DE102005061718A1 - Recognizing parking spaces involves transmitting signals laterally from vehicle as it is driven along, receiving reflected signals, deriving information about length, lateral extent of space from signal transition time and motion of vehicle - Google Patents

Abstract

The method involves at least one transmitter and receiver device mounted on the vehicle transmitting signals laterally from the vehicle as it is driven along, receiving the reflected signals and deriving information about the length and lateral extent of the parking space from the signal transition time and the motion of the vehicle.

Description

The The invention relates to a method for detecting a parking space for a Vehicle.

such Procedures are used in vehicle technology for parking in a parking space or to facilitate a parking space.

Known Support parking assistance parking by means of distance sensors arranged at the rear of the vehicle, wherein issued when falling below a minimum distance a warning signal becomes.

Unfortunately, are in known parking aids the ease of use and exploitation of a potential parking place not optimal.

Of the The present invention is therefore based on the object method to detect a parking lot, which is the recognition and the exploitation of a potential parking lot with improved Comfort optimized.

These The object is achieved by a Method solved with the features of claim 1.

To The invention will be laterally of the vehicle in the direction of a potential Parking lot or a potential parking space by means of at least one on or in a vehicle arranged transmitting and receiving device while of driving sent sensor signals. The reflected on an object Signals are received again and together in terms of runtime evaluated with the vehicle movement, so that thereby information about length and gain lateral extent of the parking lot.

One Such so-called scanning or scanning of the parking lot can in this case cyclically, for example, with a predetermined duration in a range of 20 to 100 ms, preferably in the range of 30 up to 80 ms, which is for the slow driving in the parking search, for example, under 30 km / h is sufficient to the potential parking in sufficient quality or resolution to scan. Of course but it is also conceivable, the cycle time as a function of vehicle speed adapt.

In preferred embodiment of the invention are used as sensor signals Transmitted and received ultrasonic signals. This diminishes due the low range, for example, a maximum of 5 m, the susceptibility to interference scanning.

In Further embodiment of the invention are received signals only above a predetermined signal strength threshold evaluated the signal propagation time. This can advantageously disturbances, such as reflections of lesser (receive) signal strength be avoided by bumps, bumps, etc. moreover can further threshold values are used as test parameters to avoid false identifications. For example, it is conceivable to recognize a parking space only as such or the determination to accept in the evaluation, if a front and rear Limit, ie length of the parking lot was detected and preferably this length below a predetermined threshold (for example, less than 15 m). Here you can the thresholds in dependence stand to the vehicle speed, so that error results through different signal strengths due reduced or different vehicle speeds can even be avoided.

In Further embodiment of the invention, the method for parking space detection automatically when falling below a predetermined vehicle speed, For example, started under half of 30 km / h, so that advantageously the comfort further increased becomes. Of course However, it is also conceivable, the procedure by an active intervention (actuation of a Switch or buttons, push of a button, etc.) of the operator, for example Driver, to start.

In preferred embodiment of the invention, the parking of the Vehicle in the determined parking space by means of a dependent of the determined parking space calculated Einparkbahnkurve. The parking process can then proceed through appropriate instructions to the driver. In this case, it is advantageously possible that at least the steering movements of the vehicle by means of a corresponding control device automatically or automatically be made.

In Another embodiment of the invention can for calculating the Einparkbahnkurve including at least one forward and at least one backward movement, to make the most of the parking space or to allow parking in very small parking lots.

at The determination of the parking curve can be geometric or trigonometric Correction methods are applied to measuring errors, in particular due to the vehicle speed increasing occurring runtime errors, to avoid.

Of course it is It is conceivable for a driver at any time, both in the determination of the trajectory, as well as the steering movements, a To allow intervention.

In preferred embodiment of the invention, the entire signal processing takes place in the invention preferably in real time, i. within a cycle a signal is sent, received and evaluated, so that the Result immediately available stands. The determination or recognition of the parking lot and the Einparkbahnkurve takes place here automatically, without the driver intervene to optimize or correct the result.

Further advantageous embodiments of the invention will become apparent from the Dependent claims.

The Invention will follow with reference to a shown in the drawing Embodiment explained in more detail.

In show the drawing:

1 a schematic representation of the different vehicle positions in a recognition of a parking lot according to the invention and

2 a schematic representation of a time course of the signal path in the vehicle positions after 1 ,

In 1 are the different vehicle positions 1a to 1f a vehicle, in particular a car, while driving past F in a parking lot 10 or a parking space. If the vehicle moves below a predetermined threshold speed of, for example, 30 km / h, the inventive method for detecting a parking space is started automatically. Alternatively, the method may be started at the instigation of the driver or passenger, for example, by pressing a button, to make a parking space if necessary 10 to seek and to recognize.

