Brake pad dimension estimation system

A brake pad dimension estimation system includes a detecting device and an electronic controller. The detecting device is configured to obtain dimensional information from an image of a brake pad assembly. The electronic controller is in electronic communication with the detecting device to receive the dimensional information from the image of the brake pad assembly. The electronic controller is programmed to determine a dimension of the brake pad based on the image.

BACKGROUND

Technical Field

The present disclosure generally relates to a brake pad dimension estimation system. More specifically, the present disclosure relates to a brake pad dimension estimation system using optical information of a brake pad.

Background Information

Traditionally, measuring a brake pad thickness requires a series of complicated steps, including removing the tire, identifying the caliper and removing the bolts on the caliper. The caliper door can then be opened in order to access the brake pads. The brake pads are then removed for measuring. The complicated technique increases the cost of service for brake pad replacement at the dealership, particularly if the brake pads and are removed and measurement finds that no replacement is necessary. In these circumstances, the dealership absorbs the lost labor cost of disassembling the brake caliper assembly.

SUMMARY

In view of the state of the known technology, one aspect of the present disclosure is to provide a brake pad dimension estimation system includes a detecting device and an electronic controller. The detecting device is configured to obtain dimensional information from an image of a brake pad assembly. The electronic controller is in electronic communication with the detecting device to receive the dimensional information from the image of the brake pad assembly. The electronic controller is programmed to determine a dimension of the brake pad based on the image.

In view of the state of the known technology, another aspect of the present disclosure is to provide a method for estimating a brake pad dimension. The method comprising arranging a detecting device with respect to a vehicle brake caliper so that the detecting device captures an image of a brake pad assembly along a direction that is substantially tangent to a curve of the brake pad assembly. The method further comprises capturing the image of the brake pad assembly along the direction that is substantially tangent to the curve of the brake pad assembly. The method further comprises using a mobile device to determine a thickness of the brake pad assembly based on the captured image of the brake pad assembly.

DETAILED DESCRIPTION OF EMBODIMENTS

Referring initially toFIG.1, a vehicle brake caliper assembly10for a vehicle12is illustrated in accordance with an embodiment. The brake caliper assembly10includes a brake rotor1414arranged along an axle16. The vehicle brake caliper24further includes a vehicle tire18that is mounted to the axle16that receives rotational force from the axle16. As best seen inFIG.3, the brake caliper further includes a pair of first (outside) and second (inside) brake pads20and22, and a brake caliper24. The brake caliper24operates the brake pads20and22to grip the brake rotor14. The brake pads20and22contact the brake rotor14to provide friction to the rotor14which enables the tire18to slow down and stop the vehicle10.

The brake pads20and22are made of frictional material such as metallic fibers or metallic alloy fibers that are bonded to a backing plate26(i.e., a metal plate). The brake pads20and22are fixed to respective backing plates26and28in a conventional manner such as using rivets, adhesive, mold-in techniques or a mechanical retention system as appropriate. The backing plate26is typically made from steel and transfers force from the brake caliper piston evenly across the backing plate26to apply the friction material to the brake rotor14.

In the illustrated embodiment, as the first and second brake pads20and22are identical, only the first brake pad20(outside brake pad20) will be further described for simplicity. The brake pad20and the backing plate26together comprise a brake pad assembly of the vehicle brake caliper assembly10. Therefore, the vehicle brake caliper assembly10includes the brake pad assembly having the brake pad20and the backing plate26. As the brake pad20is made from a frictional material that regularly engages the rotor14, the brake pad20is subject to being worn down over time. Eventually, the brake pad20is susceptible to becoming too thin to function properly when the frictional material is worn away and braking can become compromised.

Traditionally, measuring a brake pad thickness requires a series of complicated steps, including removing the tire18, identifying the caliper24and removing the bolts on the caliper24. The caliper door can then be opened in order to access the brake pads20and22. The brake pads20and22are then removed for measuring. The complicated technique increases the cost of service for brake pad replacement at the dealership, particularly if the brake pads20and22are removed and measurement finds that no replacement is necessary. In these circumstances, the dealership absorbs the lost labor cost of disassembling the brake caliper assembly10.

