CN104132818A - Three-dimensional four-wheel locator and measuring method thereof - Google Patents

Abstract

The invention relates to a three-dimensional four-wheel aligner and a measuring method thereof. The three-dimensional four-wheel aligner includes a top beam, a camera, a track platform, a fixed frame, a reflective target, a display device and a host, and the fixed frame fixes the reflective target on a plurality of tires; the reflective target There are two interlaced square patterns of two different colors and a sinusoidal pattern located at the center of the reflective target on the target, and the two square patterns are separated by the sinusoidal pattern; the camera is used to collect the reflective pattern target to obtain a target image comprising the square pattern and a sinusoidal block pattern; the host computer is used to process the target image to obtain the positioning parameters of the tire, and obtain the corresponding three-dimensional posture of the tire according to the positioning parameters; The display device displays the three-dimensional attitude of the tire. The above-mentioned three-dimensional four-wheel aligner and its measurement method contain many target feature points, and the positioning parameters obtained according to the image are more accurate, which improves the accuracy of measurement.

Description

Three-dimensional four-wheel aligner and its measuring method

technical field

The invention relates to a positioning detection device, in particular to a three-dimensional four-wheel alignment instrument and a measuring method thereof.

Background technique

According to the theory of automobile technology, the installation of tires on the body must meet certain angle requirements, among which the most important angles are toe angle, camber angle, kingpin inclination angle, kingpin caster angle and so on. After the vehicle has been running for a period of time, these parameters may change, which will affect the performance of the vehicle, and the vehicle needs to be re-measured and adjusted.

The traditional measurement method is to install the reflective target on the car tire, and point the industrial camera at the reflective target to take pictures, and then process the captured image to calculate the positioning parameters of the car tire. The positioning parameters include toe angle, Camber, kingpin inclination, kingpin caster, etc. Because the traditional reflective markers have fewer target points, there are fewer target points in the captured reflective target image, and the fitted target motion cycloid is inaccurate, resulting in inaccurate tire positioning parameters.

Contents of the invention

Based on this, it is necessary to provide a three-dimensional four-wheel aligner and a measurement method thereof that can improve measurement accuracy for the problem of inaccurate positioning parameters measured by traditional measurement methods.

A three-dimensional four-wheel aligner, comprising a top beam, a camera and a rail platform suspended on the top beam, the three-dimensional four-wheel aligner also includes a fixed frame, a reflective target, a display device and a host, the camera is installed On the track platform, the fixed frame fixedly installs the reflective target on a plurality of tires, and the reflective target is located within the shooting angle of view of the camera; The equipment is connected; the reflective target is provided with two interlaced square patterns of two different colors and a sinusoidal block pattern located in the center of the reflective target, and the two square patterns are separated by the sinusoidal block pattern; the camera It is used to collect the reflective target, obtain the target image including the square pattern and the sinusoidal block pattern, and send the target image to the host; the host is used to process the target image , obtain the positioning parameters of the tire, obtain the corresponding three-dimensional posture of the tire according to the positioning parameters, and send the three-dimensional posture of the tire to the display device; the display device is also used to display the three-dimensional posture of the tire.

In one of the embodiments, the host is also used to pre-establish the corresponding relationship between the coordinates of the feature points of the plane target in the space coordinate system and the image coordinates of the corresponding pixels in the image, and calculate the relative For the three-dimensional attitude of the camera, the continuous three-dimensional attitude change of the reflective target relative to the camera is obtained by calculating a set of target images, and the motion cycloid of the reflective target is obtained by fitting the continuous three-dimensional attitude change of the reflective target relative to the camera, The rotation center vector of the tire is calculated according to the motion cycloid, the rotation center vector is projected onto the motion plane of the vehicle, and the positioning parameter of the tire is obtained according to the angle between the rotation center vectors.

