Method, system, and computer-readable medium for detecting wheel tread depth

A method, a system and a computer-readable medium for detecting a wheel tread depth include a first detector, a second detector and a processor. The first detector is configured to detect a moving distance of a vehicle moved by at least one wheel. The second detector is configured to detect a number of tunes of the wheel while the vehicle moves the moving distance. The processor is electrically connected to the first detector and the second detector. The processor is configured to compute a current diameter of the wheel according to the moving distance and the number of tunes of the wheel and determine a parameter of the tread pattern of the wheel according to the current diameter of the wheel and a reference value.

CROSS-REFERENCE TO RELATED APPLICATIONS

This non-provisional application claims priority under 35 U.S.C. § 119(a) on Patent Application No(s). 105106335 filed in Taiwan, R.O.C. on Mar. 2, 2016, the entire contents of which are hereby incorporated by reference.

TECHNICAL FIELD

The disclosure relates to a method, system and a non-transitory computer-readable medium for detecting wheel tread depth, more particularly to a method, system and a non-transitory computer-readable medium for determining the wheel tread depth using a vehicle's distance moved and a wheel's number of turns.

BACKGROUND

Wheels of common vehicles usually have a wheel rim and a tire, and the tread of the tire has a tread pattern to increase the traction and grip between the tire and the road surface for transportation safety, lower puncture rate or the reduction of other dangerous situations.

However, the tire comes in contact with the road surface and begins to wear down during usage, so the wheel tread depth of the tire will gradually get shallower. Therefore, after the tire has been used for a period of time, the wheel tread depth is usually used to determine whether the tire should be taken out of service. In the past, determining the wheel tread depth was usually done by estimating the wheel tread depth with the naked eye or by directly measuring it, but these conventional ways cannot accurately assure that the wheel tread depth is still sufficient, leading to the driver missing or not knowing the right time to replace the worn tire if neglecting to check the wheel tread depth.

SUMMARY

According to one or more embodiments, a method of detecting a wheel tread depth includes the following steps. Use a first detector to detect a moving distance that a vehicle is moved by at least one wheel. Use a second detector to detect the number of turns of a wheel of the vehicle in the moving distance. Calculate a current diameter of the wheel according to the moving distance and the number of turns. Determine a pattern parameter of the wheel according to the current diameter and a reference value.

According to one or more embodiments, a system of detecting a wheel tread depth includes a first detector, a second detector and a processor. The first detector is applicable to detect the moving distance that the vehicle is moved by at least one wheel. The second detector is applicable to detect the number of turns of a wheel of the vehicle in the moving distance. The processor is electrically connected to the first detector and the second detector and is applicable to calculate a current diameter of the wheel according to the moving distance and the number of turns and determine a pattern parameter of the wheel according to the current diameter and a reference value.

According to one or more embodiments, a non-transitory computer-readable medium is applicable to store executable instructions that when executed by a processor cause the processor to effectuate a method including the following steps. Drive a first detector to detect a moving distance that a vehicle is moved by at least one wheel. Drive a second detector to detect the number of turns of a wheel of the vehicle in the moving distance. Calculate a current diameter of the wheel according to the moving distance and the number of turns. Determine a pattern parameter of the wheel according to the current diameter and a reference value.

DETAILED DESCRIPTION

Please refer toFIG. 1toFIG. 3,FIG. 1is a schematic view of a vehicle with wheels in an embodiment of the disclosure,FIG. 2is a schematic view of a vehicle moving a moving distance in an embodiment of the disclosure, andFIG. 3is a functional block diagram of a system of detecting a wheel tread depth in an embodiment of the disclosure. In the figures, a detection system10is installed on a vehicle20. The vehicle20includes at least one wheel21, and the at least one wheel21is driven by a driving device to cause the vehicle20move. In practice, the vehicle20is, for example, a motorcycle, a car, a trailer of a combination vehicle or other suitable objects. The wheel21has a wheel rim and a tire, and the tire is fixed on the wheel rim and is filled with gas so that the wheel21has a tire pressure.

