Method for transmitting digital information in remote interaction of a ship

Abstract

The present application relates to the field of ship remote communication technology, in particular to a digital information transmission method in ship remote interaction. The shore base calculates the expected execution time according to the instruction type, speed, rudder angle deviation and sea state level, and determines the dynamic triggering threshold of the intermediate progress confirmation signal in combination with the transmission delay; the ship end execution mechanism returns the execution confirmation signal in turn according to the execution progress; after receiving the intermediate progress confirmation signal, the shore base pre-transmits the subsequent strong dependence instruction together with the state parameter verification boundary to the ship end buffer area, and triggers the buffer instruction execution after receiving the completion confirmation signal; the ship end continuously verifies the compliance of the state parameter, and invalidates the buffer instruction if the verification fails; when the execution confirmation signal does not advance according to the stage, the execution mechanism exception and channel interruption are distinguished and differentiated recovery strategies are adopted. The present application effectively eliminates the transmission delay lag of strong dependence instruction, and guarantees the safety of remote control execution.

Description

Technical Field

[0001] This invention relates to the field of ship remote communication technology, specifically to a method for transmitting digital information in remote ship interaction. Background Technology

[0002] With the development of remote ship control technology, the real-time transmission and execution management of shipboard actuators via wireless channels from shore has become a core requirement of intelligent shipping.

[0003] However, existing remote control systems have significant shortcomings in continuous command transmission. First, shore-based systems typically initiate the transmission of subsequent commands only after receiving a completion confirmation signal for the current command. Subsequent commands with execution dependencies therefore lag behind the completion time of the current command by at least one full round-trip channel delay. In complex sea conditions, this delay can reach several seconds to over ten seconds, posing a safety threat to subsequent commands that must be executed sequentially within a strict time window. Second, existing systems lack a dynamic adaptation mechanism to channel delay fluctuations. Command transmission with a fixed timing can easily lead to subsequent commands failing to arrive on time when sea conditions deteriorate or channel delays significantly increase. Third, while subsequent commands are awaiting execution, the ship's status may deviate due to wind and current. Existing systems lack real-time compliance verification of command execution conditions, posing a safety hazard of forcibly executing subsequent commands when the ship's status has deviated from a safe range. Summary of the Invention

[0004] This invention provides a digital information transmission method for remote interaction of ships, which solves the execution safety problems caused by the delay in the execution of continuous commands and the state deviation during remote control.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] The present invention provides a digital information transmission method for remote ship communication, comprising:

[0007] S100: Based on the current control command type, the ship's current speed, rudder angle deviation, and sea state level, calculate the expected execution time of the control command, and determine the dynamic trigger threshold of the intermediate progress confirmation signal based on the transmission delay of subsequent highly dependent commands and the channel delay fluctuation range corresponding to the current sea state level.

[0008] S200: After sending the control command to the ship, the ship-side actuators sequentially return execution confirmation signals to the shore according to the execution progress, including a start confirmation signal, an intermediate progress confirmation signal, and a completion confirmation signal; wherein the intermediate progress confirmation signal is issued when the execution progress reaches the dynamic triggering threshold.

[0009] S300: After receiving the intermediate progress confirmation signal, the shore-based system pre-transmits subsequent highly dependent instructions along with the status parameter verification boundary to the ship's buffer area. The status parameters include speed, rudder angle, heading angle, and distance to surrounding obstacles. After receiving the completion confirmation signal, the system triggers the execution of subsequent highly dependent instructions in the buffer area.

[0010] S400: During the waiting period for subsequent strongly dependent instructions, the ship continuously collects the ship's current status parameters. When the deviation between the current value of any status parameter and the corresponding value at the pre-transmission time exceeds the preset change threshold, the compliance check between the current status parameter and the status parameter verification boundary is triggered. If the check fails, the cached instructions are invalidated and a failure notification is returned to the shore.

[0011] S500: When the execution confirmation signal fails to advance in stages within the expected time window, it distinguishes between two causes: actuator abnormality and channel interruption, and adopts a differentiated recovery strategy.

[0012] As a preferred embodiment of the present invention, in S100, the calculation of the expected execution time includes:

[0013] Retrieve the base execution time corresponding to the current control command type from the preset command template library;

[0014] The base execution time is corrected using the ship's current speed, the difference between the current rudder angle and the target rudder angle, and the sea state level as correction factors to obtain the expected execution time.

[0015] As a preferred embodiment of the present invention, in S100, the construction of the preset instruction template library includes:

[0016] Collect the actual execution time of each control command type in historical control tasks;

[0017] The deviation between the actual execution time and the base execution time is calculated. When the number of deviations for the same control instruction type exceeds the preset deviation threshold, the corresponding base execution time is updated with the statistical average of the actual execution time, and the updated base execution time is stored in the preset instruction template library.

