Data transmission method of vehicle-mounted controller

Abstract

The invention discloses a data transmission method of a vehicle-mounted controller, relates to the technical field of data transmission, and effectively relieves the transmission conflict between OTA upgrade and a real-time control instruction through a multi-dimensional cooperation mechanism. A dynamic bandwidth allocation mechanism based on a vehicle running state breaks through a traditional fixed resource reservation mode, and precise adaptation of channel resources and safety requirements is achieved; performing semantic-level criticality analysis to deeply analyze the underlying logic association of the instruction, and constructing dynamic priority mapping; the fragment recombination and redundancy transmission technology significantly reduces the influence of upgrade interruption on the system, and ensures reliable delivery of key instructions; and the compensation transmission mechanism balances the timely recovery of the security instruction and the transmission efficiency of the non-critical data through a differential strategy.

Description

Technical Field

[0001] The present invention relates to the technical field of data transmission, and in particular to a data transmission method of a vehicle-mounted controller. Background Art

[0002] Modern vehicle-mounted controller networks generally adopt a heterogeneous communication architecture. The CAN bus is responsible for transmitting key control instructions, and Ethernet carries large-volume data such as infotainment. With the popularization of OTA upgrade technology, the transmission of software upgrade packages requires continuous use of a large amount of bandwidth, resulting in traditional network architectures facing resource conflicts between control instructions and upgrade data traffic. In L3 and above smart vehicles, emergency instructions from the autonomous driving module, such as emergency braking signals, must share physical channels with OTA data packets, forming a new type of data transmission conflict scenario.

[0003] To address the above issues, existing systems have adopted solutions such as reserving fixed bandwidth for critical control instructions and implementing traffic shaping through Quality of Service (QoS) policies. The former forcibly reserves some channel resources during OTA upgrades, but cannot dynamically adapt to fluctuations in data volume at different upgrade stages, which can easily lead to idle or insufficient bandwidth; the latter relies on network layer packet marking for priority scheduling and lacks the ability to deeply analyze instruction semantics; when OTA upgrade packages and security control instructions are transmitted concurrently, false high-priority data may occupy the channel.

[0004] Some solutions alleviate conflicts through software solutions such as fragmented transmission of upgrade packages and dynamic priority adjustment. However, they are limited by the rigid design of the in-vehicle network protocol stack. The fundamental reason is that the traditional communication architecture regards control instructions and data services as independent transmission streams, resulting in a structural conflict in resource allocation between OTA upgrade background tasks and real-time vehicle control requirements. Summary of the Invention

[0005] In view of the above existing problems, the present invention is proposed.

[0006] The present invention provides a data transmission method for an on-board controller to solve the problem that traditional on-board networks adopt a heterogeneous communication architecture, which easily causes channel competition between control commands and upgrade data during OTA upgrades, and the fixed bandwidth reservation and QoS strategy have defects such as insufficient dynamic adaptability and lack of semantic recognition, resulting in the risk of delay in emergency command transmission.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0008] An embodiment of the present invention provides a data transmission method of a vehicle-mounted controller, which includes:

[0009] Step S1, when an OTA upgrade request is detected, dynamically allocating the bandwidth ratio of the control instruction transmission channel and the upgrade data transmission channel according to the current vehicle operating state;

[0010] Step S2, performing semantic-level criticality analysis on the vehicle control instructions and generating an instruction transmission priority mapping table;

[0011] Step S3, when the upgrade data packet and the control instruction compete for a channel, triggering a transmission mode switch based on the priority mapping table;

[0012] Step S4, using the data packet fragmentation and reassembly mechanism to process the interrupted upgrade data, retaining the fragment identification and verification information of the interruption point;

[0013] Step S5, continuously monitoring the waiting time of the control instruction queue during the upgrade transmission process, and dynamically adjusting the bandwidth allocation ratio;

[0014] Step S6: When a safety-related instruction is identified, a preset redundant transmission path is activated for parallel data delivery.

[0015] As a preferred solution of the data transmission method of the vehicle-mounted controller described in the present invention, the specific steps of dynamically allocating bandwidth ratios in step S1 include:

[0016] Establishing a mapping relationship table between vehicle operating state parameters and minimum reserved bandwidth, wherein the parameters include vehicle speed, gear position, and autonomous driving mode;

[0017] Correcting the calculation weight of the minimum reserved bandwidth according to the steering wheel angle change rate obtained in real time;

[0018] When it is detected that the brake pedal opening exceeds the threshold, the control command channel bandwidth ratio is forced to increase to more than 80%.

