A method and device for switching without disturbance of a redundant flight control module of a drone

Abstract

The application provides a method and device for switching over a redundant flight control module of a UAV, wherein the device sends PWM wave signals of a preset frequency to each other by the first flight control module and the second flight control module to monitor the state of the other, and sets the other flight control module as the main control module when one of the flight control modules fails; since the data is always bidirectional transmission between the first flight control module and the second flight control module, the first flight control module can receive the flight data transmitted by the second flight control module for synchronization at the first time after the first flight control module fails and then restores the main control function, so that the switching over of the UAV flight control is realized without disturbance.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of unmanned aerial vehicle flight control, and in particular to a method and device for non-interference switching of redundant flight control modules of an unmanned aerial vehicle. BACKGROUND

[0002] An unmanned aerial vehicle, referred to as a "drone", is a pilotless aircraft that is controlled by radio control equipment or a self-programmed control device. With the development of technology, drone technology is becoming increasingly mature. Drones are widely used due to their fast speed, flexible operation, wide range of uses, low cost, and good maneuverability. They not only play an extremely important role in modern warfare, but also have broad prospects in the civil field.

[0003] The flight control module of a drone is the core of the drone. For a drone using a single flight control module, if the flight control module malfunctions during flight, the flight control of the drone will malfunction, which will cause the drone to crash due to loss of control, resulting in unnecessary economic losses and safety hazards.

[0004] In order to improve the availability and stability of the flight control system of a drone, an application number "201610969778.2" discloses a flight control method and system for a drone. The system redundantly provides at least two flight controllers. The method comprises: obtaining device configuration information of each flight controller; determining whether the current flight controller is a master flight controller according to the device configuration information of each flight controller; if the current flight controller is the master flight controller, synchronously processing the flight state data and / or the task configuration data of the drone of the master flight controller; and publishing the synchronously processed data to each standby flight controller, so that each standby flight controller backs up the flight state data and / or the task configuration data of the drone. The present application redundantly provides flight controllers, which effectively improves the availability and stability of the flight control system of the drone.

[0005] However, the inventor has found that the master flight controller only synchronously processes flight data when it is in a normal working state. Once the master flight controller fails and is reset to a normal working state, it cannot receive any flight data, which results in the master flight controller being unable to effectively monitor the state of the drone when it resumes the master control function, and there is a certain safety hazard.

[0006] Therefore, after the master flight controller of the drone fails, it is necessary to achieve non-interference switching of the functions of each flight controller, which is a technical problem that needs to be solved by those skilled in the art. SUMMARY

[0007] The present application overcomes the defects in the prior art, and provides a method and device for switching a redundant flight control module of a UAV without disturbance.

[0008] To achieve the above object, the present application adopts the following technical solutions.

[0009] In a first aspect, the present application provides a method for switching a redundant flight control module of a UAV without disturbance, which is applied to a device for switching a redundant flight control module of a UAV without disturbance, the device comprising a first flight control module and a second flight control module.

[0010] The method comprises:

[0011] The first flight control module is set as a master control module, and the second flight control module is set as a slave control module, the first flight control module and the second flight control module send PWM wave signals of a preset frequency to each other to monitor the state of the other party, the master control module is configured to respond to the control command of the UAV, and the slave control module is configured not to respond to the control command of the UAV.

[0012] The first flight control module and the second flight control module respectively receive flight data of the UAV collected by a sensor, and respectively perform calculation based on the flight data to obtain a first calculation result and a second calculation result.

[0013] The first flight control module receives the second calculation result, and judges whether the received second calculation result is consistent with the first calculation result, and when the two are inconsistent, the second calculation result calculated by the second flight control module is synchronized as the first calculation result.

[0014] When the PWM wave signal received by the second flight control module is interrupted or the frequency is changed, the first flight control module is switched to the slave control module, the first flight control module is reset, and the second flight control module is switched to the master control module.

[0015] When the second flight control module receives the PWM wave signal emitted by the first flight control module again, the first flight control module is switched back to the master control module, and the second flight control module is switched back from the master control module.