[0018] As a preferred embodiment of the present invention, the subsequent strongly dependent instruction is a subsequent instruction that satisfies any of the following conditions:

[0019] The object to which the subsequent instruction is executed has a direct mechanical transmission or pipeline connection with the object to which the current instruction is executed;

[0020] The execution parameters for subsequent instructions are based on the execution result of the current instruction;

[0021] Subsequent instructions must be executed within a preset time window after the current instruction is completed; otherwise, the ship's status will deviate from the safe operating range.

[0022] As a preferred embodiment of the present invention, in S100, the determination of the dynamic triggering threshold includes:

[0023] The forward transmission delay required to transmit subsequent strongly dependent commands from the shore to the ship, and the reverse transmission delay required to complete the confirmation signal from the ship back to the shore;

[0024] The dynamic trigger threshold is determined by the ratio of the expected execution time minus the sum of the forward transmission delay, the reverse transmission delay, and the ship's end cache instruction readiness time, to the expected execution time.

[0025] As a preferred embodiment of the present invention, in S100, the dynamic triggering threshold is further corrected according to the current sea state level, including:

[0026] Obtain the channel delay fluctuation range corresponding to the current sea state level, replace the forward transmission delay with the upper limit of the channel delay fluctuation range, recalculate the dynamic trigger threshold, and use it as the corrected dynamic trigger threshold under the current sea state.

[0027] When the actual forward transmission delay is detected to exceed the channel delay fluctuation range before the pre-transmission is executed, the dynamic trigger threshold is recalculated by replacing the forward transmission delay with the actual forward transmission delay, and the updated dynamic trigger threshold is synchronized to the ship end.

[0028] After receiving the updated dynamic trigger threshold, the ship reassesses whether the pretransmission can arrive before the expected completion time of the current instruction. If it cannot arrive, the current pretransmission process is terminated and the shore is notified.

[0029] As a preferred embodiment of the present invention, in S300, the state parameter verification boundary includes:

[0030] The valid range of values ​​for status parameters related to the execution of subsequent strongly dependent instructions;

[0031] The maximum allowable change in the status parameter between the pre-transmission time and the trigger execution time, i.e., the preset change threshold;

[0032] The state parameter verification boundary is determined by the shore-based system based on the ship's state at the pre-transmission time, and is transmitted to the ship's buffer along with subsequent strongly dependent instructions.

[0033] As a preferred embodiment of the present invention, in S400, the compliance verification includes:

[0034] When the current value of any of the aforementioned state parameters exceeds the valid value range, the verification is determined to be unsuccessful, the cache instruction is set to invalid, and a failure notification is returned to the shore base.

[0035] When the current value of any of the aforementioned state parameters does not exceed the valid value range, but the difference between the current value and the parameter value corresponding to the pre-transmission time exceeds the preset change threshold, the verification is determined to be unsuccessful, the cache instruction is set to invalid, and a failure notification is returned to the shore base.

[0036] As a preferred embodiment of the present invention, in S500, the differentiated recovery strategy specifically includes:

[0037] When the communication link between the shore base and the ship remains normal but the execution confirmation signal does not advance in stages, it is determined that the actuator is abnormal;

[0038] Suspend all pending command transmissions from shore to ship and return an exception notification to shore containing the exception command identifier, the time of the exception, and the last known execution progress, and resume transmission after shore reissues the command;

[0039] When the communication link between the shore base and the ship is interrupted and the confirmation signal synchronization is interrupted, it is determined as a channel interruption;

[0040] Record the type and time of the last received execution confirmation signal. After the channel is restored, request a snapshot of the current execution progress from the ship. Determine the starting instruction for resuming transmission based on the dependency relationship between the execution progress snapshot and subsequent strongly dependent instructions.

[0041] As a preferred embodiment of the present invention, the step of determining the start instruction for resuming transmission based on the dependency relationship between the execution progress snapshot and subsequent strongly dependent instructions specifically includes:

[0042] If the current instruction has been completed and a subsequent strongly dependent instruction has been triggered and executed, then the transmission resumes from the instruction following the strongly dependent instruction.

[0043] If the current instruction has not yet been completed, the dynamic trigger threshold will be recalculated based on the actual execution progress in the execution progress snapshot and the progress monitoring process will continue.

[0044] If the current instruction has been completed but subsequent strongly dependent instructions have not been triggered due to cache invalidation or verification failure, the transmission is re-initiated from the subsequent strongly dependent instructions, thereby avoiding repeated or missed execution of instructions.

[0045] The beneficial effects of this invention are:

[0046] 1. By initiating the pre-transmission of subsequent instructions when the current instruction execution progress reaches the dynamic trigger threshold, the delay in the connection of subsequent instructions is compressed from the full channel round-trip time to the buffer trigger response time, eliminating the risk that subsequent instructions cannot be ready within the safe time window due to waiting for transmission in the traditional method.

[0047] 2. The dynamic trigger threshold comprehensively considers the expected execution time, channel transmission delay, and the delay fluctuation range corresponding to the sea state level. It also supports real-time correction and synchronization to the ship when the actual delay exceeds the fluctuation range, so that the command transmission timing can always maintain adaptive adjustment capability under complex and ever-changing sea state conditions.

