CN116528194B

CN116528194B - Synchronization system and synchronization method for an autopilot system

Info

Publication number: CN116528194B
Application number: CN202310814005.7A
Authority: CN
Inventors: 李国锋; 张树民
Original assignee: Zhidao Network Technology Beijing Co Ltd
Current assignee: Zhidao Network Technology Beijing Co Ltd
Priority date: 2023-07-05
Filing date: 2023-07-05
Publication date: 2023-10-03
Anticipated expiration: 2043-07-05
Also published as: CN116528194A

Abstract

The application discloses a synchronization system and a synchronization method for an automatic driving system, wherein the synchronization system comprises V2X equipment, domain controller equipment and high-precision RTK equipment, wherein the high-precision RTK equipment is used for inputting time synchronization and positioning signals into the synchronization system, the domain controller equipment also comprises a 1PPS clock synchronization unit and an automatic driving domain controller equipment master control, and the 1PPS clock synchronization unit is used for receiving 1PPS second pulse signals in the time synchronization signals sent by the high-precision RTK equipment; and when the quality of the 1PPS second pulse signal in the time synchronization signal of the high-precision RTK equipment does not meet a preset condition, generating an analog signal of the 1PPS second pulse signal, and respectively inputting the analog signal into a V2X equipment and the automatic driving domain controller equipment for master control. According to the application, on one hand, when GPS signals are lost in a short period, the high-precision synchronization performance of an automatic driving system can be ensured, and on the other hand, the number of GPS antennas can be reduced, and the difficulty of installing the antennas on the roof of the vehicle is reduced.

Description

Synchronization system and synchronization method for an autopilot system

Technical Field

The application relates to the technical field of automatic driving, in particular to a synchronizing system and a synchronizing method for an automatic driving system.

Background

The V2X (Vehicle to everything) equipment is used as a necessary unit in the field of vehicle-road coordination, can provide communication among vehicles, roads and vehicle-clouds, and the automatic driving system can provide relevant information for the automatic driving system by adopting the V2X equipment, so that more basis conditions are provided for decision judgment of the automatic driving system. To achieve these basic functions, V2X devices require timing and location information provided by the GPS module. For the independent V2X equipment, a common GPS module is generally adopted.

In the related art, a high-precision positioning device is needed in an automatic driving system, and a centimeter-level positioning is generally realized by adopting high-precision RTK equipment, meanwhile, the high-precision RTK equipment adopts a double-antenna and double-channel design, so that directional information can be provided for an automatic driving vehicle, and a typical circuit structure is shown in fig. 1. Specifically, the high-precision RTK apparatus employs two high-precision GNSS antennas, which also output time and positioning data to the autopilot controller apparatus. In addition, information interaction is performed between the domain controller master control and the V2X device master control, and is usually implemented by using a network port.

However, the 1PPS second pulse signal of the high-precision RTK apparatus is affected by the environment in which the vehicle on which the autopilot system is mounted travels, and thus high-precision positioning information cannot be accurately provided. Furthermore, high-precision RTK devices typically employ two GNSS antennas while V2X devices would also require at least one GPS antenna, which can create difficulties for practical installation if both are installed on top of an autonomous vehicle.

Disclosure of Invention

The embodiment of the application provides a synchronization system and a synchronization method for an automatic driving system, which are used for providing a scheme for realizing signal synchronization according to GPS environment adaptability and solving the problem of antenna deployment.

The embodiment of the application adopts the following technical scheme:

in a first aspect, embodiments of the present application provide a synchronization system for an autopilot system, wherein the synchronization system includes a V2X device, a domain controller device, and a high-precision RTK device for inputting time synchronization and positioning signals to the synchronization system,

the domain controller device further comprises a 1PPS clock synchronization unit and an autopilot domain controller device master,

the 1PPS clock synchronization unit is used for receiving 1PPS second pulse signals in time synchronization signals sent by the high-precision RTK equipment; and

and when the quality of the 1PPS second pulse signal in the time synchronization signal of the high-precision RTK equipment does not meet a preset condition, generating an analog signal of the 1PPS second pulse signal, and respectively inputting the analog signal into a V2X equipment and the automatic driving domain controller equipment for master control.

In some embodiments, the V2X device is further configured to synchronously receive a positioning signal of the high-precision RTK device;

and/or the number of the groups of groups,

the autopilot domain controller device is also used for synchronously receiving positioning signals of the high-precision RTK device, and the high-precision RTK device at least comprises a high-precision GNSS antenna.

