Distributed power unmanned aerial vehicle control system and control method

Abstract

The invention relates to a distributed power unmanned aerial vehicle control system and control method, belongs to the technical field of unmanned aerial vehicle flight control, and solves the problems of loud noise, limited computing power, limited peripheral interfaces and weak anti-interference ability in the prior art, the distributed power unmanned aerial vehicle control system comprises: a control module comprising a PS end and a PL end; the PL end comprises a data synthesis and instruction analysis module, an inertial navigation and GPS data acquisition module, a motor feedback signal acquisition module and a corresponding interface module, and has data acquisition, data communication and peripheral interface functions; the PS end comprises a dual-core structure and comprises a flight control algorithm module with a flight control function and a motor control algorithm module with an FOC vector control algorithm function; the maintenance test module, the remote control and telemetering module, the load system module, the combined inertial navigation module, the GPS module and the power system communicate with the control module.

Description

Technical Field

[0001] The present invention relates to the technical field of UAV flight control, and particularly to a distributed power UAV control system and a control method. Background Art

[0002] Distributed power UAVs, as the name implies, have multiple power systems distributed on the UAV body, replacing the traditional large-size engine power system. In recent years, distributed power technology has been widely studied, and many novel distributed power aircraft have been proposed one after another. More common ones include electric vertical takeoff and landing aircraft (eVTOL), tilt-rotor UAVs, etc. Distributed power UAVs have the advantages of simple structure, high safety, high efficiency of the power system, low noise pollution, etc., making them have a wide range of application prospects in the civil and military aviation fields.

[0003] In order to achieve better power effects, the distributed power system has more stringent requirements for the power system, requiring the power system to meet the needs of application scenarios such as low noise, high lift, low speed, emergency braking, and high-precision control. The traditional brushless ESC power system is difficult to meet the above requirements. It is very difficult to control the brushless ESC when the motor operates at low speed; ordinary ESCs can only control the motor speed and cannot feedback the position of the motor rotor, making it difficult to control the rotation accuracy of the motor. The ESC drives the motor with a square wave, resulting in relatively high noise.

[0004] Chinese Patent Application, Publication No. CN115167491A, Invention Title "UAV Control System and Method", discloses a UAV control system that drives and controls the rotors of the UAV by providing a preset ESC scheme and adjusts the control according to the flight environment and flight trajectory during flight. This method uses the ESC drive mode, and it is very difficult to control the motor when it operates at low speed. It cannot feedback the position of the motor rotor, has low precision control over the rotation of the motor, and has relatively high noise.

[0005] Therefore, there is a need in the art for an improved UAV distributed power control system, expecting to achieve precise control of the UAV power system efficiently and in real time. Summary of the Invention

[0006] In order to solve the above problems, the present invention provides a distributed power UAV control system and a control method.

[0007] According to an embodiment of the present invention, a distributed power UAV control system is provided, including:

[0008] A control module, which includes a PS end and a PL end;

[0009] The PL side includes a data integration and instruction parsing module, an inertial navigation and GPS data acquisition module, a motor feedback signal acquisition module, and corresponding interface modules, and has functions of data acquisition, data communication, and peripheral interfaces;

[0010] The PS side includes a dual-core structure, including a flight control algorithm module with flight control functions and a motor control algorithm module with FOC vector control algorithm functions; and

[0011] A maintenance test module, a remote control and telemetry module, a payload system module, an integrated inertial navigation module, a GPS module, and a power system that communicate with the control module;

[0012] Among them, the integrated inertial navigation module includes a three-axis accelerometer, a three-axis gyroscope, a three-axis magnetometer, and a barometric altimeter;

[0013] The power system includes multiple motors and corresponding motor driver boards, and the motor driver board includes a resolver chip, a current sensor, a voltage sensor, and an inverter circuit module.

[0014] Optionally, the data integration and instruction parsing module on the PL side of the control module communicates with the maintenance test module, the remote control and telemetry module, and the payload system module;

[0015] The inertial navigation and GPS data acquisition module on the PL side of the control module communicates with the integrated inertial navigation module and the GPS module;

[0016] The motor feedback signal acquisition module on the PL side of the control module communicates with the power system;

[0017] Between the PS side and the PL side of the control module, communication and data interaction are carried out through the AXI bus, the APB bus, and the APB to AXI conversion bridge module.

[0018] Optionally, the flight control algorithm module on the PS side includes an attitude solution and data fusion module, a position controller, an attitude controller, and a control allocator; the motor control algorithm module on the PS side includes multiple FOC vector control algorithm modules.

