Abstract:
Various embodiments relate to methods, systems, devices, and non-transitory media for increasing repeatability and reliability of tire testing trials including one or more of the following: capturing position data from a position sensor, wherein the capture of the position data is indicative of alignment with the desired testing area along the first axis; determining whether the position data indicates that the testing wheel is aligned with the desired testing area along a second axis that is perpendicular to the first axis, and when the position data indicates that the testing wheel is aligned with the desired testing area along a second axis, effecting initiation of a testing event.

Description:
TECHNICAL FIELD 
       [0001]    Various embodiments disclosed herein relate generally to testing apparatuses and, more particularly but not exclusively, vehicles and traction trailers for testing tire characteristics. 
       BACKGROUND 
       [0002]    Tire manufacturers frequently conduct extensive real-world testing to understand real-world characteristics of (or influenced by) new tires. For example, characteristics such as tire friction, vehicle stopping distance, blowout handling, or noise production are often best-gauged by mounting the tire to the wheel of a vehicle or trailer and gathering data at a test track. For example, one form of friction test involves mounting a tire to be tested to a wheel of a traction trailer, driving at a predetermined testing speed (e.g., 40 miles per hour), applying a brake to the wheel for a short period of time (e.g., about 1 second), and measuring various forces on the wheel during the braking period. Such data resulting from multiple trials may be compiled into a “mu-slip” curve indicative of how tire friction varies with the degree to which the tire skids along the road. More specifically, the mu-slip value indicates the amount of braking force that is generated by the tire as its rotational velocity is reduced relative to the speed of the trailer and vehicle. Such mu-slip curves provide a useful metric in comparing different tires. 
       SUMMARY 
       [0003]    A brief summary of various embodiments is presented below. Some simplifications and omissions may be made in the following summary, which is intended to highlight and introduce some aspects of the various embodiments, but not to limit the scope of the invention. Detailed descriptions of a preferred embodiment adequate to allow those of ordinary skill in the art to make and use the inventive concepts will follow in later sections. 
         [0004]    Various embodiments described herein relate to a device for facilitating tire testing, the device including: a position sensor configured to capture position data when a testing wheel is aligned with a desired testing area along a first axis; a processor in communication with the position sensor, wherein the processor is configured to: receive the position data from the position sensor when the testing wheel is aligned with the desired testing area along the first axis, determine whether the position data indicates that the testing wheel is aligned with the desired testing area along a second axis that is perpendicular to the first axis, and when the position data indicates that the testing wheel is aligned with the desired testing area along a second axis, effect initiation of a testing event. 
         [0005]    Various embodiments described herein relate to a method performed by a device for facilitating tire testing, the method including: capturing position data from a position sensor, wherein the capture of the position data is indicative of alignment with the desired testing area along the first axis; determining whether the position data indicates that the testing wheel is aligned with the desired testing area along a second axis that is perpendicular to the first axis, and when the position data indicates that the testing wheel is aligned with the desired testing area along a second axis, effecting initiation of a testing event. 
         [0006]    Various embodiments described herein relate to a non-transitory machine-readable storage medium encoded with instructions for execution by a device for facilitating tire testing, the non-transitory machine-readable storage medium including: instructions for receiving position data from a position sensor when a testing wheel is aligned with a desired testing area along a first axis, wherein the capture of the position data is indicative of alignment with the desired testing area along the first axis; determining whether the position data indicates that the testing wheel is aligned with the desired testing area along a second axis that is perpendicular to the first axis, and instructions for, when the position data indicates that the testing wheel is aligned with the desired testing area along a second axis, effecting initiation of a testing event. 
         [0007]    Various embodiments are described wherein the position sensor includes: a laser emitter positioned to impinge a laser beam upon a stationary reflective marker when the testing wheel is traveling along a track containing the desired testing area, and aligned with a desired testing area along a first axis; and a laser sensor positioned to sense the laser beam when the laser beam is reflected by the stationary reflective marker. 
         [0008]    Various embodiments are described wherein the position sensor includes a global positioning system (GPS) device. 
         [0009]    Various embodiments are described wherein the testing event is a braking event whereby brakes are applied to the testing wheel. 
         [0010]    Various embodiments are described wherein the testing event is a data capture event, whereby data is captured from at least one sensor associated with the testing wheel. 
         [0011]    Various embodiments are described wherein, in effecting initiation of a testing event, the processor is configured to transmit an instruction to a second device to initiate the testing event. 
         [0012]    Various embodiments are described wherein the second device is a controller of a traction trailer including the testing wheel. 
         [0013]    Various embodiments are described wherein the device is a vehicle further including: the testing wheel; and a braking system, wherein the second device is an on-vehicle braking actuator. 
         [0014]    Various embodiments are described wherein the second device is a pass-by noise testing system and the testing event is a recording event, whereby the pass-by noise testing system activates at least one stationary microphone. 
         [0015]    Various embodiments are described wherein, in determining whether the position data indicates that the testing wheel is aligned with the desired testing area along a second axis that is perpendicular to the first axis, the processor is configured to: determine a value range associated with the desired testing area; and determine whether the position data falls within the value range. 
         [0016]    Various embodiments are described as additionally including a memory device that stores a correlation between the value range and an identifier of the desired testing area and, in determining a value range associated with the desired testing area, the device is configured to retrieve the value range from the memory device. 
         [0017]    Various embodiments are described wherein, in determine a value range associated with the desired testing area, the processor is configured to receive, from a user, a pair of values representing the value range. 
         [0018]    Various embodiments are described as additionally including a driver display device, wherein: the position sensor is further configured to provide approach position data over a distance as the testing wheel approaches the desired testing area; and the processor is further configured to: determine whether the approach position data indicates that the testing wheel is aligned with the desired testing area along the second axis, and provide an indication to the driver via the driver display device whether the testing wheel is aligned with the desired testing area along the second axis. 
