Emergency control method and system for satellite communication robot dog

Abstract

The invention belongs to the technical field of robot control, and particularly relates to an emergency control method and system for a satellite communication robot dog, and the method comprises the steps: obtaining the round-trip time delay of a robot dog data package and an effective data package proportion, and constructing a feature vector; calculating a link degradation index according to a deviation condition between the feature vector and the high-quality cluster; calculating a control authority level according to the link degradation index; according to the control authority level and the effective data packet rate, obtaining instruction redundancy; and repeatedly sending the instruction data packet according to the instruction redundancy, and discarding the repeated instruction by the receiving end through the instruction ID so as to control the robot dog. According to the method, the link quality is dynamically evaluated and the instruction redundancy is adjusted, so that the reliable execution of the emergency instruction when the satellite link quality is poor is ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of robot control. More particularly, the present application relates to an emergency control method and system for a satellite communication robot dog. BACKGROUND

[0002] In special application scenarios such as emergency rescue, post-disaster exploration, and high-risk environment inspection, intelligent robots such as robot dogs are playing an increasingly important role. These tasks often require robot dogs to penetrate into areas that are difficult for humans to reach or where there is a high degree of danger, and remote control of the robot dog becomes a key to ensuring task execution and operator safety. In wide or remote areas, ground communication facilities are often destroyed or cannot be covered, and satellite links become necessary, even the only means of communication for remote control.

[0003] However, satellite links themselves have high latency characteristics, and it usually takes several seconds for signals to travel back and forth between ground stations, satellites, and remote robot dogs. This round-trip latency directly results in the inability of operators' instructions to reach the robot dog instantaneously; at the same time, the stability of satellite links is extremely susceptible to atmospheric environment, weather changes, terrain obstructions, and electromagnetic interference, and other environmental factors, which can cause severe fluctuations in communication quality, resulting in a sharp decline in the proportion of effective data packets, and serious packet loss.

[0004] In related technologies, many teleoperation control systems, when designed, assume that the communication link is relatively reliable and stable, and often use fixed communication protocols and instruction sending strategies, lacking real-time and dynamic perception and adaptation to communication link quality. When the quality of the satellite link suddenly deteriorates, the fixed and non-redundant instruction sending mechanism cannot guarantee the reliable delivery of critical instructions such as emergency stop, and there is a risk of robot dog out of control. Secondly, the control interface lacks perception of the link state, and when the link latency and jitter are extremely large, high-risk instructions are delayed, out of order, or discarded due to link problems, causing the robot dog to perform dangerous actions. SUMMARY

[0005] To solve the above technical problems of using a fixed control strategy, being unable to evaluate the satellite link state in real time, and causing critical instructions to be lost when the link quality is poor, and thus high-risk operations, the present application provides solutions in the following aspects.

[0006] In a first aspect, the application provides an emergency control method for a satellite communication robot dog, comprising: obtaining round-trip time delay of data packets received by the robot dog in a time window and a proportion of valid data packets, and constructing a feature vector according to the average round-trip time delay, the time delay jitter and the valid data packet rate; the average round-trip time delay is the mean of the round-trip time delay in the time window, the time delay jitter is the standard deviation of the round-trip time delay in the time window, and the valid data packet rate is the proportion of valid data packets in the time window; obtaining a set of standard feature vectors collected in an ideal environment as a high-quality cluster; obtaining a link degradation index according to the distance between the feature vector and the centroid of the high-quality cluster; obtaining a control authority level according to the link degradation index; obtaining an instruction redundancy according to the control authority level and the valid data packet rate; assigning a unique ID to the control instruction, and repeatedly sending the instruction data packet carrying the unique ID according to the instruction redundancy; the robot dog receiving end compares the unique ID with the ID of the received instruction to discard the repeated instruction data packet, and executes the instruction in the non-repeated instruction data packet to control the robot dog.

