CN112383675A - Time synchronization method and device and terminal equipment - Google Patents
Time synchronization method and device and terminal equipment Download PDFInfo
- Publication number
- CN112383675A CN112383675A CN202011280783.5A CN202011280783A CN112383675A CN 112383675 A CN112383675 A CN 112383675A CN 202011280783 A CN202011280783 A CN 202011280783A CN 112383675 A CN112383675 A CN 112383675A
- Authority
- CN
- China
- Prior art keywords
- time
- signal
- data
- camera
- gps
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N5/00—Details of television systems
- H04N5/04—Synchronising
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Electric Clocks (AREA)
- Studio Devices (AREA)
Abstract
The invention discloses a time synchronization method, a time synchronization device and terminal equipment, wherein the method comprises the following steps: the POS positioning and orientation system obtains GPS time service data output by a GPS and sends the GPS time service data to the onboard computer, and then the onboard computer receives and analyzes the GPS time service data to obtain a time signal and a second pulse signal output by the GPS; and then introducing the time signal and the pulse per second signal into a synchronous controller, and carrying out time synchronization on the synchronous controller to obtain time synchronization data. The invention realizes the synchronous recording of the data of each sensor through the time service type GPS, the pulse per second signal and the synchronous controller, completes the synchronous data acquisition while determining the time reference with high precision, lightens the task load of the onboard industrial control computer and ensures the robustness of the system.
Description
Technical Field
The present invention relates to the field of time synchronization technologies, and in particular, to a time synchronization method, an apparatus, and a terminal device.
Background
Sensors are often used for intelligent routing inspection in an electric power system, but a plurality of sensors often have non-uniform time precision and are easy to generate errors. The traditional data acquisition method with independent control of multiple sensors has few applications, and particularly realizes unification of time and space references of data acquisition of the multiple sensors. For example, in the conventional time synchronization method, for example, chinese patent publication No. CN110599570A and publication No. 2019.12.20, map generation method and system based on crowd-sourced data open scene, time synchronization is performed between the extracted semantic information and the gps track information by using the ID and the timestamp of the vehicle. However, such methods are also not suitable for multi-data source systems composed of an ultraviolet camera, a laser scanner, a visible light camera, and a thermal infrared imager, and cannot ensure that each multi-data source system establishes high precision and uniform time synchronization.
Disclosure of Invention
The invention provides a time synchronization method, a time synchronization device and terminal equipment. The invention is suitable for multi-data source systems composed of an ultraviolet camera, a laser scanner, a visible light camera, a thermal infrared imager and the like, and ensures that each multi-data source system establishes high precision and unified time synchronization.
The specific technical scheme is as follows:
a method of time synchronization, comprising:
the POS positioning and orientation system obtains GPS time service data output by a GPS and sends the GPS time service data to the onboard computer, and then the onboard computer receives and analyzes the GPS time service data to obtain a time signal and a second pulse signal output by the GPS; then, introducing the time signal and the pulse per second signal into a synchronous controller, and carrying out time synchronization on the synchronous controller to obtain time synchronization data; the pulse per second signal is a PPS signal; the time synchronization data comprises time information and a corresponding pulse per second signal;
the synchronous controller simultaneously sends time synchronization data after time service to the ultraviolet camera, the laser scanner, the visible light camera and the thermal infrared imager; meanwhile, after the ultraviolet camera, the laser scanner, the visible light camera and the thermal infrared imager respectively receive the pulse per second signal, the second counting is cleared;
the synchronous controller triggers the ultraviolet camera in a hard triggering mode, sends the exposure time of the ultraviolet camera to an onboard computer for recording, and takes the exposure time in the acquired image information as the initial exposure time so as to perform time identification on the image information shot by the ultraviolet camera in the following process; the synchronous controller simultaneously utilizes the API interface to trigger the exposure time of the visible light camera in a soft triggering mode so as to obtain the same exposure time as that of the ultraviolet camera and take the exposure time as the initial exposure time, so that the subsequent time identification is carried out on the image information shot by the visible light camera;
after the time reference is unified, presetting high-frequency in a POS positioning and orientation system, acquiring spatial position and attitude data corresponding to each frame data acquisition time in original data acquired by a multi-data-source system consisting of an ultraviolet camera, a laser scanner, a visible light camera and a thermal infrared imager, and then realizing the spatial reference calibration unified operation of each frame data of the multi-data-source system by using a reference object.
Preferably, as one possible embodiment; the airborne computer comprises a GPS time service receiving module which is a GPS time service receiver.
Preferably, as one possible embodiment; the preset high-frequency range of the POS positioning and orientation system is 100-200 Hz.
Preferably, as one possible embodiment; before the synchronous controller simultaneously sends time synchronization data after time service to the ultraviolet camera, the laser scanner, the visible light camera and the thermal infrared imager, the ground assistance system utilizes the Beidou satellite time service signal to carry out further time calibration early warning operation on the time information in the current time synchronization data.
