Abstract:
A tire tread depth measurement system includes a scanner and smart phone that fit into the palm of a user either directly or attached to a glove. The technician obtains tread depth data by moving her hand holding the scanner over a tire profile. The scanner communicates with a nearby control box that uploads the data to a server for determination of tread depth, tire wear pattern and wheel alignment. The tire tread analysis is downloaded to the control box and reported to the technician via the smart phone. The smart phone is programmed to identify the vehicle and related information about it based on the license plate or vehicle identification number by interpreting the license number or VIN and interrogating various data bases via the internet. Wear and analysis results are forwarded for printing the entire report.

Description:
BACKGROUND 
       [0001]    Tire tread depth is a safety issue Worn tires have little traction especially on wet roads. Visual inspection or tire tread depth measurements may be made to determine the amount of tread left on a tire. However, tires may wear down to an unsafe level unless checked with sufficient frequency so that the rate of tire tread wear can be properly ascertained for a good prediction of the end of useful tire service. 
         [0002]    Tire tread depth also affects fuel economy. Vehicular fuel economy is directly affected by resistance to movement, including rolling resistance. Underinflated tires increase rolling resistance and increase fuel use per unit distance. Tire tread depth measurements and wear patterns reveal issues in maintaining tire inflation at proper levels. 
         [0003]    There are several devices for measuring tire tread depth including handheld devices and drive-over devices. These are useful and convenient but there remains a need for improvement. 
       SUMMARY OF THE INVENTION 
       [0004]    The present invention is a tire tread depth measurement system that includes several components. It includes a hand-held tread depth scanner; that is, a scanner that is held in the palm of the hand either directly or attached to a glove worn on or attached to the hand of the user. The present invention may also include a smart phone. The technician holding the scanner can obtain data related to tire tread depth for each tire on a car or truck by moving the scanner over the running surface of the tire. The tread depth scanner carried by the hand of the user communicates with a controller located in a nearby tire replacement facility which then uploads the scanned data to the “cloud” where it may be accessed for calculation of tread depth and a determination as to the character of tire wear. These results are forwarded to a printer in the tire replacement facility and, optionally, to a smart phone operated by the tire technician or, alternatively, to the primary components of the smart phone installed with the scanner. 
         [0005]    The hand held scanner is programmed with a software application enabling the technician to identify the vehicle. For example, the technician may take an image of the license plate of the vehicle or scan the vehicle identification number bar code using a camera on the smart phone or one installed directly on the scanner or on the glove to which the scanner is attached. The license plate text is read and then associated with the vehicle identification number via access to a database that relates plate text to identification numbers. The vehicle identification number is then associated with the vehicle make, model, year, and factory-installed tire size. The vehicle identification number, when obtained using the license plate, and the other information are all available by automatic interrogation of various databases accessible via the internet. This information is also forwarded to a controller that associates the information with the tire tread depth data when that data is transmitted to cloud-based software for analysis. 
         [0006]    The tire tread analysis is downloaded from the cloud to the controller and an reported to the technician to share with the owner of the vehicle. The full results of that analysis and record are also forwarded to a printer to print a paper copy of the tire report. The full report, in addition to including numerical tread wear results, contains images of the actual measured tire profile against a new tire profile so the extent of wear and pattern of wear are easily perceived. Furthermore, the report provides an analysis of the wheel alignment, increased braking distance in view of tire wear, and administrative information such as time, date, dealer name, and so forth. 
         [0007]    The use of the user&#39;s palm as a platform for the tire tread measurement device improves productivity over so-called hand-held devices because the technician holding it can readily sense the surface of the tire, and can position the tread depth measuring device with respect to that surface, and move across the surface of a tire more efficiently with the hand than with a probe on the end of a handle. The palm of the hand can quickly conform the scanner to the surface of the tire in a basic manual inspection. The palm-held scanner also avoids the need to drive a car over a tread measuring scanner, which, while quick and efficient in certain applications, requires movement of the car. 
         [0008]    The combination of a tire tread depth measurement device and a smart phone, in a first embodiment, takes advantage of the compact telecommunication capabilities, graphical user interface, programmed internal processor, as well as a digital camera of the smart phone, to facilitate the acquisition, storage, processing, and communication of data so that results are obtained and reporting quickly. In the second embodiment, the key features of the smart phone are incorporated into the scanner itself. Furthermore, the present tread depth measurement system requires only modest training to use. 
