System and method for temperature compensation of drive-by reader pressure measurements

Abstract

A system compensates a drive-by reader tire pressure measurement. The system includes a drive-by reader including a sensor array. A pressure indication is determined by the drive-by reader for each tire in a set of tires. A recommended cold pressure for the tire is provided. An adjusted recommended tire pressure is determined from the pressure indication and the recommended cold pressure and accounts for the effect of temperature on the tire. An adjusted low pressure threshold is set at a predetermined level below the adjusted recommended pressure. A notification is generated by the drive-by reader for each tire, the notification including an adjusted recommended pressure that is below the adjusted low pressure threshold.

Description

Technical Field

[0001] The present invention relates generally to tire monitoring. More specifically, the present invention relates to systems and methods for monitoring the air pressure inside a vehicle tire as the vehicle drives past a reader or station. In particular, the present invention relates to a drive-by reader system that accounts for high temperature effects on tire pressure due to vehicle operation. Background Art

[0002] Multiple pneumatic tires support the vehicle and are designed to operate for relatively long periods of time. However, even long-lived pneumatic tires can experience loss of air pressure due to punctures by nails and other sharp objects, temperature changes, and / or diffusion of air through the tire itself.

[0003] Pneumatic tires may repeatedly become under-inflated because air diffusion reduces tire pressure over time. As a result, a vehicle operator or fleet operator must sequentially repeat actions to maintain the recommended air pressure in the vehicle tires to avoid reducing fuel economy, tire life, and / or vehicle braking and handling performance. To help maintain the recommended tire pressure, various types of systems that monitor the air pressure inside the tire have been developed.

[0004] One method of monitoring and / or measuring tire pressure is to measure the pressure of a tire mounted on a vehicle as the vehicle drives through a station and the tire passes a sensor mounted in the station, such a sensor being known in the art as a drive-by reader. As the tire drives onto the drive-by reader, the reader measures the inflation pressure within the tire. For example, a load sensor array may be provided in a drive-by reader that measures the force applied by the tire.

[0005] Tire pressure is determined from the measured force and may be combined with tire information and / or vehicle information. Advantages of using a drive-by reader to determine tire pressure include positioning the tire on the reader contact surface in a short time interval, which enables pressure to be determined without intrusion or entry into the tire cavity.

[0006] As with any measurement technology, the accuracy and repeatability of pressure determination by a drive-by reader are important considerations. For example, the determination of tire pressure by a drive-by reader may be affected by tire temperature. With respect to tire temperature, most drive-by readers are not capable of detecting tire temperature. However, vehicle operation often increases tire temperature, which generally increases tire pressure. As an example, a temperature increase of ten (10) degrees Fahrenheit may increase the pressure in the tire by approximately one pound per square inch (PSI).

[0007] Therefore, when measuring tire pressure via a drive-by reader after the vehicle has been in operation for an extended period of time, the pressure reading may reflect increased pressure due to increased tire temperature. The low pressure threshold of a drive-by reader is typically based on the recommended inflation pressure for the tire, i.e., the recommended cold pressure (RCP). Because the measured pressure may be artificially high due to temperature, a tire having an inflation pressure below the low pressure threshold using the recommended cold pressure may be undesirably designated as having an acceptable pressure level.

[0008] Therefore, there is a need in the art for a system and method for a drive-through reader that accounts for the effects of high temperatures on tires due to vehicle operation. Summary of the invention

[0009] According to one aspect of an exemplary embodiment of the present invention, a system for compensating drive-by reader tire pressure measurements is provided. The system includes a drive-by reader including a sensor array. A pressure indication is determined by the drive-by reader for each tire in a set of tires. A recommended cold pressure for the tire is provided. An adjusted tire recommended pressure is determined from the pressure indication and the recommended cold pressure and accounts for the effect of temperature on the tire. An adjusted low pressure threshold is set at a predetermined level below the adjusted recommended pressure. A notification is generated by the drive-by reader for each tire including an adjusted recommended pressure below the adjusted low pressure threshold.