[0016] As an optional embodiment, the apparatus further comprises a master-slave switching module, the master-slave switching module comprises a first pin and a second pin, and the method comprises:

[0017] The master-slave switching module realizes switching of the master control module or the slave control module by changing the level signals of the first pin and the second pin.

[0018] As an optional embodiment, the first flight control module comprises a first storage module, and the second flight control module comprises a second storage module.

[0019] The method comprises:

[0020] burning a control program into the first storage module;

[0021] After the UAV is started, the first flight control module acquires the control program in the first storage module and sends it to the second flight control module;

[0022] The second flight control module stores the received control program into the second storage module.

[0023] As an optional embodiment, the apparatus comprises a sensor for collecting the flight data, the sensor comprises an IMU and / or a GPS and / or an airspeed tube, and the flight data comprises UAV three-axis attitude angle and / or three-dimensional position information and / or airspeed.

[0024] As an optional embodiment, the first operation result or the second operation result comprises a roll angle, a pitch angle, a yaw angle, three-axis acceleration or three-axis angular velocity.

[0025] As an optional embodiment, the first flight control module and the second flight control module are respectively plug-removable arranged on the same circuit board, and the method comprises:

[0026] When one of the first flight control module or the second flight control module is removed from the circuit board, the first flight control module or the second flight control module still connected with the circuit board is automatically set as the master control module.

[0027] As an optional embodiment, the apparatus further comprises a ground control center, and the method comprises:

[0028] The ground control center sends a control command to the first flight control module or the second flight control module according to the physical address of the first flight control module or the second flight control module, so as to adjust one of the first flight control module or the second flight control module as the master control module and the other as the slave control module.

[0029] As an optional embodiment, the judging whether the received second operation result is consistent with the first operation result comprises: the master control module samples the second operation result calculated by the slave control module according to a predetermined sampling period frequency, and judges whether the received second operation result is consistent with the first operation result in the same sampling period.

[0030] And / or, the judging whether the PWM wave signal received by the second flight control module is interrupted or the frequency is changed comprises: judging whether the PWM wave signal received by the second flight control module is interrupted or the frequency is changed in the same sampling period.

[0031] As an optional embodiment, the device further comprises a signal shunt, and the method further comprises:

[0032] The signal shunt shunts the flight data collected by the sensor and transmits the flight data to the first flight control module and the second flight control module.

[0033] In a second aspect, the application further provides a non-interference switching device of a redundant flight control module of an unmanned aerial vehicle, characterized in that the device is used to execute the method steps of the first aspect of the application.

[0034] The application can achieve the following technical effects:

[0035] The application provides a non-interference switching method and device of a redundant flight control module of an unmanned aerial vehicle. The device is provided with a first flight control module and a second flight control module. The two modules monitor the state of each other by transmitting PWM wave signals of a preset frequency. When one of the flight control modules fails, the other flight control module is set as a master control module. Then, the failed flight control module is reset and restarted, and after the restart is completed, the failed flight control module is set as the master control module again. Since data is always transmitted bidirectionally between the first flight control module and the second flight control module, after the first flight control module recovers the master control function, the first flight control module can receive flight data transmitted by the second flight control module for synchronization at the first time, so that the loss of flight data can be effectively avoided, and non-interference switching of flight control of the unmanned aerial vehicle is realized. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 is a flowchart of a non-interference switching method of a redundant flight control module of an unmanned aerial vehicle according to an embodiment of the application;

[0037] Figure 2 is a flowchart of a non-interference switching method of a redundant flight control module of an unmanned aerial vehicle according to another embodiment of the application;

[0038] Figure 3 is a flowchart of a non-interference switching method of a redundant flight control module of an unmanned aerial vehicle according to still another embodiment of the application;

[0039] Figure 4 is a module schematic diagram of the uninterrupted switching device of the redundant flight control module of the unmanned aerial vehicle, which is related to another embodiment of the present application. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solutions and advantages of the present application more clear and understandable, the present application will be further described in detail below in combination with the drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not constitute a limitation on the present application.