         [0009]    These and other features and their advantages will be apparent to those skilled in the art of tire tread depth measurement from a careful reading of the Detailed Description of Embodiments, accompanied by the following drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    In the figures, 
           [0011]      FIG. 1  is a perspective top view of an embodiment of a glove for use in measuring tread depth, according to an embodiment of the invention; 
           [0012]      FIG. 2  is top view of the user interface of the glove of  FIG. 1  with tire tread measuring capability, according to an embodiment of the invention; 
           [0013]      FIG. 3  is an interior view of a tire depth scanner showing the major components thereof, according to an embodiment of the present invention; 
           [0014]      FIGS. 4A-4E  are a series of views of a mobile device such as a smart phone, according to an embodiment of the present invention, showing the icon  76  for the present tire tread depth measurement software application resident on the mobile device in  FIG. 4A ; the software application user login page in  FIG. 4B ; the optional choices for the technician supported by the launched software application in  FIG. 4C ; the user interface for manual data entry in  FIG. 4D ; and, in  FIG. 4E , the tread wear report provided by the software application; 
           [0015]      FIG. 5  is a schematic diagram of a part of the tread depth measurement process and the tire profile; 
           [0016]      FIG. 6  is a diagram showing the components of the present method and the flow of information among them, according to an embodiment of the present invention; 
           [0017]      FIG. 7  is a perspective view of an alternative embodiment of the glove, according to the present invention; 
           [0018]      FIGS. 8A and 8B  show bottom view of two alternative embodiments of the glove illustrated in  FIG. 7 ; 
           [0019]      FIGS. 9A and 9B  show an alternate embodiment of a top view of scanner and the back view of the scanner that is held directly in the palm of the user, according to an embodiment of the present invention; and 
           [0020]      FIG. 10  illustrates the operation of the alternative embodiment of the present scanner, according to an embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0021]    The present tread depth measuring device is a scanner dimensioned to be held in the palm of a hand, and in one embodiment, is attached to a glove. The tread depth measuring device serves as a handle, platform and positioning device for two single-point triangulation lasers. The measuring device may also carrt a camera, Wi-Fi telecommunications equipment, a processor and a user interface. 
         [0022]    The term hand held or palm held is used to mean a device that is placed in the palm of the hand and covers the palm, is easily operated by the fingers and may be mounted to a glove worn on the hand. The term is intended to describe a device operated specifically as if part of the hand because of how it relates to the palm of the hand because it uses the developed hand eye coordination intrinsic to users to position and maneuver the device. Its form and position in use is intended to take advantage of the natural dexterity of the human hand in manipulating the functional elements carried by the measuring device over the surface of a tire. As the technician moves his or her hand across the running surface of the tire, the tread depth is scanned by lasers in the device which acquire data representing the distance between the surface of the tire and the bottom of the tire grooves. The hand is naturally adapted for movement that conforms to the tire surface and readily detects its orthogonal curves, orienting naturally to find the right one to traverse. 
         [0023]      FIG. 1  shows an embodiment of the present measuring device as part of a glove  10  when viewed in perspective from the top left as opposed to a view of the palm of glove  10 . Glove  10  may have finger loops  12 ,  14 , and a wrist strap  16  on the back that secure a tread depth scanner  18  to the user&#39;s palm and also position the user&#39;s fingers with respect to a user interface  20  on the back of glove  10  for operating scanner  18 . 
         [0024]      FIG. 2  shows an enlarged view of user interface  20 . User interface  20  has a start button  24  on the left that, when pressed, starts tread depth scanner  18  through a cycle. Button  24  will be operated by the technician&#39;s index finger while wearing glove  10  on the right hand. Button  24  may be a “press and hold” button that powers the scanner  18  on when pressed and held, and stops them only when released. A measurement cycle begins by pressing button  24  and holding it while the technician passes his hand that is wearing glove  10  over the running face of tire, that is, from side to side, orthogonal to the circumference of the tire, and ends when button  24  is released. 
         [0025]    As best seen in  FIG. 2  Interface  20  also has tire-indicating LEDs  28  (light emitting diodes) used as icons for selecting front tires, and LEDs  32 , as icons for selecting rear tires. The additional two LEDs  32  permit scanning of two additional rear tires if the vehicle is a six-tire vehicle. LEDs  28  and  32  may be oval in shape to represent the appearance of tires. Note that the relative positions of LEDs  28  and LEDs  32  measurements correspond to the locations of tires of a vehicle, that is, the front left tire of the vehicle may be associated with the top left LED  28  so that the data recorded when LED  28  is selected and start button  24  is pressed corresponds to the front left tire on the vehicle and can be presented as a tread depth measurement associated with the correct tire. Similarly, when the second LED  32  from the right is selected and start button  24  is pressed, the user should be measuring the right rear tire of a four-tire vehicle. 
