CN110996279B - Multi-channel parallel transmission data scheduling method and system applied to unmanned aerial vehicle communication - Google Patents

Abstract

The invention discloses a multi-channel parallel transmission data scheduling method and system applied to unmanned aerial vehicle communication. In the method, the remote control terminal and the main controller of the unmanned aerial vehicle terminal simultaneously control multiple radio frequency chips to realize multi-channel parallel transmission. The sender packages the data packets to be sent into multiple data packets, and marks the data packets with a globally unique sequence number; after sending the set number of data packets, the ACK packet received by the receiving end is regarded as an estimated period for each data packet. Estimate the throughput of the transmission channel, and calculate the time for each data transmission channel to arrive at the receiving end after sending the data packet according to the throughput estimation, and assign the data packet to the fastest data transmission channel that reaches the receiving end, so that the receiving end is as ordered as possible. Receive packets. The invention avoids the problem of low throughput of the transmission channel caused by the blocking of the buffer at the receiving end, effectively utilizes the advantages of multiple data transmission channels, and improves the data transmission rate of the multi-channel parallel channels of the unmanned aerial vehicle communication.

Description

Multi-channel parallel transmission data scheduling method and system applied to unmanned aerial vehicle communication

technical field

The invention relates to a multi-channel parallel transmission data scheduling method and system applied to unmanned aerial vehicle communication, and belongs to the technical field of unmanned aerial vehicle communication.

Background technique

With the development of science and technology, the application fields of UAVs are becoming more and more extensive. From military reconnaissance, agricultural sowing, to logistics distribution, aerial photography technology, drones are playing unparalleled advantages in more and more fields. Therefore, the research on UAVs also needs to be more in-depth and achieve technological breakthroughs to meet the growing market demand. When drones are used in exploration and reconnaissance work, it is often necessary to build high-speed data transmission channels, and traditional single-chip data transmission is often difficult to support high-speed transmission scenarios. How to integrate multiple RF chips into the same main controller is an urgent requirement in the field of drones.

In the process of multi-channel parallel transmission of UAV, due to the difference in the position, attitude, transmission mode and transmission frequency of the radio frequency antenna of each transmission channel, there may be huge differences in the round-trip delay and throughput of each transmission channel. If the traditional method of sending data packets in sequence is used, it may cause the transmission delay of a transmission channel with poor performance to be long, causing the data packets to arrive at the receiving end out of sequence, which in turn causes the buffer of the receiving end to be blocked, making the UAV communicate. It is not possible to effectively utilize each transmission channel to increase the data transmission rate. Therefore, how to design an effective data scheduling mechanism to solve the problem of low data transmission rate of multi-channel parallel transmission of UAV communication is very important.

SUMMARY OF THE INVENTION

Purpose of the invention: In view of the above-mentioned deficiencies of the prior art, the purpose of the present invention is to provide a multi-channel parallel transmission data scheduling method and system applied to UAV communication. Use the main controller to control multiple RF chips at the same time to achieve multi-channel parallel transmission. According to the transmission delay, the throughput of each transmission channel is estimated in real time, and the data scheduling algorithm is used to calculate the delay of each transmission channel to the receiving end after sending the data packet, and assign the data packet to the path with the smallest delay, so that the receiving end can receive the data in order as much as possible. package to improve the transmission speed of UAV communication data.

Technical scheme: In order to realize the above-mentioned purpose, the technical scheme adopted in the present invention is:

A multi-channel parallel transmission data scheduling method applied to unmanned aerial vehicle communication, characterized in that: in the method, the remote control terminal of the unmanned aerial vehicle communication system and the main controller of the unmanned aerial vehicle terminal respectively control multiple radio frequency chips at the same time, send and receive The radio frequency chips of both parties correspond one by one to form multiple data transmission channels to realize multi-channel parallel transmission. The method includes the following steps:

(1) The sender packages the data packets to be sent into multiple data packets, and marks the data packets with a globally unique sequence number;

对每条数据传输通道的吞吐量进行估计；其中E_n是某条数据传输通道吞吐量第n次估计的结果，E_n-1是某条数据传输通道吞吐量第n-1次估计的结果，M_n是第n次估计的估计周期内发送的数据包总数，T_n是发送端在该估计周期发送第一个数据包的时刻至接收到ACK包的时刻的时间间隔，M_n与T_n的比值是该估计周期内该条数据传输通道的瞬时吞吐量大小，α为平滑因子，α随着时间间隔T_n的减小而增大，随着时间间隔T_n的增大而减小；(2) The sender takes the ACK packet fed back by the receiver after sending the set number of data packets as an estimation period, according to the formula

Estimate the throughput of each data transmission channel; where E _n is the result of the nth estimation of the throughput of a certain data transmission channel, and E _n-1 is the result of the n-1th estimation of the throughput of a certain data transmission channel , Mn is the total number of data packets sent in the estimation period of the _{nth estimation, T n is} the time interval from the moment the sender sends the first data packet in the estimation period to the moment when the ACK packet is received, _Mn and T The ratio of _n is the instantaneous throughput of the data transmission channel in the estimation period, α is a smoothing factor, α increases with the decrease of the time interval T _n , and decreases with the increase of the time interval T _n ;

(3) The sending end calculates the time when the data packet arrives at the receiving end according to the throughput estimation of each data transmission channel and the number of data packets that have been allocated, and assigns the data packet to the data transmission channel that can make the data packet arrive at the receiving end at the earliest;

(4) Each data transmission channel transmits the allocated data packets in turn, the receiving end integrates the received data packets according to the serial number, and the transmitting end adjusts the data packet allocation according to the ACK packet situation fed back by the receiving end.

In a preferred embodiment, the main controller of the remote control terminal and the UAV terminal controls multiple radio frequency chips through the serial peripheral interface SPI, and different data transmission channels use different transmission modes or transmission frequencies for one-to-one communication. , in order to achieve a communication state that is independent of each other and does not interfere with each other.

In a preferred embodiment, in the step (1), the sending end adds a header including check bits, flag bits, window size, and version number content for the data packets to be sent as data packets with equal byte lengths, and marks A globally unique serial number.

In a preferred embodiment, the value of the smoothing factor α is calculated by the following formula in the step (2):

where k is a constant, and the smoothing factor α increases with the decrease of the time interval T _n to reduce the influence of the instantaneous throughput on the estimation result and improve the stability of the estimation result; the smoothing factor α increases with the time interval T As _n increases, it decreases to enhance the influence of the instantaneous throughput on the estimation result and improve the real-time performance of the result.

的算法表示为：In a preferred embodiment, in the step (3), the sender calculates the data packets to be allocated through each data transmission by estimating the throughput of each data transmission channel and in combination with the number of allocated data packets in each channel. The time when the channel arrives at the receiving end, the data packets to be allocated are allocated to different data transmission channels; the data transmission path of the data packets to be allocated is selected

The algorithm is expressed as:

Among them, N is the number of data transmission channels, S _x is the number of data packets allocated on data transmission channel x but has not sent an acknowledgment, E _x is the latest estimated throughput on data transmission channel x, and t _x is data transmission The last time an ACK packet is received on channel x is the last time the path throughput is calculated.

In a preferred embodiment, in the step (4), each data transmission channel transmits the allocated data packets in turn independently of each other, and each radio frequency chip at the receiving end feeds back the acceptance status through an ACK packet after receiving a series of data packets; If there is a data packet that needs to be resent due to a receiving timeout or a receiving error, the sender sends the data packet first, that is, assigns it to the data transmission channel that can reach the receiver first to send data, and the scheduling priorities of other data packets are delayed in turn.

A multi-channel parallel transmission data scheduling system applied to drone communication, comprising a remote control terminal and a drone terminal, for implementing the multi-channel parallel transmission data scheduling method applied to drone communication, the remote control The main controller of the terminal and the UAV side respectively controls multiple radio frequency chips at the same time, and the radio frequency chips of the sending and receiving sides correspond one-to-one to form multiple data transmission channels to realize multi-channel parallel transmission;

对每条数据传输通道的吞吐量进行估计；根据各个数据传输通道的吞吐量估计情况以及已分配到的数据包个数计算数据包到达接收端的时间，将数据包分配给能够使数据包最早到达接收端的数据传输通道；各个数据传输通道依次传输被分配的数据包，根据接收端反馈的ACK包情况，调整数据包分配情况；When the remote control terminal or the drone terminal is used as the sending terminal, it is used to package the data packets to be sent into multiple data packets, and mark the data packets with a globally unique sequence number; The ACK packet fed back by the receiver is an estimated period, according to the formula

Estimate the throughput of each data transmission channel; calculate the time when the data packet arrives at the receiving end according to the throughput estimation of each data transmission channel and the number of allocated data packets, and allocate the data packets to the earliest possible arrival time of the data packets. The data transmission channel of the receiving end; each data transmission channel transmits the allocated data packets in turn, and adjusts the data packet allocation according to the ACK packet situation fed back by the receiving end;

When the remote control terminal or the UAV terminal is used as the receiving terminal, it is used to feed back ACK packets after receiving a set number of data packets, and integrate the received data packets according to the serial number.

Beneficial effects: Compared with the prior art, the advantages of the present invention are: using the multi-channel parallel transmission method described in the present invention to control multiple radio frequency chips simultaneously on the main controller, the data transmission rate can be significantly improved. The data scheduling mechanism described in the present invention estimates the throughput of each transmission channel in real time according to the transmission delay, calculates the time when each transmission channel sends a data packet to the receiving end, and allocates the data packet to the fastest data transmission channel that reaches the receiving end, Make the receiving end receive data packets in sequence as much as possible, avoid the problem of low throughput of transmission channels caused by buffer blocking of the receiving end, effectively utilize the advantages of multiple data transmission channels, and improve the data of multiple parallel channels of UAV communication. Transmission rate.

Description of drawings

FIG. 1 is a system model diagram of a method for scheduling data for multi-channel parallel transmission in an embodiment of the present invention;

FIG. 2 is a schematic flowchart of a method for scheduling multi-channel parallel transmission data according to an embodiment of the present invention;

FIG. 3 is a working model diagram of a multi-channel parallel transmission data scheduling module in an embodiment of the present invention.

Detailed ways

The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

As shown in FIG. 1, it is a system model diagram of a multi-channel parallel transmission data scheduling method. A multi-channel parallel transmission data scheduling system applied to UAV communication disclosed in an embodiment of the present invention includes a remote control terminal and a UAV terminal. . In order to realize the multi-channel parallel transmission method, the specific requirements are as follows: each of the remote control terminal and the UAV terminal has a main controller. The main controllers of the sending and receiving parties distribute data packets to each data transmission channel through the data scheduling module, and control multiple radio frequency chips through the serial peripheral interface SPI. Different data transmission channels use different transmission modes or transmission frequencies for one-to-one communication. , in order to achieve a communication state that is independent of each other and do not interfere with each other, and realize multi-channel parallel data transmission to improve data transmission efficiency.

As shown in Figure 2, it is a schematic flow chart of a method for scheduling multi-channel parallel transmission data. Specifically, the sender packages the data packets to be sent into multiple data packets, and marks the data packets with a globally unique sequence number; The module estimates the throughput according to the past throughput and instantaneous throughput of each data transmission channel; by calculating the time when the data packet arrives at the receiving end, the data packet is allocated to different data transmission channels; each data transmission channel is independent of each other and sequentially The allocated data packets are sent, and each radio frequency chip at the receiving end receives a series of data packets and feeds back the acceptance status through ACK packets. If there is a data packet that needs to be resent due to acceptance timeout or acceptance error, the sender sends the data packet first, that is, it is assigned to the data transmission channel that can reach the receiver first through the data scheduling module to send data, and other data Packet scheduling priorities are sequentially delayed. The receiving end integrates the received data according to the sequence number of each data packet.

As shown in Figure 3, it is the working model diagram of the multi-channel parallel transmission data scheduling module, specifically: the data scheduling module estimates the throughput of each data transmission channel, so as to receive the ACK feedback from the receiving end after sending ten data packets A packet is an estimated period, in which the number of data packets sent in the estimated period can be set in the system as required. The total number of data packets sent in the estimated period is M _n , and the sender sends the first data packet in the estimated period at the moment The time interval to the moment when the ACK packet is received _is Tn. After the ACK packet is received in each estimation period, the throughput of the data transmission channel is estimated once by the following formula.

where E _n is the result of the nth estimation of the throughput of a certain data transmission channel, the ratio of M _n to T _n is the instantaneous throughput of the data transmission channel in the estimation period, and α is the smoothing factor, which is calculated by the following formula the value of a.

where k is a constant, and the smoothing factor α increases with the decrease of the time interval T _n to reduce the influence of the instantaneous throughput on the estimation result and improve the stability of the estimation result; the smoothing factor α increases with the time interval T As _n increases, it decreases to enhance the influence of the instantaneous throughput on the estimation result and improve the real-time performance of the result.

的算法：The data scheduling module calculates the time when the data packets to be allocated arrive at the receiving end through each data transmission channel according to the estimation of the throughput of each data transmission channel, combined with the number of data packets allocated in each channel, and allocates the data packets to be allocated to the receiver. Different data transmission channels. The following formula describes the data transmission path for selecting the data packets to be allocated

Algorithm:

Among them, N is the number of data transmission channels, S _x is the number of data packets allocated on data transmission channel x but has not sent an acknowledgment, E _x is the latest estimated throughput on data transmission channel x, and t _x is data transmission The last time an ACK packet is received on channel x is the last time the path throughput is calculated. Using this data scheduling algorithm, the data packets can arrive at the receiving end in sequence as much as possible, reducing the problem of low data transmission efficiency caused by the buffer blocking of the receiving end.

Each data transmission channel transmits the allocated data packets in sequence independently of each other, and each radio frequency chip at the receiving end feeds back the acceptance status through an ACK packet after receiving a series of data packets. If there is a data packet that needs to be resent due to acceptance timeout or acceptance error, etc., the main controller of the sending end sends this data packet first, that is, it is assigned to the data transmission channel that can reach the receiving end first through the data scheduling module to send data. , the scheduling priorities of other data packets will be delayed in turn. The main controller at the receiving end integrates the received data according to the serial number of each data packet.

The above descriptions are only the preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above-mentioned embodiments, but any equivalent modifications or changes made by those of ordinary skill in the art based on the contents disclosed in the present invention should be included in the within the scope of protection described in the claims.

Claims (7)

1. a multi-channel parallel transmission data scheduling method that is applied to unmanned aerial vehicle communication, it is characterized in that: in the described method, the remote control end of the unmanned aerial vehicle communication system and the main controller of the unmanned aerial vehicle end respectively control multiple radio frequency chips simultaneously , the radio frequency chips of the sending and receiving parties are in one-to-one correspondence to form multiple data transmission channels to realize multi-channel parallel transmission. The method includes the following steps: (1) The sender packages the data packets to be sent into multiple data packets, and marks the data packets with a globally unique sequence number; (2) The sender takes the ACK packet fed back by the receiver after sending the set number of data packets as an estimation period, according to the formula

Estimate the throughput of each data transmission channel; where E _n is the result of the nth estimation of the throughput of a certain data transmission channel, and E _n-1 is the result of the n-1th estimation of the throughput of a certain data transmission channel , Mn is the total number of data packets sent in the estimation period of the _{nth estimation, T n is} the time interval from the moment the sender sends the first data packet in the estimation period to the moment when the ACK packet is received, _Mn and T The ratio of _n is the instantaneous throughput of the data transmission channel in the estimation period, α is a smoothing factor, α increases with the decrease of the time interval T _n , and decreases with the increase of the time interval T _n ; (3) The sending end calculates the time when the data packet arrives at the receiving end according to the throughput estimation of each data transmission channel and the number of data packets that have been allocated, and assigns the data packet to the data transmission channel that can make the data packet arrive at the receiving end at the earliest; (4) Each data transmission channel transmits the allocated data packets in turn, the receiving end integrates the received data packets according to the serial number, and the transmitting end adjusts the data packet allocation according to the ACK packet situation fed back by the receiving end. 2. the multi-channel parallel transmission data scheduling method applied to unmanned aerial vehicle communication according to claim 1, is characterized in that: the main controller of described remote control end and unmanned aerial vehicle end controls multiple by serial peripheral interface SPI Radio frequency chip, different data transmission channels use different transmission modes or transmission frequencies for one-to-one communication to achieve a communication state that is independent of each other and does not interfere with each other. 3. the multi-channel parallel transmission data scheduling method that is applied to unmanned aerial vehicle communication according to claim 1, is characterized in that: in described step (1), sending end is equal to the data packet of byte length for data packet to be sent , add a header including check bit, flag bit, window size, version number, and mark a globally unique serial number. 4. the multi-channel parallel transmission data scheduling method applied to UAV communication according to claim 1, is characterized in that: in described step (2), the value of smoothing factor α is calculated by following formula:

where k is a constant, and the smoothing factor α increases with the decrease of the time interval T _n to reduce the influence of the instantaneous throughput on the estimation result and improve the stability of the estimation result; the smoothing factor α increases with the time interval T As _n increases, it decreases to enhance the influence of the instantaneous throughput on the estimation result and improve the real-time performance of the result. 5. The multi-channel parallel transmission data scheduling method applied to unmanned aerial vehicle communication according to claim 1, it is characterized in that: in the described step (3), the transmitting end is based on the estimation to the throughput of each data transmission channel, combined with The number of data packets allocated in each channel, calculate the time for the data packets to be allocated to reach the receiving end through each data transmission channel, and allocate the data packets to be allocated to different data transmission channels; select the data transmission path of the data packets to be allocated.

The algorithm is expressed as:

Among them, N is the number of data transmission channels, S _x is the number of data packets allocated on data transmission channel x but has not sent an acknowledgment, E _x is the latest estimated throughput on data transmission channel x, and t _x is data transmission The last time an ACK packet is received on channel x is the last time the path throughput is calculated. 6. the multi-channel parallel transmission data scheduling method applied to unmanned aerial vehicle communication according to claim 1 is characterized in that: in the described step (4), each data transmission channel independently sends the allocated data packets successively, After receiving a series of data packets, each radio frequency chip at the receiving end feeds back the reception status through an ACK packet; if there is a data packet that needs to be resent due to a receiving timeout or a receiving error, the transmitting end sends this data packet first, that is, assigns it to the most efficient data packet. The data transmission channel that reaches the receiving end first sends data, and the scheduling priorities of other data packets are delayed in turn. 7. A multi-channel parallel transmission data dispatching system applied to unmanned aerial vehicle communication, comprising remote control terminal and unmanned aerial vehicle terminal, it is characterized in that: described system is used for realizing according to any one of claim 1-6 described A multi-channel parallel transmission data scheduling method applied to UAV communication, the remote control terminal and the main controller of the UAV terminal respectively control multiple radio frequency chips at the same time, and the radio frequency chips of the sending and receiving parties correspond one-to-one to form multiple data transmission channels , in order to realize multi-channel parallel transmission; when the remote control terminal or the UAV terminal is used as the transmitting terminal, it is used to package the data packets to be sent into multiple data packets, and mark the data packets with a globally unique serial number; After a certain number of data packets, the ACK packet received by the receiver is an estimated period, according to the formula

Estimate the throughput of each data transmission channel; calculate the time when the data packet arrives at the receiving end according to the throughput estimation of each data transmission channel and the number of allocated data packets, and allocate the data packets to the earliest possible arrival time of the data packets. The data transmission channel of the receiving end; each data transmission channel transmits the allocated data packets in turn, and adjusts the data packet distribution according to the ACK packet situation fed back by the receiving end; when the remote control end or the UAV end is used as the receiving end, it is used for After receiving the set number of data packets, the ACK packet is fed back, and the received data packets are integrated according to the sequence number.

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