In some embodiments, when a vehicle on which the autopilot system is installed travels to a GPS-anomalous road segment, the V2X device and/or the autopilot controller device master keeps receiving location information of the high-precision RTK device output through an internal IMU and takes the location information as the positioning signal.

In some embodiments, the autopilot controller assembly master is further configured to,

acquiring an operation environment of an automatic driving system from NMEA0183 code stream information output by the high-precision RTK device, wherein the NMEA0183 code stream information at least comprises one of the following information: the star searching number and the working state of the RTK unit are obtained by the RTK unit, and the RTK unit works in a satellite navigation mode or an inertial navigation mode and is a stable solution or a floating solution;

and obtaining the state of the current running environment of the automatic driving system according to the running environment, outputting a control signal to control, and executing corresponding switching actions.

In some embodiments, the 1PPS clock synchronization unit in the domain controller device is further configured to,

in a first state, synchronizing a 1PP second pulse signal output by the high-precision RTK equipment;

and when the high-precision RTK device does not output a 1PPS signal, continuously outputting an analog signal for generating the 1PPS second pulse signal, wherein the analog signal of the 1PPS second pulse signal has the same precision as the 1PPS second pulse signal output by the high-precision RTK device, which is obtained synchronously in the first state.

In some embodiments, the 1PPS clock synchronization unit further comprises: a switch switching unit, the switch switching unit,

and the device is used for responding to a switch_EN signal command output by the main control of the autopilot domain controller device, outputting a 1PPS signal output by the high-precision RTK device and/or outputting an analog signal of the 1PPS second pulse signal to the main control of the autopilot domain controller device and the V2X device.

In some embodiments, the autopilot domain controller device is further configured to determine, by using the code stream information output by the high-precision RTK device, GPS signal quality of a current working environment of the autopilot system.

In some embodiments, the autopilot controller device master is further configured to

When the GPS signal quality of the current working environment of the automatic driving system meets the requirement, the 1PPS second pulse signal output by the high-precision RTK equipment is directly output to the main control of the automatic driving domain controller equipment and the V2X equipment for use.

And when judging that the GPS signal quality of the current working environment of the automatic driving system does not meet the requirement, switching the analog signal output by the 1PPS clock synchronization unit and outputting the switched analog signal to the main control of the automatic driving domain controller equipment and the V2X equipment.

In a second aspect, an embodiment of the present application further provides a synchronization method for an autopilot system, where the synchronization method is applied to the synchronization system in the first aspect, and the synchronization method includes:

the automatic driving domain controller equipment is used for master control to judge the GPS signal quality of the current working environment of an automatic driving system through the code stream information output by the high-precision RTK equipment;

if the main control of the automatic driving domain controller device judges that the GPS signal quality of the current automatic driving system works meets the requirement, outputting a switch_EN low level and controlling a Switch switching unit to directly output a 1PPS second pulse signal output by the high-precision RTK device to the main control of the automatic driving domain controller device and the V2X device for use;

if the main control of the automatic driving domain controller device judges that the GPS signal quality of the current automatic driving system is not in accordance with the requirement, the switch_EN is set to a high level and the Switch switching unit is controlled to output an analog signal of a 1PPS second pulse signal to the main control of the automatic driving domain controller device and the V2X device for continuous use.

The above at least one technical scheme adopted by the embodiment of the application can achieve the following beneficial effects: a V2X device, a domain controller device, and a high precision RTK device are employed in a synchronization system for inputting time synchronization and positioning signals to the synchronization system. The domain controller device further comprises a 1PPS clock synchronization unit and an autopilot domain controller device master control, so that 1PPS second pulse signals in time synchronization signals sent by the high-precision RTK device are received through the 1PPS clock synchronization unit, and the synchronization system adopts time and positioning signals provided by the high-precision RTK device and provides the time and positioning signals for the autopilot domain controller device.