Preferably, as one possible embodiment; the method comprises the following steps of utilizing a Beidou satellite time service signal through a ground assistance system to implement further time calibration early warning operation on time information in current time synchronization data, and specifically comprising the following operation steps:
the ground assisting system receives a downlink signal from Beidou satellite time service through a Beidou satellite time service antenna to obtain an asynchronous serial code stream signal, completes a time stamp generation process on the asynchronous serial code stream signal, and then analyzes time information in the time stamp to serve as reference time information for calibration;
transmitting the reference time information to the synchronous controller;
the synchronous controller subtracts the time value from the time information recorded by the reference time information and the time synchronization data to obtain a time delay measurement value; and judging the relation between the time delay measurement value and a preset standard time delay measurement value, if the time delay measurement value is greater than the standard time delay measurement value, judging that the time information error in the current time synchronization data exceeds the limit, and prompting early warning information.
Preferably, as one possible embodiment; after the ultraviolet camera, the laser scanner, the visible light camera and the thermal infrared imager respectively receive the second pulse signals, the second counting is cleared, so that time information accurate to the microsecond is obtained, meanwhile, the ultraviolet camera and the visible light camera also receive local clock signals from a ground assistance system as detection frame pulse signals, and the operation step of remotely calibrating the local clocks is realized; the ground assistance system comprises a ground assistance server.
Preferably, as one possible embodiment; the steps of remotely calibrating the local clock are as follows:
receiving a pulse per second signal of a GPS, and performing frequency multiplication operation on the pulse per second signal of the GPS according to a signal frame period to generate a frame synchronization sequence signal to be detected;
receiving a local clock signal from a ground assistance system as a preliminary detection frame pulse signal;
carrying out frequency multiplication operation on the prepared detection frame pulse signal to generate a detection frame pulse signal;
obtaining the clock deviation between a local clock signal and a second pulse signal of the GPS according to the deviation between the clock analyzed by the frame synchronization sequence signal to be detected and the clock analyzed by the detection frame pulse signal;
and calibrating the local clock according to the clock deviation.
Preferably, as one possible embodiment; the synchronous controller triggers the ultraviolet camera in a hard triggering mode, and specifically comprises the following operation steps:
the ultraviolet camera receives the hard trigger of the synchronous controller, and then sends a Strobe signal to the synchronous controller;
the synchronous controller simultaneously utilizes an API interface to trigger the exposure time of the visible light camera in a soft triggering mode so as to obtain the same exposure time as that of the ultraviolet camera, and the method specifically comprises the following operation steps:
the synchronous controller analyzes the time moment in the Strobe signal of the external trigger signal, obtains the time difference between the emission and the exposure of the Strobe signal of the ultraviolet camera, and obtains the first exposure time of the ultraviolet camera by using the time moment in the Strobe signal of the external trigger signal and the time difference between the emission and the exposure of the Strobe signal; wherein the time difference between Strobe signaling and exposure is a first time difference pertaining to the ultraviolet camera;
and directly calling a second time difference from the soft triggering of the visible light camera to the exposure time by utilizing an API (application program interface) interface of the synchronous controller, calculating to obtain the soft triggering time required by the soft triggering of the ultraviolet camera, and sending the soft triggering time to the visible light camera for soft triggering by the API interface of the synchronous controller after the synchronous controller detects that the current time reaches the time of the soft triggering time, so as to ensure that the visible light camera is exposed at the first exposure time after soft triggering.
Correspondingly, the invention also provides a time synchronization device, which comprises a POS positioning and orientation system, an airborne computer and a synchronization controller, wherein the POS positioning and orientation system comprises a GPS; the POS positioning and orientation system is electrically connected with the airborne computer, and the airborne computer is also electrically connected with the synchronous controller; the synchronous controller is simultaneously electrically connected with the ultraviolet camera, the laser scanner, the visible light camera and the thermal infrared imager.
The present invention also provides a terminal device, including: a processor and a memory, the memory storing a computer program, the processor for executing the computer program to implement the multi-sensor based time synchronization method described above.
The technical scheme of the invention has the following beneficial effects:
the multi-sensor-based time synchronization method provided by the invention is different from the traditional multi-sensor independent control data acquisition method, the multi-sensor synchronization control method provided by the invention can realize the unification of the time and the space reference of the multi-sensor data acquisition, and each data frame of the acquired laser point cloud data, optical image data, infrared video data and ultraviolet image data is synchronous observation data, so that a data basis is laid for the diagnosis of the fault realized by the multi-source data contrast analysis. The invention realizes the synchronous recording of the data of each sensor through the time service type GPS, the pulse per second signal and the synchronous controller, completes the synchronous data acquisition while determining the time reference with high precision, lightens the task load of the onboard industrial control computer and ensures the robustness of the system.
The invention also realizes high-precision synchronous triggering by combining an improved camera triggering mode with a pulse per second signal, thereby ensuring the subsequent execution effect of time synchronization.
Drawings
FIG. 1 is a schematic flow chart of a time synchronization method according to the present invention;
FIG. 2 is a schematic flow chart illustrating a further time alignment pre-warning operation performed on time information in current time synchronization data;
FIG. 3 is a flowchart illustrating the operation steps of remotely calibrating a local clock;
FIG. 4 is a schematic flow chart illustrating the hard triggering of the ultraviolet camera and the soft triggering of the visible light camera according to the present invention;
fig. 5 is a schematic structural diagram of a time synchronization apparatus according to the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.