[0010] According to another aspect of an exemplary embodiment of the present invention, a method for compensating a drive-by reader tire pressure measurement is provided. The method includes the steps of providing a drive-by reader, the drive-by reader including a sensor array. A pressure indication for each tire in a set of tires is determined using the drive-by reader, and a recommended cold pressure for the tire is provided. An adjusted recommended tire pressure is determined from the pressure indication and the recommended cold pressure, and accounts for the effect of temperature on the tire. An adjusted low pressure threshold is set at a predetermined level below the adjusted recommended pressure, and a notification is generated for each tire using the drive-by reader including an adjusted recommended pressure below the adjusted low pressure threshold.

[0011] The present invention provides the following technical solutions:

[0012] 1. A system for compensating drive-by reader tire pressure measurements, the system comprising:

[0013] driving past a reader, including a sensor array;

[0014] an indication of pressure determined by the drive-by reader for each tire in a set of tires;

[0015] Recommended cold pressure for tires;

[0016] an adjusted recommended pressure for the tire, the adjusted recommended pressure being determined by the pressure indication and the recommended cold pressure, the adjusted recommended pressure accounting for an effect of temperature on the tire;

[0017] The adjusted low pressure threshold is set at a predetermined level below the adjusted recommended pressure; and

[0018] A notification is generated by the drive-by reader for each tire, the notification including an adjusted recommended pressure that is below the adjusted low-pressure threshold.

[0019] 2. The system for compensating drive-by reader tire pressure measurements of claim 1 wherein said adjusted recommended pressure includes an assessment of a tendency of said pressure indication to be above or below said recommended cold pressure.

[0020] 3. The system for compensating drive-by reader tire pressure measurements of claim 2, wherein said adjusted recommended pressure comprises an average of said pressure indications that follow said trend.

[0021] 4. The system for compensating drive-by reader tire pressure measurements of claim 3, wherein the adjusted recommended pressure includes ignoring at least one of an extremely high pressure indication and an extremely low pressure indication.

[0022] 5. The system for compensating drive-by reader tire pressure measurements of claim 2, wherein said adjusted recommended pressure comprises an arithmetic mean of said pressure indications that follow said trend.

[0023] 6. The system for compensating drive-by reader tire pressure measurements of claim 1 wherein the adjusted recommended pressure comprises a conversion of a pressure differential to a temperature factor.

[0024] 7. The system for compensating drive-by reader tire pressure measurements of claim 1, wherein the adjusted low pressure threshold is approximately fifteen pounds per square inch lower than the adjusted recommended pressure.

[0025] 8. The system for compensating drive-by reader tire pressure measurements of claim 1 wherein the tire set includes tires on the same axle.

[0026] 9. The system for compensating drive-by reader tire pressure measurements of claim 1 wherein the set of tires includes all tires on the vehicle.

[0027] 10. The system for compensating drive-by reader tire pressure measurements according to claim 1, wherein the notification is sent to a receiving device, the receiving device comprising at least one of a computer with a display terminal, a user device, and a fleet management server.

[0028] 11. The system for compensating drive-by reader tire pressure measurements of claim 1 wherein the system determines the adjusted recommended pressure without intruding into a cavity of each tire.

[0029] 12. The system for compensating drive-by reader tire pressure measurements of claim 1, wherein the system determines the adjusted recommended pressure without a temperature sensor.

[0030] 13. A method for compensating drive-by reader tire pressure measurements, the method comprising the steps of:

[0031] providing a drive-by reader, the drive-by reader comprising a sensor array;

[0032] determining a pressure indication for each tire in a set of tires using the drive-by reader;

[0033] providing a recommended cold pressure for the tire;

[0034] determining an adjusted recommended pressure for the tire from the pressure indication and the recommended cold pressure, the adjusted recommended pressure accounting for the effect of temperature on the tire;

[0035] setting the adjusted low pressure threshold at a predetermined level below the adjusted recommended pressure; and

[0036] A notification is generated for each tire using the drive-by reader, the notification including an adjusted recommended pressure that is below the adjusted low-pressure threshold.

[0037] 14. The method for compensating drive-by reader tire pressure measurements of claim 13, wherein the step of determining an adjusted recommended pressure comprises evaluating a tendency of the pressure indication to be above or below the recommended cold pressure.

[0038] 15. The method for compensating drive-by reader tire pressure measurements of claim 14, wherein the step of determining an adjusted recommended pressure comprises averaging the pressure indications that follow the trend.