If the method has been started (automatically or on reason), the distance is closed by means of one or more ultrasonic sensors arranged laterally on or in the vehicle (transmitter and receiver, for example in the door, turn signal, on or in the front or rear bumper, etc.) a seitli chen obstacle detected. Here, the in 1 schematically illustrated line 5 one or more consecutively parked vehicles or other objects forming a lateral boundary, so that the distance to these vehicles or objects detected by the ultrasonic sensor and monitored by means of a control and evaluation. Of course, the method according to the invention is not limited to timely search and recognition of parking spaces, as seen in the direction of travel 1 shown, but may also be left-hand side, for example in the case of a one-way street, left-hand traffic, etc. applied.

While driving past a parking lot 10 , as in 1 shown here are the differently detected distances 3a to 3f to an obstacle or to an object 11 detected. These distances 3a to 3f are preferably measured cyclically, for example within a cycle of preferably 30 ms duration, in real time, recorded and evaluated. For this purpose, the distances can be entered, for example, in an X / Y diagram or transformed into a 2D coordinate system, wherein the X-axis stands for the lateral distance and the Y-axis (time axis) for the different times of the measurements or directly for the Length of potential parking space or parking lot 10 (which can be determined on the basis of the known vehicle speed) stands.

This will, as in 1 can be seen by means of the laterally and substantially perpendicular to the direction schematically indicated by dashed lines measurements of the distances 3a to 3f a parking lot 10 detected both in its length, as well as in its width or depth.

The evaluation can in this case, for example, a first increase in distance of a successive distance measurement, as at the vertex 5a in 1 shown. Such a corner is formed for example by the front edge of a parked vehicle, in front of which - at least not in the immediate vicinity - no other vehicle parked. As a result, in position 1a the vehicle a greater distance 3a measured as before compared to the parked vehicles according to line 5 ,

The following is in the positions 1b to 1d the depth or width of the parking lot 10 detected and evaluated to see whether this depth is greater than the vehicle width and thus sufficient as a parking lot. Are the ultrasonic signals used to determine the distances 3a to 3d not from an object 11 reflects or lies an object 11 outside the range of the ultrasonic sensor, for example, 5 meters, so in the X / Y diagram as (depth) limit at least the vehicle width can be used, so that thereby in the detection of the parking lot 10 in this case, instead of a real boundary in depth, a virtual border 7 can be set.

Once a sufficient number of consecutive measurements of a parking lot depth 10 of at least the vehicle width or the vehicle length with additional necessary maneuvering space of, for example, 0.5 meters to 1 meter corresponds, it could be at the detected potential parking 10 to trade a real parking lot.

For further security, a query may be included in the recognition whether the recognized parking lot 10 in length is below a predetermined threshold of, for example, 15 meters or less, so that not unnecessarily error results, such as the end of a park row in front of an intersection and thus the intersection itself be recognized as a possible parking space. Such a limitation is in 1 when passing the vehicle at the potential parking lot 10 through the corner 9a represented, which stands, for example, for the rear end or rear of a parked vehicle after a parking space. At the transition from position 1d to 1e is therefore from the ultrasonic sensor from the corner 9a a reduction of the lateral distance 3b to 3c to 3d measured so that the vertex 5a as the front and the corner 9a as the rear end of the elongated extension of the parking lot 10 be detected and recognized.

If the measurement is cyclical, both the parking space length and the parking space depth are discreetly detected at the predetermined intervals of the cycle duration, so that resulting tolerances of course in the evaluation of the parking lot 10 must be taken into account.

The evaluation or evaluation of the sensor signals with respect to an edge contour of a parking space 10 In this case, for example, by means of a plurality of, preferably parallel, state machines, for example, six state machines for the positions 1a to 1f , respectively. In this case, the sensor signals detectable in the different positions can each be matched with the data (for example stored in the memory) of a required predetermined parking space or its dimensions.

To the quality in terms of detection, whether the parking lot 10 was scanned at sufficiently high density, further increase, a spatial model of the sensitivity of the sensors can be included in the evaluation. Here, the parameterized 3D distributions are projected onto a flat 2D grid and superimposed for successive ultrasound pulses or several sensors. Using a probabilistic approach, it is then possible to derive a measure of the coverage of the parking area or of the parking space, which at the same time quantifies the reliability of the recognition.

If the recognition process concludes in the evaluation that it is a sufficiently large and suitable parking space, the driver is issued, for example, with an audible or visual alarm or message, so that the latter is in a possibly likewise predetermined position, for example 1e , stops to allow an optimal starting position for parking.