[0019] According to another embodiment of the present invention, a distributed power UAV control method is provided, including the following steps:

[0020] Step S1, provide a control module, which includes a PS side, a PL side and multiple interface modules. The PS side includes a flight control algorithm module and a motor control algorithm module. The PL side includes a data integration and instruction parsing module, an inertial navigation and GPS data acquisition module, and a motor feedback signal acquisition module; and a PC maintenance test module, a remote control and telemetry module, a payload system module, an integrated inertial navigation module, a GPS module and a power system that communicate with the control module. Among them, the data integration and instruction parsing module communicates with the PC maintenance test module, the remote control and telemetry module, and the payload system module; the inertial navigation and GPS data acquisition module communicates with the integrated inertial navigation module and the GPS module; the motor feedback signal acquisition module communicates with the power system;

[0021] Step S2, the PL side of the control module obtains the collected data from the devices communicating with the control module, processes it and transmits it to the PS side;

[0022] Step S3, the PS side of the control module receives the data from the PL side, obtains the given speed and given position of each motor of the power system through the flight control algorithm module, and based on this, the motor control algorithm module performs FOC vector control algorithm operations to obtain a PWM signal with a specific period and duty cycle, and outputs it to the motor feedback signal acquisition module on the PL side;

[0023] Step S4, the motor feedback signal acquisition module on the PL side receives the PWM signal from the PS side, processes it through the SVPWM modulation algorithm to obtain an SVPWM wave, and outputs it to each motor of the power system to control the motor;

[0024] Step S5, each motor adjusts its speed according to the input SVPWM wave to complete the flight control of the UAV.

[0025] Optionally, step S2 specifically includes the following steps:

[0026] Step S2.1, the data integration and instruction parsing module on the PL side of the control module receives the transmitted data from the PC maintenance test module, the remote control and telemetry module, and the payload system module. After data integration and parsing, it transmits the integrated data and instructions to the PS side. The integrated data and instructions include task coordinates, self-check instructions, position instructions and attitude instructions;

[0027] Step S2.2, the inertial navigation and GPS data acquisition module on the PL side of the control module collects data from the integrated inertial navigation module and the GPS module, and filters the collected data to obtain filtered inertial navigation data and GPS data and transmits them to the PS side. The data collected from the inertial navigation module includes the three-axis accelerometer, three-axis gyroscope, three-axis magnetometer and barometric altimeter of the inertial navigation module, and the collected inertial navigation data;

[0028] Step S2.3, the motor feedback signal acquisition module at the PL end of the control module acquires the information of each motor and transmits it to the PS end.

[0029] Optionally, the step S2.3 specifically includes the following steps:

[0030] Step S2.3.1, the motor feedback signal acquisition module at the PL end of the control module receives the data of three-phase current and motor speed from each motor, performs sliding average filtering on the received data, and transmits it to the PS end;

[0031] Step S2.3.2, the motor feedback signal acquisition module at the PL end of the control module receives the rotor position from each motor, uses the CORDIC algorithm to calculate the trigonometric function values corresponding to the current rotor position, and transmits them to the PS end.

[0032] Optionally, the step S3 specifically includes the following steps:

[0033] Step S3.1, the flight control algorithm module at the PS end of the control module performs attitude solution and data fusion on the filtered inertial navigation data received from the PL end to obtain the current position of the UAV. This attitude solution and data fusion include fusing the inertial navigation data collected by the three-axis accelerometer and three-axis gyroscope of the inertial navigation module to obtain the current pitch angle and roll angle of the UAV; fusing the inertial navigation data collected by the three-axis magnetometer and three-axis gyroscope of the inertial navigation module to obtain the current yaw angle of the UAV; and obtaining the current altitude of the UAV through the inertial navigation data collected by the barometric altimeter of the inertial navigation module; obtaining the current speed of the UAV through the inertial navigation data collected by the three-axis accelerometer; and obtaining the current angular velocity of the UAV through the inertial navigation data collected by the three-axis gyroscope;

[0034] Step S3.2, according to the instruction information received from the data synthesis and instruction parsing module at the PL end, the flight control algorithm module at the PS end uses a double-loop feedback control method for position control and attitude control to obtain the desired control quantity, and then processes it through the control allocator to obtain the given speed and given position of each motor, and sends them to the motor control algorithm module at the PS end;

[0035] Step S3.3, FOC vector control algorithm, the motor control algorithm module at the PS end receives the given speed and given position of each motor, performs closed-loop control operations for the speed outer loop and current inner loop according to the given parameters, and uses the trigonometric function values corresponding to the current rotor position obtained by parallel operation at the PL end in step S2 for the transformation calculation of the FOC vector control algorithm to obtain the PWM period and duty cycle, and outputs the PWM signal to the motor feedback signal acquisition module at the PL end.

[0036] Optionally, the step S3.2 specifically includes the following steps:

[0037] Step S3.2.1, position control processing. In the flight control algorithm module, the task coordinates in the received command information are used as the desired position. The position error is calculated by subtracting the current position feedback of the UAV from the desired position. After being processed by the position controller, the desired speed is obtained. The speed error is calculated by subtracting the current speed feedback of the UAV from the desired speed. After being processed by the speed controller, the desired attitude of the UAV is obtained, completing the double-loop position control. Among them, the current position feedback of the UAV is the current position of the UAV obtained in step S3.1; the current speed feedback of the UAV is the current speed of the UAV obtained through the triaxial accelerometer in step S3.1; the obtained desired attitude of the UAV includes the desired pitch angle, roll angle, and heading angle.