[0019] As a preferred solution of the data transmission method of the vehicle controller described in the present invention, the semantic level criticality analysis method of step S2 includes:

[0020] Parse the DBC definition file of the control instruction and extract the signal source component, data refresh cycle and dependency parameters;

[0021] Constructing an instruction impact assessment model, wherein the model input includes an actuator response delay associated with the instruction and a system safety level;

[0022] Generate a dynamically updated priority mapping table, which includes the instruction ID, the minimum transmission delay requirement, and the upper limit of the allowed retransmission times.

[0023] As a preferred solution of the data transmission method of the vehicle controller described in the present invention, in step S2, the instruction impact evaluation model is constructed as follows:

[0024] The three indicators of actuator response delay, system safety level and signal dependency are integrated to quantitatively evaluate the criticality of each control instruction in the OTA upgrade process. After completion, the discrete priority and related transmission parameters are generated based on the score.

[0025] As a preferred solution of the data transmission method of a vehicle controller described in the present invention, in step S2, the step of performing semantic-level criticality analysis on the vehicle control instructions and generating an instruction transmission priority mapping table includes:

[0026] Combine the indicators in a weighted manner to form an impact score:

[0027] Among them, I i represents the impact score of instruction index i, a represents the executor delay impact weight, Δ r ef represents the reference maximum response delay, Δ i represents the actual response delay of the actuator corresponding to instruction i, b represents the safety level impact weight, S i Indicates the system security level score of instruction i, S max represents the maximum score of the system security level, c represents the dependency impact weight, R i Indicates the number of signal sources that instruction i depends on, R max Indicates the maximum number of dependent signals among all instructions, i indicates the corresponding instruction i;

[0028] Discretize the continuous value of influence into priority level, the formula is:

[0029]

[0030] Among them, P i Indicates the priority level of instruction i, M indicates the total number of preset priority levels,

[0031] represents the maximum impact score obtained among all instruction index j;

[0032] The minimum transmission delay requirement is calculated based on the impact score. The calculation formula is:

[0033] δ i =δ0 / I i , where δ i represents the minimum transmission delay requirement of instruction i, δ0 represents the benchmark transmission delay threshold;

[0034] Calculate the maximum retransmission limit for each instruction:

[0035]

[0036] in, Indicates the maximum number of retransmissions allowed for instruction i, τ slot Indicates the length of the communication time slot;

[0037] After the calculation is completed, the field instruction IDi, the minimum transmission delay δ i , priority P i Maximum number of retransmissions Summarize by instruction index to form a dynamically updated instruction transmission priority mapping table.

[0038] As a preferred solution of the data transmission method of the vehicle controller described in the present invention, the data packet fragmentation and reassembly mechanism in step S4 includes:

[0039] Divide the upgrade data packet into fixed-size transmission units, and append a header containing the fragment sequence number and context association code to each unit;

[0040] When switching channels, the sequence number of the last successfully transmitted fragment is recorded, and a breakpoint information frame containing the identifier of the untransmitted fragment is generated;

[0041] Based on the verification result fed back by the receiving end, the damaged fragment and its two adjacent fragments are selectively retransmitted.

[0042] As a preferred solution of the data transmission method of the vehicle controller described in the present invention, the activation condition of the redundant transmission path in step S6 includes:

[0043] When the control instruction has been waiting in the queue for longer than its associated safety response threshold;

[0044] When the current channel bit error rate is detected to exceed the set threshold for three consecutive sampling cycles;

[0045] The redundant transmission path adopts a combination of heterogeneous channels, including parallel transmission channels of the CAN bus and the vehicle Ethernet.

[0046] As a preferred solution of the data transmission method of the vehicle controller described in the present invention, the method further includes a compensation transmission mechanism:

[0047] After each channel switch, count the number and type of data packets lost due to the switch;

[0048] Selecting a compensation transmission period based on the network load status, wherein the period is determined based on historical traffic fluctuation patterns and real-time remaining bandwidth;

[0049] A preemptive retransmission strategy is used for the compensatory transmission of safety-related instructions, while an idle period compensatory transmission strategy is used for non-safety instructions.

