Resource scheduling method for AUTBUS multi-subnet network

Abstract

The invention relates to a resource scheduling method oriented to an AUTBUS multi-subnet network, and belongs to the technical field of industrial internet. The method comprises the following steps: acquiring a traffic set and network type parameters of each subnet, screening out cross-subnet traffic, generating a to-be-scheduled sequence Q, calculating an ideal basic period and a scheduling period according to a traffic period, determining an emission mode, the basic period and the scheduling period, and calculating the number of time slots required by each traffic; then, the types of the flow source subnets are judged in sequence, deterministic source subnet processing and non-deterministic source subnet processing are carried out respectively, the deterministic source subnets distribute free time slots based on conflict detection, and the non-deterministic source subnets are distributed through a skyline heuristic algorithm; and after the sequence to be scheduled is scheduled, the static time slot resources of the backbone network are allocated, and a data transmission stage is entered. According to the invention, time delay and jitter of cross-subnet flow can be reduced, stable transmission of key cross-subnet service data is ensured, and real-time performance and reliability of cross-subnet communication of an industrial field network are ensured.

Description

Technical Field

[0001] This invention belongs to the field of industrial internet technology and relates to a resource scheduling method for AUTBUS multi-subnet networks. Background Technology

[0002] With the development of the Industrial Internet, industrial sites pose a dual challenge to the performance of industrial field networks—requiring both high bandwidth to support large data transmissions and meeting the stringent real-time and deterministic requirements of industrial control scenarios. Traditional industrial fieldbus technologies such as PROFIBUS, Modbus, and CAN bus are gradually revealing their technical bottlenecks. Their inherent limitations, such as limited transmission distance, insufficient bandwidth, weak anti-interference capabilities, and inadequate real-time performance, make them unsuitable for the long-distance transmission, high bandwidth, and high real-time requirements of the Industrial Internet. As a representative of next-generation industrial communication technology, AUTBUS achieves a multi-dimensional performance leap with its groundbreaking technical architecture, meeting the bandwidth and real-time demands of intelligent manufacturing.

[0003] AUTBUS employs frequency division multiplexing (FDM) technology, achieving an effective transmission bandwidth of up to 100Mbps. Its innovative time-slot scheduling mechanism compresses the minimum cycle time to 8μs, ensuring deterministic transmission of control commands. In terms of physical layer design, anti-interference coding and equalization optimization enable the system to maintain an ultra-low bit error rate on the order of 10^-12 even at a transmission distance of 500 meters. In industrial settings, AUTBUS achieves compatible access to traditional field devices through conversion modules, eliminating the need for complete replacement of existing equipment and significantly reducing upgrade costs. This compatibility and conversion capability make AUTBUS not only a technological breakthrough but also an economical choice for upgrading industrial fieldbuses, providing a practical solution for the development of the Industrial Internet. The AUTBUS / ETH module within the conversion module enables seamless connection between field devices and Ethernet, directly connecting industrial equipment to the Internet, achieving data uploading to the cloud and broader interconnectivity. This connectivity not only enhances the data integration and remote management capabilities of industrial equipment but also provides a technological foundation for deep applications of the Industrial Internet, such as remote monitoring, predictive maintenance, intelligent analysis, and cross-regional collaborative work. These technical characteristics have made AUTBUS a research hotspot and a preferred engineering practice solution in the field of industrial communication.

[0004] Current research on AUTBUS network scheduling algorithms still faces three critical technical bottlenecks that urgently need to be overcome. First, existing research is largely limited to resource scheduling optimization within a single network domain, lacking a cross-domain collaborative scheduling architecture that meets the interconnection needs of heterogeneous networks. Second, in hybrid networking scenarios consisting of an AUTBUS backbone and multiple types of subnets, although data plane interconnection is achieved through protocol conversion modules, the Quality of Service (QoS) guarantee mechanism for various service flows in the overall AUTBUS multi-subnet network is still incomplete. Finally, as a transmission hub for multi-source heterogeneous traffic, the AUTBUS backbone needs to simultaneously carry mixed services with different latency requirements; the extensive resource scheduling mode of allocating fixed AUTBUS bandwidth cannot ensure the real-time performance and reliability of industrial field networks. Summary of the Invention

[0005] In view of this, the purpose of this invention is to provide a resource scheduling method for AUTBUS multi-subnet networks, which solves the resource scheduling problem of cross-subnet data flow in the data layer of the AUTBUS multi-subnet network architecture, so as to reduce the latency and jitter of cross-subnet traffic, ensure the stable transmission of critical cross-subnet service data, and guarantee the real-time performance and reliability of cross-subnet communication in industrial field networks.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A resource scheduling method for AUTBUS multi-subnet networks, the method comprising:

[0008] Based on the AUTBUS multi-subnet network topology built by the user, obtain the traffic set F and network type parameters of each subnet in the AUTBUS multi-subnet network;

[0009] Data streams f are filtered from each subnet traffic set F based on cross-subnet traffic characteristics and periods. i,j And generate the scheduler sequence Q through priority mapping rules and sorting rules;

[0010] Based on the transmission period T of each traffic in the sequence to be scheduled Q i,j Calculate the ideal fundamental period BC and the ideal scheduling period SC to determine the AUTBUS transmission mode m and the fundamental period BC. T and scheduling period SC T ;

[0011] Based on the frame length LEN of each traffic in the sequence Q to be scheduled i,j Calculate the number n of time slot symbols required. i,j ;

[0012] The source subnet type of each traffic flow is determined sequentially according to the order in the scheduling sequence Q. Based on the determination result, the flow enters the deterministic source subnet processing process and the non-deterministic source subnet processing process of AUTBUS backbone network resource scheduling respectively.

[0013] In the process of deterministic source subnet processing, the time it takes for the traffic to travel from the source node to the source subnet gateway is first calculated by calling the scheduling algorithm of the corresponding subnet. Then, based on the number of symbols n required for this traffic... i,j and time Perform free symbol allocation based on conflict detection;

[0014] During the nondeterministic source subnet processing, the skyline heuristic algorithm is used to schedule based on the remaining time slot resources of the AUTBUS backbone network and the number of symbols required by the traffic, and to determine the allocation of conflict-free idle symbols.