Therefore, a brake pad dimension estimation system30is provided in accordance with an illustrated embodiment. The brake pad dimension estimation system30is designed to be non-invasive such that it is not necessary to disassemble the tire18, the caliper24or the brake pad20from the brake caliper assembly10. In particular, the brake pad dimension estimation system30of the illustrated embodiment utilizes an optical approach to estimate a thickness of the brake pads20and22using captured images of the brake pads20and22. By eliminating the need to disassemble the brake caliper assembly10, the brake pad dimension estimation system30provides an accurate technique for estimating a thickness of the brake pad20such that the technique can be routinely implemented at regular vehicle servicing appointments at low cost. Therefore, disassembling of the brake caliper is necessary only when the brake pad dimension estimation system30finds that the brake pad thickness is too low. For example, if the brake pad dimension estimation system30finds that the brake pad20is three to four (3 to 4) millimeters in thickness, then the dealer can determine that the brake pads20and22are at the end of their lifespan and replacement is necessary.

In the illustrated embodiment, the term “thickness” of the brake pad20refers to a dimension of the brake pad20measured along a direction T that is parallel to the axle16when the brake caliper having the brake pads20and22is installed to the vehicle12, as best seen inFIG.3. In the illustrated embodiment, while the brake pad dimension estimation system30can be utilized to measure both the first and second brake pads20and22, only measurement of the first brake pad20(outside brake pad20) will be further described for simplicity. In application, the measurement result of the first brake pad20can be used to infer the thickness of the second brake pad22such that direct measurement of the second brake pad22is not necessary.

As best seen inFIGS.1and2, the brake pad dimension estimation system30comprises a detecting device32and an electronic controller ECU. The brake pad dimension estimation system30further comprises a display34in electronic communication with the electronic controller ECU. The electronic controller ECU is programmed to control the display34to display a warning indication when the thickness of the brake pad20is determined to be below a threshold thickness value, as will be discussed below.

The detecting device32is configured to obtain dimensional information from an image of the brake pad assembly. The detecting device32includes a camera36configured to capture the image of the brake pad assembly (the brake pad20and the backing plate26). The detecting device32can alternatively utilize radiation or ultrasound to capture the image of the brake pad assembly. The detecting device32can alternatively utilize light detection and ranging (LIDAR) to capture image information of the brake pad20. The electronic controller ECU can create a 3D image of the brake pad20based on information detected using LIDAR to determine the thickness of the brake pad20.

As shown, the detecting device32is preferably a wireless endoscope having an optical probe or the camera36. The detecting device32is illustrated as an automotive endoscope that has a flexible optical cable38that can be manipulated along the brake caliper assembly10. The detecting device32is in wireless communication with the electronic controller ECU that determines the thickness of the brake pad20, as will be further discussed.

In the illustrated embodiment, the electronic controller ECU is part of a mobile device40that is in wireless communication with the detecting device32. In the illustrated embodiment, the mobile (external) device is provided to be used with the detecting device32. Examples of the mobile device40include a smartphone, a tablet or a personal computer. The detecting device32is equipped with a wireless communicator32A and the electronic controller ECU is equipped with a corresponding wireless communicator40A. The wireless communicator32A of the detecting device32and the wireless communicator40A of the mobile device40are preferably disposed on a respective printed circuit board PCB that is disposed in the mobile device40and the detecting device32. The wireless communicators32A and40A can be equipped with Bluetooth technology, including Bluetooth low energy, Wi-Fi, or include the wireless protocol ANT+.

The term “wireless communicator” as used herein includes a receiver, a transmitter, a transceiver, a transmitter-receiver, and contemplates any device or devices, separate or combined, capable of transmitting and/or receiving wireless communication signals, including shift signals or control, command or other signals related to some function of the component being controlled. The wireless communication signals can be radio frequency (RF) signals, ultra-wide band communication signals, or Bluetooth communications or any other type of signal suitable for wireless communications as understood in the vehicle field. Here, the wireless communication communicator can be a two-way wireless communication unit having a receiver and a transmitter.