The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.
Hereinafter, the terms "including", "having", and their derivatives, which may be used in various embodiments of the present invention, are only intended to indicate specific features, numbers, steps, operations, elements, components, or combinations of the foregoing, and should not be construed as first excluding the existence of, or adding to, one or more other features, numbers, steps, operations, elements, components, or combinations of the foregoing.
Furthermore, the terms "first," "second," "third," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which various embodiments of the present invention belong. The terms (such as those defined in commonly used dictionaries) should be interpreted as having a meaning that is consistent with their contextual meaning in the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein in various embodiments of the present invention.
Example 1
The embodiment provides a time synchronization method which can be applied to an application platform such as an unmanned aerial vehicle.
The unmanned aerial vehicle multi-sensor data acquisition system used in the embodiment can acquire high-precision airborne laser scanning (Li DAR) point cloud data, high-resolution aviation digital images, thermal infrared images, ultraviolet images and the like in an electric power line corridor. The data acquisition system mainly comprises an ultraviolet camera, a laser scanner, a visible light camera, a thermal infrared imager, a receiver, a Global Positioning System (GPS), a POS (position and orientation system), a flight planning and management system, a data storage system and the like.
The ultraviolet camera, the laser scanner, the visible light camera and the thermal infrared imager are respectively associated with the POS positioning and orienting system, so that the unification of time coordinates of the ultraviolet camera, the laser scanner, the visible light camera and the thermal infrared imager on the machine is realized, and the unification of data time and space reference collected by each sensor is realized.
As shown in fig. 1, a time synchronization method includes the following operation processes:
the POS positioning and orientation system obtains GPS time service data output by a GPS and sends the GPS time service data to the onboard computer, and then the onboard computer receives and analyzes the GPS time service data to obtain a time signal and a second pulse signal output by the GPS; then, introducing the time signal and the pulse per second signal into a synchronous controller, and carrying out time synchronization on the synchronous controller to obtain time synchronization data; wherein, the Pulse Per Second (PPS) is a PPS signal; the time synchronization data comprises time information and a corresponding pulse per second signal;
the synchronous controller simultaneously sends time synchronization data after time service to the ultraviolet camera, the laser scanner, the visible light camera and the thermal infrared imager; meanwhile, after the ultraviolet camera, the laser scanner, the visible light camera and the thermal infrared imager respectively receive the pulse per second signal, the second counting is cleared;
the synchronous controller triggers the ultraviolet camera in a hard triggering mode, sends the exposure time of the ultraviolet camera to an onboard computer for recording, and takes the exposure time in the acquired image information as the initial exposure time so as to perform time identification on the image information shot by the ultraviolet camera in the following process; the synchronous controller simultaneously utilizes the API interface to trigger the exposure time of the visible light camera in a soft triggering mode so as to obtain the same exposure time as that of the ultraviolet camera and take the exposure time as the initial exposure time, so that the subsequent time identification is carried out on the image information shot by the visible light camera; it should be noted that through the above operations, the time of the data of the POS positioning and orientation system, the visible light camera, the laser scanner, the thermal infrared imager, and the ultraviolet camera is the unified GPS time, and the purpose of unifying the time references of multiple data sources is achieved.
After the time reference is unified, presetting high-frequency in a POS positioning and orienting system, acquiring spatial position and attitude data corresponding to each frame data acquisition time in original data acquired by a multi-data-source system consisting of an ultraviolet camera, a laser scanner, a visible light camera and a thermal infrared imager, and then realizing the spatial reference calibration unified operation of each frame data of the multi-data-source system by using a reference object; the spatial position and attitude data corresponding to each frame data acquisition time of each sensor can be obtained from the original data recorded at high frequency (100-200 Hz), and the unification of the spatial reference is completed.
Because the program written by using the high-level language of the computer can not record the time of mu s or ns level with high precision, the invention realizes the synchronous recording of the data of each sensor through the time service type GPS and the synchronous controller, completes the synchronous data acquisition while determining the time reference with high precision, lightens the task load of the airborne industrial control computer and ensures the robustness of the system.
In addition, the POS positioning and orientation system provided by the invention is a time-frequency server with high precision time and high precision frequency, which is developed and designed, and adopts a standard 2U design, and a receiver and a rubidium clock (constant temperature crystal oscillator) can externally output various time-frequency signals such as PTP, NTP, IRIG-B code, 1PPS, 10MHz frequency standard and the like. And a rubidium clock and crystal oscillator mixed mode disciplined frequency mechanism is supported. The POS positioning and orienting system is a comprehensive frequency source with high precision, time keeping, high performance stability and low phase noise. The POS positioning and orienting system is internally provided with a rubidium clock and a bottom phase noise constant-temperature crystal oscillator mixed timekeeping strategy. The signal has the advantages of good long-term stability, no accumulated error, high time synchronism with international standard, low phase noise and better stability.
In this embodiment, the onboard computer includes a GPS time service receiving module, the time service receiving module is a GPS time service receiver, and the preset high-frequency range of the POS positioning and orientation system is 100 to 200 Hz.
