motor vehicle 10 limit. Should be a motor vehicle 10 can only be operated in a parking space measurement mode on the middle sensors 100 ' and central sensors 100 '' in the front and rear area 20 . 22 to be dispensed with.

3 illustrates in a block diagram the sequence of the method for determining the distance a.

The elements shown are in the control unit 14 accommodated.

From the sensor 100 position signals Ps1, Ps1 ', Ps2 and Ps2' of the first motor vehicle 34 as well as position signals Ps1, Ps1 '', Ps2 and Ps2 '' of the second motor vehicle 36 a position module 38 transmitted.

The position module 38 holds in parallel the first time interval t1 / t1 'and the second time interval t2 / t2' of the first motor vehicle 34 and the first time interval t1 / t1 "and the second time interval t2 / t2" of the second motor vehicle 36 firmly.

The building block 38 alternatively, the signals of the way signal transmitter 26, a combination of way signal generator 26 and the steering angle sender 28 , the Global Positioning System (GPS system), the surface or solid angle α, the length I of the motor vehicle 10 and the speed v is transmitted between t1, t1 ', t2, t2' and t1, t1 '', t2, t2 '' and between t1 ', t2' and t1, t2 ''.

About the known relative positions Ps (Ps1, Ps1 'and Ps2, Ps2' and Ps1, Ps1 '' and Ps2, Ps2 '' of the external sensor 100 on the motor vehicle 10 and the known angle? positions Pg1 'and Pg2' of the motor vehicle are determined by means of the triangulation method 34 and Pg1 "and Pg2" of the motor vehicle 36 determined.

The positions Pg 'and Pg''which are preferably determined therefrom are, in turn, alternatively with the aid of the path signal transmitter 26 , a combination of a signaling device 26 and the steering angle sensor 28 , the global positioning system (GPS system) or taking into account the measured speed v of the system between times t1 / t2 'and t1 / t2''the distance a between the motor vehicles 34 and 36 determined.

Signal a becomes the evaluation module 40 supplied, which receives the signal a _min , the minimum necessary distance a _min for parking the motor vehicle 10 Are defined. This depends on the length I of the motor vehicle 10 and the maneuverability of the motor vehicle 10 , If the signal a is greater than the signal a _min , the evaluation module delivers 40 a parking signal x. The parking signal x can either be fed optically and / or acoustically to a vehicle driver or it serves as a control signal for an automatic parking means of a parking pilot.

Claims (18)

