TWM594686U - Capacitance tire thickness sensor - Google Patents

Abstract

The present invention provides a capacitance tire thickness sensor, which comprises a capacitance sensing structure and a controller. The capacitance sensing structure includes two conductive electrodes and an insulating medium disposed between thereof. The capacitance sensing structure is disposed on or integrally formed with the tire surface. The controller electrically connects to the two conductive electrodes of the capacitive sensing structure and detects the capacitance between two conductive electrodes to obtain a capacitance value, and obtains the tire thickness from the capacitance value.

Description

Variable volume tire thickness sensor

This creation is about a tire thickness sensor, especially a tire thickness sensor that detects the tire thickness based on the change in capacitance.

According to the investigation of the Road Traffic Safety Steering Committee of the Ministry of Transport, in 2016, there were as many as 370 tire blowouts on the national highway, 200 of which were the separation of cars and tires, and the peeling of tire skin was as high as 7,585; in addition, the investigation also pointed out that from 2009 to 2015 In 2014, there were 2,786 tire punctures on the national highway, 2,033 of which caused vehicle damage, and 753 casualties, with a casualty rate of up to 27%; this type of situation, in addition to affecting the safety of the driver, What's more, it may further cause a serial car accident and cause serious casualties.

The occurrence of a flat tire, except for the intrusion of foreign objects and the flat tire pressure caused by the flat tire, the main cause is the lack of tire skin thickness. The lack of tire skin thickness not only affects the vehicle's tire grip, when the tire skin thickness is below the safety limit, the tire will also easily burst from areas with insufficient strength on the tread, causing the tire to burst.

In view of the above problems, the current mainstream tire skin thickness detection is directly judged by visual inspection. The judgment criterion is that the tire tread must be 1.6mm above the safety line to meet the safety standards; in addition to the visual inspection method, the most mainstream method It is to directly measure the depth of the tire pattern through a tool (tire tread depth measuring device) to determine whether it meets the safety standards. The above two methods rely on the independent judgment of the owner or the maintenance plant personnel. In the automatic detection technology, part of the technology is to place a wire on the inside of the tire in an embedded manner. By judging whether the wire is broken, confirm whether the tire has been used in a warning position, and confirm the status of the tire; in a non-invasive way, For example, CN106827974A patent is to actively send signals through ultrasound, and calculate the thickness of the tire skin through the time difference between ultrasound transmission and reception.

The above-mentioned invasive and non-invasive tire skin detection devices have their limitations in use, it is difficult to implement with existing tires, and it is difficult to meet the actual needs of today's consumers.

In order to achieve the above purpose, the author provides a variable-capacity tire thickness sensor, which includes a capacitance sensing unit and a controller. The capacitive sensing unit includes two conductive electrodes and an insulating medium disposed between the two conductive electrodes. The capacitive sensing unit is provided or integrally formed on the tire surface. The controller is electrically connected to the two conductive electrodes of the capacitance sensing unit, and detects the capacitance value between the two conductive electrodes to obtain the capacitance value of the two conductive electrodes, which is calculated and obtained from the capacitance value Tire thickness.

Further, one side of the two conductive electrodes and the insulating medium of the capacitance sensing unit is the wear side toward the tire surface.

Further, the capacitance sensing unit is exposed or buried on the tire surface.

Further, the controller pre-stores a threshold value, and outputs a warning signal when the tire thickness or the capacitance value is lower than the predetermined value.

Further, the variable volume tire thickness sensor includes a communication module connected to the controller. After calculating and obtaining the tire thickness, the controller transmits the tire thickness through the communication module through wireless transmission To a reader.

Further, the variable-capacity tire thickness sensor includes a power supply connected to the controller, the power supply is connected to the communication module and is generated by the communication module coupled to the reader Of resonance current.

Further, the communication protocol adopted by the communication module is radio frequency identification (RFID), wireless fidelity (WiFi), Zigbee, Bluetooth, global mobile communication system (GSM), third Generation communication system (3G), or the fourth generation communication system (4G).

Further, the controller obtains a look-up table after storing or loading into the storage unit, the look-up table includes a database using the capacitance value as an index of the tire thickness.

Further, when the obtained capacitance value does not appear in the lookup table, the controller calculates and obtains the tire thickness by an interpolation algorithm.

Therefore, this creation can effectively detect the thickness of the tire at a relatively low power state and reduce the power consumed by the sensor during operation. On the other hand, its better versatility can be implemented with most existing tires, and has Higher reliability.