The Parking itself can preferably by means of automatically performed steering movements be made by means of a corresponding control device, wherein the driver by the inventive method or system in terms the forward and backward movements as well as accelerating, braking and stopping appropriate instructions from System receives.

Of course, it is conceivable that not only an optimal Einparkbahnkurve after evaluation of the parking lot 10 in relation to the stopped vehicle in position 1e is calculated on the basis of which the parking operation should proceed, but also the compliance with the Einparkbahnkurve turn, as above for the detection and recognition of the parking lot 10 explained, monitored or recorded. In case of any deviations from the optimal parking track or Einparkbahnkurve turn corresponding countermeasures could then be displayed to the driver and / or be compensated by corresponding automatically controlled steering movements.

Introduced the potential parking lot 10 to no positive rating, so to a parking lot of sufficient size and positivity, so the procedure, as by position 1f indicated to be continued to a new parking space and potential parking 10 find.

The In this case, the procedure may be characterized by events such as, exceeding a predetermined Timeouts, an action by the driver or passenger, for example Push of a button, passing the predetermined speed threshold, etc. are stopped.

In 2 is the time course of the signal path at any vehicle position 1a to 1f described when a transmitted ultrasonic signal 15 on an object 11 For example, vehicle, in particular adjacent vehicle side of a parked vehicle within the range of, for example, five meters impinges. Because of the vehicle sensor 13a at a time t _send the signal 15 has been sent out and the vehicle continues to move in the search for a parking space, can be from the sensor 13 _receiving signals at time t only 17 which are received by the object 11 were reflected at a corresponding angle. He did neuter distance 3 therefore does not correspond to half the signal propagation time of the signals 15 and 17 but is shorter according to the triangle angle (height of the triangle out 15 . 17 and path between t _send and t _reception ). Will no signal within a predetermined time t _max 17 receive, this means that there is no object 11 within range of the ultrasonic sensor.

As apparent from the above explanations, the lateral distance measurement is 3a to 3f in 1 only ideellerweise shown as perpendicular to the direction of travel and runs in detail after the in 2 however, excessive deviations shown. These deviations can be included in the evaluation by corresponding geometric methods or predefined correction values calculated therefrom as a function of different vehicle speeds and signal propagation times in order to reduce measurement errors.

Became a potential parking lot 10 scanned in the evaluation or evaluation in sufficient quality and certainty, for which, of course, test values or thresholds can be used, so is a parking lot 10 with sufficient security to initiate parking as explained above. Of course, it is always possible for a driver for safety reasons to intervene in the parking process. In addition, it is conceivable for the driver to also influence or cancel the result of the parking space recognition and, for example, to carry out a parking process, preferably supported by the system, despite a parking space which is not recognized in sufficient quality.

1a

position

1b

position

1c

position

1d

position

1e

position

1f

position

3

(Minimum) Distance between vehicle and object

3a

sensor signal

3b

sensor signal

3c

sensor signal

3d

sensor signal

3e

sensor signal

3f

sensor signal

5

line (parked cars in front of parking)

5a

vertex (Front bumper the last car)

7

line (Edging)

9

line (parking cars after parking)

9a

vertex (rear bumper the first car)

10

parking lot

11

object

13

sensor

t _SEND

time of the sensor when sending

t _RECEPTION

time of the sensor when receiving

t _MAX

maximum time for the receiving

15

emitted sensor signal

17

reflected sensor signal

Claims (9)

A method for detecting a parking space for a vehicle, a) in which by means of at least one arranged on a vehicle transmitting and receiving device while driving laterally from the vehicle sensor signals ( 15 ), b) the signals reflected thereby ( 17 ) and c) from the signal transit time and the vehicle movement information about the length and lateral extent of the parking lot ( 10 ) be determined. Method according to claim 1, characterized in that as sensor signals ( 15 . 17 ) Ultrasonic signals are sent and received. Method according to claim 1 or 2, characterized in that the sensor signals ( 15 . 17 ) are sent cyclically and received. Method according to one of the preceding claims, characterized in that signals ( 17 ) are evaluated only above a predetermined threshold for signal strength in terms of signal propagation time. Method according to claim 4, characterized in that that the predetermined threshold of the vehicle speed dependent is. Method according to one of the preceding claims, characterized characterized in that the method for parking recognition automatically started when falling below a predetermined vehicle speed becomes. Method according to one of the preceding claims, characterized in that the parking of the vehicle in the determined parking lot ( 10 ) by means of a parking curve calculated as a function of the determined parking space. A method according to claim 7, characterized in that for calculating the Einparkbahnkurve at least a forward and at least one backward movement are included to the parking lot ( 10 ) optimally exploit. A method according to claim 8 or 9, characterized characterized in that the parking along the parking track by means of an automatically controlled steering movement takes place.