[0048] 3. During the waiting period for the cached instructions to be triggered, the ship continuously collects status parameters and performs compliance verification with the verification boundary at the pre-transmission time. When the ship's status deviates beyond expectations, the cached instructions are proactively invalidated and the shore base is notified, thus intercepting the risk of status deviation before the instructions are executed. This improves the efficiency of instruction transmission while ensuring execution security. Attached Figure Description

[0049] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0050] Figure 1 This is a flowchart illustrating the digital information transmission method in remote ship interaction according to the present invention. Detailed Implementation

[0051] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0052] Example 1: As Figure 1 As shown, the digital information transmission method for remote ship communication of the present invention includes:

[0053] S100: Based on the current control command type, the ship's current speed, rudder angle deviation, and sea state level, calculate the expected execution time of the control command, and determine the dynamic trigger threshold of the intermediate progress confirmation signal based on the transmission delay of subsequent highly dependent commands and the channel delay fluctuation range corresponding to the current sea state level.

[0054] Further, in S100, the calculation of the expected execution time includes:

[0055] Retrieve the base execution time corresponding to the current control command type from the preset command template library;

[0056] The base execution time is corrected using the ship's current speed, the difference between the current rudder angle and the target rudder angle, and the sea state level as correction factors to obtain the expected execution time.

[0057] Furthermore, in S100, the construction of the preset instruction template library includes:

[0058] Collect the actual execution time of each control command type in historical control tasks;

[0059] The deviation between the actual execution time and the base execution time is calculated. When the number of deviations for the same control instruction type exceeds the preset deviation threshold, the corresponding base execution time is updated with the statistical average of the actual execution time, and the updated base execution time is stored in the preset instruction template library.

[0060] Specifically, the preset instruction template library stores the basic execution time corresponding to each control instruction type in advance. This basic execution time is continuously updated and maintained through historical control task data: the number of deviations between the actual execution time of each control instruction type in historical control tasks and the currently stored basic execution time is counted. When the number of deviations for the same control instruction type exceeds the preset deviation threshold, the corresponding basic execution time is replaced with the statistical average of the actual execution time and written into the template library.

[0061] After receiving the control command, the shore-based system retrieves the base execution time corresponding to the current control command type from the preset command template library. Based on the ship's current speed The difference between the current rudder angle and the target rudder angle and current sea state level Calculate the expected execution time using the following formula. :

[0062] ;

[0063] in These are the correction coefficients for speed, rudder angle deviation, and sea state level, respectively, determined by regression fitting of historical control data, reflecting the weight of each factor on execution time. All data is collected in real time by sensors on the ship and then reported to the shore, including speed. The higher the speed, the greater the hydrodynamic load on the hull, increasing the driving force required for the rudder to overcome resistance and thus extending the execution time under the condition of a constant hydraulic system output power. Furthermore, the hull inertia also increases with speed during engine acceleration and deceleration; rudder angle deviation... This reflects the physical travel required for the servo motor to rotate; the greater the deviation, the longer the travel. Under the condition of a fixed rated servo motor speed, the execution time is directly proportional to the deviation. Sea state rating. The higher the hull, the more violent the rolling and pitching, and the greater the dynamic load and hydraulic system pressure fluctuations on the actuators, resulting in a decrease in the actuator response speed and a longer execution time.

[0064] Furthermore, the subsequent strongly dependent instruction is a subsequent instruction that satisfies any of the following conditions:

[0065] The object to which the subsequent instruction is executed has a direct mechanical transmission or pipeline connection with the object to which the current instruction is executed;

[0066] The execution parameters for subsequent instructions are based on the execution result of the current instruction;

[0067] Subsequent instructions must be executed within a preset time window after the current instruction is completed; otherwise, the ship's status will deviate from the safe operating range.

[0068] Further, in S100, determining the dynamic trigger threshold includes:

[0069] The forward transmission delay required to transmit subsequent strongly dependent commands from the shore to the ship, and the reverse transmission delay required to complete the confirmation signal from the ship back to the shore;

[0070] The dynamic trigger threshold is determined by the ratio of the expected execution time minus the sum of the forward transmission delay, the reverse transmission delay, and the ship's end cache instruction readiness time, to the expected execution time.

[0071] Furthermore, in S100, the dynamic trigger threshold is also corrected according to the current sea state level, including:

[0072] Obtain the channel delay fluctuation range corresponding to the current sea state level, replace the forward transmission delay with the upper limit of the channel delay fluctuation range, recalculate the dynamic trigger threshold, and use it as the corrected dynamic trigger threshold under the current sea state.

[0073] When the actual forward transmission delay is detected to exceed the channel delay fluctuation range before the pre-transmission is executed, the dynamic trigger threshold is recalculated by replacing the forward transmission delay with the actual forward transmission delay, and the updated dynamic trigger threshold is synchronized to the ship end.

