KR20130057893A

KR20130057893A - Method for producing driving path using clothoid curve and computer readable recording medium recording computer program

Info

Publication number: KR20130057893A
Application number: KR1020110123864A
Authority: KR
Inventors: 이철하
Original assignee: 현대자동차주식회사
Priority date: 2011-11-24
Filing date: 2011-11-24
Publication date: 2013-06-03

Abstract

PURPOSE: A travelling route generating method using a clothoid curve and a recording medium capable of being read with a computer in which a program for performing the same is installed are provided to generate a travelling route using the clothoid curve, thereby improving the ride comfort of a passenger. CONSTITUTION: A travelling route generating method using a clothoid curve comprises: a step(S100) of obtaining the data of discrete coordinates of an actual path; a step(S200) of calculating the curvature on the positions of the obtained coordinates; a step(S300) of gathering sections of which curvature is similar and sorting the sections into a straight section, a clothoid section, and a circle section; and a step(S400) of generating the clothoid curve of the clothoid section using a distance between the straight and circle sections and the diameter of the circle section. [Reference numerals] (AA) Start; (BB) End; (S100) Measure the coordinates of an actual path; (S200) Calculate the curvature between adjacent coordinates; (S300) Sort a straight section, a circle section, and a clothoid section; (S400) Complete a clothoid curve; (S500) Complete a path

Description

METHOD FOR PRODUCING DRIVING PATH USING CLOTHOID CURVE AND COMPUTER READABLE RECORDING MEDIUM RECORDING COMPUTER PROGRAM}

The present invention generates a driving route using a straight line, a circle, and a closed curve smoothly connecting the straight line and the circle, so that the vehicle can be smoothly steered and the ride route using the closed curve to improve the passenger's riding comfort. It relates to a production method.

In the case of a conventional vehicle, the curve of a map road mounted on a navigation has a lot of difference from the actual one, and there is a heterogeneity. The ride comfort is bound to improve. In addition, even when designing the curvature of the road as a general road, there was a lack of technology for automatically generating a map with such a smooth real path.

The present invention relates to a technology for producing a map required for autonomous driving of a vehicle equipped with GPS or DGPS. Differential GPS (DGPS) is a relative positioning method of GPS surveying that corrects elements that cause errors using a known reference point coordinate, and obtains a more accurate position by reducing errors as much as possible.

DGPS is a device that can get the current position more precisely than GPS. Therefore, by providing a map of coordinate values of a constant interval to a vehicle equipped with DGPS, the coordinate values can be followed by an error within a few cm. In addition, in order to make a map, first, approximate coordinate values of a section to be produced are required. This coordinate can be measured by manually driving a vehicle equipped with DGPS. The measured coordinate values eliminate and soften errors caused by humans and equipment through Curve Fitting. Finally, the map is completed by allowing coordinate values to be generated at regular distances. To date, all of these tasks have been done by hand.

On the other hand, since the centrifugal force is proportional to the curvature of the map, the curvature of the map affects the ride comfort of the occupant. Therefore, if the map is created to have a smooth curvature, the steering can be smooth and the occupant can feel comfortable. In the present invention, in order to automatically generate a map having a smooth curvature, a spiral is used to constantly change the curvature change between a straight line, a circle, and a space therebetween. The spiral curve was used as a closed curve, which is a curve in which the curvature increases constantly in proportion to the length of the curve.

The closoid curve is a type of curve having a property of increasing curvature (reducing radius of curvature) in proportion to the curve length, and is used as a linear curve of a relaxation curve of a highway. When the curve length is L and the radius of curvature R is RL = A ² (constant). As A (parameter) becomes large, the curvature of the curve becomes gentle with respect to the curve length L. It is a kind of spiral curve, used not only as a relaxation curve between a straight line and a circle, but also as an element of a linear design.

Therefore, there is a need for a method of automatically generating a smooth and realistic route map to which the clothoid curve is applied through each coordinate value data of a road to be actually used.

It should be understood that the foregoing description of the background art is merely for the purpose of promoting an understanding of the background of the present invention and is not to be construed as an admission that the prior art is known to those skilled in the art.

The present invention has been proposed to solve the above problems, and by generating a driving route using a straight line, a circle, and a closet curve smoothly connecting the straight line and the circle, smooth steering of the vehicle is possible, and the ride comfort of the passenger is improved. It is an object of the present invention to provide a method for generating a driving route using a clausoid curve.