[0050] As a preferred embodiment of the data transmission method for an on-board controller of the present invention, the compensation transmission mechanism adopts two compensation strategies, preemptive and idle period, to ensure that safety-related instructions can be promptly resumed during the OTA upgrade process, while non-safety instructions are retransmitted during the channel idle period. At the same time, cache management and preemption signal generation logic are maintained.

[0051] In the compensation transmission mechanism, a preemption trigger signal for safety-related instructions is defined:

[0052] Calculate the urgency index for the security instruction with instruction index i:

[0053] G i =H(T w,i -T th,i )+H(E err -E th ),

[0054] Among them, G i Represents the preemption trigger signal (binary), H(x) is a unit step function, H(0) = 0, takes 1 when x>0, otherwise takes 0, the dimension of x is the same as T w,i and e err Consistent, T w,i Indicates the cumulative waiting time of instruction i in the queue, T th,i represents the safety response threshold of instruction i, E err Indicates the current channel bit error rate, E th Indicates the bit error rate threshold,

[0055] When G i When ≥1, the corresponding instruction triggers preemptive retransmission;

[0056] All fragments to be retransmitted for this command are immediately pushed into the preemptive cache pool. Cache management uses a double-key sorting method based on command priority and fragment sequence number:

[0057] Press (P i ,-k) in descending order,

[0058] in, is the cache pool set, D i,k Indicates the kth slice data of instruction i, P i is the priority of instruction i in the mapping table. The smaller the sequence number k, the earlier the fragment is generated. Therefore, -k is used to implement first-come-first-served.

[0059] When the buffer overflows , remove the item with the lowest priority and the largest fragment number in the current collection:

[0060]

[0061] To ensure that high-priority shards are retained;

[0062] For non-safety instructions, the idle period retransmission strategy is adopted and the channel utilization is defined as follows:

[0063] U(t)=D active (t) / D cap ,

[0064] Among them, U(t) represents the channel utilization at time t, D active (t) is the current active traffic rate, D cap is the maximum carrying rate of the channel, when U(t) idle When the idle threshold is reached, the system takes out the non-safe fragments from the idle buffer pool and sends them in the order of generation without preemption. Otherwise, it waits for the next idle period. idle Indicates the channel utilization threshold that triggers idle retransmission.

[0065] As a preferred solution of the data transmission method of the vehicle controller described in the present invention, the method includes the following initialization configuration steps before implementation:

[0066] Preload the communication topology diagram of each vehicle controller, which includes the physical connection type and data flow between each node;

[0067] Set the sensitivity coefficient of dynamic bandwidth adjustment, which is configured differently according to the computing resource margin of the vehicle platform;

[0068] An instruction priority conflict arbitration rule base is established, wherein the rule base includes decision logic for priority coverage relationships in different scenarios.

[0069] The beneficial effects of the present invention are as follows: the present invention effectively alleviates the transmission conflict between OTA upgrades and real-time control instructions through a multi-dimensional collaborative mechanism; the dynamic bandwidth allocation mechanism based on the vehicle's operating status breaks through the traditional fixed resource reservation mode and realizes the precise adaptation of channel resources and safety requirements; the semantic-level criticality analysis deeply parses the underlying logical associations of instructions and constructs a dynamic priority mapping; the fragmentation reorganization and redundant transmission technology significantly reduces the impact of upgrade interruptions on the system and ensures the reliable delivery of critical instructions; the compensatory transmission mechanism balances the timely recovery of safety instructions and the transmission efficiency of non-critical data through differentiated strategies.

[0070] The present invention enhances the adaptability of the in-vehicle network to complex scenarios, improving the efficiency of OTA upgrades while ensuring real-time control reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] ​In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0072] Figure 1 Schematic diagram of the data transmission method of the vehicle controller in Example 1. DETAILED DESCRIPTION

[0073] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0074] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0075] Secondly, the term "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in various places throughout this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive of other embodiments.

