A multi-channel data selection method with timing control

Abstract

The present invention relates to a multi-channel data selection method with timing control, belonging to the field of real-time data processing for aircraft. The present invention employs a circular queue connected end to end, with each data bit in the circular queue used to store the first address of a linked list; multiple linked lists are used to store received homologous data, each linked list storing data corresponding to a data packet; a queue read pointer points to the currently read circular queue data bit; and a read sequence number variable is used to store the packet sequence number of the data packet stored in the linked list corresponding to the currently read circular queue data bit. The present invention designs a data structure combining a circular queue and a bidirectional linked list, employing a specific read and write strategy, which greatly simplifies the development difficulty of a real-time data processing system and improves data utilization.

Description

Technical Field

[0001] The invention belongs to the field of real-time data processing of aircraft, and in particular relates to a multi-channel data selection method with timing control. Background Art

[0002] During flight, the aircraft transmits its internal operating status to the ground in real time. Multiple devices on the ground receive the aircraft's radio signals in real time, convert them into computer-processable data, and transmit them to the data center via Ethernet. Data packets transmitted by the same aircraft, received by different devices, are homologous and have the same sequence number. Each data packet sent to the center is a fixed-length packet containing the data sequence number and the sending device's ID. The order of transmission matches the order of the receiving aircraft's data. Upon receiving the data, the data center performs certain processing and decoding to ultimately decode the data into the aircraft's internal operating status.

[0003] Considering that the data source received by ground equipment is an aircraft in flight, the data received simultaneously by ground equipment should theoretically be identical. However, in reality, radio signals are susceptible to interference, resulting in data errors. Ground receiving devices are generally located a certain distance apart and geographically dispersed to maximize data reception time. Therefore, this data is sent to the data center via the network. Depending on the number of network nodes, network latency may occur. The center must consider the impact of this latency on data processing when processing this data.

[0004] Therefore, the data that the data center needs to process is homologous data with time sequence and different delays. The present invention designs a data structure and a corresponding access control method of a multi-way data selector based on timing control to simplify the development difficulty of real-time data processing. Summary of the Invention

[0005] (1) Technical issues to be resolved

[0006] The technical problem to be solved by the present invention is how to provide a multi-channel data selection method with timing control to solve the problem of selecting homologous data sent by multiple devices and the problem of processing data with different delays sent by different devices.

[0007] (2) Technical solution

[0008] In order to solve the above technical problems, the present invention proposes a multi-way data selection method with timing control, which uses two linked list structures and two variables, wherein the two linked list structures include: a circular queue and an ordinary bidirectional linked list; the two variables include: a queue read pointer and a read sequence number variable;

[0009] The circular queue is connected end to end, and each data bit in the circular queue is used to store the first address of a linked list;

[0010] Multiple linked lists are used to store received homologous data, each linked list stores the data corresponding to a data packet;

[0011] Queue read pointer, pointing to the currently read ring queue data bit;

[0012] The read sequence number variable is used to store the packet sequence number of the data packet stored in the linked list corresponding to the currently read ring queue data bit;

[0013] When writing data, the data bit where the data to be written should be written into the circular queue is calculated based on the packet sequence number of the data to be written, the current queue read pointer of the circular queue, and the data packet sequence number in the current read sequence number variable, and the data to be written is written into the linked list corresponding to the data bit; each data packet of the same source is stored in the same linked list, and the data stored in the linked list has no priority;

[0014] When reading and processing data, the data center processes it in the order in which the data is received; when operating on a circular queue, it starts from the current queue read pointer position and reads data in sequence; after reading data once, the queue read pointer points to the next data bit in the queue, and the packet number in the read sequence variable is increased by 1; if there is data in the linked list corresponding to the data bit in the circular queue, only one data is returned to the user regardless of the amount of data.

[0015] (3) Beneficial effects

[0016] This invention proposes a multi-channel data selection method with timing control. Compared with strategic selection methods such as switching data sources by time or selecting data sources by data arrival time, this method incorporates all data received by all centers into the data selection process, improving data utilization and reliability. This method uses only queue read pointers and read sequence number variables to determine the data write location, reducing the number of circular queue write pointers and write sequence number variables and simplifying operations and increasing efficiency.

