1. A GPS-based vehicle turning radius measurement method is characterized by comprising the following steps:

driving a vehicle to be tested, which is provided with a vehicle-mounted GPS, to continuously run under a preset steering wheel corner, wherein the steering wheel corner is larger than 0 degree;

receiving current steering wheel corner information of a vehicle, and respectively collecting coordinate information sent by a vehicle-mounted GPS for three times in the continuous running process of the vehicle to be detected;

measuring and calculating the turning radius of the vehicle according to the current steering wheel corner information and coordinate information and by combining a preset distance formula and a triangle included angle formula;

changing the steering wheel angle of the vehicle to be measured, and measuring and calculating the turning radius of the vehicle under different steering wheel angles according to the mode;

and outputting a vehicle turning radius test report according to a preset report format.

2. The GPS-based vehicle turning radius measurement method according to claim 1, wherein the calculating of the vehicle turning radius according to the current steering wheel angle information and coordinate information in combination with a preset distance formula and a triangle included angle formula specifically comprises:

a, B, C coordinate information (X) of three position points are collected in sequence in the continuous running process of the vehicle to be tested_A,Y_A),(X_B,Y_B),(X_C,Y_C)；

According to a preset distance formula between two points { (x)₂-x₁)²+(y₂-y₁)²1/2, respectively finding out the lengths of a line segment connected with the two points AB, a line segment connected with the two points BC and a line segment connected with the two points AC;

according to a preset triangle included angle formula beta ═ arccos (b)²+c²-a²) 2bc, calculating to obtain [ ABC ];

setting the middle point of an arc line of a vehicle to be detected running at the current steering wheel angle as O, the middle point of a line segment connected with two points AB as D, and the middle point of a line segment connected with two points BC as E to obtain < DBO + < EBO >;

and measuring and calculating the vehicle turning radius according to the vehicle turning radius r which is OB which is DB/cos which is EB/cos which is EBO.

3. A GPS-based vehicle turning radius measurement system, comprising: the system comprises an upper computer controller, a power supply module, a vehicle to be tested, a vehicle-mounted GPS and a GPS base station;

the power supply module is used for providing a working power supply for the upper computer controller and the vehicle-mounted GPS; the vehicle-mounted GPS is used for testing the position coordinates of a vehicle to be tested in the running process under the current steering wheel corner; the GPS base station is used for providing coordinate reference origin information for the vehicle-mounted GPS;

the upper computer controller is configured to execute the vehicle turning radius measurement method according to claim 1 or 2.

Background

With the continuous increase of automobile reserves and the popularization of intelligent automobile concepts in China, the auxiliary driving function gradually becomes a standard configuration. And the turning radius of the vehicle under different steering wheel angles is an indispensable judgment parameter in the development of the auxiliary driving function. The method plays a crucial role in function development and road curvature radius, so that the accuracy of vehicle turning radius measurement is particularly important.

At present, in the related art, the following schemes are mainly used for obtaining the turning radius of a vehicle under different steering wheel turning angles:

(1) vehicle information is collected through an Electronic Stability Program (ESP), and the turning radius of the vehicle is obtained through calculation of the ESP; the solution relies on calibration and experience of the EPS supplier.

(2) Converting steering wheel angle to wheel angle by measurement or vehicle transmission ratio; then, according to the Ackerman model, the turning radius of the vehicle under different steering wheel corners is obtained through calculation; the measuring method of the scheme relates to a transmission ratio and an Ackerman model, and is used for measuring and calculating the chain length and lower in measuring precision.

(3) And driving the vehicle to be measured to run in the open field marked by the marking line, and reading the wheel traces according to the field mark scales to finish measuring the turning radius of the vehicle under different steering wheel corners. The scheme has great requirements on the space of the site, and the work difficulty of site marking is great. The vehicle needs to be driven to align with the site marking line in the measuring process, the requirement on a driver is high, the whole testing process is complex, the operation difficulty is high, and the testing precision is not high.

Disclosure of Invention

In view of the above, the present invention aims to provide a vehicle turning radius measuring method and system based on GPS to overcome the shortcomings of the existing solutions.

