CN205281183U - A low-altitude environmental monitoring UAV system - Google Patents

Abstract

The utility model discloses a low-altitude environment monitoring unmanned aerial vehicle system, comprising a barometric altimeter, a geomagnetic sensor, a gyroscope, an accelerometer, a Beidou differential positioning system, an inertial measurement unit, a task equipment interface, a wireless transmission module, a PWM signal isolation module, Flight control computer, power supply module and ground station, the flight control computer is respectively connected with barometric altimeter, geomagnetic sensor, gyroscope, accelerometer, Beidou differential positioning system, inertial measurement unit and PWM signal isolation module, the flight control computer is connected through the wireless transmission module Connected with the ground station, the power supply module provides power support for the entire system, and the mission equipment interface is connected to the mission equipment. The utility model provides a low-altitude environment monitoring unmanned aerial vehicle system, which adopts a modular design concept and uses the Beidou dual-mode differential positioning technology to enable the unmanned aerial vehicle to operate in some ultra-low-altitude special environments with a height ranging from tens of centimeters to several meters. Fast real-time monitoring.

Description

A low-altitude environmental monitoring UAV system

technical field

The utility model belongs to the technical field of unmanned aerial vehicles, and in particular relates to a rapid monitoring unmanned aerial vehicle system for special environments such as ultra-low altitudes with a height ranging from tens of centimeters to several meters.

Background technique

An aircraft that does not require a driver is called an unmanned aerial vehicle (UnmannedAerialVehicle, UAV), also known as a drone. Devices such as aerial cameras, surveying and mapping instruments, relay communication nodes, and small-scale lethal weapons are mounted on UAVs, and they fly along specific routes under manual remote control or autonomous flight status to complete corresponding tasks. In recent years, there is still a lack of effective means for environmental monitoring with fast time requirements and low distance requirements.

Micro or small unmanned aerial vehicles not only have a simple mechanical structure, but also have more flexible flight maneuverability. In addition, the small six-rotor UAV has more flexible maneuverability, can take off, hover, fly and land in a small area, and can get close to the target area due to its small size and flexible maneuverability. And because of its special fuselage structure, the ground effect is not obvious when flying close to the ground, so it is very suitable for special occasions such as ultra-low altitude flight with a flight height in the range of tens of centimeters to several meters.

With the development of science and technology, the application field of drones has gradually transitioned from military use to civilian and police use. Whether it is in civil fields such as meteorological surveys, disaster investigations, and environmental protection, or in the police fields for chasing fugitives and disrupting terrorist activities, there is a lot of room for demand. However, most of the existing small UAV technologies are still unable to complete dynamic monitoring and regular monitoring in special environments such as low-altitude flight and some mountainous areas with high precision, and the environmental adaptability cannot meet actual needs, while low-altitude remote sensing dynamic monitoring and emergency monitoring are mainly used for Small-scale repeated dynamic monitoring, etc.

Utility model content

In order to solve the deficiencies in the prior art, the utility model provides a low-altitude environmental monitoring UAV system, which adopts a modular design idea and uses the Beidou dual-mode differential positioning technology to enable the UAV to operate at some heights at tens of Real-time rapid monitoring in ultra-low altitude special environments ranging from centimeters to several meters.

In order to solve the above problems, the utility model specifically adopts the following technical solutions:

A low-altitude environmental monitoring unmanned aerial vehicle system is characterized in that it includes a barometric altimeter, a geomagnetic sensor, a gyroscope, an accelerometer, a Beidou differential positioning system, an inertial measurement unit, a mission equipment interface, a wireless transmission module, a PWM signal isolation module, and a flight Control computer, power supply module and ground station, described flight control computer is connected with barometric altimeter, geomagnetic sensor, gyroscope, accelerometer, Beidou differential positioning system, inertial measurement unit and PWM signal isolation module respectively, and described flight control computer passes The wireless transmission module is connected with the ground station, the power supply module provides power support for the whole system, and the mission equipment interface is connected with the mission equipment. The flight control computer is responsible for collecting the information of each airborne sensor; receiving the control commands and data transmitted by the onboard radio measurement and control system from the uplink channel of the ground measurement and control station, and performing data processing, so as to realize the control laws and tasks of various flight modes Management, control signal output, status information transmission and other functions. The flight control computer requires real-time, reliability and embedded characteristics. Real-time requires that the input navigation data be processed at the fastest speed and output control signals with the shortest delay. Reliability requires strong anti-interference ability, wide operating temperature range and anti-electromagnetic interference. Embedding requires as small a volume and light weight as possible.