In one embodiment, the calculation by the host computer of the three-dimensional pose of the reflective target relative to the camera according to the corresponding relationship includes: processing the target image to obtain corner points and sinusoidal block edges of blocks of two different colors Curve, with the target plane as the XY plane, perpendicular to the XY plane as the Z plane, establish a three-dimensional coordinate system, calculate the three-dimensional coordinates of the corner points and the three-dimensional coordinates of the sine block edge curve according to the size of the reflective target and the pattern size , and calculate the coordinates of the corner points in the target image and the coordinates of the sine block edge curve in the target image, according to the three-dimensional coordinates of the corner points and the coordinates of the corner points in the target image Coordinates, establish the equation equation of the three-dimensional attitude of the reflective target relative to the camera, according to the three-dimensional coordinates of the sinusoidal block edge curve and the coordinates of the sinusoidal block edge curve in the target image, the target image in the target image Perform Fourier transform on the sine block edge curve, set up the equation equation of the three-dimensional attitude of the reflective target relative to the camera according to the Fourier transform coefficients, and solve the two equations to obtain the three-dimensional attitude parameters of the two groups of reflective targets relative to the camera The three-dimensional attitude parameters of the two groups of reflective targets relative to the camera are fused to obtain the final three-dimensional attitude parameters of the reflective target relative to the camera.

In one of the embodiments, the camera is installed vertically on the track platform, and the shooting angle of the camera is facing the reflective target, and the camera can slide on the track platform; the track platform lifting relative to the top beam; the two different colors include black and white.

In one of the embodiments, the three-dimensional four-wheel aligner further includes supplementary light equipment installed on the track platform, and the supplementary light equipment is used for illuminating the reflective target.

In one of the embodiments, the camera is also used to collect reflective targets of multiple tires at the same time, to obtain target images containing the block pattern and sinusoidal block pattern of each tire, and to display the target images of each tire The image is sent to the host; the host is also used to process the target image of each tire to obtain the positioning parameters of each tire.

A method for measuring a three-dimensional four-wheel aligner, comprising the following steps:

A three-dimensional four-wheel aligner is provided, the three-dimensional four-wheel aligner includes a top beam, a camera and a track platform suspended on the top beam, a fixed frame, a reflective target, a display device and a host, and the camera is installed on the On the track platform, the host is connected to the camera and the display device respectively, and the reflective target is provided with two interlaced square patterns of two different colors and a sinusoidal block pattern located in the center of the reflective target, and the two block patterns are separated by the sinusoidal block patterns;

The vehicle is placed under the roof beam, and the roof beam is parallel to the longitudinal axis of the vehicle body, and the reflective target is fixedly installed on a plurality of tires of the vehicle through the fixing frame, and the The reflective target is located within the shooting angle of view of the camera;

Instructing to push the vehicle through the host computer, collecting target images including the square pattern and the sinusoidal block pattern through the camera, and sending the target image to the host computer;

Processing the target image by the host computer to obtain tire positioning parameters, obtaining the corresponding three-dimensional posture of the tire according to the positioning parameters, and sending the three-dimensional posture of the tire to the display device;

The three-dimensional posture of the tire is displayed through the display device.

In one of the embodiments, the host processes the target image, and the step of obtaining tire positioning parameters includes:

The corresponding relationship between the coordinates of the feature points of the plane target in the space coordinate system and the image coordinates of the corresponding pixel points in the image is established in advance, and the three-dimensional pose of the reflective target relative to the camera is calculated according to the corresponding relationship, and obtained by calculating a set of target images The continuous three-dimensional attitude change of the reflective target relative to the camera, fitting the continuous three-dimensional attitude change of the reflective target relative to the camera to obtain the motion cycloid of the reflective target, and calculating the rotation center vector of the tire according to the motion cycloid , projecting the rotation center vector to the motion plane of the vehicle, and calculating the positioning parameters of the tire according to the angle between the rotation center vectors.

In one of the embodiments, the step of calculating the three-dimensional pose of the reflective target relative to the camera according to the corresponding relationship includes:

The target image is processed to obtain the corner points and sine block edge curves of two different colors of squares, the target plane is the XY plane, and the plane perpendicular to the XY plane is the Z plane, and a three-dimensional coordinate system is established. According to the The size of the reflective target and the size of the pattern are calculated to obtain the three-dimensional coordinates of the corner points and the three-dimensional coordinates of the sinusoidal block edge curve, and calculate the coordinates of the corner points in the target image and the sinusoidal block edge curve in the target image Coordinates, according to the three-dimensional coordinates of the corner point and the coordinates of the corner point in the target image, establish the equation equation of the three-dimensional attitude of the reflective target relative to the camera, according to the three-dimensional coordinates of the sinusoidal block edge curve and the Coordinates of the sinusoidal block edge curve in the target image, performing Fourier transform on the sinusoidal block edge curve in the target image, and establishing the three-dimensional attitude of the reflective target relative to the camera according to the Fourier transform coefficients Equation equations, solving two equations to obtain the three-dimensional attitude parameters of the two groups of reflective targets relative to the camera, and fusing the three-dimensional attitude parameters of the two groups of reflective targets relative to the camera to obtain the final three-dimensional attitude parameters of the reflective target relative to the camera.