Further, when the quality of the 1PPS second pulse signal in the time synchronization signal of the high-precision RTK device does not meet a preset condition, the 1PPS clock synchronization unit may generate an analog signal of the 1PPS second pulse signal, and input a V2X device and the autopilot domain controller device for master control, respectively. Thereby meeting the requirements of the V2X equipment and the synchronous signals controlled by the automatic driving domain controller equipment. The synchronization system is realized through the inside of the domain controller equipment of the automatic driving system, so that the time synchronization problem of the domain controller equipment and the OBU (on-board V2X equipment) can be solved simultaneously, and the high-precision RTK equipment is directly adopted in the domain controller equipment as a time synchronization and positioning data signal source, so that the antenna is reduced, and meanwhile, the wiring installation of a vehicle (top) is facilitated.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the application and do not constitute a limitation on the application. In the drawings:

fig. 1 is a schematic circuit diagram of a V2X device and a domain controller device in an autopilot system according to the related art when time synchronization is implemented;

FIG. 2 is a schematic diagram of an internal structure of a synchronization system for an autopilot system in accordance with an embodiment of the present application;

FIG. 3 is a schematic circuit diagram of a synchronization system for an autopilot system in accordance with an embodiment of the present application;

fig. 4 is a schematic diagram of a synchronization flow of a synchronization system for an autopilot system according to an embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the technical solutions of the present application will be clearly and completely described below with reference to specific embodiments of the present application and corresponding drawings. It will be apparent that the described embodiments are only some, but not all, embodiments of the application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

The inventor finds that when the V2X equipment in the automatic driving system works normally, the time synchronization signal provided by the GPS is mainly relied on, and the synchronization signal can ensure that all the V2X equipment can transmit and receive communication according to the same time pace.

When the V2X device is used independently, positioning and timing information provided by an internal common GPS module is generally adopted. This is no longer the case in the applicable scenario of the present application.

When the V2X device is applied to an automatic driving system, high-precision positioning and timing information provided by high-precision RTK equipment adopting the automatic driving system can be directly adopted, and the method belongs to the application scene of the application.

When the autopilot vehicle runs to an environment with weak external GPS signals and even signal loss, such as a dense tree area or a tunnel, the high-precision RTK device can still output relatively accurate position information to the autopilot system and the V2X device by means of an internal gyroscope, but cannot output effective 1PPS time synchronization signals, so that the V2X device cannot work normally. Meanwhile, abnormality of equipment outgoing lines which are highly dependent on 1PPS signals in an automatic driving system can be caused.

In addition, because the V2X equipment in the system needs one GPS antenna and the high-precision RTK equipment needs two high-precision GNSS antennas, the GNSS antennas have higher requirements on the environment of the installation position, and the three antennas are all installed at the higher position of the roof, so that the system is difficult to install;

in view of the above-mentioned shortcomings, embodiments of the present application provide a synchronization system for an autopilot system, which employs a high-precision RTK apparatus to provide a master synchronization signal for the synchronization system. The 1PPS signal after domain control synchronization is maintained is adopted in the V2X equipment, and when the automatic driving system operates to a region with weak GPS environment and the 1PPS time synchronization signal of the RTK is lost for a short time, the accurate synchronization of the system can still be maintained, and the normal communication between the V2X equipment is ensured. Meanwhile, the total number of GPS antennas/GNSS numbers of the synchronous system is reduced from 3 to 2, so that the wiring installation of the whole vehicle is facilitated.

The following describes in detail the technical solutions provided by the embodiments of the present application with reference to the accompanying drawings.

The embodiment of the application provides a synchronization system for an autopilot system, as shown in fig. 2, and provides an internal structure schematic diagram of the synchronization system for an autopilot system in the embodiment of the application, where the synchronization system includes a V2X device 220, a domain controller device 210, and a high-precision RTK device 230, where the high-precision RTK device 230 is configured to input a time synchronization and positioning signal to the synchronization system, and the domain controller device 210 further includes a 1PPS clock synchronization unit 240 and an autopilot domain controller device master 250, where the 1PPS clock synchronization unit 240 is configured to receive a 1 second pulse signal in the time synchronization signal sent by the high-precision RTK device 230; and when the quality of the 1PPS second pulse signal in the time synchronization signal of the high-precision RTK device 230 does not meet a preset condition, generating an analog signal of the 1PPS second pulse signal, and inputting the analog signal into the V2X device 220 and/or the autopilot domain controller device master 250, respectively.

Included in the synchronization system are V2X devices 220, domain controller devices 210, and high-precision RTK devices 230. The high-precision RTK device 230 may now provide time synchronization and positioning signals to the domain controller device 210 and the V2X device 220. It should be noted that, because the V2X device 220 adopts the time synchronization and positioning information forwarded by the domain controller device, the V2X device does not include a GPS module portion, so that in terms of hardware installation, the number of GPS antennas is reduced, and the top wiring installation of the vehicle is facilitated.