The detection system10includes a first detector11, a second detector13and a processor15. The first detector11is used to detect a moving distance of the vehicle20. The first detector11is, for example, a global positioning system (GPS) that is built in the vehicle20or in an event data recorder (EDR) installed in the vehicle20or is another device capable of detecting the moving distance of the vehicle20. For example, the moving distance of the vehicle20is calculated by the positioning function of the GPS or is perfected using the map information, and the disclosure is not limited thereto. In an embodiment, the first detector11may consider whether the vehicle20is activated and/or whether the wheel21starts rotating, to decide whether to start the detection of the moving distance of the vehicle20. In other words, the first detector11may not detect the moving distance of the vehicle20when the wheel21does not rotate but the vehicle20is moving. In practice, for example, if the vehicle20is being towed away, the wheel21of the vehicle20does not rotate, so the first detector11does not detect the moving distance of the vehicle20. For a concise description, the first detector11is disposed in the vehicle20in the figure; and in practice, the first detector may be disposed inside or outside the vehicle20, on the wheel21, or other position.

The second detector13is used to detect the rotation of the wheel21to obtain the number of turns and provide this data to the processor15. In an embodiment, the second detector13detects the number of turns of the wheel21when the vehicle20is moving a moving distance. In practice, the second detector13is, for example, a device built in the vehicle20for recording the number of turns of the wheel21, a G-sensor or other suitable detector. A person having ordinary skill in the art can design the position of the second detector13, e.g. on the wheel21, the vehicle20or any position, and this embodiment is not limited thereto.

The processor15is electrically connected to the first detector11and the second detector13, so as to calculate the current diameter of the wheel21according to the moving distance detected and obtained by the first detector11and the number of turns detected and obtained by the second detector13, and then determine the pattern parameter of the wheel21according to the current diameter of the wheel21and a reference value. For example, when the moving distance of the vehicle20, detected and obtained by the first detector11, is 100 km, the second detector13may detect and obtain 53859 turns during the 100 km movement of the vehicle20, so the processor15calculates the current diameter of the wheel21to be 591 mm (100×106÷53859π=591). The reference value is, for example, the diameter of a new wheel, the diameter of a new wheel minus the double of the wheel tread depth, or another suitable value. The pattern parameter of the wheel21is, for example, the current wheel tread depth of the wheel21, the abrasion variation of tread pattern, or other parameters related to the tread pattern of the wheel21. Particularly, for example, when the reference value is the diameter of a new wheel, and the processor15determines the abrasion variation of the tread pattern of the wheel21according to the obtained current diameter and the reference value. For example, when the reference value is the diameter of a new wheel minus the double of the wheel tread depth, the processor15determines the current wheel tread depth of the wheel21according to the obtained current diameter and the reference value. In the previous examples, the reference value is based on the diameter of a new wheel, but in practice, the diameter of a new wheel may be replaced by the initial diameter of the wheel21, such as the diameter predefined in the processor15, the current diameter previously calculated by the processor15, or other suitable initial values.

For example, the reference value is obtained from a specification database according to the wheel model by the processor15, or is directly preset in the processor15. Furthermore, the processor15is independently installed on the vehicle20. Optionally, the processor15and at least one of the first detector11and the second detector13are assembled into a device which will be disposed to either the vehicle20or the wheel21; and for example, the processor15and the first detector11are assembled into an event data recorder which will be disposed to a suitable position on the vehicle20, and the embodiment is not limited thereto. A person having ordinary skill in the art can selectively design the processor15to be electrically connected to the first detector11and the second detector13in the wired or wireless way according to a variety of dispositions of the first detector11, the second detector13and the processor15, and the embodiment is not limited to it.

Next, please refer toFIG. 1andFIG. 4.FIG. 4is a functional block diagram of a system of detecting a wheel tread depth in another embodiment of the disclosure. In the figure, the detection system30includes a first detector31, a monitoring device33, a processor35and an in-vehicle computer37. The monitoring device33includes a second detector331and a third detector332. The first detector31, the second detector331and the processor35are substantially the same as the first detector11, the second detector13and the processor15in the previous embodiment, and they are not repeatedly described hereinafter.