         [0019]    Various embodiments are described wherein the position sensor includes: a laser emitter positioned to impinge a laser beam upon a stationary reflective rail when the testing wheel is traveling along a track containing the desired testing area, and approaching alignment with a desired testing area along a first axis; and a laser sensor positioned to sense the laser beam when the laser beam is reflected by the stationary reflective rail. 
         [0020]    Various embodiments are described wherein the device is a vehicle to which a traction trailer including the testing wheel is capable of attachment. 
         [0021]    Various embodiments are described wherein the testing wheel is configured to travel with the position sensor. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0022]    In order to better understand various embodiments, reference is made to the accompanying drawings, wherein: 
           [0023]      FIG. 1  illustrates an example of a system for testing tire traction; 
           [0024]      FIG. 2  illustrates an example of two hardware systems configured to cooperate in performing a tire test; 
           [0025]      FIG. 3  illustrates an example of a data arrangement for storing lane definitions; 
           [0026]      FIG. 4  illustrates an example of a user interface for initiating lane calibration; 
           [0027]      FIG. 5  illustrates an example of a method for performing lane calibration; 
           [0028]      FIG. 6  illustrates an example of a user interface for initiating a tire test; 
           [0029]      FIG. 7  illustrates an example of a method for initiating a tire test dependent on appropriate tire position; and 
           [0030]      FIG. 8  illustrates an example of a method for providing driver feedback regarding tire position. 
       
    
    
       [0031]    To facilitate understanding, identical reference numerals have been used to designate elements having substantially the same or similar structure or substantially the same or similar function. 
       DETAILED DESCRIPTION 
       [0032]    The description and drawings presented herein illustrate various principles. It will be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described or shown herein, embody these principles and are included within the scope of this disclosure. As used herein, the term, “or” refers to a non-exclusive or (i.e., and/or), unless otherwise indicated (e.g., “or else” or “or in the alternative”). Additionally, the various embodiments described herein are not necessarily mutually exclusive and may be combined to produce additional embodiments that incorporate the principles described herein. 
         [0033]    Various forms of tire testing, including forms of traction testing, involve testing a tire in motion over multiple trials. In order to isolate the characteristics being tested in the resulting data, it is desirable to maintain the non-tested variables as constant as possible. When the vehicle and tire are in motion, however, it is often difficult to ensure that the test is performed at the same location each time. For example, if the driver is responsible for triggering the test on each pass, the testing location may vary by multiple feet on each pass. Further, even if multiple trials for a single tire are performed at relatively the same location on the track, it remains possible that the tests of a different tire (e.g., a reference tire) may have been performed at a different location. Due to the varying position of the test, the characteristics in the test track may vary from trial to trial (or test to test), thereby degrading the accuracy of the results or the comparability to other results. 
         [0034]    To reduce the effect of track surface variability on traction tests, it would be desirable to provide a system that is capable of performing the traction test at the same location for each trial. Similarly, for other types of tests where a tire to be tested is in motion, it would be desirable to provide a system that performs such tests at the same location for each trial. Additionally, tests similar to those described herein are often performed for the purpose of ascertaining characteristics of a road surface, rather than a tire; in some such tests it may also be desirable to ensure that the test is performed at the same location each trial. As used herein, the term “tire testing” will be understood to refer to any testing of a tire itself as well as testing of other structure&#39;s characteristics with respect to a tire in motion such as, for example, a road surface&#39;s friction properties or a sound barrier&#39;s insulation properties against tire noise. 
         [0035]    To provide such a system, various embodiments described herein utilize a position sensor, such as one or more laser emitters and sensors, to ensure that a tire to be tested is in a desired location before initiating testing. As the tire travels through or near the desired area for testing, data from the position sensor is used to determine whether the tire is indeed located within the testing area. If so, testing is initiated; otherwise, the test is not initiated and the driver may be informed that the test was not performed because the tire did not pass through the desired testing area. The driver may then attempt the test again by taking another pass. Various alternative and additional beneficial features will be described below. 
         [0036]    While various embodiments explained in detail herein are described with respect to traction testing, it will be apparent that these systems and methods may be adapted to other tests. Various modifications to enable adaptation to such other tests will be apparent. 
         [0037]      FIG. 1  illustrates an example of a system  100  for testing tire traction. As shown, a vehicle  110  (such as a truck or other automobile) tows a traction trailer  120  to which a tire  125  to be tested is mounted. The traction trailer  120  includes components configured to perform functions related to testing the tire such as a brake caliper, brake pads, and disc (not shown) for slowing the rotational velocity of the tire  125  and thereby causing the tire  125  to brake, sensors (e.g., load cells for measuring vertical load on the tire  125  and braking force generated by the tire  125 , or an encoder to measure rotational velocity of the tire) (not shown) for gathering data regarding the tire&#39;s performance while the brakes are applied, and a controller for coordinating these functions into a repeatable test. Various components and arrangements thereof for providing a traction trailer  120  for testing a tire  125  will be apparent. 
         [0038]    The vehicle  110  is driven by a human driver and tows the trailer  120  to put the tire  125  into motion for purposes of the traction test. As such, the vehicle  110  may be virtually any vehicle, such as a stock truck with a ball hitch. According to various embodiments, the vehicle  110  is also equipped with various sensors and a controller for facilitating the test performed by the traction trailer  120 , as will be described in greater detail below. 
         [0039]    It will be apparent that various alternative arrangements may be used to provide testing functionality similar to that described herein. For example, the appropriate testing systems from the traction trailer  120  may be integrated into the vehicle  110  and the tire  125  may be mounted to one of the four wheels of the vehicle. Alternatively, the tire  125  may be mounted to a third wheel on the trailer  125  or a fifth wheel loaded through the floor of the vehicle  110  (e.g., in the case of a “traction van”). As another example, the vehicle  110  may be a remote controlled or autonomous vehicle. Similarly, the traction trailer  120  may not be a trailer per se and, instead, may include an engine, motor, or other means for propulsion. In such an embodiment, the traction trailer may carry a human driver, may be remote controlled, or may be autonomously driven by the onboard controller. Various additional variations will be apparent. 