[0015] After scheduling each traffic item in the scheduled sequence Q, the AUTBUS multi-subnet network completes the allocation of static time slot resources in the backbone network and enters the data transmission phase.

[0016] Furthermore, the traffic set F of each subnet in an AUTBUS multi-subnet network is represented as: F = {F1, F2, F3, ..., F...} i}, F i Let F be the set of real-time periodic data traffic for subnet i, where F i ={f i,1 ,f i,2 ,...f i,j}, f i,j Let j be the j-th traffic in subnet i; each subnet has at least one traffic instance transmitted through the AUTBUS backbone.

[0017] The network type parameter includes deterministic and nondeterministic networks, and each traffic item corresponds to one of these network types.

[0018] Furthermore, the CNF flag for cross-subnet traffic is extracted from the traffic set F. i,j =1 and period T i,j Flow f ≠ null i,j This is used to generate a scheduler sequence Q = {f} through priority mapping rules and sorting rules. i,j |CNF i,j =1,T i,j ≠null}, where the flow rate f i,j The method of obtaining it is:

[0019] Encapsulate cross-subnet data transmissions into standardized AUTBUS data streams:

[0020] f i,j (Src i,j Des i,j ,LEN i,j ,T i,j ,DR i,j ,TYPE i,j CNF i,j )

[0021] Among them, Src i,j It is a flow f i,j The source node; Des i,j It is a flow f i,j Destination node; LEN i,j It is a flow f i,j The frame length, in bytes; DR i,j It is a flow f i,j Maximum end-to-end allowable latency, in milliseconds. This bit is null for non-real-time periodic or non-real-time non-periodic data traffic; T i,j It is a flow f i,j The transmission period, in milliseconds. This bit is null for real-time non-periodic or non-real-time non-periodic data traffic; TYPE i,j It is a flow f i,j The type, in addition to indicating f i,j Priority, TYPE i,j The smaller the value, the higher the traffic priority (CNF). i,j For cross-subnet traffic flags, if f i,j This bit is 1 for cross-subnet traffic and 0 otherwise.

[0022] Furthermore, in the process of generating the sequence Q to be scheduled, the priority mapping rule refers to dividing the priority of non-real-time periodic data and non-real-time aperiodic data into the lowest priority of 255, while real-time periodic data and real-time aperiodic data are prioritized according to latency requirements, as shown in the following formula:

[0023]

[0024] In the formula, TYPE i,j f i,j Priority, Pri max Pri represents the maximum priority in the network. min This represents the minimum priority value in the network.

[0025] The priority of non-real-time periodic data and non-real-time non-periodic data is divided into 255, DR i,j f i,j The latency requirement, This represents the maximum delay requirement for each traffic stream in Q. This represents the minimum latency requirement for each traffic stream in Q;

[0026] The sorting rules first rank all traffic according to priority. Secondly, for traffic with the same priority, shorter periods rank higher; for traffic with the same priority and period, shorter lengths rank higher; for traffic with the same priority, period, and length, smaller sequence numbers (i) rank higher; for traffic with the same priority, period, length, and sequence number (i), smaller sequence numbers (j) rank higher. A scheduling sequence Q = {f} is generated. i,j |CNF i,j =1,T i,j ≠null}.

[0027] Furthermore, based on the sending period T of each traffic stream... i,j The ideal fundamental period BC and the ideal scheduling period SC are calculated as follows:

[0028] BC = GCD(T) 1，1 ,T 1，2 ,...,T i,j )

[0029] SC = LCM(T) 1，1 ,T 1，2 ,...,T i,j )

[0030] Among them, T i,j f i,j The transmission period, GCD(T) 1,1 ,T 1,2 ...T i,j ) indicates the calculation of T 1,1 ,T 1,2 ...T i,j The greatest common divisor of LCM(T) 1,1 ,T 1,2 ...T i,j ) indicates the calculation of T 1,1 ,T 1,2 ...T i,j The least common multiple; SC consists of several BCs, and all traffic in Q is transmitted at least once in an SC, with the number of transmissions and the transmission time being the same in each SC;

[0031] The transmission mode m determines the duration of one AUTBUS frame, BC T This refers to the basic period of actual transmission, SC T This refers to the actual transmission scheduling period, where q BCs constitute an AUTBUS frame, i.e., BC T ;p BC T This constitutes a scheduling cycle, i.e., SC T ;have:

[0032]

[0033] In the formula, p represents the number of AUTUS frames in a superframe, q represents the ratio of the duration of an AUTUS frame to BC, with an initial value of 1, and FM is the maximum number of frames contained in an AUTUS superframe, with a value of 8; if the calculated p > FM, then q is increased by 1, and p is calculated again, until p ≤ FM.

[0034] The transmission mode m is based on BC T It is confirmed that the value of m corresponds to the duration of the AUTBUUS frame.

[0035] Furthermore, each traffic f i,j The number of time slot symbols occupied by the transmission window, n i,j The calculation method is as follows:

[0036]

[0037] In the formula, n i,j f i,j The number of symbols occupied by the transmission window, LEN i,j f i,j The frame length is k, where k is the number of bytes carried by a symbol. If the k is not divisible by k, it is rounded up. Each node resource is allocated a time slot as a pilot signal.

[0038] Furthermore, during the deterministic source subnet processing, the traffic set F of subnet i is... i The set of traffic F destined for subnet i. i′ As input, the scheduling algorithm of the corresponding subnet is invoked to calculate the transmission path, resource allocation scheme, and the initial time τ of each traffic flow. i,j Further f i,j The theoretical delay from the source node sending the message to the source subnet gateway preparing to send it. The time it takes for each traffic item in the deterministic source subnet to reach the source subnet gateway is calculated.