In this embodiment, before the synchronization controller sends time synchronization data after time service to the ultraviolet camera, the laser scanner, the visible light camera, and the thermal infrared imager at the same time, the ground assistance system utilizes the beidou satellite time service signal to perform further time calibration and early warning operations on the time information in the current time synchronization data.
As shown in fig. 2, a ground assistance system utilizes a Beidou satellite time service signal to perform further time calibration early warning operation on time information in current time synchronization data, and specifically includes the following operation steps:
the ground assisting system receives a downlink signal from Beidou satellite time service through a Beidou satellite time service antenna to obtain an asynchronous serial code stream signal, completes a time stamp generation process on the asynchronous serial code stream signal, and then analyzes time information in the time stamp to serve as reference time information for calibration;
transmitting the reference time information to the synchronous controller;
the synchronous controller subtracts the time value from the time information recorded by the reference time information and the time synchronization data to obtain a time delay measurement value; and judging the relation between the time delay measurement value and a preset standard time delay measurement value, and if the time delay measurement value is greater than the standard time delay measurement value, judging that the time information error in the current time synchronization data exceeds the limit, and prompting early warning information.
In the embodiment, after the ultraviolet camera, the laser scanner, the visible light camera and the thermal infrared imager respectively receive the second pulse signal, the second counting is cleared, so that the time information accurate to the microsecond is obtained, and meanwhile, the ultraviolet camera and the visible light camera also receive the local clock signal from the ground assistance system as the detection frame pulse signal, so that the operation step of remotely calibrating the local clock is realized; the ground assistance system further comprises a ground assistance server.
As shown in fig. 3, the operation steps of remotely calibrating the local clock are as follows:
receiving a pulse per second signal of a GPS, and performing frequency multiplication operation on the pulse per second signal of the GPS according to a signal frame period to generate a frame synchronization sequence signal to be detected;
receiving a local clock signal from a ground assistance system as a preliminary detection frame pulse signal;
carrying out frequency multiplication operation on the prepared detection frame pulse signal to generate a detection frame pulse signal;
obtaining the clock deviation between a local clock signal and a second pulse signal of the GPS according to the deviation between the clock analyzed by the frame synchronization sequence signal to be detected and the clock analyzed by the detection frame pulse signal;
and calibrating the local clock according to the clock deviation.
It should be noted that, the invention performs multiplying power processing on the GPS second pulse signal by using the frequency multiplication clock, and can generate a frame synchronization sequence signal to be detected after multiplying power operation; meanwhile, a local clock signal from a ground assistance system is received as a prepared detection frame pulse signal, multiplying power processing is carried out in the same way, and then clock deviation between a server local clock signal and a GPS second pulse signal is obtained according to deviation between a clock analyzed by a frame synchronization sequence signal to be detected and a clock analyzed by a detection frame pulse signal; and finally, the local clock can be quickly calibrated according to the clock deviation.
As shown in fig. 4, the synchronous controller triggers the ultraviolet camera in a hard trigger mode, and specifically includes the following operation steps:
the ultraviolet camera receives the hard trigger of the synchronous controller, and then sends a Strobe signal to the synchronous controller;
the synchronous controller simultaneously utilizes an API interface to trigger the exposure time of the visible light camera in a soft triggering mode so as to obtain the same exposure time as that of the ultraviolet camera, and the method specifically comprises the following operation steps:
the synchronous controller analyzes the time moment in the Strobe signal of the external trigger signal, obtains the time difference between the emission and the exposure of the Strobe signal of the ultraviolet camera, and obtains the first exposure time of the ultraviolet camera by using the time moment in the Strobe signal of the external trigger signal and the time difference between the emission and the exposure of the Strobe signal; wherein the time difference between Strobe signaling and exposure is a first time difference pertaining to the ultraviolet camera;
and directly calling a second time difference from the soft triggering of the visible light camera to the exposure time by utilizing an API (application program interface) interface of the synchronous controller, calculating to obtain the soft triggering time required by the soft triggering of the ultraviolet camera, and sending the soft triggering time to the visible light camera for soft triggering by the API interface of the synchronous controller after the synchronous controller detects that the current time reaches the time of the soft triggering time, so as to ensure that the visible light camera is exposed at the first exposure time after soft triggering.