It should be noted that the V2X device 220 generally includes a V2X module and a main control CPU, and receives a 1PPS second pulse signal through a pps_in interface IN the V2X device, and receives high-precision positioning and time data IN the high-precision RTK device through a positioning data acquisition unit.

It will be appreciated that the time and positioning signals provided in the high precision RTK device 230 may be provided to an autopilot controller master or V2X device. Positioning and vehicle orientation information may be provided in the high-precision RTK device 230 by employing dual antennas and dual paths. Meanwhile, the gyroscope is provided in the high-precision RTK device 230, so that when the autonomous vehicle runs to the tunnel environment and the GPS cannot be positioned, relatively accurate position information can still be output through the high-precision RTK device 230, and meanwhile, the high-precision RTK device is provided for the domain controller and the V2X device.

Further, the domain controller device 210 further includes a 1PPS clock synchronization unit 240 and an autopilot domain controller device master 250, where the 1PPS clock synchronization unit 240 is configured to receive a 1PPS second pulse signal in the time synchronization signal sent by the high-precision RTK device 230. It will be appreciated that the positioning signals, i.e., high precision time and high precision positioning data, sent by the high precision RTK device 230 need not enter the 1PPS clock synchronization unit 240, but instead directly enter the domain controller device and then are sent to the V2X device and/or the positioning data acquisition unit of the domain controller device.

And the 1PPS clock synchronization unit 240 is further configured to generate an analog signal of the 1PPS second pulse signal when the quality of the 1PPS second pulse signal in the time synchronization signal of the high-precision RTK device 230 does not meet a preset condition, and input the analog signal to the V2X device 220 and/or the autopilot domain controller device master 250, respectively. The 1PPS clock synchronization unit 240 receives the 1PPS second pulse signal in the time synchronization signal, determines whether the signal quality thereof satisfies a condition, and if the signal quality satisfies the condition, generates an analog signal of the 1PPS second pulse signal, and then inputs the analog signal of the 1PPS second pulse signal to the V2X device 220 and/or the autopilot domain controller device master 250.

Illustratively, the positioning is implemented at the V2X device 220 continuously receiving 1PPS second pulse signals or analog signals of 1PPS second pulse signals. The autopilot controller device master 250 determines whether to receive a 1PPS second pulse signal or an analog signal of the 1PPS second pulse signal according to whether a high precision PPS second pulse signal is required in the current environment.

It can be understood that the 1PPS clock synchronization unit 240 needs to have a synchronization maintaining function, and is specific to a use scenario of an autopilot system, and since the autopilot system includes a domain controller device and an OBU device with high precision RTK device, and the domain control and the OBU in the autopilot system both use synchronization signals provided by the high precision RTK device, the 1PPS clock synchronization unit 240 is implemented on a motherboard of the domain controller device, and can be provided for an autopilot domain controller master control and an external OBU device (vehicle-mounted V2X module) to use. The synchronization hold function of the 1PPS clock synchronization unit 240 is continuously generated after receiving a 1PPS second pulse signal in the time synchronization signal of the high precision RTK device 230. Meanwhile, the 1PPS second pulse signal in the time synchronization signal of the high-precision RTK device 230 is input to the autopilot domain controller device master control 250 to perform signal quality judgment, and a corresponding switch switching signal is generated according to the judgment result.

It should be noted that the 1PPS clock synchronization unit 240 also needs to have a switch function, that is, according to a signal command output by the autopilot domain controller master, the 1PPS signal output by the high-precision RTK device or the pps_simultaneous analog signal generated in the 1PPS synchronization holding unit is output to the autopilot domain controller master and the V2X device.

Through the synchronization system for the automatic driving system, the communication problem of the main control of the automatic driving domain controller and the OBU (on-board V2X) can be simultaneously solved, and the synchronization source adopted in the synchronization system is high-precision RTK equipment in the domain control system. In this way, the domain controller device can synchronously maintain the 1PPS signal in the synchronous signals output by the high-precision RTK device and simultaneously provide the synchronous signals for the V2X unit in the synchronous system.