In order to achieve the above object, a method for generating a driving route using a clothoid curve according to the present invention includes: a collecting step of obtaining discrete coordinate value data of an actual path; Calculating a curvature in the obtained coordinate values; A grouping step of collecting sections having similar curvatures and dividing them into straight sections, closed sections, and round sections; And a connecting step of generating a close curve of the closet section through the distance between the straight section and the round section and the radius of the round section.

In the connecting step, each coordinate (X, Y) constituting the clausoid curve may be calculated using the radius of curvature R at the corresponding coordinate.

In the connecting step, the clathoid curve may be obtained using the following equation regarding the coordinates of any one point constituting the cloth curve and the following equation about the slope of the tangent tangent to the point.

In the connecting step, by generating a closoid curve using the coordinates of the point where the straight section ends, the closed section connecting the spaced straight sections and the original sections can be obtained.

In the connecting step, a closoid curve may be generated by using a coordinate of an arbitrary point as an origin, and a parallel movement thereof may be obtained by connecting the spaced straight sections and the closed sections.

On the other hand, a computer-readable recording medium having a program recorded thereon that allows the driving path generation method using the clausoid curve to be executed by a computer is obtained by obtaining discrete coordinate data of the actual path from the input data. Step S100; Calculating a curvature in the obtained coordinate values (S200); A grouping step (S300) of collecting sections having similar curvatures and dividing them into straight sections, closed sections, and original sections; And a connecting step (S400) of generating a close curve of the closed section through the distance between the straight section and the round section and the radius of the round section (S400).

According to the method of generating a driving route using the clausoid curve having the above-described structure, a smooth steering of the vehicle is possible by generating the driving route using a straight line, a circle, and a closet curve smoothly connecting the straight line and the circle. It is possible to improve the ride comfort of the occupant.

1 is a flowchart of a method for generating a driving route using a clothoid curve according to an exemplary embodiment of the present invention.
FIG. 2 is a view illustrating a process of generating a route according to a driving route generating method using a closoid curve of the present invention shown in FIG. 1.
FIG. 3 is a view illustrating a process of generating a closesoid curve during generation of a route according to a driving route generation method using the closesoid curve of the present invention shown in FIG. 1;

Hereinafter, with reference to the accompanying drawings looks at with respect to the driving path generation method using a clausoid curve in accordance with a preferred embodiment of the present invention.

1 is a flowchart of a method for generating a driving route using a clausoid curve according to an exemplary embodiment of the present invention. The method for generating a driving route using a clausoid curve according to an embodiment of the present invention obtains discrete coordinate value data of an actual route. Collecting step (S100); Calculating a curvature in the obtained coordinate values (S200); A grouping step (S300) of collecting sections having similar curvatures and dividing them into straight sections, closed sections, and original sections; And a connecting step (S400) of generating a close curve of the closet section through the distance between the straight section and the round section and the radius of the round section.

The present invention is to generate a smooth and perfect path by automatically calculating the road which is the driving route of the vehicle during the production of a map mounted on the navigation of the vehicle or the production of a map used in the production of a map or an actual road design for the automatic driving device. It's about how to make that happen. This method receives the measured coordinate values and can derive the actual path through the program implemented.

To do this, we first drive a real vehicle equipped with GPS or DGPS equipment and obtain discrete coordinate values for each route. Of course, this may be learned as separate provided data.

Then, the acquired coordinates are input to obtain discrete coordinate value data of the actual path.

The curvature between neighboring coordinates is calculated based on the obtained coordinate values. The following formula can be used when calculating curvature.

The calculation of curvature calculates the curvature by applying the first and second differential approximation equations using arbitrary one coordinates and two neighboring coordinates. In the above formula, the curvature p _s0 at the coordinates (x _s0 , y _s0 ) is obtained.

After obtaining the curvature as described above, the sections having similar curvatures are collected and divided into straight sections, clothoid sections, and circle sections. Then, the closed curve is generated through the distance between the straight section and the circle section and the radius of the circle section, and the path generation is completed by connecting each straight section, the close section and the round section. Will be.

FIG. 2 is a view illustrating a process of generating a route according to a driving route generation method using the closoid curve of the present invention shown in FIG. 1, and as shown in (a), each coordinate value is derived, and (b) Obtain the curvature and divide it into straight section and circle section, and define the close section that connects the straight section and the circle section as shown in (c), and find the closet curve as shown in (d). Finally, the obtained path has a form in which the curvature continues linearly as shown in (e), thereby providing the driver with a constant slope and a smooth slope, thereby improving driving and riding sensations.