Preferably, the mobile device40includes at least one software application that is installed to detect, measure, store and/or send information regarding the dimension of the brake pad20. Therefore, the electronic controller ECU is in electronic communication with the detecting device32to receive the dimensional information from the image of the brake pad assembly. That is, the detecting device32can upload image data to the mobile device40to be processed by the electronic controller ECU in the mobile device40. The electronic controller ECU is programmed to determine a dimension (the thickness) of the brake pad20based on the image.

The electronic controller ECU is capable of processing the images captured by the detecting device32. The electronic controller ECU includes a processor42for processing data captured by the detecting device32. For example, the images captured by the detecting device32can be processed to generate images by video codec(s), and/or the processor42, and/or graphics hardware, and/or a dedicated image processing unit incorporated within the camera36circuitry. The mobile device40preferably includes memory or storage44for storing programs and processes as will be discussed below. The images captured by the detecting device32be stored in the memory and/or the storage44of the mobile device40. The memory can include one or more different types of media used by processor42, graphics hardware, and image capture circuitry to perform device functions. For example, memory may include memory cache, ROM, and/or RAM.

The storage44of the mobile device40can be any a non-transitory computer readable medium such as a ROM device, a RAM device, a hard disk, a flash drive, cloud drive, etc. The storage44is configured to store settings, programs, data, calculations and/or results of the processor(s)42. That is, the electronic controller ECU can include a program or an application that controls the detecting device32to capture the image of the brake pad20.

In the illustrated embodiment, the electronic control unit ECU can as be provided with the mobile device40. The electronic control unit ECU can alternatively be provided as part of an external server or a remote server, as seen inFIG.1. For example, the processing and computing operations described for the electronic control unit ECU herein can alternatively be performed on a cloud C. That is, the programs and applications for estimating the brake pad thickness can be stored on the cloud C which the mobile device40can be connected to. The electronic control unit ECU can therefore be a central processing unit CPU of the cloud C so that the computation for the brake pad thickness is performed on the cloud. For simplicity, the electronic control unit ECU will be hereafter described as being part of the mobile device40.

In the illustrated embodiment, the storage44is configured to store at least one reference image and/or thickness of the brake pad20. More particularly, the storage44is configured to store a plurality of reference thickness values R1(e.g., R1A and R1B). For example, the storage44can store images of brake pads of varying thickness values that can be used as reference for comparison to the detected values obtained by the detecting device32. Therefore, the mobile device40includes pre-stored reference thickness values R1A that will be used to determine the thickness of the brake pad20. For example, the storage20can store known thickness values of brake pads of different brands, makes and manufacturers (labeled as R1A inFIG.8). More preferably, the storage44preferably stores an image library having a plurality of reference brake pad images R1B for comparing to the captured image of the brake pad20. As seen inFIG.8, a sample dataset of prestored reference thickness values R1is illustrated. As shown, the sample dataset can include either reference images or known thicknesses of the brake pads. Therefore, the reference thickness values R1can include either reference images or known thicknesses of the brake pads depending on type, brand or manufacture, etc.

The storage44can also store non-transitory computer readable media (e.g., audio, image and video files), computer program instructions or software, preference information, device profile information, and any other suitable data. The storage44preferably further contains convolutional neural networks (CNN) or other types of image recognition/processing software. The memory and/or the storage44can be used to retain computer program instructions or code organized into one or more modules and written in any desired computer programming language. The processor42of the electronic controller ECU can execute such computer program code by implementing one or more of the methods described herein.

As shown inFIGS.4to7, the mobile device40further includes an electronic display34that can display information regarding the reference images that are prestored in the storage44, and/or live images captured by the detecting device32. The electronic display34can further display other information accessible by the processor42of the electronic controller ECU. The electronic display34is preferably a touchscreen that is an assembly of both an input (‘touch panel’) and output (‘display’) device. The touch panel is normally layered on the top of an electronic visual display of an information processing system. The electronic display34can be an liquid-crystal display (LCD), active-matrix organic light-emitting diode (AMOLED) display, or an organic light-emitting (OLED) display.