[0039] During the cyclic collision detection process, according to and n i,j Detect f i,j If a conflict occurs with the symbol resources required by other traffic, the system checks for conflicts. If a conflict occurs, the system shifts to the next available symbol, checks for conflicts again, and if a conflict still occurs, shifts to the next available symbol. This process is repeated until f is detected. i,j This free symbol does not conflict with the symbol resources required by other traffic, and will contain the free symbol and the (n) symbol following it. i,j -1) symbols are assigned to fi,j ;

[0040] If not enough time slots are allocated to f during the entire scheduling cycle i,j Then determine f i,j Scheduling failed.

[0041] Furthermore, during the processing of the nondeterministic source subnet, scheduling is performed based on the remaining time slot resources of the AUTBUS backbone and the number of symbols required by the traffic to determine conflict-free idle symbols. If not enough time slot resources are found to allocate to f throughout the entire scheduling cycle... i,j Then f i,j Scheduling failed; the process of the skyline heuristic algorithm is as follows:

[0042] First, read the traffic f. i,j The resource requirements are determined, and then a rectangular space with length l and width s is initialized. The length l represents the number of symbols that the user can use per frame; the width s = p means that p frames form a scheduling cycle.

[0043] Then, the resources occupied by the real-time periodic data traffic are removed to obtain the remaining resource set;

[0044] Traverse the set of remaining resources. If no remaining resource that meets the resource requirements is found, the scheduling fails. If a remaining resource that meets the resource requirements is found, allocate the resource to the traffic, split the remaining part into two parts, add them to the set of remaining resources respectively, and finally delete the resource from the set of remaining resources and output the scheduling result.

[0045] Furthermore, after the traffic resource scheduling of deterministic and non-deterministic source subnets is completed, if the destination subnet is a deterministic destination subnet, the scheduling calculation module calls the scheduling algorithm of the corresponding subnet to schedule the deterministic destination subnet; if the destination subnet is a non-deterministic subnet, it is not scheduled.

[0046] Furthermore, during the data transmission phase, the subnet transmits additional real-time aperiodic data and non-real-time aperiodic data.

[0047] The subnet's gateway sends a resource request to the AUTBUUS Management Node (MN). The MN forwards the required resource information to the collaborative scheduling system and calls the Skyline Heuristic Algorithm again to schedule the remaining symbol resources of the AUTBUUS backbone. If the remaining resources do not meet the requirements, they will not be allocated.

[0048] After completing the transmission of real-time aperiodic data and non-real-time aperiodic data in the AUTBUS multi-subnet network, resources are released through two methods: MN active reclamation or gateway request for release.

[0049] The beneficial effects of this invention are as follows:

[0050] In terms of resource utilization, this invention determines the ideal basic cycle and scheduling cycle by accurately calculating the transmission cycle of each traffic stream, thus rationally planning the usage rhythm of network resources and avoiding resource idleness and waste. Simultaneously, it accurately calculates the required number of time slot symbols based on the traffic frame length, making time slot allocation more precise, greatly improving the utilization rate of backbone network time slot resources, ensuring the network can carry more data traffic, and enhancing overall network performance.

[0051] For handling different types of traffic, this invention calls the corresponding subnet scheduling algorithm and combines it with a conflict detection mechanism for deterministic source subnets, effectively ensuring the stable transmission of critical traffic and reducing transmission latency and conflict probability; for non-deterministic source subnets, it adopts the skyline heuristic algorithm, which can flexibly cope with complex and ever-changing network conditions, quickly find conflict-free idle symbols for allocation, and improve scheduling efficiency and success rate.

[0052] In terms of priority management, this invention ensures that high-priority traffic is scheduled first through reasonable priority mapping rules and sorting rules, which meets the business needs with high real-time requirements and guarantees the quality and reliability of network services.

[0053] Furthermore, this invention also considers the additional transmission requirements of both real-time and non-real-time aperiodic data. By requesting resources through the gateway and re-invoking the Skyline heuristic algorithm for scheduling, dynamic allocation and flexible adjustment of resources are achieved. Simultaneously, two resource release methods—active reclamation or request release—are provided, further optimizing resource management and enabling the network to operate continuously and efficiently, providing a strong guarantee for the stable, reliable, and efficient communication of the AUTBUS multi-subnet network.

[0054] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0055] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein:

[0056] Figure 1 This is a diagram of the AUTBUS multi-subnet network scheduling architecture according to an embodiment of the present invention;

[0057] Figure 2This is a flowchart illustrating the resource scheduling method for AUTBUS multi-subnet networks according to an embodiment of the present invention.

[0058] Figure 3 This is a schematic diagram of time slot resource conflict under an embodiment of the present invention;

[0059] Figure 4 This is a schematic diagram of time slot offset under an embodiment of the present invention;

[0060] Figure 5 This is a flowchart of the skyline heuristic algorithm according to an embodiment of the present invention. Detailed Implementation

[0061] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0062] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0063] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0064] Please see Figures 1-5 This is a resource scheduling method for AUTBUS multi-subnet networks.

[0065] This embodiment first presents a network topology for an AUTBUS multi-subnet network. For example... Figure 1As shown, an AUTBUS multi-subnet network refers to an AUTBUS network that supports three or more industrial field networks to access and carry their data transmission through corresponding gateways. The backbone of an AUTBUS multi-subnet network is AUTBUS, and the subnets are industrial field networks of various protocol types that can access AUTBUS through gateways.

[0066] The user plane of the AUTBUS multi-subnet network scheduling architecture is the user plane APP. The user plane APP provides an interactive interface between users and the collaborative scheduling system. Users can build virtual network topologies and import AUTBUS multi-subnet network traffic sets and network type parameters of each subnet through the user plane APP.

[0067] The control plane of the AUTBUS multi-subnet network scheduling architecture is the collaborative scheduling system. The AUTBUS multi-subnet network resource scheduling algorithm proposed in this invention runs on the scheduling calculation module of the collaborative scheduling system. This module also integrates scheduling algorithms for other industrial networks such as TSN. The collaborative scheduling system receives the AUTBUS multi-subnet network data traffic set and network type parameters of each subnet from the user input through the user plane APP. It obtains the virtual network topology built by the user through the network awareness module. After the scheduling calculation module completes the scheduling of AUTBUS multi-subnet network resources, it distributes the configuration to each subnet through the configuration interface.