The technical scheme adopted by the invention is as follows:

a GPS-based vehicle turning radius measurement method, comprising:

driving a vehicle to be tested, which is provided with a vehicle-mounted GPS, to continuously run under a preset steering wheel corner, wherein the steering wheel corner is larger than 0 degree;

receiving current steering wheel corner information of a vehicle, and respectively collecting coordinate information sent by a vehicle-mounted GPS for three times in the continuous running process of the vehicle to be detected;

measuring and calculating the turning radius of the vehicle according to the current steering wheel corner information and coordinate information and by combining a preset distance formula and a triangle included angle formula;

changing the steering wheel angle of the vehicle to be measured, and measuring and calculating the turning radius of the vehicle under different steering wheel angles according to the mode;

and outputting a vehicle turning radius test report according to a preset report format.

In at least one possible implementation manner, the calculating the turning radius of the vehicle according to the current steering wheel angle information and the coordinate information and by combining a preset distance formula and a preset triangle included angle formula specifically includes:

a, B, C coordinate information (X) of three position points are collected in sequence in the continuous running process of the vehicle to be tested_A,Y_A),(X_B,Y_B),(X_C,Y_C)；

According to a preset distance formula between two points { (x)₂-x₁)²+(y₂-y₁)²1/2, respectively finding out the lengths of a line segment connected with the two points AB, a line segment connected with the two points BC and a line segment connected with the two points AC;

according to a preset triangle included angle formula beta ═ arccos (b)²+c²-a²) 2bc, calculating to obtain [ ABC ];

setting the middle point of an arc line of a vehicle to be detected running at the current steering wheel angle as O, the middle point of a line segment connected with two points AB as D, and the middle point of a line segment connected with two points BC as E to obtain < DBO + < EBO >;

and measuring and calculating the vehicle turning radius according to the vehicle turning radius r which is OB which is DB/cos which is EB/cos which is EBO.

In addition, the present invention also provides a GPS-based vehicle turning radius measuring system, including: the system comprises an upper computer controller, a power supply module, a vehicle to be tested, a vehicle-mounted GPS and a GPS base station;

the power supply module is used for providing a working power supply for the upper computer controller and the vehicle-mounted GPS; the vehicle-mounted GPS is used for testing the position coordinates of a vehicle to be tested in the running process under the current steering wheel corner; the GPS base station is used for providing coordinate reference origin information for the vehicle-mounted GPS;

the upper computer controller is configured to execute the vehicle turning radius measurement method according to claim 1 or 2.

The invention has the conception that the measurement precision is controlled by the GPS data, and particularly, when a vehicle runs at a certain set corner, the turning radius at the corner of the current steering wheel can be accurately measured and calculated based on a distance algorithm and a triangular included angle algorithm by only acquiring the GPS data three times, so that a measurement report is convenient and easy to obtain, the manpower and material resources are greatly saved, and the test efficiency is improved. In addition, the scheme of the invention has strong adaptability, can finish measurement in small-size fields such as roads, parking lots and the like, and solves the problem that the traditional measurement requires a large-size measurement field; the method does not need a vehicle dynamics model, is simple in test operation, and gets rid of the dependence of the traditional method for calculating the turning radius of the vehicle on the vehicle model.

Drawings

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described with reference to the accompanying drawings, in which:

FIG. 1 is a flow chart of a GPS-based vehicle turning radius measurement method provided by an embodiment of the present invention;

FIG. 2 is a schematic view of a vehicle turning radius measurement provided by an embodiment of the present invention;

FIG. 3 is a schematic diagram of a GPS-based vehicle turning radius measurement system provided by an embodiment of the present invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative only and should not be construed as limiting the invention.

The invention provides an embodiment of a vehicle turning radius measuring method based on GPS, which specifically comprises the following steps as shown in FIG. 1:

step S1, driving a vehicle to be tested, which is provided with a vehicle-mounted GPS, to continuously run under a preset steering wheel corner, wherein the steering wheel corner is larger than 0 degree;

s2, receiving current steering wheel corner information of the vehicle, and respectively collecting coordinate information sent by the vehicle-mounted GPS for three times in the continuous driving process of the vehicle to be detected;

step S3, according to the current steering wheel corner information and coordinate information, and in combination with a preset distance formula and a triangle included angle formula, measuring and calculating the turning radius of the vehicle;

s4, changing the steering wheel angle of the vehicle to be measured, and measuring and calculating the turning radius of the vehicle under different steering wheel angles according to the method;

and step S5, outputting a vehicle turning radius test report according to a preset report format.

In practical operation, as shown in fig. 2, the calculating the turning radius of the vehicle according to the current steering wheel angle information and the coordinate information and by combining a preset distance formula and a preset triangle included angle formula specifically includes:

a, B, C coordinate information (X) of three position points are collected in sequence in the continuous running process of the vehicle to be tested_A,Y_A),(X_B,Y_B),(X_C,Y_C)；

According to a preset distance formula between two points { (x)₂-x₁)²+(y₂-y₁)²1/2, respectively finding out the lengths of a line segment connected with the two points AB, a line segment connected with the two points BC and a line segment connected with the two points AC; it is emphasized that the corner mark 1/2 herein refers to the power 1/2 (the root of the square), i.e., pair { (x)₂-x₁)²+(y₂-y₁)²The whole is squared.

According to a preset triangle included angle formula beta＝arccos(b²+c²-a²) 2bc, calculating to obtain [ ABC ];

setting the middle point of an arc line of a vehicle to be detected running at the current steering wheel angle as O, the middle point of a line segment connected with two points AB as D, and the middle point of a line segment connected with two points BC as E to obtain < DBO + < EBO >;

and measuring and calculating the vehicle turning radius according to the vehicle turning radius r which is OB which is DB/cos which is EB/cos which is EBO.

Correspondingly, the invention also provides a vehicle turning radius measuring system based on GPS, as shown in FIG. 3, which mainly comprises: the device comprises an upper computer controller, a power supply module, a vehicle to be tested, a vehicle-mounted GPS and a GPS base station.

Specifically, the upper computer controller is configured to perform unified management and operation on the measurement system, for example, manage running software of the entire test system, and may be implemented by a specific measurement and control module in the figure, and automatically output a test report according to a report format preset by a tester. Specifically, the steering wheel angle information and the vehicle-mounted GPS information of the vehicle to be tested can be collected, corresponding vehicle turning radius data are calculated and output through the measurement and control module according to the embodiments, and finally, an automatic test report is output according to the test data; the power supply module is used for providing a working power supply for components such as an upper computer controller, a vehicle-mounted GPS and the like; the vehicle to be tested is the vehicle for testing the turning radius under different steering wheel corners; the vehicle-mounted GPS is used for testing the coordinates of the vehicle and the coordinates of the position of the vehicle under different steering wheel corners, and preferably, as shown in the figure, a special vehicle-mounted GPS for testing can be adopted; the GPS base station is used for providing coordinate reference origin information for the vehicle-mounted GPS.

In summary, the present invention is conceived to control the measurement accuracy by GPS data, and specifically, when a vehicle is traveling at a certain set corner, the present steering wheel corner turning radius can be accurately measured based on a distance algorithm and a triangle included angle algorithm by acquiring GPS data three times, so that a measurement report is convenient and easy to obtain, manpower and material resources are greatly saved, and the test efficiency is improved. In addition, the scheme of the invention has strong adaptability, can finish measurement in small-size fields such as roads, parking lots and the like, and solves the problem that the traditional measurement requires a large-size measurement field; the method does not need a vehicle dynamics model, is simple in test operation, and gets rid of the dependence of the traditional method for calculating the turning radius of the vehicle on the vehicle model.

In the embodiments of the present invention, "at least one" means one or more, "a plurality" means two or more. "and/or" describes the association relationship of the associated objects, and means that there may be three relationships, for example, a and/or B, and may mean that a exists alone, a and B exist simultaneously, and B exists alone. Wherein A and B can be singular or plural. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship. "at least one of the following" and similar expressions refer to any combination of these items, including any combination of singular or plural items. For example, at least one of a, b, and c may represent: a, b, c, a and b, a and c, b and c or a and b and c, wherein a, b and c can be single or multiple.

The structure, features and effects of the present invention have been described in detail with reference to the embodiments shown in the drawings, but the above embodiments are merely preferred embodiments of the present invention, and it should be understood that technical features related to the above embodiments and preferred modes thereof can be reasonably combined and configured into various equivalent schemes by those skilled in the art without departing from and changing the design idea and technical effects of the present invention; therefore, the invention is not limited to the embodiments shown in the drawings, and all the modifications and equivalent embodiments that can be made according to the idea of the invention are within the scope of the invention as long as they are not beyond the spirit of the description and the drawings.