         [0026]    A button  36 , carrying a right-pointing arrow lights each of the tire LEDs  28 ,  82  in a rotating sequence. Each press of button  36  lights the next LED  28 ,  32 . Button  36  may conveniently be activated by the ring finger when wearing glove  10  on the right hand. Interface  20  will not automatically advance from one tire LED  28 ,  32 , to the next unless button  36  is first released and then pressed. 
         [0027]    The button labeled 4/6, button  40 , is a toggle button that enables the technician to select between a four-tire and a six-tire configuration by repeatedly pressing button  40 . Both LEDs  28  and two LEDs  32  flash when four-tire configuration is selected by toggling button  40 , and, after toggling button  40  again, all six LEDs  28 ,  32 , flash to indicate a six-tire vehicle has been selected. Another press of button  40  returns to a four-tire configuration, and, once again, both LEDs  28  and the middle two of four LEDs  32  flash. 
         [0028]      FIG. 3  shows the major components inside tread depth scanner  18 . Inside scanner  18  is a pair of lasers  44  that direct their light to their respective mirrors  48  and thence through glass windows  52 . A beeper  56  confirms scanning has started and again when a cycle has been completed, and corresponds to the pressing and releasing, respectively, of start button  24  of user interface  20 . Batteries  60  provide electrical power to energize lasers  44  and for communication of received data wirelessly through both radio modem transmitter  64  such as that manufactured by Bluetooth Sig., Inc. and sold under the trademark BLUETOOTH, and a wireless transmitter  68  operating under IEEE standard 802.11 such as that certified by the Wi-Fi Alliance. 
         [0029]      FIGS. 4A-4E  illustrate five successive screen images of a smart phone  72 . A smart phone is defined as a hand held computer with telecommunications capability, processor, battery, and a graphical user interface, such as IPHONE manufactured by Apple, Inc., and smart phones using the ANDROID operating system as manufactured by Samsung Electronics Company Ltd. A software application is installed on smart phone  72 , preferably an application that operates on any brand of smart phone, to enable smartphone  72  to communicate data and display results according to the present method. Turning on smart phone  72  will cause an icon  76  for that application to appear among other applications resident on the processor of smart phone  72  so that a technician may launch the software in accordance with the user interface protocols of the particular brand of smart phone  72  used. 
         [0030]    Once the application is launched, a login page ( FIG. 4B ) page appears with a text box  200  for identification of the technician using the present software. After logging in, the technician may select at  FIG. 4C  from among several options to identify the vehicle  202  the tires of which are to be measured for tread depth, including scanning a vehicle identification number barcode or license plate using the smart phone camera. The technician may alternatively access recent activities  204 , search for previous measurements  206 , search on previous users  208  of the application, and adjust settings  210 , for example, changing from metric to English units or choice of Wi-Fi network. There is also a “help” button  212 . 
         [0031]    In  FIG. 4D , the manual input screen that has a text box  94  for entering either the license plate or vehicular identification number using a keyboard  216  of smart phone  72  as shown. 
         [0032]      FIG. 4E  illustrates the display of tread depth measurement results on smart phone  72 . The tread depth of each tire is provided adjacent to each tire icon  218 ,  220 ,  222 , and  224 . Each tire icon  218 ,  220 ,  222 ,  224 , is labeled for its position on the vehicle: LF for left front, LR for left rear, RF for right front, and RR for right rear for a four-tire configuration. Each tire icon  218 ,  220 ,  222 ,  224 , is ringed with a color as a cue to the status of each tire, using the familiar colors of green, yellow, and red for satisfactory, caution, and replace, respectively. The colors correspond to ranges of tread depth. 
         [0033]    In addition, if the tires are misaligned, that information is provided with a warning sign below icons  218 ,  220 ,  222 ,  224 . 
         [0034]    Scanning a tire with a handheld device requires information as to the location of the device at each point across the tire profile in order to obtain the tread depth as a function of position as scanner moves across the running surface of the tire. 