In one of the embodiments, the step of solving two equations to obtain two sets of three-dimensional attitude parameters of the reflective target relative to the camera includes using linear least squares or nonlinear least squares to solve two equations to obtain two sets of The 3D pose parameters of the reflective target relative to the camera.

In one of the embodiments, the two different colors include black and white;

The method also includes:

A supplementary light device is provided through which the reflective target is irradiated.

In one embodiment, the method also includes:

The camera is also used to collect reflective targets of multiple tires at the same time, obtain target images containing the square pattern and sinusoidal block pattern of each tire, and send the target images of each tire to the host ;

The host computer is also used to process the target image of each tire to obtain the positioning parameters of each tire.

The above-mentioned three-dimensional four-wheel aligner and its measurement method, by setting two different color interlaced square patterns and sinusoidal block patterns on the reflective target, collecting the reflective target through the camera to obtain the target image, and processing the target image to obtain the tire According to the positioning parameters, the three-dimensional posture of the tire is obtained according to the positioning parameters. Since the block pattern and the sinusoidal block pattern on the reflective target are used as the target feature points, the image collected by the camera contains many target feature points. According to the image, the The positioning parameters are more accurate, the measurement accuracy is improved, and the three-dimensional posture of the tire is displayed, which is convenient for the operator to maintain and adjust the vehicle. In addition, commercial vehicles or passenger vehicles can be measured by adjusting the height of the rail platform and the position of the camera.

Description of drawings

Fig. 1 is the structural representation of three-dimensional four-wheel aligner in an embodiment;

Figure 2 is a schematic diagram of a reflective target pattern;

Fig. 3 is a flowchart of a measuring method of a three-dimensional four-wheel aligner in an embodiment.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

Fig. 1 is a schematic structural diagram of a three-dimensional four-wheel aligner in an embodiment. As shown in FIG. 1 , the three-dimensional four-wheel aligner includes a top beam 110 , a rail platform 120 , a camera 130 , a fixed frame 140 , a reflective target 150 , a display device 160 and a host computer 170 .

The track platform 120 is suspended on the top beam 110 . In this embodiment, the track platform 120 can be raised and lowered relative to the top beam 110 , that is, the distance between the track platform 120 and the top beam 110 can be adjusted in the vertical direction. It should be noted that, during measurement, the vehicle is placed under the roof beam 110 , and the roof beam 110 is parallel to the longitudinal axis of the vehicle body.

The camera 130 is installed on the track platform 120 . In this embodiment, the camera 130 can slide on the track platform 120 to change its fixed position, which is convenient to adjust according to the distance between multiple sets of tires of the vehicle, and is suitable for shooting tire images of different types of vehicles. The camera 130 may use CCD (Charge Coupled Devices, photoelectric charge coupled devices). CCD is an image sensor. When the light irradiates the image sensitive unit on the CCD, signal charge is generated, and the signal charge is output, which is collected and processed by the microcomputer processor on the sensor. According to the image of the irradiated image sensitive unit, it can be accurately The three-dimensional pose of the object being photographed and the object is calculated.

In this embodiment, the camera 130 is installed vertically on the track platform 120 , and the shooting angle of the camera 130 faces the reflective target 150 . Since the camera 130 is installed vertically on the track platform 120, multiple tires can be measured at the same time, which improves the measurement efficiency, and the distance between the camera 130 and each tire is the same, and the measurement accuracy of each tire is the same.

The fixing frame 140 fixedly installs the reflective target 150 on a plurality of tires 180 , and the reflective target 150 is located within the viewing angle of the camera 130 .