The aforementioned low-altitude environment monitoring UAV system is characterized in that the barometric altimeter is a digital air pressure sensor for realizing UAV navigation and positioning.

The aforementioned low-altitude environment monitoring UAV system is characterized in that the geomagnetic sensor is a high-precision three-axis digital geomagnetic sensor for measuring the heading of the UAV, which is responsible for measuring the heading of the aircraft.

The aforementioned low-altitude environment monitoring UAV system is characterized in that the gyroscope is a yaw angular velocity sensor that measures the angular variation of the UAV per unit time.

The aforementioned low-altitude environment monitoring UAV system is characterized in that the accelerometer is a three-axis acceleration sensor that measures the acceleration in each direction of the UAV's three-dimensional space domain, and is responsible for measuring the acceleration in each direction of the three-dimensional space domain of the aircraft.

The aforementioned low-altitude environment monitoring UAV system is characterized in that the mission equipment includes aerial photography equipment, gas detectors, and meteorological parameter detectors.

The aforementioned low-altitude environment monitoring UAV system is characterized in that the PWM signal isolation module is equipped with 6 DC brushless motors, and the motor speed is controlled by adjusting the voltage to control the UAV flight speed.

The aforementioned low-altitude environment monitoring unmanned aerial vehicle system is characterized in that the Beidou differential positioning system includes a GPS receiver, a GPS antenna and the second generation of Beidou, the GPS receiver is connected with a flight control computer, and the Beidou two The generation is connected with the GPS receiver through the GPS antenna.

The aforementioned low-altitude environment monitoring unmanned aerial vehicle system is characterized in that the unmanned aerial vehicle is a small multi-rotor unmanned aerial vehicle.

Beneficial effects of the utility model: the utility model provides a low-altitude environment monitoring unmanned aerial vehicle system, which has a simple mechanical structure and more flexible flight maneuverability. Moreover, the UAV is small in size and can approach the target area at close range, making up for the lack of sensitivity of robot monitoring vehicles in complex tunnels, mountains and forests and other ultra-low-altitude environments; in addition, the Beidou/GPS dual-mode system not only has high precision, but also Beidou also has the function of short message communication in special environments, which can make up for problems such as external interference or complete communication interruption in complex environments such as low altitudes of more than ten centimeters and some mountainous areas, and has a good application prospect.

Description of drawings

Fig. 1 is the structural block diagram of the low-altitude environmental monitoring unmanned aerial vehicle system of the present utility model;

Fig. 2 is a barometer data processing block diagram of the present utility model;

Fig. 3 is the barometric altimeter schematic diagram of the utility model;

Fig. 4 is the schematic diagram of the geomagnetic sensor of the present utility model;

Fig. 5 is the schematic diagram of the accelerometer of the present utility model;

Fig. 6 is a schematic diagram of the gyroscope of the present invention.

The reference signs have the following meanings:

1: Barometric altimeter; 2: Geomagnetic sensor; 3: Gyroscope; 4: Accelerometer; 5: Beidou differential positioning system; 6: Inertial measurement unit; 7: Mission equipment interface; 8: Wireless transmission module; 9: PWM signal isolation module; 10: flight control computer; 11: power supply module; 12: ground station.

detailed description

Below in conjunction with accompanying drawing and specific embodiment the utility model is described further.