[0007] The application can real-time evaluate the unstable satellite link quality, and dynamically adjust the control strategy according to the link quality, ensure the instruction reliability when the link quality is poor by redundant sending, and realize the stable and reliable control of the robot dog in the complex emergency scene, while ensuring the low time delay operation.

[0008] Preferably, the feature vector is constructed according to the average round-trip time delay, the time delay jitter and the valid data packet rate, comprising: normalizing the average round-trip time delay, the time delay jitter and the valid data packet rate respectively, and combining the normalized average round-trip time delay, the time delay jitter and the valid data packet rate into the feature vector.

[0009] Preferably, the normalization is maximum-minimum value normalization.

[0010] Preferably, the set of standard feature vectors collected in an ideal environment is obtained as a high-quality cluster, comprising: executing a calibration program in an open and unobstructed ideal environment of satellite signals to obtain a set of feature vectors of the robot dog in 10 minutes in the environment as a high-quality cluster.

[0011] This invention provides an objective and stable benchmark for link quality assessment by performing a calibration procedure in an open, unobstructed ideal environment and collecting feature vectors for a specific duration as high-quality clusters. The high-quality clusters represent the performance of the robot dog under optimal communication conditions. Subsequently, by calculating the deviation of the real-time feature vectors from this benchmark, the degree of degradation of the current link relative to the ideal state can be accurately reflected, providing a reliable basis for calculating the link degradation index, enhancing the accuracy of the assessment results, and providing a certain foundation for emergency control of the robot dog.

[0012] Preferably, the link degradation index satisfies the following relationship: In the formula, for Link degradation index at any given moment. for The normalized value of the average round-trip time at time 1. for The normalized value of the time delay jitter at any given moment. for Effective data packet rate at any given time For the average round-trip time in the center of mass of a high-quality cluster, For high-quality cluster core latency jitter, For high-quality cluster centroids, the effective data packet rate, , and These are the weighting factors for average round-trip time, latency jitter, and effective data packet rate, respectively.

[0013] This invention calculates the link degradation index using a weighted Euclidean distance formula, which integrates the differences between average round-trip time, latency jitter, effective data packet rate, and high-quality cluster centroid. Furthermore, it uses weighting factors to differentiate the threat level of emergency control for machine dogs based on different indicators. This allows the link degradation index to not only reflect the overall deviation of the communication link but also highlight the deterioration of key performance indicators, thereby more accurately assessing the link status.

[0014] Preferably, the control permission levels satisfy the following relationship: In the formula, for Real-time control access levels for Link degradation index at any given moment. To preset the maximum link degradation index, It is a function with maximum value. For sensitivity factor, It is a very small positive number.

[0015] The application calculates the control authority level by using the link degradation index, the maximum link degradation index and the sensitivity factor, ensures that when the link quality is slightly degraded, the authority level slowly decreases, and when the degradation index approaches the maximum value, the authority level rapidly decreases, and the nonlinear response meets the sensitivity requirement of risk in emergency control; meanwhile, the minimum positive number is set to ensure the bottom line of the authority level, prevents the system authority from being completely invalid, and enhances the robustness of the control system.

[0016] Preferably, the instruction redundancy satisfies the relationship: ; in the formula, is the instruction redundancy at the moment, is the control authority level at the moment, is the effective data packet rate at the moment, is the effective data packet rate at the moment, is the effective data packet rate at the moment, is the effective data packet rate at the moment, is the effective data packet rate at the moment,

[0017] The application calculates the instruction redundancy according to the control authority level and the effective data packet rate, inversely deduces the instruction redundancy based on the probability of data packet failure and the tolerance of the system to failure by using the logarithmic relationship, ensures that when the link quality is worse and the authority level is lower, the number of repeated sending of the instruction is higher. The high packet loss rate can be effectively resisted, the delivery probability of the key instruction under the low-quality link is ensured with the minimum communication cost, and the reliable execution of the emergency control is ensured.

