CN113380068A - Parking space generation method based on description of obstacle outline - Google Patents

Abstract

The invention discloses a parking space generation method based on obstacle outline description, and relates to the technical field of parking spaces. The method is based on ultrasonic waves, and an envelope expression capable of describing the actual profile of the side barrier is obtained after an echo curve is processed; and obtaining reasonable parking space boundary points based on the profile.

Description

Parking space generation method based on description of obstacle outline

Technical Field

The invention belongs to the technical field of parking spaces, and particularly relates to a parking space generation method based on obstacle outline description.

Background

Along with the increasing demand of the market for the functions of the vehicle-mounted automatic parking system, the performance requirements of the automatic parking system are also improved, and for the ultrasonic parking system market, the requirements of customers on the accuracy and precision of side radar parking space identification are also continuously improved. On the basis of the existing hardware, a parking space positioning software algorithm capable of effectively improving the indexes is designed, accurate parking space positioning parameters are provided for customers, and the method is a necessary condition of a high-performance automatic parking system and one of the current popular research directions. In order to achieve the purpose of accurately positioning the angular point position of the parking space by using ultrasonic waves, the key point is to accurately describe the outline of the barrier forming the parking space.

In the first prior art, an automatic parking system senses by using an ultrasonic sensor, and uses the position of the ultrasonic sensor under a global coordinate system as a mark passing through a side obstacle when the ultrasonic echo distance has jump change when an obstacle vehicle is detected, and further calculates the position of a boundary characteristic point of the side obstacle under the coordinate system, so as to describe a parking space formed by the obstacle; and determining that the boundary point of the determined obstacle has transverse and lateral deviation from the boundary point of the reasonable parking space, so that the positioning of the whole parking space has deviation, or the reasonable parking space is not released, and if the road edge is detected, the parking space depth does not serve as the parking space to be released under the condition that the threshold value is not met. The defect of parking space positioning can directly cause unreasonable subsequent path planning, and finally the parking effect is not ideal.

In a second prior art scheme, after detecting an echo sudden change, firstly recording a boundary point a1 in the first scheme, when the vehicle continues to move forward until the echo distance is stabilized within a certain range, taking a median of the echo distance in the range as a lateral distance of the boundary point a2 in the second scheme to obtain a ordinate of a2 in a coordinate system, and taking an abscissa of a1 as an ordinate of a2, as shown in fig. 1 and 2, determining the position of the boundary point a2, thereby determining the parking space position; because the outline of real vehicle is not all the rectangle, and the outline cross section at car and SUV turning is mostly circular arc or oval arc line, and freight train turning profile cross section is mostly fillet rectangle, and the ultrasonic wave has the beam angle, consequently there is longitudinal deviation in the back wave point that obtains according to technique two and the boundary line of real outline, and the length of real parking stall can be shortened to this deviation, leads to the path planning degree of difficulty to rise to probably lead to the parking stall that calculates the reacing to be less than can release the parking stall threshold value, finally lead to not releasing this parking stall.

Disclosure of Invention

The invention aims to provide a parking space generation method based on obstacle outline description so as to solve the problems.

In order to solve the technical problems, the invention is realized by the following technical scheme:

the invention relates to a parking space generation method based on the description of an obstacle outline, which comprises the following steps:

stp1, constructing a vehicle kinematic model, further obtaining the specific position of the real-time echo point A in a coordinate system through geometric calculation, namely the coordinates (X2, Y2) of the echo point A, and simultaneously collecting an echo point set { A (X2, Y2) } of the echo point A obtained when the vehicle passes by the side;

stp2, carrying out nonlinear processing on the echo point set by software to obtain a curve expression F (x), wherein the curve expression F (x) is a mathematical model of the obstacle contour line obtained by ultrasonic waves;

stp3, calculating an expression H (x) for describing the outline at the corner of the vehicle according to the actual outline size of the vehicle;

stp4, taking F (x) and H (x) as training samples to construct mapping to obtain an expression L (x);

stp5, repeating step Stp1 and step Stp2, obtaining a new echo point set { a ' (X2, Y2) } of the echo point a from step Stp1, and generating a new curve expression F ' (X) from step Stp2 and the echo point set { a ' (X2, Y2) };

stp6, taking F '(x) as a new input of an expression L (x), obtaining an actual outline expression H' (x) of the obstacle;

stp7, making an asymptote according to an expression H' (x) to obtain an intersection point B, and taking the point B as an obstacle boundary point to construct a parking space.