[0039] 16. The method for compensating drive-by reader tire pressure measurements of claim 15, wherein the step of determining an adjusted recommended pressure includes ignoring at least one of an extremely high pressure indication and an extremely low pressure indication.

[0040] 17. The method for compensating drive-by reader tire pressure measurements of claim 14, wherein the step of determining an adjusted recommended pressure comprises calculating an arithmetic mean of the pressure indications that follow the trend.

[0041] 18. The method for compensating drive-by reader tire pressure measurements of claim 13, wherein the step of determining an adjusted recommended pressure comprises converting the pressure differential to a temperature factor.

[0042] 19. The method for compensating drive-by reader tire pressure measurements of claim 13, wherein the set of tires includes all of the snaking tires on the vehicle.

[0043] 20. The method for compensating drive-by reader tire pressure measurements according to claim 13, further comprising the step of sending the notification to a receiving device, the receiving device comprising at least one of a computer with a display terminal, a user device, and a fleet management server. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The present invention will now be described by way of example with reference to the accompanying drawings, in which:

[0045] Figure 1 is a schematic perspective view of an exemplary embodiment of a system for compensating drive-by reader tire pressure measurements of the present invention, wherein a drive-by reader is shown mounted in the ground and a vehicle approaches the system;

[0046] Figure 2 yes Figure 1 A schematic perspective view of a system for compensating drive-by reader tire pressure measurements of the present invention is shown;

[0047] Figure 3 yes Figure 1 a schematic diagram of a load sensor array of the illustrated system;

[0048] Figure 4A yes Figure 1 A schematic diagram of a first aspect of a system for compensating drive-by reader tire pressure measurements of the present invention is shown;

[0049] Figure 4B yes Figure 1 A schematic diagram of a second aspect of a system for compensating drive-by reader tire pressure measurements of the present invention is shown;

[0050] Figure 4C yes Figure 1 A schematic diagram of a third aspect of a system for compensating drive-by reader tire pressure measurements of the present invention is shown; and

[0051] Figure 5 yes Figure 1A schematic diagram of the notification portion of the system for compensating drive-by reader tire pressure measurements of the present invention is shown.

[0052] Like reference numerals refer to like parts throughout the drawings.

[0053] definition

[0054] "Axial" and "axially" refer to lines or directions parallel to the tire's axis of rotation.

[0055] "Circumferential" refers to lines or directions extending along the perimeter of the surface of the annular tread perpendicular to the axial direction.

[0056] “Equatorial Centerplane (CP)” means the plane perpendicular to the tire's axis of rotation and passing through the center of the tread.

[0057] "Footprint" refers to the contact patch or area created by the tire tread with a flat surface as the tire rotates or rolls.

[0058] “Inboard side” means the side of the tire closest to the vehicle when the tire is mounted on the wheel and the wheel is mounted on the vehicle.

[0059] "Transverse" refers to the axial direction.

[0060] “Lateral Edge” means a line tangent to the axially outermost tread contact patch or footprint of the tire measured under normal load and inflation, the line being parallel to the equatorial centerplane.

[0061] “Net contact patch” means the total area of ​​contacting tread elements between the lateral edges around the entire circumference of the tire tread divided by the total area of ​​the entire tread between the lateral edges.

[0062] “Outer side” means the side of the tire farthest from the vehicle when the tire is mounted on the wheel and the wheel is mounted on the vehicle.

[0063] "Radial" and "radially" refer to directions radially toward or away from the axis of rotation of the tire.

[0064] "Rib" means a circumferentially extending strip of rubber on the tread, defined by at least one circumferential groove and either a second such groove or a lateral edge, the strip being undivided in the transverse direction by grooves of great depth.

[0065] "Tread element" or "traction element" means a rib or block-like element defined by a shape having adjacent grooves.

[0066] “Tread Arc Width” means the arc length of the tire tread measured between the lateral edges of the tread. DETAILED DESCRIPTION

[0067] refer to Figures 1 to 5 An exemplary embodiment of a system for compensating drive-by reader tire pressure measurements of the present invention is shown at 10. Figure 1 As shown, the system 10 evaluates the pressure of each tire 12 supporting the vehicle 14. It should be understood that the vehicle 14 can be any type of vehicle and is shown as a commercial vehicle as an example. In addition, the vehicle 14 can include any number of tires 12, and the system 10 can evaluate the pressure in any number of tires on the vehicle.