[0018] Preferably, the instruction redundancy is 1 when the effective data packet rate is 1 or 0.

[0019] Preferably, the robot dog receiving end compares the unique ID with the ID of the received instruction to discard the repeated instruction data packet, and the robot dog receiving end compares the ID of the newly received instruction data packet with the ID of the last executed instruction stored locally; if the ID of the newly received instruction data packet is greater than the local ID, the new instruction is executed and the local ID is updated; if the ID of the newly received instruction data packet is less than or equal to the local ID, the newly received instruction data packet is discarded.

[0020] In the second aspect, the application provides an emergency control system of a satellite communication robot dog, which comprises a processor and a memory, and the memory stores computer program instructions, and when the computer program instructions are executed by the processor, the above-mentioned emergency control method of the satellite communication robot dog is realized.

[0021] By adopting the technical scheme, the computer program of the emergency control method of the satellite communication robot dog is generated and stored in the memory to be loaded and executed by the processor, so that the terminal equipment is manufactured according to the memory and the processor, and use is facilitated.

[0022] The application has the advantages that: the application realizes comprehensive real-time evaluation of the satellite communication link state by constructing a feature vector, and overcomes one-sidedness of single index evaluation; by introducing a high-quality cluster calibrated in an ideal environment as a reference benchmark, a link degradation index of the current link compared with the best state can be calculated, providing more accurate and more contrastive basis for subsequent decision-making; the application maps the link degradation index to a control authority level, when the link quality decreases, the operator can be actively restricted to execute high-risk or high-bandwidth instructions, thereby avoiding control risks caused by instruction delay or loss from the source; secondly, according to the current effective packet rate and the control authority level, the required instruction redundancy to ensure instruction delivery is reversely deduced, the sending number of key instructions is automatically increased when the link quality is poor, thereby resisting high packet loss rate and ensuring the final reliable delivery of instructions, and realizing emergency control of the robot dog. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a flowchart schematically showing an emergency control method of a satellite communication robot dog in the application; Figure 2 is a schematic diagram of delay and effective packet rate; Figure 3 is a schematic diagram of control authority level; Figure 4 is a schematic diagram of instruction redundancy. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are some but not all of the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the application.

[0025] The specific embodiments of the application will be described in detail below with reference to the drawings.

[0026] The embodiments of the application disclose an emergency control method of a satellite communication robot dog, referring to Figure 1 , comprising steps S1-S5: S1, constructing a feature vector according to the round-trip delay of the data packet received by the robot dog and the effective packet ratio.

[0027] Specifically, a time window is set, round-trip delays of data packets received by the robot dog in the time window are obtained, a mean value of the round-trip delays in the time window is taken as an average round-trip delay, a standard deviation of the round-trip delays in the time window is taken as a delay jitter, and a proportion of valid data packets received by the robot dog in the time window is taken as a valid data packet rate.

[0028] Exemplarily, the length of the time window is 1 second.

[0029] Further, each value in the feature vector is normalized by a historical running boundary of the robot dog system, and the normalized values are combined into the feature vector, for example, the historical running boundary of the average round-trip delay is 0.4 seconds and 2 seconds, and the average round-trip delay is normalized by taking 2 seconds and 0.4 seconds as the maximum value and the minimum value.

[0030] In one embodiment, the feature vector satisfies the relationship: ; In the formula, is the feature vector at the moment, is a normalized value of the average round-trip delay at the moment, is a normalized value of the delay jitter at the moment, is the valid data packet rate at the moment.

[0031] wherein, reflects the average time from the control center issuing an instruction to the robot dog receiving an acknowledgement, reflects the stability of the satellite link, reflects the bandwidth and packet loss of the link, and the multi-dimensional data features can comprehensively measure the state of the satellite link at the moment .

[0032] S2, calculating a link degradation index according to the deviation of the feature vector from the high-quality cluster.