The reflective target 150 is provided with two interlaced square patterns of two different colors and a sinusoidal block pattern located at the center of the reflective target, and the two square patterns are separated by the sinusoidal block pattern. The two different colors may include black and white, or black and green, or red and green, and so on. In this embodiment, the two different colors are black and white, and the sinusoidal block pattern is black. The size and dimensions of the reflective target pattern can be adjusted as needed. Preferably, the pattern aspect ratio of the reflective target 150 is 4:3, the length is 40 cm (centimeter), and the width is 30 cm. The side length of each black and white square is 2.5cm. The length and width of the sinusoidal block pattern are respectively 36cm and 27cm, but not limited thereto. Fig. 2 is a schematic diagram of a reflective target pattern. As shown in FIG. 2 , a black and white interlaced square pattern 152 and a sinusoidal square pattern 154 are provided on the reflective target 150 .

The host 170 is connected to the camera 130 and the display device 160 respectively.

The camera 130 is used to collect the reflective target 150, obtain the target image including the square pattern and the sinusoidal block pattern, and send the target image to the host 170; the host 170 is used to process the target image , obtain the positioning parameters of the tire, obtain the corresponding three-dimensional posture of the tire according to the positioning parameters, and send the three-dimensional posture of the tire to the display device 160; the display device 160 is also used to display the three-dimensional posture of the tire according to the positioning parameters.

Specifically, the positioning parameters include toe-in angle, camber angle, kingpin inclination angle, kingpin caster angle and the like.

The above-mentioned three-dimensional four-wheel aligner, by setting two different color interlaced block patterns and sinusoidal block patterns on the reflective target, collects the reflective target through the camera to obtain the target image, and processes the target image to obtain the positioning parameters of the tire. Then the three-dimensional attitude of the tire is obtained according to the positioning parameters. Because the block pattern and the sinusoidal block pattern on the reflective target are used as the target feature points, the image collected by the camera contains many target feature points, and the positioning parameters obtained according to the image are more accurate. , which improves the accuracy of the measurement, and displays the three-dimensional attitude of the tire, which is convenient for the operator to repair and adjust the vehicle.

Before all the embodiments, the camera needs to be calibrated, that is, the internal parameters in the perspective transformation equation and the internal parameters in the external parameters are determined. The calibration adopts the Bouguet calibration method. Under the three-dimensional coordinate system established on the basis of the target, the three-dimensional coordinates of each point in the target can be determined, and at the same time, after the camera shooting position is fixed, the position of each point on the target in the image can also be calculated get. According to these characteristics, according to the three-dimensional coordinates of each point on the target and the two-dimensional coordinates of the corresponding points in the image obtained by image processing means, the shooting position of the camera can be calculated, and the model established by the shooting position of the camera is the perspective transformation equation . The internal parameters of the perspective transformation equation are the focal length of the camera, the principal point, the skewness coefficient, the distortion, and the like. Among them, the principal point refers to the intersection of the camera optical axis and the image plane; the focal length is the distance between the optical center of the camera and the principal point; the skewness coefficient refers to the angle between the x and y pixel axes; distortion refers to some image distortion factor.

In one embodiment, the host computer 170 is also used to pre-establish the corresponding relationship between the coordinates of the feature points of the plane target in the space coordinate system and the image coordinates of the corresponding pixel points in the image, and calculate the position of the reflective target relative to the camera according to the corresponding relationship. Three-dimensional attitude, the continuous three-dimensional attitude change of the reflective target relative to the camera is obtained by calculating a set of target images, and the continuous three-dimensional attitude change of the reflective target relative to the camera is fitted to obtain the motion cycloid of the reflective target. According to the motion The rotation center vector of the tire is obtained through the cycloid calculation, and the rotation center vector is projected onto the motion plane of the vehicle, and the positioning parameters of the tire are obtained according to the angle between the rotation center vectors.