With the synchronization system for the autopilot system, since the 1PPS clock synchronization unit generates the analog signal of the 1PPS second pulse signal when the quality of the 1PPS second pulse signal in the time synchronization signal of the high-precision RTK apparatus does not satisfy a preset condition, and inputs the analog signal to the V2X apparatus and the autopilot domain controller apparatus master control, respectively. When the GPS signal is lost in a short period, the system can be guaranteed to have higher-precision synchronization performance, and the automatic driving domain controller master control during the period of the GPS signal loss, the V2X equipment serving as the vehicle-mounted OBU and the normal operation of equipment with higher dependence on 1PPS synchronization signals are guaranteed.

Through above-mentioned synchronization system for autopilot system, because V2X equipment is when regard as on-vehicle OBU to use, directly adopts the high accurate location and the time service information that autopilot system RTK equipment provided, this design reduces the total number of GPS antenna/GNSS antenna, can reduce the degree of difficulty of roof antenna installation. That is, only two high-precision GNSS antennas adopted by the high-precision RTK apparatus are required. It is also possible to output highly accurate time and positioning data to the autopilot controller apparatus.

In contrast to the related art, information interaction between the autopilot controller master control and the V2X device master control is generally implemented by using a portal. By adopting the synchronization system, the positioning signals of the high-precision RTK equipment are directly transmitted to the main control of the autopilot domain controller and the V2X equipment, and the positioning signals and the V2X equipment do not need to be subjected to information interaction, and are mutually independent.

In contrast to the problem that high-precision positioning adjustment cannot be adaptively achieved in the related art, by adopting the synchronization system, the running environment of the automatic driving system is obtained from NMEA0183 code stream information output by high-precision RTK equipment through the domain controller equipment, and when the 1PPS clock synchronization unit of the domain controller equipment considers that the automatic driving system runs in the environment with good GPS signals, a control signal is output to enable the 1PPS signals output by the RTK unit to be directly output to the domain control master control and V2X equipment.

Further, when the 1PPS clock synchronization unit of the domain controller device detects that the autopilot system is operated to the GPS signal loss or signal degradation environment, the pps_synchronous signal output by the synchronization maintenance function unit is controlled to be output to the autopilot domain controller master control and the V2X device.

In contrast to the problem that the domain controller device needs to judge by other perception modules that the autonomous vehicle is currently running to the environment where the external GPS signal is weak or even the signal is lost in the related art, by adopting the synchronization system, the domain controller device judges the quality of the synchronization signal according to the newly added 1PPS clock synchronization unit by receiving timing and position information sent by the RTK, and simultaneously keeps the original synchronization signal quality for a period of time to generate an analog signal of 1PPS second pulse signal, and the analog signal is directly input to the vehicle-mounted V2X device or the autonomous domain controller device for master control.

In one embodiment of the present application, the V2X device is further configured to synchronously receive a positioning signal of the high-precision RTK device; and/or the autopilot domain controller device is used for master control and is also used for synchronously receiving the positioning signals of the high-precision RTK device, and the high-precision RTK device at least comprises a high-precision GNSS antenna.

Referring to fig. 3, the high-precision GNSS antenna includes at least two antennas. The 1PPS clock synchronization unit can directly output the 1PPS second pulse signal output by the RTK unit to the domain control main control and the V2X equipment, or output the analog signal of the 1PPS second pulse signal to the domain control main control and the V2X equipment.

In addition, for the V2X device itself, the V2X device no longer includes a GPS module portion inside due to the time synchronization and positioning information forwarded by the domain controller device. Therefore, the number of GPS antennas outside the system is reduced, and the wiring installation of the vehicle is facilitated.

In one embodiment of the present application, when a vehicle on which the autopilot system is mounted travels to a road segment where GPS is abnormal, the V2X device and/or the autopilot controller device master keeps receiving position information of the high-precision RTK device output through an internal IMU and takes the position information as the positioning signal.

When a vehicle carrying the autopilot system runs to a road section with abnormal GPS, and the V2X device and the autopilot domain controller device master control needs high-precision time and positioning data, the V2X device and the autopilot domain controller device keep receiving the position information output by the high-precision RTK device through the internal IMU and serve as the positioning signal. Since the PPS second pulse signal in the high-precision RTK apparatus cannot be obtained by calculation or is not outputted, an analog signal of the 1PPS second pulse signal is also required to be received as a time synchronization signal. Together, as time, positioning data, and timing signals.