[0068] The tires 12 are of conventional construction, and as known to those skilled in the art, each tire is mounted on a respective wheel 16. Each tire 12 includes a pair of sidewalls 18 extending to a circumferential tread 20. As each tire 12 rolls over ground 24, a footprint 22 is created, which is the contact area of ​​tread 20 with the ground.

[0069] Additional references Figure 2 and 3 , system 10 includes a drive-by reader 26 mounted in or on ground 24. Drive-by reader 26 includes a housing 28 and at least one sensor 30 mounted in the housing. Preferably, an array of load sensors 30 is mounted in housing 28. The driver of vehicle 14 guides the vehicle over drive-by reader 26, which causes each tire 12 to roll over the reader. When tire 12 is positioned over sensor array 30, the array measures the force applied by the tire.

[0070] The pressure of the tire 12 is determined by the force measured by the sensor array 30 and may be combined with tire information and / or vehicle information. An exemplary technique for determining the pressure of the tire 12 is described in U.S. Pat. No. 7,942,048, which is owned by the assignee of the present application, The Goodyear Tire & Rubber Company, and is incorporated herein by reference. By using a drive-through reader 26, the pressure of the tire 12 is determined without intruding or entering the tire cavity. The drive-through reader 26 includes a processor or is in electronic communication with a processor to determine the pressure of the tire 12 from the sensor array 30.

[0071] refer to FIG. 4A to FIG. 4C As an example, a vehicle 14 may include two front tires 12A and 12B, each mounted on a front axle 34A, and eight additional tires mounted in a dual tire configuration on front and rear tandem (longitudinal) axles 34B and 34C. The front tandem axle 34B includes two tires 12C and 12D on the left side of the axle, and two tires 12E and 12F on the right side of the axle. The rear tandem axle 34C includes two tires 12G and 12H on the left side of the axle and two tires 12I and 12J on the right side of the axle. Each of the tires 12 has a recommended cold pressure (RCP) 38 and a low pressure threshold 40. In this example, as Figure 4AAs shown, each tire 12 includes a target recommended cold pressure 38 of 100 PSI, and a low pressure threshold 40 having a value of 15 PSI below the recommended cold pressure, ie, 85 PSI.

[0072] As mentioned above, and as Figure 4B As shown, the drive-by reader 26 determines a pressure indication 36 for each tire 12 on the vehicle 14. In this example, for the front axle 34A, the drive-by reader 26 provides a first pressure indication 36A of 120 PSI for the left tire 12A, and a second pressure indication 36B of 90 PSI for the right tire 12B. For the front tandem axle 34B, a third pressure indication 36C of 130 PSI is provided for tire 12C, a fourth pressure indication 36D of 140 PSI is provided for tire 12D, a fifth pressure indication 36E of 100 PSI is provided for tire 12E, and a sixth pressure indication 36F of 90 PSI is provided for tire 12F. For rear tandem axle 34C, a seventh pressure indication 36G of 100 PSI is provided for tire 12G, an eighth pressure indication 36H of 115 PSI is provided for tire 12H, a ninth pressure indication 36I of 130 PSI is provided for tire 12I, and a tenth pressure indication 36J of 125 PSI is provided for tire 12J.

[0073] Figure 4B The pressure indication 36 in is based on cold pressure and is not compensated for temperature, so all tires 12 are indicated as having acceptable pressures. However, the pressure indication 36 may be artificially high due to temperature, resulting in tires with inflation pressures below the low pressure threshold 40 being indicated as acceptable.

[0074] Special References Figure 4B and Figure 4C , the system 10 compensates for temperature by converting the pressure indication 36 based on the recommended cold pressure 38 to an adjusted recommended pressure (ARP) 42 that accounts for the temperature. More specifically, a group 46 of tires 12 is selected for comparison. It should be understood that any tires 12 may be compared to one another, as the selected group may include tires on the same axle 34 or all tires on the vehicle 14. In this example, all tires 12 on the vehicle 14 are in the selected group.