Further, the host computer 170 calculates the three-dimensional pose of the reflective target relative to the camera according to the corresponding relationship, including: processing the target image to obtain corner points and sinusoidal block edge curves of two different colors of blocks, using the Harris method or The Shi method or Tomasi method is used to obtain corner points, and the fixed threshold method is used to binarize to obtain the sine block edge curve. Take the target plane as the XY plane, and the Z plane perpendicular to the XY plane, establish a three-dimensional coordinate system, calculate the three-dimensional coordinates of the corner point and the three-dimensional coordinates of the edge curve of the sinusoidal block according to the size of the reflective target design, according to the corner point The three-dimensional coordinates and the coordinates of the corner points in the target image establish an equation equation of the three-dimensional attitude of the reflective cursor target relative to the camera, and this equation equation is a perspective transformation equation. According to the three-dimensional coordinates of the sinusoidal block edge curve, the coordinates of the sinusoidal block edge curve in the target image are obtained, the Fourier transform is performed on the sinusoidal block edge curve, and the three-dimensional reflection target relative to the camera is established according to the Fourier transform coefficients. Equation of the pose, this equation is determined by pre-fitting. Because for the sinusoidal curve, there is a functional relationship between the frequency of the sinusoidal curve and the shooting position of the camera, that is, the fitting function. The specific method is to pre-acquire a large number of Fourier transform coefficients of sinusoidal curves (ie, sinusoidal block edge curves) in the reflective target (under different determined three-dimensional attitudes), and fit these data to obtain a fitting function. The Fourier transform is performed on the sinusoidal block edge curve, and the equation equation of the three-dimensional attitude of the reflective target relative to the camera established according to the Fourier transform coefficient is the fitting function. Solve the two equations to obtain the three-dimensional attitude parameters of the two groups of reflective targets relative to the camera, and fuse the three-dimensional attitude parameters of the two groups of reflective targets relative to the camera to obtain the final three-dimensional attitude parameters of the reflective target relative to the camera.

Specifically, the corner points refer to the positions of the four corners of each unit block in the black and white interlaced square pattern, and the corner points of the black and white interlaced square pattern are obtained by using a corner point detection algorithm. For the corner point, the coordinates of the corner point in the target image can be obtained according to the pre-established correspondence between the coordinates of the feature points of the plane target in the space coordinate system and the image coordinates of the corresponding pixel points in the image, and the three-dimensional coordinates of the corner point . The three-dimensional coordinates of corner points or sinusoidal curves are calculated based on fixed target size and pattern size.

For the sinusoidal block edge curve, according to the corresponding relationship between the coordinates of the plane target feature points in the space coordinate system and the corresponding pixel image coordinates in the image, and the three-dimensional coordinates of the sinusoidal block edge curve, the sinusoidal block edge curve can be obtained at The coordinates in the target image can be angle-corrected first, even if the angle of the straight line edge of the sine block is 90 degrees, the Fourier transform is performed on the edge curve of the sine block, and the reflective target relative to the camera is established according to the Fourier transform coefficient Equations of Equations for 3D Pose.

The linear least square method or the nonlinear least square method can be used to solve the two equations to obtain the three-dimensional attitude parameters of the two groups of reflective targets relative to the camera. Then measure the black and white interlaced block pattern and the sinusoidal block pattern to obtain the accuracy of the result, according to the accuracy, two sets of three-dimensional attitude parameters are fused to obtain the final three-dimensional attitude parameters. Among them, the three-dimensional attitude measurement accuracy of the two patterns is obtained through pre-testing. The fusion method is weighted average, and the inverse ratio of measurement accuracy is used as the weighting coefficient to perform weighted average to obtain the final measurement result. The fusion method is not limited to weighted average, and D-S evidence theory method, Kalman filter, etc. can also be used.

The three-dimensional four-wheel aligner also includes supplementary light equipment, which is installed on the track platform 120. The supplementary light equipment illuminates the reflective target 150, which is convenient for the camera 130 to collect images, and is suitable for scenes with darker lighting environments. The supplementary light device may be a supplementary light.

Fig. 3 is a flowchart of a measuring method of a three-dimensional four-wheel aligner in an embodiment. The three-dimensional four-wheel aligner is the above-mentioned three-dimensional four-wheel aligner. As shown in Figure 3, the measuring method of this three-dimensional four-wheel aligner comprises the following steps:

Step 302, providing a three-dimensional four-wheel aligner, the three-dimensional four-wheel aligner includes a top beam, a track platform suspended on the top beam, a camera, a fixed frame, a reflective target, a display device and a host, and the camera is installed on the track On the platform, the host computer is respectively connected with the camera and the display device, and the reflective target is provided with two interlaced square patterns of two different colors and a sinusoidal block pattern located in the center of the reflective target, and the two square patterns are covered by the Sine block pattern separated.