As shown in Figure 1, a low-altitude environment monitoring UAV system includes a barometric altimeter 1, a geomagnetic sensor 2, a gyroscope 3, and an accelerometer 4, which provide real-time information on altitude, attitude angle, angular velocity, and acceleration data for the UAV. , The Beidou differential positioning system that provides real-time three-dimensional position and time data for UAVs 5, the inertial measurement unit (IMU) that provides real-time attitude data and positioning data 6, mission equipment interfaces connected with mission equipment 7, guarantee UAVs The wireless transmission module 8 with good communication with the ground station, the PWM signal isolation module 9 that can control the flight actions of the UAV by adjusting the motor speed, the flight control computer 10 that controls the UAV to complete navigation and plan tasks, and provide the entire system The power supply module 11 supported by electric power and the ground station 12 that exchanges relevant information such as attitude and position with the UAV in real time. The positioning system 5 , the inertial measurement unit 6 and the PWM signal isolation module 9 are connected, and the flight control computer 10 is connected with the ground station 12 through the wireless transmission module 8 . Wherein, the barometric altimeter 1 is a digital air pressure sensor for realizing the navigation and positioning of the drone, the geomagnetic sensor 2 is a high-precision three-axis digital geomagnetic sensor for measuring the heading of the drone, and the gyroscope 3 is for measuring the The yaw rate sensor of the angle change amount per unit time, the accelerometer 4 is a three-axis acceleration sensor that measures the acceleration in each direction of the three-dimensional space domain of the drone, and is used in combination with the above-mentioned geomagnetic sensor 2 to accurately compass heading information. The mission equipment that can be carried by the mission equipment interface includes multiple equipment such as aerial photography equipment, gas detectors, and meteorological parameter detectors, and collects various required parameter information. The wireless transmission module is an important part of the aircraft system. The man-machine and the ground station communicate through the wireless transmission part to exchange information such as flight attitude and position. In addition, the ground station includes a monitoring computer and a remote controller. The PWM signal isolation module 9 is a PWM signal isolation driving motor, which is equipped with 6 DC brushless motors. Further, the Beidou differential positioning system 5 includes a GPS receiver, a GPS antenna and the second generation of Beidou, the GPS receiver is connected to the flight control computer 10, and the second generation of Beidou is connected to the GPS receiver through the GPS antenna, Make full use of the positioning function of GPS and the short message communication function of Beidou. The flight control computer is the central control unit of the flight, which is responsible for the coordination among the components of the drone and the communication with the ground control station. The unmanned aerial vehicle used in the low-altitude environmental monitoring unmanned aerial vehicle system is a small multi-rotor unmanned aerial vehicle.

Further, the output of the barometric altimeter is a digital quantity representing the air pressure, and the main processor samples the barometer and the acceleration signal from the slave board at a frequency of 50HZ. Figure 2 is a data processing diagram of the barometer. Due to the inherent drift phenomenon of the sensor and the existence of high-frequency noise, the data value obtained only by the barometer or the acceleration sensor has a large error from the real data value, which requires a processing process as shown in Figure 2 to sample the two The final data is processed by data fusion technology to obtain high-precision height data values. As shown in Figure 3, the barometric altimeter adopts the Swiss MS5803-01BA digital air pressure sensor, which directly outputs digital signals and can be directly connected to the microprocessor through its SPI interface. It has low voltage (1.8V-3.6V), stable Good performance, low power consumption (working current 1μA; standby current <0.15μA), small size, high precision, etc., the measuring range is 10-1300mbar, and it can work at the temperature of -40℃-85℃, very suitable for field pressure and For height measurement, the resolution can reach ±0.1m. MS5803-01BA has both I ² C and SPI interfaces, the internal A/D converter is Δ-Σ type, the output is 24-bit pressure and temperature digital signals, and the fastest conversion time is 1ms. A computer or microprocessor can collect and process air pressure and temperature data through an I ² C or SPI interface.

As shown in Figure 4, the geomagnetic sensor uses Freescale's 3-axis digital magnetometer MAG3110, whose data update frequency can reach 80Hz, and the data output rate can be adjusted between 12ms and several seconds, with a built-in standard I ² C interface, its communication rate can reach 400kHz at the fastest, and it can measure the geomagnetic field with a magnetic field strength up to 10 gauss. SCL1 in the figure is connected to the clock signal line corresponding to the I ² C interface of the microprocessor on the main control board, and SDA1 is connected to the data signal line of the corresponding interface. Combining the MAG3110 with a 3-axis accelerometer enables accurate compass heading information.

In addition, the flight control computer 10 adopts STM32L as the control system microprocessor. The processor uses ARM Cortex-M4 32-bit core with a running frequency of 32kHz. In normal operation mode, the current consumption of the flash memory is as low as 230A/MHz, and the STM32L has the lowest power/performance ratio of 185A/DMIPS. The STM32L achieves high performance at low voltage, effectively extending the charging interval of battery-powered devices. The minimum operating supply voltage for digital functions is 1.65V, which can extend the operating time of battery-powered equipment when the battery voltage is reduced. The above barometric altimeter and geomagnetic sensor are mounted on the main control board, while the gyroscope and accelerometer are mounted on the slave control board, and the power required by the main control board is supplied by the slave control board.

As shown in Figure 5, the accelerometer uses a three-axis ADXL335 sensor, and the sensitivity of the accelerometer is affected by the supply voltage. When the supply voltage is 3.6V, the output sensitivity is 350mv/g; when the supply voltage is 2V, the output sensitivity is 190mv/g. In this example, the supply voltage designed for the ADXL335 module is 3V. XACC, YACC, and ZACC are respectively connected to the three channels corresponding to the built-in ADC of the microprocessor. C15, C16, and C17 are filter capacitors with a size of 0.47uf and a set bandwidth of 10Hz. U5 is a step-down regulator MCP1700 with low quiescent current voltage, and its output voltage is 3V, which provides the working voltage for the accelerometer. ADXL335 can control the bandwidth of its output pins Xout, Yout, and Zout. By introducing capacitors on the pins of Xout, Yout, and Zout respectively, a low-pass filter can be formed to reduce high-frequency noise.

As shown in Figure 6, the gyroscope adopts the ADXRS610 packaged in the BGA-32 ceramic shell of Analog Devices. Three single-axis ADXRS610s are used to measure the angular velocity around the x-axis, y-axis, and z-axis respectively. C7 is a power decoupling capacitor, C4 is a power decoupling capacitor, C1 and C5 are charging capacitors, and C6 is an HV filter capacitor. AVCC is connected to the positive analog voltage terminal of the power module, GND is the analog ground terminal; VDD is the input terminal of the charge power supply, and PGND is the ground terminal of the charge power supply; AVCC and VDD, PGND and AGND are isolated with 0 ohm resistors, and the rateout interface in P1 It is a voltage output signal, representing the magnitude of the angular velocity of the gyroscope, and this port is connected to the input channel of the built-in ADC of the microprocessor. The combination of external capacitor C2 and on-chip resistor Rout forms a low-pass filter, which can reduce the interference of high-frequency noise.