Method for determining a distance (a) between two first and second objects located essentially in one plane ( 34 . 36 ), in particular motor vehicles, by means of a system that moves past the objects essentially in parallel ( 10 ), characterized in that by the system ( 10 ) using a sensor ( 100 ) in the direction of movement ( 32 ) at least a first and a second sensor signal (S ₁ , S ₂ ) are sent at intervals and in a surface or solid angle range ( 30 ) of the sensor ( 100 ) the first and second object ( 34 . 36 ) is reflected and received at a time interval and the associated relative positions (Ps) of the sensor ( 100 ) are determined to each other and the distance (a) is determined from them. Method according to Claim 1, characterized in that the sensor signals (S1, S2) of the sensor ( 100 ) forming area or solid angle range ( 30 ) at a corresponding angle (α) to a longitudinal axis ( 24 ) of the system ( 10 ) is sent out. A method according to claim 1, characterized in that relative positions (Ps1, Ps1 ') and (Ps2, Ps2') of the sensor signals (S1, S2) of the sensor ( 100 ) when capturing the first item ( 34 ) in a first time interval (t1, t1 ') and in a second time interval (t2, t2') and relative positions (Ps1, Ps1 '') and (Ps2, Ps2 '') of the sensor signals (S1, S2) of the sensor ( 100 ) when capturing the second item ( 36 ) in the first time interval (t1, t1 '') and in the second time interval (t2, t2 '') by a displacement signal generator ( 26 ) can be determined. A method according to claim 1, characterized in that the relative positions (Ps1, P1 ') and (Ps2, Ps2') of the sensor signals (S1, S2) of the sensor ( 100 ) when capturing the first item ( 34 ) in the first time interval (t1, t1 ') and in the second time interval (t2, t2') and the relative positions (Ps1, Ps1 '') and (Ps2, Ps2 '') of the sensor signals (S1, S2) of the sensor ( 100 ) when capturing the second item ( 36 ) in the first time interval (t1, t1 '') and in the second time interval (t2, t2 '') by a combination of displacement signal transmitter ( 26 ) and a steering angle sensor ( 28 ) can be determined. A method according to claim 1, characterized in that the relative positions (Ps1, Ps1 ') and (Ps2, Ps2') of the sensor signals (S1, S2) of the sensor ( 100 ) when capturing the first item ( 34 ) in the first time interval (t1, t1 ') and in the second time interval (t2, t2') and the relative positions (Ps1, Ps1 '') and (Ps2, Ps2 '') of the sensor signals (S1, S2) of the sensor ( 100 ) when capturing the second item ( 36 ) in the first time interval (t1, t1 '') and in the second time interval (t2, t2 '') by a satellite-based positioning system (GPS). A method according to claim 1, characterized in that the relative positions (Ps1, Ps1 ') and (Ps2, Ps2') of the sensor signals (S1, S2) of the sensor ( 100 ) when capturing the first item ( 34 ) in the first time interval (t1, t1 ') and in the second time interval (t2, t2') and the relative positions (Ps1, Ps1 '') and (Ps2, Ps2 '') of the sensor signals (S1, S2) of the sensor ( 100 ) when capturing the second item ( 36 ) in the first time interval (t1, t1 '') and in the second time interval (t2, t2 '') taking into account a measured speed (v) the system ( 10 ) in the time intervals (t1, t1 ') (t2, t2') (t1, t1 '') (t2, t2 ''). A method according to claim 1, characterized in that positions (Pg1 'and Pg2') of the first object ( 34 ) and positions (Pg1 '' and Pg2 '') of the second object ( 36 ) can be determined using the triangulation method. Method according to one of the preceding claims, characterized characterized in that a position signal Pg 'from the position signals (Pg1' and Pg2 ') and from the position signals (Pg1 '' and Pg2 '') a position signal Pg '' is formed. Method according to one of the preceding claims, characterized in that the distance (a) (parking space) between the first, front object ( 34 ) and the second, rear object ( 36 ) is determined from the positions Pg 'and Pg''. Method according to one of the preceding claims, characterized in that the distance (a), the relative positions Pg 'and Pg''from each other, by the path signal transmitter ( 26 ) is determined. Method according to one of the preceding claims, characterized in that the distance (a), the relative positions Pg 'and Pg''from one another, by the combination of displacement signal transmitter ( 26 ) and a steering angle sensor ( 28 ) is determined. Method according to one of the preceding claims, characterized characterized in that the distance (a), the relative positions (Pg ') and (Pg' ') to each other, by the satellite-based positioning system (GPS) is determined. Method according to one of the preceding claims, characterized in that the distance (a), the relative positions (Pg ') and (Pg'') to one another, taking into account the measured speed (v) of the system ( 10 ) between the times (t1, t2 ') and (t1, t2'') is calculated. Method according to one of the preceding claims, characterized in that the distance (a) (parking space) is compared with a predeterminable value for a minimum distance (a _min ) and the result of the comparison is displayed. Method according to one of the preceding claims, characterized in that depending on a result of the comparison, in particular if a> a _min , a parking process of a motor vehicle ( 10 ) is triggered. Method according to one of the preceding claims, characterized in that the minimum distance (a _min ) as a function of a length (I) of the motor vehicle ( 10 ) and maneuverability of the motor vehicle ( 10 ) is specified as a threshold (S). Method according to one of the preceding claims, characterized characterized that the parking process by a parking pilot triggered becomes. Method according to one of claims 1 to 16, characterized in that that the parking process is triggered by a driver.