Specifically, the two different colors include black and white.

Step 304, place the vehicle under the roof beam, and the roof beam is parallel to the longitudinal axis of the vehicle body, fix the reflective target on multiple tires of the vehicle through the fixing frame, and the reflective target within the field of view of the camera.

In step 306, the host computer instructs to push the vehicle, and the camera captures the target image including the square pattern and the sinusoidal block pattern, and sends the target image to the host computer.

In step 308, the target image is processed by the host computer to obtain tire positioning parameters, and the corresponding three-dimensional posture of the tire is obtained according to the positioning parameters, and the three-dimensional posture of the tire is sent to the display device.

In one embodiment, the host computer processes the target image to obtain the positioning parameters of the tire. The step includes: pre-establishing the corresponding relationship between the coordinates of the plane target feature points in the space coordinate system and the image coordinates of the corresponding pixel points in the image, Calculate the three-dimensional attitude of the reflective target relative to the camera according to the corresponding relationship, and obtain the continuous three-dimensional attitude change of the reflective target relative to the camera by calculating a set of target images, and simulate the continuous three-dimensional attitude change of the reflective target relative to the camera. Combined to get the motion cycloid of the reflective target, calculate the rotation center vector of the tire according to the motion cycloid, project the rotation center vector to the motion plane of the vehicle, and calculate the tire rotation angle according to the angle between the rotation center vectors positioning parameters.

Further, the step of calculating the three-dimensional attitude of the reflective target relative to the camera according to the corresponding relationship includes: processing the target image to obtain corner points and sinusoidal block edge curves of two different colors of blocks, taking the target plane as XY plane, perpendicular to the XY plane is the Z plane, establish a three-dimensional coordinate system, calculate the three-dimensional coordinates of the corner points and the three-dimensional coordinates of the sine block edge curve according to the size of the reflective target and the size of the pattern, and use the Harris method or Shi method or Tomasi method to calculate the coordinates of the corner point in the target image and use the fixed threshold method binarization to obtain the coordinates of the sinusoidal block edge curve in the target image, according to the three-dimensional coordinates of the corner point and the corner point in the target image The coordinates in the target image, establish the equation of the three-dimensional posture of the reflective target relative to the camera, according to the three-dimensional coordinates of the sinusoidal block edge curve and the coordinates of the sinusoidal block edge curve in the target image, the target image in the The sinusoidal block edge curve is subjected to Fourier transform, and according to the Fourier transform coefficient, the equation equation of the three-dimensional attitude of the reflective target relative to the camera is established, and the two equations are solved to obtain the three-dimensional attitude parameters of the two groups of reflective target relative to the camera, The three-dimensional attitude parameters of the two groups of reflective targets relative to the camera are fused to obtain the final three-dimensional attitude parameters of the reflective target relative to the camera.

The step of solving the two equations to obtain the three-dimensional attitude parameters of the two groups of reflective targets relative to the camera includes using a linear least square method or a nonlinear least square method to solve the two equations to obtain the three-dimensional attitude parameters of the two groups of reflective targets relative to the camera. parameter.

Step 310, displaying the three-dimensional posture of the tire through the display device.

The measurement method of the above-mentioned three-dimensional four-wheel aligner is to set two different color interlaced square patterns and sinusoidal block patterns on the reflective target, collect the reflective target through the camera to obtain the target image, and process the target image to obtain the tire Positioning parameters, and then obtain the three-dimensional posture of the tire according to the positioning parameters. Because the block pattern and the sinusoidal block pattern on the reflective target are used as the target feature points, the image collected by the camera contains many target feature points, and the positioning obtained according to the image The parameters are more accurate, the measurement accuracy is improved, and the three-dimensional posture of the tire is displayed, which is convenient for the operator to repair and adjust the vehicle. In addition, commercial vehicles or passenger vehicles can be measured by adjusting the height of the rail platform and the position of the camera.

Further, the measuring method of the three-dimensional four-wheel aligner further includes: providing supplementary light equipment, and providing light to the camera through the supplementary light equipment.

