阅读说明：本技术 飞行器的航空电子系统和飞行器 (Avionics system of an aircraft and aircraft ) 是由 多米尼克·波尔特 西尔万·索旺 吉勒·拉蒂格 贝特朗·德艾 塞巴斯蒂安·勒菲弗 于 2020-11-11 设计创作，主要内容包括：本发明涉及飞行器的航空电子系统和飞行器。一种飞行器(1)的航空电子系统(10)包括航空电子计算机组(121c,121m…124c,124m)和与每个航空电子计算机相关联的交换机(SW)。对于所述航空电子计算机组中的每个航空电子计算机,所述航空电子系统包括与此航空电子计算机相关联的所述交换机和与其他航空电子计算机相关联的交换机中的每个交换机之间的通信链路。每个交换机被配置成使得它以仅基于接收这些数据帧的所述输入端口而预先限定的方式将在其输入端口上接收的所述数据帧路由到其输出端口。各个交换机被配置成使得,当航空电子计算机发送数据帧时,此数据帧被发送到所有其他航空电子计算机。(The invention relates to an avionics system of an aircraft and to an aircraft. An avionics system (10) of an aircraft (1) comprises a group of avionics computers (121c, 121m … 124c, 124m) and a Switch (SW) associated with each avionics computer. For each avionic computer in the set of avionic computers, the avionic system includes a communication link between the switch associated with that avionic computer and each of the switches associated with the other avionic computers. Each switch is configured such that it routes the data frames received on its input port to its output port in a manner predefined based only on the input port receiving those data frames. Each switch is configured such that when an avionic computer transmits a data frame, this data frame is transmitted to all other avionic computers.)

1. An avionics system (10) of an aircraft (1), comprising:

-a set of avionic computers (121c, 121m … 124c, 124 m); and

-a Switch (SW) associated with each of the set of aerial computers, each switch comprising a set of input ports and a set of output ports (S, C, 1, 2, 3);

characterized in that, for each avionic computer in the set of avionic computers, the avionic system comprises a communication link between the exchange associated with this avionic computer and each of the exchanges associated with the other avionic computers in the set of avionic computers,

and is characterized in that:

-each switch is configured such that it routes the data frames received on its input port to its output port in a manner predefined only on the basis of the input port on which they were received; and is

-each of said switches is configured such that, when an avionic computer transmits a data frame via the switch associated with said avionic computer, said data frame is transmitted to all other avionic computers in said set of avionic computers.

2. The system of claim 1, wherein the switch associated with each avionic computer is integrated into the avionic computer.

3. A system according to claim 1, characterized in that said group of avionic computers comprises pairs (121, 122, 123, 124) of avionic computers, so that each pair of avionic computers comprises a first Computer (COM) operating in a control mode and a second computer (MON) operating in a monitoring mode to monitor said first computer, and in that for each pair of computers the exchange associated with said first computer is also the exchange associated with said second computer.

4. A system according to any one of the preceding claims, characterized in that a maximum bandwidth is allocated to each input port of each Switch (SW) associated with an avionic computer, and the switch is configured to monitor the reception of data frames on an input port and reject a received frame if the maximum bandwidth allocated to the input port is exceeded.

5. The system according to the preceding claim, wherein the switch is configured to monitor the reception of data frames on an input port according to the token bucket principle.

6. The system of claim 4, wherein the system is configured to allow transmission of a number N of data streams via an input port of a switch, N being an integer greater than 1, and wherein the switch is configured to monitor receipt of data frames on the input port according to token bucket principles by implementing N token bucket counters, the counter having the highest value being decremented upon receipt of a data frame on the input port if the highest value is high enough to authorize receipt of the data frame.

7. System according to any one of the preceding claims, characterized in that the data frames exchanged between the avionic computers in the set of avionic computers have the same size corresponding to a predetermined size.

8. The system according to the preceding claim, characterized in that a switch associated with an avionic computer is configured to refuse to receive a data frame on an input port if the size of the data frame differs from the predetermined size.

9. A system according to any one of the preceding claims, wherein data frames exchanged between avionic computers in the set of avionic computers are in accordance with the ARINC 664 part 7 standard.