[0074] After receiving the updated dynamic trigger threshold, the ship reassesses whether the pretransmission can arrive before the expected completion time of the current instruction. If it cannot arrive, the current pretransmission process is terminated and the shore is notified.

[0075] Specifically, dynamic trigger threshold This indicates a percentage point representing the progress of the execution; the execution progress of the ship-side execution mechanism has reached... When an intermediate progress confirmation signal is triggered, the shore-based system will immediately initiate the pre-transmission of subsequent strongly dependent instructions upon receiving the signal. The design goal is to ensure that subsequent strongly dependent instructions are ready on the ship precisely when the current instruction completes. This requires within the expected execution time. The system reserves complete transmission link time, including the reverse transmission delay of intermediate progress confirmation signals from the ship to the shore. The forward transmission delay of subsequent strongly dependent commands from shore-based to ship-based systems. And the cache readiness time required for the ship to complete the parsing and preparation of cache instructions. All three are provided by the communication system in real time. The calculation formula is:

[0076] ;

[0077] The physical meaning is: the execution progress has advanced to At this point, the remaining execution time is exactly equal to the total delay required to complete the aforementioned transmission link. Triggering an intermediate progress confirmation signal at this time ensures that subsequent strongly dependent instructions are ready on time when the current instruction completes. When the calculation result... When this occurs, it indicates that the total latency of the transmission link has exceeded the expected execution time, triggering an alarm and initiating a manual intervention process.

[0078] Due to fluctuations in sea state, channel delay can vary, and calculations using fixed delay parameters are necessary. In rough sea conditions, timely delivery of pre-transmissions may not be guaranteed; therefore, adjustments need to be made based on the current sea state level. Make corrections. Obtain the channel delay fluctuation range corresponding to the current sea state level. With the upper limit of fluctuation Alternative Recalculate to obtain the corrected dynamic trigger threshold. :

[0079] ;

[0080] by As an execution trigger node under normal sea conditions, it can still ensure timely arrival of pre-transmissions even when the channel delay reaches the maximum fluctuation value of the current sea state level.

[0081] Before the pretransmission is executed, the system continuously monitors the actual forward transmission delay. ,when This indicates that the current channel delay has exceeded the fluctuation range corresponding to the sea state level. Alternative Recalculate and obtain the updated threshold :

[0082] ;

[0083] shore base will The message is simultaneously sent to the ship's end, and the ship's end receives it and... Reassess whether the current pre-transmission can arrive before the expected completion time of the current instruction. If it is determined that it cannot arrive in time, the current pre-transmission process is terminated and a termination notice is sent to the shore base, which then reschedules the instruction transmission timing.

[0084] S200: After sending the control command to the ship, the ship-side actuators sequentially return execution confirmation signals to the shore according to the execution progress, including a start confirmation signal, an intermediate progress confirmation signal, and a completion confirmation signal; wherein the intermediate progress confirmation signal is issued when the execution progress reaches the dynamic triggering threshold.

[0085] Specifically, after the shore-based unit issues control commands to the ship, the ship's actuators sequentially return execution confirmation signals to the shore-based unit according to the execution progress during the execution process.

[0086] After receiving the control command and initiating its execution, the actuator immediately sends a start confirmation signal back to the shore-based base. This signal carries the command identifier and the start time, and is used to inform the shore-based base that the current command has entered the execution state.

[0087] During execution, the executing agency continuously reports the current execution progress. When the execution progress reaches the dynamic trigger threshold defined in S100, it returns an intermediate progress confirmation signal to the shore base. The intermediate progress confirmation signal carries the instruction identifier, the current execution progress, and the time the signal was sent. Upon receiving this signal, the shore base immediately initiates the pre-transmission process for subsequent strongly dependent instructions.

[0088] After the actuator completes all the actions of the current control command, it returns a completion confirmation signal to the shore. This signal carries the command identifier, completion time, and execution result summary. Upon receiving the completion confirmation signal, the shore triggers the execution of subsequent highly dependent commands in the ship's buffer area.

[0089] The aforementioned execution confirmation signals together constitute a complete execution progress feedback chain. The start confirmation signal ensures that the shore-based system is aware of the start status of the instruction execution. The intermediate progress confirmation signal drives the early start of the pre-transmission process to eliminate the impact of transmission delay on the connection of highly dependent instructions. The completion confirmation signal serves as the final triggering basis for subsequent highly dependent instructions. The three work together to ensure that the shore-based system and the ship-based system are synchronized throughout the entire instruction execution process.

[0090] S300: After receiving the intermediate progress confirmation signal, the shore-based system pre-transmits subsequent highly dependent instructions along with the status parameter verification boundary to the ship's buffer area. The status parameters include speed, rudder angle, heading angle, and distance to surrounding obstacles. After receiving the completion confirmation signal, the system triggers the execution of subsequent highly dependent instructions in the buffer area.