[0038] Step S3.2.2, attitude control processing. In the flight control algorithm module, the desired attitude of the UAV is used as the input of attitude control. This desired attitude includes the desired pitch angle, roll angle, and heading angle. The angle error is calculated by subtracting the current angle feedback of the UAV from it. After being processed by the angle controller, the desired angular velocity is obtained. Then, the angular velocity error is calculated by subtracting the current angular velocity feedback of the UAV from the desired angular velocity. After being processed by the angular velocity controller, the desired control quantity is obtained, completing the double-loop attitude control. Among them, the current angle feedback of the UAV is the current pitch angle, roll angle, and yaw angle of the UAV obtained in step S3.1; the current angular velocity feedback of the UAV is the current angular velocity of the UAV acquired through the triaxial gyroscope in step S3.1.

[0039] Step S3.2.3, the desired control quantity obtained by the control allocator of the flight control algorithm module is processed to obtain the given speed and given position of each motor, and is output to the motor control algorithm module at the PS end.

[0040] Optionally, step S3.3 specifically includes the following steps:

[0041] Step S3.3.1, speed outer loop control processing. In the motor control algorithm module at the PS end, the speed error is calculated by subtracting the current motor speed from the given motor speed. After being operated by the speed outer loop, the desired motor speed, that is, the corresponding desired current, is obtained. Among them, the current motor speed is the motor speed transmitted to the PS end after the moving average filtering processing obtained in step S2.3.

[0042] Step S3.3.2, current inner loop control processing. In the motor control algorithm module at the PS end, the three-phase current collected in step S2.3 is transformed to obtain the two-phase rotating Id current and Iq current.

[0043] Step S3.3.3: Calculate the Iq current error by subtracting the desired current from the Iq current. After the inner loop operation of the Iq current, the desired Iq, which is the desired torque, is obtained. Through transformation, the period and duty cycle of the PWM are calculated.

[0044] To overcome the deficiencies of the prior art, a distributed power UAV control system and control method provided according to an embodiment of the present invention first introduce the FOC (Field-Oriented Control) vector control algorithm into the UAV power system to replace the traditional electronic speed control technology. The FOC vector control algorithm is not limited by the rotational speed for motor control and can achieve precise control at any rotational speed; the FOC vector control algorithm can also control the smooth commutation of the motor when the motor is operating at high speed; the FOC vector control algorithm uses torque to control the motor, which can be applied not only to the UAV power system but also to the payload; the FOC vector control algorithm uses sine wave control, and the generated noise is much smaller than that of the electronic speed control.

[0045] A distributed power UAV control system is provided, and its overall system block diagram is as Figure 1 shown. Among them, the PS side performs flight control algorithms and FOC vector control algorithm operations, and the PL side mainly executes functions such as data acquisition, data communication, and peripheral interfaces. Data interaction between the PS and the PL mainly uses AXI buses, APB buses, etc. for communication.

[0046] Compared with the prior art, a distributed power UAV control system and control method provided by the present invention have at least the following beneficial effects:

[0047] (1) The power control system of the present invention is not limited by the rotational speed for motor control and can achieve precise control at any rotational speed; when the motor is operating at high speed, it can also control the smooth commutation of the motor; it uses torque to control the motor, which can be applied not only to the UAV power system but also to the payload; it uses sine wave control, and the generated noise is much smaller than that of the electronic speed control.

[0048] (2) The UAV flight control platform and power control system of the present invention can implement multi-threaded operation control algorithms, flexibly configure a large number of peripheral interfaces, and greatly improve data interaction and its anti-interference ability by exchanging data through internal resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required in the embodiments. By referring to the drawings, the features and advantages of the present invention can be more clearly understood. The drawings are schematic and should not be construed as imposing any limitations on the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0050] Figure 1 It is an overall framework diagram of a distributed power UAV control system provided according to an embodiment of the present invention.

[0051] Figure 2 It is a hardware design block diagram of a distributed power UAV control system provided according to an embodiment of the present invention.

[0052] Figure 3 It is a control principle framework diagram of a distributed power UAV control system provided according to an embodiment of the present invention.

[0053] Figure 4 It is a position control and attitude control schematic diagram of a distributed power UAV control system provided according to an embodiment of the present invention.

[0054] Figure 5 It is a FOC vector control schematic diagram of a distributed power UAV control system provided according to an embodiment of the present invention. Specific embodiments

[0055] In order to more clearly understand the above objects, features and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, without conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0056] In the following description, many specific details are set forth in order to fully understand the present invention, but the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited by the specific embodiments disclosed below.

[0057] The following provides a detailed description of a distributed power UAV control system and a control method according to an embodiment of the present invention with reference to the accompanying drawings.

[0058] As Figure 1 and 2 shown, a distributed power UAV control system provided according to an embodiment of the present invention includes: a control module, which includes a PS (Processing System) end and a PL (Programmable Logic) end; and a maintenance and test module, a remote control and telemetry module, a payload system module, an integrated inertial navigation module, a GPS module, and a power system.

[0059] In this embodiment, the remote control and telemetry module may include a wireless data receiver module (2.4G communication).

[0060] The maintenance test module may include an EEPROM module and a PC maintenance test module.

[0061] The combined inertial navigation module may include a three-axis accelerometer, a three-axis gyroscope, a three-axis magnetometer, a barometric altimeter, etc.

