Patent Description:
At present, a wheel positioning system has been widely applied to the technical field of automobile calibration. For example, the wheel positioning system may acquire a three-dimensional target assembled on a vehicle and performs calculation according to the position of the three-dimensional target, thereby achieving vehicle calibration. However, the technical problems that measurement calculation is few in dimension and calibration calculation is lower in precision are caused in the three-dimensional target adopting single target surface.

<CIT> and <CIT> disclose three-dimensional targets for calibration systems.

<CIT> and <CIT> disclose conventional wheel positioning systems and methods.

Purposes of embodiments of the present application are to provide a wheel positioning system, a wheel positioning method, by which the technical problem that the calibration calculation is lower in precision in the prior art may be solved.

An embodiment of the present application provides a wheel positioning system, including a three-dimensional target, an image acquisition device, and a processing system;
the three-dimensional target is attached to a wheel, the vision range of the image acquisition device faces the three-dimensional target, and the image acquisition device is electrically connected to the processing system;.

Optionally, the base body is of a stereoscopic blocky structure provided with multiple outer surfaces, wherein the outer surfaces of the base body are provided with the at least three target surfaces.

Optionally, the target surfaces are planes or curved surfaces.

Optionally, the at least three target surfaces are disposed at a preset angle.

Optionally, the target elements are geometric patterns concavely or convexly disposed on the target surfaces.

Optionally, one end surface of the base body is provided with a first target surface, the other end surface of the base body is provided with a second target surface, the base body extends outwards to form a convex part, and the convex part is provided with a third target surface, wherein the first target surface and the third target surface are disposed in parallel, and the second target surface is located between the first target surface and the third target surface.

Optionally, the first target surface and the third target surface face the same horizontal direction, and the first target surface and the second target surface are disposed at a preset angle.

Optionally, a mounting cavity is concavely disposed towards the inside of the base body from the second target surface, and a fixing hole which is through is disposed in the bottom of the mounting cavity.

Optionally, the base body is shaped like a step, the base body includes a first step, a second step, and a third step, an end surface of the first step is provided with a first target surface, an end surface of the second step is provided with a second target surface, and an end surface of the third step is provided with a third target surface.

Optionally, the base body includes a first wall body, a second wall body, and a third wall body, every two of the first wall body, the second wall body and the third wall body are perpendicular to each other to co-define a conical space, the side, facing the conical space, of the first wall body is provided with a first target surface, the side, facing the conical space, of the second wall body is provided with a second target surface, and the side, facing the conical space, of the second wall body is provided with a third target surface.

An exemplary wheel positioning system, includes a three-dimensional target, an image acquisition device, and a processing system;.

An embodiment of the present application provides a wheel positioning method, wherein the method includes:.

calculating at least two pieces of wheel positioning information according to the images of the target elements of at least two groups of calculation units, comparing whether the at least two pieces of wheel positioning information are consistent, and determining the position of the wheel according to the wheel positioning information if the at least two pieces of wheel positioning information are consistent.

An exemplary wheel positioning method includes: attaching a three-dimensional target to the outer surface of a wheel, wherein the three-dimensional target includes a base body; the base body is provided with at least three target surfaces, and the at least three target surfaces are all in different planes; and the at least three target surfaces are each provided with target elements, the spatial positional relationship between the target elements is known, and the geometric properties of the target elements are known;
acquiring images of the target elements of two of the target surfaces in the at least three target surfaces; and screening images of at least two of the target surfaces, and determining the position of the wheel according to the images of the at least two of the target surfaces.

Compared with the prior art, in the three-dimensional target in the present embodiments, the base body is provided with at least three target surfaces, the at least three target surfaces are all in different planes, and the target surfaces are provided with the target elements for calibration. Therefore, by using two target surfaces as a group, the at least three target surfaces can be configured into multiple groups, and calibration is performed according to the multiple groups of target surfaces, thus, the accuracy of calibration calculation can be improved. In addition, by comparing calibration parameters obtained by each group of target surfaces, it may be determined whether the three-dimensional target meets a demand on precise calibration, and thus, the invalid three-dimensional target may be replaced in time.

One or more embodiments are exemplarily described with figures in accompanying drawings corresponding to the embodiments, these exemplary descriptions do not constitute limitations on the embodiments, elements with the same reference numerals in the accompanying drawings denote similar elements, unless otherwise specified, the figures in the accompanying drawings are not limited in proportion.

In order to facilitate understanding the present application, the present application will be described in more detail below with reference to the accompanying drawings and specific embodiments. It needs to be noted that when one element is stated as "fixed to" another element, the element may be directly located on another element, or one or more centered elements may exist therebetween. When one element is stated as "connected to" another element, the element may be directly connected to another element, or one or more centered elements may exist therebetween. Directional or positional relationships indicated by terms such as "upper", "lower", "inner", "outer", "vertical", and "horizontal" used in the present application are directional or positional relationships based on the accompanying drawings, are merely intended to facilitate describing the present application and simplifying the description, rather than to indicate or imply that the appointed device or element has to be located in a specific direction or structured and operated in the specific direction so as not to be understood as restrictions on the present application.