[0091] Furthermore, in S300, the state parameter verification boundary includes:

[0092] The valid range of values ​​for status parameters related to the execution of subsequent strongly dependent instructions;

[0093] The maximum allowable change in the status parameter between the pre-transmission time and the trigger execution time, i.e., the preset change threshold;

[0094] The state parameter verification boundary is determined by the shore-based system based on the ship's state at the pre-transmission time, and is transmitted to the ship's buffer along with subsequent strongly dependent instructions.

[0095] Specifically, upon receiving the intermediate progress confirmation signal, the shore-based system immediately initiates the pre-transmission process for subsequent strongly dependent instructions. The pre-transmission includes the subsequent strongly dependent instructions themselves and the status parameter verification boundaries bound to them, both of which are transmitted as a single data packet to the ship's buffer.

[0096] The state parameter verification boundary is determined by the shore-based system at the pre-transmission time based on the current ship state, covering four types of state parameters related to the execution of subsequent strongly dependent commands: speed , rudder angle Bow angle and distance to surrounding obstacles For each type of state parameter, the validation boundary includes two constraints: one is the valid value range. ,in This is the minimum allowed value for this state parameter. The maximum allowed value of this state parameter, together with the value of the other two, constitutes the absolute range of values ​​allowed for this parameter when subsequent strongly dependent commands can be safely executed. This range is determined by the shore-based system based on the ship's current maneuverability, navigation environment, and command execution requirements. When the current value of the state parameter falls within... Within the specified range, it indicates that the ship's status meets the prerequisites for the safe execution of subsequent highly dependent commands; outside this range, it indicates that the ship's status has deviated from the safety boundary, and subsequent highly dependent commands should not be triggered. Secondly, there is a preset change threshold. This represents the maximum allowable change in this parameter from the pre-transmission time to the trigger execution time. It is used to detect whether the ship's state undergoes unexpected drift during the waiting period for triggering. It is determined by the shore-based system based on the parameter value at the pre-transmission time and the command's requirements for state stability. The above verification boundary is written into the ship's buffer along with subsequent strongly dependent commands for use in compliance verification within the S400 system.

[0097] After receiving the completion confirmation signal, the shore-based system sends a trigger command to the ship's buffer area, activating the execution of subsequent strongly dependent commands in the buffer area. Since the subsequent strongly dependent commands have already arrived at the ship's end and completed their readiness preparations when the intermediate progress confirmation signal triggers pre-transmission, they can immediately enter the execution state after the trigger command arrives. This eliminates the execution delay caused by transmission latency of strongly dependent commands and ensures seamless connection between subsequent strongly dependent commands after the current command is completed.

[0098] S400: During the waiting period for subsequent strongly dependent instructions, the ship continuously collects the ship's current status parameters. When the deviation between the current value of any status parameter and the corresponding value at the pre-transmission time exceeds the preset change threshold, the compliance check between the current status parameter and the status parameter verification boundary is triggered. If the check fails, the cached instructions are invalidated and a failure notification is returned to the shore.

[0099] Specifically, after subsequent highly dependent commands enter the ship's buffer area, the ship continuously collects speed data while waiting for a completion confirmation signal to trigger execution. , rudder angle Bow angle and distance to surrounding obstacles The current values ​​of the four types of state parameters are recorded and compared in real time with the parameter values ​​corresponding to the pre-transmission time. If the deviation between the current value of any state parameter and the value corresponding to the pre-transmission time exceeds a preset change threshold transmitted with the instruction in S300... When this occurs, the compliance verification process is triggered.

[0100] Furthermore, in S400, the compliance verification includes:

[0101] When the current value of any of the aforementioned state parameters exceeds the valid value range, the verification is determined to be unsuccessful, the cache instruction is set to invalid, and a failure notification is returned to the shore base.

[0102] When the current value of any of the aforementioned state parameters does not exceed the valid value range, but the difference between the current value and the parameter value corresponding to the pre-transmission time exceeds the preset change threshold, the verification is determined to be unsuccessful, the cache instruction is set to invalid, and a failure notification is returned to the shore base.

[0103] Specifically, the compliance verification performs the following two-level judgment on the four types of status parameters in sequence:

[0104] First, determine whether the current value exceeds the valid value range. ,in The current values ​​of the state parameters continuously collected by the ship during the waiting period for subsequent strongly dependent instructions to be triggered, if the current value of any state parameter satisfies or If the verification fails, it indicates that the ship's current state has deviated from the absolute boundary where subsequent strongly dependent instructions can be safely executed, and the cached instructions are invalidated.

[0105] If the current values ​​of all state parameters are within the valid range, then the current values ​​are further compared with the parameter values ​​corresponding to the pre-transmission time. Whether the difference exceeds the preset change threshold, i.e., whether it meets the requirement. If any state parameter meets the condition, the verification is deemed to have failed. This indicates that although the ship's state has not exceeded the absolute safety boundary, the change range during the waiting period has exceeded the expected range of the shore-based pre-transmission time. The execution conditions of subsequent strongly dependent instructions deviate significantly from the pre-transmission time, and the cached instructions are also set to invalid.