[0062] The power system may include multiple motors and corresponding motor driver boards. The motor driver board may include an RDC resolver chip, a current sensor, a voltage sensor, an inverter circuit module, etc.

[0063] Such as Figure 1 and Figure 3 As shown, the control module includes a PL side and a PS side. Among them, the PL side has functions such as data acquisition, data communication, and peripheral interfaces; the PS side includes a dual-core structure. The flight control algorithm module has a flight control function, performs flight control (flight control) algorithm operations, calculates the given motor speed or the given rotor position, so as to control the movement of the UAV. The motor control algorithm module has a function of controlling the motor algorithm, performs FOC vector control algorithm operations, based on the given speed or given position of the flight control algorithm module, performs speed outer loop and current inner loop closed-loop control operations according to the given parameters, and obtains a PWM signal with a specific period and duty cycle for controlling the rotation of the motor, thereby providing power for the UAV; data exchange between the flight control algorithm module and the motor control algorithm module is carried out through an inter-core interrupt; communication and data interaction between the PS side and the PL side are carried out through the AXI bus, the APB bus, and the APB-to-AXI conversion bridge module. Using the internal bus resources for data interaction greatly improves the data interaction rate and its anti-interference ability. The inter-core interrupt is a soft interrupt structure inside the dual-core structure of the PS side. When the flight control algorithm module or the motor control algorithm module finishes its operation, it will trigger the inter-core interrupt, enter the interrupt and carry out data interaction.

[0064] Continuing to refer to Figure 1 and Figure 3 , the PL side may include: a system synchronization control flow module, a data integration and instruction parsing module, an inertial navigation and GPS data acquisition module, a motor feedback signal acquisition module, and corresponding interface modules. Among them, the data integration and instruction parsing module can communicate with the PC maintenance test module, the remote control and telemetry module, and the payload system module; the inertial navigation and GPS data acquisition module can communicate with the combined inertial navigation module and the GPS module; the motor feedback signal acquisition module can communicate with the power system. In this embodiment, the power system may include multiple motors and corresponding motor driver boards. For example but not limited to, the power system may include 4 motors.

[0065] Such as Figure 2As shown, the interface module at the PL end of the control module may include: an Ethernet PHY interface for communicating with the PC maintenance test module to complete the hardware board maintenance test or online upgrade function; a UART0 interface for communicating with the wireless data receiver module through the UART protocol; a CAN bus interface for data transmission with the payload system module to achieve multi-payload functions; an SPI bus serial interface for communicating with the first off-chip ADC, receiving the inertial navigation data collected by the combined inertial navigation module through the first off-chip ADC, and transmitting it to the control module through the serial SPI bus; a UART1 interface for communicating with the GPS module and receiving the GPS position information through the GPS module; an SPI bus parallel interface for communicating with the RDC resolver chip to obtain the motor speed and rotor position from the RDC resolver chip; an I2S bus interface for communicating with the second off-chip ADC to collect the three-phase current, bus voltage, and bus current of each motor through the second off-chip ADC; an SVPWM interface including 6 IO ports, which can directly output the SVPWM wave to the inverter circuit module to control the rotation of the motor through the inverter circuit module; an I2C bus interface for communicating with the EEPROM module to complete the storage and reading of key data and fault words.

[0066] As Figure 3As shown, during operation, the data synthesis and instruction parsing module at the PL end of the control module receives the transmitted data from the PC maintenance test module, the remote control and telemetry module, and the load system module. After data synthesis and parsing, the synthesized data and instructions are transmitted to the PS end. The parsed instruction information also generates a system synchronization signal by the system synchronization control flow module. This synchronization signal uses the interrupt resources between the PS and PL. The PL end outputs a system synchronization pulse signal to trigger the interrupt source at the PS end, so that the flight control algorithm and multiple motor control algorithms at the PS end are synchronized with the operation at the PL end. The PL end periodically generates 5 pulses in sequence, respectively triggering the corresponding interrupts at the PS end to run the flight control algorithm and the motor control algorithm. The inertial navigation and GPS data acquisition module at the PL end collects the data of the combined inertial navigation module and the GPS module, and after filtering, transmits it to the PS end. The motor feedback signal acquisition module at the PL end collects information and controls the output of multiple motors, collects the three-phase current, speed, etc. of each motor, and after moving average filtering, transmits it to the PS end, and processes the PWM signal generated by the PS end to generate an SVPWM signal and outputs it to each motor. In the motor feedback signal acquisition module, after receiving the rotor position from the motor, in order to reduce the operation period of the FOC vector control algorithm, the CRODIC (Coordinate Rotation Digital Computer) algorithm is used to calculate the trigonometric function values corresponding to the current rotor position and provide them to the PS end for the FOC vector control algorithm calculation. The motor feedback signal acquisition module at the PL end receives the PWM signal from the PS end, and then outputs the SVPWM wave through the SVPWM modulation algorithm to the motor drive board to control the motor accordingly.