The detailed description and technical content of this creation are explained below in conjunction with the drawings. The drawings in this creation are just examples of implementation patterns and their proportions are not necessarily drawn according to actual proportions. The pattern and proportions of these drawings are not intended to limit the patent scope of this case, and are described here first.

This creative system can be used in conjunction with a driving computer (ECU) or a vehicle head unit (Head Unit). It is set when the vehicle leaves the factory to meet the manufacturer's customized needs, and cooperates with original vehicle components or auxiliary factory vehicle components. The central control system detects and cooperates with the operation of each component; this creation can also be implemented through a third-party device attached to the vehicle, using the third-party control system to cooperate with the original vehicle component or the auxiliary factory vehicle component to obtain the vehicle Driving data of each component.

The driving data that can be processed by the central control system or the third-party control system includes the vehicle's engine working index (such as fuel injection, air-fuel ratio control, engine speed, etc.), tire conditions (such as tire pressure index, tire abnormality, tire skin thickness index, etc.) ), or user experience equipment (such as air conditioning control, driving recorder, audio, navigation, display, etc.); through the central control system or third-party control system, users can confirm the status of the vehicle in real time through the man-machine interface, or When the abnormal state is directly detected by the human-machine interface, the system actively feedbacks the abnormal prompt to the driver or user through the system, so that the user can immediately detect the condition of the vehicle and take necessary measures. In addition to the above structure, the central control system or third-party control system can also connect the user's mobile device through wireless means (such as Wi-Fi LAN, Bluetooth device, radio frequency identification, etc.), and detect the vehicle's status.

This creation can be applied to the above architecture to detect the thickness of the tire skin of the vehicle, and to detect the thickness parameters of the tire skin of the vehicle in real time through a central control system or a third-party control system. The following please refer to "Figure 1" and "Figure 2", which is a block schematic diagram and structural schematic diagram of creating a variable-capacity tire thickness sensor, as shown in the figure:

This creation discloses a variable-capacity tire thickness sensor 100, which is installed on the tire or inside the tire to detect the thickness of the tire skin through the capacitance or the amount of change in the capacitance. The tire or the inner position of the tire includes being directly placed on the tire, embedded in the inner side of the tire, attached to the wall surface of the inner side of the tire, attached to the wall surface of the inner rim of the tire, or placed near the tire The above-mentioned location is not the scope of this creation.

The following describes the detailed structure of the original variable-capacity tire thickness sensor 100. The original sensor 100 mainly includes a capacitive sensing unit 10, a communication module 20, a power supply 30, and a connection To the controller 40 of the capacitance sensing unit 10, the communication module 20, and the power supply 30.

The capacitive sensing unit 10 includes two conductive electrodes 11 and an insulating medium 12 disposed between the two conductive electrodes 11. The capacitive sensing unit 10 is provided or integrally formed on the tire surface. In a preferred embodiment, as shown in FIG. 2, the two sides of the conductive electrode 11 and the insulating medium 12 of the capacitance sensing unit 10 are used as the wear side 13 toward the tire surface, and the wear side 13 is It can be exposed or buried on the surface of the tire, this part is not limited in this creation. The controller 40 can be directly connected to the capacitive sensing unit 10 to be electrically connected to the conductive electrode 11 or electrically connected to the conductive electrode 11 through a wire embedded in the tire, which is not limited in this creation.

The communication module 20 is connected to the controller 40, and the communication module 20 is coupled to the reader 200 (central control system or third-party control system) by wireless transmission, whereby the reader 200 The data of the controller 40 can be accessed to collect tire data. The reader 200 uses a high-frequency electromagnetic wave to transmit a signal to the communication module 20. After receiving the high-frequency electromagnetic wave, the antenna of the communication module 20 resonates inside the antenna to generate electricity to activate the controller 40. The controller 40 receives After transmitting the signal, the response signal is transmitted back to the fetcher 200 in reverse. The communication module 20 can be connected to the reader 200 in a frequency-divided manner to separate the channel for supplying power from the channel for transmitting data, so that the communication module 20 can pass through radio frequency identification (RFID), wireless fidelity (Wi -Fi), Bluetooth, Zigbee, GSM, third-generation communication system (3G), fourth-generation communication system (4G), etc. or other types of communication protocols message. The above communication agreement is not within the scope of this creation.