When a vehicle carrying the autopilot system travels to a road section with abnormal GPS, and the V2X device or the autopilot domain controller device master control requires high-precision time and positioning data, one of the V2X device or the autopilot domain controller device keeps receiving position information output by an internal IMU of the high-precision RTK device and serves as the positioning signal. Since the PPS second pulse signal in the high-precision RTK apparatus cannot be obtained by calculation or is not output at this time, an analog signal of the 1PPS second pulse signal is also required to be received as a time synchronization signal. Together, as time, positioning data, and timing signals.

In one embodiment of the present application, the autopilot domain controller device master is further configured to obtain an operating environment of an autopilot system from NMEA0183 bitstream information output by the high-precision RTK device, where the NMEA0183 bitstream information includes at least one of the following information: the star searching number and the working state of the RTK unit are obtained by the RTK unit, and the RTK unit works in a satellite navigation mode or an inertial navigation mode and is a stable solution or a floating solution; and obtaining the state of the current running environment of the automatic driving system according to the running environment, outputting a control signal to control, and executing corresponding switching actions.

It should be noted here that the master control can determine the signal quality of the PPS second pulse signal transmitted in the 1PPS clock synchronization unit at the autopilot domain controller. Specifically, the running environment of the autopilot system is obtained from NMEA0183 code stream information output by the high-precision RTK device in the domain controller device or autopilot domain controller device master control, and when the autopilot system runs in a better GPS signal environment, the output control signal adopts a 1PPS signal output by the high-precision RTK device to be directly output to the domain control master control and the V2X device.

Further, when the autopilot system is detected to run to a GPS signal loss or signal degradation environment, the master control of the domain controller device or the autopilot domain controller device outputs a PPS_Simmulate signal output by the synchronous holding functional unit to the domain control master control and the V2X device.

For processing NMEA0183 code stream information, the number of search stars, the working state of RTK equipment, whether the RTK works in a satellite navigation mode or an inertial navigation mode, whether the RTK is stable solution or floating solution can be comprehensively judged, so that the state of the current running environment of an automatic driving system and whether GPS environment signals are good enough or not can be obtained, and then the automatic driving domain controller is used for controlling the switching action of a Switch by outputting a control signal switch_EN.

It should be noted that the 1PPS clock synchronization unit is used for monitoring signals and maintaining the signals synchronously, and specific judgment logic is input to the autopilot domain controller master control to complete the operation, and generates corresponding switch control signals.

In one embodiment of the present application, the 1PPS clock synchronization unit in the domain controller device is further configured to synchronize, in an initial state, a 1PP second pulse signal output by the high-precision RTK device; and when the high-precision RTK device does not output a 1PPS signal, continuously outputting an analog signal for generating the 1PPS second pulse signal, wherein the analog signal of the 1PPS second pulse signal has the same precision as the 1PPS second pulse signal output by the high-precision RTK device, which is obtained synchronously in an initial state.

Referring to fig. 3, when the 1PPS signal output by the RTK apparatus is initially synchronized, and the GPS signal is lost due to the vehicle carrying the autopilot system running to a blocking environment or other factors, the 1PPS clock synchronization unit may continuously output the pps_frame signal that is simulated by itself when the 1PPS signal of the RTK apparatus is not output. It should be noted that the analog signal is continuously output and is not intermittent. The pps_simultaneous signal at the previous time of each time can be simulated corresponding to the 1PPS second pulse signal interval of the high-precision RTK apparatus.

Further, since the 1PPS signal output by the RTK apparatus is initially synchronized, the analog pps_simultaneous signal output by the unit can maintain high time precision and accuracy relative to the actual 1PPS signal in a short period of time, so that the analog pps_simultaneous signal is relatively high in precision and real-time.

In one embodiment of the present application, the 1PPS clock synchronization unit further includes: and the Switch switching unit is used for responding to a switch_EN signal command output by the main control of the autopilot domain controller device, outputting a 1PPS signal output by the high-precision RTK device and/or outputting an analog signal of the 1PPS second pulse signal to the main control of the autopilot domain controller device and the V2X device.

Referring to fig. 3, according to the domain controller master control output signal command, a 1PPS signal or pps_synchronous signal of the synchronization holding function holding unit output by the high-precision RTK device is output to the domain controller master control and the V2X device.

Note that, the switch_en is a control signal for controlling the switch_en to Switch by judging the system operating environment according to the information in the NMEA0183 code stream outputted by the RTK.