[0067] Continue to refer to Figure 3 , the PS end of the control module performs flight control algorithm operations and FOC vector control algorithm operations. The flight control algorithm module at the PS end may include: an attitude solution and data fusion module, a position controller, an attitude controller, and a control distributor. The motor control algorithm module at the PS end may include an FOC vector control algorithm module. The flight control algorithm module at the PS end performs flight control algorithm operations. First, through the attitude solution and data fusion module, the inertial navigation data received from the combined inertial navigation module (such as a three-axis accelerometer, a three-axis gyroscope, etc.) via the PL end is subjected to attitude solution and data fusion. Among them, the attitude solution can use the Euler angle method, and the data fusion can use the complementary filtering method. The pitch angle and roll angle are obtained by fusing the data collected by the three-axis accelerometer and the three-axis gyroscope, the yaw angle can be obtained by fusing the data collected by the three-axis magnetometer and the three-axis gyroscope, and the current altitude is obtained from the data collected by the barometric altimeter, so as to obtain the current position of the UAV, which is the x, y, and z axis coordinates.

[0068] Next, as Figure 4As shown, the flight control algorithm module on the PS side uses a dual-loop feedback control method for position control and attitude control through a position controller and an attitude controller. During the position control process, the flight control algorithm module receives the task coordinates (3-axis coordinates), which are the desired positions. The difference between the desired position and the current position feedback (i.e., the current position of the UAV obtained through fusion) is calculated to obtain the position error. After passing through the position controller (outer-loop PI, outer-loop proportional-integral controller), the desired speed is obtained. Then, the difference between the desired speed and the current speed feedback is calculated to obtain the speed error. After passing through the speed controller (inner-loop PID, inner-loop proportional-integral-derivative controller), the desired attitude is obtained, and the dual-loop position control is completed. During the attitude control process, the desired attitude output by the position control is used as the input of the attitude control, which can also be called the angle expectation (pitch angle, roll angle, and heading angle). The attitude control is similar to the position control, both are dual-loop controls. The position control is position-speed control, and the attitude control is angle-angular velocity control; after the series position-attitude control, the desired control quantity is output. This desired control quantity passes through the control distributor of the flight control algorithm module, and the given speeds and given positions of each motor are output to the motor control algorithm module on the PS side, and the motor control algorithm module performs FOC vector control algorithm calculation to obtain and output the period and duty ratio of the PWM, and finally outputs the SVPWM wave to each motor of the power system through the SVPWM interface of the motor feedback signal acquisition module.

[0069] According to another embodiment of the present invention, a distributed power UAV control method is provided, including the following steps.

[0070] Step S1: Provide a control module, which includes a PS side and a PL side. The PS side includes a flight control algorithm module and a motor control algorithm module. The PL side includes a data integration and command parsing module, an inertial navigation and GPS data acquisition module, a motor feedback signal acquisition module, and corresponding interface modules; and a PC maintenance test module, a remote control and telemetry module, a payload system module, an integrated inertial navigation module, a GPS module, and a power system that communicate with the control module; wherein, the data integration and command parsing module communicates with the PC maintenance test module, the remote control and telemetry module, and the payload system module; the inertial navigation and GPS data acquisition module communicates with the integrated inertial navigation module and the GPS module; the motor feedback signal acquisition module communicates with the power system.

[0071] Step S2: The PL side of the control module obtains the collected data from the devices communicating with the control module, processes it, and transmits it to the PS side. This step S2 specifically includes the following steps.

[0072] Step S2.1: The data synthesis and instruction parsing module on the PL side of the control module receives the transmitted data from the PC maintenance test module, the remote control and telemetry module, and the load system module. After data synthesis and parsing, the synthesized data and instructions are transmitted to the PS side. The PL side may also include a system synchronization control flow module. The parsed instruction information generates a system synchronization signal by this system synchronization control flow module, and the system synchronization signal triggers the interrupt source on the PS side, so that the PS side and the PL side run in synchronization. The synthesized data and instructions include maintenance self-check instructions, position instructions, attitude instructions, task coordinates (3-axis coordinates), etc.

[0073] Step S2.2: The inertial navigation and GPS data acquisition module on the PL side of the control module acquires data from the combined inertial navigation module and the GPS module, and performs filtering processing on the acquired data to obtain the filtered inertial navigation data and GPS data and transmits them to the PS side. The data acquired from the inertial navigation module includes the inertial navigation data acquired from the three-axis accelerometer, three-axis gyroscope, three-axis magnetometer, and barometric altimeter of the inertial navigation module.

[0074] Step S2.3: The motor feedback signal acquisition module on the PL side of the control module acquires the information of each motor and transmits it to the PS side. This step S2.3 specifically includes the following steps.

[0075] Step S2.3.1: The motor feedback signal acquisition module receives data such as three-phase current and motor speed from each motor, performs sliding average filtering processing on the received data, and transmits it to the PS side.

[0076] Step S2.3.2: The motor feedback signal acquisition module receives the rotor position from each motor, calculates the trigonometric function values corresponding to the current rotor position using the CRODIC algorithm, and transmits them to the PS side. The trigonometric function values corresponding to the current rotor position are used for the FOC vector control algorithm calculation on the PS side.

[0077] Step S3: The PS side of the control module receives data from the PL side, performs flight control algorithm operations through the flight control algorithm module to obtain the given speeds and given positions of the motors of the power system, and based on this, performs FOC vector control algorithm operations through the motor control algorithm module to obtain a PWM signal with a specific period and duty cycle, and outputs it to the motor feedback signal acquisition module on the PL side. This step S3 specifically includes the following steps.