         [0035]    Micro-Electro-Mechanical Systems (MEMS) could provide data for measuring that movement, but this would introduce errors, especially when the movement is slow. Alternatively, a camera or an optical mouse could be used to measure movement, with the tire itself as a reference. In this case the measured value would depend on the distance between the camera or mouse and the tire with its accompanying error. Moreover, image processing would be necessary. 
         [0036]    An optical mouse might also provide the measurement but would require special optics and illumination in order to work at a reasonable distance, such as at least a couple of mm. 
         [0037]    The present approach uses two triangulation laser sensors and signal processing. Two laser distance sensors  80 ,  84 , are moved across a tire profile  88  and the distance measured is recorded. As they are moved across profile  88 , each sensor  80 ,  84 , reaches surface feature  92 ,  96 ,  100 ,  104 ,  106  at different times. That time differential can be measured. If the distance between sensors  80 ,  84  is known, the instantaneous velocity of the sensors  80 ,  84 , can be calculated at each feature  92 ,  96 ,  100 ,  104 : at the beginning of the tire  92 , at every groove  96 ,  100 , and  104 . 
         [0038]    The velocity curve of the hand holding the scanner, with or without glove  10 , moving across the tire can be reconstructed from this information. From the velocity curve, the X-position of every measured feature can be calculated. An inertial pack consisting of an accelerometer and gyroscope may be incorporated into the unit to adjust for tremors or jerky hand movements of the operators hand during tread scan. Their output can correct the data for these movements mathematically to produce more accurate results. Both the accelerator and gyroscope require careful factory calibration 
         [0039]    For the embodiment in which scanner  18  is carried by glove  10 , a technician assigned to measure tread depth on the tires of a vehicle  76  dons glove  10 , inserting the index and middle fingers of the right hand into loops  12 ,  14 , respectively, and fastening strap  16  to his wrist. By inspection, the technician determines that vehicle  76  has four tires and toggles button  40  until both LEDs  28  and two of four LEDs  32  flash. 
         [0040]    The technician enters the license plate number or the vehicle identification number (VIN), or both, into smart phone  72 , and vehicle mileage into the text window on its input screen ( FIG. 4D ). Next, the technician selects a tire to measure and uses right arrow button  36  on user interface  20  to scroll through until the corresponding LED  28 ,  32  lights. The technician then positions tread depth scanner  18  on the inside shoulder of the first tire with glove  10  on his hand, and presses and holds start button  24  on user interface  20  on back of glove  10  and moves his gloved hand across the tire from the inside shoulder to the outside shoulder in 2 to 3 seconds as a measurement point is recorded for every feature on tire surface. The technician then proceeds to each tire in turn to measure the tread depth of each of the other tires of vehicle  76  by repeating this procedure. 
         [0041]    Importantly, the use of a glove  10  as a platform for a scanner  18  allows the technician to measure tread depth with one hand and, more importantly, to take advantage of the palm of the hand&#39;s inherent ability to find an object and assess the shape of a surface, particularly in low light such as is the case in a wheel well. The hand, bare or gloved, is sensitive to surface features and shape. That surface-sensing capability defers to the technician&#39;s eyes when the technician is using a hand held device. In low light conditions, however, such as in a wheel well, the technician&#39;s eyes are challenged to position the handheld device accurately. In the present device, the use of the palm as the position for scanner  18  preserves the hand&#39;s function as a sensor of location. Carrying scanner  18  on glove  10  may protect the technician&#39;s hand from injury and dirt but without decreasing sensitivity. 
         [0042]    As shown in  FIG. 6 , the tread depth data output from scanner  18 , transmitted via wireless transmission to a nearby controller  112 , such as Wi-Fi or Bluetooth. Wi-Fi is preferred for range and reliability. In the embodiment of glove using a cell phone, Bluetooth is the preferred connection. The vehicle identification information is used by smart phone  72  to access and interrogate various databases for information about the vehicle, such as make, model, year, and factory-installed tire size. This information is also forwarded by radio modem transmission to controller  112 . The data regarding tread depth and the vehicle information is forwarded from controller  112  to analytical software resident on remote servers that are in the “cloud” for analysis and results. The cloud and cloud computing refer to a model of network computing where a program or application runs on a connected server or servers rather than on a local computing device, but, in cloud computing, the computing process may run on one or many connected computers at the same time and therefore provides greater flexibility and speed. Here, use of cloud computing servers  116  is also assures that each location where tread depth is being measured using the present system is always operating using the current software version. 