The user can give input or control the information processing system through multi-touch gestures by touching the screen with a special stylus or one or more fingers. The user can use the touchscreen to react to what is displayed and, if the software allows, to control how it is displayed; for example, zooming to increase the text size. As stated, the electronic controller ECU is programmed to control the electronic display34to display a warning indication. The warning indication can include text such as “the brake pad20needs replacement” or “the brake pad20will need replacement soon.”

The processor42of the electronic controller ECU can be any suitable programmable control device capable of executing instructions necessary to carry out or control the operation of the many functions performed by the mobile device40(e.g., such as the processing of images captured by the detecting device32and/or infrared imaging or ultrasound). The processor42can, for instance, control the electronic display34and receive user input from user interface which can take a variety of forms, such as a button, keypad, dial, a click wheel, keyboard, display screen and/or a touch screen. The processor42can be a system-on-chip such as those found in mobile devices and include a dedicated graphics processing unit (GPU).

The processor42can be based on reduced instruction-set computer (RISC) or complex instruction-set computer (CISC) architectures or any other suitable architecture and may include one or more processing cores. The mobile device40is preferably further equipped with graphics hardware such as special purpose computational hardware for processing graphics and/or an assisting processor42to process graphics information. The graphics hardware can include one or more programmable graphics processing units (GPUs).

Referring toFIG.2, the brake pad dimension estimation system30can further comprise an alignment bracket46that can be used for estimating the brake pad thickness. In particular, the alignment bracket46can be used to help guide the detecting device32to capture the image of the brake pad20for measurement. As shown, the alignment bracket46can be a telescoping rod having an adjustable length. As shown, the alignment bracket46is removably attachable to the wheel across a diameter length of the wheel. When the alignment bracket46is mounted to the vehicle wheel, the alignment bracket46forms a reference line to guide the user of the detecting device32to operate the detecting device32to capture the image of the thickness of the brake pad20. In particular, the user preferably directs the optical cable38to extend at a direction that is orthogonal to the alignment bracket46.

In particular, the user optimally guides the optical cable38at a ninety degree angle relative to the alignment bracket46towards the brake caliper assembly10. In this way, the optical probe can capture an image of the brake pad20that is tangential to the curve of the brake pad20, as schematically shown inFIGS.1to3.

In the illustrated embodiment, a method for estimating a brake pad20dimension is disclosed. The method comprises arranging the alignment bracket46to the vehicle brake caliper assembly10along the diameter length of the vehicle brake caliper assembly10. The method further comprises arranging the detecting device32with respect to the vehicle brake caliper assembly10along a direction that is orthogonal to the alignment bracket46. The method for estimating the brake pad20dimension also comprises arranging the detecting device32with respect to the vehicle brake caliper assembly10so that the detecting device32captures an image of the brake pad assembly along a direction D that is substantially tangent to the outer curve of the brake pad assembly, as best seen inFIGS.1and2.

Thus, the method further comprises capturing the image of the brake pad assembly along the direction D that is substantially tangent to the curve of the brake pad assembly. The method further comprises using the mobile device40to determine the thickness of the brake pad assembly based on the captured image of the brake pad assembly. As seen inFIG.7, the method of further comprises operating the mobile device40to select the brake pad type, such as the brake pad brand name, the manufacturer of the brake pad or the location of the brake pad. The electronic control unit ECU can then determine the degree of wear of the brake pad20by comparing it to reference thickness values R1depending on the brand, manufacturer or location of the brake pad.

As will be further described, the means for determining the thickness includes software or programs that are installed onto the mobile device40or alternatively in the cloud C with which mobile device40communicates. In the illustrated embodiment, the means for determining the thickness of the brake pad20includes using either the backing plate26as a reference thickness value for determining an erosion of brake pad20, or using pre-stored brake pad thickness values as reference thickness values for determining the erosion of the brake pad20. Thus, the means includes one of using a measured thickness of the backing plate26of the brake pad assembly and using a prestored brake pad reference thickness value R1, as will be further described below.