[0041] Please refer to Figure 1 is a flow chart of the uninterrupted switching method of the redundant flight control module of the unmanned aerial vehicle, which is related to an embodiment of the present application. The method is applied to the uninterrupted switching device of the redundant flight control module of the unmanned aerial vehicle, and the device includes a first flight control module and a second flight control module.

[0042] The method includes the following steps:

[0043] Firstly, step S101 is entered to set the first flight control module as the master control module and the second flight control module as the slave control module. The first flight control module and the second flight control module send PWM wave signals of a preset frequency to each other to monitor the state of the other party.

[0044] Then, step S102 is entered. The first flight control module and the second flight control module respectively receive flight data of the unmanned aerial vehicle collected by a sensor, and respectively perform calculation based on the flight data to obtain a first calculation result and a second calculation result.

[0045] Then, step S103 is entered. The first flight control module receives the second calculation result, and judges whether the received second calculation result is consistent with the first calculation result. When the two are inconsistent, the second calculation result calculated by the second flight control module is synchronized as the first calculation result.

[0046] Then, step S104 is entered. When the PWM wave signal received by the second flight control module is interrupted or the frequency is changed, the first flight control module is switched as the slave control module, the first flight control module is reset, and the second flight control module is switched as the master control module.

[0047] Then, step S105 is entered. When the second flight control module receives the PWM wave signal of the preset frequency sent by the first flight control module again, the first flight control module is switched back to the master control module, and the second flight control module is switched back to the slave control module.

[0048] In the present embodiment, the master control module is configured to respond to the control command of the unmanned aerial vehicle, and the slave control module is configured not to respond to the control command of the unmanned aerial vehicle. The control command of the unmanned aerial vehicle can include attitude adjustment, data collection, start-stop control, etc.

[0049] In the embodiment, the first flight control module and the second flight control module can be implemented by a flight controller, and the predetermined frequency of the PWM wave signals transmitted by the first flight control module and the second flight control module to each other can be set according to actual needs. Preferably, the first flight control module and the second flight control module transmit the PWM wave signals of the predetermined frequency by using a UART communication protocol. The interruption or frequency change of the PWM wave signal received by the second flight control module indicates that the first flight control module currently has a fault, and the cause of the fault can be power failure, program runaway, line fault, crystal oscillator fault, etc.

[0050] In the embodiment, the device comprises sensors for collecting flight data, and the sensors comprise an IMU and / or a GPS and / or an airspeed tube. The flight data comprises three-axis attitude angles and / or three-dimensional position information and / or airspeed of the UAV. Preferably, the first calculation result or the second calculation result comprises a roll angle, a pitch angle, a yaw angle, three-axis acceleration or three-axis angular velocity. After the data collected by the sensors is obtained, the first flight control module or the second flight control module calculates the roll angle, the pitch angle, the yaw angle, the three-axis acceleration and the three-axis angular velocity by using an extended Kalman filter. In the embodiment, the first flight control module and the second flight control module transmit intermediate variables of attitude calculation and state estimation by using a SPI communication protocol.

[0051] Preferably, the step of judging whether the received second calculation result is consistent with the first calculation result comprises: the first flight control module samples the second calculation result calculated by the second flight control module according to a predetermined sampling period frequency, and judges whether the second calculation result received in the same sampling period is consistent with the first calculation result. The first flight control module and the second flight control module can ensure real-time synchronization of the flight data by continuously sampling the flight data of each other, and when the first flight control module is reset and restarted after a fault, the second flight control module as the slave control module at this time can share the current flight data of the second flight control module to the first flight control module at the first time, effectively avoiding loss of data and ensuring undisturbed switching of the control modules of the UAV.

[0052] In some embodiments, the device further comprises a master-slave switching module, and the master-slave switching module comprises a first pin and a second pin. The method comprises: the master-slave switching module changes the level signals of the first pin and the second pin to switch the first flight control module or the second flight control module. Preferably, the step of judging whether the PWM wave signal received by the second flight control module is interrupted or the frequency of the PWM wave signal received by the second flight control module changes comprises: judging whether the PWM wave signal received by the second flight control module is interrupted or the frequency of the PWM wave signal received by the second flight control module changes in the same sampling period. In this way, when the PWM wave signal is interrupted or the frequency of the PWM wave signal changes, the master-slave switching module can timely switch the first flight control module currently having a fault to the slave control module, and switch the second flight control module currently in a normal working state to the master control module, so as to ensure normal control of the UAV.

[0053] For example, the master-slave switching module has pins A and B. When pin A is high and pin B is low, the master-slave switching module receives input via pin IN1, and control commands for the drone's actuators (such as servos) are issued by the first flight control module. When pin A is low and pin B is high, the master-slave switching module receives input via pin IN2, and control commands for the drone's actuators (such as servos) are issued by the second flight control module. Within a sampling period, the frequency of the PWM wave signal received by the slave control module from the master control module changes, so that AB = 10 (pin A high, pin B low) becomes AB = 01 (pin A low, pin B high). Pin A is controlled by the master control module, and pin B by the slave control module. If a flight control module experiences an abnormality, the pin will be low.

[0054] In some embodiments, the first flight control module includes a first storage module, and the second flight control module includes a second storage module. Figure 2 As shown, the method includes: first, step S201, where the control program is burned into the first storage module; then, step S202, after the drone is started, the first flight control module retrieves the control program from the first storage module and sends it to the second flight control module; then, step S203, the second flight control module stores the received control program in the second storage module. This allows the control program to be burned only once, and other burned-in control programs can be retrieved and stored via communication. This ensures that any flight control module, when designated as the master control module, can promptly access the control program in its own storage module to control the drone's flight parameters.

[0055] In certain embodiments, the first flight control module and the second flight control module are respectively pluggable and arranged on the same circuit board, and the method includes: when one of the first flight control module or the second flight control module is removed from the circuit board, the first flight control module or the second flight control module that is still connected to the circuit board is automatically set as the main control module. In this way, when either the first flight control module or the second flight control module is removed from the circuit board, the device can enter a single flight control mode, that is, the remaining flight control module that is still connected to the circuit board is set as the main control module to control the flight status of the drone. In addition, the first flight control module and the second flight control module are set on the circuit board in a pluggable manner. When either flight control module is damaged, it can be replaced in time, thereby reducing the maintenance cost of the equipment.

[0056] In some embodiments, the device further comprises a ground control center, and the method further comprises: the ground control center sending a control command to the first flight control module or the second flight control module according to the physical address of the first flight control module or the second flight control module, so as to adjust one of the first flight control module or the second flight control module as a master control module and the other as a slave control module. In short, in addition to automatically switching when the first flight control module fails, the master-slave control module can also be switched by sending a switching control command by the ground control center, thereby further increasing the operability of the redundant flight control module of the unmanned aerial vehicle.

[0057] In some embodiments, the device further comprises a signal splitter, and the method further comprises: the signal splitter splitting and transmitting the flight data collected by the sensor to the first flight control module and the second flight control module. By setting the signal splitter to split the flight data signal collected by the sensor, the first flight control module and the second flight control module can receive completely consistent flight data signals in real time, which facilitates subsequent calculation of intermediate variables.

[0058] As shown in Figure 4 , in a second aspect, the present application also provides a non-interference switching device for a redundant flight control module of an unmanned aerial vehicle, which is used to execute the method steps of the first aspect of the present application.

[0059] In Figure 4 , the device comprises two redundant flight control modules, namely flight control module A (i.e. the first flight control module mentioned above) and flight control module B (i.e. the second flight control module mentioned above). Taking the flight control module A on one side as an example, there are six signal ports A1, A2, A3, A4, A5, A6, wherein A1, A2, A3, A4, A5 are connected with the flight control module B, A6 is connected with a two-way selection module (i.e. the master-slave switching module mentioned above), the two-way selection module comprises four signal input ports (IN1, IN2, A, B) and one output port; a one-to-two module (i.e. the signal splitter mentioned above) comprises one input port IN and two output ports Q1, Q2.

[0060] The functions of each signal port are as follows:

[0061] A1 signal port: output a fixed frequency PWM wave signal under the control of the flight control module A, so that the flight control module B can monitor the state of the flight control module A in real time;

[0062] A2 signal port: input a fixed frequency PWM wave signal output from the flight control module B to monitor the state of the flight control module B;

[0063] A3 signal port: a bidirectional port, after power on, the program in flight control module A is synchronized to flight control module B, in the process of unmanned aerial vehicle flight, when the intermediate variables generated by logical operation of master control module and slave control module are inconsistent, the master control module outputs the value of intermediate variable generated by logical operation to replace the value of intermediate variable generated by slave control module through this port;

[0064] A4 signal port: output intermediate variable generated by internal logical operation of flight control module A;

[0065] A5 signal port: input intermediate variable generated by internal logical operation of flight control module B;

[0066] A6 signal port: when flight control module A is master control module, output "high level", when flight control module A is slave control module or appears fault, output "low level", signal input selection IN1;

[0067] Two-way module: when A port input is high level and B port input is low level, select IN1 port as input; when A port input is low level and B port input is high level, select IN2 port as input;

[0068] One-to-two module: input data from IN port, divide data into two parts and output to flight control module A and flight control module B through Q1 and Q2 ports respectively;

[0069] In single flight control mode (i.e. only one flight control module is needed), A1, A2, A3, A4 and A5 ports stop working, and A6 port is high level (if flight control module A is reserved). As shown in FIG. 1, in single flight control mode, flight control module A is master control module, flight control module B is slave control module, and A1, A2, A3, A4 and A5 ports stop working. Figure 3 Figure 4 ​The working flow chart of the corresponding device. After the system is powered on, the default setting is that the flight control module A is the main control module and the flight control module B is the slave control module. The flight control program only needs to be downloaded and installed in the flight control module A, and the flight control module B will automatically synchronize the program in the flight control module A. The main control module and the slave control module simultaneously collect data from the sensor, and the driving rudder and pitch-rolling control module only receives control instructions from the main control module. The main control module and the slave control module send each other fixed-frequency PWM wave signals to monitor the state of the other party, and compare and synchronize the attitude solution and state estimation data (i.e. the first and second calculation results mentioned above) through high-speed serial communication, so as to ensure that the main control module and the slave control module have the same calculation results at all times. When the main control module fails, the slave control module will not receive the PWM wave signal from the main control module or receive an incorrect PWM wave signal, and the slave control module will switch to the main control module, and the original main control module will reset after hardware self-checking and switch to the slave control module. The driving rudder and pitch-rolling control module will not receive instructions from the original main control module, thereby realizing the redundant switching of the flight control. After the original main control module recovers, i.e. the current slave control module is switched to the main control module, the main control module receives the PWM wave signal of the current slave control module (i.e. the original slave control module) to realize state monitoring, and synchronizes the data of the slave control module at the same time, so as to ensure that the main control module and the slave control module can always realize non-disturbance switching.

[0070] In addition, in the present application, since the data collected by the main control module and the slave control module comes from the same sensor and is divided into two parts, and the comparison and synchronization of the periodic attitude solution and state estimation data are performed, the main control module and the slave control module can always maintain the same pace, so that after the main and slave switching, the input and output of the original slave control module will not be different, thereby ensuring the non-disturbance output of the entire redundant flight control system, and realizing the non-disturbance switching of the main and slave flight controls.

[0071] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any suitable manner in any one or more embodiments or examples. In addition, the different embodiments or examples described in the present specification and the features of the different embodiments or examples can be combined and combined by those skilled in the art without contradiction.

[0072] Although the embodiments of the present application have been shown and described above, it is understood that the above-described embodiments are exemplary and are not to be construed as limiting the present application, and that those ordinarily skilled in the art can make various changes, modifications, substitutions and variations within the scope of the present application.

[0073] The above detailed description of the application is not to be construed as limiting the scope of the application. Any other corresponding changes and modifications of the above-described embodiments according to the technical concept of the present application are to be included within the scope of the present application.

Claims

1. A method for non-disruptive switching of redundant flight control modules of an unmanned aerial vehicle, characterized in that: The method is applied to a disturbance-free switching device for redundant flight control modules of a UAV, the device comprising a first flight control module and a second flight control module; The method comprises: The first flight control module is set as a master control module, and the second flight control module is set as a slave control module. The first flight control module and the second flight control module send PWM wave signals of a preset frequency to each other to monitor each other's status; the master control module is configured to respond to control commands of the drone, and the slave control module is configured not to respond to control commands of the drone; The first flight control module and the second flight control module respectively receive flight data of the UAV collected by the sensor, and respectively perform calculations based on the flight data to obtain a first calculation result and a second calculation result; The first flight control module receives the second calculation result, determines whether the received second calculation result is consistent with the first calculation result, and synchronizes the second calculation result calculated by the second flight control module with the first calculation result if the two are inconsistent; When the PWM wave signal received by the second flight control module is interrupted or the frequency changes, the first flight control module is switched to a slave control module, the first flight control module is reset, and the second flight control module is switched to a master control module; When the second flight control module receives the PWM wave signal of the preset frequency sent by the first flight control module again, the first flight control module is switched back to the main control module, and the second flight control module is switched back to the slave control module; The device further includes a master-slave switching module, the master-slave switching module includes a first pin and a second pin, and the method includes: The master-slave switching module realizes the switching of the master control module or the slave control module by changing the level signals of the first pin and the second pin; wherein: The first pin is controlled by the master control module, and the second pin is controlled by the slave control module; When the first pin is at a high level and the second pin is at a low level, the master-slave switching module is input through the first pin, and the control command of the drone is issued through the first flight control module; When the first pin is at a low level and the second pin is at a high level, the master-slave switching module is input through the second pin, and the control command of the drone is issued through the second flight control module; The flight control module is abnormal and the corresponding connected pin becomes low level; The device further includes a signal splitter, and the method further includes: The signal splitter splits the flight data collected by the sensor and transmits the split data to the first flight control module and the second flight control module.

2. The method for non-disruptive switching of redundant flight control modules of a UAV according to claim 1, wherein: The first flight control module includes a first storage module, and the second flight control module includes a second storage module; The method comprises: Burning the control program into the first storage module; After the UAV is started, the first flight control module obtains the control program in the first storage module and sends it to the second flight control module; The second flight control module stores the received control program in the second storage module.

3. The method for non-disruptive switching of redundant flight control modules of a UAV according to claim 1, wherein: The device includes a sensor for collecting the flight data, wherein the sensor includes an IMU and / or a GPS and / or a pitot tube, and the flight data includes the three-axis attitude angle and / or three-dimensional position information and / or airspeed of the drone.

4. The method for non-disruptive switching of redundant flight control modules of a UAV according to claim 1 or 3, wherein: The first calculation result or the second calculation result includes a roll angle, a pitch angle, a yaw angle, a three-axis acceleration, or a three-axis angular velocity.

5. The method for non-disruptive switching of redundant flight control modules of a UAV according to claim 1, wherein: The first flight control module and the second flight control module are respectively pluggable and arranged on the same circuit board, and the method includes: When one of the first flight control module or the second flight control module is removed from the circuit board, the first flight control module or the second flight control module that is still connected to the circuit board is automatically set as the main control module.

6. The method for non-disruptive switching of redundant flight control modules of a UAV according to claim 1, wherein: The apparatus further includes a ground control center, and the method includes: The ground control center sends a control command to the first flight control module or the second flight control module according to the physical address of the first flight control module or the second flight control module to adjust one of the first flight control module or the second flight control module to a master control module and the other to a slave control module.

7. The method for non-disruptive switching of redundant flight control modules of a UAV according to claim 1, wherein: Determining whether the received second operation result is consistent with the first operation result includes: the main control module sampling the second operation result calculated by the slave control module according to a predetermined sampling period frequency, and determining whether the second operation result received within the same sampling period is consistent with the first operation result; And / or, determining whether the PWM wave signal received by the second flight control module is interrupted or the frequency changes includes: determining whether the PWM wave signal received by the second flight control module is interrupted or the frequency changes within the same sampling period.

8. A disturbance-free switching device for redundant flight control modules of unmanned aerial vehicles, characterized in that: The device is used to perform the method steps according to any one of claims 1 to 7.

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