Unless defined otherwise, all technical and scientific terms used the present description have the same meaning as commonly understood by those of ordinary skill in the art to which this technology belongs. The terms used in the description of the present application are merely for the purpose of describing specific embodiments, rather than to limit the present application. The term "and/or" used in the present description includes any or all of combinations of one or more listed relevant items.

In addition, the technical features related to the different embodiments, described as below, of the present application may be combined with one another as long as they are not conflictive.

With reference to <FIG>, an embodiment of the present application provides a three-dimensional target <NUM> with multiple surfaces. The three-dimensional target <NUM> may be applied to a wheel positioning system. For example, as shown in <FIG>, the wheel positioning system includes the three-dimensional target <NUM>, an image acquisition device <NUM> and a processing system <NUM>. The three-dimensional target <NUM> is attached to a wheel <NUM>, the vision range of the image acquisition device <NUM> faces the three-dimensional target <NUM>, and the image acquisition device <NUM> is electrically connected to the processing system <NUM>. The image acquisition device <NUM> acquires an image of the three-dimensional target <NUM> and feeds the image back to the processing system <NUM>, and the processing system <NUM> determines the position of the wheel <NUM> according to the image of the three-dimensional target <NUM>.

As shown in <FIG>, the three-dimensional target <NUM> includes a base body <NUM>. The base body <NUM> is shaped like a stereoscopic block provided with multiple outer surfaces, and optionally, the base body <NUM> is of a regular geometrical shape. The base body <NUM> is provided with at least three target surfaces, and the at least three target surfaces are all in different planes, wherein the outer surfaces of the base body <NUM> are provided with at least three target surfaces, and the at least three target surfaces are all in different planes. The at least three target surfaces are each provided with target elements <NUM>, the spatial positional relationship between the target elements <NUM> is known, and the geometric properties of the target elements <NUM> are known. For example, the target surfaces are disposed at a preset angle, and the target surfaces are provided with the target elements <NUM> configured to be subjected to image acquisition, wherein the target elements <NUM> are geometric patterns which are concavely or convexly disposed. In the present embodiment, the target elements <NUM> are round spots concavely disposed in the target surfaces.

In the present embodiment, the target surfaces on the three-dimensional target <NUM> are protruded outwards, image data may be easily acquired by the image acquisition device <NUM> from the target elements <NUM> located on the target surfaces, the at least three target surfaces may respectively face multiple directions, and the at least three target surfaces are all in different planes, so that the three-dimensional target <NUM> may adapt to multiple outer viewing angles, the image acquisition device <NUM> may conveniently acquire the image data, and the three-dimensional target <NUM> is wider in application range. For example, when the three-dimensional target <NUM> is fixed to a calibrated object, the situation that some of the target surfaces are shielded may occur, but some of the target surfaces may also be protruded so that the image data is easily acquired. By reasonable design, even if individual target surfaces are shielded, the target elements <NUM> on the remaining visible target surfaces may still be acquired and calculated. The target elements <NUM> of the multiple target surfaces are acquired and calculated, and thus, the positioning precision is improved.

In addition, two of the target surfaces are used as a group, so that the at least three target surfaces can be configured into multiple groups. Numerical values calculated according to the different groups of target surfaces are compared and calculated, if wheel position information calculated according to each group of target surfaces is consistent or smaller than a preset error range, factory settings are met, and measurement inaccuracy caused by structural variation, such as aging deformation or collision deformation, of the three-dimensional target <NUM> does not occur. Based on this, if the numerical values calculated according to all the groups of target surfaces are inconsistent or differ greatly, the factory settings are not met, and the three-dimensional target <NUM> needs to be replaced or returned to a factory so as to be calibrated.

Specifically, in the present embodiment, the base body <NUM> is shaped like a step, the base body <NUM> includes a first step <NUM>, a second step <NUM>, and a third step <NUM> which are integrally connected in sequence, an end surface of the first step <NUM> is provided with a first target surface <NUM>, an end surface of the second step <NUM> is provided with a second target surface <NUM>, and an end surface of the third step <NUM> is provided with a third target surface <NUM>, wherein the first target surface <NUM>, the second target surface <NUM> and the third target surface <NUM> are disposed in parallel, and the first target surface <NUM>, the second target surface <NUM> and the third target surface <NUM> face the same horizontal direction.