The above-mentioned embodiments only express several implementation modes of the present invention, and the description thereof is relatively specific and detailed, but should not be construed as limiting the patent scope of the present invention. It should be pointed out that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be based on the appended claims.

Claims (12)

1. a three-dimensional four-wheel position finder, comprise back timber, video camera and be suspended on the orbital platform on described back timber, it is characterized in that, described three-dimensional four-wheel position finder also comprises fixed mount, reflective target, display device and main frame, described video camera is arranged on described orbital platform, described fixed mount is fixedly mounted on described reflective target on a plurality of tires, and described reflecting sign target is positioned at the shooting visual angle of described video camera; Described main frame is connected with display device with described video camera respectively; Described reflective target is provided with two square patterns and the sine block pattern that is positioned at reflecting sign pinwheel that two kinds of different colours are staggered, and described two square patterns are separated by described sine block pattern; Described video camera is used for gathering described reflective target, obtains the target image that comprises described square pattern and sine block pattern, and described target image is sent to described main frame; Described main frame, for described target image is processed, obtains the positional parameter of tire, obtains the corresponding 3 d pose of tire, and the 3 d pose of described tire is sent to described display device according to described positional parameter; Described display device is for the 3 d pose of display of tyre.

2. three-dimensional four-wheel position finder according to claim 1, it is characterized in that, described main frame is also for setting up in advance the corresponding relation of plane target unique point coordinate and image corresponding pixel points image coordinate under space coordinates, according to described corresponding relation, calculate reflective target with respect to the 3 d pose of video camera, the continuous 3 d pose that obtains the relative video camera of reflective target by calculating one group of target image changes, described reflective target is carried out to the motion cycloid that matching obtains reflective target with respect to the continuous 3 d pose variation of video camera, according to described motion cycloid, calculate the rotation center vector of tire, plane of movement by described rotation center vector projection to vehicle, according to the angle between described rotation center vector, obtain the positional parameter of tire.

3. three-dimensional four-wheel position finder according to claim 2, it is characterized in that, described main frame calculates reflective target according to described corresponding relation and comprises with respect to the 3 d pose of video camera: angle point and the sine block boundary curve of described target image being processed to the square of asking for two kinds of different colours, take target plane as XY plane, perpendicular to described XY plane, it is Z plane, set up three-dimensional system of coordinate, according to described reflective target size and pattern dimension reckoning, obtain the three-dimensional coordinate of angle point and the three-dimensional coordinate of sine block boundary curve, and calculate coordinate and the described sine block boundary curve coordinate in described target image of angle point in described target image, the coordinate in described target image according to the three-dimensional coordinate of described angle point and angle point, set up the equation equation of the relative video camera 3 d pose of reflective target, the coordinate in described target image according to the three-dimensional coordinate of described sine block boundary curve and described sine block boundary curve, described sine block boundary curve in described target image is carried out to Fourier transform, according to described Fourier Transform Coefficients, set up the equation equation of the relative video camera 3 d pose of reflective target, solve the 3 d pose parameter that two equation equations obtain two groups of relative video cameras of reflective target, the 3 d pose parameter that merges two groups of relative video cameras of reflective target obtains the 3 d pose parameter of the final relative video camera of reflective target.

4. three-dimensional four-wheel position finder according to claim 1, is characterized in that, described video camera is vertically mounted on described orbital platform, and the shooting visual angle of described video camera is facing to described reflective target, and described video camera can slide on described orbital platform; Described orbital platform carries out lifting with respect to described back timber; Described two kinds of different colours comprise black and white.

5. three-dimensional four-wheel position finder according to claim 1, is characterized in that, described three-dimensional four-wheel position finder also comprises the light filling equipment being arranged on described orbital platform, and described light filling equipment is used for irradiating described reflective target.

6. three-dimensional four-wheel position finder according to claim 1, it is characterized in that, described video camera is also for gather the reflective target of a plurality of tires simultaneously, obtain comprising of each tire of described square pattern and the target image of sine block pattern, and the target image of described each tire is sent to described main frame; Described main frame is also processed for the described target image to each tire, obtains the positional parameter of each tire.