Specifically, the autopilot domain controller hosts a search star number that can be obtained by an RTK unit (device) in an NMEA0183 code stream; the working state of RTK equipment; whether to operate in satellite navigation mode or inertial navigation mode; the RTK is a stable solution or a floating solution to comprehensively judge, so as to obtain the state of the current running environment of the automatic driving system and whether the GPS environment signal is good enough or not, and then a control signal switch_EN is output to control the switching action of the Switch.

It can be understood that the obtained star searching number; the working state of RTK equipment; whether to operate in satellite navigation mode or inertial navigation mode; the manner in which an RTK is a stable solution or a floating solution is well known to those skilled in the art and will not be described in detail herein.

In one embodiment of the present application, the autopilot domain controller device is further configured to determine, via the code stream information output by the high-precision RTK device, GPS signal quality of a current working environment of the autopilot system.

Referring to fig. 3, the domain controller device obtains the running environment of the autopilot system from NMEA0183 code stream information output by the RTK, and when the system runs in a better environment of the GPS signal, outputs a control signal to enable the 1PPS signal output by the RTK unit to be directly output to the domain control master control and the V2X device; when the main control of the automatic driving domain controller detects that the automatic driving system runs to the GPS signal loss or signal degradation environment, the PPS_Simuline signal output by the synchronous holding functional unit is controlled to be output to the domain control main control and the V2X device.

In one embodiment of the present application, the autopilot domain controller device master control is further configured to directly output the 1PPS second pulse signal output by the high-precision RTK device to the autopilot domain controller device master control and the V2X device for use when it is determined that the GPS signal quality of the current working environment of the autopilot system meets a requirement.

As shown in fig. 4, the above operation is performed before step S410 is included, the system is powered on, and the program is run. In step S420, switch_en is pre-controlled master low. Step S430, transmitting the high-precision 1PPS synchronization signal generated by the external RTK to the domain controller and the V2X device. Step S440, the domain master control judges whether the GPS signal quality of the current working environment of the automatic driving system is better.

When the system is powered on, the switch_EN signal is set low under the default condition, and the equipment is in a normal working state; and then the domain controller is used for master control of code stream information output by the RTK and judging the GPS signal quality of the current working environment of the automatic driving system.

As shown in fig. 4, the method specifically comprises the following steps:

step S460, the GPS environment where the autopilot system works is better.

In step S480, the master sets the output signal switch_en to a low level.

In step S4100, the switch switching unit gives the high-precision 1PPS signal input by the RTK to the domain control master and the V2X device for use.

Specifically, if the domain control master control considers that the GPS signal quality of the current system work is better, the output switch_EN is set to a low level; and controlling the change-over switch to directly output the 1PPS signal output by the RTK unit to the domain control main control and the V2X equipment for use.

In one embodiment of the present application, the autopilot domain controller device master control is further configured to switch the analog signal output by the 1PPS clock synchronization unit and output the switched analog signal to the autopilot domain controller device master control and the V2X device when it is determined that the GPS signal quality of the current working environment of the autopilot system does not meet the requirement.

As shown in fig. 4, the method specifically comprises the following steps:

in step S450, the GPS environment in which the autopilot system operates becomes worse.

In step S470, the master sets the output signal switch_en high.

In step S490, the switch switching unit sends the pps_simultaneous signal outputted by the synchronization holding unit to the domain master control and the V2X device for use.

In particular, if the domain control master control judges that the GPS signal quality of the current system work is poor, the communication between the system and the V2X equipment is not facilitated, setting the output switch_EN to high level, and controlling a change-over Switch to Switch and output the analog PPS_Simuline signal output by the internal synchronous holding unit to the domain control main control and the V2X equipment for use; the system and the V2X equipment can be ensured to work normally.

The embodiment of the application also provides a synchronization method for an automatic driving system, wherein the synchronization method is applied to the synchronization system and comprises the following steps:

the use scenario of the above synchronization method is an autopilot system, which comprises a domain controller device and an OBU device high-precision RTK device, and the domain control and the OBU in the autopilot system both usually use synchronization signals provided by the high-precision RTK device. The domain control unit on the domain controller main board realizes the signal detection and holding functions through the 1PPS clock synchronization unit, and simultaneously provides time synchronization signals meeting the requirements for the domain control main control and external OBU equipment.