[0075] The trend of the pressure indication 36 is evaluated as to whether the indicated pressure is above the recommended cold pressure 38 based on the recommended cold pressure 38. Of the ten (10) tires 12, six are above the recommended cold pressure 38, tires 12A, 12C, 12D, 12H, 12I, and 12J. Two (2) tires 12E and 12G are at the recommended cold pressure 38, and two (2) tires 12B and 12F are below the recommended cold pressure. Based on this, the trend is that the pressure indication 36 is above the recommended cold pressure 38.

[0076] The pressure indications 36 of the tires 12 following the trend are averaged. In this example, the pressure indications in tires 12A, 12C, 12D, 12H, 12I, and 12J are added together to yield a total pressure of 760 PSI. The total pressure of 760 PSI is divided by the number of tires in the trend, i.e., six (6), to yield an average pressure of 126.67 or 127 PSI, which is the adjusted recommended pressure 42. The adjusted recommended pressure 42 accounts for the temperature or thermal effects on the tires 12. The adjusted low pressure threshold 44 is set below the adjusted recommended pressure 42. In this example, the adjusted low pressure threshold 44 is 15 PSI below the adjusted recommended pressure 42, i.e., 112 PSI.

[0077] Using the adjusted recommended pressure 42 and the adjusted low pressure threshold 44, four (4) tires 12B, 12E, 12F, and 12G are below the threshold. The drive-through reader 26 generates a notification 46 for each tire 12B, 12E, 12F, and 12G that is below the adjusted low pressure threshold 44. Thus, the system 10 compensates the pressure indication 36 for the temperature effects on each tire 12 due to the operation of the vehicle 14.

[0078] The system 10 accounts for situations where the tire 12 has been operating at cold ambient temperatures and may produce an artificially low pressure indication 36 due to such low temperatures. When the tire 12 has been operating at low ambient temperatures, the pressure indication 36 may trend below the recommended cold pressure 38. In this case, when the pressure indications 36 following this trend are averaged, the resulting adjusted recommended pressure 42 may be below the recommended cold pressure 38, thereby accounting for cold temperature operation.

[0079] It should be understood that other pressure and temperature conversions may be used without affecting the overall concept or operation of the present invention. For example, extremely high and / or extremely low indications may be ignored, an arithmetic mean may be used instead of an average, and / or a conversion of a pressure difference to a temperature factor and back to an adjusted recommended pressure 42 may be used.

[0080] Go to Figure 5 As described above, the system 10 includes and is incorporated into the drive-by reader 26. When a notification 46 is generated, it is sent to a receiving device 50 along with any other relevant drive-by reader output via a wireless or wired transmission 48. The receiving device 50 may be any device that communicates the notification 46 to a technician, vehicle operator, or fleet manager, such as a computer with a display terminal, a user device, and / or a fleet management server.

[0081] In this manner, the system 10 for compensating drive-by reader tire pressure measurements accounts for and compensates for high temperature effects on the tire 12 due to operation of the vehicle 14. By using an adjusted recommended pressure 42 that accounts for temperature, rather than the recommended cold pressure 38, the likelihood that a tire 12 having a low pressure will be recognized by the drive-by reader 26 is reduced. The system 10 performs its compensation without requiring intrusion or access to the tire cavity, and without requiring a specific temperature sensor in the tire 12 or a drive-by reader 26.

[0082] The present invention also includes a method for compensating for the effects of high temperature on tire 12 due to vehicle operation in drive-by reader tire pressure measurements. The method includes the method according to the above presentation and in Figures 1 to 5 The steps of the description are shown in FIG.

[0083] It should be understood that the steps and accompanying structure of the above-described system and method for compensating drive-by reader tire pressure measurements of the present invention 10 may be changed or rearranged, or components or steps known to those skilled in the art may be omitted or added without affecting the overall concept or operation of the present invention.

[0084] The present invention has been described with reference to preferred embodiments. Others will appreciate possible modifications and variations after reading and understanding this description. It should be understood that all such modifications and variations are included within the scope of the present invention as set forth in the appended claims or their equivalents.

Claims

1. A system for compensating drive-by reader tire pressure measurements, the system comprising: driving past a reader, including a sensor array; an indication of pressure determined by the drive-by reader for each tire in a set of tires; Recommended cold pressure for tires; an adjusted recommended pressure for the tire, the adjusted recommended pressure being determined by the pressure indication and the recommended cold pressure, the adjusted recommended pressure accounting for an effect of temperature on the tire; The adjusted low pressure threshold is set at a predetermined level below the adjusted recommended pressure; as well as A notification is generated by the drive-by reader for each tire, the notification including the pressure indication being below the adjusted low-pressure threshold.

2. The system for compensating drive-by reader tire pressure measurements of claim 1, wherein: The adjusted recommended pressure includes an assessment of whether the pressure indicates a trend above or below the recommended cold pressure.

3. The system for compensating drive-by reader tire pressure measurements of claim 2, wherein: The adjusted recommended pressure includes an average of the pressure indications following the trend.

4. The system for compensating drive-by reader tire pressure measurements of claim 3, wherein: The adjusted recommended pressure includes ignoring at least one of a very high pressure indication and a very low pressure indication.

5. The system for compensating drive-by reader tire pressure measurements of claim 2, wherein: The adjusted recommended pressure comprises an arithmetic mean of the pressure indications following the trend.

6. The system for compensating drive-by reader tire pressure measurements of claim 1, wherein: The adjusted recommended pressure includes the conversion of the pressure difference to a temperature factor.

7. The system for compensating drive-by reader tire pressure measurements of claim 1, wherein: The adjusted low pressure threshold is fifteen pounds per square inch lower than the adjusted recommended pressure.

8. The system for compensating drive-by reader tire pressure measurements of claim 1, wherein: The tire set includes tires on the same axle.

9. The system for compensating drive-by reader tire pressure measurements of claim 1, wherein: The tire set includes all tires on the vehicle.

10. The system for compensating drive-by reader tire pressure measurements of claim 1, wherein: The notification is sent to a receiving device, which includes at least one of a computer with a display terminal, a user device, and a fleet management server.

11. The system for compensating drive-by reader tire pressure measurements of claim 1 , wherein: The system determines the adjusted recommended pressure without intruding into the cavity of each tire.

12. The system for compensating drive-by reader tire pressure measurements of claim 1, wherein: The system determines the adjusted recommended pressure without a temperature sensor.

13. A method for compensating drive-by reader tire pressure measurements, the method comprising the steps of: providing a drive-by reader, the drive-by reader comprising a sensor array; determining a pressure indication for each tire in a set of tires using the drive-by reader; providing a recommended cold pressure for the tire; determining an adjusted recommended pressure for the tire from the pressure indication and the recommended cold pressure, the adjusted recommended pressure accounting for the effect of temperature on the tire; setting an adjusted low pressure threshold at a predetermined level below the adjusted recommended pressure; as well as A notification is generated for each tire using the drive-by reader, the notification including the indication that the pressure is below the adjusted low-pressure threshold.

14. The method for compensating drive-by reader tire pressure measurements of claim 13, wherein: The step of determining an adjusted recommended pressure includes evaluating a tendency of said pressure indication to be above or below said recommended cold pressure.

15. The method for compensating drive-by reader tire pressure measurements of claim 14, wherein: The step of determining an adjusted recommended pressure comprises averaging said pressure indications following said trend.

16. The method for compensating drive-by reader tire pressure measurements of claim 15, wherein: The step of determining an adjusted recommended pressure includes ignoring at least one of a very high pressure indication and a very low pressure indication.

17. The method for compensating drive-by reader tire pressure measurements of claim 14, wherein: The step of determining an adjusted recommended pressure comprises calculating an arithmetic mean of said pressure indications following said trend.

18. The method for compensating drive-by reader tire pressure measurements of claim 13, wherein: The step of determining the adjusted recommended pressure includes converting the pressure differential to a temperature factor.

19. The method for compensating drive-by reader tire pressure measurements of claim 13, wherein: Said tire set includes all snake tires on the vehicle.

20. The method for compensating drive-by reader tire pressure measurements of claim 13, further comprising the step of sending the notification to a receiving device, the receiving device comprising at least one of a computer with a display terminal, a user device, and a fleet management server.

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