[0106] If both levels of checks pass, the verification is successful, the cached instructions remain valid, and execution will be triggered normally once the completion confirmation signal arrives.

[0107] When the verification fails, the ship will invalidate the cached instructions and immediately return a failure notification to the shore. The failure notification carries the instruction identifier, the time of failure, the type of status parameter that triggered the verification failure and its current value, so that the shore can determine the cause of the failure and reschedule the issuance of subsequent instructions.

[0108] S500: When the execution confirmation signal fails to advance in stages within the expected time window, it distinguishes between two causes: actuator abnormality and channel interruption, and adopts a differentiated recovery strategy.

[0109] Specifically, the shore-based approach is based on the expected execution duration. The system includes transmission delays at each stage, sets expected time windows for start confirmation signals, intermediate progress confirmation signals, and completion confirmation signals, continuously monitors the arrival status of various execution confirmation signals, and initiates an anomaly judgment process when any execution confirmation signal fails to arrive within the corresponding time window.

[0110] The shore-based system continuously sends heartbeat detection signals to the ship and monitors their response status to determine if the communication link is normal. The heartbeat detection signals and command transmissions share the same wireless channel. When the heartbeat response is normal but the execution confirmation signal does not arrive in stages within the expected time window, it is determined that the actuator is abnormal. The shore-based system immediately suspends the transmission of all pending commands to the ship and sends a pause command to the ship to prevent subsequent highly dependent commands that are ready in the buffer from being triggered unexpectedly. The ship returns an abnormality notification to the shore-based system, carrying the abnormal command identifier, the time of the abnormality, and the last known execution progress. Based on this, the shore-based system replans and reissues subsequent commands. After receiving the new commands, the ship resumes the normal transmission process.

[0111] When the heartbeat response and execution confirmation signal synchronization is interrupted, it is determined that the channel is interrupted. The shore-based system records the type of the last received execution confirmation signal and its arrival time. When the heartbeat response is received again, it is determined that the channel has been restored. The shore-based system then requests an execution progress snapshot from the ship. The snapshot includes the actual execution progress of the current instruction, the current values ​​of each status parameter, and the current status of the instruction in the ship's buffer. The shore-based system determines the starting instruction for resuming transmission based on the snapshot and the dependency relationship between subsequent strongly dependent instructions: if the current instruction has been completed and the subsequent strongly dependent instruction has been triggered, transmission is resumed from the subsequent instruction; if the current instruction has not yet been completed, the dynamic trigger threshold is recalculated based on the actual execution progress and the progress monitoring process continues; if the current instruction has been completed but the subsequent strongly dependent instruction has not been triggered due to buffer invalidation or verification failure, transmission is re-initiated from the subsequent strongly dependent instruction, thereby avoiding duplicate or missed execution of instructions.

[0112] This embodiment utilizes a mechanism for calculating expected execution time and determining dynamic trigger thresholds to advance the pre-transmission of subsequent highly dependent instructions to the current instruction execution process, eliminating the complete channel round-trip delay caused by waiting for completion confirmation signals in traditional methods. Through pre-transmission of state parameter verification boundaries with instructions and continuous compliance verification at the ship's end, cached instructions are proactively invalidated and the shore-based system is notified when the ship's state deviates unexpectedly, intercepting execution safety risks before instruction triggering. Differential identification and recovery strategies for actuator anomalies and channel interruptions ensure that the transmission process resumes from the correct node in abnormal situations. These three mechanisms work synergistically to improve the execution security of remote control while ensuring the timeliness of highly dependent instruction connections.

[0113] Example 2: When a container ship is passing through the deep-water channel of the Yangtze River estuary, it is affected by strong swells. The shore-based remote control center needs to implement continuous directional control. The deceleration command and the subsequent turning command are strongly dependent on each other. The execution parameters of the turning command need to be based on the actual speed after the deceleration command is completed. Moreover, the turning command must be executed within 15 seconds after the deceleration is completed. Otherwise, the ship will deviate from the centerline of the channel and exceed the safe range under the current speed. Therefore, the digital information transmission method in the remote interaction of ships of this invention is used to transmit and manage the above-mentioned continuous control commands.

[0114] The forward transmission delay between the shore base and the ship at that time The reverse transmission delay is 3.2 seconds. The ship-side cache readiness time is 3.0 seconds. The time is 0.8 seconds. The ship's current speed is 12 knots, the rudder angle deviation is 8°, and the sea state is level 4. The base execution time of the deceleration command is retrieved from the preset command template library. The expected execution time was 40 seconds, after corrections for speed, rudder angle deviation, and sea state level. The time is 52 seconds. The dynamic trigger threshold is calculated based on the above parameters:

[0115] ;

[0116] Considering the upper limit of channel delay fluctuation corresponding to the current sea state level 4 It takes 4.8 seconds. Alternative The corrected dynamic trigger threshold is obtained by recalculation:

[0117] ;

[0118] That is, after the sea state is corrected, the triggering time is brought forward from 86% to 83% of the execution progress. The advance corresponds to an execution time of about 1.6 seconds. In safety-critical scenarios, this advance directly determines whether the pre-transmission can still ensure that the turning command is ready on time when the channel latency reaches the upper limit.