It should be noted that, the problems existing at present are: even if a plurality of cameras receive a calibrated high-precision pulse-per-second signal, the time synchronization of the plurality of cameras requiring higher precision cannot be guaranteed, which is because: the synchronous triggering of the time with higher precision among a plurality of cameras has high requirement on hardware, the cost of the cameras is higher, and the time precision is difficult to guarantee by synchronous hard triggering; the method is implemented by adopting a mode of ultraviolet camera hard triggering and visible light camera soft triggering; the ultraviolet camera receives direct hard trigger operation of the synchronous controller;
wherein, the triggering belongs to an external triggering mode: the camera acquires images through signals given from the outside, and the external trigger signals can be software signals or hardware signals; if a hard triggering mode is adopted, one MCU in the synchronous controller can be used for generating pulse signals to perform hard triggering on the sensor devices of the two cameras, but the mode has higher cost and low synchronous triggering precision. However, in the present embodiment, the triggering of the two cameras is a soft and hard combined triggering method, and there are also many soft and hard combined triggering methods, and the embodiment of the present application adopts an updated triggering method. The ultraviolet camera receives the hard trigger of the synchronous controller, then the ultraviolet camera sends an external trigger signal (Strobe signal) to the synchronous controller, and the synchronous controller analyzes the time moment in the external trigger signal Strobe signal and calculates to obtain an accurate exposure moment (namely a first exposure moment) of the ultraviolet camera; it should be specially noted that the camera trigger output signal is a switch signal, and can be used for controlling other external devices such as a camera, a controller, and the like. The camera receives the trigger and then carries out exposure, and when the exposure of the camera occurs, a Strobe signal is output and is active at a high level. Soft triggering of other cameras can be assisted using the signal as a data source; the Strobe signal is asserted earlier than the exposure time. The working principle is that Strobe signals are output firstly and then delayed exposure is carried out, the first exposure time (namely exposure time) of the ultraviolet camera can be calculated through a synchronous controller by utilizing the function, namely the time in the Strobe signals of the external trigger signals is analyzed and the time difference between the emission and the exposure of the Strobe signals is added (the time difference between the emission and the exposure of the Strobe signals can be defined as the first time difference, research finds that the time difference between the emission and the exposure of the Strobe signals is a fixed value through research verification, and the value is related to the hardware information of the camera, so after the hardware model of the ultraviolet camera is determined, the accurate first exposure time of the ultraviolet camera can be obtained by calculating the time in the Strobe signals of the external trigger signals and the time difference between the emission and the exposure of the Strobe signals.
Then, directly calling a second time difference (which is also a fixed value after the visible light camera is determined and the software application determines) of the visible light camera to be soft-triggered to the first exposure time by using an API (application programming interface) interface of the synchronous controller, so that the soft trigger time required by the ultraviolet camera to be soft-triggered can be calculated, and after the API waiting time of the synchronous controller reaches the time of the soft trigger time, the API of the synchronous controller sends the soft trigger time to the visible light camera for soft triggering, so that the exposure of the visible light camera can be accurately realized at a certain time (namely, the visible light camera is ensured to be exposed at the first exposure time).
In summary, different from a traditional data acquisition method of independent control of multiple sensors, the multi-sensor time synchronization control method provided by the embodiment of the invention can realize unification of time and space reference of multi-sensor data acquisition, and each data frame of acquired laser point cloud data, optical image data, infrared video data and ultraviolet image data is synchronous observation data, so that a data basis is laid for multi-source data comparison and analysis to realize fault diagnosis; and finally, high-precision synchronous triggering is realized by using the camera triggering mode, and the subsequent execution effect of time synchronization is guaranteed.
Example 2
As shown in fig. 5, based on the method of embodiment 1, this embodiment provides a time synchronization apparatus, including: the POS positioning and orientation system comprises a POS positioning and orientation system, an airborne computer and a synchronous controller, wherein the POS positioning and orientation system comprises a GPS; the POS positioning and orientation system is electrically connected with the airborne computer, and the airborne computer is also electrically connected with the synchronous controller; the synchronous controller is simultaneously electrically connected with the ultraviolet camera, the laser scanner, the visible light camera and the thermal infrared imager.
In this embodiment, the system further includes a ground assistance system, and the ground assistance system is electrically connected to the synchronization controller.
It is to be understood that the multi-sensor based time synchronization apparatus described above corresponds to the on-screen display method of the multi-os of embodiment 1. Any of the options in embodiment 1 are also applicable to this embodiment, and will not be described in detail here.
Example 3
The present invention also provides a terminal device, including: a processor and a memory, the memory storing a computer program, the processor for executing the computer program to implement the multi-sensor based time synchronization method of embodiment 1 described above.
The memory may include a storage program area and a storage data area, wherein the storage program area may store an operating system, an application program required for at least one function; the storage data area may store data created according to the use of the terminal, and the like. Further, the memory may include high speed random access memory, and may also include non-volatile memory, such as at least one magnetic disk storage device, flash memory device, or other volatile solid state storage device.
The present invention also provides a computer-readable storage medium for storing the computer program used in the above-mentioned terminal.
In the embodiments provided in the present application, it should be understood that the disclosed apparatus and method can be implemented in other ways. The apparatus embodiments described above are merely illustrative and, for example, the flowchart and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems which perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.
The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention.
