Clock calibration apparatus, method and tire pressure monitoring system
By introducing a clock calibration device into the tire pressure sensing device, the LFO clock frequency offset is dynamically corrected, which solves the problem of duty cycle offset caused by temperature changes, extends the sensor life and improves the reliability of the monitoring system.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SHENZHEN SHUMA ELECTRONICS TECH
- Filing Date
- 2022-10-13
- Publication Date
- 2026-06-05
AI Technical Summary
In existing tire pressure monitoring systems, the LFO clock frequency of the tire pressure sensing device is easily affected by temperature changes, leading to a shift in the working cycle, which affects the sensor lifespan and the reliability of the monitoring system. Static calibration methods cannot correct the frequency shift caused by temperature changes in a timely manner.
A clock calibration device is adopted, including a temperature reading module, a query module, a calibration judgment module, a calibration module, and a clock calibration module. By reading the working temperature, querying the corresponding clock buffer data, judging and generating calibration data, and modulating the clock signal frequency to achieve the target frequency, dynamic calibration is achieved.
It effectively extends the service life of the tire pressure sensing device, improves the reliability of the monitoring system, reduces power consumption, and ensures the timeliness and accuracy of data acquisition.
Smart Images
Figure CN115556517B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of clock calibration technology, and in particular to a clock calibration device, method and tire pressure monitoring system. Background Technology
[0002] With the formal implementation of the mandatory standard for Tire Pressure Monitoring Systems (TPMS) in China, public attention to TPMS has been increasing. TPMS is primarily used for real-time monitoring and alarm of tire pressure in passenger vehicles during operation. By promptly detecting tire leaks or low pressure, occupants can take appropriate measures to ensure adequate tire pressure, thereby improving fuel economy and driving safety.
[0003] Tire pressure monitoring sensors (TPMS) cannot be connected to the vehicle via cables during operation, so they are all battery-powered. The TPMS sensor's built-in Periodic Wake-Up (PWU) module allows the sensor to wake from sleep mode periodically, thus achieving low power consumption. The PWU module is typically driven by a 1kHz low-frequency clock crystal oscillator (LFO). However, the actual operating frequency of the LFO clock varies between different sensors and is significantly affected by factors such as temperature. Frequency deviation of the LFO clock directly affects the PWU's operating frequency, thereby affecting the sensor's wake-up cycle and having a significant impact on the sensor's lifespan and the reliability of the monitoring system. Increasing the frequency may cause the sensor to wake from sleep mode more frequently than normal, increasing overall power consumption and reducing sensor lifespan; decreasing the frequency causes a lag in the sensor's periodic wake-up time, resulting in data acquisition delays and affecting the reliability of the vehicle monitoring system.
[0004] The common solution currently is to perform an LFO clock calibration at the sensor's factory. This static calibration method improves the LFO clock frequency offset caused by manufacturing to some extent and corrects the sensor's initial duty cycle. However, it cannot promptly correct the duty cycle offset caused by temperature changes due to the LFO clock frequency offset. Therefore, how to dynamically and promptly correct the duty cycle offset caused by temperature changes during sensor operation, extend the sensor's lifespan as much as possible, and ultimately improve the reliability of the monitoring system has become an urgent problem to be solved. Summary of the Invention
[0005] This application provides a clock calibration device, method, and tire pressure monitoring system capable of dynamically calibrating the working cycle offset of a tire pressure sensing device.
[0006] A clock calibration device is applied to a tire pressure sensing device, the clock calibration device comprising:
[0007] A temperature reading module is used to read the operating temperature of the tire pressure sensing device when the tire pressure sensing device is in a wake-up reset state.
[0008] The query module, connected to the temperature reading module, is used to query clock buffer data corresponding to the operating temperature;
[0009] A calibration determination module, connected to the query module, is used to determine whether the clock buffer data is consistent with the initial data and generate a determination result;
[0010] A calibration module, connected to the calibration determination module, is used to obtain clock calibration data based on the determination result;
[0011] A clock calibration module is used to connect to the tire pressure sensing device and the calibration module, and to modulate the clock signal of the tire pressure sensing device according to the clock calibration data so that the frequency of the modulated clock signal reaches the target frequency.
[0012] In some embodiments, the correction module is further configured to, if the determination result is that the clock buffer data is consistent with the initial data, obtain the clock signal frequency of the tire pressure sensing device and generate the clock correction data according to the clock signal frequency.
[0013] In some embodiments, the correction module includes:
[0014] The measurement unit, connected to the calibration determination module, is used to measure the clock signal period of the tire pressure sensing device in multiple time periods if the determination result is that the clock buffer data is consistent with the initial data.
[0015] The calculation unit, connected to the measurement unit, is used to filter each clock signal period that falls within a preset range to obtain an effective clock period, and to calculate the average value of the effective clock periods to obtain the clock signal frequency.
[0016] In some embodiments, the correction module further includes:
[0017] A conversion unit, connected to the calculation unit and the clock calibration module respectively, is used to input the clock signal frequency into the conversion model to obtain the clock correction data;
[0018] The transformation model is represented as follows:
[0019] Coef = (1000f - 504) / 16
[0020] Wherein, Coef is the clock correction data, and f is the clock signal frequency.
[0021] In some embodiments, the query module is also connected to the tire pressure sensing device and is used to query the mapping table of sample temperature range and sample clock buffer data stored in the tire pressure sensing device to obtain the clock buffer data.
[0022] In some embodiments, the calibration module is also connected to the tire pressure sensing device to send the clock calibration data to the tire pressure sensing device to replace the clock buffer data.
[0023] In some embodiments, the clock calibration device further includes:
[0024] The reset determination module, connected to the temperature reading module, is used to determine whether the tire pressure sensing device is in the wake-up reset state.
[0025] In some embodiments, the reset determination module is further configured to determine whether the tire pressure sensing device is in a power-on reset state;
[0026] The clock calibration device also includes:
[0027] An initialization module, connected to both the reset determination module and the tire pressure sensing device, is used to set the sample clock buffer data of the mapping table as the initial data if the tire pressure sensing device is in the power-on reset state.
[0028] In some embodiments, the correction module is further configured to use the clock buffer data as the clock correction data if the determination result is that the clock buffer data is inconsistent with the initial data.
[0029] A tire pressure monitoring system, comprising:
[0030] Tire pressure sensing device;
[0031] And the clock calibration device described in any of the above embodiments.
[0032] A clock calibration method applied to a tire pressure sensing device, the method comprising:
[0033] When the tire pressure sensing device is in the wake-up reset state, the operating temperature of the tire pressure sensing device is read.
[0034] Query the clock buffer data corresponding to the operating temperature;
[0035] Determine whether the clock buffer data is consistent with the initial data, and generate a determination result;
[0036] Obtain clock correction data based on the determination result;
[0037] The clock signal of the tire pressure sensing device is modulated according to the clock correction data so that the frequency of the modulated clock signal reaches the target frequency.