         [0040]    To facilitate testing of the tire on a wet surface, the system includes a water outlet pipe  130  and drain  135  located on opposite sides of a length of track  140 . The pipe  130  includes multiple outlets that, when water flows through the pipe  130 , the water is sprayed onto the track  140 . The water flows across the track  140  (which may be slightly inclined to facilitate water movement) and into the drain  135  for collection and potential reuse. 
         [0041]    The track is divided into multiple lanes  141 ,  142 ,  143 ,  144 ,  145 ,  146 ,  147 ,  148  for the purposes of testing. As shown, paint is applied to the track  140  to identify the boundaries between the lanes  141 - 148 . Such paint may aid the driver in positioning the tire  125  within a desired lane for testing. However, in various alternative embodiments, the track may not include any visible indication of the lanes  141 - 148  and, instead, the lanes may be defined purely digitally based on sensor data (as will be described below). Further, in some such embodiments, driver feedback may be provided by a controller of the vehicle via a driver display (as will be described below). 
         [0042]    For the purposes of defining lanes and desired testing areas, two axes may be ascribed to the track  140 . An x-axis may be defined as running along the track (e.g., from left to right in  FIG. 1 ). X-axis alignment may therefore be taken to indicate that the tire has arrived the desired position along the length of the track in its travel (though may not necessarily be aligned with the desired lane). Conversely, a y-axis may be defined as running perpendicular to the x-axis and from one side of the track to the other. Y-axis alignment may therefore be taken to indicate whether or not the tire is currently within the desired testing lane (though may not necessarily have reached the desired position along the length of the track). 
         [0043]    In some embodiments the lanes  141 - 148  are each between one and two feet wide and define (along one axis) an area that may be used for testing of a tire. As such, each lane may be provided with different surface characteristics for performing different tests. For example, lanes  141 - 144  may include patches of asphalt of varying ages, varying mix, or varying construction/design while lanes  145 - 148  may include patches of various types of concrete such that traction on various road types may be tested. Alternatively, the lanes  141 - 148  may be initially paved with roughly the same surface characteristics and may be subdivided simply for the purpose of correlating test data to the particular testing area. 
         [0044]    It will be apparent that the lanes  141 - 148  may vary in other embodiments. Some embodiments may include more or fewer lanes than those illustrated. Further, in some embodiments, the lanes may be narrower or wider than illustrated. For example, some embodiments may include a single lane that is 12 feet wide and, as such, approximates a standard lane for road driving. Further, in some embodiments, the lanes  141 - 148  may vary in width, length, surface characteristics, etc. 
         [0045]    In some embodiments, the lanes  141 - 148  demarcated by paint lines may not exactly correspond to lanes defined for the purposes of testing. For example, while the lanes  141 - 148  may be 12 feet wide, the lanes defined for testing by the controller device of the vehicle  110  or trailer  120  may be one or two feet wide and located within the lane where the tire to be tested  125  is expected to travel when the vehicle  110  is traveling within the associated physical lane  141 - 148 . As used herein, unless otherwise indicated as one or more of lanes  141 - 148  or as a “physical lane,” the term “lane” will be understood to refer to a length of track defined and recognized by a controller device of the vehicle  110  or trailer  120 . 
         [0046]    To facilitate making a determination of whether the tire  125  is properly aligned with a desired testing area prior to test initiation, the system  100  includes a position sensor  150 . As shown, the position sensor  150  is mounted to the front of the vehicle; it will be apparent, however, that the position sensor  150  may be located anywhere on or within the vehicle  110  or trailer  120  so long as the function of the position sensor  150  is not prevented by its location. 
         [0047]    In the illustrated embodiment, the position sensor includes a laser emitter and sensor  150  (shown together as a single black box). A stationary reflective marker  155  is positioned at a desired location beside the track where the laser emitter  150  will impinge upon the reflective surface  155  when the tire  125  is aligned with a desired testing area along an x-axis (but not necessarily along the y-axis). In other words, when the laser emitter  150  passes the reflective marker  155 , the laser beam is reflected back into the laser sensor, thereby indicating that the vehicle (and consequently, the tire  125 ) has reached a predefined position along the x-axis of the track  140 . As such, the reflective marker  155  is placed, prior to the test, at a location along the side of the track corresponding to the location along the x-axis of the track that includes the desired testing area. For example, the marker  155  may be placed along the x-axis at a distance from the desired testing area that is equal to the distance between the laser emitter and sensor  150  and the tire  125 . It will be apparent that various additional or alternative sensors to laser sensors may be used to serve as a position sensor such as, for example, ultrasonic sensors, other optical sensors, global positioning system (GPS) sensors, cameras, etc. Various modifications to enable such other sensor types to provide data indicative of alignment along one axis (x, y, z, etc.) that is useful to determine alignment on another axis (whether through hardware, software, or a combination thereof) will be apparent. 