Meanwhile, FIG. 3 is a view illustrating a process of generating a closoid curve during generation of a path according to the driving route generation method using the closoid curve of the present invention shown in FIG. 1, wherein the connecting step (S400) is a claw. Each coordinate (X, Y) constituting the Soid curve may be calculated using the radius of curvature R at the coordinate.

More specifically, the connecting step (S400), by using the following equation for the coordinates of any one point constituting the closing curve and the slope of the tangent tangent to the point by using the following equation You can get it.

As can be seen from the above equation, if the radius of a circle contacting a point (X, Y) on the clausoid curve is R and the length of the curve from the origin to (X, Y) is L, then (X, Y) is Derived as In addition, the angle between the tangent line and the axis in contact with the point on the clausoid curve is also derived as in the above equation.

Referring to FIG. 3, when the point where the cladesoid curve meets the circle is (a, b) and the angle of the tangent tangent to the point is T, the radius of curvature R is determined at (a, b). From the third formula of 2, L can be found in terms of T. And by substituting L and R in the second formula of Equation 2, the Y coordinate b can be found as an expression for T. In addition, the Y coordinate b whose angle of tangent on the circle is T can be obtained as a function of T through the derivative.

Then, b and T can be found by using the same Y-coordinates obtained from the closet curve and the circle. Since L is a function of T, we know the value of L, and since R is the given value, we can determine the Closoid curve.

The calculated Closoid curve starts at the origin and passes through (aK, b). Therefore, by closing the curve in the X-axis direction by K, it is possible to obtain a clothoid curve passing through (K, 0) and (a, b).

On the other hand, in the connection step (S400), by generating a Closoid curve by using the coordinates of the point where the straight section ends, it may be possible to obtain a closed section connecting the spaced straight section and the original section, arbitrary point Closoid curves may be generated by using the coordinates of, and parallel movements may be performed to obtain a closoid section connecting the spaced straight sections and the original sections.

Therefore, according to the method of generating a driving route using the clausoid curve having the above-described structure, a smooth steering of the vehicle is generated by generating a driving route using a straight line, a circle, and a closet curve smoothly connecting the straight line and the circle. This is possible, and the ride comfort of the occupant can be improved.

A computer readable recording medium having a program recorded thereon that allows a driving path generation method using a clausoid curve to be executed by a computer includes: a collection step of obtaining discretized coordinate value data of an actual path from input data; (S100); Calculating a curvature in the obtained coordinate values (S200); A grouping step (S300) of collecting sections having similar curvatures and dividing them into straight sections, closed sections, and original sections; And a connecting step (S400) of generating a close curve of the closed section through the distance between the straight section and the round section and the radius of the round section (S400). It can be a medium.

While the present invention has been particularly shown and described with reference to specific embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the following claims It will be apparent to those of ordinary skill in the art.

S100: Acquisition step S200: Computation step
S300: grouping step S400: operation step

Claims

A collection step (S100) of obtaining discretized coordinate value data of a real path;
Calculating a curvature in the obtained coordinate values (S200);
A grouping step (S300) of collecting sections having similar curvatures and dividing them into straight sections, closed sections, and original sections; And
And a connecting step (S400) of generating a close curve of the closed section through the distance between the straight section and the closed circle section and the radius of the round section (S400).

The method according to claim 1,
In the connecting step (S400), each coordinate (X, Y) constituting the Closoid curve is calculated using the radius of curvature R in the coordinates, characterized in that the driving path generation method using a Closoid curve.

The method according to claim 1,
The connecting step (S400), characterized in that to obtain a clausoid curve using the following equation for the coordinates of any one point constituting the Closoid curve and the following equation for the slope of the tangent tangent to the point A driving route generation method using a closeoid curve.

The method according to claim 1,
The connecting step (S400), by generating a Closoid curve with the coordinates of the end point of the straight section as a starting point Closoid curve characterized in that to obtain a closed section connecting the spaced straight section and the original section How to create a driving route using.

The method according to claim 1,
The connecting step (S400), by generating a Closoid curve with the coordinates of any point as the origin, and by moving the parallel to obtain a Closoid section connecting the spaced straight section and the original section How to create a driving route using a curve.

A computer-readable recording medium having recorded thereon a program for executing a driving route generation method using the clausoid curve of claim 1,
A collecting step (S100) of obtaining discretized coordinate value data of an actual path from the input data;
Calculating a curvature in the obtained coordinate values (S200);
A grouping step (S300) of collecting sections having similar curvatures and dividing them into straight sections, closed sections, and original sections; And
A connection step (S400) of generating a close curve of the closed section through the distance between the straight section and the round section and the radius of the round section (S400); a computer-readable recording medium on which a program for executing the computer is recorded .