[0038] The aforementioned clock calibration device is applied to a tire pressure sensing device. The clock calibration device includes a temperature reading module, a query module, a correction judgment module, a correction module, and a clock calibration module. When the tire pressure sensing device is in a wake-up / reset state, the temperature reading module reads the operating temperature of the tire pressure sensing device. Then, the query module queries the clock buffer data corresponding to the operating temperature. The correction judgment module determines whether the clock buffer data is consistent with the initial data and generates a judgment result. The correction module obtains clock correction data based on the judgment result. Finally, the clock calibration module modulates the clock signal of the tire pressure sensing device based on the clock correction data, so that the frequency of the modulated clock signal reaches the target frequency. This allows the tire pressure sensing device to dynamically correct its working cycle deviation caused by temperature changes during operation, thereby extending the service life of the tire pressure sensing device and ultimately improving the reliability of the monitoring system. Attached Figure Description
[0039] Figure 1 This is a structural block diagram of a clock calibration device according to an embodiment of this application;
[0040] Figure 2 This is a structural block diagram of a clock calibration device according to another embodiment of this application;
[0041] Figure 3 This is a structural block diagram of a clock calibration device according to another embodiment of this application;
[0042] Figure 4 This is a structural block diagram of a clock calibration device according to another embodiment of this application;
[0043] Figure 5 This is a structural block diagram of a clock calibration device according to another embodiment of this application;
[0044] Figure 6 This is a structural block diagram of a clock calibration device according to another embodiment of this application;
[0045] Figure 7 This is a structural block diagram of a clock calibration device according to another embodiment of this application;
[0046] Figure 8 This is a structural block diagram of a clock calibration device according to another embodiment of this application;
[0047] Figure 9 This is a structural block diagram of a clock calibration device according to another embodiment of this application;
[0048] Figure 10 This is a schematic flowchart of a clock calibration method according to an embodiment of this application. Detailed Implementation
[0049] It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit this application.
[0050] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.
[0051] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly. The connection can be a direct connection or an indirect connection.
[0052] Furthermore, the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. If the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed in this application.
[0053] Figure 1 This is a structural block diagram of a clock calibration device according to one embodiment, such as... Figure 1As shown, the clock calibration device is applied to the tire pressure sensing device 100. The clock calibration device includes a temperature reading module 101, a query module 102, a correction determination module 103, a correction module 104, and a clock calibration module 105. The temperature reading module 101 is used to read the operating temperature of the tire pressure sensing device 100 when the tire pressure sensing device 100 is in a wake-up and reset state. The query module 102 is connected to the temperature reading module 101 and is used to query the clock buffer data corresponding to the operating temperature. The correction determination module 103 is connected to the query module 102 and is used to determine whether the clock buffer data is consistent with the initial data and generate a determination result. The correction module 104 is connected to the correction determination module 103 and is used to obtain clock correction data according to the determination result. The clock calibration module 105 is connected to the tire pressure sensing device 100 and the correction module 104, and is used to modulate the clock signal of the tire pressure sensing device 100 according to the clock correction data so that the frequency of the modulated clock signal reaches the target frequency.
[0054] It is understood that the tire pressure sensing device 100 may be equipped with a periodic wake-up module to wake the tire pressure sensing device 100 from the sleep mode at a certain period. The wake-up reset state is the state of the tire pressure sensing device 100 when it is woken up by the periodic wake-up module. The temperature reading module 101 can read the operating temperature of the tire pressure sensing device 100 when the tire pressure sensing device 100 is in the wake-up reset state. The tire pressure sensing device 100 may be equipped with a temperature acquisition element to acquire the operating temperature of the tire pressure sensing device 100. The temperature reading module 101 can obtain the operating temperature of the tire pressure sensing device 100 by reading the data acquired by the temperature acquisition element.
[0055] The query module 102 can obtain clock buffer data corresponding to the operating temperature of the tire pressure sensing device 100 by querying a mapping table or mapping curve that shows the correspondence between operating temperature and clock buffer data.
[0056] To determine the validity of the obtained clock buffer data, initial data can be preset, and consistency determination is performed between the initial data and the clock buffer data by the correction determination module 103. The value of the initial data can be set manually by the user. After obtaining the determination result, the correction module 104 can obtain clock correction data in different ways according to the determination result. Then, the clock calibration module 105 modulates the clock signal of the tire pressure sensing device 100 according to the clock correction data so that the frequency of the modulated clock signal reaches the target frequency. Specifically, the clock calibration module 105 can generate a modulation signal according to the clock correction data, and then use the modulation signal to modulate the clock signal so that the frequency of the modulated clock signal reaches the target frequency. In one embodiment, the clock calibration module 105 can be equipped with a frequency divider, which can modulate the clock signal frequency when the clock signal frequency is higher than the target frequency.
[0057] In one embodiment, the tire pressure sensing device 100 may include a clock module 1001 and a periodic wake-up module, and a clock calibration module 105 may be connected to the clock module and the periodic wake-up module 1002 of the tire pressure sensing device 100, respectively. Figure 2 As shown, the clock calibration module 105 can modulate the clock signal output by the clock module according to the clock correction data so that the frequency of the modulated clock signal reaches the target frequency, and send the modulated clock signal to the periodic wake-up module, so that the tire pressure sensing device 100 can wake up according to the expected period.
[0058] The aforementioned clock calibration device, through the temperature reading module 101, reads the operating temperature of the tire pressure sensing device 100 when it is in a wake-up and reset state. Then, the query module 102 queries the clock buffer data corresponding to the operating temperature, and the correction judgment module 103 determines whether the clock buffer data is consistent with the initial data and generates a judgment result. The correction module 104 obtains clock correction data based on the judgment result. Finally, the clock calibration module 105 modulates the clock signal of the tire pressure sensing device 100 according to the clock correction data so that the frequency of the modulated clock signal reaches the target frequency. In this way, the tire pressure sensing device 100 can be dynamically corrected for the working cycle deviation caused by temperature changes during operation, thereby extending the service life of the tire pressure sensing device 100 and ultimately improving the reliability of the monitoring system.
[0059] In one embodiment, the correction module 104 is further configured to, if the determination result is that the clock buffer data is consistent with the initial data, obtain the clock signal frequency of the tire pressure sensing device 100 and generate clock correction data based on the clock signal frequency.
[0060] It is understandable that if the determination result of the correction determination module 103 is that the clock buffer data is consistent with the initial data, it indicates that the clock buffer data is invalid and valid clock buffer data needs to be obtained. At this time, the correction module 104 can obtain the clock signal frequency of the clock signal in the tire pressure sensing device 100, and then generate clock correction data according to the clock signal frequency, so that after the clock calibration module 105 uses the clock correction data to modulate the clock signal, the frequency of the clock signal reaches the target frequency.
[0061] The clock correction data can be directly used to instruct the clock calibration module 105 to perform corresponding modulation actions; the clock signal frequency can be mapped to the clock correction data, and the clock correction data can be obtained according to the clock signal frequency, thereby instructing the clock calibration module 105 to modulate the clock signal of the tire pressure sensing device 100.
[0062] In one embodiment, such as Figure 3As shown, the calibration module 104 includes a measurement unit 1041 and a calculation unit 1042. The measurement unit 1041 is connected to the calibration judgment module 103 and is used to measure the clock signal period of the tire pressure sensing device 100 in multiple time periods if the judgment result is that the clock buffer data is consistent with the initial data. The calculation unit 1042 is connected to the measurement unit 1041 and is used to filter each clock signal period that falls within a preset range to obtain the effective clock period and calculate the average value of the effective clock period to obtain the clock signal frequency.
[0063] It is understood that the measurement unit 1041 may include a reference measurement clock, which may be a high-speed clock built into the tire pressure sensing device 100, capable of measuring the period of the clock signal generated by the clock module within the tire pressure sensing device 100. Specifically, considering that the clock signal may fluctuate, the measurement unit 1041 may measure the clock signal period over multiple time periods. Then, the calculation unit 1042 filters the measured clock signal periods, selecting those falling within a preset range as valid clock periods. Specifically, the calculation unit 1042 may consider an 80% maximum frequency offset and filter clock signal periods between 0.2 times and 1.8 times the target period, where the target period is the reciprocal of the target frequency. After obtaining the valid clock periods, the calculation unit 1042 performs an average calculation on the valid clock periods to obtain the clock signal frequency. The calculation unit 1042 may further calculate the reciprocal of the average of the valid clock periods, using this reciprocal as the clock signal frequency.
[0064] In one embodiment, such as Figure 4 As shown, the correction module 104 also includes a conversion unit 1043, which is connected to the calculation unit 1042 and the clock calibration module 105 respectively. The conversion unit 1043 is used to input the clock signal frequency into the conversion model to obtain clock correction data. The conversion model is represented as:
[0065] Coef = (1000f - 504) / 16
[0066] Where Coef is the clock correction data and f is the clock signal frequency.
[0067] It is understood that in order to obtain clock correction data that can directly instruct the clock calibration module 105 to perform corresponding modulation actions, the clock signal frequency can be numerically converted by the conversion unit 1043 to obtain clock correction data.
[0068] In one embodiment, the query module 102 is also connected to the tire pressure sensing device 100, such as Figure 5 As shown, a mapping table is used to query the sample temperature range and sample clock buffer data stored in the tire pressure sensing device 100 to obtain the clock buffer data.
[0069] The tire pressure sensing device 100 may include a storage element for storing a mapping table of sample temperature range and sample clock buffer data. It is understood that, considering that the tire pressure sensing device 100 may only exhibit a significant clock offset when the temperature changes significantly, the mapping table or mapping curve can characterize the mapping relationship between the sample temperature range and the sample clock buffer data. The query module 102 can first determine the sample temperature range where the working temperature is located, and then index the corresponding sample clock buffer data, that is, the clock buffer data corresponding to the working temperature. For example, suppose that when the temperature change reaches 20°C, the frequency change of the clock module in the tire pressure sensing device 100 is more obvious. The extreme operating temperature range of the tire pressure sensing device 100 is -40°C to 125°C. In order to reduce the number of calibrations and thus reduce power consumption, the temperature can be divided into 8 intervals, namely [-40, -20°C], (-20, 0°C], (0°C, 20°C], (20°C, 40°C], (40°C, 60°C], (60°C, 80°C], (80°C, 100°C], and (100°C, 125°C]. A data buffer is used to store the sample clock buffer data corresponding to these 8 intervals.
[0070] In one embodiment, the calibration module 104 is also connected to the tire pressure sensing device 100 to send clock calibration data to the tire pressure sensing device 100 to replace the clock buffer data.
[0071] It is understood that, when the clock buffer data is consistent with the initial data, the calibration module 104 obtains the clock signal frequency and further obtains the clock calibration data, and then sends the clock calibration data to the tire pressure sensing device 100 to update the corresponding clock buffer data in the mapping table. This ensures that the updated clock buffer data is obtained the next time the mapping table is queried based on the same operating temperature. In this way, the calibration process of obtaining clock calibration data based on the clock signal frequency can be performed at most once per interval throughout the entire life cycle of the tire pressure sensing device 100, reducing unnecessary power consumption and extending the overall service life of the clock calibration device.
[0072] In one embodiment, when such Figure 6 As shown, when the calibration module 104 includes a measurement unit 1041, a calculation unit 1042, and a conversion unit 1043, the conversion unit 1043 is connected to the tire pressure sensing device 100 to send clock calibration data.
[0073] In one embodiment, such as Figure 7 As shown, the clock calibration device also includes a reset determination module 106, which is connected to the temperature reading module 101 and is used to determine whether the tire pressure sensing device 100 is in a wake-up reset state.
[0074] It is understood that the reset determination module 106 can be connected to the tire pressure sensing device 100, and can determine whether the tire pressure sensing device 100 is in a wake-up reset state by detecting the working state of the periodic wake-up module in the tire pressure sensing device 100. For example, if the periodic wake-up module is detected to be turned on, it indicates whether the tire pressure sensing device 100 is in a wake-up reset state.
[0075] In one embodiment, the reset determination module 106 is further configured to determine whether the tire pressure sensing device 100 is in a power-on reset state; the clock calibration device also includes an initialization module 107, such as Figure 8 As shown, the initialization module 107 is connected to the reset determination module 106 and the tire pressure sensing device 100 respectively, and is used to set the sample clock buffer data of the mapping table as the initial data if the tire pressure sensing device 100 is in the power-on reset state.
[0076] It can be understood that the power-on reset state is the state when the tire pressure sensing device 100 is turned on upon power-on. When in the power-on reset state, the initialization module 107 initializes the mapping table stored in the tire pressure sensing device 100, setting the sample clock buffer data to initial data. This facilitates the calibration determination module 103 in determining whether the calibration process at the current operating temperature has been executed, and whether it is still necessary to obtain clock calibration data by acquiring the clock signal frequency. The sample clock buffer data in each sample clock buffer in the mapping table can be set to the same initial data to reduce the design complexity of the calibration determination module 103.
[0077] In one embodiment, the correction module 104 is further configured to use the clock buffer data as clock correction data if the determination result is that the clock buffer data is inconsistent with the initial data.
[0078] It is understandable that if the determination result of the correction determination module 103 is that the clock buffer data is consistent with the initial data, it indicates that the clock buffer data is valid. At this time, it is only necessary to use the queried clock buffer data as the clock correction data, so that the clock calibration module 105 can use the clock correction data to modulate the clock signal and the frequency of the clock signal reaches the target frequency.
[0079] This invention also provides a clock calibration device, applied to the tire pressure sensing device 100, such as... Figure 9As shown, the clock calibration device includes a reset determination module 106, an initialization module 107, a temperature reading module 101, a query module 102, a correction determination module 103, a correction module 104, and a clock calibration module 105. The correction module 104 includes a measurement unit 1041, a calculation unit 1042, and a conversion unit 1043. The reset determination module 106, temperature reading module 101, query module 102, correction determination module 103, measurement unit 1041, calculation unit 1042, conversion unit 1043, clock calibration module 105, and tire pressure sensing device 100 are connected sequentially. The initialization module 107 is connected to both the reset determination module 106 and the tire pressure sensing device 100. The query module 102 and the conversion unit 1043 are also connected to the tire pressure sensing device 100. The specific working principle and beneficial effects of the clock calibration device in this embodiment can be found in the above-described clock calibration device embodiment, and will not be repeated here.
[0080] This invention also provides a tire pressure monitoring system, including a tire pressure sensing device and a clock calibration device of any of the above embodiments. The specific working principle and beneficial effects can be referred to the above clock calibration device, and will not be repeated here.
[0081] This invention also provides a clock calibration method applied to a tire pressure sensing device, the method including steps S110 to S150, such as... Figure 10 As shown.
[0082] Step S110: When the tire pressure sensing device is in the wake-up reset state, read the operating temperature of the tire pressure sensing device.
[0083] Step S120: Query the clock buffer data corresponding to the operating temperature.
[0084] Step S130: Determine whether the clock buffer data is consistent with the initial data, and generate a determination result.
[0085] Step S140: Obtain clock correction data based on the determination result.
[0086] Step S150: Modulate the clock signal of the tire pressure sensing device according to the clock correction data so that the frequency of the modulated clock signal reaches the target frequency.
[0087] The principle and beneficial effects of the clock calibration method in this embodiment can be referred to the clock calibration device described above, and will not be repeated here.
[0088] In one embodiment, obtaining clock correction data based on the determination result includes: if the determination result is that the clock buffer data is consistent with the initial data, then obtaining the clock signal frequency of the tire pressure sensing device, and generating clock correction data based on the clock signal frequency.
[0089] In one embodiment, obtaining the clock signal frequency of the tire pressure sensing device includes: if the determination result is that the clock buffer data is consistent with the initial data, then measuring the clock signal period of the tire pressure sensing device in multiple time periods; filtering each clock signal period that falls within a preset range to obtain the effective clock period, and calculating the average of the effective clock periods to obtain the clock signal frequency.
[0090] In one embodiment, if the determination result is that the clock buffer data is consistent with the initial data, then obtaining the clock signal frequency of the tire pressure sensing device and generating clock correction data based on the clock signal frequency includes: inputting the clock signal frequency into a conversion model to obtain clock correction data; the conversion model is represented as:
[0091] Coef = (1000f - 504) / 16
[0092] Where Coef is the clock correction data and f is the clock signal frequency.
[0093] In one embodiment, querying the clock buffer data corresponding to the operating temperature includes: querying a mapping table of sample temperature ranges and sample clock buffer data stored in the tire pressure sensing device to obtain the clock buffer data.
[0094] In one embodiment, after generating clock correction data based on the clock signal frequency, the clock calibration method further includes sending the clock correction data to the tire pressure sensing device to replace the clock buffer data.
[0095] In one embodiment, before reading the operating temperature of the tire pressure sensing device when the tire pressure sensing device is in a wake-up reset state, the clock calibration method further includes determining whether the tire pressure sensing device is in a wake-up reset state.
[0096] In one embodiment, the clock calibration method further includes: determining whether the tire pressure sensing device is in a power-on reset state; if the tire pressure sensing device is in a power-on reset state, then setting the sample clock buffer data of the mapping table to the initial data.
[0097] In one embodiment, obtaining clock correction data based on the determination result includes: if the determination result is that the clock buffer data is inconsistent with the initial data, then the clock buffer data is used as the clock correction data.
[0098] The present invention also provides a clock calibration method, including steps (a1) to (a8), step (b), and steps (c1) to (c2).
[0099] Step (a1): Determine whether the tire pressure sensing device is in the wake-up reset state.
[0100] Step (a2): When the tire pressure sensing device is in the wake-up reset state, read the operating temperature of the tire pressure sensing device.
[0101] Step (a3) queries the mapping table of sample temperature range and sample clock buffer data stored in the tire pressure sensing device to obtain the clock buffer data.
[0102] Step (a4) determines whether the clock buffer data is consistent with the initial data and generates a determination result.
[0103] In step (a5), if the determination result is that the clock buffer data is consistent with the initial data, the clock signal period of the tire pressure sensing device in multiple time periods is measured.
[0104] Step (a6) involves filtering out clock signal periods that fall within a preset range to obtain valid clock periods, and calculating the average of the valid clock periods to obtain the clock signal frequency.
[0105] Step (a7) involves inputting the clock signal frequency into the conversion model to obtain clock correction data; the conversion model is represented as:
[0106] Coef = (1000f - 504) / 16
[0107] Where Coef is the clock correction data and f is the clock signal frequency.
[0108] Step (a8) sends clock correction data to the tire pressure sensing device to replace the clock buffer data.
[0109] In step (b), if the determination result is that the clock buffer data is inconsistent with the initial data, then the clock buffer data is used as the clock correction data.
[0110] Step (c1) determines whether the tire pressure sensing device is in the power-on reset state.
[0111] Step (c2): If the tire pressure sensing device is in the power-on reset state, the sample clock buffer data of the mapping table is set to the initial data.
[0112] The specific principles and beneficial effects of the clock calibration method in this embodiment can be found in the above-described clock calibration method embodiments, and will not be repeated here.
[0113] It should be understood that, although the above Figure 10 In the flowchart, the steps are shown sequentially according to the arrows, and the steps S110 to S150 are shown sequentially according to the labels. However, these steps are not necessarily executed in the order indicated by the arrows or numbers. Unless explicitly stated herein, there is no strict order requirement for the execution of these steps; they can be executed in other orders. Figure 2 and Figure 4 At least some of the steps in the process may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but may be executed at different times. The execution order of these steps or stages is not necessarily sequential, but may be executed in turn or alternately with other steps or at least some of the steps or stages in other steps.
[0114] The above description is only a preferred embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural changes made based on the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.
Claims
1. A clock calibration device, characterized in that, The clock calibration device, used in tire pressure sensing devices, includes: A temperature reading module is used to read the operating temperature of the tire pressure sensing device when the tire pressure sensing device is in a wake-up reset state. The query module, connected to the temperature reading module, is used to query clock buffer data corresponding to the operating temperature; A calibration determination module, connected to the query module, is used to determine whether the clock buffer data is consistent with the initial data and generate a determination result; A calibration module, connected to the calibration determination module, is used to obtain clock calibration data based on the determination result; A clock calibration module is used to connect to the tire pressure sensing device and to the calibration module, and is used to modulate the clock signal of the tire pressure sensing device according to the clock calibration data, so that the frequency of the modulated clock signal reaches the target frequency. The calibration module is also connected to the tire pressure sensing device and is used for: If the determination result is that the clock buffer data is consistent with the initial data, then the clock signal frequency of the tire pressure sensing device is obtained, and the clock correction data is generated according to the clock signal frequency; the clock correction data is sent to the tire pressure sensing device to replace the clock buffer data. If the determination result is that the clock buffer data is inconsistent with the initial data, then the clock buffer data shall be used as the clock correction data; The query module is also connected to the tire pressure sensing device and is used to query the mapping table of sample temperature range and sample clock buffer data stored in the tire pressure sensing device to obtain the clock buffer data.
2. The clock calibration device according to claim 1, characterized in that, The correction module includes: The measurement unit, connected to the calibration determination module, is used to measure the clock signal period of the tire pressure sensing device in multiple time periods if the determination result is that the clock buffer data is consistent with the initial data. The calculation unit, connected to the measurement unit, is used to filter each clock signal period that falls within a preset range to obtain an effective clock period, and to calculate the average value of the effective clock periods to obtain the clock signal frequency.
3. The clock calibration device according to claim 2, characterized in that, The correction module also includes: A conversion unit, connected to the calculation unit and the clock calibration module respectively, is used to input the clock signal frequency into the conversion model to obtain the clock correction data; The transformation model is represented as follows: Coef=(1000f-504) / 16 Wherein, Coef is the clock correction data, and f is the clock signal frequency.
4. The clock calibration device according to claim 1, characterized in that, The clock calibration device also includes: The reset determination module, connected to the temperature reading module, is used to determine whether the tire pressure sensing device is in the wake-up reset state.
5. The clock calibration device according to claim 4, characterized in that, The reset determination module is also used to determine whether the tire pressure sensing device is in a power-on reset state. The clock calibration device also includes: An initialization module, connected to both the reset determination module and the tire pressure sensing device, is used to set the sample clock buffer data of the mapping table as the initial data if the tire pressure sensing device is in the power-on reset state.
6. A tire pressure monitoring system, characterized in that, include: Tire pressure sensing device; And the clock calibration device according to any one of claims 1 to 5.
7. A clock calibration method, characterized in that, The method, applied to the clock calibration device of claim 1, wherein the clock calibration device is applied to the tire pressure sensing device, comprises: When the tire pressure sensing device is in the wake-up reset state, the operating temperature of the tire pressure sensing device is read. Query the clock buffer data corresponding to the operating temperature; Determine whether the clock buffer data is consistent with the initial data, and generate a determination result; Obtain clock correction data based on the determination result; The clock signal of the tire pressure sensing device is modulated according to the clock correction data so that the frequency of the modulated clock signal reaches the target frequency. The step of obtaining clock correction data based on the determination result includes: If the determination result is that the clock buffer data is consistent with the initial data, then the clock signal frequency of the tire pressure sensing device is obtained, and the clock correction data is generated according to the clock signal frequency; the clock correction data is sent to the tire pressure sensing device to replace the clock buffer data. If the determination result is that the clock buffer data is inconsistent with the initial data, then the clock buffer data shall be used as the clock correction data; The query for clock buffer data corresponding to the operating temperature includes: querying the mapping table of sample temperature ranges and sample clock buffer data stored in the tire pressure sensing device to obtain the clock buffer data.