Further, the base body <NUM> is concavely provided with a mounting cavity <NUM>, and a fixing hole <NUM> which is through is disposed in the bottom of the mounting cavity <NUM>. By the fixing hole <NUM>, the base body <NUM> may be fixed to a calibrated object (such as a wheel <NUM> of a calibrated vehicle). Optionally, the mounting cavity <NUM> is concavely disposed towards the inside of the base body <NUM> from the side of the base body <NUM>, wherein an extension direction of the mounting cavity <NUM> is perpendicular to a direction that the first target surface <NUM> faces.

In the present embodiment, the base body <NUM> is concavely provided with the mounting cavity <NUM>, so that the three-dimensional target <NUM> is flexibly and conveniently mounted on the calibrated object, and meanwhile, the phenomenon that the target surfaces located on the base body <NUM> are shielded by the calibrated object or a fixing piece can be avoided as much as possible.

As shown in <FIG>, in some other embodiments, the first target surface <NUM> and the second target surface <NUM> are disposed to be unparallel.

A wheel positioning system is provided based on the three-dimensional target <NUM> as shown in <FIG> with reference to an application scenario as shown in <FIG>, and the wheel positioning system includes the three-dimensional target <NUM>, the image acquisition device <NUM> and the processing system <NUM>.

The three-dimensional target <NUM> is attached to a wheel <NUM>, the vision range of the image acquisition device <NUM> faces the three-dimensional target <NUM>, and the image acquisition device <NUM> is electrically connected to the processing system <NUM>.

The at least three target surfaces face the image acquisition device <NUM>, and the image acquisition device <NUM> is configured to acquire an image of each of the target surfaces in the at least three target surfaces.

The processing system <NUM> is configured to screen images of at least two of the target surfaces and determine the position of the wheel <NUM> according to the images of the at least two of the target surfaces.

In some other embodiments, two of the target surfaces are a group of calculation units, and the processing system <NUM> is further configured to calculate at least two pieces of wheel positioning information according to the images of the target elements <NUM> of at least two groups of calculation units, compare whether the at least two pieces of wheel positioning information are consistent, and determine the position of the wheel <NUM> according to the wheel positioning information if the at least two pieces of wheel positioning information are consistent.

For example, as shown in <FIG>, the image acquisition device <NUM> acquires the image of the three-dimensional target <NUM> and feeds the image back to the processing system <NUM>, and the processing system <NUM> recognizes and screens the first target surface <NUM>, the second target surface <NUM> and the third target surface <NUM>. The first target surface <NUM> and the second target surface <NUM> are used as a first group, the first target surface <NUM> and the third target surface <NUM> are used as a second group, if wheel positioning information calculated according to the target surfaces in the first group and wheel positioning information calculated according to the target surfaces in the second group are consistent or smaller than a preset error range, it is proven that the three-dimensional target <NUM> conforms to the factory settings, and the phenomenon of measure inaccuracy caused by structural variation does not occur in the three-dimensional target <NUM>.

As shown in <FIG>, if some target surfaces are shielded, for example, the third target surface <NUM> is partially shielded, the target elements <NUM> located on the third target surface <NUM> may not be recognized by the processing system <NUM>, and therefore, the processing system <NUM> may only recognize and acquire image data of the first target surface <NUM> and the second target surface <NUM>. When the three-dimensional target <NUM> is fixed to the calibrated object, the situation that some of the target surfaces are shielded may occur, but some of the target surfaces may also be protruded so that the image data is easily acquired. By reasonable design, even if individual target surfaces are shielded, the target elements <NUM> on the remaining visible target surfaces may still be acquired and calculated. The target elements <NUM> of the multiple target surfaces are acquired and calculated, and thus, the positioning precision is improved.

A wheel positioning method is provided based on the above-mentioned wheel positioning system. Specifically, the three-dimensional target <NUM> is attached to the outer surface of the wheel <NUM>. The image acquisition device <NUM> acquires images of the target elements <NUM> of two of the target surfaces in the at least three target surfaces, and the processing system <NUM> is configured to screen images of at least two of the target surfaces and determine the position of the wheel <NUM> according to the images of the at least two of the target surfaces.

For example, the processing system <NUM> recognizes and screens the images of the target elements <NUM> of two of the target surfaces from the images fed back by the image acquisition device <NUM>, and then, the position of the wheel <NUM> may be determined according to the images of the target elements <NUM> of the target surfaces. Further, before the position of the wheel <NUM> is determined, two of the target surfaces are a group of calculation units, numerical values calculated according to the different groups of target surfaces are compared and calculated, if wheel position information calculated according to each group of target surfaces is consistent or smaller than a preset error range, factory settings are met, and the position of the wheel <NUM> may be determined based on the images of the target elements <NUM> of the target surfaces. Optionally, the position of the wheel <NUM> is determined according to an average value of the wheel positioning information calculated by the multiple groups of calculation units.