[0119] When the deceleration command execution progress reaches 83%, the ship sends an intermediate progress confirmation signal to the shore. Upon receiving the signal, the shore immediately pre-transmits the turning command along with the status parameter verification boundary to the ship's buffer area. The valid speed range in the verification boundary is set to... Section, preset change threshold Set to 1.5 knots, effective range of rudder angle values ​​is set to Preset change threshold Set to 5°, with a preset threshold for bow angle variation. The angle is set to 3°, and the lower limit of the effective range for the distance to surrounding obstacles is set to 500 meters.

[0120] After the deceleration command was executed, the shore-based system received a completion confirmation signal and sent a trigger command to the ship. Since the turning command was already prepared in the ship's buffer zone, the interval between the completion of the deceleration command and the initiation of the turning command was only 1.2 seconds. During the waiting period, the ship continuously monitored the status parameters, detecting a decrease in speed from 8.5 knots at the pre-transmission time to 7.2 knots, a change of 1.3 knots, which did not exceed [a certain threshold]. The bow angle change of 2.1° did not exceed All parameters are within the verification boundaries, the compliance verification is passed, and the cache instructions remain valid.

[0121] To visually demonstrate the technical effects of this invention, the execution timing of the deceleration and steering commands is compared using the connection process as an example. In the traditional remote control method, the shore-based system initiates the transmission of the steering command only after receiving the completion confirmation signal of the deceleration command. Under sea state 4, based on the upper limit of channel delay, it takes 3.0 seconds for the completion confirmation signal to return to the shore, 4.8 seconds for the steering command to be sent to the ship, and 0.8 seconds for the ship's buffer to be ready. These three times, when added together, result in a delay of 8.6 seconds between the completion of the deceleration command and the execution of the steering command, accounting for 57% of the 15-second safety window. This poses a risk of exceeding the safety window when channel delay fluctuates further. Furthermore, the traditional method lacks real-time compliance verification of ship status parameters, and will still force the execution of subsequent commands even when the ship's status deviates significantly, posing a safety hazard. In the method of this invention, the interval between the completion of the deceleration command and the initiation of the steering command is only 1.2 seconds. A comparison of key indicators between the two methods is shown in Table 1.

[0122] Table 1. Method Comparison Table

[0123]

[0124] This invention reduces the latency of highly dependent commands from 8.6 seconds to 1.2 seconds through a pre-transmission mechanism. At the same time, it actively invalidates cached commands when the ship's state deviates unexpectedly through a state parameter compliance verification mechanism, effectively ensuring the safety of ship maneuvering through narrow channels in strong swells and high-latency volatile sea conditions.

[0125] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for digital information transmission in remote interaction with a ship, characterized in that, include: S100: Based on the current control command type, the ship's current speed, rudder angle deviation, and sea state level, calculate the expected execution time of the control command, and determine the dynamic trigger threshold of the intermediate progress confirmation signal based on the transmission delay of subsequent highly dependent commands and the channel delay fluctuation range corresponding to the current sea state level. S200: After sending the control command to the ship, the ship-side actuators sequentially return execution confirmation signals to the shore according to the execution progress, including a start confirmation signal, an intermediate progress confirmation signal, and a completion confirmation signal; wherein the intermediate progress confirmation signal is issued when the execution progress reaches the dynamic triggering threshold. S300: After receiving the intermediate progress confirmation signal, the shore-based system pre-transmits subsequent highly dependent instructions along with the status parameter verification boundary to the ship's buffer area. The status parameters include speed, rudder angle, heading angle, and distance to surrounding obstacles. After receiving the completion confirmation signal, the system triggers the execution of subsequent highly dependent instructions in the buffer area. S400: During the waiting period for subsequent strongly dependent instructions, the ship continuously collects the ship's current status parameters. When the deviation between the current value of any status parameter and the corresponding value at the pre-transmission time exceeds the preset change threshold, the compliance check between the current status parameter and the status parameter verification boundary is triggered. If the check fails, the cached instructions are invalidated and a failure notification is returned to the shore. S500: When the execution confirmation signal fails to advance in stages within the expected time window, it distinguishes between two causes: actuator abnormality and channel interruption, and adopts a differentiated recovery strategy.

2. The method for digital information transmission in remote interaction with a ship according to claim 1, characterized in that, In S100, the calculation of the expected execution time includes: Retrieve the base execution time corresponding to the current control command type from the preset command template library; The base execution time is corrected using the ship's current speed, the difference between the current rudder angle and the target rudder angle, and the sea state level as correction factors to obtain the expected execution time.