The power supply 30 is connected to the communication module 20. The power supply 30 is used to obtain resonance electric power through the communication module 20 and pre-process the resonance current and feed it in to start and enable it. The controller 40. In a preferred embodiment, the power supply 30 may be, for example, a filter, an AC-DC converter, a transformer, or other such pre-processing circuits, which is not limited in this creation.

The controller 40 is connected to the capacitance sensing unit 10, the communication module 20, and the power supply 30 to coordinate the operation of the devices. In a preferred embodiment, the controller 40 may be a microprocessor, which is activated after being enabled by the power supply 30 and executes the corresponding algorithm.

The controller 40 is electrically connected to the two conductive electrodes 11 of the capacitance sensing unit 10, and detects the capacitance value between the two conductive electrodes 11 to obtain the capacitance value of the two conductive electrodes. The value is calculated and the tire thickness is obtained. After calculating and obtaining the tire thickness, the controller 40 transmits the tire thickness to the reader 200 through the communication module 20 through wireless transmission. The calculation method of the tire thickness will be described in detail later by way of example. In a preferred embodiment, in order to warn the user, the controller 40 may pre-store a threshold, and output a warning signal to the buzzer, speaker, or display when the tire thickness or the capacitance value is lower than the threshold , To remind the user that the tire thickness of the vehicle is abnormal.

Please refer to "Figure 3" below for the working diagram of creating a variable-capacity tire thickness sensor, as shown in the figure:

The reader 200 can be implemented directly as the head unit of the vehicle, or by attaching the device to the vehicle in the form of a third-party device; the reader 200 is connected to the sensor 100 in a plurality of tires In the preferred embodiment, an omnidirectional antenna can be used to output electromagnetic wave signals to connect a plurality of sensors 100; although the position of the tire is fixed, when the sensor 100 is installed in the tire, it is likely to As the tire rotates and changes its position, in order to avoid the shielding phenomenon of the sensor 100 at some positions, it seems to be a reasonable method to install it with an omnidirectional antenna. However, although the tire will change the position of the sensor 100 due to rolling However, when it is implemented on a vehicle body at a relatively fixed position with a directional antenna, the lobe angle of the directional antenna lobe can also be appropriately expanded to be coupled to the plurality of sensors 100. If the sensor 100 is located at a relatively stable place on the vehicle (for example, near the tire, but not on the tire), the reader 200 may be coupled to a plurality of the sensors via a highly directional antenna感器100。 Sensor 100. In yet another preferred embodiment, the reader 200 can also use the sensor array to directionally send and receive signals through beamforming technology. By adjusting the parameters of the basic unit of the phase array, certain Signals at angles receive constructive interference, while signals at other angles receive destructive interference, thereby outputting multiple beams simultaneously.

The following describes the calculation method of the controller 40 to calculate the thickness of the tire skin in this creation, please refer to "Figure 4(A)", "Figure 4(B)" and "Figure 5", which are schematic diagrams of tire wear, Relevant schematic diagram of tire loss thickness and capacitance reduction, and schematic diagram of lookup table, as shown in the figure:

The controller 40 stores or loads the storage unit to obtain a look-up table. The look-up table includes a database that uses the capacitance value as an index for the tire thickness. The controller 40 uses an interpolation algorithm to calculate and obtain the tire thickness when the obtained capacitance value does not appear in the look-up table.

Please refer to "Figure 4(A)" first. When the capacitance sensing unit 10 rubs against the ground, the conductive electrode 11 and the insulating medium 12 between them will be degraded with friction. Without considering changes in environmental factors, the conductive The reduced thickness T of the electrode 11 and the insulating medium 12 therebetween should be linearly related to the value of capacitance reduction (as shown in FIG. 4(B)). Under the condition of linear correlation, the thickness of the conductive electrode and the insulation medium between it can be calculated and obtained through the value of the capacitance reduction (that is, the thickness of the tire, the embedded type must still add the capacitance sensing unit and the surface of the tire skin Thickness), and the thickness of the tire is calculated through the reduced thickness. For the influence of environmental factors, such as temperature and tire material, the correct tire thickness can be obtained by substituting correction parameters. The correction parameters are adjusted according to the general use environment and are not limited in this creation.

In another preferred embodiment, in order to reduce the complexity of the operation and increase the speed of the execution of the calculation, the controller 40 may store a lookup table or load the storage unit to obtain the lookup table. The lookup table includes The database with the capacitance value as the index of the thickness parameter, and the detected capacitance is substituted into the lookup table to find the corresponding tire thickness.