7. a measuring method for three-dimensional four-wheel position finder, comprises the following steps:

Three-dimensional four-wheel position finder is provided, described three-dimensional four-wheel position finder comprises back timber, video camera and is suspended on orbital platform, fixed mount, reflective target, display device and the main frame on described back timber, described video camera is arranged on described orbital platform, described main frame is connected with display device with described video camera respectively, described reflective target is provided with two square patterns and the sine block pattern that is positioned at reflecting sign pinwheel that two kinds of different colours are staggered, and described two square patterns are separated by described sine block pattern;

Vehicle is placed in to described back timber below, and described back timber is parallel with described carbody longitudinal axis, by described fixed mount, described reflective target is fixedly mounted on a plurality of tires of described vehicle, and described reflecting sign target is positioned at the shooting visual angle of described video camera;

By described main frame indication, promote vehicle, by described camera acquisition, comprise the target image of stating square pattern and sine block pattern, and described target image is sent to described main frame;

By described main frame, described target image is processed, obtained the positional parameter of tire, according to described positional parameter, obtain the corresponding 3 d pose of tire, and the 3 d pose of described tire is sent to described display device;

By the 3 d pose of described display device display of tyre.

8. the measuring method of three-dimensional four-wheel position finder according to claim 7, is characterized in that, described main frame is processed described target image, and the step that obtains the positional parameter of tire comprises:

Set up in advance plane target unique point corresponding relation of corresponding pixel points image coordinate in coordinate and image under space coordinates, according to described corresponding relation, calculate reflective target with respect to the 3 d pose of video camera, the continuous 3 d pose that obtains the relative video camera of reflective target by calculating one group of target image changes, described reflective target is carried out to the motion cycloid that matching obtains reflective target with respect to the continuous 3 d pose variation of video camera, according to described motion cycloid, calculate the rotation center vector of tire, plane of movement by described rotation center vector projection to vehicle, according to the angle between described rotation center vector, obtain the positional parameter of tire.

9. the measuring method of three-dimensional four-wheel position finder according to claim 8, is characterized in that, calculates reflective target comprise with respect to the step of the 3 d pose of video camera according to described corresponding relation:

Described target image is processed to angle point and the sine block boundary curve of the square of asking for two kinds of different colours, take target plane as XY plane, perpendicular to described XY plane, it is Z plane, set up three-dimensional system of coordinate, according to described reflective target size and pattern dimension reckoning, obtain the three-dimensional coordinate of angle point and the three-dimensional coordinate of sine block boundary curve, and calculate coordinate and the sine block boundary curve coordinate in described target image of angle point in described target image, the coordinate in described target image according to the three-dimensional coordinate of described angle point and angle point, set up the equation equation of the relative video camera 3 d pose of reflective target, the coordinate in described target image according to the three-dimensional coordinate of described sine block boundary curve and described sine block boundary curve, wherein, sine block boundary curve described in described target image is carried out to Fourier transform, according to described Fourier Transform Coefficients, set up the equation equation of the relative video camera 3 d pose of reflective target, solve the 3 d pose parameter that two equation equations obtain two groups of relative video cameras of reflective target, the 3 d pose parameter that merges two groups of relative video cameras of reflective target obtains the 3 d pose parameter of the final relative video camera of reflective target.

10. the measuring method of three-dimensional four-wheel position finder according to claim 9, it is characterized in that, described in solve step that two equation equations obtain the 3 d pose parameter of two groups of relative video cameras of reflective target and comprise and adopt linear least square or nonlinear least square method to solve the 3 d pose parameter that two equation equations obtain two groups of relative video cameras of reflective target.

The measuring method of 11. three-dimensional four-wheel position finders according to claim 7, is characterized in that, described two kinds of different colours comprise black and white;

Described method also comprises:

Light filling equipment is provided, by described light filling equipment, irradiates described reflective target.

The measuring method of 12. three-dimensional four-wheel position finders according to claim 7, is characterized in that, described method also comprises:

By described video camera, also for gather the reflective target of a plurality of tires simultaneously, obtain comprising of each tire of described square pattern and the target image of sine block pattern, and the target image of described each tire is sent to described main frame;

By described main frame, also for the described target image to each tire, process, obtain the positional parameter of each tire.