[0017] The present invention is simple to implement and can effectively select data collected and sent from multiple channels with the same source, thereby greatly simplifying the difficulty of real-time data processing for aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of a circular queue;

[0019] Figure 2 Schematic diagram of the data bit structure of the present invention;

[0020] Figure 3It is a partial expanded schematic diagram of the data bit structure of the present invention;

[0021] Figure 4 Schematic diagram of data bit calculation of the present invention. DETAILED DESCRIPTION

[0022] In order to make the purpose, content and advantages of the present invention more clear, the specific implementation methods of the present invention are further described in detail below with reference to the accompanying drawings and examples.

[0023] The design principle of the present invention is to enable the processing system to make the best possible use of the data sent by all ground devices and to eliminate the influence of the delay in sending data from different devices as much as possible.

[0024] To solve the above problems, the present invention proposes a multi-way data selection method with timing control, which uses two linked list structures and two variables. The two linked list structures include: a circular queue and an ordinary bidirectional linked list; the two variables include: a queue read pointer and a read sequence number variable.

[0025] The circular queue is connected end to end, and each data bit in the circular queue is used to store the first address of a linked list;

[0026] Multiple linked lists are used to store received homologous data, each linked list stores the data corresponding to a data packet;

[0027] Queue read pointer, pointing to the currently read ring queue data bit;

[0028] The read sequence number variable is used to store the packet sequence number of the data packet stored in the linked list corresponding to the currently read ring queue data bit.

[0029] When writing data, the data bit in the circular queue where the data should be written is calculated based on the data packet sequence number, the current queue read pointer of the circular queue, and the data packet sequence number in the current read sequence number variable. The data to be written is then written to the linked list corresponding to that data bit. All data packets from the same source are stored in the same linked list, and the data stored in the linked list has no priority.

[0030] When reading and processing data, the data center must follow the order in which the data is received. When operating on a circular queue, reads are performed sequentially, starting from the current queue read pointer position. After a data read, the queue read pointer points to the next data bit in the queue, and the packet sequence number in the read sequence variable is incremented by 1.

[0031] If there is data in the linked list corresponding to the data position in the ring queue, only one data is returned to the user regardless of the amount of data. The processing of the linked list data in the data position is as follows:

[0032] If the linked list of the current data position has only one data, the queue returns this data to the user.

[0033] If the linked list of the current data position has two data, regardless of whether the data contents are consistent, a random data is returned to the user.

[0034] If the linked list of the current data position has 3 or more data, the data content consistency is determined. If 2 or more data are found to be consistent, there is no need to determine all the data in the linked list. The consistent data is returned to the user. If all the data are different, a random data is returned to the user.

[0035] If the linked list at the current data position is empty and does not contain any data, it is considered that the data center has failed to receive the data at this position for some reason and is processed according to the non-continuous data processing method.

[0036] Example 1:

[0037] The present invention designs a multi-channel data selection method with timing control to meet the use requirements of multi-channel data with timing control from the same source.

[0038] (1) Detailed description of data structure

[0039] The present invention relates to a multi-channel data selection method with timing control, which uses two linked list structures and two variables, wherein the two linked list structures include: a circular queue and a common bidirectional linked list; the two variables include: a queue read pointer and a read sequence number variable;

[0040] The circular queue is connected end to end, and each data bit in the circular queue is used to store the first address of a linked list;

[0041] Multiple linked lists are used to store received homologous data, each linked list stores the data corresponding to a data packet;

[0042] Queue read pointer, pointing to the currently read ring queue data bit;

[0043] The read sequence number variable is used to store the packet sequence number of the data packet stored in the linked list corresponding to the currently read ring queue data bit.

[0044] The read and write control of the data bits is determined by the queue read pointer and read sequence number variables.

[0045] Figure 1 Schematic diagram of the circular queue of the present invention. During the data receiving, writing and using process, the circular queue is always operated, and the old data bits are continuously overwritten with the new data bits.