The in-vehicle computer37is, for example, built in or additionally installed in the vehicle20and is applicable to read data from various electronic control units (ECUs) in the vehicle20and then integrate these readings to calculate the real-time fuel consumption, mean fuel consumption, quantity of remaining fuel, range, engine speed, intake pressure, acceleration performance, temperature of liquid coolant of the vehicle20or other measurable information of the vehicle20. The processor35determines a first correction parameter according to a first vehicle event recorded by the in-vehicle computer37, and determines a second correction parameter according to a second vehicle event recorded by the in-vehicle computer37.

The first correction parameter is used to correct the moving distance detected by the first detector31, and the second correction parameter is used to correct the number of turns of the wheel21detected by the second detector331. For example, the first vehicle event is that the wheel21is locked as the vehicle20is still sliding after the driver slams on the brake. In this case, the number of turns of the wheel21detected by the second detector331stops increasing since the wheel21is locked, but the moving distance detected by the first detector31keeps increasing. The first detector31records an additional moving distance that the vehicle20goes into a slide in the first vehicle event, so the processor35decides the first correction parameter in response to the analysis of the first vehicle event read from the in-vehicle computer37, to correct the moving distance detected by the first detector31. For example, if the moving distance of the vehicle20detected by the first detector31is up to 10 km and the in-vehicle computer37records that the vehicle20additionally goes into a slide of 2 m in the moving distance of 10 km, the processor35may decide that the first correction parameter is 0.9998 (i.e. 1−0.002/10=0.9998) according to the first vehicle event, and then correct the moving distance to be 9.998 km (i.e. 10×0.9998=9.998).

The second vehicle event is, for example, that the wheel21is spinning with little or no traction as the vehicle20does not go forward after the driver slams on the accelerator. In this case, the number of turns of the spinning wheel21detected by the second detector331is increasing, but the moving distance detected by the first detector31does not increase. The second detector331records the additional number of turns of the spinning wheel21in the second vehicle event, so the processor35decides the second correction parameter in response to the analysis of the second vehicle event read from the in-vehicle computer37, to correct the number of turns detected by the second detector331. For example, if the moving distance of the vehicle20is up to 10 km as the number of turns of the wheel21detected by the second detector331is 541, and the in-vehicle computer37records that two of the 541 turns of the wheel21are accidentally produced by the spinning of the wheel21with lessened traction, the processor35may decide the second correction parameter to be 0.9963 (i.e. 1−2/541=0.9963) according to the second vehicle event, and then correct the number of turns to be 538.9 turns (i.e. 541×0.9963=538.9).

The processor35calculates the current diameter of the wheel21according to the corrected moving distance and the corrected number of turns. In this embodiment, the in-vehicle computer37may directly analyze the additional number of turns of the wheel21spinning or analyze the additional distance of the vehicle20sliding for the concise description; in another embodiment, the processor35reads the relevant parameters from the in-vehicle computer37to determine the additional number of turns of the wheel21spinning or analyze the additional distance of the vehicle20sliding and then correct the moving distance and the number of turns to calculate the current diameter of the wheel21; and however, this embodiment is not limited to it.