[0076] Example 1, with reference to Figure 1 , this embodiment provides a data transmission method of a vehicle-mounted controller, comprising the following steps:

[0077] Step S1, when an OTA upgrade request is detected, dynamically allocating the bandwidth ratio of the control instruction transmission channel and the upgrade data transmission channel according to the current vehicle operating state;

[0078] The specific steps of dynamically allocating bandwidth ratios in step S1 include:

[0079] Establish a mapping relationship table between vehicle operating status parameters and minimum reserved bandwidth, including vehicle speed, gear position, and autonomous driving mode;

[0080] Correct the calculation weight of the minimum reserved bandwidth according to the steering wheel angle change rate obtained in real time;

[0081] When it is detected that the brake pedal opening exceeds the threshold, the control command channel bandwidth ratio is forced to increase to more than 80%;

[0082] Step S2, performing semantic-level criticality analysis on the vehicle control instructions and generating an instruction transmission priority mapping table;

[0083] The semantic level criticality analysis method of step S2 includes:

[0084] Parse the DBC definition file of the control instruction and extract the signal source component, data refresh cycle and dependency parameters;

[0085] Construct an instruction impact assessment model whose input includes the actuator response delay associated with the instruction and the system safety level;

[0086] Generate a dynamically updated priority mapping table containing the instruction ID, minimum transmission delay requirement, and the upper limit of the allowed number of retransmissions;

[0087] In step S2, the instruction impact assessment model is constructed as follows:

[0088] The system integrates three indicators: actuator response latency, system safety level, and signal dependency, to quantitatively assess the criticality of each control instruction during the OTA upgrade process. Once completed, the system generates a discrete priority and related transmission parameters based on the score.

[0089] In step S2, the steps of performing semantic-level criticality analysis on the vehicle control instructions and generating an instruction transmission priority mapping table include:

[0090] Combine the indicators in a weighted manner to form an impact score:

[0091] Among them, I i represents the impact score of instruction index i, a represents the executor delay impact weight, Δ r ef represents the reference maximum response delay, Δ i represents the actual response delay of the actuator corresponding to instruction i, b represents the safety level impact weight, S i Indicates the system security level score of instruction i, S max represents the maximum score of the system security level, c represents the dependency impact weight, R i Indicates the number of signal sources that instruction i depends on, R max Indicates the maximum number of dependent signals among all instructions, i indicates the corresponding instruction i;

[0092] Discretize the continuous value of influence into priority level, the formula is:

[0093]

[0094] Among them, P i Indicates the priority level of instruction i, M indicates the total number of preset priority levels,

[0095] represents the maximum impact score obtained among all instruction index j;

[0096] The minimum transmission delay requirement is calculated based on the impact score. The calculation formula is:

[0097] δ i =δ0 / I i , where δ i represents the minimum transmission delay requirement of instruction i, δ0 represents the benchmark transmission delay threshold;

[0098] Calculate the maximum retransmission limit for each instruction:

[0099]

[0100] in, Indicates the maximum number of retransmissions allowed for instruction i, τ slot Indicates the length of the communication time slot;

[0101] After the calculation is completed, the field instruction IDi, the minimum transmission delay δ i , priority P i Maximum number of retransmissions Summarize by instruction index to form a dynamically updated instruction transmission priority mapping table;

[0102] Step S3: When the upgrade data packet and the control instruction compete for a channel, a transmission mode switch is triggered based on the priority mapping table;

[0103] Step S4, using the data packet fragmentation and reassembly mechanism to process the interrupted upgrade data, retaining the fragment identification and verification information of the interruption point;

[0104] The data packet fragmentation and reassembly mechanism in step S4 includes:

[0105] Divide the upgrade data packet into fixed-size transmission units, and append a header containing the fragment sequence number and context association code to each unit;

[0106] When switching channels, the sequence number of the last successfully transmitted fragment is recorded, and a breakpoint information frame containing the identifier of the untransmitted fragment is generated;

[0107] Based on the verification result fed back by the receiving end, the damaged fragment and its two adjacent fragments are selectively retransmitted;

[0108] Step S5: continuously monitor the waiting time of the control instruction queue during the upgrade transmission process and dynamically adjust the bandwidth allocation ratio;

[0109] Step S6: When a safety-related instruction is identified, a preset redundant transmission path is activated for parallel data delivery;

[0110] The redundant transmission path activation conditions of step S6 include:

[0111] When the control instruction has been waiting in the queue for longer than its associated safety response threshold;

[0112] When the current channel bit error rate is detected to exceed the set threshold for three consecutive sampling cycles;

[0113] The redundant transmission path uses a combination of heterogeneous channels, including parallel transmission channels of the CAN bus and the in-vehicle Ethernet;

[0114] The data transfer method also includes a compensation transfer mechanism:

[0115] After each channel switch, count the number and type of data packets lost due to the switch;

[0116] The compensation transmission period is selected based on the network load status. The period is determined based on historical traffic fluctuation patterns and real-time remaining bandwidth.