[0033] It should be noted that when the robot dog is in different use environments, the corresponding feature vectors will also be different, for example, the average round-trip delay in a signal shielding environment is larger than that in an open and unshielded environment, and the feature vectors in different environments will also be different, therefore, the present application calculates a link degradation index according to the deviation of the feature vector from the high-quality cluster.

[0034] ​​​​Specifically, before deploying the robot dog, a calibration procedure is performed in an ideal environment with open, unobstructed satellite signals to obtain the robot dog's feature vectors within 10 minutes under this environment. The feature vectors collected under this environment are used as standard feature vectors, and the set of standard feature vectors is used as high-quality clusters. The link degradation index is obtained based on the distance between the feature vectors collected in real time during emergency control and the centroid of the high-quality clusters. The time length for collecting feature vectors is a preset value, and the implementers can determine the time length for collecting feature vectors according to the actual situation.

[0035] In one embodiment, the link degradation index satisfies the following relationship: ; In the formula, for Link degradation index at any given moment. for The normalized value of the average round-trip time at time 1. for The normalized value of the time delay jitter at any given moment. for Effective data packet rate at any given time For the average round-trip time in the center of mass of a high-quality cluster, For high-quality cluster center latency jitter, For high-quality cluster centroids, the effective data packet rate, , and These are weighting factors for average round-trip time, latency jitter, and effective data packet rate, respectively, in this embodiment. It is 0.5. It is 0.2. The weight is set to 0.3, and the implementers can determine the weighting factor based on the actual situation.

[0036] It's easy to understand that the centroid of the high-quality cluster represents the ideal communication state of the robot dog. The greater the difference between the robot dog's real-time feature vector and the centroid of the high-quality cluster, the further the robot dog's real-time communication state deviates from the ideal communication state, and the more likely the robot dog's communication link is to be interfered with, resulting in a larger link degradation index. Conversely, the smaller the difference between the robot dog's real-time feature vector and the centroid of the high-quality cluster, the closer the robot dog's real-time communication state is to the ideal communication state, resulting in a smaller link degradation index. Furthermore, the deviation of different indicators in the feature vector poses different threats to the robot dog's emergency control when the robot dog is used in different application scenarios. Therefore, the influence of different indicators in the feature vector on the link degradation index is adjusted by weighting factors.

[0037] S3. Calculate the control permission level based on the link degradation index.

[0038] To combine link quality assessment with remote operation control, this invention calculates the control authority level based on the link degradation index, thereby restricting the types of instructions that the operator can send when the control authority level is low, thus avoiding high-risk operations from the source.

[0039] Specifically, the control permission level is obtained based on the real-time link degradation index and the preset maximum link degradation index. The human-machine interface used by the operator dynamically adapts its functions according to the obtained control permission level. The preset maximum link degradation index is 0.8, and the implementers can determine this value according to the actual situation.

[0040] For example, the trajectory planning tool on the human-machine interface is activated and available to the operator only when the control permission level is greater than a preset threshold (e.g., 0.8); when the control permission level is lower than a safety threshold (e.g., 0.3), the human-machine interface will be automatically locked, and only low-bandwidth, high-robust instruction buttons such as safety warnings will be displayed to the operator.

[0041] In one embodiment, the control permission levels satisfy the following relationship: ; In the formula, for Real-time control access levels for Link degradation index at any given moment. To preset the maximum link degradation index, It is a function with maximum value. For sensitivity factor, It is a very small positive number, in this embodiment It is 2. The value is 0.01, and the implementers can adjust it according to the actual situation. and The value of .

[0042] Among them, the link degradation index A higher value indicates a lower level of control authority, thus limiting high-risk operations by the robot dog due to command delays when communication functions are restricted; Link Degradation Index The smaller the value, the higher the control level. Under good communication conditions, the operator's instructions can be transmitted to the robot dog in a timely manner, so a higher control level should be given.

[0043] S4. Calculate instruction redundancy based on control authority level and package and send it to the robot dog.

[0044] It should be noted that the control authority level not only represents the operation authority, but also is a direct inversion of the link quality calculated in the previous step. When the control authority level is lower, it indicates that the link quality is worse, and the probability of data packet loss is higher. In the emergency teleoperation scene, the loss of critical instructions is unacceptable. Therefore, the application uses instruction redundancy to resist high packet loss rate. By controlling the authority level, the number of repeated transmissions required for the instruction is inversely calculated, so that the lower the control authority level, the worse the link, the higher the instruction redundancy, so as to improve the probability of successful reception of the instruction packet and ensure the final reliable execution of the emergency instruction.

[0045] Specifically, when the human-machine interface of the operator is not locked, the instruction redundancy is obtained according to the control authority level and the effective data packet rate in the feature vector , the operator's operation instruction is repeatedly transmitted through the satellite link .

[0046] In one embodiment, the instruction redundancy satisfies the relationship: ; In the formula, is the instruction redundancy at the moment, is the control authority level at the moment, is the effective data packet rate at the moment, is the upward rounding function.

[0047] Wherein, is the probability of data packet transmission failure at the moment, then the probability that all of the times of continuous data packet transmission fail is , and , when is higher, it indicates that the operator is in a high authority state, allowing the operator to send fine control instructions to the robot dog, and the communication link of the robot dog is good. At this time, the tolerance of the operator instruction transmission failure is also higher, so that the robot dog can receive the control instruction without additional redundant data packets; when is lower, the robot dog control system is in a dangerous, low-authority emergency state, and the tolerance of the instruction transmission failure is lower at this time. Therefore, the is the highest probability of all data packet transmission failures that can be tolerated, so that is obtained by mathematical relationship conversion , and is obtained.Since the number of data packet transmissions is an integer, the is taken as the instruction redundancy, representing the number of repeated transmissions of the instruction data packet.​​

[0048] Need to be added, the effective data packet rate 1, the instruction data will be received by the robot dog, at this time, send 1 instruction data packet can, the effective data packet rate 0, at this time, no matter how many times the instruction data packet is sent will not be received by the robot dog, at this time, also send 1 instruction data packet can, therefore, in 1, and 0, the instruction redundancy is 1, avoid waste of communication resources.

[0049] Exemplarily, Figure 2 The delay and the effective data packet rate schematic diagram, Figure 3 The control authority level schematic diagram, Figure 4 The instruction redundancy schematic diagram, from the figure, when the average round trip delay and delay jitter rise, the effective data packet rate decreases, the control authority level will also decrease, and then cause the instruction redundancy to rise, thereby realizing the dynamic adjustment of the number of times of sending operation instruction.

[0050] S5, according to the instruction redundancy to the robot dog sends instruction data packet to realize the robot dog control.

[0051] Specifically, in the sending end, each control instruction is allocated a unique ID. The sending end sends the instruction data packet with ID to the robot dog Times. When the robot dog receives the new instruction packet, the ID of the received instruction data packet is compared with the ID of the last received instruction data packet: if the new ID is greater than the local ID, the instruction is executed and the local ID is updated; if the new ID is less than or equal to the local ID, it is determined as a repeated instruction, and the repeated instruction is directly discarded, so that when multiple instruction data packets corresponding to the same instruction successfully arrive at the robot dog, the instruction is only executed once, thereby realizing the emergency control of the robot dog.

[0052] The embodiment of the application further discloses an emergency control system of a satellite communication robot dog, comprising a processor and a memory, the memory stores computer program instructions, when the computer program instructions are executed by the processor, the emergency control method of the satellite communication robot dog is realized.

[0053] The above system also includes communication bus and communication interface and other components familiar to those skilled in the art, its setting and function are known in the art, therefore, will not be repeated here.