Claims (10)
1. A method of time synchronization, comprising:
the POS positioning and orientation system obtains GPS time service data output by a GPS and sends the GPS time service data to the onboard computer, and then the onboard computer receives and analyzes the GPS time service data to obtain a time signal and a second pulse signal output by the GPS; then, introducing the time signal and the pulse per second signal into a synchronous controller, and carrying out time synchronization on the synchronous controller to obtain time synchronization data; the pulse per second signal is a PPS signal; the time synchronization data comprises time information and a corresponding pulse per second signal;
the synchronous controller simultaneously sends time synchronization data after time service to the ultraviolet camera, the laser scanner, the visible light camera and the thermal infrared imager; meanwhile, after the ultraviolet camera, the laser scanner, the visible light camera and the thermal infrared imager respectively receive the pulse per second signal, the second counting is cleared;
the synchronous controller triggers the ultraviolet camera in a hard triggering mode, sends the exposure time of the ultraviolet camera to an onboard computer for recording, and takes the exposure time in the acquired image information as the initial exposure time for the subsequent time identification of the image information shot by the ultraviolet camera; the synchronous controller simultaneously utilizes the API interface to trigger the exposure time of the visible light camera in a soft triggering mode, so that the exposure time same as that of the ultraviolet camera is obtained and is used as the initial exposure time for carrying out time identification on image information shot by the visible light camera subsequently;
after the time reference is unified, presetting high-frequency in a POS positioning and orientation system, acquiring spatial position and attitude data corresponding to each frame data acquisition time in original data acquired by a multi-data-source system consisting of an ultraviolet camera, a laser scanner, a visible light camera and a thermal infrared imager, and then realizing the spatial reference calibration unified operation of each frame data of the multi-data-source system by using a reference object.
2. The time synchronization method of claim 1, wherein the onboard computer comprises a GPS time service receiving module, and the time service receiving module is a GPS time service receiver.
3. The time synchronization method according to claim 1, wherein the predetermined high frequency range of the POS positioning and orientation system is 100-200 Hz.
4. The time synchronization method according to claim 1, wherein before the synchronization controller sends time synchronization data after time service to the ultraviolet camera, the laser scanner, the visible light camera and the thermal infrared imager at the same time, the ground assistance system utilizes the Beidou satellite time service signal to perform further time calibration early warning operation on the time information in the current time synchronization data.
5. The time synchronization method according to claim 4, wherein the ground assistance system utilizes the Beidou satellite time service signal to perform further time calibration early warning operation on the time information in the current time synchronization data, and the method specifically comprises the following operation steps:
the ground assisting system receives a downlink signal from Beidou satellite time service through a Beidou satellite time service antenna to obtain an asynchronous serial code stream signal, completes a time stamp generation process on the asynchronous serial code stream signal, and then analyzes time information in the time stamp to serve as reference time information for calibration;
transmitting the reference time information to the synchronous controller;
the synchronous controller subtracts the time value from the time information recorded by the reference time information and the time synchronization data to obtain a time delay measurement value; and judging the relation between the time delay measurement value and a preset standard time delay measurement value, if the time delay measurement value is greater than the standard time delay measurement value, judging that the time information error in the current time synchronization data exceeds the limit, and prompting early warning information.
6. The time synchronization method according to claim 5, wherein the second counting is cleared after the ultraviolet camera, the laser scanner, the visible light camera and the thermal infrared imager respectively receive the second pulse signal, so as to obtain time information accurate to μ s, and meanwhile, the ultraviolet camera and the visible light camera also receive a local clock signal from the ground assistance system as a detection frame pulse signal, so as to realize the operation step of remotely calibrating the local clock; the ground assistance system comprises a ground assistance server.
7. The method for time synchronization according to claim 6, wherein the step of remotely calibrating the local clock comprises:
receiving a pulse per second signal of a GPS, and performing frequency multiplication operation on the pulse per second signal of the GPS according to a signal frame period to generate a frame synchronization sequence signal to be detected;
receiving a local clock signal from a ground assistance system as a preliminary detection frame pulse signal;
carrying out frequency multiplication operation on the prepared detection frame pulse signal to generate a detection frame pulse signal;
obtaining the clock deviation between a local clock signal and a second pulse signal of the GPS according to the deviation between the clock analyzed by the frame synchronization sequence signal to be detected and the clock analyzed by the detection frame pulse signal;
and calibrating the local clock according to the clock deviation.
8. The time synchronization method according to claim 1, wherein the synchronization controller triggers the ultraviolet camera by a hard trigger mode, and specifically comprises the following operation steps:
the ultraviolet camera receives the hard trigger of the synchronous controller, and then sends a Strobe signal to the synchronous controller;
the synchronous controller simultaneously utilizes an API interface to trigger the exposure time of the visible light camera in a soft triggering mode so as to obtain the same exposure time as that of the ultraviolet camera, and the method specifically comprises the following operation steps:
the synchronous controller analyzes the time moment in the Strobe signal of the external trigger signal, obtains the time difference between the emission and the exposure of the Strobe signal of the ultraviolet camera, and obtains the first exposure time of the ultraviolet camera by using the time moment in the Strobe signal of the external trigger signal and the time difference between the emission and the exposure of the Strobe signal; wherein the time difference between Strobe signaling and exposure is a first time difference pertaining to the ultraviolet camera;
and directly calling a second time difference from the soft triggering of the visible light camera to the exposure time by utilizing an API (application program interface) interface of the synchronous controller, calculating to obtain the soft triggering time required by the soft triggering of the ultraviolet camera, and sending the soft triggering time to the visible light camera for soft triggering by the API interface of the synchronous controller after the synchronous controller detects that the current time reaches the time of the soft triggering time, so as to ensure that the visible light camera is exposed at the first exposure time after soft triggering.