S1, the main control of an autopilot domain controller judges the GPS signal quality of the current working environment of an autopilot system through code stream information output by high-precision RTK equipment;

the state of the current running environment of the automatic driving system and whether GPS environment signals are good enough can be obtained through comprehensively judging the number of search stars, the working state of the RTK equipment, whether the RTK equipment works in a satellite navigation mode or an inertial navigation mode and whether the RTK is a stable solution or a floating solution, and then the automatic driving domain controller is used for controlling the switching action of a Switch through the main control output control signal switch_EN.

S2, if the main control of the automatic driving domain controller equipment judges that the GPS signal quality of the current automatic driving system works meets the requirement, outputting a switch_EN low level and controlling a Switch switching unit to directly output a 1PPS second pulse signal output by the high-precision RTK equipment to the main control of the automatic driving domain controller equipment and the V2X equipment for use;

if the GPS signal quality of the current system work is considered to be better, the output switch_EN is set to be low level; and controlling the change-over switch to directly output the 1PPS signal output by the RTK unit to the domain control main control and the V2X equipment for use.

And S3, if the main control of the automatic driving domain controller equipment judges that the GPS signal quality of the current automatic driving system is not in accordance with the requirement, outputting a switch_EN high level and controlling a Switch switching unit to output an analog signal of a 1PPS second pulse signal to the main control of the automatic driving domain controller equipment and the V2X equipment for continuous use.

If judging that the GPS signal quality of the current system working is poor and is not beneficial to the communication between the system and the V2X equipment, setting the output switch_EN to a high level, and controlling a change-over Switch to Switch and output the analog PPS_Simuline signal output by the internal synchronous holding unit to the domain control main control and the V2X equipment for use; the system and the V2X equipment can be ensured to work normally.

The foregoing is merely exemplary of the present application and is not intended to limit the present application. Various modifications and variations of the present application will be apparent to those skilled in the art. Any modification, equivalent replacement, improvement, etc. which come within the spirit and principles of the application are to be included in the scope of the claims of the present application.

Claims

1. A synchronization system for an autopilot system, wherein the synchronization system comprises a V2X device, a domain controller device, and a high precision RTK device for inputting time synchronization and positioning signals to the synchronization system,

when the quality of a 1PPS second pulse signal in the time synchronization signal of the high-precision RTK device does not meet a preset condition, generating an analog signal of the 1PPS second pulse signal to synchronously hold the 1PPS signal in the synchronization signal output by the high-precision RTK device, respectively inputting the 1PPS signal to a V2X device and an autopilot domain controller device for master control, wherein the high-precision RTK device is used as a synchronization source in the synchronization system, the analog signal of the 1PPS second pulse signal has the same precision as the 1PPS second pulse signal output by the high-precision RTK device, which is synchronously obtained in an initial state, and the 1PPS clock synchronization unit is also used for synchronizing the 1PPS second pulse signal output by the high-precision RTK device in the initial state;

when the V2X equipment is used as a vehicle-mounted OBU, the V2X equipment is also used for synchronously receiving the positioning signals of the high-precision RTK equipment;

2. The synchronization system of claim 1, wherein,

when a vehicle carrying the autopilot system runs to a road section with abnormal GPS, the V2X device and/or the autopilot domain controller device master control keeps receiving the position information output by the high-precision RTK device through an internal IMU and takes the position information as the positioning signal.

3. The synchronization system of claim 2, wherein the autopilot controller appliance master is further configured to,

4. The synchronization system of claim 1, wherein the 1PPS clock synchronization unit in the domain controller device is further configured to,

in an initial state, synchronizing 1PPS second pulse signals output by the high-precision RTK equipment;

and when the high-precision RTK equipment does not output the 1PPS signal, continuously outputting an analog signal for generating the 1PPS second pulse signal.

5. The synchronization system of claim 4, wherein the 1PPS clock synchronization unit further comprises: a switch switching unit, the switch switching unit,

6. The synchronization system of claim 1, wherein,

the automatic driving domain controller equipment is used for controlling the main control and judging the GPS signal quality of the current working environment of the automatic driving system through the code stream information output by the high-precision RTK equipment.

7. The synchronization system of claim 6, wherein the autopilot controller appliance master is further configured to

8. The synchronization system of claim 6, wherein the autopilot controller appliance master is further configured to

And when the GPS signal quality of the current working environment of the automatic driving system is judged to be not in accordance with the requirement, outputting the analog signal output by the 1PPS clock synchronization unit to the main control of the automatic driving domain controller equipment and the V2X equipment.

9. A synchronization method for an autopilot system, wherein applied to the synchronization system of claim 1, the synchronization method comprising: