CN205880667U - Fixed wing uavs automatic flight control system of two remaining sensors - Google Patents

Abstract

The utility model discloses a fixed wing uavs automatic flight control system of two remaining sensors adopts two remaining sensors, for the carry MTI of high accuracy and the board year combination sensor of low precision, the difference GPS of high accuracy and the barometer of low precision. The utility model discloses a two remaining sensors improve reliability and security that fixed wing uavs flew, ground satellite station and wireless data transmission module is added, the course line of automatic flight can be modifyd at any time, add the EEPROM module, can take notes boat point information and state of flight, be convenient for survey.

Description

An automatic flight control system for fixed-wing unmanned aerial vehicles with dual redundant sensors

technical field

The utility model relates to an automatic flight control system of a fixed-wing unmanned aerial vehicle with dual redundancy sensors, belonging to the technical field of control of the fixed-wing unmanned aerial vehicle.

Background technique

Small and medium-sized fixed-wing UAVs are currently widely used in land surveys and forest fire prevention. However, due to the difficulty of stable control of fixed-wings, it is necessary to design a flight control system that can fly autonomously.

At present, the attitude sensor and altitude sensor of fixed-wing UAVs mostly use a single module design. The attitude sensor and the altitude sensor are the core parts of the automatic flight of the UAV. If there is a problem with the two modules, the UAV will not be able to fly according to the established trajectory. Errors in the altitude information will cause errors in the altitude control and cause the UAV to stall. Reduced reliability and security.

Therefore, it is urgent to solve the above problems.

Utility model content

Aiming at the defects involved in the background technology, the utility model provides an automatic flight control system of a fixed-wing unmanned aerial vehicle with dual redundant sensors, which improves the reliability and safety of the unmanned aerial vehicle.

The utility model adopts the following technical solutions for solving the above-mentioned technical problems:

The utility model provides a fixed-wing unmanned aerial vehicle automatic flight control system with dual redundant sensors, which is characterized in that it includes an airborne part and a ground station part; the airborne part includes a fixed-wing unmanned aerial vehicle body, a flight mechanism, Flight control unit, remote control receiver, sensor module, wireless data transmission module, battery module; the flight mechanism includes an electronic governor, a motor, blades, steering gear, wherein the blades are installed on the motor; the motor is located on a fixed The front end of the wing UAV is connected to the flight control unit through the electronic governor; the steering gear is connected to the flight control unit through the PWM output drive circuit to control the elevator, aileron, and rudder; the sensor module includes MIT attitude sensor, six-degree-of-freedom attitude sensor, three-degree-of-freedom magnetic field sensor, barometer, differential GPS, and airspeed; Differential GPS, airspeed meter, remote controller receiver, wireless data transmission module, and battery module are connected; the ground station part includes a control module, a ground wireless data transmission module and a remote controller, wherein the ground wireless data transmission module and the airborne part Wireless data transmission module for wireless communication.

As a further optimization solution of the present invention, the motor is connected with the fixed-wing UAV through a linkage mechanism.

As a further optimization solution of the present invention, the MIT attitude sensor is mounted and connected to the flight control unit through UART.

As a further optimization solution of the present invention, the six-degree-of-freedom attitude sensor, the three-degree-of-freedom magnetic field sensor and the barometer are onboard and connected to the flight control unit through the I2C bus.

As a further optimization scheme of the utility model, the wireless data transmission module is connected with the flight control unit through the UART serial port, and the airspeed meter module is connected with the flight control unit through the I2C bus.

As a further optimization scheme of the utility model, it also includes an EEPROM module connected with the flight control unit through the I2C bus.

Compared with the prior art by adopting the above technical scheme, the utility model has the following technical effects:

(1) Adopt dual redundant sensors to improve the reliability and safety of fixed-wing UAV flight;

(2) By adding ground station and wireless data transmission module, the automatic flight route can be modified at any time;

(3) EEPROM module is added to record waypoint information and flight status, which is convenient for observation.

Description of drawings

Fig. 1 is a structural block diagram of the utility model.

detailed description

Below in conjunction with accompanying drawing, the technical scheme of the utility model is described in further detail:

The utility model discloses an automatic flight control system for a fixed-wing unmanned aerial vehicle with dual redundant sensors, which includes an airborne part and a ground station part; the airborne part includes a fixed-wing unmanned aerial vehicle body, a flight mechanism, a flight control unit, Remote control receiver, sensor module, wireless data transmission module, battery module; the flight mechanism includes an electronic governor, a motor, blades, and a steering gear, wherein the blades are installed on the motor; the motor is located on the fixed-wing UAV The front end of the nose is connected to the flight control unit through the electronic governor; the steering gear is used to control the elevator, aileron, and rudder, and is connected to the flight control unit through the PWM output driving circuit; the sensor module includes an MIT attitude sensor, a six-degree-of-freedom attitude sensor, three-degree-of-freedom magnetic field sensor, barometer, differential GPS, and airspeed; meter, remote controller receiver, wireless data transmission module, and battery module; the ground station part includes a control module, a ground wireless data transmission module and a remote controller, wherein the ground wireless data transmission module is connected to the airborne wireless data transmission module for wireless communication.

The utility model adopts a conventional fixed-wing unmanned aerial vehicle body structure, including an electronic governor, a motor, a blade, five steering gears, and the five steering gears are used to control two elevators, two ailerons, A rudder, connected with the flight control unit through the PWM output driving circuit. The flight trajectory and flight speed of the fixed-wing UAV are controlled by the motor, aileron, elevator, and rudder. The rotation of the motor provides the forward power of the UAV flight, and the ailerons, elevators, and rudders are used to control the height and heading of the UAV.

1. Hardware implementation and structural principle of the flight control system

As shown in Figure 1, the flight control system of the fixed-wing UAV includes an airborne part and a ground station control part. There are two ways of communication between the airborne part and the ground station, namely 2.4GHz FUTABA remote control wireless communication and 915MHz wireless transmission module communication. The FUTABA remote control is a general-purpose remote control for model aircraft produced by Futaba Electronics Industry Co., Ltd., which is used in conjunction with the receiver of this brand. The operator of the model airplane can generate remote control PWM signals for each channel with different pulse widths by turning some levers on the remote control. Different positions of each lever correspond to different strokes. The transmission frequency of the wireless data transmission module is 915MHz, and the maximum transmission distance is 700m. It is divided into two modules, namely the Air module (serial port) for the aircraft, and the Ground module (USB interface) for connecting to the computer on the ground.

The airborne part of the invention includes a flight control unit (CPU), a sensor module, a wireless data transmission module, a power supply module and a remote control receiver. The motor and steering gear are connected to the flight control unit (CPU) through the PWM output drive circuit; the six-degree-of-freedom attitude sensor, three-degree-of-freedom magnetic field sensor, barometer, EEPROM, and airspeed are connected to the flight control unit (CPU) through the I2C bus The wireless data transmission module is connected with the flight control unit (CPU) through the UART serial port; the MTI and differential GPS are connected with the flight control unit (CPU) through the USART serial port; The transmission module performs data communication; the remote control receiver is connected to the flight control unit (CPU) through the UART serial port (using the SBUS protocol); the power supply module is connected to the flight control unit through the AD interface.

(1) Flight control computer hardware design

The flight control unit of the present invention adopts a 32-bit floating-point single-chip microcomputer, and the controller is STM32F407.

The controller STM32F407 is a 32-bit MCU based on the 252MIPS Cortex-M4 architecture, with a clock frequency up to 168MHZ. It has rich hardware interface resources (4 USARTs, 2 USATs, 3 I2Cs, 3 SPIs, 3 12-bit ADs, 2 CAN, etc.) and the powerful DMA control method fully guarantee the stability and real-time performance of the fixed-wing UAV control system. The following is a detailed description of the flight control computer:

The flight control unit integrates the functions of flight control, navigation, and communication with the ground station. It is mainly responsible for reading the data of the remote controller, MIT attitude sensor, six-degree-of-freedom attitude sensor, three-degree-of-freedom magnetic field sensor, barometer, differential GPS, and airspeed meter, and is responsible for wireless data transmission with the ground station. Its function is based on receiving Received remote control, MIT attitude sensor, six-degree-of-freedom attitude sensor, three-degree-of-freedom magnetic field sensor, barometer, differential GPS, airspeed meter data, real-time calculation of the route to give fixed-wing UAV navigation and flight control, and output control The command is given to the electronic governor to control the speed of the motor and the control command is given to the steering gear to control the rudder surface. In the utility model, the attitude sensor flight adopts high and low collocation double redundancy. During normal flight, the attitude and heading data are provided by the mounted MTI, and the onboard attitude sensor (six degrees of freedom attitude sensor, three degrees of freedom magnetic field sensor) Combination) module as a backup and comparison monitoring signal. The flight control unit continuously detects the data of MTI. When the data is lost or the data remains unchanged, it is considered that the MTI module fails, and the onboard attitude sensor provides attitude and heading data to ensure the stable flight of the fixed-wing UAV. Altitude information also adopts high and low precision dual redundancy control. Although the differential GPS received data has high accuracy and the error is within 10cm, the data depends on the base station, and the data may be lost. Therefore, the low-precision barometer altitude is used as backup and monitoring. When the differential GPS fails, the barometer provides altitude information to ensure the stable flight of the fixed-wing UAV. Among them, the control principle of the flight control unit is a conventional technical means, such as (Liu Yanbo. Autonomous flight control law design of small fixed-wing UAV [D]. The design and simulation of the flight control system [D]. Beijing Institute of Technology, 2015.) are introduced.

(2) Design of sensor module

The sensor system used in the present invention comprises:

① Attitude sensor: high-precision MTI attitude sensor, low-precision MPU6000 and HMC5883l combined nine-degree-of-freedom attitude sensor, forming a double redundancy of the attitude sensor.

The MTI attitude sensor uses the MTI-300 from XSENS, which has excellent performance against mechanical vibration and impact, and can directly output high-precision data such as 3-degree-of-freedom angle, 3-degree-of-freedom angular rate, and 3-degree-of-freedom acceleration. Under static conditions, the measurement deviation of roll angle and pitch angle is between 0.2°-0.25°; under dynamic conditions, the measurement deviation is between 0.3°-1.0°, and the maximum deviation of yaw angle measurement is 1.0°. Provides up to 2kHz output data frequency and less than 2ms data latency.

The six-degree-of-freedom attitude sensor uses the MPU-6000 produced by Invensense of the United States, which integrates a 3-degree-of-freedom gyroscope and a 3-degree-of-freedom accelerator, and is the world's first integrated 6-degree-of-freedom motion processing component. Compared with the multi-component solution, MPU-6000 eliminates the problem of inter-axis difference when combining gyroscopes and accelerators, reduces a lot of packaging space, and has the characteristics of low power consumption, low cost, and high performance.

The three-degree-of-freedom magnetic field sensor uses Honeywell's HMC5883L. The sensor can achieve a resolution of 5 milligauss in a magnetic field of ±8 gauss, and has a built-in self-test function, which can make the compass heading accuracy accurate to 1°-2°. It adopts Honeywell's anisotropic magnetoresistance (AMR) technology, It has the characteristics of high sensitivity in the axial direction and high linear precision.

The MTI attitude sensor is connected to the flight control power supply through the serial port, and the six-degree-of-freedom attitude sensor and the three-degree-of-freedom magnetic field sensor are connected to the flight control unit through I2C.

②Wireless data transmission module

The wireless data transmission module is a method used to remotely control the drone in this invention, and its control range determines the flight radius of the drone. The wireless data transmission module is used to realize data mutual transmission between the ground station on the ground and the flight control system carried by the UAV in the air. The utility model selects 3DR Radio Telemetry data transmission module, the transmission frequency is 915MHz, the maximum transmission distance is 700m, and the UART interface is used to output data.

③Barometer

The barometer adopts a new generation of high-resolution air pressure sensor MS5611 launched by MEAS, which is used to measure the absolute flight height of fixed-wing aircraft (relative to the height of the take-off point). The module contains a high linearity pressure sensor and an ultra-low power 24-bit analog-to-digital converter, which provides an accurate 24-bit digital pressure value and temperature value and different operating modes, which can improve the conversion speed and optimize the current consumption. High-resolution temperature output enables altimeter/thermometer functionality without additional sensors. Working temperature range: -40-85°C, accuracy: at a flight altitude of 750m, the deviation is -1.5m～+1.5m.

④Differential GPS

The utility model uses the OEM617 launched by NovAtel, which has the characteristics of modularization and provides flexible configuration for the user's application. Provides decimeter-level positioning accuracy.