9. A time synchronizer is characterized by comprising a POS positioning and orientation system, an airborne computer and a synchronous controller, wherein the POS positioning and orientation system comprises a GPS; the POS positioning and orientation system is electrically connected with the airborne computer, and the airborne computer is also electrically connected with the synchronous controller; the synchronous controller is simultaneously electrically connected with the ultraviolet camera, the laser scanner, the visible light camera and the thermal infrared imager.
10. A terminal device, comprising: a processor and a memory, the memory storing a computer program, the processor for executing the computer program to implement the time synchronization method according to any one of claims 1 to 8.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011280783.5A CN112383675B (en) | 2020-11-16 | 2020-11-16 | Time synchronization method and device and terminal equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011280783.5A CN112383675B (en) | 2020-11-16 | 2020-11-16 | Time synchronization method and device and terminal equipment |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112383675A true CN112383675A (en) | 2021-02-19 |
| CN112383675B CN112383675B (en) | 2023-04-28 |
Family
ID=74584789
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011280783.5A Active CN112383675B (en) | 2020-11-16 | 2020-11-16 | Time synchronization method and device and terminal equipment |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112383675B (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112821980A (en) * | 2021-04-19 | 2021-05-18 | 杭州康吉森自动化科技有限公司 | Clock synchronization system, method and device for industrial automation system |
| CN113176591A (en) * | 2021-05-19 | 2021-07-27 | 浙江宇视科技有限公司 | Time synchronization method and device of monitoring platform, electronic equipment and storage medium |
| CN114220255A (en) * | 2021-12-29 | 2022-03-22 | 宜昌测试技术研究所 | Distributed acoustic equipment synchronous control system and method |
| CN114755693A (en) * | 2022-06-15 | 2022-07-15 | 天津大学四川创新研究院 | Infrastructure facility measuring system and method based on multi-rotor unmanned aerial vehicle |
| CN114812673A (en) * | 2022-04-02 | 2022-07-29 | 北京卫星环境工程研究所 | Multi-parameter multi-module optical fiber data synchronous testing method |
| CN116600211A (en) * | 2023-06-09 | 2023-08-15 | 苏州洞悉科技有限公司 | Imaging system |
| CN117713982A (en) * | 2024-02-04 | 2024-03-15 | 合肥国家实验室 | Method and system for improving time synchronization precision of space laser communication |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103279058A (en) * | 2013-05-04 | 2013-09-04 | 北京航空航天大学 | Optical fiber IMU (inertial measurement unit) data collecting system for unmanned aerial vehicle electric power routing inspection |
| CN103744372A (en) * | 2013-12-23 | 2014-04-23 | 广东电网公司电力科学研究院 | Multisensor time synchronization method for unmanned plane power patrol and system thereof |
| CN103823231A (en) * | 2014-02-25 | 2014-05-28 | 清华大学 | Time synchronization method and system suitable for deep integration of GNSS and MIMU |
| CN106154299A (en) * | 2016-06-22 | 2016-11-23 | 陕西宝成航空仪表有限责任公司 | A kind of GPS/SINS integrated navigation system method for synchronizing time |
| CN205843666U (en) * | 2016-07-12 | 2016-12-28 | 国网新疆电力公司博尔塔拉供电公司 | A kind of depopulated helicopter three dimensional data collection and cruising inspection system |
| US10209076B1 (en) * | 2017-03-29 | 2019-02-19 | Rockwell Collins, Inc. | Air data, attitude and heading reference system (ADAHRS) replacement architecture |
| CN110599570A (en) * | 2019-09-17 | 2019-12-20 | 武汉中海庭数据技术有限公司 | Map generation method and system based on crowdsourcing data open scene |
| CN110865406A (en) * | 2019-11-28 | 2020-03-06 | 湖南率为控制科技有限公司 | Multi-sensor data synchronous processing system and method based on vehicle-mounted GPS time service system |
| CN111007554A (en) * | 2019-12-11 | 2020-04-14 | 武汉海达数云技术有限公司 | Data acquisition time synchronization system and method |
-
2020
- 2020-11-16 CN CN202011280783.5A patent/CN112383675B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103279058A (en) * | 2013-05-04 | 2013-09-04 | 北京航空航天大学 | Optical fiber IMU (inertial measurement unit) data collecting system for unmanned aerial vehicle electric power routing inspection |
| CN103744372A (en) * | 2013-12-23 | 2014-04-23 | 广东电网公司电力科学研究院 | Multisensor time synchronization method for unmanned plane power patrol and system thereof |
| CN103823231A (en) * | 2014-02-25 | 2014-05-28 | 清华大学 | Time synchronization method and system suitable for deep integration of GNSS and MIMU |
| CN106154299A (en) * | 2016-06-22 | 2016-11-23 | 陕西宝成航空仪表有限责任公司 | A kind of GPS/SINS integrated navigation system method for synchronizing time |
| CN205843666U (en) * | 2016-07-12 | 2016-12-28 | 国网新疆电力公司博尔塔拉供电公司 | A kind of depopulated helicopter three dimensional data collection and cruising inspection system |