Referring, toFIGS.5to8, the electronic controller ECU is programmed to calculate a dimension of the brake pad20with respect to a dimension of the backing plate26. As stated, the backing plate26is a metal plate preferably made out of steel while the brake pad20is made from a frictional material that can be worn down over time. Therefore, the backing plate26has a constant thickness while the brake pad20has a variable thickness. The electronic controller ECU can be programmed to estimate the thickness of the brake pad20based on a ratio of the thickness of the brake pad20with respect to the thickness of the backing plate26. Therefore, the electronic controller ECU is programmed to calculate a ratio of the thickness of the backing plate26with respect to the thickness of the backing plate26.

When the ratio falls below a predetermined ratio that is a threshold value R2, then the electronic controller ECU can control the electronic display34to display the warning indication to the user. Therefore, the electronic controller ECU is programmed to control the display34to display the warning indication when the calculated ratio is below the predetermined ratio. The storage44of the electronic controller ECU therefore preferably stores the predetermined ratio. Therefore, the storage44stores the predetermined ratio of the thickness of the backing plate26with respect to the thickness of the backing plate26. The electronic controller ECU is programmed to compare the calculated ratio to the predetermined ratio in order to determine whether the calculated ratio falls below the predetermined ratio that is stored in the storage44.

In the illustrated embodiment, the storage44can alternatively contain one or more reference images of the brake pad20and/or the backing plate26, as seen inFIG.8. The electronic controller ECU can be programmed to compare the captured image of the brake pad20to either one of the reference images of the brake pad20and/or the backing plate26to determine a ratio of the thickness of the brake pad20with respect to the thickness of the reference images. The reference images can include reference images of different types of brake pads20and22. Alternatively, the reference images can include reference images of a brake pad20assembled to a backing plate26and/or a brake caliper.

Preferably, the electronic controller ECU is programmed to determine an average thickness of the brake pad20based on the captured image of the brake pad20. For example, the electronic control is programmed to measure a thickness of brake pad20along multiple points on the captured image of the brake pad20, for example as seen inFIG.6. For example,FIG.6schematically illustrates a series measurements that extend across the curved edge of the brake pad20which can be utilized by the electronic controller ECU to determine an average thickness based on the series of measurements. The electronic controller ECU is programmed to determine an average thickness based on the measured thicknesses. The average thickness is used for the ratio comparison with respect to the backing plate26. Preferably, the electronic controller ECU is programmed to determine the thickness of the brake pad20at several locations along the length of the brake pad20.

Referring now toFIGS.6to9, the electronic controller ECU is preferably further programmed to compare the dimensional information of the brake pad20captured by the detecting device32with a selected one of the reference brake pad thickness values R1. That is, the user can alternatively select a means the brake pad's 20 type, as seen inFIG.7, for pulling up the reference brake pad thickness values. Therefore, the storage44of the electronic controller ECU can store a plurality of reference brake pad thickness values R1. For example, the storage44can be prestored with a variety of known brake pad20types or brands. The user can select the brake pad20type or brand that is installed onto the brake caliper assembly10, such as by selecting one of a plurality of images as seen inFIG.8. Therefore, in the illustrated embodiment, the reference thickness value(s) R1can be based on prestored images of different types of brake pads.

The electronic controller ECU can measure the brake pad thickness based on multiple points (measurements) in the image and use the measured values to calculate the average thickness, as described above. As shown in Figure, the electronic controller ECU measures thickness of the brake pad20at points P1to P6to illustrate varying measurement points that can be taken along the brake pad20to determine the average thickness of the brake pad20. The electronic controller ECU is programmed to calculate the ratio of the thickness of the brake pad20to the selected one of the reference brake pad thickness values R1to determine whether the brake pad20falls below a predetermined threshold value R2. Alternatively, the electronic controller ECU is programmed to compare the calculated ratio to the selected one of the reference brake pad thickness values R1directly. The electronic controller ECU is programmed to control the display34to display the warning indication when the calculated ratio is below the predetermined threshold value R2.