10. The system of any preceding claim, wherein all of the switches are similarly configured to route the data frame received on an input port of the switch to an output port of the switch in a manner predefined based only on the input port on which the data frame was received.

11. The system according to any one of the preceding claims, characterized in that it corresponds to a flight control system of the aircraft and in that the avionic computers in the set of avionic computers are flight control computers of the aircraft.

12. An aircraft (1), characterized in that it comprises an avionics system according to any one of the preceding claims.

Technical Field

The invention relates to the field of communication between avionic computers of an avionics system of an aircraft.

Background

The aircraft has avionic computers such as flight control computers, FMS (flight management system) flight management computers, FWS (flight warning system) warning management computers, etc. These avionic computers typically communicate with each other via a communications network of the aircraft, such as that in accordance with the ARINC 664 part 7 standard. Such a communication network is a deterministic switched ethernet network using virtual links, which makes it possible to guarantee the transmission of data frames between computers with guaranteed delay times. When a data frame is received by a switch on an input port, the switch analyzes the frame to determine the corresponding virtual link, and then the switch determines the output port on which the data frame should be retransmitted based on a routing table stored in memory. However, in some specific cases, in particular in the case of avionics systems (such as flight control systems) with a limited number of avionic computers, such communication networks are costly to implement. In particular, it requires the configuration of routing tables in the switch corresponding to the various virtual links. In addition, the mass and volume of the switch increases the cost of the aircraft.

Disclosure of Invention

The present invention aims in particular to provide a solution to this problem. The invention relates to an avionics system of an aircraft, comprising:

-a set of avionic computers and

-a switch associated with each of the set of aerial computers, each switch comprising a set of input ports and a set of output ports.

Avionics system it is worth noting that, for each avionic computer in said set of avionic computers, said avionics system comprises a communication link between said exchange associated with this avionic computer and each of the exchanges associated with the other avionic computers in said set of avionic computers,

and is characterized in that:

-each switch is configured such that it routes the data frames received on its input port to its output port in a manner predefined only on the basis of the input port on which they were received; and is

-each of said switches is configured such that, when an avionic computer transmits a data frame via the switch associated with said avionic computer, said data frame is transmitted to all other avionic computers in said set of avionic computers.

The routing of data frames received by the switch is thus simplified compared to the prior art, since data frames received by the switch are routed in a predefined manner based only on the input port receiving such data frames. Thus, the switch does not have to analyze the content of the received data frames to route them. In addition, it is not necessary to configure a routing table for the virtual links in the switch. Although simplified, the routing of data frames is by no means a uniform route. In particular, the predefined aspect of the routing is different for at least two input ports of the switch. Thus, the routing is predefined such that for different first and second ports of the switch, received frames are routed to at least one third port different from the first or second port only when these frames are received by the first port or, additionally (exclusively or) by the second port. For example, if routing is predefined such that a frame received by a first port is routed to this third port, then this routing is such that a frame received by a second port is not routed to this third port (or vice versa). However, this does not exclude that there may also be a fourth port to which received frames received by both the first port and the second port are routed.

In one embodiment, the switch associated with each avionic computer is integrated into the avionic computer.

In a particular embodiment, the set of avionic computers comprises pairs of avionic computers, such that each pair of avionic computers comprises a first computer operating in a control mode and a second computer operating in a monitoring mode to monitor the first computer, and for each pair of computers, the switch associated with the first computer is also the switch associated with the second computer.

In one embodiment, a maximum bandwidth is allocated to each input port of each switch associated with an avionic computer, and the switch is configured to monitor the reception of data frames on an input port and reject received frames if the maximum bandwidth allocated to this input port is exceeded. In particular, according to a first alternative, the switch is then configured to monitor the reception of data frames on the input ports according to the token bucket principle. According to a second alternative, the avionics system is configured to allow transmission of a number N of data streams via an input port of a switch, N being an integer greater than 1, and the switch is configured to monitor reception of data frames on the input port according to the token bucket principle by implementing N token bucket counters, the counter having the highest value being decremented upon reception of a data frame on the input port if the highest value is high enough to authorize reception of the data frame.

In one embodiment, the data frames exchanged between the avionic computers in the set of avionic computers have the same size corresponding to a predetermined size. Advantageously, the switch associated with the avionic computer is configured to refuse to receive a data frame on an input port if the size of said data frame differs from said predetermined size.

In a particular embodiment, the data frames exchanged between the avionic computers in said set of avionic computers are in accordance with the ARINC 664 part 7 standard.

Advantageously, all of the switches are similarly configured to route the data frame received on an input port of the switch to an output port of the switch in a manner predefined based only on the input port on which the data frame was received.

In a particular embodiment, the avionics system corresponds to a flight control system of the aircraft, and the avionics computers in the avionics computer group are flight control computers of the aircraft. The invention also relates to an aircraft comprising such an avionics system.

Drawings

The invention will be better understood by reading the following description and examining the accompanying drawings.

Fig. 1 is a view of an aircraft including an avionics system according to one embodiment of the present invention.

Figure 2A schematically illustrates an avionics system in accordance with one embodiment of the present invention.

Fig. 3A illustrates a configuration of a switch of the avionics system illustrated in fig. 2A.

Figure 2B schematically illustrates an avionics system in accordance with another embodiment of the present invention.

Fig. 3B illustrates a configuration of a switch of the avionics system illustrated in fig. 2B.

Detailed Description

The avionics system 10 shown in fig. 2A comprises a set of avionics computers 121c, 121m, 122c, 122m, 123c, 123m, 124c, 124 m. As shown in fig. 1, the avionics system 10 is integrated, for example, into an avionics bay 2 of an aircraft 1. The avionics bay 2 is located, for example, in the vicinity of the cockpit 3 of the aircraft. In the particular example shown in FIG. 2A, the avionics computer is an avionics computer of a flight control system of an aircraft. The computers are then grouped together in pairs 121, 122, 123, 124, each pair comprising first computers 121c, 122c, 123c, 124c, which are marked COM in the figure and operate in a control mode. Each pair comprises second computers 121m, 122m, 123m, 124m, which are marked MON in the figure and operate in a monitoring mode monitoring the first computer operating in the control mode. The control mode and the monitoring mode are such that when the considered pair of computers is activated, both the first computer COM operating in the control mode and the second computer MON operating in the monitoring mode determine similar flight control commands. The commands for controlling the actuators of the aircraft are commands from the first computer COM operating in the control mode. The command from the second computer MON operating in monitoring mode is compared with the command from the first computer COM and if the difference between the command from the first computer and the similar command from the second computer is greater than a predetermined threshold value, the pair of computers is declared as faulty. Then, the pair of computers becomes inactive and the other pair of computers becomes inactive in its place.

Each avionic computer includes a processing unit labeled "Proc" in the figure. This processing unit comprises, for example, a microprocessor or microcontroller. Each avionic computer also includes a switch (labeled SW in the figure) of the communications network. In the example illustrated in the figure, this switch has 5 bidirectional communication ports (labeled S, C, 1, 2, 3 in the figure). However, other numbers of communication ports are contemplated without departing from the scope of the present invention. The communication port S is connected to the communication port of the processing unit Proc of the aircraft computer in question. According to a first alternative, the processing unit Proc of the avionic computer and the switch SW are located on the same electronic board. According to a second alternative, the processing unit Proc and the switch SW of the avionic computer are located on two separate electronic boards, integrated into the same physical casing and supplied with power by the same power supply.

For each pair 121, 122, 123, 124 of avionic computers, according to an alternative, the first computer COM operating in the control mode and the second computer MON operating in the monitoring mode are integrated into separate physical housings. According to another alternative, the first computer COM operating in the control mode and the second computer MON operating in the monitoring mode are integrated into the same physical casing.

The switches SW of two computers COM and MON of the same pair are connected to each other by their corresponding ports marked C. In the example illustrated in fig. 2A, ports 1, 2, 3 of the switch SW of the computer COM of each pair of avionic computers 121, 122, 123, 124 of the pair are connected to ports of the switch SW of the computer COM of the other pair of avionic computers.

Each switch SW is configured such that it routes data frames received on its input port to its output port in a manner predefined based only on the input port on which they were received. Fig. 3A shows a configuration common to the respective switches SW of fig. 2A. Fig. 3A illustrates the routing of data frames received on each input port of the switch to an output port of the switch. Thus, a data frame received on input port S is routed to 4 output ports C, 1, 2, 3. A data frame received on input port C is routed to 4 output ports S, 1, 2, 3. A data frame received on any of input ports 1, 2, or 3 is routed to 2 output ports C and S.

As illustrated in fig. 2A, the configuration of the above-described set of links of each switch coupled between switches enables a communication link to be established between each switch associated with an avionic computer and each switch associated with other avionic computers in the set of avionic computers. This configuration of the individual switches is such that, when an avionic computer transmits a data frame via the switch associated with this avionic computer, this data frame is transmitted to all other avionic computers in the avionic computer group. Thus, for example, when an avionic computer 121c sends a data frame to its associated switch SW, the data frame is received by the switch via its communication port S. As described above with reference to fig. 3A, the switch routes this data frame to its output ports C, 1, 2 and 3. A data frame routed to output port C is received by input port C of the switch associated with computer 121m, which routes the data frame to its output port S destined for computer 121 m. A data frame routed to output port 1 of the switch associated with computer 121C is received by input port 1 of the switch associated with computer 123C, which first routes the data frame to its output port S destined for computer 123C and then to its output port C destined for the switch associated with computer 123 m. The switch receives the data frame on its input port C and the switch routes the data frame to its output port S destined for computer 123 m. A data frame routed to output port 2 of the switch associated with computer 121C is received by input port 1 of the switch associated with computer 122C, which first routes the data frame to its output port S destined for computer 122C and then to its output port C destined for the switch associated with computer 122 m. The switch receives the data frame on its input port C and the switch routes the data frame to its output port S to computer 122 m. A data frame routed to output port 3 of the switch associated with computer 121C is received by input port 1 of the switch associated with computer 124C, which first routes the data frame to its output port S destined for computer 124C and then to its output port C destined for the switch associated with computer 124 m. The switch receives the data frame on its input port C and the switch routes the data frame to its output port S destined for computer 124 m. Thus, any data frame sent by computer 121c to its associated switch SW is sent to all the other avionic computers of avionics system 10. Similarly, any data frame transmitted by any other avionic computer 121m, 122c, 122m, 123c, 123m, 124c, 124m is transmitted to all other avionic computers of the avionic system 10.

Advantageously, the data frames exchanged between the avionic computers in the set of avionic computers are in accordance with the ARINC 664 part 7 standard. Although these data frames use virtual links, the switches associated with the avionics computers of the avionics system 10 do not decode these data frames. As described above, the data frame transmitted by an avionic computer in the set of avionic computers is transmitted to all other avionic computers in the set of avionic computers. Upon receiving the data frames, the avionic computer checks whether the data frames are destined for them, and they filter frames for which they are not the intended recipient. This enables the routing of data frames to be facilitated through the various switches, since they perform the same routing regardless of their location in the avionics system 10. In addition, the switches do not need to analyze the received data frames to decode the corresponding virtual links in order to retransmit the data frames based on the routing table. Thus simplifying the switch. In addition, the integration of the switch into the avionics computer enables the implementation of the avionics system 10 to be simplified.

In a variant embodiment of the avionics system 10 shown in fig. 2B, the switches SW associated with the avionics computers each have 5 bidirectional communication ports (referenced S, C, G, 1, 2 in the figure). The communication port S of each switch is connected to the communication port of the processing unit Proc of the aircraft computer associated with this switch. The switches SW of the two computers COM and MON of the same pair are connected to each other firstly through their respective ports marked C and secondly through their respective ports marked G. In the example illustrated in fig. 2B, three of the ports 1, 2 of the switch SW of the computers COM and MON of each of the pairs of avionic computers 121, 122, 123, 124 are connected to the ports of the switch SW of the computers COM and MON of the other pairs of avionic computers.

Each switch SW is configured such that it routes data frames received on its input port to its output port in a manner predefined based only on the input port on which they were received. Fig. 3B shows a configuration common to the respective switches SW of fig. 2B. Fig. 3B shows the routing of data frames received on each input port of the switch to an output port of the switch. Thus, a data frame received on input port S is routed to 4 output ports C, G, 1, 2. A data frame received on input port C is routed to output port S. Data frames received on input port G are routed to output ports 1 and 2. A data frame received on one of input ports 1 or 2 is routed to 2 output ports C and S.

As illustrated in fig. 2B, the configuration of the above-described set of links of each switch coupled between switches enables a communication link to be established between each switch associated with an avionic computer and each switch associated with other avionic computers in the set of avionic computers. This configuration of the individual switches is such that, when an avionic computer transmits a data frame via the switch associated with this avionic computer, this data frame is transmitted to all other avionic computers in the avionic computer group, as in the avionic systems illustrated in fig. 2A and 3A.

In a particular embodiment not shown in the figures, for each pair of avionic computers COM and MON, the switch associated with the computer COM is also the switch associated with the computer MON. This enables a single switch to be implemented that is common to both computers in each pair.

In an advantageous embodiment, the maximum bandwidth is allocated to each input port of each switch SW associated with the avionic computer. The switch is then configured to monitor receipt of data frames on the input port and reject received frames if the maximum bandwidth allocated to the input port is exceeded. The maximum bandwidth may be characterized by a minimum time interval, also called BAG (bandwidth allocation gap), between two consecutive data frames of the data stream. In particular, the maximum bandwidth is characterized by a maximum jitter value in addition to the BAG. These concepts of BAG and jitter are similar to those used in communication networks according to the ARINC 664 part 7 standard. In particular, the switch is configured to monitor for receipt of data frames on the input ports according to the token bucket principle. According to this principle, the counter is incremented according to a predefined time period. When a data frame is received on the input port of the considered switch, the counter is decremented by a predetermined value if the current value of the counter is greater than or equal to said predetermined value. The switch then accepts the received data frame. If not, the switch rejects the received data frame by not retransmitting the data frame on any of its output ports when the current value of the counter is less than the predetermined value. The predetermined value corresponds to a value of the BAG. Depending on the value of the jitter, the increment of the counter at each time period saturates: for a zero jitter value, the counter saturates at the predetermined value corresponding to the BAG. Thus, when the counter is decremented by the predetermined value upon authorization to receive a data frame, its value returns to zero. It is then necessary to wait for at least a duration corresponding to the BAG in order to be able to accept the reception of a new data frame, which in fact corresponds to the definition of a jitter value of zero. For positive jitter values, the saturation value of the counter is equal to the predetermined value corresponding to the BAG plus the value corresponding to the jitter. Therefore, after the reception of the data frame is authorized, in the case where the counter is decremented by the predetermined value, the value thereof is returned to the value corresponding to the jitter.

In particular, when the avionics system is configured so that an input port of the switch SW should receive N data streams (N being an integer greater than 1), the reception of data frames on this input port is monitored by implementing N counters similar to those described above for the token bucket principle. When the data frame is in accordance with ARINC 664 part 7 standard, the N data streams may, for example, correspond to N virtual links. Each of the N counters is incremented at each time period. When a data frame is received, the one of the N counters having the highest current value among the current values of the N counters is considered. The principle of accepting or rejecting received data frames is implemented based on this counter, similar to the above-described principle implemented with a single counter of a conventional token bucket. Thus, if the current value of this counter is greater than or equal to a predetermined value, the counter is decremented by the predetermined value. The switch then accepts the received data frame. If not, the switch rejects the received data frame by not retransmitting the data frame on any of its output ports when the current value of the counter is less than the predetermined value. Implementing N counters enables accurate monitoring of the jitter of the BAG and the N traffic streams that the communication ports of the switch are capable of receiving.

In particular, all data frames exchanged between the avionic computers in the set of avionic computers have the same size corresponding to a predetermined size. Advantageously, the switch associated with the avionic computer is configured to refuse to receive a data frame on an input port if the size of said data frame differs from said predetermined size.

As in the case of a communication network according to the ARINC 664 part 7 standard, the avionics system according to the invention can perform a mathematical analysis of the flows on its respective communication links to determine the maximum end-to-end delays of the various links between the devices of the avionics system (thus enabling verification of whether these delays are in accordance with the specifications of the avionics system) and to determine the minimum required size of each buffer associated with the respective communication port. This mathematical analysis also enables the maximum traffic on the various communication links to be determined and the maximum bandwidth allocated to each input port of each switch to be configured accordingly.