| US10209076B1 (en) * | 2017-03-29 | 2019-02-19 | Rockwell Collins, Inc. | Air data, attitude and heading reference system (ADAHRS) replacement architecture |
| CN110599570A (en) * | 2019-09-17 | 2019-12-20 | 武汉中海庭数据技术有限公司 | Map generation method and system based on crowdsourcing data open scene |
| CN110865406A (en) * | 2019-11-28 | 2020-03-06 | 湖南率为控制科技有限公司 | Multi-sensor data synchronous processing system and method based on vehicle-mounted GPS time service system |
| CN111007554A (en) * | 2019-12-11 | 2020-04-14 | 武汉海达数云技术有限公司 | Data acquisition time synchronization system and method |
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112821980A (en) * | 2021-04-19 | 2021-05-18 | 杭州康吉森自动化科技有限公司 | Clock synchronization system, method and device for industrial automation system |
| CN113176591A (en) * | 2021-05-19 | 2021-07-27 | 浙江宇视科技有限公司 | Time synchronization method and device of monitoring platform, electronic equipment and storage medium |
| CN114220255A (en) * | 2021-12-29 | 2022-03-22 | 宜昌测试技术研究所 | Distributed acoustic equipment synchronous control system and method |
| CN114220255B (en) * | 2021-12-29 | 2024-05-10 | 宜昌测试技术研究所 | Distributed acoustic equipment synchronous control system and method |
| CN114812673A (en) * | 2022-04-02 | 2022-07-29 | 北京卫星环境工程研究所 | Multi-parameter multi-module optical fiber data synchronous testing method |
| CN114812673B (en) * | 2022-04-02 | 2023-11-10 | 北京卫星环境工程研究所 | Multi-parameter multi-module optical fiber data synchronous test method |
| CN114755693A (en) * | 2022-06-15 | 2022-07-15 | 天津大学四川创新研究院 | Infrastructure facility measuring system and method based on multi-rotor unmanned aerial vehicle |
| CN114755693B (en) * | 2022-06-15 | 2022-09-16 | 天津大学四川创新研究院 | Infrastructure facility measuring system and method based on multi-rotor unmanned aerial vehicle |
| CN116600211A (en) * | 2023-06-09 | 2023-08-15 | 苏州洞悉科技有限公司 | Imaging system |
| CN116600211B (en) * | 2023-06-09 | 2024-01-02 | 苏州洞悉科技有限公司 | Imaging system |
| CN117713982A (en) * | 2024-02-04 | 2024-03-15 | 合肥国家实验室 | Method and system for improving time synchronization precision of space laser communication |
| CN117713982B (en) * | 2024-02-04 | 2024-04-26 | 合肥国家实验室 | Method and system for improving time synchronization precision of space laser communication |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112383675B (en) | 2023-04-28 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112383675B (en) | Time synchronization method and device and terminal equipment | |
| CN111381487B (en) | Multi-sensor synchronous time service system, method and device and electronic equipment | |
| CN111585682B (en) | Sensor time synchronization method and device and terminal equipment | |
| EP3621286B1 (en) | Method, and apparatus for clock synchronization, device, storage medium and vehicle | |
| US11892571B2 (en) | Methods and systems for online synchronization of sensors of self-driving vehicles (SDV) | |
| CN111007554A (en) | Data acquisition time synchronization system and method | |
| WO2023093054A1 (en) | Data processing method, apparatus, and system, device, and storage medium | |
| CN107707626B (en) | Data acquisition card, data acquisition system and data acquisition method based on FPGA | |
| CN112861660B (en) | Laser radar array and camera synchronization device, method, equipment and storage medium | |
| CN111934843A (en) | Multi-sensor data synchronous acquisition method for intelligent unmanned system | |
| CN104748730A (en) | Device and method for determining exposure moment of aerial survey camera in unmanned aerial vehicle | |
| CN112865902B (en) | Data acquisition and time synchronization method and device, electronic equipment and storage medium | |
| CN111556226A (en) | Camera system | |
| WO2021131788A1 (en) | Information processing device, information processing method, and program | |
| CN112564883A (en) | Time synchronization apparatus, method and automatic driving system | |
| CN112995524A (en) | High-precision acquisition vehicle, and photo exposure information generation system, method and synchronization device thereof | |
| KR101967027B1 (en) | Improved UTC Time Synchronization Method for a Device using GPS Module in Abnormal Operation Condition | |
| US20220178689A1 (en) | Camera triggering and multi-camera photogrammetry | |
| US20230128046A1 (en) | Detection method and computer-readable recording medium storing detection program | |
| CN113890665A (en) | Time synchronization method, system, storage medium and processor | |
| CN113985431A (en) | Data acquisition method, system, device, electronic equipment and storage medium | |
| CN110830718B (en) | Photographing control method, mapping method and related device | |
| RU2789923C2 (en) | Methods and systems for synchronizing sensors of unmanned vehicles (sdv) online | |
| EP4250724A1 (en) | Multi-sensor fusion system and autonomous mobile apparatus | |
| Fasano et al. | Real‐Time Hardware‐in‐the‐Loop Laboratory Testing for Multisensor Sense and Avoid Systems |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |