US-20260126465-A1 - VEHICLE WHEEL SPEED MEASURING DEVICE AND METHOD, AND ROLL AND BRAKE INSPECTION SYSTEM USING THE SAME

Abstract

A vehicle wheel speed measuring device may be incorporated into a roll and brake inspection system. The vehicle wheel speed measuring device includes a vision sensor that captures wheel images of driving wheels of a vehicle from a side of the vehicle to be inspected, and a control unit for calculating a wheel speed over time by analyzing real-time wheel images collected from the vision sensor based on one or more wheel characteristics, such as recognized time-series spoke shapes, profile lines, or spoke spacing.

Inventors

• Young Wook LEE
• Jaemin Lee

Assignees

• HYUNDAI MOTOR COMPANY
• KIA CORPORATION

Dates

Publication Date

20260507

Application Date

20250924

Priority Date

20240930

Claims (20)

1. 1 . A vehicle wheel speed measuring device comprising: a vision sensor that captures wheel images of driving wheels of a vehicle from a side of the vehicle to be inspected; and a control unit configured to calculate a wheel speed over time by analyzing the wheel images collected from the vision sensor based on one or more wheel characteristics.
2. 2 . The vehicle wheel speed measuring device of claim 1 , wherein: the controller extracts a spoke shape image recognized from the wheel image to generate a wheel speed measuring image, sets a profile line according to the same singular point as the adjacent spoke shapes in the generated image, and then measures the spoke spacing in real time based on the profile line to calculate a wheel speed over a time.
3. 3 . The vehicle wheel speed measuring device of claim 2 , wherein: the controller calculates the wheel speed by dividing the spoke spacing by a spoke detection time.
4. 4 . The vehicle wheel speed measuring device of claim 3 , wherein: the controller calculates the spoke spacing by dividing the tire circumference by the number of spokes.
5. 5 . The vehicle wheel speed measuring device of claim 3 , wherein: the controller calculates the spoke detection time (T) by multiplying the number of pixels per a predetermined time of the spoke spacing.
6. 6 . The vehicle wheel speed measuring device of claim 2 , wherein: the controller performs an image processing algorithm for removing image recognition impediments of the spoke shape image immediately before generating the wheel speed measuring image.
7. 7 . The vehicle wheel speed measuring device of claim 6 , wherein the image processing algorithm includes: a cluster processing of identifying the outline of a spoke shape forming a cluster pixel in the spoke shape image and processing the illumination values of pixels included within the outline similarly; a noise removal step for checking the minimum distance between pixels and determining a pixel clustering in the spoke shape image to determine and delete the illuminance values that are different from the actual spoke shape as a noise; and an illuminance equalization step of detecting illuminance values in real time from the spoke shape image and processing illuminance value deviations within a valid shape into equalized values.
8. 8 . The vehicle wheel speed measuring device of claim 1 , wherein the wheel images are obtained in real time.
9. 9 . The vehicle wheel speed measuring device of claim 1 , wherein the wheel images are analyzed by considering recognized time-series spoke shapes, profile lines, or spoke spacing.
10. 10 . A vehicle comprising the vehicle wheel speed measuring device of claim 1 .
11. 11 . A roll and brake inspection system comprising: a roll and brake (R/B) inspection device equipped with a driving roller and a retaining roller corresponding to at least one of front wheel or rear wheel positions of a vehicle; a wheel speed measuring device configured to capture a wheel image of the vehicle by using a vision sensor during a R/B inspection; and a controller configured to analyze the wheel image collected from the vision sensor to calculate a wheel speed based on one or more wheel characteristics, and controlling the R/B inspection device based on the wheel speed to perform the R/B inspection of the vehicle.
12. 12 . The roll and brake inspection system using the vision sensor of claim 11 , wherein: the controller includes: an external interface unit that is connected to a scanner, an antenna, and the vision sensor installed on a site to collect various information required for the R/B inspection; a motor driver selectively driving the motor of the drive roller according to the feedbacked wheel speed; a programmable logic controller (PLC) checking whether the driving roller is abnormal; a display unit for displaying an information collected or generated during the R/B inspection of the vehicle on a screen; and a control unit collecting a vehicle type and a sequence information, a vehicle status information, and a wheel image of the vehicle through the external interface unit, and controlling the R/B inspection based on the collected information.
13. 13 . The roll and brake inspection system using the vision sensor of claim 12 , wherein: the wheel speed measuring device includes a supporter for fixing the vision sensor to the side of the wheel of the vehicle; and a moving module installed at the lower part of the supporter, and sliding and moving along the guide rail to the front or rear wheel position.
14. 14 . The roll and brake inspection system using the vision sensor of claim 13 , wherein: the control unit identifies the driving wheel of the vehicle based on the vehicle type and sequence information, and moves the vision sensor installed so as to be able to slide through the guide rail and the moving module to the position of the driving wheel.
15. 15 . The roll and brake inspection system using the vision sensor of claim 12 , wherein: the controller generates a wheel speed measurement image by using a spoke shape image recognized from the wheel image, sets the profile line to the adjacent spoke shapes, and then measures the spoke spacing in real time based on the profile line to calculate the wheel speed according to the spoke detection time.
16. 16 . The roll and brake inspection system using the vision sensor of claim 15 , wherein: the controller feeds back the wheel speed to the motor drive unit to drive each motor of the drive roller corresponding to a non-driven wheel of the vehicle at the same speed as the wheel speed.
17. 17 . The roll and brake inspection system of claim 11 , wherein the wheel image is obtained in real time.
18. 18 . The roll and brake inspection system of claim 11 , wherein the wheel image is analyzed by considering recognized time-series spoke shapes, profile lines, or spoke spacing.
19. 19 . A vehicle wheel speed measuring method comprising: capturing, by a vision sensor, wheel images of driving wheels of a vehicle from a side of the vehicle to be inspected; and calculating, by a control unit, a wheel speed over time by analyzing the wheel images collected from the vision sensor based on one or more wheel characteristics.
20. 20 . The vehicle wheel speed measuring method of claim 19 , wherein the wheel images are obtained in real time.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims under 35 U.S.C. § 119(a) the benefit of Korean Patent Application No. 10-2024-0132603 filed with the Korean Intellectual Property Office on Sep. 30, 2024, the entire contents of which are incorporated herein by reference. BACKGROUND (a) Technical Field The present disclosure relates to a vehicle wheel speed measuring device and method and a roll and brake inspection system using the same, more particularly, to the vehicle wheel speed measuring device that incorporates an external vision sensor and the roll and brake inspection system using the same. (b) Description of the Related Art Typically, finished vehicles assembled at automobile factories undergo a roll and brake (R/B) inspection process, and if they are determined to pass inspection, they are shipped out. If any such finished vehicles are found to be defective (NG), the vehicles may undergo a repair process. FIG. 9 (PRIOR ART) is a view schematically illustrating a configuration of a roll and brake (R/B) inspection device of the prior art. Referring to FIG. 9, a R/B inspection device 1 of the prior art adjusts a wheel base to suit a vehicle type to be inspected, and when a tire 4 of the vehicle is positioned on a driving roller 2, a retaining roller 3 is raised and then the driving roller 2 is operated to perform a R/B inspection. At this time, an inspector may board the vehicle and sequentially conduct a high-speed driving test based on acceleration, a traction test and an electronic stability control (ESC) test based on a neutral (N) gear, a braking test based on a brake operation, and an anti-lock braking system (ABS) test. This conventional R/B inspection device 1 performs the R/B inspection using the roller speed measured using an encoder 5 installed at the shaft end of the driving roller 2. For example, a braking force test formula used in the R/B inspection is F=ma. Here, F represents a force, and refers to values such as a vehicle pulling force and a braking force in the R/B inspection device 1. The m is a mass constant value, for example, it has an equivalent weight of about 500 kg per each roll and is guaranteed through a mass constant value called a roller factor that is set internally in an equipment. The a refers to an acceleration/deceleration, which is derived by counting pulses output through the encoder 5 in a control panel to derive a speed value and calculating the acceleration/deceleration in real time. However, the conventional R/B inspection method using the encoder 5 has a disadvantage in that a slippage may occur between the tire 4 and the driving roller 2 due to the dispersion in the spacing of the retaining roll 3 or the sudden braking by the inspector, which may cause a defect in the performance. For example, when the inspector fails to maintain the appropriate brake pressure during the R/B inspection and applies the brakes suddenly, a momentary gap occurs between the tire 4 of the vehicle and the drive roller 2 driven by the friction, causing the slippage. Such slippage causes false failures in the items of the traction inspection, the ESC inspection, the braking inspection, and the ABS inspection during the R/B inspection. These cause problems such as a low pass rate during the R/B inspection and increased unnecessary inspection process man-hours (M/H). The above information disclosed in this Background section is only for enhancement of understanding of the background of the disclosure and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art. SUMMARY An embodiment of the present disclosure provides a vehicle wheel speed measuring device and a roll and brake inspection system using the same, which may fundamentally prevent a problem of false defects caused by the slippage between the vehicle and the drive roller during the conventional encoder speed-based roll and brake (R/B) inspection by directly measuring the wheel speed of the vehicle through a vision sensor disposed on the side of the roll and brake (R/B) inspection device and supporting performing the R/B inspection based on the measured wheel speed. According to the present disclosure, a vehicle wheel speed measuring device includes: a vision sensor that captures wheel images of driving wheels of a vehicle from a side of the vehicle to be inspected; and a control unit configured to calculate a wheel speed over time by analyzing the wheel images collected from the vision sensor based on one or more wheel characteristics. Exemplary wheel characteristics may include, for example, wheel spoke shapes, wheel profile lines, and/or wheel spoke spacing, or other wheel features. A vehicle may include the vehicle wheel speed measuring device. According to one aspect of the present disclosure, a vehicle wheel speed measuring device includes a vision sensor that captures wheel images of driving wheels from a side of a ve