[0117] A preemptive retransmission strategy is used for compensatory transmission of safety-related instructions, and an idle period retransmission strategy is used for non-safety instructions;

[0118] In the compensation transmission mechanism, to ensure that safety-related commands can be promptly resumed during OTA upgrades and that non-safety commands are retransmitted during idle periods, this step uses both preemptive and idle period compensation strategies, while also maintaining cache management and preemption signal generation logic.

[0119] In the compensation transmission mechanism, the preemption trigger signal for safety-related instructions is defined:

[0120] Calculate the urgency index for the security instruction with instruction index i:

[0121] G i =H(T w,i -T th,i )+H(E err -E th ),

[0122] Among them, G i Represents the preemption trigger signal (binary), H(x) is a unit step function, H(0) = 0, takes 1 when x>0, otherwise takes 0, the dimension of x is the same as T w,i and E err Consistent, T w,i Indicates the cumulative waiting time of instruction i in the queue, T th,i represents the safety response threshold of instruction i, E err Indicates the current channel bit error rate, E th Indicates the bit error rate threshold,

[0123] When Gi When ≥1, the corresponding instruction triggers preemptive retransmission;

[0124] All fragments to be retransmitted for this command are immediately pushed into the preemptive cache pool. Cache management uses a double-key sorting method based on command priority and fragment sequence number:

[0125] Press (P i ,-k) in descending order,

[0126] in, is the cache pool set, D i,k Indicates the kth slice data of instruction i, P i is the priority of instruction i in the mapping table. The smaller the sequence number k, the earlier the fragment is generated. Therefore, -k is used to implement first-come-first-served.

[0127] When the buffer overflows , remove the item with the lowest priority and the largest fragment number in the current collection:

[0128]

[0129] To ensure that high-priority shards are retained;

[0130] For non-safety instructions, the idle period retransmission strategy is adopted and the channel utilization is defined as follows:

[0131] U(t)=D active (t) / D cap ,

[0132] Among them, U(t) represents the channel utilization at time t, D active (t) is the current active traffic rate, D cap is the maximum carrying rate of the channel, when U(t) idle When the idle threshold is reached, the system takes out the non-safe fragments from the idle buffer pool and sends them in the order of generation without preemption. Otherwise, it waits for the next idle period. idle Indicates the channel utilization threshold that triggers idle supplementary transmission;

[0133] Specifically, the compensation strategy here separates the scheduling of safety-related instructions from non-safety instructions, and uses preemptive retransmission to ensure that safety instructions can be quickly restored in abnormal situations, reducing the risk of response delays. At the same time, it uses idle periods to retransmit non-safety instructions to avoid competing for bandwidth with critical data. The preemption signal is triggered based on the instruction waiting time and bit error rate. The logic is simple and easy to implement in hardware. The cache double-key sorting and overflow elimination mechanism ensure that high-priority data is not discarded. The channel utilization threshold dynamically determines the channel idle period, improving bandwidth utilization efficiency and enhancing the system robustness and security during the OTA upgrade process.

[0134] ​The data transmission method includes initialization configuration steps before implementation, specifically:

[0135] Preload the communication topology diagram of each vehicle controller, which includes the physical connection type and data flow between each node;

[0136] Set the sensitivity coefficient for dynamic bandwidth adjustment. The coefficient is configured differently based on the computing resource margin of the vehicle platform.

[0137] Establish an instruction priority conflict arbitration rule base, which contains the judgment logic of priority coverage relationships in different scenarios;

[0138] The way to set the sensitivity coefficient of dynamic bandwidth adjustment is:

[0139] The sensitivity coefficient κ is introduced to map the relationship between resource margin and adjustment amplitude. The sensitivity coefficient formula is defined as:

[0140]

[0141] Where κ represents the sensitivity coefficient of dynamic bandwidth adjustment, min Represents the minimum sensitivity coefficient, with a value range of [0.1, 0.3], κ max Indicates the maximum sensitivity coefficient, the value range is [0.7, 1.0], C avail Indicates the remaining computing resources of the current vehicle platform, C tot represents the total computing resources of the vehicle platform, p represents the sensitivity curve index, C avail and C tot Both are expressed as the percentage of processor remaining / total computing power, used to control the concavity of the mapping function, with a value range of [1,3];