[0078] Step S3.1: The flight control algorithm module at the PS end of the control module performs attitude solution and data fusion on the filtered inertial navigation data received from the PL end to obtain the current position of the UAV. This attitude solution and data fusion include fusing the inertial navigation data collected by the three-axis accelerometer and three-axis gyroscope of the inertial navigation module to obtain the current pitch angle and roll angle of the UAV; fusing the inertial navigation data collected by the three-axis magnetometer and three-axis gyroscope of the inertial navigation module to obtain the current yaw angle of the UAV; obtaining the current altitude of the UAV through the inertial navigation data collected by the barometric altimeter of the inertial navigation module; obtaining the current speed of the UAV through the inertial navigation data collected by the three-axis accelerometer; and obtaining the current angular velocity of the UAV through the inertial navigation data collected by the three-axis gyroscope. Among them, the attitude solution can adopt the Euler angle method, and the data fusion can adopt the complementary filtering method. The current position of the UAV obtained in this step is a three-axis coordinate.

[0079] Step S3.2: According to the instruction information received from the data synthesis and instruction parsing module at the PL end, the flight control algorithm module at the PS end uses the double-loop feedback control method for position control and attitude control to obtain the desired control quantity, and then processes it through the control distributor to obtain the given speed and given position of each motor, and sends them to the motor control algorithm module at the PS end. See Figure 4 , this step S3.2 specifically includes the following steps.

[0080] Step S3.2.1: Position control processing. The flight control algorithm module takes the task coordinates (3-axis coordinates) in the received instruction information as the desired position, calculates the position error by subtracting the current position feedback of the UAV from the desired position, processes it through the position controller (outer loop PI, outer loop proportional-integral controller) to obtain the desired speed, and then calculates the speed error by subtracting the current speed feedback of the UAV from the desired speed, and processes it through the speed controller (inner loop PID, inner loop proportional-integral-derivative controller) to obtain the desired attitude of the UAV, completing the double-loop position control. The current position feedback of this UAV is the current position of the UAV obtained in step S3.1. The current speed feedback of this UAV is the current speed of the UAV obtained through the three-axis accelerometer in step S3.1. The obtained desired attitude of the UAV can also be called the angle expectation, including the desired pitch angle, roll angle, and heading angle.

[0081] Step S3.2.2, attitude control processing. In the flight control algorithm module, the desired attitude of the UAV is used as the input of attitude control. The desired attitude includes the desired pitch angle, roll angle, and heading angle. The angle error is calculated by taking the difference between the desired attitude and the current angle feedback of the UAV. After being processed by the angle controller, the desired angular velocity is obtained. Then, the angular velocity error is calculated by taking the difference between the desired angular velocity and the current angular velocity feedback of the UAV. After being processed by the angular velocity controller, the desired control quantity is obtained, completing the double-loop attitude control. The current angle feedback of the UAV is the current pitch angle, roll angle, and yaw angle of the UAV obtained in Step S3.1. The current angular velocity feedback of the UAV is the current angular velocity of the UAV acquired by the three-axis gyroscope in Step S3.1.

[0082] Step S3.2.3, the control distributor in the flight control algorithm module processes the obtained desired control quantity to obtain the given rotational speed and given position (the given position is a reserved parameter) of each motor, and outputs them to the motor control algorithm module at the PS end.

[0083] Step S3.3, FOC vector control algorithm. The motor control algorithm module at the PS end receives the given rotational speed and given position of each motor, performs closed-loop control operations for the speed outer loop and current inner loop according to the given parameters, and uses the trigonometric function values corresponding to the current rotor position obtained by parallel operation in Step S2 at the PL end for Park and inverse Park transformation calculations in the FOC vector control algorithm to obtain the PWM period and duty cycle, and outputs the PWM signal to the motor feedback signal acquisition module at the PL end. This Step S3.3 specifically includes the following steps.

[0084] Step S3.3.1, speed outer loop control processing. In the motor control algorithm module at the PS end, the speed error is calculated by taking the difference between the given rotational speed of the motor and the current motor rotational speed. After being processed by the speed outer loop operation (PI), the desired rotational speed of the motor, that is, the corresponding desired current, is obtained. The current motor rotational speed is the motor rotational speed after sliding average filtering processing obtained in Step S2.3 and transmitted to the PS end.

[0085] Step S3.3.2, current inner loop control processing. In the motor control algorithm module at the PS end, the three-phase current collected in Step S2.3 is transformed through Clark and Park transformations to obtain two-phase rotating Id current (excitation current) and Iq current (torque current). By obtaining the trigonometric function values corresponding to the current rotor position through parallel operation at the PL end and providing them to the PS end for Park and inverse Park transformation calculations in the FOC vector control algorithm, the operation period of the FOC vector control algorithm running at the PL end can be reduced, greatly improving the operation efficiency of this distributed power UAV control system.