         [0048]    In some embodiments, the sensor  150  may include some stationary components and some components that travel with the tire to be tested  125 . For example, because it is used in conjunction with the laser sensor  150  to perform position measurements, the reflective target  155  may be considered a stationary part of an overall sensor. As another example, in some embodiments, the positions of the laser sensor and reflective marker may be reversed, wherein the laser sensor is stationary and the reflective marker is attached to the vehicle  110  or trailer  120 ; in such an embodiment, the overall position sensor may include the laser emitter, the laser sensor, the reflective marker, and the controller interface of the vehicle  110  or trailer  120  that receives sensed data from the stationary laser sensor. In another embodiment, a different type of stationary sensor such as, for example, a camera, may be used to judge whether the tire  125  is within a desired testing area according to the methods described herein and report sensed data to a controller of the vehicle  110  or trailer  120  via a data connection. In embodiments where a stationary sensor reports sensed data to a controller traveling with the tire  125 , the controller interface that receives the sensed data may also be considered to be part of the position sensor. As such, in each of these examples, the position sensor may be said to move with the tire  125  even though some components are stationary (or otherwise do not travel with the tire  125 ). Various additional modifications will be apparent. 
         [0049]    Upon receiving position data indicative of x-axis alignment with the desired testing area (e.g., upon receiving any data from the laser sensor  150 ), the controller of the vehicle interprets the reported data to determine whether the tire  125  is also aligned with the desired testing area along the y-axis of the track (e.g., whether the tire is located within the appropriate lane). The term “position data” as used herein will be understood to refer to any information that may be used to infer, at least partially, the position of the vehicle including, as in the present example, information conveying a measured distance from the marker  155 . For example, the voltage reported by the laser sensor  150  may be proportional to (and thereby indicative of) the distance between the sensor  150  and the marker  155 . If the voltage or distance falls within a predetermined range associated with the desired lane or lateral position, the vehicle  110  controller determines that the tire  125  is also properly aligned along the y-axis of the track and initiates a testing event. For example, the controller of the vehicle  110  may transmit an instruction to the controller of the trailer  120  indicating that the braking test should be performed. If the voltage or distance falls outside the predetermined range, the controller of the vehicle  110  determines that the tire  125  is not properly aligned and refrains from initiating any testing events. In some embodiments, the controller of the vehicle  110  may also report testing failure to the driver via a driver interface so that the driver knows to reattempt the test. 
         [0050]    In various embodiments, while the marker  155  is stationary during the test, it may be movable along the x-axis of the track  140  to account for differences in position sensor placement or different vehicles  110  or trailers  120 . The marker  155  may also be movable to enable selection of alternate testing areas along the x-axis of the track. In some embodiments, different testing areas along with the x-axis of the track may be defined by deploying multiple markers  155 . For example, a first marker may be deployed at a first height and a second marker may be deployed at a second height. Thereafter, the vertical position of the laser emitter and sensor  150  may be adjusted to impinge on one such marker but not the other, thereby selecting the x-axis position associated with one of the multiple markers. As another alternative, multiple markers may be vertically-aligned with each other such that the laser sensor  150  will sense a reflection from each marker that is passed. To select a location along the track  140  x-axis for the desired testing area, a user may indicate a number of the marker to be used as the x-axis trigger by, for example, specifying the marker number or specifying a testing area which is previously correlated in memory to the marker number. Then, during the test, the processor may count the number of separate markers passed (as sensed by the laser sensor  150 ), and determine that the appropriate x-axis alignment has been reached when a number of markers equal to the specified marked number has been sensed. 
         [0051]    In some embodiments, the marker  155  is alternatively or additionally movable along the y-axis of the track  140 . For example, the marker  155  may be moved further away from the side of the track  140 . Such functionality may provide an alternative method for lane selection. In some such embodiments, instead of matching sensed position data to a range uniquely associated with a desired lane, the controller of the vehicle  110  may compare the position data to a static range defining predetermined distance(s) away from the marker. As such, moving the marker  155  closer to or further away from the side of the track  155  will have the effect of changing the selected lane on the track wherein testing events will be triggered. Alternatively, other values may be compared to the position data. For example, a single distance value may be compared to the position data and, if the difference between the two values are within an acceptable threshold, the testing events may be triggered. 
         [0052]    Another feature that the system  100  may include is y-axis alignment reporting during the approach to x-axis alignment. As shown, the system  100  includes an additional laser emitter and sensor  160  mounted to the vehicle  110 , a reflective rail  165  positioned alongside the track  140 , and a driver display (not shown) inside the vehicle. As with the primary laser emitter and sensor  150 , the additional laser emitter and sensor  160  may be mounted anywhere on the vehicle  110  or trailer  120 , may be a sensor other than a laser sensor, or may take on any of the variations described with respect to the primary laser emitter and sensor  150 . The reflective rail  165 , like the reflective marker  150 , may include any surface characteristics effective to reflect a laser beam back to the sensor  160 . As shown, the rail  165  is located at a different height from the reflective marker  155  (above or below) so that the reflective rail  165  does not reflect the laser beam of the primary sensor  150  and falsely initiate a trigger based on an incorrect determination of x-axis alignment. It will be apparent that the data sensed due to reflection off of the rail  165  may be used for purposes in addition or alternative to reporting alignment to a driver. For example, as noted above, in some alternative embodiments, the vehicle  110  or trailer  120  may be an autonomous vehicle. In some such embodiments, alignment data sensed off of the rail  165  may be used as input into the autonomous driving program. Various additional embodiments will be apparent. 
         [0053]    As the vehicle  110  and trailer  120  approaches the marker  155 , the secondary sensor  160  emits a laser beam onto the rail  165  and senses the reflected beam. From the sensed data, in a manner similar to that described with respect to the primary sensor  150 , the vehicle  110  controller determines whether the tire  125  is currently aligned along the y-axis (even though it may not yet be aligned along the x-axis) with the desired testing area. The controller also keeps the driver display updated with an indication of whether the tire  125  is currently aligned along the y-axis. For example, the display may indicate to the driver whether the tire  125  is currently aligned or whether the driver should adjust the driving path left or right to achieve alignment. In some embodiments, the display may indicate how far the driver should adjust to achieve alignment. While shown as two separate objects, in some embodiments the marker  155  and rail  165  may be a single reflective object. For example, the rail may simply include an upward projection at one end to form the marker  155  (e.g. to form the shape of an “L”). 
         [0054]    While two separate laser emitters and sensors  150 ,  160  are shown, they may together constitute a single “position sensor” system along with any additional position sensing hardware. In some alternative embodiments, approach alignment reporting may be provided without use of a secondary laser emitter and sensor  160 . Various modifications to implement such functionality will be apparent. For example, the marker  155  and rail  165  may be aligned vertically such that the laser emitter and sensor  150  may impinge upon and sense reflections from both. The marker  155  and rail  165  may be positioned with a gap between the reflective surfaces horizontally such that as the sensor  150  passes from the rail  165  to the marker  155 , there is a period of time where the sensor  150  does not pick up any reflection. As such, the controller of the vehicle may use this gap to differentiate between the rail  165  and the marker  155  for the purposes of determining x-axis alignment. As another embodiment, the marker  155  and rail  165  may be vertically aligned and not provided with any gap therebetween. Instead, the marker  155  and rail  165  may include different reflective characteristics from each other. The vehicle  110  controller may then interpret the change in characteristics (e.g., through a sudden change in sensed data) as an indication of x-axis alignment. As yet another example, the marker  155  may be omitted and the controller may interpret the sensor  150  moving past the end of the rail  165  to indicate x-axis alignment and may utilize the most-recent sensed data from the sensor  150  to determine y-axis alignment. Various additional modifications will be apparent. 
         [0055]      FIG. 2  illustrates an example of two hardware systems  200 ,  250  configured to cooperate in performing a tire test. The hardware systems  200 ,  250  may implement a vehicle system  200  and trailer system  250  as described above with respect to the testing system  100  of  FIG. 1 . As shown, the first device  200  includes a processor  210 , memory  215 , user interface  220 , network interface  225 , laser sensor(s)  230 , and storage  235  interconnected via one or more system buses  205 . Similarly, the second device  250  includes a processor  260 , memory  265 , network interface  275 , brake system  280 , sensors  285 , and storage  290  interconnected via one or more system buses  255 . It will be understood that  FIG. 2  constitutes, in some respects, an abstraction and that the actual organization of the components of the devices  200 ,  250  may be more complex than illustrated. 
         [0056]    The processors  210 ,  260  may each be any hardware device capable of executing instructions stored in the respective memories  215 ,  265  or storages  235 ,  290  or otherwise processing data. As such, the processors  210 ,  260  may include a microprocessor, field programmable gate array (FPGA), application-specific integrated circuit (ASIC), programmable logic controller (PLC), or other similar devices. 
         [0057]    The memories  215 ,  265  may each include various memories such as, for example L1, L2, or L3 cache or system memory. As such, the memories  215 ,  265  may include static random access memory (SRAM), dynamic RAM (DRAM), flash memory, read only memory (ROM), or other similar memory devices. 
         [0058]    The user interface  220  may include one or more devices for enabling communication with a user. For example, the user interface  220  may include a display, a touchscreen, a mouse, and a keyboard for receiving user commands. In some embodiments, the user interface  220  may include a command line interface or graphical user interface that may be presented to a remote terminal via the network interface  225 . 
         [0059]    The laser sensor(s)  230  may include one or more devices capable of sensing a laser beam and outputting a voltage or other value indicative of a distance to the system bus  205 . For example, the laser sensor(s)  230  may correspond to the sensors  150 ,  160  described with respect to  FIG. 1 . As noted, in some embodiments, the laser sensor(s)  230  may be mounted to the trailer instead of the towing vehicle  110 ; in some such embodiments, the laser sensor(s)  230  may additionally or alternatively attach to the system bus  255  of the trailer system  250 . 
         [0060]    The brake system  280  may include a controllable system for applying brakes to a testing wheel (and consequently, to the tire to be tested attached to the testing wheel). For example, the braking system may be one or more caliper brakes of the trailer capable of being controlled to brake via the system bus  255 . In other embodiments, such as embodiments wherein the two devices  200 ,  250  are combined into a single vehicle system for on-vehicle tire testing, the brake system  280  may be the stock anti-lock brake system (ABS) of the vehicle controllable via the system bus. 
         [0061]    The sensors  285  include one or more sensors for gathering data related to a tire test. For example, the sensors  285  may include one or more force sensors for determining vertical, horizontal, and rotational forces applied to the testing wheel. As an additional or alternative example, the sensors  285  may include one or more optosensors configured to track rotation speed of the testing wheel. Various additional sensors useful in performing a tire test will be apparent. 
         [0062]    The network interfaces  225 ,  275  may each include one or more devices for enabling communication with other hardware devices. For example, the network interfaces  225 ,  275  may include a network interface card (NIC) configured to communicate according to the Ethernet protocol or WiFi protocol. Additionally, the network interfaces  225 ,  275  may implement a TCP/IP stack for communication according to the TCP/IP protocols. Various alternative or additional hardware or configurations for the network interfaces  225 ,  275  will be apparent. As shown, the network interfaces  225 ,  275  are configured to communicate with each other via, for example, a WiFi or Ethernet connection. 
         [0063]    The storages  235 ,  290  may each include one or more machine-readable storage media such as read-only memory (ROM), random-access memory (RAM), magnetic disk storage media, optical storage media, flash-memory devices, or similar storage media. In various embodiments, the storages  235 ,  290  may store instructions for execution by the respective processors  210 ,  260  or data upon with the respective processors  210 ,  260  may operate. 
         [0064]    The storage  235  of the vehicle system  200  may include various instructions for achieving the functionality described herein. For example, the storage  235  may include laser sensor calibration instructions  236  for determining thresholds associated with various lanes, for future use in determining y-axis alignment. Such calibrated thresholds  237  may also be stored in the storage  235 . Prior to beginning a test, lane selection instruction  238  may be used to allow a user (e.g., the driver) to select a lane within which to perform the test. Then, during test performance, trigger monitoring instructions  239  may monitor the laser sensor  230  output to determine when the tire to be tested is aligned with the desired testing area along the x- and y-axes. When the tire is properly aligned, braking event initiation instructions  240  transmit a braking event to the trailer system  250  via the network interface  225  to begin the tire test. Additionally, distance monitoring instructions  241  may monitor the sensors  230  during approach to determine if the testing wheel is aligned on the y-axis and driver feedback instructions  242  for giving the driver an indication of alignment or mis-alignment. In some embodiments, the vehicle  200  may further participate in the testing process after sending a braking event and, in such embodiments, the storage  235  also includes further testing instructions  243  for implementing such functionality. 
         [0065]    The storage  290  is shown to include event handling instructions  291  for receiving and interpreting events, such as braking events, received from the vehicle system  230  via the network interface  275 . Brake system control instructions  292  control the brake system  280  during a test to apply brakes to the testing wheel (e.g., apply brakes for an appropriate period of time). Data gathering instructions  293  gather data from the sensors  285  while the brakes are applied and the report generation instructions  294  interpret the data to calculate figures that are human readable (e.g., mu slip curves). 
         [0066]    Various modifications to the two systems  200 ,  250  will be apparent. For example, where the laser sensor  230  is in communication with the trailer system bus  255 , the trailer storage  290  may include the instructions and data  236 - 241 , which will communicate with the driver feedback instructions  242 . As another example, the report generation instructions  294  may be omitted and another system (not shown) may be used to interpret the gathered data. As yet another example, where the tire to be tested is mounted to the vehicle itself, the trailer system  250  may be omitted, and the instructions  291 - 294  may be stored on the storage  235 . 
         [0067]    It will be apparent that various information described as stored in the storages  235 ,  290  may be additionally or alternatively stored in the memories  215 ,  265 . In this respect, the memories  215 ,  265  may also be considered to constitute “storage devices” and the storages  235 ,  290  may be considered “memories.” Various other arrangements will be apparent. Further, the memories  215 ,  265  and storages  235 ,  290  may both be considered to be “non-transitory machine-readable media.” As used herein, the term “non-transitory” will be understood to exclude transitory signals but to include all forms of storage, including both volatile and non-volatile memories. 
         [0068]    While the devices  200 ,  250  are shown as including one of each described component, the various components may be duplicated in various embodiments. For example, the processor  210  may include multiple microprocessors that are configured to independently execute the methods described herein or are configured to perform steps or subroutines of the methods described herein such that the multiple processors cooperate to achieve the functionality described herein. 
         [0069]      FIG. 3  illustrates an example of a data arrangement  300  for storing lane definitions. The data arrangement  300  may correspond to the lane thresholds  237  of  FIG. 2 . As shown, the data arrangement  300  correlates a lane identifier field  305  with a minimum voltage field  310  and a maximum voltage field  315 . In other words, each record of the data arrangement  300  specifies for each lane, a range of sensor voltages defining the bounds of the lane. As an example, a first record  320  indicates that a lane identified as “A” exists between the y-axis positions that yield sensor outputs between 1.25-2.1 volts. Similarly, record  330  indicates that lane “B” is correlated to voltage range 2.5-3.35, and record  340  indicates that lane “C” is correlated to voltage range 3.9-4.75. As explained, these values may be used to determine, based on a voltage received from a laser sensor, whether the testing wheel is currently aligned with the desired testing area. 
         [0070]      FIG. 4  illustrates an example of a user interface  400  for initiating lane calibration. The user interface may be displayed as part of the laser sensor calibration instructions  326  of  FIG. 2 . The user interface  400  may be used for a user to indicate which lane is to be calibrated. For example various methods may enable lane calibration while the vehicle and trailer are stationary. According to some such embodiments, the vehicle and trailer may be stopped at a desired distance from the marker and calibration may be initiated to read the current distance to the marker from the laser sensor. This measured distance may then be saved for later use during tire testing. Other methods may calibrate the lane values while the vehicle is in motion and, as such, the interface  400  may indicate which lane is to be calibrated in the upcoming pass. As such, the interface includes input controls for indicating whether an existing lane should be recalibrated  410  or whether a new lane should be created and calibrated  420 . When the recalibrate option  410  is selected, a drop down selection  415  enables the user to indicate which existing lane should be recalibrated. For example, based on the example records of  FIG. 3 , the box  415  may provide as options “A” “B” and “C.” the new lane option  420  is selected, a text entry control  425  enables a user to enter a name for the new lane. Another text field  430  allows the user to indicate how wide the new lane will be. As will be seen, this value may be used to compute the voltage/distance range within which the lane exists. In some embodiments, the lane width may be statically implemented and the text field  430  may be omitted. Finally, a begin button  440  is provided to initiate the calibration test. 
         [0071]    It will be apparent that various additional fields may be provided to configure the calibration procedure. For example, in embodiments enabling multiple positions for x-axis alignment (e.g., multiple markers or distance tracking along the alignment rail), there may be provided an input control for selecting the x-axis location for calibration. As another example, in some embodiments, the user may be able to manually calibrate a lane without performing a pass and, instead, directly inputting (or modifying previously calibrated values) voltage or distance values to be correlated to the lane label. 
         [0072]      FIG. 5  illustrates an example of a method  500  for performing lane calibration. The method  500  may correspond to the laser sensor calibration instructions  326  of  FIG. 2 . The method  500  begins in step  505  after the user requests a lane calibration by, for example, selecting the begin button  440  of the user interface  400 . In step  510 , the device receives a lane identification and lane width such as, for example, the values input into the user interface  400 . The device then waits, in step  515 , to receive voltage from the laser sensor. During this time, the driver is expected to drive past a reflective marker within the desired lane to cause the laser sensor to output a voltage. Various modifications useful to support the various embodiments wherein the sensor may also output voltages based off an alignment rail or non-selected markers will be apparent (e.g., waiting for a gap in voltage or counting markers until the selected marker is encountered). 
         [0073]    After receiving voltage data indicative of x-axis alignment, the device begins to derive a voltage range by, in step  520 , calculating a voltage margin using the provided lane width. For example, based on known characteristics of the laser sensor, the device may determine what difference in voltage would be expected across the provided lane width. In some embodiments, such as those using sensors that do not have a constant correlation between distance and voltage change at all distances, this calculation may also take into account the actual sensed voltage. In other embodiments, no calculation may be necessary and, instead, the user may have input the voltage margin itself via the interface  400  instead of a lane width. In step  525 , the device creates the voltage range with the sensed data at the center by adding and subtracting half of the margin width. For example, if the sensor provided a measured voltage of 1.675V and the margin was computed as 0.85V, the device may produce a range of 1.25-2.1V in step  525 . Various alternative methods for computing a voltage range for use in determining y-axis alignment will be apparent. Finally, the device correlates the range to the lane identifier for future use in step  530 . For example, the device may modify or create a record in the data structure  300 , as appropriate. The method  500  then proceeds to end in step  535 . 
         [0074]    It will be appreciated that various alternative lane calibration methods may be used. For example, rather than adding a margin to a single measurement, some methods may utilize multiple measurements. In some such embodiments two or more such stationary measurements may be taken to define a testing lane. For example, the vehicle and trailer may first be stopped at the desired left-most position of the lane for a first reading, and then stopped at the desired right-most position of the lane for a second reading. These two readings may then be stored as a distance range defining the extents of the newly-calibrated lane. Various modifications to the methods described herein to achieve such functionality will be apparent. 
         [0075]      FIG. 6  illustrates an example of a user interface  600  for initiating a tire test. This interface  600  may be provided as part of the lane selection instructions  238  of  FIG. 2 . As shown, the interface  600  provides three options  610 ,  620 ,  630  for specifying a lane in which to perform a tire test. A first option  610  allows a user to identify a pre-calibrated lane through use of a drop down selection  615 . A second option  620  provides two text boxes  623 ,  627  where the user may manually enter distances from the sensor to be used in triggering the test. In a manner similar to that described above, the device may then calculate the appropriate voltage range using the known characteristics of the laser sensor, laser emitter, laser reflector, etc. As a third option  630 , the user may also enter the voltages themselves in two provided text fields  633 ,  637 . The user may then select the begin button  640  to initiate the test. 
         [0076]    It will be apparent that various additional fields may be provided to configure the calibration procedure. For example, in embodiments enabling multiple positions for x-axis alignment (e.g., multiple markers or distance tracking along the alignment rail), there may be provided an input control for selecting the x-axis location for calibration. 
         [0077]      FIG. 7  illustrates an example of a method  700  for initiating a tire test dependent on appropriate tire position. The method  700  may correspond to the trigger monitoring instructions  239  and braking event initiation instructions  240  of  FIG. 2 . The method begins in step  705  after the user requests performance of a test by, for example, selecting the button  640  of user interface  600 . Then, in step  710 , the device receives an identification of a lane to be tested such as, for example, values inputted by the user into the interface  600 . Then, in step  715 , the device determines the voltage range correlated with the identified lane by, for example, referring to the data arrangement  300  of  FIG. 3 . It will be apparent that various alternative steps to step  710 ,  715  may be used to determine the voltage range. For example, where the user provides the voltages manually or provides the range in feet or other distance unit, these steps may be omitted or replaced with appropriate steps for deriving the voltage range. Alternatively, in various embodiments, sensed data will be first converted into a distance and then compared to a distance range instead of a voltage range. Various modifications to each of the methods and systems herein to provide such an alternative comparison will be apparent. 
         [0078]    After determining the voltage range, the device waits to receive a voltage from the laser sensor in step  720 .During this time, the driver is expected to drive past a reflective marker within the desired lane to cause the laser sensor to output a voltage. Various modifications useful to support the various embodiments wherein the sensor may also output voltages based off an alignment rail or non-selected markers will be apparent (e.g., waiting for a gap in voltage or counting markers until the selected marker is encountered). 
         [0079]    After receiving voltage data indicative of x-axis alignment, the device determines, in step  725  whether the sensed voltage falls within the voltage range for the selected lane. If so, the device determines that the testing wheel and tire are aligned with the desired testing area along both the x- and y-axes and transmits a braking event (or other testing event) to the trailer controller in step  730 . In response to receiving the braking event, the traction trailer initiates the test. If, however, the voltage is determined to fall outside of the voltage range, the device refrains from sending a testing event and, instead, indicates in step  735  that the test was not performed and that the driver should attempt to drive past the marker again. The method  700  then proceeds to end in step  740 . Alternatively, the method may loop from step  735  back to step  720  to allow the drive to continue trying until the test is initiated. 
         [0080]      FIG. 8  illustrates an example of a method  800  for providing driver feedback regarding tire position. The method  800  may correspond to the distance monitoring instructions  241  and driver feedback instructions  242  of  FIG. 2 .The method begins in step  805  after the user requests performance of a test by, for example, selecting the button  640  of user interface  600 . Accordingly, the method  800  may run parallel to the method for initiating the test  700  as, for example, a separate thread on the same processor. Alternatively, the two methods  700 ,  800  may begin as a single thread and include some steps (e.g., steps  810 ,  815 ) in common and subsequently fork into two or more threads. Various alternative implementations will be apparent. 