         [0043]    Servers  116  transmit reports back to controller  112  and smart phone  72 . The report provided to smart phone  72  is explained above in connection with  FIG. 4E . However, the report transmitted to controller  112  and then printed by printer  108  contains more information and presents the results graphically. For example, the administrative information of time, date, facility name and location are provided along with the vehicle&#39;s make, model, year, and tire size. Tread depth is shown graphically in the report as a profile of the worn tire along with the tire profile of a new tire that that particular vehicle for ease of comparison. Tire misalignment is identified. 
         [0044]      FIG. 7  illustrates an alternative embodiment of the present glove, generally indicated by reference number  130  one that is similar to that shown in  FIG. 1 . Glove  130  is very similar from the top to glove  10  but user interface  134  may be different, limited to a power button  138  to turning on laser distance sensors  80 ,  84 . Glove  130  also has a camera  142  mounted on the tip so that the technician of glove  130  can simply point to an object such as a license plate or vehicle identification number and press camera button to capture an image. Glove  130  may alternatively have a pair of opposing power buttons  144  located on the sides  140  of glove  130  that must be held simultaneously to activate laser sensors  80 ,  84 . If glove  130  is dropped, the user will have release the opposing buttons  144  and thereby provide some protection for the lasers which are more likely to be damaged if left on when dropped. 
         [0045]      FIGS. 8A and 8B  are two alternative embodiments of a scanner  146 . A first one, illustrated in  FIG. 8A  shows a second user interface  150  similar to interface  20  in that it has a start button  154 , a 4/6 button  158  to select four- or six-tire configurations for measurement, and a tire selection button  162  that scrolls from LED to LED of the four or six tire configuration to select the particular tire for measurement. The second embodiment, illustrated in  FIG. 8B , replaces the user interface of the smart phone  72  with one on scanner  146 , so that the technician can log in and vehicle identification can be done by scanner  146  in a manner similar to that explained above in connection with smart phone  72 . Scanner  146  will access the internet via Wi-Fi to identify the make, model, year, and tire size of the vehicle. The interior components of scanner  146  in either embodiment are otherwise the same as those of scanner  18 , as described above, for performing tread depth measurements. 
         [0046]      FIG. 9A  illustrates an alternative embodiment for the back of glove  130  to that shown in  FIG. 7 . Instead of finger loops  12 ,  14  and strap  16 , a glove  166  has a strap  170  that covers the back of the palm of the user holding scanner  130  to the hand. Alternatively, as seen in  FIG. 9B , scanner  146  may have no strap  170  but be held by the palm of the user&#39;s hand. User interface is near the user&#39;s fingers as is a camera button  168  for obtaining a photographic image of a license plate or vehicle identification number. In this embodiment, a pair of opposing power buttons  172  located on the sides of scanner  146  must be depressed simultaneously to activate laser sensors  80 ,  84 . if scanner  146  is dropped, the user will have released his grip on the opposing buttons  172 , thereby deactivating the power to lasers  80 ,  84 , to provide some modicum of protection for them. Lasers  80 ,  84 , are more likely to be damaged if left on when dropped. 
         [0047]    In  FIG. 10 , the operation of this second embodiment of the present system is shown schematically. A vehicle  174  enters a facility where tire treads are inspected to determine if the tires are worn to the point where they should be replaced. A technician, carrying scanner  146  in his palm and already logged in, scans an image of either the license plate or the vehicle identification code of vehicle  174  by pressing button  168  of camera  142  for use in interrogating databases such as CARFAX and EXPERIAN on the internet for make, model, year and tire size of vehicle  174 . Scanner  164  then scans each tire of vehicle  174  in the order which the technician selects them. The tread depth data and vehicle information are paired and forward to a controller  178  in the facility and then sent by internet connection to cloud-based servers  182  for analysis and generation of two reports. Both reports are returned to controller  178  where one is forwarded to scanner  146  for display to the technician and the second one, a more detailed report is sent to a printer  186  where a copy is printed for the owner of vehicle  174 . The report may be sent to any part of the system anywhere in the world for storage, analysis and further action. 
         [0048]    In the foregoing embodiments, of course, scanner  18 ,  146 , may be operated with either the left or right hand and the user interface may be reversed so that the scan button can be used by those who are left-handed. Also, the display of tire condition can be done in different ways or with different colors to reflect the condition of the tires. Those skilled in tire tread depth measurement will appreciate that many other modifications and substitutions may be made to the embodiments described herein without departing from the spirit and scope of the present invention, which is defined by the appended claims.