The invention has the following beneficial effects:

the method is based on ultrasonic waves, and an envelope expression capable of describing the actual profile of the side barrier is obtained after an echo curve is processed; and obtaining reasonable parking space boundary points based on the profile.

Of course, it is not necessary for any product in which the invention is practiced to achieve all of the above-described advantages at the same time.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a flow chart of a parking space generation method of the present invention;

FIG. 2 is a schematic diagram of the position of the echo point A in the coordinate system according to the present invention;

FIG. 3 is a diagram illustrating the mapping construction of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it is to be understood that the terms "opening," "upper," "lower," "thickness," "top," "middle," "length," "inner," "peripheral," and the like are used in an orientation or positional relationship that is merely for convenience in describing and simplifying the description, and do not indicate or imply that the referenced components or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus are not to be considered as limiting the present invention.

Referring to fig. 1-3, the present invention is a method for generating parking spaces based on the outline of obstacles, comprising:

stp1, constructing a vehicle kinematic model, further obtaining the specific position of the real-time echo point A in a coordinate system through geometric calculation, namely the coordinates (X2, Y2) of the echo point A, and simultaneously collecting an echo point set { A (X2, Y2) } of the echo point A obtained when the vehicle passes by the side;

stp2, carrying out nonlinear processing on the echo point set by software to obtain a curve expression F (x), wherein the curve expression F (x) is a mathematical model of the obstacle contour line obtained by ultrasonic waves;

stp3, calculating an expression H (x) for describing the outline at the corner of the vehicle according to the actual outline size of the vehicle;

stp4, taking F (x) and H (x) as training samples to construct mapping to obtain an expression L (x);

stp5, repeating step Stp1 and step Stp2, obtaining a new echo point set { a ' (X2, Y2) } of the echo point a from step Stp1, and generating a new curve expression F ' (X) from step Stp2 and the echo point set { a ' (X2, Y2) };

stp6, taking F '(x) as a new input of an expression L (x), obtaining an actual outline expression H' (x) of the obstacle;

stp7, making an asymptote according to an expression H' (x) to obtain an intersection point B, and taking the point B as an obstacle boundary point to construct a parking space.

In the description herein, references to the description of "one embodiment," "an example," "a specific example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The preferred embodiments of the invention disclosed above are intended to be illustrative only. The preferred embodiments are not intended to be exhaustive or to limit the invention to the precise embodiments disclosed. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and the practical application, to thereby enable others skilled in the art to best utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims (1)

1. A parking space generation method based on obstacle outline description is characterized by comprising the following steps:

stp1, constructing a vehicle kinematic model, and further geometrically calculating to obtain the specific position of the real-time echo point A in the coordinate system, namely the coordinate (X) of the echo point A₂，Y₂) And simultaneously acquiring an echo point set { A (X) of echo points A obtained when the vehicle passes by the side edge₂，Y₂)}；

Stp2, carrying out nonlinear processing on the echo point set by software to obtain a curve expression F (x), wherein the curve expression F (x) is a mathematical model of the obstacle contour line obtained by ultrasonic waves;

stp3, calculating an expression H (x) for describing the outline at the corner of the vehicle according to the actual outline size of the vehicle;

stp4, taking F (x) and H (x) as training samples to construct mapping to obtain an expression L (x);

step Stp5, step Stp1 and step Stp2 are repeated, and a new echo point set { a '(X') of echo points a is obtained in step Stp1₂，Y₂) And from step Stp2 and set of echo points { A' (X)₂，Y₂) Generating a new curve expression F' (x);

stp6, taking F '(x) as a new input of an expression L (x), obtaining an actual outline expression H' (x) of the obstacle;

stp7, making an asymptote according to an expression H' (x) to obtain an intersection point B, and taking the point B as an obstacle boundary point to construct a parking space.

Images