The third detector332is, for example, a tire pressure sensor to detect the tire pressure of a wheel31and send the tire pressure of the wheel31to the processor35. In an embodiment, the processor35determines a third correction parameter according to the tire pressure detected and obtained by the third detector332, and uses the third correction parameter to correct the current diameter. In practice, the tire pressure affects the aspect ratio of the wheel21; the higher the tire pressure, the larger the aspect ratio of the wheel21is. Also, the relatively large aspect ratio of the wheel21leads to the relatively-high height of the wheel and thus, affects how far the vehicle20moves as the wheel21rotates one turn. Therefore, the processor35determines the third correction parameter according to the tire pressure detected by the third detector332to correct the current diameter. For a particular operation, the processor35stores a relationship table for the tire pressure and the aspect ratio, so that the processor35looks up the aspect ratio in the table according to the tire pressure and then determines the third correction parameter according to the aspect ratio; and this embodiment is not limited to it. In practice, the third correction parameter decided according to the tire pressure may be used to correct the moving distance detected by the first detector31, or to correct the number of turns detected by the second detector331, so the current diameter of the wheel21may be calculated using the corrected moving distance or the corrected number of turns. In other words, the tire pressure of the wheel21is not limited to be detected while the current diameter of the wheel21is calculated. In an embodiment, the tire pressure of the wheel21is not limited to be detected when the vehicle is normally going forward, so the processor35decides the third correction parameter according to the tire pressure of the wheel21and corrects the moving distance or the number of turns using the third correction parameter, so as to calculate the current diameter of the wheel21.

In another embodiment, the second detector331is directly used to detect the tire pressure of the wheel21, and optionally, the monitoring device33including the second detector331and the third detector332is used to detect the number of turns and the tire pressure of the wheel21and is not limited to be disposed on the wheel21or other positions on the vehicle20.

Moreover, all of the foregoing first, second and third correction parameters may not be necessary; that is, one or more of the first, second or third correction parameters can be selected or added according to actual requirements to perfect the detect result. The above vehicle events used to determine the first and second correction parameters are exemplified for a concise description; and particularly, the first correction parameter and the second correction parameter are associated with the driver's driving behavior, so a person having ordinary skill in the art can, in view of the above description, use other data or events to decide the first correction parameter and the second correction parameter. Likewise, other data or detected data may be used to decide the third correction parameter, and this embodiment is not limited to this.

In another embodiment, the detection system30may calculate the current diameter of the wheel21many times during a route period to determine the variance of the wheel21. Specifically, the current diameter of the wheel21is calculated once per a predefined distance in a first route period that the vehicle20moves, and a variance function of the diameter of the wheel21is then determined according to these current diameters obtained during the first route period.

For example, the first route period is a period that the vehicle20moves about 100 km, the predefined distance is 10 km, and during this first route period, the processor15calculates the current diameter of the wheel21once per 10 km and obtains 10 pieces of the current diameter. The processor15determines the variance function of the diameter of the wheel21according to the variations in the 10 pieces of the current diameter.

Then, the processor35uses the variance function and a reference value to decide a pattern parameter of the wheel21. In this embodiment, the reference value is, for example, the wheel tread depth of a new tire, the wheel tread depth previously calculated, or other reference depth qualified to be a reference value, and the pattern parameter of the wheel21is the wheel tread depth of the wheel21. In practice, the processor35may obtain the variances in the wheel tread depth of the wheel21related to the first route period according to this variance function and may then calculate the wheel tread depth that the vehicle20moves for the first route period, according to the wheel tread depth previously calculated. Similarly, the wheel tread depth obtained when the vehicle20moves for the first route period this time may be used as a reference value for the next route period.

In this embodiment, through the variance function obtained during the first route period, the detection system may pre-estimate the variances in the wheel tread depth during a second route period, so as to notify the driver if the wheel should be replaced or not. Particularly, the detection system30may be connected to a satellite navigation system, and if the driver sets a second route period through the satellite navigation system, the detection system could, according to the variance function obtained during the first route period, determine whether the wheel tread depth of the wheel, obtained when the vehicle20moves for the second route period, is shorter than a predefined depth, so as to warn the driver. For example, the predefined depth is not limited to be the wheel tread depth with a relatively-low opportunity of the occurrence of flat tire, or other suitable values.