[0086] Step S3.3.3, as Figure 5As shown, the difference between the desired current and the Iq current is calculated to obtain the Iq current error. Through the inner loop operation of the Iq current, the desired Iq, that is, the desired torque, is obtained. To maximize the torque, the Id current is set to 0 mA. Through the inner loop operation of the Id current, the Id current is controlled to 0 mA, and the desired Id is output. The desired Id being 0 mA makes the Iq current maximum, that is, the torque reaches the maximum. Then, the obtained desired Iq and desired Id are subjected to the inverse Park transformation, and then the PWM period and duty cycle are calculated to obtain the PWM signal.

[0087] Step S4: The motor feedback signal acquisition module at the PL end receives the PWM signal from the PS end, processes it through the SVPWM modulation algorithm to obtain the SVPWM wave, and outputs it to each motor of the power system to control the motors. The motor feedback signal acquisition module can transmit the SVPWM wave to the motor drive board corresponding to each motor through the SVPWM interface.

[0088] Step S5: Each motor adjusts its speed according to the input SVPWM wave to complete the flight control of the UAV.

[0089] All of the above optional technical solutions can be combined arbitrarily to form the optional embodiments of the present application, which will not be elaborated here one by one.

[0090] It should be understood that the magnitudes of the sequence numbers of the steps in the above embodiments do not mean the order of execution. The order of execution of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present invention.

[0091] The above is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention.

Claims

1. A distributed power UAV control system, characterized in that, Comprising: A control module, which includes a PS side and a PL side; The PL side includes a data integration and instruction parsing module, an inertial navigation and GPS data acquisition module, a motor feedback signal acquisition module, and corresponding interface modules, and has functions of data acquisition, data communication, and peripheral interfaces; The PS side includes a dual-core structure, including a flight control algorithm module with flight control function and a motor control algorithm module with FOC vector control algorithm function; and A maintenance test module, a remote control and telemetry module, a payload system module, an integrated inertial navigation module, a GPS module, and a power system that communicate with the control module; Wherein, the integrated inertial navigation module includes a three-axis accelerometer, a three-axis gyroscope, a three-axis magnetometer, and a barometric altimeter; The power system includes multiple motors and corresponding motor drive boards, and the motor drive boards include resolver chips, current sensors, voltage sensors, and inverter circuit modules.

2. The distributed power UAV control system according to claim 1, characterized in that: The data integration and instruction parsing module of the PL side of the control module communicates with the maintenance test module, the remote control and telemetry module, and the payload system module; The inertial navigation and GPS data acquisition module of the PL side of the control module communicates with the integrated inertial navigation module and the GPS module; The motor feedback signal acquisition module of the PL side of the control module communicates with the power system; Between the PS side and the PL side of the control module, communication and data interaction are carried out through an AXI bus, an APB bus, and an APB to AXI conversion bridge module.

3. The distributed power UAV control system according to claim 1, characterized in that: The flight control algorithm module of the PS side includes an attitude solution and data fusion module, a position controller, an attitude controller, and a control allocator; The motor control algorithm module of the PS side includes multiple FOC vector control algorithm modules.

4. The control method of the distributed power UAV control system according to any one of claims 1 to 3, characterized in that, Comprising the following steps: Step S1, providing a control module, which includes a PS side, a PL side, and multiple interface modules. The PS side includes a flight control algorithm module and a motor control algorithm module, and the PL side includes a data integration and instruction parsing module, an inertial navigation and GPS data acquisition module, and a motor feedback signal acquisition module; And a PC maintenance test module, a remote control and telemetry module, a payload system module, an integrated inertial navigation module, a GPS module, and a power system that communicate with the control module; wherein, the data integration and instruction parsing module communicates with the PC maintenance test module, the remote control and telemetry module, and the payload system module; the inertial navigation and GPS data acquisition module communicates with the integrated inertial navigation module and the GPS module; the motor feedback signal acquisition module communicates with the power system; Step S2, the PL side of the control module obtains the acquired data from the devices communicating with the control module, processes it, and transmits it to the PS side; Step S3: The PS end of the control module receives data from the PL end, obtains the given rotational speeds and given positions of the motors of the power system through the flight control algorithm module, and based on this, performs FOC vector control algorithm operations through the motor control algorithm module to obtain a PWM signal with a specific period and duty cycle, and outputs it to the motor feedback signal acquisition module at the PL end; Step S4: The motor feedback signal acquisition module at the PL end receives the PWM signal from the PS end, processes it through the SVPWM modulation algorithm to obtain an SVPWM wave, and outputs it to each motor of the power system to control the motors; Step S5: Each motor adjusts its rotational speed according to the input SVPWM wave to complete the flight control of the UAV.

5. The control method according to claim 4, wherein The specific steps of step S2 are as follows: Step S2.1: The data integration and instruction parsing module at the PL end of the control module receives the transmitted data from the PC maintenance and test module, the remote control and telemetry module, and the payload system module. After data integration and parsing, the integrated data and instructions are transmitted to the PS end. The integrated data and instructions include task coordinates, self-check instructions, position instructions, and attitude instructions; Step S2.2: The inertial navigation and GPS data acquisition module at the PL end of the control module acquires data from the combined inertial navigation module and the GPS module, and performs filtering processing on the acquired data to obtain filtered inertial navigation data and GPS data and transmits them to the PS end. The data acquired from the inertial navigation module includes the inertial navigation data acquired by the three-axis accelerometer, three-axis gyroscope, three-axis magnetometer, and barometric altimeter of the inertial navigation module; Step S2.3: The motor feedback signal acquisition module at the PL end of the control module acquires the information of each motor and transmits it to the PS end.

