Fault safety detection method applied to unmanned aerial vehicle

Abstract

The invention provides a fault safety detection method applied to an unmanned aerial vehicle, and the method comprises the steps: S1, setting any motor controller as a host, setting the other motor controller as a slave, and presetting a set of landing control instructions in the host; s2, detecting whether the unmanned aerial vehicle has stability fluctuation or communication delay in the control flight process of the flight control, and if not, returning to the step S2; if yes, turning to the step S3; s3, continuously resetting the communication between the flight controller and the two motor controllers, starting the communication between the two motor controllers, and reading a control instruction which is stored by the host and is issued by the flight controller for the last time; s4, judging whether the control instruction represents landing or not: if yes, driving the host to control the slave to cooperate according to the landing control instruction so as to enable the unmanned aerial vehicle to land; and if not, driving the host to control the unmanned aerial vehicle to hover. The method has the beneficial effects of improving the flight stability of the unmanned aerial vehicle in fault, improving the communication reliability and reducing the potential safety hazard.

Description

Technical Field

[0001] The present invention relates to the technical field of unmanned aerial vehicles, and in particular to a fault safety detection method applied to unmanned aerial vehicles. Background Art

[0002] With the development of science and technology, drones are used more and more widely in various fields, such as military, agriculture, environmental protection, logistics, etc. The flight control system and power system of drones are their core parts. Among them, the motor controller is an important part of the power system. It controls the speed of the motor by receiving instructions from the flight control, thereby controlling the flight status of the drone.

[0003] The communication quality between the flight control and the motor controller directly affects the flight safety of the UAV. At present, most UAVs use the CAN (Controller Area Network) bus for communication, which has the advantages of high speed, good real-time performance and high reliability.

[0004] The solution of the prior art is: when a CAN communication failure occurs in the motor controller of the remote control system and the power system of the drone, it is usually solved by restarting the CAN communication or using an external device in the form of a safety guard. However, the prior art still has some problems when dealing with CAN communication failures of drones: first, restarting CAN communication or using a safety guard may cause unstable flight status when communication fails, and may even cause the drone to crash; second, although the use of a safety guard can improve the reliability of drone flight, this will increase the manufacturing cost and maintenance cost of the drone; finally, the prior art often takes a long time to deal with CAN communication failures, which may cause the drone to be out of control during the failure, increasing the safety risks of the drone. Summary of the invention

[0005] The technical problem to be solved by the present invention is to improve the flight stability of the UAV when a fault occurs, improve communication reliability, and reduce safety hazards. In order to overcome the defects of the above-mentioned prior art (or related technology), the present invention provides a fault safety detection method applied to a UAV.

[0006] The present invention provides a fault safety detection method applied to an unmanned aerial vehicle, wherein a flight control of the unmanned aerial vehicle is preliminarily connected to two motor controllers of a biplane propeller, and a communication connection is established between the two motor controllers. The fault safety protection method comprises the following steps: Step S1, setting any one of the motor controllers as a master, setting another motor controller as a slave, and presetting a set of landing control instructions in the master; Step S2, detecting whether the UAV has stability fluctuation or communication delay during the flight control of the flight controller: If not, return to step S2; If yes, go to step S3; Step S3, continuously resetting the communication between the flight controller and the two motor controllers, and starting the communication between the two motor controllers, and reading the control instruction last issued by the flight controller stored in the host; Step S4, determining whether the control instruction represents landing: If yes, the host is driven to control the slaves to cooperate with each other according to the landing control instruction to land the UAV; If not, the host is driven to control the drone to hover.

[0007] Compared with the prior art, the present invention has the following advantages: In the present application, the two motor controllers are respectively set as the host and the slave. When it is determined in step S2 that there is a communication failure, the communication between the host and the slave is started, so that even if the communication between the flight control and the two motor controllers is disconnected, the communication reliability between the host and the slave can be guaranteed; by reading the control instruction issued by the flight control for the last time, it is determined whether to enable the landing control instruction pre-configured in the host, and the landing operation or the hovering operation is selected to ensure the flight stability of the UAV and avoid the crash of the UAV. At the same time, the CAN communication failure of the UAV is handled in a short time to avoid the UAV being out of control during the failure, thereby reducing the safety risks of the UAV.

[0008] In a possible implementation manner, a CAN communication bus is used to establish a communication connection between the flight control and the two motor controllers, and a 485 bus is used to establish a communication connection between the two motor controllers.

[0009] In a possible implementation manner, the transmission rate of the CAN communication bus is 5 KB / s and the maximum transmission distance is 10 km.

[0010] In a possible implementation manner, in step S1, the preset instruction content of the landing control instruction is: The motor speed of the biplane propeller is controlled to be reduced, the motor output power is gradually reduced to reduce the height of the UAV, and the direction of the biplane propeller is changed to land the UAV.

[0011] In a possible implementation, the stability fluctuation in step S2 includes a bit error, a fill error, a CRC check error, a format error, and an ACK error. In step S2, if the presence of the bit error, the fill error, the CRC check error, the format error, or the ACK error is detected, it is determined that there is a stability fluctuation; if the absence of the bit error, the fill error, the CRC check error, the format error, and the ACK error is detected, it is determined that there is no stability fluctuation.

[0012] In a possible implementation, in step S2, it is determined whether the response field during communication between the flight control and the two motor controllers is a dominant bit and the response delimiter is a recessive bit: If so, it is determined that there is no communication delay; If not, it is determined that there is a communication delay.

[0013] In a possible implementation manner, in step S3, continuously resetting the communication between the flight controller and the two motor controllers includes: Determine whether the communication between the flight control and the two motor controllers is restored after 10 consecutive resets: If not, initiating communication between the two motor controllers; If yes, exit.

[0014] In a possible implementation manner, in step S3, after initiating communication between the two motor controllers, the step further includes: Determine whether the communication between the flight controller and the two motor controllers is restored after a preset time interval: If yes, exit; If not, the host is driven to control the slaves to cooperate with each other according to the landing control instruction to land the UAV. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a flow chart of the steps of the present invention; Figure 2 It is a schematic diagram of the communication connection between the flight control and two motor controllers of the present invention. DETAILED DESCRIPTION

[0016] First, those skilled in the art should understand that these implementations are only used to explain the technical principles of the embodiments of the present application, and are not intended to limit the protection scope of the embodiments of the present application. Those skilled in the art can make adjustments to them as needed to adapt to specific application scenarios.

[0017] The present application is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] See also Figure 1 , the embodiment of the present application discloses a fault safety detection method applied to a drone, comprising: Step S1, setting any one of the motor controllers as a master, setting the other motor controller as a slave, and presetting a set of landing control instructions in the master; Step S2, detecting whether there is stability fluctuation or communication delay in the UAV during the flight control process of the flight controller: If not, return to step S2; If yes, go to step S3; Step S3, continuously resetting the communication between the flight controller and the two motor controllers, starting the communication between the two motor controllers, and reading the control instruction last issued by the flight controller stored in the host; Step S4, judging whether the control instruction represents landing: If so, the driving host controls the slaves to cooperate with each other to land the UAV according to the landing control command; If not, the host is driven to control the drone to hover.

[0019] See also Figure 2 In this application, the flight control of the drone is pre-connected with the two motor controllers of the biplane propeller, and a communication connection is established between the two motor controllers. The flight control is connected to the two motor controllers using a CAN communication bus, and the two motor controllers are connected to each other using a 485 bus.

[0020] Continue to see Figure 1Compared with the prior art, the present application mainly solves the following problems: 1) How to ensure the flight stability of the drone and avoid the crash of the drone when the motor controller in the remote control system and power system of the drone has a CAN communication failure; 2) How to improve the reliability of drone communication without increasing the manufacturing cost and maintenance cost of the drone; 3) How to deal with the CAN communication failure of the drone in a short time, avoid the drone being out of control during the failure, and reduce the safety hazards of the drone. In order to achieve the above purposes, the present application mainly adopts the following technical means: 1. Use the CAN communication bus method to realize the communication between the flight control and the motor controller of the biplane propeller. This method can update and store each instruction of the flight control in real time, and judge whether the connection of the CAN bus is normal, so as to ensure the flight stability of the drone; 2. When it is judged that a communication failure occurs, the CAN communication is continuously reset, and the last flight control instruction is read, and the 485 bus is used to transmit the instruction between the two motor controllers to ensure the stability of the drone, and start timing. If the CAN communication has not been successfully connected after a certain preset time interval, the preset landing control instruction is used to make the drone land safely; 3. The 485 bus is designed in hardware using MODbus Communication protocol, connecting the two motor controllers so that one of the two motor controllers is the host and the other is the slave. Assuming that the left motor controller is the host, a set of landing control instructions is preset in the host. For example, by controlling to reduce the motor speed and slowly reduce the output power of the motor, the height of the UAV is lowered, the direction of the biplane propeller is changed to make the UAV land safely, and the control instructions are sent to the slave to achieve a state of coordinated control between the two. The above three steps constitute the core technical means of the present application. Through these technical means, when a CAN communication failure occurs in the motor controller in the remote control system and power system of the UAV, the flight stability of the UAV can be guaranteed to avoid the crash of the UAV. At the same time, without increasing the manufacturing cost and maintenance cost of the UAV, the reliability of the UAV communication is improved, and the CAN communication failure of the UAV is handled in a short time to avoid the UAV being out of control during the failure, thereby reducing the safety hazards of the UAV.

[0021] Continue to see Figure 1 In the Can protocol, there are generally more error frames. When an error occurs, a global notification will be sent, such as a bit error, a padding error, a CRC check error, a format error, and an ACK error. In step S2, if a bit error or a padding error or a CRC check error or a format error or an ACK error is detected, it is determined that there is a stability fluctuation; if it is detected that there is no bit error, padding error, CRC check error, format error, or ACK error, it is determined that there is no stability fluctuation.

[0022] Continue to see Figure 1, bus delay will cause the response to become slow or unable to respond, at this time the sending node will resend, the response has two key bits, namely the response field and the response delimiter; under normal circumstances, the sending node waits for the response, if the response field is detected to be dominant and the response delimiter is recessive, it means there is a response, and it will be sent normally; if there is a delay, the response field will shift to the right, causing the response field to be recessive, and the receiving node will send an error frame, a global notification, then in step S2, determine whether the response field is dominant and the response delimiter is recessive during communication between the flight control and the two motor controllers: if so, it is determined that there is no communication delay; if not, it is determined that there is a communication delay.

[0023] Continue to see Figure 1 When the backup bus transmission is performed in step S3, the timing starts. If the CAN communication is not successfully connected after the preset time interval, the preset landing control instruction is used to make the drone land safely; in this step, the preset time interval is set to 1 minute. If the CAN communication is still not successfully connected within 1 minute, the preset landing control instruction is automatically started.

[0024] In the description of the present application, the description with reference to the terms "one embodiment", "some embodiments", "in the present embodiment", "specific example", or "some examples" etc. means that the specific features, mechanisms, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, mechanisms, materials or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0025] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A fault safety detection method applied to an unmanned aerial vehicle, characterized in that: The flight control of the UAV is connected to the two motor controllers of the biplane propeller in advance, and the two motor controllers are connected to each other. The fault safety protection method includes the following steps: Step S1, setting any one of the motor controllers as a master, setting another motor controller as a slave, and presetting a set of landing control instructions in the master; Step S2, detecting whether the UAV has stability fluctuation or communication delay during the flight control of the flight controller: If not, return to step S2; If yes, go to step S3; Step S3, continuously resetting the communication between the flight controller and the two motor controllers, and starting the communication between the two motor controllers, and reading the control instruction last issued by the flight controller stored in the host; Step S4, determining whether the control instruction represents landing: If yes, the host is driven to control the slaves to cooperate with each other according to the landing control instruction to land the UAV; If not, the host is driven to control the drone to hover.

2. The fail-safe detection method according to claim 1, characterized in that: The flight control and the two motor controllers are connected by a CAN communication bus, and the two motor controllers are connected by a 485 bus.

3. The fail-safe detection method according to claim 2, characterized in that: The transmission rate of the CAN communication bus is 5KB / s and the maximum transmission distance is 10km.

4. The fail-safe detection method according to claim 1, characterized in that: In step S1, the preset landing control instruction has the following contents: The motor speed of the biplane propeller is controlled to be reduced, the motor output power is gradually reduced to reduce the height of the UAV, and the direction of the biplane propeller is changed to land the UAV.

5. The fail-safe detection method according to claim 1, characterized in that: The stability fluctuation in the step S2 includes bit error, fill error, CRC check error, format error, and ACK error. In the step S2, if the presence of the bit error or the fill error or the CRC check error or the format error or the ACK error is detected, it is determined that there is a stability fluctuation; if the absence of the bit error, the fill error, the CRC check error, the format error, and the ACK error is detected, it is determined that there is no stability fluctuation.

6. The fail-safe detection method according to claim 1, characterized in that: In step S2, it is determined whether the response field during communication between the flight control and the two motor controllers is a dominant bit and the response delimiter is a recessive bit: If so, it is determined that there is no communication delay; If not, it is determined that there is a communication delay.

7. The fail-safe detection method according to claim 1, characterized in that: In the step S3, when the communication between the flight controller and the two motor controllers is continuously reset, it includes: Determine whether the communication between the flight control and the two motor controllers is restored after 10 consecutive resets: If not, initiating communication between the two motor controllers; If yes, exit.

8. The fail-safe detection method according to claim 1, characterized in that: In the step S3, after starting the communication between the two motor controllers, the step further includes: Determine whether the communication between the flight controller and the two motor controllers is restored after a preset time interval: If yes, exit; If not, the host is driven to control the slaves to cooperate with each other according to the landing control instruction to land the UAV.

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