In view of the continuous improvement of the cognition and self-adaptive ability of aircraft in complex environments, multi-sensor cooperative work has become an effective way to solve this problem. The utility model provides an ultra-low-altitude environmental monitoring unmanned aerial vehicle system in special environments such as caves, tunnels, and mountainous areas, which can realize navigation control and unmanned aerial vehicle status in a variety of complex terrain environments within the range of tens of centimeters to several meters. Quick monitoring. Considering that UAVs are susceptible to interference from external environmental signals in the actual complex environment, the UAV system uses the PID control algorithm and the PID control algorithm based on disturbance observation to design the control law of the rotor UAV, which not only integrates A three-axis digital air pressure sensor with complete altitude control is installed, and a three-axis digital geomagnetometer, three-axis accelerometer, and gyroscope are also used to control the flight attitude of the drone in real time, and the central control unit performs data collection, calculation and data transmission. , its processor calculates and outputs 6 PWM signals to control the speed of the motor according to the existing sensor data and combined with related control algorithms, and then adjusts and controls the attitude and position of the UAV. The UAV and the monitoring computer are transmitted wirelessly The part communicates and exchanges relevant information such as attitude and position in real time, while the UAV completes the designated environmental monitoring task by receiving flight control instructions from the ground monitoring system. As a signal processing component, the main controller is responsible for the collection and processing of sensor signals, the calculation of attitude control and navigation control algorithms, rotor speed control, data communication, etc.; the sensor module consists of a three-axis gyroscope, a three-axis accelerometer, a three-axis Composed of geomagnetic sensor, barometric altimeter, GPS, etc., the power module is responsible for supplying power to all equipment on board; the remote control wireless link includes the remote control and its receiver, and the manual control of the quadrotor UAV can be realized through the remote control wireless link; communication The wireless link cooperates with the ground control station to complete the real-time monitoring of the flight status.

The basic principles, main features and advantages of the present utility model have been shown and described above. Those skilled in the art should understand that the utility model is not limited by the above-mentioned embodiments. The above-mentioned embodiments and descriptions only illustrate the principle of the utility model. Without departing from the spirit and scope of the utility model, the utility model The new model also has various changes and improvements, and these changes and improvements all fall within the scope of the claimed utility model. The scope of protection required by the utility model is defined by the appended claims and their equivalents.

Claims (9)

1. A low-altitude environment monitoring unmanned aerial vehicle system is characterized in that, comprises barometric altimeter, geomagnetic sensor, gyroscope, accelerometer, Beidou differential positioning system, inertial measurement unit, task equipment interface, wireless transmission module, PWM signal isolation module , flight control computer, power supply module and ground station, described flight control computer is connected with barometric altimeter, geomagnetic sensor, gyroscope, accelerometer, Beidou differential positioning system, inertial measurement unit and PWM signal isolation module respectively, described flight control The computer is connected with the ground station through the wireless transmission module, the power supply module provides power support for the whole system, and the mission equipment interface is connected with the mission equipment. 2. A kind of low-altitude environment monitoring unmanned aerial vehicle system according to claim 1, is characterized in that, described air pressure altimeter is the digital air pressure sensor that realizes unmanned aerial vehicle navigation and positioning. 3. A kind of low-altitude environment monitoring unmanned aerial vehicle system according to claim 1, is characterized in that, described geomagnetic sensor is the high-precision three-axis digital type geomagnetic sensor of measuring unmanned aerial vehicle course. 4. A kind of low-altitude environment monitoring unmanned aerial vehicle system according to claim 1, is characterized in that, described gyroscope is the yaw angular velocity sensor that measures the angular variation of unmanned aerial vehicle unit time. 5. A kind of low-altitude environment monitoring unmanned aerial vehicle system according to claim 1, is characterized in that, described accelerometer is the three-axis acceleration sensor that measures the acceleration of each direction of unmanned aerial vehicle three-dimensional space domain. 6. A kind of low-altitude environment monitoring unmanned aerial vehicle system according to claim 1, is characterized in that, described task equipment comprises aerial photography equipment, gas detector, meteorological parameter detector. 7. A low-altitude environment monitoring UAV system according to claim 1, wherein the PWM signal isolation module is configured with 6 brushless DC motors. 8. A kind of low-altitude environment monitoring unmanned aerial vehicle system according to claim 1, is characterized in that, described Beidou differential positioning system comprises GPS receiver, GPS antenna and Beidou two generations, described GPS receiver and flight control computer connected, the Beidou II is connected with the GPS receiver through the GPS antenna. 9. A kind of low-altitude environment monitoring unmanned aerial vehicle system according to claim 1, is characterized in that, described unmanned aerial vehicle is a small multi-rotor type unmanned aerial vehicle.