[0142] To supplement the quantitative standards, three additional resource margin intervals and corresponding coefficients are defined:

[0143] 1. When When κ=0.2,

[0144] 2. When When κ=0.5,

[0145] 3. When When κ=0.8;

[0146] In actual deployment, κ is fine-tuned based on vehicle performance test results. min κ max p-value;

[0147] Specifically, by mapping the platform resource margin to the bandwidth adjustment sensitivity, adaptive on-demand allocation capability is achieved. The sensitivity coefficient model uses a smaller κ in the low resource margin stage to limit the bandwidth adjustment range and prevent system overload. A larger κ is used in the high resource margin period to make bandwidth allocation more flexible and improve OTA upgrade efficiency. The introduction of the exponent p increases the plasticity of the mapping function, and the convexity can be determined based on actual vehicle tests, thereby optimizing the response curve. In addition, the three-level quantization standard provides a simple configuration solution for engineering implementation, facilitating rapid deployment and debugging.

[0148] It should be noted that the above embodiments are only used to illustrate the technical solutions 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 preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A data transmission method for a vehicle-mounted controller, characterized in that: include, Step S1, when an OTA upgrade request is detected, dynamically allocating the bandwidth ratio of the control instruction transmission channel and the upgrade data transmission channel according to the current vehicle operating state; Step S2, performing semantic-level criticality analysis on the vehicle control instructions and generating an instruction transmission priority mapping table; Step S3, when the upgrade data packet and the control instruction compete for a channel, triggering a transmission mode switch based on the priority mapping table; Step S4, using the data packet fragmentation and reassembly mechanism to process the interrupted upgrade data, retaining the fragment identification and verification information of the interruption point; Step S5, continuously monitoring the waiting time of the control instruction queue during the upgrade transmission process, and dynamically adjusting the bandwidth allocation ratio; Step S6: When a safety-related instruction is identified, a preset redundant transmission path is activated for parallel data delivery.

2. The data transmission method of a vehicle-mounted controller according to claim 1, characterized in that: The specific steps of dynamically allocating bandwidth ratios in step S1 include: Establishing a mapping relationship table between vehicle operating state parameters and minimum reserved bandwidth, wherein the parameters include vehicle speed, gear position, and autonomous driving mode; Correcting the calculation weight of the minimum reserved bandwidth according to the steering wheel angle change rate obtained in real time; When it is detected that the brake pedal opening exceeds the threshold, the control command channel bandwidth ratio is forced to increase to more than 80%.

3. The data transmission method of a vehicle-mounted controller according to claim 1, characterized in that: The semantic level criticality analysis method of step S2 includes: Parse the DBC definition file of the control instruction and extract the signal source component, data refresh cycle and dependency parameters; Constructing an instruction impact assessment model, wherein the model input includes an actuator response delay associated with the instruction and a system safety level; Generate a dynamically updated priority mapping table, which includes the instruction ID, the minimum transmission delay requirement, and the upper limit of the allowed retransmission times.

4. The data transmission method of a vehicle-mounted controller according to claim 3, characterized in that: In step S2, the instruction impact assessment model is constructed as follows: The three indicators of actuator response delay, system safety level and signal dependency are integrated to quantitatively evaluate the criticality of each control instruction in the OTA upgrade process. After completion, the discrete priority and related transmission parameters are generated based on the score.

5. The data transmission method of a vehicle-mounted controller according to claim 4, characterized in that: In step S2, the step of performing semantic-level criticality analysis on the vehicle control instructions and generating an instruction transmission priority mapping table includes: Combine the indicators in a weighted manner to form an impact score: Among them, I i represents the impact score of instruction index i, a represents the executor delay impact weight, Δ ref Indicates the reference maximum response delay, Δ i represents the actual response delay of the actuator corresponding to instruction i, b represents the safety level impact weight, S i Indicates the system security level score of instruction i, S max represents the maximum score of the system security level, c represents the dependency impact weight, R i Indicates the number of signal sources that instruction i depends on, R max Indicates the maximum number of dependent signals among all instructions, i indicates the corresponding instruction i; Discretize the continuous value of influence into priority level, the formula is: Among them, P i Indicates the priority level of instruction i, M indicates the total number of preset priority levels, represents the maximum impact score obtained among all instruction index j; The minimum transmission delay requirement is calculated based on the impact score. The calculation formula is: δ i =δ0 / I i , where δ i represents the minimum transmission delay requirement of instruction i, δ0 represents the benchmark transmission delay threshold; Calculate the maximum retransmission limit for each instruction: in, Indicates the maximum number of retransmissions allowed for instruction i, τ slot Indicates the length of the communication time slot; After the calculation is completed, the field instruction IDi, the minimum transmission delay δ i , priority P i Maximum number of retransmissions Summarize by instruction index to form a dynamically updated instruction transmission priority mapping table.

6. The data transmission method of a vehicle-mounted controller according to claim 1, characterized in that: The data packet fragmentation and reassembly mechanism in step S4 includes: Divide the upgrade data packet into fixed-size transmission units, and append a header containing the fragment sequence number and context association code to each unit; When switching channels, the sequence number of the last successfully transmitted fragment is recorded, and a breakpoint information frame containing the identifier of the untransmitted fragment is generated; Based on the verification result fed back by the receiving end, the damaged fragment and its two adjacent fragments are selectively retransmitted.

7. The data transmission method of a vehicle-mounted controller according to claim 1, characterized in that: The redundant transmission path activation conditions of step S6 include: When the control instruction has been waiting in the queue for longer than its associated safety response threshold; When the current channel bit error rate is detected to exceed the set threshold for three consecutive sampling cycles; The redundant transmission path adopts a combination of heterogeneous channels, including parallel transmission channels of the CAN bus and the vehicle Ethernet.

8. The data transmission method of a vehicle-mounted controller according to claim 1, characterized in that: The method also includes a compensation transfer mechanism: After each channel switch, count the number and type of data packets lost due to the switch; Selecting a compensation transmission period based on the network load status, wherein the period is determined based on historical traffic fluctuation patterns and real-time remaining bandwidth; A preemptive retransmission strategy is used for the compensatory transmission of safety-related instructions, while an idle period compensatory transmission strategy is used for non-safety instructions.

9. The data transmission method of a vehicle-mounted controller according to claim 8, characterized in that: In the compensation transmission mechanism: two compensation strategies, preemptive and idle period, are adopted, while maintaining the cache management and preemption signal generation logic; In the compensation transmission mechanism, a preemption trigger signal for safety-related instructions is defined: Calculate the urgency index for the security instruction with instruction index i: G i =H(T w,i -T th,i )+H(E err -E th ), Among them, G i Represents the preemption trigger signal, H(x) is a unit step function, H(0)=0, takes 1 when x>0, otherwise takes 0, the dimension of x is the same as T w,i and e err Consistent, T w,i Indicates the cumulative waiting time of instruction i in the queue, T th,i represents the safety response threshold of instruction i, E err Indicates the current channel bit error rate, E th Indicates the bit error rate threshold, When G i When ≥1, the corresponding instruction triggers preemptive retransmission; All fragments to be retransmitted for this command are immediately pushed into the preemptive cache pool. Cache management uses a double-key sorting method based on command priority and fragment sequence number: Press (P i ,-k) in descending order, in, is the cache pool set, D i,k Indicates the kth slice data of instruction i, P i is the priority of instruction i in the mapping table. The smaller the sequence number k, the earlier the fragment is generated. Therefore, -k is used to implement first-come-first-served. When the buffer overflows , remove the item with the lowest priority and the largest fragment number in the current collection: For non-safety instructions, the idle period retransmission strategy is adopted and the channel utilization is defined as follows: U(t)=D active (t) / D cap , Among them, U(t) represents the channel utilization at time t, D active (t) is the current active traffic rate, D cap is the maximum carrying rate of the channel, when U(t) idle When the idle threshold is reached, the system takes out the non-safe fragments from the idle buffer pool and sends them in the order of generation. Otherwise, it waits for the next idle period. idle Indicates the channel utilization threshold that triggers idle retransmission.​ 10. The data transmission method of a vehicle-mounted controller according to claim 1, characterized in that: The method includes the following initialization configuration steps before implementation: Preload the communication topology diagram of each vehicle controller, which includes the physical connection type and data flow between each node; Set the sensitivity coefficient of dynamic bandwidth adjustment, which is configured differently according to the computing resource margin of the vehicle platform; An instruction priority conflict arbitration rule base is established, wherein the rule base includes decision logic for priority coverage relationships in different scenarios.

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