WO2019119228A1

WO2019119228A1 - Method and apparatus for updating time, and movable platform

Info

Publication number: WO2019119228A1
Application number: PCT/CN2017/117010
Authority: WO
Inventors: 张岩松; 彭夏鹏; 房玲江
Original assignee: 深圳市大疆创新科技有限公司
Priority date: 2017-12-18
Filing date: 2017-12-18
Publication date: 2019-06-27
Also published as: CN109154796B; CN109154796A

Abstract

Embodiments of the present invention provide a method and apparatus for updating time, and a movable platform. The method comprises: obtaining at least two change amounts of a counter within a first preset period; averaging the at least two change amounts; determining the crystal oscillator frequency of the counter on the basis of the averaging result and the first preset period; and updating local time on the basis of the crystal oscillator frequency. The embodiments of the present invention can reduce the complexity of time update and reduce costs while ensuring time update accuracy, without requiring a dedicated hardware circuit.

Description

Time update method, device and mobile platform

Technical field

The present application relates to the field of time calibration technology, and in particular, to a time update method, device, and mobile platform.

Background technique

The Global Navigation Satellite System (GNSS) has been widely used around the world. When GNSS grants time to other devices, other devices typically require proprietary hardware circuitry to calibrate and update local time, which is relatively large in size, weight, complexity, and cost.

Summary of the invention

The embodiment of the invention provides a time update method, a device and a mobile platform, which can reduce the complexity of time update and reduce the cost while ensuring the accuracy of time update.

A first aspect of the embodiments of the present invention provides a time update method, including:

Obtaining a change amount of at least two of the counters in the first preset time;

Performing an averaging process on the at least two variations;

Determining a crystal oscillator frequency of the counter based on a result of the averaging process and the first preset time;

The local time is updated based on the crystal frequency.

A second aspect of the embodiments of the present invention provides a time update method, including:

Obtaining more than two unit time variations of the counter;

Performing an averaging process on two or more unit time variations of the counter to obtain a crystal oscillator frequency of the counter;

The local time is updated based on the crystal frequency.

A third aspect of the embodiments of the present invention provides a time update apparatus, including:

One or more processors; the one or more processors operating alone or in concert;

The processor is configured to: acquire at least two changes of the counter in a first preset time; perform averaging processing on the at least two changes; and obtain a result and a solution based on the averaging process Determining a crystal frequency of the counter for a first preset time; updating a local time based on the crystal frequency.

A fourth aspect of the embodiments of the present invention provides a time update apparatus, including:

The processor is configured to: acquire two or more unit time change amounts of the counter; perform averaging processing on two or more unit time change amounts of the counter to obtain a crystal oscillator frequency of the counter; and based on the crystal oscillator frequency, Update local time.

A fifth aspect of the present invention provides a mobile platform, comprising: the time update device according to the above third aspect or the fourth aspect.

A sixth aspect of the embodiments of the present invention provides a computer readable storage medium comprising instructions for performing the time update method of the first aspect or the second aspect when the instructions are executed.

The time update method, the processor, and the mobile platform provided by the embodiment of the present invention obtain the change amount of at least two of the counters in the first preset time, and perform averaging processing on the acquired at least two change amounts, The crystal frequency of the counter is determined based on the result of the averaging and the first preset time, thereby updating the local time according to the determined crystal frequency. In the embodiment of the present invention, by averaging the obtained at least two two variation amounts, and determining the crystal frequency of the counter according to the result of the averaging process and the first preset time, the individual crystal oscillators can be isolated. The difference, as well as the effect of temperature on the crystal frequency, guarantees the accuracy and real-time performance of the timer crystal frequency, so that accurate local time can be obtained when the local time is updated according to the crystal frequency, and no special hardware circuit is needed, saving The space required to install the hardware circuit reduces the cost.

DRAWINGS

FIG. 1 is a schematic diagram of a scenario according to an embodiment of the present disclosure;

2 is a flowchart of a time update method according to an embodiment of the present invention;

FIG. 3 is a flowchart of a method for executing step 204 according to an embodiment of the present invention;

4 is a flowchart of a method for updating a time accumulation error according to an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a time update apparatus according to an embodiment of the present invention; FIG.

FIG. 6 is a schematic structural diagram of a mobile platform according to an embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly described with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

It should be noted that when a component is referred to as being "fixed" to another component, it can be directly on the other component or the component can be present. When a component is considered to "connect" another component, it can be directly connected to another component or possibly a central component. The features of the embodiments and examples described below can be combined with each other without conflict.

All technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined. The terminology used in the description of the present invention is for the purpose of describing particular embodiments and is not intended to limit the invention. The term "and/or" used herein includes any and all combinations of one or more of the associated listed items.

Some embodiments of the present invention are described in detail below with reference to the accompanying drawings. The features of the embodiments and examples described below can be combined with each other without conflict.

FIG. 1 is a schematic diagram of a scenario according to an embodiment of the present invention. FIG. 1 includes a satellite 10, a satellite receiver 11 and a device 12 for receiving timing. The satellite receiver 11 in the embodiment is installed on the device 12 for receiving time. However, it is not limited to being mounted on the device 12. In fact, the satellite receiver 11 and the device 12 can be provided as two separate entities, respectively. The device 12 in this embodiment may be specifically a drone, a car or other movable platform. When the satellite 10 grants time, the satellite 10 generates a Pulse Per Second (PPS) signal, and the rising edge of the PPS signal is transmitted through a communication link (such as a serial port or a bus, but not limited to a serial port or a bus). The falling edge is sent out corresponding to World Standard Time (UTC). After receiving the PPS signal of the satellite 10 and the corresponding UTC, the satellite receiver 11 introduces the PPS signal into the external terminal of the device 12, and the second preset time after the introduction of the PPS signal, the communication link The UTC corresponding to the PPS signal is sent to the device 12, and the device 12 responds to the event that the satellite receiver 11 outputs the PPS signal in the form of an interrupt. Further, after receiving the UTC, the device 12 performs initialization processing on the local time, updates the local time to UTC, and acquires at least two acquired values by acquiring the change amount of the at least two counters in the first preset time. The averaging result of the change amount and the first preset time to determine the crystal frequency of the counter, based on the crystal frequency, The local time is updated so that accurate local time can be obtained without the need for dedicated hardware circuitry, thereby saving space in the device 12, reducing the weight of the device 12, and reducing costs.

Specifically, FIG. 2 is a flowchart of a time update method according to an embodiment of the present invention. The method may be performed by a time update device, which may be specifically a processor with computing and processing capabilities, or UAV, car and other mobile platforms. As shown in FIG. 2, the method includes the following steps:

Step 201: Acquire at least two changes of the counter in a first preset time.

In a possible implementation manner, the three or more count values of the counter may be acquired, so that the time interval between the three or more count values including at least two sets of count values is equal to the first preset time, and then And calculating, according to at least two sets of the count values of the obtained three or more count values, the change amount of the at least two first preset time periods. For example, the obtained count value is a, b, c, wherein the time interval between a and b and b and c is equal to the first preset time, and the amount of change of the calculation timer is |a-b| and |c-b|. Of course, this is for illustrative purposes only and is not a limitation of the invention.

In another possible implementation manner, the start count value and the end count value of the counter in the two or more first preset times may be separately acquired, and then based on the counter at the two or more first preset times. The initial count value and the end count value are calculated, and the amount of change in at least two first preset time periods is calculated. For example, suppose that the counter has a count value of a in the first second, a count value of b in the second second, a count value of c in the third second, and a count value of d in the fourth second, at least the counter can be obtained. The following changes in the first preset time are: |ab|, |cb|, |cd|. Of course, this is for illustrative purposes only and is not a limitation of the invention.

Optionally, in order to ensure the accuracy of the obtained amount of change, the embodiment may also obtain the counter value of the counter obtained by acquiring the number of inversion cycles of the counter and combining any one of the two possible implementation manners. To calculate the amount of change in the counter for the first preset time.

Taking the first preset time equal to 1 second as an example, assume that the count value of the counter at the first second is counter(n-1), the count value at the second second is counter(n), and the number of flip cycles of the counter is T_counter, you can calculate the delta(n) of the counter in 1 second according to the following expression:

Delta(n)=[counter(n)-counter(n-1)+T_counter]%T_counter

Of course, this is for illustrative purposes only and is not a limitation of the invention.

Optionally, in this embodiment, the first preset time may refer to a unified time value, such as 1 second, but is not limited to 1 second. It can also refer to a plurality of different time values. For example, 1 second, 2 seconds, 3 seconds, etc. can be collectively referred to as a first preset time according to the setting. Of course, this is for illustrative purposes only and is not a limitation of the invention.

In this embodiment, two or more unit time changes of the counter are directly acquired, for example, the amount of change of the counter in the first second, the amount of change in the second second, the amount of change in the third second, etc., of course, only examples The description is not intended to be a limitation of the invention.

Step 202: Perform averaging processing on the at least two changes.

In the first possible average processing mode, all the obtained changes can be directly averaged.

In a second possible implementation manner, when the number of the first preset time changes is greater than two, the maximum value and/or the minimum value may be removed from all the obtained changes. The averaging process is performed on the amount of change remaining to remove the maximum value and/or the minimum value.

According to the above example, it is assumed that the acquired counter has a larger amount of change in the first preset time (1 second in the above example) than the preset number of samples filter_num, and the obtained change amount can be obtained by the following filtering algorithm. Perform average filtering to obtain average results

Delta_min=Min{delta(n-filter_num+1)...delta(n)}

Delta_max=Max{delta(n-filter_num+1)...delta(n)}

The filter_num can take any value in the range of 6-8, but is not limited to 6-8. In fact, the value of the filter_num can be set as needed, which is not limited in this embodiment. In this embodiment, setting the value range of the filter_num to 6 to 8 can prevent the filter_num from being set too much, so that the interference cannot be eliminated, or the setting is too large, resulting in unresponsiveness and rapid response to temperature changes. It should be noted here that when the first preset time is 1 second, that is, unit time, the above obtained

That is, the crystal frequency of the counter obtained. If the first preset time is not the unit time, further basis is needed.

And determining the crystal frequency of the counter with the first preset time.

Of course, the above examples are merely illustrative of the second possible implementation described above, and are not intended to be limiting of the invention.

In a third possible implementation, the target change amount whose value is within the first preset range may be extracted from the obtained at least two change amounts to remove the abnormal value from all the acquired change amounts. . Further, all the target change amounts obtained by the extraction are averaged.

Step 203: Determine a crystal oscillator frequency of the counter based on a result of the averaging process and the first preset time.

When the first preset time refers to a preset unified time value, the average change amount obtained by the averaging process may be divided by the first preset time to obtain the crystal frequency of the counter.

When the first preset time refers to a preset plurality of time lengths, the average time length may be obtained by averaging the first preset time corresponding to all the acquired changes, and then using the foregoing Calculate the average change obtained by dividing the average time length to obtain the crystal frequency of the counter.

Step 204: Update the local time based on the crystal frequency.

Optionally, in this embodiment, the local time may be periodically updated according to a preset period, where the preset period may be any value. For example, in an actual scenario, the preset threshold may be set to be smaller than the number of flipping periods of the counter. Any value of the ratio of the crystal frequency of the counter to avoid time loss due to counter overflow.

Optionally, FIG. 3 is a flowchart of a method for performing step 204 according to an embodiment of the present invention. As shown in FIG. 3, the method includes:

Step 301: Acquire a change amount of the counter from a local time initialization time to a current time instant.

In a possible implementation manner, the counter value of the counter at the local time initialization time may be directly subtracted from the counter value of the current time by the counter, and the amount of change of the counter from the local time initialization time to the current time instant may be obtained.

In another possible implementation manner, based on the number of flipping periods of the counter, and the counter value of the counter at the local time initialization time and the current time count value, the change of the counter from the local time initialization time to the current time can be calculated. the amount. For the specific implementation method, refer to the example in step 201 for solving the change amount of the counter within 1 second, and details are not described herein again.

Step 302: Determine a deviation time based on the amount of change of the counter during the time and the crystal frequency of the counter.

For example, the deviation time delta_s can be obtained by the following expression calculation:

Delta_s=delta_counter/freq

Among them, delta_counter is the amount of change of the counter from the local time initialization time to the current time, and freq is the crystal frequency of the counter. Of course, the calculation of the deviation time in the actual scenario may not be limited to the method of the above example, and other customized methods may be adopted as needed.

Step 303: Correct the local time based on the deviation time to obtain the current time.

Optionally, in a possible implementation manner, the local time can be directly modified by using the following expression to obtain the current time:

Local_now=local_time+delta_s

Where local_now is the time of the current time obtained after the correction, and local_time is the local time before the correction. Of course, this is merely an illustration and not a limitation of the invention.

In another possible implementation manner, the local time can be corrected based on the deviation time and the predetermined time cumulative error, and the accurate time of the current time is obtained. For example, in this manner, the expression of the current time and time is solved. The formula can be expressed as follows:

Local_now=local_time+delta_s+T_error_filter

Where T_error_filter is a predetermined time cumulative error.

Optionally, in this embodiment, after the time update device receives the UTC, the time accumulation error involved in the foregoing method may also be updated based on the received UTC and the local time when the UTC is received. In this case, the time accumulation error may be updated once the UTC is received, or the local time accumulation error may be updated every time a preset number of UTCs are received according to a preset strategy.

For example, a time accumulation error is updated every time a preset number of UTCs are received. FIG. 4 is a flowchart of a method for updating a time accumulation error according to an embodiment of the present invention. As shown in FIG. 4, the method for updating the time accumulation error includes :

Step 401: Calculate a local time accumulation error every time a UTC is received.

For example, the local time cumulative error can be calculated according to the following expression:

T_error=UTC-local_time

Where local_time is the local time when UTC is received, and T_error is the local accumulated error when UTC is received.

Optionally, if the absolute value of the time cumulative error obtained by the calculation is less than the first preset threshold when the UTC is received, determining that the local cumulative time error corresponding to the current UTC is a preset value (eg, “ 0" but not limited to 0), and update the local time cumulative error to a preset value.

If the absolute value of the time cumulative error obtained by the calculation is greater than or equal to the first preset threshold when the UTC is received, it is determined that the local cumulative time error corresponding to the UTC received this time is equal to the cumulative error of the time before the UTC is received. .

If the absolute value of the time cumulative error obtained by the calculation is greater than the second preset threshold when the UTC is received, determining the current local time cumulative error based on the association between the preset time cumulative error and the second preset threshold And update the local time cumulative error to determine the cumulative time error obtained. The relationship between the time accumulated error and the second preset threshold may be expressed as:

T_error_now=sign(T_error) ^* limit

Where T_error_now is the current local cumulative error, T_error is the cumulative time error before receiving UTC, and limit is the second preset threshold (such as 1 second, but not limited to 1 second), and sign() is the symbol. The positive number is 1 and the negative number is -1.

If the absolute value of the time cumulative error obtained by the calculation is less than or equal to the second preset threshold when the UTC is received, it is determined that the local cumulative time error corresponding to the UTC received this time is equal to the cumulative error of the time before the UTC is received. .

Step 402: After receiving the preset number of UTCs, performing a median filtering process on the calculated preset number of time cumulative errors to obtain a median value of the preset number of time accumulated errors.

By way of example, assume that the local time cumulative error is updated after receiving three UTCs, where the calculated time cumulative error is T_error ₁ when the first UTC is received and the calculated time when the second UTC is received The cumulative error is T_error _2. When the third UTC is received, the calculated time cumulative error is T_error ₃ , and the median time cumulative error obtained after the median filtering process is: T_error_filter=Mid{T_error ₁ T_error ₂ T_error ₃ } _.

Of course, although the median filtering method used in this embodiment obtains and updates the local time accumulation error, the actual method is not limited to the median filtering method. In fact, it is also possible to obtain a preset number of time cumulative errors. After that, the local time accumulation error is determined according to the method of averaging.

Step 403: Update the local time accumulation error to the median value.

The time update method provided in this embodiment can provide a higher precision time for a longer period of time and improve the reliability of time update even if the time update device fails to receive the PPS signal and UTC for any reason, and the implementation is improved. In the example, by determining and updating the local time accumulation error after receiving the UTC, the time accumulation error is taken as a consideration of the time update, which can eliminate the error caused by the accumulation over time and improve the accuracy of the time update.

Optionally, in this embodiment, two or more unit time variations of the counter are directly obtained by averaging two or more unit time changes of the counter to obtain a crystal frequency of the counter; and updating based on the crystal frequency local time. The specific implementation process is similar to the foregoing method embodiment, and details are not described herein again.

The time update method, the processor, and the mobile platform provided by the embodiment obtain the change amount of the at least two counters in the first preset time, and perform averaging processing on the acquired at least two change amounts, The average result and the first preset time determine the crystal frequency of the counter, thereby updating the local time based on the determined crystal frequency. In this embodiment, by averaging the acquired at least two two variations, and determining the crystal frequency of the counter according to the result of the averaging process and the first preset time, the difference of the individual crystal oscillators can be isolated. And the effect of temperature on the crystal frequency, ensuring the accuracy and real-time of the timer crystal frequency, so that accurate local time can be obtained when the local time is updated according to the crystal frequency, and no special hardware circuit is needed, which saves installation. The space required by the hardware circuit reduces the cost.

FIG. 5 is a schematic structural diagram of a time update apparatus according to an embodiment of the present invention. The time update apparatus may be installed on any device having a timekeeping and time update function, and may be installed on a mobile platform such as a drone. As shown in FIG. 5, the time update device 50 includes: one or more processors 51; the one or more processors work alone or in cooperation; the processor is configured to: acquire at least two of the counters in the first pre- Setting an amount of change in the time; averaging the at least two changes; determining a crystal frequency of the counter based on the result of the averaging process and the first preset time; based on the crystal frequency , update local time.

Optionally, the processor 51 is configured to: acquire three or more count values of the counter, where the three or more count values include a time interval between the at least two sets of count values as a first preset time, based on The at least two sets of the count values of the three or more count values are calculated and obtained to There are two changes in the first preset time.

Optionally, the processor is configured to: respectively acquire a start count value and a stop count value of the counter in two or more first preset times; and based on the counter in the two or more first preset times The start count value and the end count value are calculated to obtain the amount of change in at least two first preset time periods.

Optionally, the processor 51 is configured to: obtain a number of inversion cycles of the counter, based on a start count value and a stop count value of the counter in the two or more first preset times, and The number of inversion cycles of the counter is calculated, and the amount of change in at least two first preset time periods is calculated.

Optionally, the processor 51 is configured to: when the acquired quantity of the first preset time is greater than two, remove the maximum value of the acquired first preset time And/or the minimum value, the averaging process is performed on the amount of change of the first preset time remaining after the maximum value and/or the minimum value are removed.

Optionally, the processor 51 is configured to: perform averaging processing on the acquired target change amount in the at least two change amounts, where the target change amount is a value within a first preset range The amount of change.

Optionally, the processor 51 is configured to: perform initialization processing on the local time.

Optionally, the processor 51 is configured to: receive, according to a second preset time after receiving the second pulse PPS signal, a world standard time UTC sent by the sending device, where the UTC corresponds to a rising edge or a falling edge of the PPS signal. At the moment, the local time is updated to the UTC.

Optionally, the processor 51 is configured to: acquire an amount of change of the counter from a local time initialization time to a current time, based on the amount of change of the counter in the time and the crystal oscillator of the counter The frequency, the deviation time is determined, and the local time is corrected based on the deviation time to obtain the current time.

Optionally, the processor 51 is configured to: obtain, according to the number of inversion cycles of the counter, the count value of the counter at the local time initialization time and the current time count value, and obtain the initialization time of the counter at the local time. The amount of change to the current time.

Optionally, the processor 51 is configured to: correct the local time based on the deviation time and a predetermined time accumulation error, and obtain the current time.

Optionally, the processor 51 is configured to: after receiving the UTC, based on the UTC The local time accumulation error is updated with the local time when the UTC is received.

Optionally, the processor 51 is configured to: update the local time accumulation error every time a preset number of UTCs are received.

Optionally, the processor 51 is configured to: calculate a local time cumulative error every time a UTC is received, and perform a median value of the calculated preset amount of time cumulative error after receiving the preset number of UTCs. The filtering process obtains a median value of the preset number of time accumulation errors, and updates the local time cumulative error to the median value.

Optionally, the processor 51 is configured to: when the UTC is received, if the absolute value of the difference between the UTC and the local time when the UTC is received is less than a first preset threshold, determine the UTC corresponding The accumulated time error is equal to the preset value; if the absolute value of the difference between the UTC and the local time when the UTC is received is greater than or equal to the first preset threshold, the cumulative error of the time corresponding to the UTC is equal to the received The cumulative error before the UTC.

Optionally, the processor 51 is configured to: when receiving the UTC, if the absolute value of the difference between the UTC and the local time when the UTC is received is greater than a second preset threshold, based on the preset time Determining, by the relationship between the cumulative error and the second preset threshold, a time cumulative error corresponding to the UTC; if the absolute value of the difference between the UTC and the local time when the UTC is received is less than or equal to the The second preset threshold, then the time cumulative error corresponding to the UTC is equal to the time cumulative error before receiving the UTC.

Optionally, the processor 51 is configured to: update a local time based on a preset period, where the preset period is smaller than a ratio of a number of inversion cycles of the counter to a crystal oscillator frequency of the counter.

The time update device provided in this embodiment can be used to perform the technical solution of the foregoing method embodiment, and the execution manner and the beneficial effect are similar, and details are not described herein again.

The present invention also provides a time update device comprising one or more processors; the one or more processors operating alone or in cooperation;

FIG. 6 is a schematic structural diagram of a mobile platform according to an embodiment of the present invention. As shown in FIG. 6, the mobile platform 60 includes a time update device 50 as described in the foregoing embodiment.

The embodiment of the invention further provides a computer readable storage medium, comprising instructions for executing the time update method of the above embodiment when the instruction is executed.

In the several embodiments provided by the present invention, it should be understood that the disclosed apparatus and method may be implemented in other manners. For example, the device embodiments described above are merely illustrative. For example, the division of the unit is only a logical function division. In actual implementation, there may be another division manner, for example, multiple units or components may be combined or Can be integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interface, device or unit, and may be in an electrical, mechanical or other form.

The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above integrated unit can be implemented in the form of hardware or in the form of hardware plus software functional units.

The above-described integrated unit implemented in the form of a software functional unit can be stored in a computer readable storage medium. The above software functional unit is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) or a processor to perform the methods of the various embodiments of the present invention. Part of the steps. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, and the like, which can store program codes. .

Those skilled in the art will clearly understand that for the convenience and brevity of the description, only the above The division of each functional module is illustrated. In practical applications, the above function assignment can be completed by different functional modules as needed, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above. For the specific working process of the device described above, refer to the corresponding process in the foregoing method embodiment, and details are not described herein again.

Finally, it should be noted that the above embodiments are merely illustrative of the technical solutions of the present invention, and are not intended to be limiting; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art will understand that The technical solutions described in the foregoing embodiments may be modified, or some or all of the technical features may be equivalently replaced; and the modifications or substitutions do not deviate from the technical solutions of the embodiments of the present invention. range.

Claims

A time update method, comprising:

Obtaining a change amount of at least two of the counters in the first preset time;

Performing an averaging process on the at least two variations;

Determining a crystal oscillator frequency of the counter based on a result of the averaging process and the first preset time;

The local time is updated based on the crystal frequency.
The method according to claim 1, wherein the obtaining the amount of change of the at least two counters in the first preset time comprises:

Obtaining three or more count values of the counter, wherein the three or more count values include a time interval between the at least two sets of count values as a first preset time;

And calculating, according to the at least two sets of the count values of the three or more count values, the change amount of the at least two first preset time periods.
The method according to claim 1, wherein the obtaining the amount of change of the at least two counters in the first preset time comprises:

Obtaining a start count value and a stop count value of the counter in two or more first preset times, respectively;

And calculating, according to the start count value and the end count value of the counter in the two or more first preset times, obtaining the change amount of the at least two first preset times.
The method of claim 3, wherein the method further comprises:

Obtaining the number of flip cycles of the counter;

And calculating, according to the start count value and the end count value of the counter in the two or more first preset times, obtaining the change amount of the at least two first preset times, including:

Calculating the change amount of at least two first preset times based on the start count value and the end count value of the counter in the two or more first preset times, and the number of flip cycles of the counter .
The method according to any one of claims 1 to 4, wherein the averaging processing the change amount of the two or more first preset times comprises:

When the obtained number of changes of the first preset time is greater than two, the maximum value and/or the minimum value of the acquired changes of all the first preset times are removed;

The averaging process is performed on the amount of change of the first preset time remaining after the maximum value and/or the minimum value are removed.
The method according to any one of claims 1 to 4, wherein the averaging processing the at least two variation amounts comprises:

The averaging process is performed on the acquired target change amount of the at least two change amounts, wherein the target change amount is a change amount of the numerical size within the first preset range.
The method according to claim 1, wherein before the obtaining the amount of change of the at least two counters in the first preset time, the method further comprises:

Initialize the local time.
The method according to claim 7, wherein the initializing the local time comprises:

Receiving, in a second preset time after receiving the second pulse PPS signal, a world standard time UTC sent by the transmitting device, where the UTC corresponds to a time of a rising edge or a falling edge of the PPS signal;

Updating the local time to the UTC.
The method according to claim 8, wherein said updating the local time based on said crystal oscillator frequency comprises:

Obtaining a change amount of the counter from a local time initialization time to a current time instant;

Determining a deviation time based on an amount of change of the counter during the time and the crystal frequency of the counter;

Based on the deviation time, the local time is corrected to obtain the current time.
The method according to claim 9, wherein the obtaining the amount of change of the counter from the local time initialization time to the current time time comprises:

The amount of change of the counter from the local time initialization time to the current time is calculated based on the number of inversion cycles of the counter and the count value of the counter at the local time initialization time and the current time count value.
The method according to claim 9 or 10, wherein the correcting the local time based on the deviation time to obtain the time of the current time comprises:

Based on the deviation time and a predetermined time accumulation error, the local time is corrected to obtain the current time.
The method of claim 8 further comprising:

After receiving the UTC, the local time accumulation error is updated based on the UTC and the local time when the UTC was received.
The method according to claim 12, wherein, after receiving the UTC, updating a local time accumulation error based on the UTC and a local time when the UTC is received, including:

The local time accumulation error is updated each time a preset number of UTCs are received.
The method according to claim 13, wherein the updating of the local time accumulation error every time a preset number of UTCs is received comprises:

Calculate a local time cumulative error each time a UTC is received;

After receiving the preset number of UTCs, performing a median filtering process on the calculated preset number of time accumulated errors to obtain a median value of the preset number of time accumulated errors;

The local time cumulative error is updated to the median value.
The method according to claim 14, wherein each time a UTC is received, a local time cumulative error is calculated, including:

When the UTC is received, if the absolute value of the difference between the UTC and the local time when the UTC is received is less than the first preset threshold, determining that the time cumulative error corresponding to the UTC is equal to a preset value;

If the absolute value of the difference between the UTC and the local time when the UTC is received is greater than or equal to the first preset threshold, the time cumulative error corresponding to the UTC is equal to the time cumulative error before receiving the UTC.
The method according to claim 14, wherein each time a UTC is received, a local time cumulative error is calculated, including

When receiving the UTC, if the absolute value of the difference between the UTC and the local time when the UTC is received is greater than the second preset threshold, based on the preset time cumulative error and the second preset threshold Correlation relationship, determining a time accumulation error corresponding to the UTC;

If the absolute value of the difference between the UTC and the local time when the UTC is received is less than or equal to the second preset threshold, the time cumulative error corresponding to the UTC is equal to the time cumulative error before receiving the UTC .
Method according to any of the claims 1 to 16, characterized in that the base Updating the local time at the crystal frequency, including:

The local time is updated based on a preset period that is less than a ratio of the number of flip cycles of the counter to the crystal frequency of the counter.
A time update method, comprising:

Obtaining more than two unit time variations of the counter;

Performing an averaging process on two or more unit time variations of the counter to obtain a crystal oscillator frequency of the counter;

The local time is updated based on the crystal frequency.
A time updating apparatus, wherein when the apparatus includes a processor, the processor is configured to: acquire at least two changes of a counter in a first preset time; for the at least two The amount of change is averaged; based on the result of the averaging process and the first preset time, the crystal frequency of the counter is determined; and the local time is updated based on the crystal frequency.
The time updating apparatus according to claim 19, wherein said processor is configured to: acquire three or more count values of a counter, wherein said three or more count values include a time between at least two sets of count values The interval is a first preset time, and based on the at least two sets of the count values of the three or more count values, calculating the change amount of the at least two first preset time periods.
The time update device according to claim 19, wherein the processor is configured to: respectively acquire a start count value and a stop count value of the counter in two or more first preset times; The start count value and the end count value of the two or more first preset times are calculated to obtain the change amount of the at least two first preset times.
The time update device according to claim 21, wherein the processor is configured to: acquire a number of inversion cycles of the counter, based on a start of the counter in the two or more first preset times The count value and the end count value, and the number of flip cycles of the counter, are calculated to obtain the amount of change for at least two first preset times.
The time update device according to any one of claims 19 to 22, wherein the processor is configured to: remove the acquired when the obtained number of changes of the first preset time is greater than two The maximum value and/or the minimum value of all the first preset time changes, and the averaging of the remaining first preset time after removing the maximum value and/or the minimum value Reason.
The time update device according to any one of claims 19 to 22, wherein the processor is configured to: perform averaging processing on the target change amount of the acquired at least two change amounts, wherein The target change amount is a change amount of the numerical value within the first preset range.
The time updating apparatus according to claim 19, wherein said processor is configured to: perform initialization processing on the local time.
The time update device according to claim 25, wherein the processor is configured to: receive a world standard time UTC sent by the transmitting device in a second preset time after receiving the second pulse PPS signal, where the UTC corresponds to The local time is updated to the UTC at the time of the rising or falling edge of the PPS signal.
The time updating apparatus according to claim 26, wherein said processor is configured to: acquire a change amount of said counter from a local time initialization time to a current time, based on a change of said counter within said time The amount and the crystal frequency of the counter determine the deviation time, and based on the deviation time, the local time is corrected to obtain the current time.
The time updating apparatus according to claim 27, wherein said processor is configured to: calculate based on a number of inversion cycles of said counter, and a count value of said counter at a local time initialization time and a current time count value Obtaining the amount of change of the counter from the local time initialization time to the current time.
The time updating apparatus according to claim 27 or 28, wherein the processor is configured to: correct the local time based on the deviation time and a predetermined time accumulation error to obtain a time of the current time.
The time updating apparatus according to claim 26, wherein said processor is configured to: after receiving said UTC, update a local time cumulative error based on said UTC and a local time when said UTC is received .
The time updating apparatus according to claim 30, wherein said processor is configured to: update a local time accumulation error every time a preset number of UTCs are received.
The time updating apparatus according to claim 31, wherein said processor is configured to: calculate a local time cumulative error every time a UTC is received, and obtain a pre-calculated prediction after receiving a preset number of UTCs Set the amount of time cumulative error for median filtering And obtaining a median value of the preset number of time accumulation errors, and updating the local time accumulation error to the median value.
The time update device according to claim 32, wherein the processor is configured to: when receiving the UTC, if the absolute value of the difference between the UTC and the local time when the UTC is received is smaller than the first pre- Setting a threshold, determining that the time cumulative error corresponding to the UTC is equal to a preset value; if the absolute value of the difference between the UTC and the local time when the UTC is received is greater than or equal to a first preset threshold, the UTC The corresponding time cumulative error is equal to the time cumulative error before the UTC is received.
The time update apparatus according to claim 32, wherein the processor is configured to: when receiving the UTC, if the absolute value of the difference between the UTC and the local time when the UTC is received is greater than the second pre- Setting a threshold, determining a time cumulative error corresponding to the UTC based on a relationship between a preset time cumulative error and the second preset threshold; if the UTC is related to a local time when the UTC is received The difference absolute value is less than or equal to the second preset threshold, and the time cumulative error corresponding to the UTC is equal to the time cumulative error before receiving the UTC.
The time updating apparatus according to any one of claims 19 to 34, wherein the processor is configured to: update a local time based on a preset period, the preset period being less than a number of flipping cycles of the counter The ratio of the crystal frequency of the counter.
A time update device, comprising: one or more processors; the one or more processors operating separately or in cooperation;

The processor is configured to: acquire two or more unit time change amounts of the counter; perform averaging processing on two or more unit time change amounts of the counter to obtain a crystal oscillator frequency of the counter; and based on the crystal oscillator frequency, Update local time.
A mobile platform, comprising: the time update device according to any one of claims 19-36.
A computer readable storage medium comprising instructions for performing the time update method of any of claims 1-18 when the instructions are run.