As shown in <FIG>, the three-dimensional target <NUM> includes a base body <NUM>. The base body <NUM> is shaped like a stereoscopic block provided with multiple outer surfaces, and optionally, the base body <NUM> is of a regular geometrical shape. The base body <NUM> is provided with at least three target surfaces, and the at least three target surfaces are all in different planes, wherein the outer surfaces of the base body <NUM> are provided with at least three target surfaces, and the at least three target surfaces are all in different planes. The at least three target surfaces are each provided with target elements <NUM>, the spatial positional relationship between the target elements <NUM> is known, and the geometric properties of the target elements <NUM> are known, for example, the target surfaces are disposed at a preset angle, and the target surfaces are provided with the target elements <NUM> configured to be subjected to image acquisition, wherein the target elements <NUM> are geometric patterns which are concavely or convexly disposed. In the present embodiment, the target elements <NUM> are round spots concavely disposed in the target surfaces.

Specifically, in the present embodiment, the cross section of the base body <NUM> is trapezoidal, an end surface of the base body <NUM> is provided with a first target surface <NUM>, the other end surface of the base body <NUM> is provided with a second target surface <NUM>, the base body <NUM> extends outwards to form a convex part <NUM>, and the convex part <NUM> is provided with a third target surface <NUM>, wherein the first target surface <NUM> and the third target surface <NUM> are disposed in parallel, and the first target surface <NUM> and the third target surface <NUM> face the same horizontal direction. The second target surface <NUM> is located between the first target <NUM> and the third target surface <NUM>, and the first target surface and the second target surface <NUM> are disposed at a preset angle.

Further, the base body <NUM> is concavely provided with a mounting cavity <NUM>, and a fixing hole <NUM> which is through is disposed in the bottom of the mounting cavity <NUM>. By the fixing hole <NUM>, the base body <NUM> may be fixed to a calibrated object (such as a wheel <NUM> of a calibrated vehicle). Optionally, the mounting cavity <NUM> is concavely disposed towards the inside of the base body <NUM> from the side of the base body <NUM>, wherein the target elements <NUM> located on the second target surface <NUM> are disposed around the mounting cavity <NUM>.

Specifically, in the present embodiment, the base body <NUM> includes a first wall body <NUM>, a second wall body <NUM>, and a third wall body <NUM>. Every two of the first wall body <NUM>, the second wall body <NUM> and the third wall body <NUM> are perpendicular to each other to co-define a conical space <NUM>. The side, facing the conical space <NUM>, of the first wall body <NUM> is provided with a first target surface <NUM>, the side, facing the conical space <NUM>, of the second wall body <NUM> is provided with a second target surface <NUM>, and the side, facing the conical space <NUM>, of the second wall body <NUM> is provided with a third target surface <NUM>. Every two of the first target surface <NUM>, the second target surface <NUM> and the third target surface <NUM> are perpendicular to each other.

In summary, in the three-dimensional target <NUM> in the embodiments of the present application, the base body <NUM> is provided with at least three target surfaces, the at least three target surfaces are all in different planes, and the target surfaces are provided with the target elements <NUM> for calibration. Therefore, by using two target surfaces as a group, the at least three target surfaces can be configured into multiple groups, and calibration is performed according to the multiple groups of target surfaces, thus, the accuracy of calibration calculation can be improved. In addition, by comparing calibration parameters obtained by each group of target surfaces, it may be determined whether the three-dimensional target <NUM> meets a demand on precise calibration, and thus, the invalid three-dimensional target <NUM> may be replaced in time.

Claim 1:
A wheel positioning system, comprising a three-dimensional target (<NUM>), an image acquisition device (<NUM>), and a processing system (<NUM>), characterized in that:
the three-dimensional target (<NUM>) is attached to a wheel (<NUM>), the vision range of the image acquisition device (<NUM>) faces the three-dimensional target (<NUM>), and the image acquisition device (<NUM>) is electrically connected to the processing system (<NUM>);
wherein the three-dimensional target (<NUM>) comprises a base body (<NUM>); the base body (<NUM>) is provided with at least three target surfaces, and the at least three target surfaces are all in different planes; the at least three target surfaces are each provided with target elements (<NUM>), the spatial positional relationship between the target elements (<NUM>) is known, and the geometric properties of the target elements (<NUM>) are known; the at least three target surfaces face the image acquisition device (<NUM>);
the image acquisition device (<NUM>) is configured to acquire images of the target elements (<NUM>) of two of the target surfaces in the at least three target surfaces, wherein two of the target surfaces are a group of calculation units; and
the processing system (<NUM>) is configured to calculate at least two pieces of wheel positioning information according to the images of the target elements (<NUM>) of at least two groups of calculation units, compare whether the at least two pieces of wheel positioning information are consistent, and determine the position of the wheel (<NUM>) according to the wheel positioning information if the at least two pieces of wheel positioning information are consistent.