3. The digital information transmission method in remote ship interaction according to claim 2, characterized in that, In S100, the construction of the preset instruction template library includes: Collect the actual execution time of each control command type in historical control tasks; The deviation between the actual execution time and the base execution time is calculated. When the number of deviations for the same control instruction type exceeds the preset deviation threshold, the corresponding base execution time is updated with the statistical average of the actual execution time, and the updated base execution time is stored in the preset instruction template library.

4. The digital information transmission method in remote ship communication according to claim 1, characterized in that, The subsequent strongly dependent instruction is a subsequent instruction that satisfies any of the following conditions: The object to which the subsequent instruction is executed has a direct mechanical transmission or pipeline connection with the object to which the current instruction is executed; The execution parameters for subsequent instructions are based on the execution result of the current instruction; Subsequent instructions must be executed within a preset time window after the current instruction is completed; otherwise, the ship's status will deviate from the safe operating range.

5. The digital information transmission method in remote ship communication according to claim 1, characterized in that, In S100, determining the dynamic trigger threshold includes: The forward transmission delay required to transmit subsequent strongly dependent commands from the shore to the ship, and the reverse transmission delay required to complete the confirmation signal from the ship back to the shore; The dynamic trigger threshold is determined by the ratio of the expected execution time minus the sum of the forward transmission delay, the reverse transmission delay, and the ship's end cache instruction readiness time, to the expected execution time.

6. The digital information transmission method in remote ship interaction according to claim 5, characterized in that, In S100, the dynamic trigger threshold is further adjusted according to the current sea state level, including: Obtain the channel delay fluctuation range corresponding to the current sea state level, replace the forward transmission delay with the upper limit of the channel delay fluctuation range, recalculate the dynamic trigger threshold, and use it as the corrected dynamic trigger threshold under the current sea state. When the actual forward transmission delay is detected to exceed the channel delay fluctuation range before the pre-transmission is executed, the dynamic trigger threshold is recalculated by replacing the forward transmission delay with the actual forward transmission delay, and the updated dynamic trigger threshold is synchronized to the ship end. After receiving the updated dynamic trigger threshold, the ship reassesses whether the pretransmission can arrive before the expected completion time of the current instruction. If it cannot arrive, the current pretransmission process is terminated and the shore is notified.

7. The digital information transmission method in remote ship communication according to claim 1, characterized in that, In S300, the state parameter verification boundary includes: The valid range of values ​​for status parameters related to the execution of subsequent strongly dependent instructions; The maximum allowable change in the status parameter between the pre-transmission time and the trigger execution time, i.e., the preset change threshold; The state parameter verification boundary is determined by the shore-based system based on the ship's state at the pre-transmission time, and is transmitted to the ship's buffer along with subsequent strongly dependent instructions.

8. The digital information transmission method in remote ship communication according to claim 7, characterized in that, In S400, the compliance verification includes: When the current value of any of the aforementioned state parameters exceeds the valid value range, the verification is determined to be unsuccessful, the cache instruction is set to invalid, and a failure notification is returned to the shore base. When the current value of any of the aforementioned state parameters does not exceed the valid value range, but the difference between the current value and the parameter value corresponding to the pre-transmission time exceeds the preset change threshold, the verification is determined to be unsuccessful, the cache instruction is set to invalid, and a failure notification is returned to the shore base.

9. The digital information transmission method in remote ship communication according to claim 1, characterized in that, In S500, the differentiated recovery strategy specifically includes: When the communication link between the shore base and the ship remains normal but the execution confirmation signal does not advance in stages, it is determined that the actuator is abnormal; Suspend all pending command transmissions from shore to ship and return an exception notification to shore containing the exception command identifier, the time of the exception, and the last known execution progress, and resume transmission after shore reissues the command; When the communication link between the shore base and the ship is interrupted and the confirmation signal synchronization is interrupted, it is determined as a channel interruption; Record the type and time of the last received execution confirmation signal. After the channel is restored, request a snapshot of the current execution progress from the ship. Determine the starting instruction for resuming transmission based on the dependency relationship between the execution progress snapshot and subsequent strongly dependent instructions.

10. The digital information transmission method in remote ship communication according to claim 9, characterized in that, The step of determining the starting instruction for resuming transmission based on the dependency relationship between the execution progress snapshot and subsequent strongly dependent instructions specifically includes: If the current instruction has been completed and a subsequent strongly dependent instruction has been triggered and executed, then the transmission resumes from the instruction following the strongly dependent instruction. If the current instruction has not yet been completed, the dynamic trigger threshold will be recalculated based on the actual execution progress in the execution progress snapshot and the progress monitoring process will continue. If the current instruction has been completed but subsequent strongly dependent instructions have not been triggered due to cache invalidation or verification failure, the transmission is re-initiated from the subsequent strongly dependent instructions, thereby avoiding repeated or missed execution of instructions.

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