         [0081]    In step  810 , the device receives an identification of a lane to be tested such as, for example, values input by the user into the interface  600 . Then, in step  815 , the device determines the voltage range correlated with the identified lane by, for example, referring to the data arrangement  300  of  FIG. 3 . It will be apparent that various alternative steps to step  810 ,  815  may be used to determine the voltage range. For example, where the user provides the voltages manually or provides the range in feet or other distance unit, these steps may be omitted or replaced with appropriate steps for deriving the voltage range. Alternatively, in various embodiments, sensed data will be first converted into a distance and then compared to a distance range instead of a voltage range. Various modifications to each of the methods and systems herein to provide such an alternative comparison will be apparent. 
         [0082]    In step  820 , the device receives a voltage from the secondary laser sensor (e.g., laser sensor  160  of  FIG. 1 ). It will be apparent that, in embodiments where a separate sensor is not provided for approach alignment tracking, the step  820  may instead receive a voltage (or other value) from the primary sensor. In step  825 , the device determines whether the sensed voltage falls within the range determined in step  815 . If so, the device determines that the testing wheel is currently properly aligned on the y-axis and indicates this fact to the driver in step  830 . Otherwise, the device indicates, in step  835 , that the testing wheel is not currently aligned and, as such, the test will fail unless the alignment is corrected. Step  835  may include providing additional information such as, for example, which direction the driver should correct to achieve y-axis alignment or the wheel&#39;s current distance away from y-axis alignment. 
         [0083]    After providing the appropriate indication to the driver in step  830  or  835 , the device determines whether the test has ended  840 . For example, if the method  700  has previously issued a braking event, the device may determine that the testing is over and position tracking no longer need be performed. If so, the method may proceed to end in step  845 . Otherwise, if the test is ongoing, the method  800  may loop back to step  820  to continue monitoring y-axis alignment. 
         [0084]    Various additional modifications to the systems and methods described herein will be apparent. For example, in some embodiments, method  700 ,  800  may be modified to gather data for multiple trials in one execution. The user interface  600  may be modified to enable the user to specify a number of trials to be performed and the method  700 ,  800  may be modified to count the number of successful tests and not proceed to end until the input number of trials have been reached. Additionally, some embodiments may include support for conducting trials each trial in opposite directions such that the driver may pass the marker or rail in either direction, thereby potentially speeding up the process of gathering multiple trials. Various modifications for enabling the system to determine the current direction of the vehicle, to sense the reflective marker regardless of which side of the track it is located (from the perspective of the vehicle), and then to make adjustments for the alternate position of the tire with respect to the sensor when traveling in the opposite direction (e.g., sensor mounted above the testing wheel, additional markers, or tracking a distance traveled from the marker before determining x-axis alignment) will be apparent. 
         [0085]    As noted above, it will also be apparent that the systems and methods described herein may be adaptable to virtually any test that is in motion but where proper positioning is important or otherwise useful. For example, in a stopping distance test, a controllable brake actuator may be installed in the vehicle itself and the tire to be tested may be mounted on one or more of the vehicle wheels. In such tests, the systems described herein to determine x- and y-axis alignment may be used to initiate a braking event that controls the brake actuator to engage the ABS system for purposes of the test. 
         [0086]    The methods herein may also be used to determine when to initiate testing events other than brake events. For example, a hydroplaning test may involve driving a vehicle at a predetermine speed across wet track and gathering data without applying brakes. The systems described herein may be used to initiate a data gathering event when the vehicle is within a desired testing area while driving over the wet track. Another test is a pass-by noise test in which stationary microphones are positioned beside the track to record noise from the tires as the vehicle passes at a predetermined speed. The methods described herein may be used to transmit a record event to the microphone system when the vehicle is at the desired location. The record event, for example, may be interpreted by the microphone system as an instruction to activate the microphones and begin recording or otherwise processing audio data retrieved therefrom. Another form of test is a blowout test wherein the tire is driven over a blade positioned on the track. The systems used herein may be used to help the driver ensure that the tire to be tested is properly positioned to hit the blade and potentially cause a blowout. Various additional testing contexts for the systems and methods described herein will be apparent. 
         [0087]    According to the foregoing, various embodiments provide greater confidence that tire testing is performed in a controlled and repeatable fashion. For example, by providing position sensors on the testing vehicle or other apparatus, a controller can refrain from performing testing when the driver was unable to position the tire to be tested sufficiently close to the area of track where previous testing has occurred or where testing is otherwise desired to occur. Various additional benefits will be apparent in view of the foregoing. 
         [0088]    It should be apparent from the foregoing description that various embodiments of the invention may be implemented in hardware. Furthermore, various embodiments may be implemented as instructions stored on a non-transitory machine-readable storage medium, such as a volatile or non-volatile memory, which may be read and executed by at least one processor to perform the operations described in detail herein. A machine-readable storage medium may include any mechanism for storing information in a form readable by a machine, such as a personal or laptop computer, a server, or other computing device. Thus, a non-transitory machine-readable storage medium excludes transitory signals but may include both volatile and non-volatile memories, including but not limited to read-only memory (ROM), random-access memory (RAM), magnetic disk storage media, optical storage media, flash-memory devices, and similar storage media. 
         [0089]    It should be appreciated by those skilled in the art that any block diagrams herein represent conceptual views of illustrative circuitry embodying the principles of the invention. Similarly, it will be appreciated that any flow charts, flow diagrams, state transition diagrams, pseudo code, and the like represent various processes which may be substantially represented in machine readable media and so executed by a computer or processor, whether or not such computer or processor is explicitly shown. 
         [0090]    Although the various embodiments have been described in detail with particular reference to certain aspects thereof, it should be understood that the invention is capable of other embodiments and its details are capable of modifications in various obvious respects. As is readily apparent to those skilled in the art, variations and modifications can be effected while remaining within the spirit and scope of the invention. Accordingly, the foregoing disclosure, description, and figures are for illustrative purposes only and do not in any way limit the invention, which is defined only by the claims.