6. The control method according to claim 5, wherein The specific steps of step S2.3 are as follows: Step S2.3.1: The motor feedback signal acquisition module at the PL end of the control module receives the data of the three-phase current and the motor rotational speed from each motor, performs moving average filtering processing on the received data, and transmits it to the PS end; Step S2.3.2: The motor feedback signal acquisition module at the PL end of the control module receives the rotor position from each motor, calculates the trigonometric function values corresponding to the current rotor position using the CORDIC algorithm, and transmits them to the PS end.

7. The control method according to claim 6, wherein The specific steps of step S3 are as follows: Step S3.1: The flight control algorithm module at the PS end of the control module performs attitude solution and data fusion on the filtered inertial navigation data received from the PL end to obtain the current position of the UAV. The attitude solution and data fusion include fusing the inertial navigation data acquired by the three-axis accelerometer and three-axis gyroscope of the inertial navigation module to obtain the current pitch angle and roll angle of the UAV; fusing the inertial navigation data acquired by the three-axis magnetometer and three-axis gyroscope of the inertial navigation module to obtain the current yaw angle of the UAV; and obtaining the current altitude of the UAV through the inertial navigation data acquired by the barometric altimeter of the inertial navigation module; obtaining the current speed of the UAV through the inertial navigation data acquired by the three-axis accelerometer; obtaining the current angular velocity of the UAV through the inertial navigation data acquired by the three-axis gyroscope; Step S3.2: According to the instruction information received from the data integration and instruction parsing module of the slave PL side, the flight control algorithm module on the PS side uses a double-loop feedback control method for position control and attitude control to obtain the desired control quantity. Then, through the processing of the control allocator, the given rotational speeds and given positions of each motor are obtained and sent to the motor control algorithm module on the PS side; Step S3.3: FOC vector control algorithm. The motor control algorithm module on the PS side receives the given rotational speeds and given positions of each motor, performs closed-loop control operations for the speed outer loop and current inner loop according to the given parameters, and uses the trigonometric function values corresponding to the current rotor position obtained by parallel operation in the PL side in step S2 for the transformation calculation of the FOC vector control algorithm to obtain the PWM period and duty cycle, and outputs this PWM signal to the motor feedback signal acquisition module on the PL side.

8. The control method according to claim 7, wherein The specific steps of step S3.2 are as follows: Step S3.2.1: Position control processing. The flight control algorithm module takes the task coordinates in the received instruction information as the desired position, calculates the position error by taking the difference between the desired position and the current position feedback of the UAV, and after being processed by the position controller, obtains the desired speed. Then, calculates the speed error by taking the difference between the desired speed and the current speed feedback of the UAV, and after being processed by the speed controller, obtains the desired attitude of the UAV, completing the double-loop position control; where the current position feedback of the UAV is the current position of the UAV obtained in step S3.1; the current speed feedback of the UAV is the current speed of the UAV obtained by the three-axis accelerometer in step S3.1; the obtained desired attitude of the UAV includes the desired pitch angle, roll angle, and yaw angle; Step S3.2.2: Attitude control processing. In the flight control algorithm module, the desired attitude of the UAV, which includes the desired pitch angle, roll angle, and yaw angle, is used as the input of the attitude control. Calculate the angle error by taking the difference between the desired attitude and the current angle feedback of the UAV, and after being processed by the angle controller, obtain the desired angular velocity. Then, calculate the angular velocity error by taking the difference between the desired angular velocity and the current angular velocity feedback of the UAV, and after being processed by the angular velocity controller, obtain the desired control quantity, completing the double-loop attitude control; where the current angle feedback of the UAV is the current pitch angle, roll angle, and yaw angle of the UAV obtained in step S3.1; the current angular velocity feedback of the UAV is the current angular velocity of the UAV collected by the three-axis gyroscope in step S3.1; Step S3.2.3: Process the desired control quantity obtained by the control allocator of the flight control algorithm module to obtain the given rotational speeds and given positions of each motor, and output them to the motor control algorithm module on the PS side.

9. The control method according to claim 8, wherein The specific steps of step S3.3 are as follows: Step S3.3.1: Speed outer loop control processing. In the motor control algorithm module on the PS side, calculate the speed error by taking the difference between the given rotational speed of the motor and the current motor rotational speed, and through the speed outer loop operation, obtain the desired rotational speed of the motor, which is the corresponding desired current. Where the current motor rotational speed is the motor rotational speed after the moving average filtering process obtained in step S2.3 and transmitted to the PS side; Step S3.3.2, current inner loop control processing. In the motor control algorithm module at the PS end, the three-phase current collected in Step S2.3 is transformed to obtain two-phase rotating Id current and Iq current. Step S3.3.3, subtract the desired current from the Iq current to calculate the Iq current error. After the Iq current inner loop operation, the desired Iq, that is, the desired torque, is obtained. Through transformation, the period and duty ratio of PWM are calculated.

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