For example, as shown in "Figure 5", the obtained capacitance falls within the value of 125μF, and the corresponding tire skin thickness in the look-up table is 10mm, then the thickness of the tire can be determined to be 10mm. Similar to the situation described above, considering the different environments, basically a plurality of lookup tables can be directly stored in advance according to different environmental conditions (for example, according to temperature), the corresponding lookup table can be directly confirmed from the environmental situation, and then the corresponding lookup table Find the corresponding tire thickness.

In a preferred embodiment, when the capacitance value obtained by the controller 40 does not appear in the look-up table, the thickness parameter can be calculated and obtained through an interpolation algorithm. The calculation method of interpolation can be calculated by linear interpolation, or by the method of quadratic polynomial or cubic polynomial, which is not limited in this creation.

The above algorithm can also be applied to the detection of tire puncture warning. When detecting that the tire skin thickness reaches a critical value, it can simultaneously evaluate multiple tire conditions to provide tire rupture warning, such as reducing the tire thickness and tire pressure And/or abnormal sound amplitude is taken as a parameter into the formula calculation to obtain the remaining time of the flat tire and provide a flat tire warning.

In summary, this creation can effectively detect the thickness of the tire at a relatively low power state and reduce the power consumed by the sensor during operation. On the other hand, its better versatility can be implemented with most existing tires. At the same time, it has higher reliability.

The above has made a detailed description of this creation, but the above is only one of the preferred embodiments of this creation, but it cannot be used to limit the scope of the implementation of this creation, that is, all equals to the patent application of this creation Changes and modifications should still fall within the scope of this patent.

100: Variable volume tire thickness sensor 10: Capacitive sensing unit 11: Conductive electrode 12: Insulating medium 13: wear side 20: Communication module 30: Power supply 40: controller T: thickness 200: reader

FIG. 1 is a block diagram of the original variable-capacity tire thickness sensor.

FIG. 2 is a schematic structural diagram of the variable volume tire thickness sensor of the original creation.

Fig. 3 is a schematic diagram of the working of the variable volume tire thickness sensor.

Fig. 4(A), a schematic diagram of tire wear.

Fig. 4(B), a schematic diagram of the correlation between the reduced thickness of the tire and the reduction in capacitance

Figure 5. Schematic diagram of the lookup table.

100: Variable volume tire thickness sensor

10: Capacitive sensing unit

20: Communication module

30: Power supply

40: controller

200: reader

Claims (9)

A variable-capacity tire thickness sensor, including: A capacitive sensing unit, including two conductive electrodes, and an insulating medium disposed between the two conductive electrodes, the capacitive sensing unit is provided or integrally formed on the tire surface; and A controller is electrically connected to the two conductive electrodes of the capacitance sensing unit, and detects the capacitance value between the two conductive electrodes to obtain the capacitance value of the two conductive electrodes, and calculates from the capacitance value and Obtain the tire thickness. The variable-capacity tire thickness sensor according to claim 1, wherein one side of the two conductive electrodes and the insulating medium of the capacitance sensing unit faces the tire surface as a wear side. The variable-capacity tire thickness sensor according to claim 2, wherein the wear side is exposed or buried in the tire surface. The variable-capacity tire thickness sensor according to claim 1, wherein the controller prestores a threshold value, and outputs a warning signal when the tire thickness or the capacitance value is lower than the predetermined value. The variable-capacity tire thickness sensor according to claim 1, further comprising a communication module connected to the controller. After calculating and obtaining the tire thickness, the controller passes the tire thickness through the communication module The group is transmitted to a reader via wireless transmission. The variable-capacity tire thickness sensor according to claim 5, further comprising a power supply connected to the controller, the power supply is connected to the communication module and is coupled by the communication module The resonance current generated by the reader. The variable volume tire thickness sensor according to claim 6, wherein the communication protocol used by the communication module is radio frequency identification (RFID), wireless fidelity (WiFi), Zigbee, blue Bud (Bluetooth), Global System for Mobile Communications (GSM), Third Generation Communication System (3G), or Fourth Generation Communication System (4G). The variable-capacity tire thickness sensor according to claim 1, wherein the controller obtains a look-up table after storing or loading into the storage unit, the look-up table includes data using the capacitance value as the tire thickness index Library. The variable-capacity tire thickness sensor according to claim 8, wherein the controller calculates and obtains the tire thickness by an interpolation algorithm when the obtained capacitance value does not appear in the look-up table.

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