[0068] The data plane of the AUTBUS multi-subnet network scheduling architecture is an AUTBUS multi-subnet network, including an AUTBUS backbone network and several subnets. Within the AUTBUS backbone network, AUTBUS defines AUTBUS Management Nodes (MNs) and AUTBUS Terminal Nodes (TNs) based on the logical roles of AUTBUS network nodes. In this invention, the MN is responsible for receiving the resource scheduling results of the AUTBUS backbone network from the control plane's scheduling calculation module and issuing resource allocation instructions to each terminal node. An AUTBUS network has one and only one management node; TNs... i This refers to the composite unit of subnet i and its corresponding gateway. Currently, AUTBUS supports Ethernet, TSN, CAN bus, and RS485 bus access to the AUTBUS backbone network through corresponding gateways.

[0069] At the same time, based on the above topology, a corresponding traffic model and related constraints or conventions are established.

[0070] In the traffic model of this embodiment, the gateway encapsulates cross-subnet transmission data of the corresponding subnet into a standardized AUTBUS data stream f. i,j (Src i,j Des i,j ,LENi,j ,T i,j ,DR i,j ,TYPE i,j CNF i,j ), f i,j The parameter i in f represents i,j From subnet i, parameter j represents f i,j Src represents the j-th traffic in subnet i; i,j It is a flow f i,j The source node; Des i,j It is a flow f i,j Destination node; LEN i,j It is a flow f i,j The frame length, in bytes; DR i,j It is a flow f i,j Maximum end-to-end allowable latency, in milliseconds. This bit is null for non-real-time periodic or non-real-time non-periodic data traffic; T i,j It is a flow f i,j The transmission period, in milliseconds. This bit is null for real-time non-periodic or non-real-time non-periodic data traffic; TYPE i,j It is a flow f i,j The type, in addition to indicating f i,j Priority, TYPE i,j The smaller the value, the higher the traffic priority (CNF). i,j For cross-subnet traffic flags, if f i,j This bit is 1 for cross-subnet traffic and 0 otherwise.

[0071] The constraints or conventions established in this embodiment include:

[0072] (1) In an AUTBUS multi-subnet network, the length, transmission period and deadline of all traffic are known. Data stream transmission must be completed within the deadline and the worst response time must be less than the deadline.

[0073] (2) In an AUTBUS multi-subnet network, only data from the same gateway can be encapsulated into a single data stream, and can only be uniquely encapsulated into a single data stream.

[0074] (3) Within one cycle, the same data stream f i,j Different transmission time slot intervals must be greater than the data stream f i,j transmission period T i,j As shown in the following formula, f i,j Start time of the r-th transmission.

[0075]

[0076] (4) Within a single scheduling cycle, each data stream can be transmitted more than its maximum number of times and each transmission cannot exceed the allocated time slot resource size.

[0077] (5) In AUTBUS, pilot information is needed to confirm the start of a resource block, evaluate the channel and restore the signal. Therefore, when the scheduling calculation module allocates resources, it needs to insert pilot information according to different bearer modes based on the symbols required to meet the transmission traffic.

[0078] (6) AUTBUS supports two bearer modes: Bearer Mode A and Bearer Mode B. Bearer Mode A transmits both data and pilot signals in a single symbol, with a pilot signal to data ratio of 1:8. Bearer Mode B transmits pilot signals in the first assigned symbol and data in subsequent symbols. In this invention, Bearer Mode B is used by default.

[0079] (7) The transmission period T for cross-subnet traffic transmitted via AUTBUS is agreed upon. i,j The following constraints need to be satisfied: T i,j It must be a standard periodic set F T = an element in {0.5ms, 1ms, 2ms, 4ms, 8ms, 16ms, 32ms} or a value divisible by it. This standard period set originates from the fact that AUTUS currently only supports integers where m is [0, 3]. The frame durations corresponding to these four transmission modes are 0.5ms, 1ms, 2ms, and 4ms, respectively. AUTUS only supports setting 1, 2, 4, and 8 frames to form a superframe, so the settable standard period is F. T The elements in the [concept / concept]. When the AUTBUS protocol is extended to support more transmission modes or more flexible superframe configurations, the periodic constraints of this invention can also be extended to support a wider range of periodic parameter choices.

[0080] (8) The upper and lower sideband coding method is set to 3 to ensure a higher demodulation threshold signal-to-noise ratio.

[0081] In cross-subnet end-to-end communication scenarios, the subnet where the source node of a data stream is located is called the source subnet. If the source subnet has deterministic network service capabilities, the type of the subnet is called a deterministic source subnet; otherwise, it is called a non-deterministic source subnet. The subnet where the destination node is located is called the destination subnet. If the destination subnet has deterministic network service capabilities, the type of the subnet is called a deterministic destination subnet; otherwise, it is called a non-deterministic destination subnet.

[0082] In this embodiment, the present invention mainly solves the problem of data flow transmission scheduling across subnets in the AUTBUS multi-subnet network architecture, so as to reduce the latency and jitter of cross-subnet traffic and ensure the real-time performance and stability of communication.

[0083] This invention categorizes AUTBUS multi-subnet network traffic into four types: real-time periodic data, real-time aperiodic data, aperiodic periodic data, and aperiodic aperiodic data. When scheduling AUTBUS backbone network resources, fixed AUTBUS resources are allocated for real-time periodic data and aperiodic data, while dynamic access bandwidth requests are used for real-time aperiodic data and aperiodic aperiodic data. Before designing the scheduling method, a traffic model needs to be designed and constraints determined.

[0084] Specifically, in this embodiment, a resource scheduling method for AUTBUS multi-subnet networks according to the present invention includes the following steps:

[0085] Step 1: The user builds an AUTBUS multi-subnet network topology in the user-facing APP, and inputs the traffic set F = {F1, F2, F3, ..., F} for each subnet in the AUTBUS multi-subnet network. i} and network type parameter, where F i ={f i,1 ,f i,2 ,...f i,j};

[0086] Step 2: The scheduling calculation module extracts the cross-subnet traffic flag (CNF) from F. i,j =1 and period T i,j Non-null data stream f i,j Then, it is used to generate a scheduler sequence Q = {f} through priority mapping rules and sorting rules. i,j |CNF i,j =1,T i,j ≠null};

[0087] Step 3: The scheduling calculation module calculates the transmission period T of each traffic stream in Q. i,j Calculate the ideal fundamental period BC and the ideal scheduling period SC to determine the AUTBUS transmission mode m and the fundamental period BC. T and scheduling period SC T ;

[0088] Step 4: The scheduling calculation module calculates the frame length (LEN) of each traffic stream in Q. i,j Calculate the number of time slot symbols n required. i,j ;

[0089] Step 5: The scheduling calculation module retrieves each traffic item from Q in a forward-to-back order. Based on the network type parameter, it determines the source subnet type of the traffic item. If the source subnet is deterministic, it calculates the subnet traffic f by calling the corresponding subnet's scheduling algorithm. i,j The starting moment τi,j and f i,j The theoretical delay from the source node sending the message to the source subnet gateway preparing to send it. Includes the gateway's processing latency δ. The time it takes for each traffic item from the deterministic source subnet to reach the source subnet gateway is calculated. If f i,j Since the source subnet is a nondeterministic source subnet, proceed directly to step six;

[0090] Step Six: If the source subnet is a deterministic source subnet, the scheduling calculation module calculates n based on the result obtained in Step Four. i,j and the result obtained in step five Detect f i,j If a conflict occurs with the symbol resources required by other traffic, the system checks for conflicts. If a conflict occurs, the system shifts to the next available symbol, checks for conflicts again, and if a conflict still occurs, shifts to the next available symbol. This process is repeated until f is detected. i,j This free symbol does not conflict with the symbol resources required by other traffic, and will be used to store this free symbol and the (n) symbol following it. i,j -1) symbols are assigned to f i,j If the scheduling computation module fails to find enough time slot resources to allocate to f throughout the entire scheduling cycle i,j Then determine f i,j Scheduling failed. If f i,j The source subnet is a nondeterministic source subnet. The scheduling calculation module uses the skyline heuristic algorithm to schedule traffic based on the remaining time slot resources of the AUTBUS backbone and the number of symbols required for the traffic. It determines conflict-free idle symbols. If the scheduling calculation module cannot find enough time slot resources to allocate to f during the entire scheduling cycle, i,j Then determine f i,j Scheduling failed;

[0091] Step 7: After the AUTBUS backbone network resource scheduling is completed, the arrival time of each data stream in Q, including traffic from non-deterministic source subnets, at the destination subnet gateway is deterministic. If the destination subnet is deterministic, the scheduling calculation module calls the corresponding subnet's scheduling algorithm to schedule the deterministic destination subnet; if the destination subnet is non-deterministic, it is not scheduled. After scheduling each traffic stream in Q, the static time slot resource allocation of the AUTBUS multi-subnet network backbone is completed, and the data transmission phase begins.

[0092] During the data transmission phase, the AUTBUS multi-subnet network, in addition to transmitting traffic from F, also needs to transmit real-time aperiodic and non-real-time aperiodic data from the subnets. Users cannot know these two types of data in advance; they can only be obtained during the data transmission phase when the subnet's gateway sends a resource request to the MN. The MN then forwards the required resource information to the collaborative scheduling system. The scheduling calculation module again calls the Skyline heuristic algorithm to schedule the remaining symbol resources of the AUTBUS backbone network. If the remaining resources do not meet the demand, they are not allocated. After the AUTBUS multi-subnet network completes the transmission of real-time and non-real-time aperiodic data, resources can be released through either MN proactive reclamation or gateway request for release. The above steps are repeated for subsequent transmission needs.

[0093] In this embodiment, the inputs to the AUTBUS multi-subnet network resource scheduling method are: the AUTBUS multi-subnet network topology, the real-time periodic data traffic set F, and the network type parameters of subnet i.

[0094] The AUTBUS multi-subnet network resource scheduling method outputs: the resource allocation scheme between the subnet and the AUTBUS backbone network within a scheduling cycle.

[0095] The detailed execution flow of the AUTBUS multi-subnet network resource scheduling method is as follows:

[0096] (1) User input

[0097] Users build an AUTBUS multi-subnet network topology in the user-facing app, inputting the traffic set F = {F1, F2, F3, ..., F...} for each subnet in the AUTBUS multi-subnet network. i} and network type parameter. F i The parameter i in F represents F i Let f be the set of real-time periodic data traffic for subnet i, and let parameter j represent f. i,j This represents the j-th traffic instance in subnet i. Each subnet has at least one traffic instance transmitted through the AUTBUS backbone. Users can select between deterministic and non-deterministic networks when inputting the network type parameter.

[0098] (2) Generation of the sequence Q to be scheduled

[0099] The scheduling calculation module extracts the CNF (Cross-Subnet Traffic Flag) bit from F. i,j =1 and period T i,j non-null f i,j Then, it is used to generate a scheduler sequence Q = {f} through priority mapping rules and sorting rules. i,j |CNF i,j =1,T i,j≠null}. It is worth noting that the priority mapping rules and sorting rules are not only used in the generation of Q, but also in the data transmission phase, providing a basis for the scheduling calculation module to determine the order in which resources are allocated to real-time aperiodic data and non-real-time aperiodic data.

[0100] In AUTBUS, a higher priority value indicates a lower priority. Specifically, the priority mapping rule is that the scheduling and calculation module assigns the lowest priority of 255 to non-real-time periodic data and non-real-time aperiodic data. Real-time periodic data and real-time aperiodic data are prioritized based on latency requirements, as shown in the following formula.

[0101]

[0102] In the formula, TYPE i,j f i,j Priority, Pri max Pri represents the maximum priority in the network. min This represents the minimum priority value in the network. The AUTBUS protocol allows users to define a priority range of 0x20 to 0xFF in hexadecimal, or 32 to 255 in decimal. This invention has divided the priority of non-real-time periodic data and non-real-time non-periodic data into 255, therefore, Pri... max =254, Pri min =32. DR i,j f i,j The latency requirement, This represents the maximum delay requirement for each traffic stream in Q. This represents the minimum latency requirement for each traffic flow in Q.

[0103] The sorting rule first sorts all traffic according to priority. For traffic with the same priority, those with shorter periods are sorted first; for those with the same periods, those with shorter lengths are sorted first; for those with the same lengths, those with smaller sequence numbers (i) are sorted first; and for those with the same sequence numbers (i), those with smaller traffic sequence numbers (j) are sorted first. This generates a scheduling sequence Q = {f}. i,j |CNF i,j =1,T i,j ≠null}.

[0104] (3) The scheduling calculation module calculates the ideal fundamental period BC and the ideal scheduling period SC, and determines the AUTBUS transmission mode m and the fundamental period BC. T and scheduling period SC T

[0105] BC refers to the flow f in Q. i,j transmission period T i,j The greatest common divisor (SC) refers to the sum of the values ​​of each flow f in Q. i,j transmission period Ti,j The least common multiple of the values, SC consists of several BCs, and all traffic in Q is transmitted at least once in an SC, with the number of transmissions and the transmission time being the same in each SC. The transmission mode m determines the duration of an AUTBUS frame, BC T This refers to the basic period of actual transmission, SC T This refers to the actual transmission scheduling period.

[0106] The calculation methods for BC and SC are shown in the following formula.

[0107] BC = GCD(T) 1，1 ,T 1，2 ,...,T i,j )

[0108] SC = LCM(T) 1，1 ,T 1，2 ,...,T i,j )

[0109] In the formula, T i,j f i,j The transmission period, GCD(T) 1,1 ,T 1,2 ...T i,j ) indicates the calculation of T 1,1 ,T 1,2 ...T i,j The greatest common divisor of LCM(T) 1,1 ,T 1,2 ...T i,j ) indicates the calculation of T 1,1 ,T 1,2 ...T i,j The least common multiple of .

[0110] SC T =SC scheduling calculation module then determines BC T The calculation shows that q BCs constitute an AUTUS frame, i.e., BC T p BC T This constitutes a scheduling cycle, i.e., SC T .

[0111]

[0112] In the formula, p represents the number of AUTUS frames in a superframe, and q represents the ratio of the duration of an AUTUS frame to the BC (Boundary Frame). q increases from 1. If the calculated p > 8, then q increases by 1, and p is calculated again, until p ≤ 8. 8 is the maximum number of frames contained in an AUTUS superframe as specified in the standard.

[0113] The scheduling calculation module consists of BC TThe transmission mode m is determined, and the correspondence between the value of m and the duration of the AUTBUUS frame is shown in Table 1 below.

[0114] Table 1

[0115]

[0116] The scheduling calculation module calculates real-time periodic data during the scheduling period SC. T Number of internal transmissions K i,j Calculate as shown in the following formula.

[0117]

[0118] (4) The scheduling calculation module calculates each f in Q. i,j The number of time slots n occupied by the transmission window i,j

[0119] f i,j The transmission window refers to the cross-subnet traffic f i,j The symbol resources occupied on the AUTBUS bus are continuous. Each symbol is divided into two half-bands, called the upper sideband and the lower sideband. The different encoding methods of the upper and lower sidebands and the AUTBUS transmission mode m together determine its data carrying capacity, as shown in Table 2 below.

[0120] Table 2

[0121]

[0122] The emission mode m and the top and bottom sideband encoding methods together determine the number of bytes k that a single symbol can carry. For example, when the emission mode m is 0, the top sideband is 2, and the bottom sideband is 3, the number of bytes k that a single symbol can carry is 246 + 406, which means that a single symbol can carry 652 bytes of data.

[0123] f i,j The number of symbols occupied by the transmission window, n i,j The calculation is shown in the following formula.

[0124]

[0125] In the formula, n i,j f i,j The number of symbols occupied by the transmission window, LEN i,j f i,j The frame length is given by k, where k is the number of bytes carried by a symbol. If the value is not divisible by k, it is rounded up. Since each node resource allocation requires an additional time slot as a pilot signal, n... i,j Add 1 to the original amount.

[0126] (5) The scheduling calculation module schedules the source subnet and the destination subnet.

[0127] The scheduling calculation module retrieves each traffic item from Q in a forward-to-back order. Based on the network type parameter, it determines the source subnet type of the traffic item. If the source subnet is deterministic, it takes the traffic set of that subnet and the traffic set of the destination subnet as input, and calls the corresponding subnet's scheduling algorithm to calculate the transmission path, resource allocation scheme, and the initial time τ of each traffic item. i,j Further f i,j The theoretical delay from the source node sending the message to the source subnet gateway preparing to send it. The time it takes for each traffic item in the deterministic source subnet to reach the source subnet gateway is calculated. If f i,j Since the source subnet is nondeterministic, proceed directly to the next step.

[0128] (6) Scheduling and computing module schedules the AUTBUS backbone network

[0129] If the source subnet is a deterministic source subnet, the scheduling calculation module will proceed according to... and n i,j Detect f i,j Does it conflict with the symbol resources required by other traffic, such as... Figure 3 The diagram illustrates a time slot resource conflict, where the symbols used by two traffic flows overlap. If a conflict occurs, the flow is shifted to the next available symbol, as shown below. Figure 4 As shown, the scheduling calculation module checks again for a conflict. If a conflict still occurs, it shifts to the next available symbol, repeating this process until f is detected. i,j This free symbol does not conflict with the symbol resources required by other traffic. The scheduling calculation module uses this free symbol and the (n) symbol following it. i,j -1) symbols are given to f i,j .

[0130] If f i,j The source subnet is a nondeterministic source subnet. This invention uses the skyline heuristic algorithm to schedule traffic based on the remaining time slot resources of the AUTBUS backbone and the number of symbols required for the traffic, thus determining conflict-free idle symbols. If not enough time slot resources are found to allocate to f throughout the entire scheduling cycle... i,j Then f i,j Scheduling failed.

[0131] The flowchart of the skyline heuristic algorithm is as follows: Figure 5As shown. The Skyline heuristic algorithm first reads the resource requirements of the traffic, then initializes a rectangular space with a length l = 57 and a width p. The length is 57 because an AUTBUUS frame contains 64 symbols, but the first 3 and last 4 symbols of each frame are occupied by the system and cannot be used by the user, so the number of symbols that the user can use per frame is 57. The width s = p is because p frames are calculated in step three to form a scheduling cycle. Subsequently, the Skyline heuristic algorithm removes the resources occupied by the real-time periodic data traffic to obtain a set of remaining resources. It iterates through the set of remaining resources. If no remaining resource matching the resource requirements is found, the scheduling fails. If a resource is found, it is allocated to the traffic, and the remaining part is divided into left and right parts and added to the set of remaining resources respectively. Finally, the resource is removed from the set of remaining resources and the scheduling result is output.

[0132] (7) The scheduling and calculation module processes dynamic access requests.

[0133] During the data transmission phase, if the source subnet has a need for real-time aperiodic data transmission and non-real-time aperiodic data transmission, it sends a resource request to the MN through the gateway. The MN then sends the required resource information and the set of remaining time slot resources in the AUTBUS backbone network to the collaborative scheduling system. This invention again invokes the Skyline Heuristic Algorithm to schedule the remaining time slot resources in the AUTBUS backbone network. If the remaining resources do not meet the demand, they are not allocated. After completing the real-time aperiodic data transmission and non-real-time data transmission, resources can be released through either active reclamation or request for release. Subsequent transmission needs will repeat the above dynamic access request process.

[0134] This embodiment also provides a detailed description of the parameters involved in the aforementioned process, as shown in Table 3:

[0135] Table 3

[0136]

[0137]

[0138] Finally, 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 it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A resource scheduling method for AUTBUS multi-subnet networks, characterized in that: The method includes: Based on the AUTBUS multi-subnet network topology built by the user, obtain the traffic set F and network type parameters of each subnet in the AUTBUS multi-subnet network; Data streams f are filtered from each subnet traffic set F based on cross-subnet traffic characteristics and periods. i,j And generate the scheduler sequence Q through priority mapping rules and sorting rules; Based on the transmission period T of each traffic in the sequence to be scheduled Q i,j Calculate the ideal fundamental period BC and the ideal scheduling period SC to determine the AUTBUS transmission mode m and the fundamental period BC. T and scheduling period SC T ; Based on the frame length LEN of each traffic in the sequence Q to be scheduled i,j Calculate the number of symbols n required. i,j ; The source subnet type of each traffic flow is determined sequentially according to the order in the scheduling sequence Q. Based on the determination result, the traffic flows into the deterministic source subnet processing process and the non-deterministic source subnet processing process of AUTBUS backbone network resource scheduling. In the process of deterministic source subnet processing, the time it takes for the traffic to travel from the source node to the source subnet gateway is first calculated by calling the scheduling algorithm of the corresponding subnet. Then, based on the number of symbols n required for this traffic... i,j and time Perform free symbol allocation based on conflict detection; During the nondeterministic source subnet processing, the skyline heuristic algorithm is used to schedule based on the remaining time slot resources of the AUTBUS backbone network and the number of symbols required by the traffic, and to determine the allocation of conflict-free idle symbols. After scheduling each traffic item in the scheduled sequence Q, the AUTBUS multi-subnet network completes the allocation of static time slot resources in the backbone network and enters the data transmission phase.

2. The resource scheduling method for AUTBUS multi-subnet networks according to claim 1, characterized in that: In an AUTBUS multi-subnet network, the traffic set F of each subnet is represented as: F = {F1, F2, F3, ..., F...} i }, F i Let F be the set of real-time periodic data traffic for subnet i, where F i ={f i,1 ,f i,2 ,...f i,j }, f i,j Let j be the j-th traffic in subnet i; each subnet has at least one traffic instance transmitted through the AUTBUS backbone. The network type parameter includes deterministic and nondeterministic networks, and each traffic item corresponds to one of these network types.

3. The resource scheduling method for AUTBUS multi-subnet networks according to claim 2, characterized in that: Extract the cross-subnet traffic flag CNF from the traffic set F. i,j =1 and period T i,j Flow f ≠ null i,j This is used to generate a scheduler sequence Q = {f} through priority mapping rules and sorting rules. i,j |CNF i,j =1,T i,j ≠null}, where the flow rate f i,j The method of obtaining it is: Encapsulate cross-subnet data transmissions into standardized AUTBUS data streams: f i,j (Src i,j ,Des i,j ,LEN i,j ,T i,j ,DR i,j ,TYPE i,j ,CNF i,j ) Among them, Src i,j It is a flow f i,j The source node; Des i,j It is a flow f i,j Destination node; LEN i,j It is a flow f i,j The frame length, in bytes; DR i,j It is a flow f i,j Maximum end-to-end allowable latency, in milliseconds. This bit is null for non-real-time periodic or non-real-time non-periodic data traffic; T i,j It is a flow f i,j The transmission period, in milliseconds. This bit is null for real-time non-periodic or non-real-time non-periodic data traffic; TYPE i,j It is a flow f i,j The type, in addition to indicating f i,j Priority, TYPE i,j The smaller the value, the higher the traffic priority (CNF). i,j For cross-subnet traffic flags, if f i,j This bit is 1 for cross-subnet traffic and 0 otherwise.

4. A resource scheduling method for AUTBUS multi-subnet networks according to claim 3, characterized in that: During the generation of the scheduler sequence Q, the priority mapping rule refers to assigning the lowest priority of non-real-time periodic data and non-real-time aperiodic data to 255, while real-time periodic data and real-time aperiodic data are prioritized based on latency requirements, as shown in the following formula: In the formula, TYPE i,j f i,j Priority, Pri max Pri represents the maximum priority in the network. min This represents the minimum priority value in the network. The priority of non-real-time periodic data and non-real-time non-periodic data is divided into 255, DR i,j f i,j The latency requirement, This represents the maximum delay requirement for each traffic stream in Q. This represents the minimum latency requirement for each traffic stream in Q; The sorting rules first rank all traffic according to priority. Secondly, for traffic with the same priority, shorter periods rank higher; for traffic with the same priority and period, shorter lengths rank higher; for traffic with the same priority, period, and length, smaller sequence numbers (i) rank higher; for traffic with the same priority, period, length, and sequence number (i), smaller sequence numbers (j) rank higher. A scheduling sequence Q = {f} is generated. i,j |CNF i,j =1,T i,j ≠null}.

5. A resource scheduling method for AUTBUS multi-subnet networks according to claim 3, characterized in that: Based on the sending period T of each traffic stream i,j The ideal fundamental period BC and the ideal scheduling period SC are calculated as follows: BC=GCD(T 1，1 ,T 1，2 ,...,T i,j ) SC=LCM(T 1，1 ,T 1，2 ,...,T i,j ) Among them, T i,j f i,j The transmission period, GCD(T) 1,1 ,T 1,2 ...T i,j ) indicates the calculation of T 1,1 ,T 1,2 ...T i,h The greatest common divisor of LCM(T) 1,1 ,T 1,2 ...T i,j ) indicates the calculation of T 1,1 ,T 1,2 ...T i,j The least common multiple; SC consists of several BCs, and all traffic in Q is transmitted at least once in an SC, with the number of transmissions and the transmission time being the same in each SC; The transmission mode m determines the duration of one AUTBUS frame, BC T This refers to the basic period of actual transmission, SC T This refers to the actual transmission scheduling period, SC T =SC; where q BCs constitute an AUTBUS frame, i.e., BC T ;p BC T This constitutes a scheduling cycle, i.e., SC T ;have: In the formula, p represents the number of AUTUS frames in a superframe, and q represents the ratio of the duration of an AUTUS frame to BC, with an initial value of 1. If the calculated p > 8, then q is increased by 1, and p is calculated again until p ≤ 8. The transmission mode m is based on BC T It is confirmed that the value of m corresponds to the duration of the AUTBUUS frame.

6. A resource scheduling method for AUTBUS multi-subnet networks according to claim 1, characterized in that: Each traffic f i,j The number of time slot symbols occupied by the transmission window, n i,j The calculation method is as follows: In the formula, n i,j f i,j The number of symbols occupied by the transmission window, LEN i,j f i,j The frame length is k, where k is the number of bytes carried by a symbol. If the k is not divisible by k, it is rounded up. Each node resource is allocated a time slot as a pilot signal.

7. A resource scheduling method for AUTBUS multi-subnet networks according to claim 1, characterized in that: During the deterministic source subnet processing, the traffic set F of subnet i is... i The set of traffic F destined for subnet i. i′ As input, the scheduling algorithm of the corresponding subnet is invoked to calculate the transmission path, resource allocation scheme, and the initial time τ of each traffic flow. i,j Further f i,j The theoretical delay from the source node sending the message to the source subnet gateway preparing to send it. The time it takes for each traffic item in the deterministic source subnet to reach the source subnet gateway is calculated. During the cyclic collision detection process, according to and n i,j Detect f i,j If a conflict occurs with the symbol resources required by other traffic, the system checks for conflicts. If a conflict occurs, the system shifts to the next available symbol, checks for conflicts again, and if a conflict still occurs, shifts to the next available symbol. This process is repeated until f is detected. i,j This free symbol does not conflict with the symbol resources required by other traffic, and will contain the free symbol and the (n) symbol following it. i,j -1) symbols are assigned to f i,j ; If not enough time slots are allocated to f during the entire scheduling cycle i,j Then determine f i,j Scheduling failed.

8. A resource scheduling method for AUTBUS multi-subnet networks according to claim 1, characterized in that: During the processing of nondeterministic source subnets, scheduling is performed based on the remaining time slot resources of the AUTBUS backbone network and the number of symbols required by the traffic to determine conflict-free idle symbols. If not enough time slots are allocated to f during the entire scheduling cycle i,j Then f i,j Scheduling failed; the process of the skyline heuristic algorithm is as follows: First, read the traffic f. i,j The resource requirements are determined, and then a rectangular space with length l and width s is initialized. The length l represents the number of symbols that the user can use per frame; the width s = p means that p frames form a scheduling cycle. Then, the resources occupied by the real-time periodic data traffic are removed to obtain the remaining resource set; Traverse the set of remaining resources. If no remaining resource that meets the resource requirements is found, the scheduling fails. If a remaining resource that meets the resource requirements is found, allocate the resource to the traffic, split the remaining part into two parts, add them to the set of remaining resources respectively, and finally delete the resource from the set of remaining resources and output the scheduling result.

9. A resource scheduling method for AUTBUS multi-subnet networks according to claim 1, characterized in that: After traffic resource scheduling for deterministic and non-deterministic source subnets is completed, if the destination subnet is a deterministic destination subnet, the scheduling calculation module calls the corresponding subnet's scheduling algorithm to schedule the deterministic destination subnet; if the destination subnet is a non-deterministic subnet, it is not scheduled.

10. A resource scheduling method for AUTBUS multi-subnet networks according to claim 9, characterized in that: During the data transmission phase, the subnet transmits additional real-time aperiodic data and non-real-time aperiodic data. The subnet's gateway sends a resource request to the AUTBUS management node MN. The MN forwards the required resource information to the collaborative scheduling system and calls the Skyline Heuristic Algorithm again to schedule the remaining symbol resources of the AUTBUS backbone network. If the remaining resources do not meet the requirements, they will not be allocated. After completing the transmission of real-time aperiodic data and non-real-time aperiodic data in the AUTBUS multi-subnet network, resources are released through two methods: MN active reclamation or gateway request for release.

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