In the simplest embodiment, the electronic controller ECU can be programmed to measure a thickness of the brake pad20and compare the measured thickness to the pre-stored threshold thickness value R2, such as three to four (3 to 4) millimeters. That is, a typical brake pad20has a thickness of approximately ten to twelve (10 to 12) millimeters. When the electronic controller ECU determines that the measured thickness of the brake pad20is approximately five to six (5 to 6) millimeters, the electronic controller ECU can control the display34to display an alert indication to the user that the brake pad20may need replacement soon. When the electronic controller ECU determines that the measured thickness of the brake pad20is approximately 3 to 4 millimeters, the electronic controller ECU can control the display34to display a warning indication that the brake pad20needs replacement immediately.

Therefore, the electronic controller ECU can be programmed to store a plurality of threshold thickness values R2(e.g., 5 to 6 millimeters, or 3 to 4 millimeters). When the measured thickness of the brake pad20falls below the threshold thickness values R2, the display34can display different types of indications to the user indicating that replacement is soon or immediately necessary. Thus, in the simplest embodiment, the threshold thickness value R2can be the same as the reference thickness value R1for direct comparison to the measured values of the brake pad20.

Referring now toFIG.9, a process of the electronic controller ECU is illustrated in accordance with an illustrated embodiment. In step S1, the brake pad dimension estimation system30can be initiated by the user opening a program or an application in the mobile device40. In step S2, the electronic controller ECU of the brake pad dimension estimation system30obtains the image of the brake pad assembly from the detecting device32(the camera36). As stated, the mobile device40is in wireless communication with the detecting device32. Therefore, the mobile device40wireless receives the image data from the detecting device32.

In step S3, the electronic controller ECU can control the display34to display a preferred measurement method, such as either using a thickness of the backing plate26as a reference for comparison or using images of brake pads with varying thickness values as a reference for comparison. The display34can display a message similar to that shown inFIG.4. In step S4, based on the user's selection, the electronic controller ECU can select the preferred method for estimating the brake pad thickness.

In step S5, the electronic controller ECU measures the thickness of the brake pad20based on the captured image from the detecting device32. As stated, the electronic controller ECU preferably measures the thickness of the brake pad20at several points P1to P6along the brake pad20and calculates an average thickness, as seen inFIG.6. In step S6, the electronic controller ECU compares the measured thickness (or the average of the measured thickness values) to any of the prestored reference thickness values R1A or the prestored images R1B that have been discussed. In step S7, the electronic controller ECU determines a ratio based on the comparison obtained in step S6.

In step S8, the electronic controller ECU determines whether the ratio determined in step S7falls below the predetermined threshold value R2. For example, the electronic controller ECU can determine that the brake pad thickness is less than half of the thickness of the backing plate26. Alternatively, the electronic controller ECU can determine that the brake pad thickness is less than half of the brake pad thickness values that are prestored in the storage44. If the electronic controller ECU determines that the brake pad thickness does fall below the threshold value, then the electronic controller ECU can control the display34to display a warning indication or message to the user in step S9. If the electronic controller ECU determines that the brake pad thickness does not fall below the threshold value then the system ends in step S10.

With the brake pad dimension estimation system30, the electronic control unit ECU is programmed to achieve the technical improvement of enhanced estimation of brake pad dimensions using image information captured by the detecting device. Further, the electronic control unit ECU is programmed to compare reference information and data (e.g., as shown inFIG.8) to image data captured by a camera to achieve the technical improvement of enhanced prediction, estimation and calculation of a brake pad dimension.

The term “detect” as used herein to describe an operation or function carried out by a component, a section, a device or the like includes a component, a section, a device or the like that does not require physical detection, but rather includes determining, measuring, modeling, predicting or computing or the like to carry out the operation or function.