[0046] Figure 2 、 Figure 3This is a schematic diagram of the data bit structure of the present invention. Identical colors indicate identical data bits. When writing data to the same data bit, it is stored in the linked list of the same data bit and does not overwrite the data in the same position. The read and write direction represents the direction of operation of the data structure controlled by the cursor pointer.

[0047] (2) Methods of data structure initialization

[0048] The data structures and related variables involved in the multi-channel data selection method with timing control of the present invention are initialized by performing the following operations:

[0049] S11. Set the ring queue to a fixed size based on usage scenarios, data frequency, and other factors.

[0050] S12, initialize and clear the circular queue: point each data bit in the circular queue to the first address of a linked list, and the data in the bidirectional linked list is empty;

[0051] S13, the queue read pointer and read sequence number variables are set to 0;

[0052] (3) Data writing method

[0053] Before data is written, it is assumed that certain validity checks have been performed according to the rules.

[0054] S21, first packet data write

[0055] When the first packet of data is written, the data is written into the linked list corresponding to the 0 data bit, the queue read pointer is not updated and remains 0, and the sequence number of the data packet stored in the read sequence number variable is updated to the data packet sequence number of the first packet.

[0056] S22, normal data writing

[0057] When the second packet of data is written, the data is written into the linked list corresponding to the 1 data bit, the queue read pointer is updated to 1, and the sequence number of the data packet stored in the read sequence number variable is updated to the sequence number of the second packet; and so on.

[0058] S23, writing of advance data

[0059] The advanced data refers to the received data packet whose sequence number is greater than the packet sequence number in the read sequence number variable corresponding to the current queue read pointer. It is data to be processed and should be stored.

[0060] The data bits are calculated according to the following data bit calculation method, and the data is written into the linked list of the corresponding data bits. The queue read pointer is not updated, and the read sequence number variable is not updated.

[0061] S24, writing of delayed data

[0062] Lagging data refers to the sequence number of the received data packet. Due to the large network delay, it is smaller than the packet sequence number in the read sequence number variable corresponding to the current queue read pointer. This data does not need to be processed and is not stored.

[0063] The present invention only uses the queue read pointer and the read sequence number variable to determine the location where data is written, which not only reduces the circular queue write pointer and write sequence number variable, but also makes the operation simpler and more efficient.

[0064] Data bit calculation method:

[0065] like Figure 4 As shown, when writing data, it is necessary to calculate the data bit address where the received data should be stored based on the current queue read pointer and the packet sequence number in the read sequence number variable.

[0066] First calculate the sequence number difference P c , that is, the difference between the sequence number of the currently received data packet and the sequence number in the read sequence number variable corresponding to the current queue read pointer. The formula is as follows:

[0067] P c =P d -P z

[0068] Among them, P c is the sequence number difference, P d is the sequence number of the currently received data packet, P z The packet sequence number in the read sequence number variable corresponding to the current queue read pointer.

[0069] Then calculate the write data bit, that is, the position where the currently received data is written, the formula is as follows:

[0070] P R =P Y +P C

[0071] Among them, P R The data bits that should be written to the currently received data, each data bit corresponds to a linked list, P Y The data position corresponding to the current queue read pointer, P C Normally, the linked list at the position to be written should be empty. If there is data in the linked list at the writing position, it means that the length of the circular queue is too small and the number of queues in the circular queue should be increased.

[0072] (4) Data reading method

[0073] S31. Method for reading continuous data

[0074] After taking out the linked list data corresponding to the current queue read pointer, the other data in the linked list is no longer used, and the linked list is cleared to allow other new data to be written. At the same time, the queue read pointer is increased by 1, and the read sequence number variable is increased by 1.

[0075] S32. Method for reading non-continuous data

[0076] Non-continuous data refers to the processing method when the next data bit is found to be empty during data reading. The processing is carried out according to the following process.

[0077] First determine whether the data is interrupted:

[0078] Based on the packet number recorded by the current read sequence number variable, determine whether the packet numbers recorded at the queue read pointer + 1 are continuous. If they are continuous, read them according to the continuous data reading method.

[0079] If the data at cursor position + 1 is empty, then continue to determine whether the data bit at cursor position + 2 is empty.

[0080] If there is data within the 1 / 2 ring queue, and the difference between the data bit and the current queue read pointer is exactly equal to the packet sequence number, the received data is missing. When reading data, the information in the linked list corresponding to the data bit is directly returned. The queue read pointer then points to the data bit, and the packet sequence number in the read sequence number variable is modified.

[0081] If there is no valid data in the 1 / 2 ring queue, it means that the data has been interrupted and subsequent data cannot be read. In this case, the ring queue is reinitialized.

[0082] S33, Reading strategy for multiple data packets with the same data bit

[0083] When reading data at a certain position in the circular queue, if the doubly linked list it points to contains one or more data, a valid data packet should be returned according to different situations.

[0084] Case 1: There is only one data packet, and the data is returned;

[0085] Case 2: There are 2 data packets, and one is returned randomly;

[0086] Case 3: When there are more than 3 packets, the consistency of the content is judged and the data packet with the most consistency is returned; if the consistency is different, a random data packet is returned.

[0087] Example 2:

[0088] A multi-channel data selection method with timing control uses a data structure combining a ring queue and a bidirectional linked list to store data of the same source but with different delay time characteristics.

[0089] In the selector, the circular queue is used to store data points pointing to a doubly linked list, as well as a cursor pointer and the packet sequence number of downlink aircraft data. The doubly linked list is used to store downlink aircraft data with the same packet sequence number sent from different devices. For example, the number 2 in the circular queue indicates the storage of the downlink aircraft packet number 2 and the corresponding linked list pointer. Furthermore, the doubly linked list positions 1, 2, 3, and so on, pointed to by position 2 in the circular queue, identify the data value of downlink aircraft packet number 2 from device 1.

[0090] Furthermore, the method for writing data to the selector is as follows:

[0091] Before data is written, it is assumed that certain validity checks have been performed according to the rules.

[0092] 1) First packet data is written

[0093] When the first packet of data is written, the data is written into the linked list with data bit 0, and the data cursor is not updated and remains 0. The sequence number of the data packet is updated to the sequence number of the first packet.

[0094] 2) Writing of advanced data

[0095] The advanced data refers to the received data packet whose sequence number is greater than the sequence number of the packet at the current cursor position. It is data to be processed and should be stored.

[0096] Calculate the data bits according to rule 4 and write the data into the data linked table of the corresponding data bits. The data cursor and data packet sequence number are not updated.

[0097] 3) Writing of delayed data

[0098] Lagging data refers to the sequence number of the received data packet. Due to the large network delay, it is smaller than the sequence number of the packet at the current cursor position. It is no longer used data and is directly discarded.

[0099] 4) Data bit calculation method

[0100] like Figure 4 As shown, when writing data, it is necessary to calculate the data bit address where the received data should be stored based on the current cursor position and the packet sequence number.

[0101] First calculate the sequence number difference P c , that is, the sequence number of the currently received data packet and the sequence number of the packet recorded at the current cursor position. The formula is as follows:

[0102] P c =P d -P z

[0103] Among them, P c is the sequence number difference, Pd is the sequence number of the currently received data packet, P z The packet number of the record where the current cursor is located.

[0104] Then calculate the write data bit, that is, the position where the current received data is written, the formula is as follows:

[0105] P R =P Y +P C

[0106] Among them, P R The location where the currently received data should be written, P Y is the current cursor position, P C The serial number difference.

[0107] Furthermore, the data reading method

[0108] 1) Continuous data reading method

[0109] Take out the linked list data pointed to by the current cursor position, then clear the linked list, and at the same time increase the cursor position by 1 and the data packet number by 1.

[0110] 2) Method for reading non-continuous data

[0111] Non-continuous data refers to the processing method when the next data bit is found to be empty during data reading. The processing is carried out according to the following process.

[0112] First determine whether the data is interrupted:

[0113] Based on the packet number recorded at the current cursor position, determine whether the packet numbers recorded at the cursor position + 1 are continuous. If they are continuous, read them according to the continuous data reading method.

[0114] If the data at cursor position + 1 is empty, then continue to determine whether the data bit at cursor position + 2 is empty.

[0115] If there is data within the 1 / 2 ring queue, and the difference between the data bit and the current cursor position is exactly equal to the packet sequence number, it means that the received data is missing. When reading data, the data bit information of the data is directly returned. Then the cursor points to the data bit with data.

[0116] If there is no valid data in the 1 / 2 ring queue, it means that the data has been interrupted and subsequent data cannot be read. In this case, the ring queue is reinitialized.

[0117] 3) Reading strategy for multiple data packets with the same data bit

[0118] When reading data at a certain position in the circular queue, if there are multiple data packets in the doubly linked list it points to, valid data packets should be returned according to different situations.

[0119] Case 1: There is only one data packet, and the data is returned;

[0120] Case 2: There are 2 data packets, and one is returned randomly;

[0121] Case 3: When there are more than 3 packets, the consistency of the content is judged and the data packet with the most consistency is returned; if the consistency is different, a random data packet is returned.

[0122] The present invention proposes a multi-channel data selection method with timing control. Compared with strategic selection methods such as switching data sources by time and selecting data sources by data arrival time, the present invention involves all data received by all centers in the data selection process, thereby improving data utilization and reliability.

[0123] The present invention only uses the queue read pointer and the read sequence number variable to determine the location where data is written, which not only reduces the circular queue write pointer and write sequence number variable, but also makes the operation simpler and more efficient.

[0124] The present invention is simple to implement and can effectively select data collected and sent from multiple channels with the same source, thereby greatly simplifying the difficulty of real-time data processing for aircraft.

[0125] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A multi-channel data selection method with timing control, characterized in that: The method uses two linked list structures and two variables, wherein the two linked list structures include: a circular queue and a common bidirectional linked list; the two variables include: a queue read pointer and a read sequence number variable; The circular queue is connected end to end, and each data bit in the circular queue is used to store the first address of a linked list; Multiple linked lists are used to store received homologous data, each linked list stores the data corresponding to a data packet; Queue read pointer, pointing to the currently read ring queue data bit; The read sequence number variable is used to store the packet sequence number of the data packet stored in the linked list corresponding to the currently read ring queue data bit; When writing data, the data bit where the data to be written should be written into the circular queue is calculated based on the packet sequence number of the data to be written, the current queue read pointer of the circular queue, and the data packet sequence number in the current read sequence number variable, and the data to be written is written into the linked list corresponding to the data bit; each data packet of the same source is stored in the same linked list, and the data stored in the linked list has no priority; When reading and processing data, the data center processes it in the order in which the data is received; when operating on a circular queue, it starts from the current queue read pointer position and reads data in sequence; after reading data once, the queue read pointer points to the next data bit in the queue, and the packet number in the read sequence variable is increased by 1; if there is data in the linked list corresponding to the data bit in the circular queue, only one data is returned to the user regardless of the amount of data.

2. The multi-channel data selection method with timing control according to claim 1, wherein: The method also includes, during initialization, performing the following operations: S11. Set the ring queue to a fixed size based on the usage scenario and data frequency. S12, initialize and clear the circular queue: point each data bit in the circular queue to the first address of a linked list, and the data in the bidirectional linked list is empty; S13. Set the queue read pointer and read sequence number variables to 0.

3. The multi-channel data selection method with timing control according to claim 2, wherein: When writing data, the method specifically includes: S21, first packet data write When the first packet of data is written, the data is written to the linked list corresponding to the 0 data bit, the queue read pointer is not updated and remains 0, and the sequence number of the data packet stored in the read sequence number variable is updated to the sequence number of the first packet; S22, normal data writing When the second packet of data is written, the data is written into the linked list corresponding to the 1 data bit, the queue read pointer is updated to 1, and the sequence number of the data packet stored in the read sequence number variable is updated to the sequence number of the second packet; and so on; S23, writing of advance data Leading data refers to the received data packet whose sequence number is greater than the sequence number in the read sequence number variable corresponding to the current queue read pointer. It is data to be processed and should be stored. The data bit is calculated according to the data bit calculation method and written into the linked list of the corresponding data bit. The queue read pointer is not updated, and the read sequence number variable is not updated either. S24, writing of delayed data Lagging data refers to data packets whose sequence numbers are smaller than the sequence numbers in the read sequence number variable corresponding to the current queue read pointer. These data are data that do not need to be processed and are not stored.

4. The multi-channel data selection method with timing control according to claim 3, wherein: The data bit calculation method includes: When writing data, the data bit address where the received data should be stored is calculated based on the current queue read pointer and the packet sequence number in the read sequence number variable; First, calculate the sequence number difference P c , that is, the difference between the sequence number of the currently received data packet and the sequence number in the read sequence number variable corresponding to the current queue read pointer. The formula is as follows: P c =P d -P z Among them, P c is the sequence number difference, P d is the sequence number of the currently received data packet, P z The packet sequence number in the read sequence number variable corresponding to the current queue read pointer; Then, calculate the write data bit, that is, the position where the currently received data is written, the formula is as follows: P R =P Y +P C Among them, P R The data bits that should be written to the currently received data, each data bit corresponds to a linked list, P Y The data position corresponding to the current queue read pointer, P C The serial number difference.

5. The multi-channel data selection method with timing control according to claim 4, characterized in that: When advance data is written, under normal circumstances, the linked list of the position to be written should be empty. If there is data in the linked list of the writing position, it means that the length of the circular queue is too small and the number of queues in the circular queue should be increased.

6. The multi-channel data selection method with timing control according to any one of claims 1 to 5, characterized in that: When reading and processing data, this method specifically includes: S31. Method for reading continuous data After taking out the linked list data corresponding to the current queue read pointer, the other data in the linked list is no longer used, and the linked list is cleared to allow other new data to be written. At the same time, the queue read pointer is increased by 1, and the read sequence number variable is increased by 1; S32. Method for reading non-continuous data Non-continuous data refers to the processing method when the next data bit is found to be empty during data reading. The processing is carried out according to the following process: First determine whether the data is interrupted: Based on the packet number recorded by the current read sequence number variable, determine whether the packet numbers recorded at the queue read pointer + 1 are continuous. If they are continuous, read them according to the continuous data reading method. If the data at cursor position + 1 is empty, continue to check whether the data bit at cursor position + 2 is empty; if there is data in the 1 / 2 ring queue, and the data bit with data minus the current queue read pointer is exactly equal to the packet sequence number, it means that the received data is missing; when reading data, directly return the information in the linked list corresponding to the data bit with data; then the queue read pointer points to the data bit with data, and the packet sequence number of the read sequence number variable is modified; If there is no valid data in the 1 / 2 ring queue, it means that the data has been interrupted and subsequent data cannot be read; at this time, the ring queue is reinitialized.

7. The multi-channel data selection method with timing control according to claim 6, wherein: When reading data at a certain position in the circular queue, if the doubly linked list it points to contains one or more data, a valid data packet should be returned according to different situations; if the linked list at the current data position is empty and there is no data, it is considered that the data center has failed to receive the data at this position for some reason, and it is processed according to the non-continuous data processing method.

8. The multi-channel data selection method with timing control according to claim 7, wherein: If the linked list of the current data position has only one data, the queue returns this data to the user.

9. The multi-channel data selection method with timing control according to claim 7, wherein: If the linked list of the current data position has two data, regardless of whether the data contents are consistent, a random data is returned to the user.

10. The multi-channel data selection method with timing control according to claim 7, wherein: If the linked list of the current data position has 3 or more data, the data content consistency is determined. If 2 or more data are found to be consistent, there is no need to determine all the data in the linked list. The consistent data is returned to the user. If all the data are different, a random data is returned to the user.

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