In another embodiment, the processor35may determine the average of the current diameters of the wheel21related to the first route period according to the current diameters obtained during the first route period. In the case of the following equation,

Ravg⁡(n⁢⁢¨⁢⁢m)=∑k=nm⁢M⁡(ck)⁢BkMCk⁢π⁢⁢BkC⁢Pkm-n,
wherein M(Ck) represents, for example, a moving distance obtained by referring to the map information, Bkmrepresents, for example, a first correction parameter, Ckrepresents, for example, the number of turns of the wheel21, Bkcrepresents, for example, a second correction parameter, and Pkrepresents, for example, a third correction parameter. If k=n, the processor15may obtain the current diameter of the wheel related to the first piece of the 10 km moving distance; if k=n+1, the processor15may obtain the current diameter of the wheel related to the second piece of the 10 km moving distance; if k=m, the processor15may obtain the current diameter of the wheel related to the tenth piece of the 10 km moving distance; and the others can be deduced by analogy, and Ravg(n . . . m) is the average of the (m-n) pieces of current diameter.

Accordingly, Ravg(1 . . . n) may be understood as the average of the front n pieces of current diameter of a new tire in the beginning of usage, and may be a reference value used to calculate the wheel tread depth by the processor35every time; and for example, the following equation is used to calculate the wheel tread depth:

d(n⁢⁢¨⁢⁢m)=dfirst-Ravg⁡(1⁢⁢¨⁢⁢n)-Ravg⁡(n⁢⁢¨⁢⁢m)2,
wherein dfirstis the wheel tread depth of a new tire.

For the clarification of the detection method used in the detection system, please refer toFIGS. 1, 3 and 5, andFIG. 5is a flow chart of a method of detecting a wheel tread depth in an embodiment of the disclosure. The method includes the following steps. In step S401, the first detector11is used to detect the moving distance that the vehicle20moves. In step S403, the second detector13is used to detect the number of turns that the wheel21rotates when the vehicle20moves the moving distance. In step S405, the moving distance and the number of turns are used to calculate the current diameter of the wheel21. In step S407, the current diameter and a reference value are used to determine a pattern parameter of the wheel21. In the disclosure, the method has been described in the foregoing embodiments and thus, is not repeatedly described hereinafter.

Next, please refer toFIG. 6, andFIG. 6is a flow chart of the operation of a processor executing a non-transitory computer-readable medium in an embodiment of the disclosure. The aforementioned detection method of the wheel tread depth may particularly be carried out on a vehicle's computer system, an in-vehicle computer or other suitable devices. In other words, the detection method of the wheel tread depth may be effectuated when executable instructions made by computer programming languages are executed by a processor in the vehicle's computer after read from a non-transitory computer-readable medium. When the computer's processor executes the executable instructions stored in the non-transitory computer-readable medium for the detection method of the wheel tread depth in the embodiment, the method includes steps as shown inFIG. 5. In step S501, the processor drives a first detector to detect the moving distance of a vehicle. In step S503, the processor drives a second detector to detect the number of turns of a wheel when the vehicle moves the moving distance. In step S505, the moving distance and the number of turns are used to calculate the current diameter of the wheel. In step S507, the current diameter and a reference value are used to determine a pattern parameter of the wheel. A person having ordinary skill in the art should understand in view of the foregoing embodiments that the processor reads the executable content from the non-transitory computer-readable medium in this embodiment, and it will not repeatedly be described hereinafter.

As set forth above, the disclosure, providing a method, system and non-transitory computer-readable medium to detect the wheel tread depth, employs two different detectors to detect the moving distance that a vehicle is moving, and the number of turns that a wheel rotates. Then, the disclosure uses this information to accurately calculate and determine a pattern parameter of the wheel, such as the wheel tread depth or the variation of the wheel tread depth, to reduce the possibility that the wheel's tire is punctured because of the deficient wheel tread depth. In another embodiment, the disclosure further employs map information, an in-vehicle computer, a tire pressure sensor or other available devices to determine various situations occurring to the vehicle that is moving, thereby correcting the moving distance, the number of turns and the current diameter for the more accurate calculation of the wheel tread depth. Moreover, the disclosure may detect the variation of the wheel tread depth to estimate the variation of the wheel tread depth related to the next route period and according to the estimation, warn the driver of replacing the worn tire, so it may reduce the driver missing the right time to replace the worn tire if neglecting to check the wheel tread depth.