Claims

1. An emergency control method for a satellite communication robot dog, characterized in that, include: Obtain the round-trip time and the ratio of effective data packets received by the robot dog within the time window, and construct a feature vector based on the average round-trip time, delay jitter, and effective data packet rate; The average round-trip time is the mean of the round-trip time within the time window, the delay jitter is the standard deviation of the round-trip time within the time window, and the effective data packet rate is the proportion of effective data packets within the time window. Obtain a set of standard feature vectors collected under ideal conditions as a high-quality cluster; obtain the link degradation index based on the distance between the feature vectors and the centroids of the high-quality clusters; obtain the control authority level based on the link degradation index; obtain the instruction redundancy based on the control authority level and the effective data packet rate. A unique ID is assigned to each control command, and the command data packet carrying the unique ID is repeatedly sent according to the command redundancy. The receiving end of the robot dog compares the unique ID with the ID of the received command to discard duplicate command data packets and execute the commands in the non-duplicate command data packets, thereby realizing the control of the robot dog.

2. The emergency control method for a satellite communication robot dog according to claim 1, characterized in that, The step of constructing a feature vector based on average round-trip time, latency jitter, and effective data packet rate includes: normalizing the average round-trip time, latency jitter, and effective data packet rate respectively, and combining the normalized average round-trip time, latency jitter, and effective data packet rate into a feature vector.

3. The emergency control method for a satellite communication robot dog according to claim 2, characterized in that, The normalization is the maximum-minimum normalization.

4. The emergency control method for a satellite communication robot dog according to claim 1, characterized in that, The process of obtaining a set of standard feature vectors collected under ideal conditions as a high-quality cluster includes: performing a calibration procedure under an ideal environment with open, unobstructed satellite signals, and obtaining a set of feature vectors of the robot dog within 10 minutes under this environment as a high-quality cluster.

5. The emergency control method for a satellite communication robot dog according to claim 1, characterized in that, The link degradation index satisfies the following relationship: ； In the formula, for Link degradation index at any given moment. for The normalized value of the average round-trip time at time 1. for The normalized value of the time delay jitter at any given moment. for Effective data packet rate at any given time For the average round-trip time in the center of mass of a high-quality cluster, For high-quality cluster center latency jitter, For high-quality cluster centroids, the effective data packet rate, , and These are the weighting factors for average round-trip time, latency jitter, and effective data packet rate, respectively.

6. The emergency control method for a satellite communication robot dog according to claim 1, characterized in that, The control permission levels satisfy the following relationship: ； In the formula, for Real-time control access levels for Link degradation index at any given moment. To preset the maximum link degradation index, It is a function with maximum value. For sensitivity factor, It is a very small positive number.

7. The emergency control method for a satellite communication robot dog according to claim 1, characterized in that, The instruction redundancy satisfies the following relationship: ； In the formula, for Instruction redundancy at any given moment for Real-time control access levels for Effective data packet rate at any given time This is the floor function.

8. The emergency control method for a satellite communication robot dog according to claim 1, characterized in that, The step of obtaining instruction redundancy based on control authority level and effective data packet rate includes: when the effective data packet rate is 1 or 0, the instruction redundancy is 1.

9. The emergency control method for a satellite communication robot dog according to claim 1, characterized in that, The robot dog receiver compares the unique ID with the ID of the received instruction to discard duplicate instruction data packets. This includes: the robot dog receiver comparing the ID of the newly received instruction data packet with the ID of the previously executed instruction stored locally; if the ID of the newly received instruction data packet is greater than the local ID, then the new instruction is executed and the local ID is updated; if the ID of the newly received instruction data packet is less than or equal to the local ID, then the newly received instruction data packet is discarded.

10. An emergency control system for a satellite communication robot dog, characterized in that, include: A processor and a memory, wherein the memory stores computer program instructions that, when executed by the processor, implement an emergency control method for a satellite communication robot dog according to any one of claims 1-9.

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