⑤Airspeed meter

The utility model uses the airspeed gauge differential pressure sensor of model MS4525DO-DS5AI001DS, which is a digital output, and is a small pressure sensor with a ceramic base and a circuit board installed for measurement. It sends the speed of the aircraft relative to the air back to the flight controller through the I2C bus to control the speed of the drone.

⑥EEPROM

The utility model adopts T24C256 as EEPROM, T24C256 is ATMEL 256kbit serial electrically erasable programmable read-only memory, 8-pin double row in-line package, compact structure, large storage capacity, and transmits information through I2C bus and flight control , which is mounted on the flight control board.

⑦Power module

The utility model uses a 10000mAh, 25C, 22.2V lithium battery to supply power for the flight power of the multi-rotor UAV. The power supply of the flight control unit needs to be stepped down to provide two DC power supplies of 5V and 3.3V to meet the needs of the control chip. Use the MP2482 chip to achieve a stable output of 5V from the power battery; use the MIC5219-3.3 produced by the American MICREL company to achieve a low voltage drop of 5V→3.3V, which can achieve high efficiency, low cost, low noise, and low quiescent current.

The automatic flight control system designed by the utility model can set the route and the flight action of the fixed-wing UAV through the ground station, such as take-off, landing, and route tracking, and transmit the route information to the airborne part through the wireless data transmission module.

The utility model uses 100Hz as the control frequency to complete the analysis of the attitude sensor and the calculation of the control law. After conversion, the PWM value is output to the motor and steering gear to drive the fixed-wing UAV to complete the route flight.

The above is only a specific embodiment of the utility model, but the scope of protection of the utility model is not limited thereto, anyone familiar with the technology can understand the conceived transformation within the technical scope disclosed in the utility model Or replacement, all should be covered within the scope of the present utility model, therefore, the protection scope of the present utility model should be based on the protection scope of the claims.

Claims (6)

1. the fixed-wing unmanned plane automatic flight control system of a double redundant sensors, it is characterised in that include airborne portion With earth station's part；

Described airborne portion includes fixed-wing unmanned plane body, aviation mechanism, flight control units, remote control receiver, sensing Device module, wireless data transmission module, battery module；

Described aviation mechanism includes electron speed regulator, motor, blade, steering wheel, and wherein, blade is arranged on motor；Motor is positioned at Fixed-wing unmanned plane head front end, is connected with flight control units by electron speed regulator；Steering wheel is used for controlling elevator, pair The wing, rudder, be connected with flight control units by PWM output driving circuit；

Described sensor assembly includes MIT attitude transducer, six-degree-of-freedom posture sensor, Three Degree Of Freedom magnetic field sensor, gas Pressure meter, differential GPS, pitot meter；

Described flight control units respectively with MIT attitude transducer, six-degree-of-freedom posture sensor, Three Degree Of Freedom magnetic field sensing Device, barometer, differential GPS, pitot meter, remote control receiver, wireless data transmission module, battery module connect；

Described earth station part includes control module, terrestrial wireless digital transmission module and remote controller, wherein, terrestrial wireless digital transmission module Communicate wirelessly with the wireless data transmission module of airborne portion.

The fixed-wing unmanned plane automatic flight control system of a kind of double redundant sensors the most according to claim 1, it is special Levying and be, described motor is connected with fixed-wing unmanned plane by linkage.

The fixed-wing unmanned plane automatic flight control system of a kind of double redundant sensors the most according to claim 1, it is special Levying and be, described MIT attitude transducer uses the mode of carry, is connected with flight control units by UART.

The fixed-wing unmanned plane automatic flight control system of a kind of double redundant sensors the most according to claim 1, it is special Levying and be, described six-degree-of-freedom posture sensor, Three Degree Of Freedom magnetic field sensor and barometer use onboard mode, pass through I2C bus is connected with flight control units.

The fixed-wing unmanned plane automatic flight control system of a kind of double redundant sensors the most according to claim 1, it is special Levying and be, wireless data transmission module is connected with flight control units by UART serial ports, and pitot meter module passes through I2C bus and flight Control unit connects.

The fixed-wing unmanned plane automatic flight control system of a kind of double redundant sensors the most according to claim 1, it is special Levy and be, also include the EEPROM module being connected with flight control units by I2C bus.