CN102424112B - Three-layer airborne flight control device for micro four-rotor aerial vehicle - Google Patents

Abstract

A three-layer airborne flight control device for a micro quadcopter belongs to the field of micro aircraft technology. The navigation control layer consists of a navigation controller, an inertial measurement unit, a micro laser rangefinder, a micro vision sensor, and a WiFi wireless network. The attitude control layer consists of an attitude controller, a gyroscope, an accelerometer, a magnetometer, a pressure sensor, an ultrasonic sensor, a remote controller, a receiver unit, and a ZigBee wireless communication unit. The motor speed control layer consists of four brushless motor speed controllers and four actuator units. This invention adds an attitude controller, making the entire flight device intelligent, capable of autonomous navigation and positioning, obstacle avoidance, and eliminating reliance on manual operation of the remote controller, thus becoming an intelligent robot in a true sense.

Description

Three-layer airborne flight control device for micro quadrotor aircraft

technical field

The invention belongs to the technical field of micro-aircraft, and in particular relates to a three-layer airborne flight control device of a miniature four-rotor aircraft.

Background technique

Micro Aerial Vehicle (MAV: Micro Aerial Vehicle) has the characteristics of small size, light weight, easy to carry, simple operation, good concealment, and flexible maneuverability. More and more researchers in the field of robotics and aviation are paying attention. In the military, micro-aircraft can be used for enemy reconnaissance, target tracking, electronic interference, damage assessment, nuclear, biological and chemical sampling, deployment of sensors, relay communications, and even active offense and defense; in civilian use, micro-aircraft can be used for various types of monitoring, monitoring, patrolling , search and rescue, photography, surveying and mapping, surveys and expeditions.

Although the initial drone market was mainly for military use and was expensive, in recent years, due to the development of miniaturization, mechatronics and microelectronics technology, it has become possible to commercially apply tiny, low-cost drone systems. This kind of micro drone can be used in both indoor and outdoor environments, so it has a new application field that is completely different from traditional drones. However, indoor flying also brings challenges in terms of size, weight and mobility of drones, making many types of aircraft unable to meet the above requirements. Wherein a kind of aircraft that can be widely used in both indoor and outdoor environment is exactly rotor type, especially miniature four-rotor aircraft. The micro-quadrotor aircraft is a vertically ascending and descending aircraft driven by four-rotor propellers, and is widely used in the design of micro-aircrafts. The quadrotor is a non-coaxial disc-shaped aircraft in the overall layout, which can generate greater lift than conventional rotor aircraft. In addition, the quadrotors can cancel each other's anti-torque moments, and there is no need for special anti-torque propellers. In addition, it achieves stable hovering and precise flight by balancing the forces generated by the four rotors, and uses smaller propellers to make flying safer.

However, most of the micro-quadrotor flying robots proposed by most researchers are all oriented to open outdoor environments, and GPS positioning systems are often used to realize the autonomous flight of robots. However, the accuracy of the GPS position signal is highly dependent on the number of satellites used to calculate the position and the quality of the received signal. Due to the multi-path propagation characteristics of electromagnetic waves, electromagnetic interference with airborne equipment, and human interference, etc., GPS positioning will fail. Therefore, reliable GPS positioning signals are often not available in urban areas and indoor environments with tall buildings. In addition, since most of the current micro-flying robot systems lack an odometer system, disastrous consequences will be produced when there is no GPS signal or the GPS signal is wrong. Therefore, the current miniature four-rotor flying robot is still not suitable for autonomous search, rescue, environmental detection and monitoring in areas such as indoors, dangerous mines, tunnels, and urban areas with dense buildings.

Contents of the invention

Aiming at the deficiencies of existing devices, the present invention proposes a three-layer airborne flight control device for a miniature four-rotor aircraft, so as to achieve the purpose of autonomous navigation and positioning without GPS positioning.

The technical solution of the present invention is achieved in the following way: a three-layer airborne flight control device for a miniature four-rotor aircraft, comprising: an attitude controller, a gyroscope, an accelerometer, a magnetometer, a pressure sensor, an ultrasonic sensor, and a remote controller And receiver unit, ZigBee wireless communication unit, brushless motor speed controller, actuator unit and power supply battery, also includes navigation controller, inertial measurement unit, miniature laser ranging sensor, miniature vision sensor, WiFi wireless network;

The navigation controller, the inertial measurement unit, the miniature laser ranging sensor, the miniature vision sensor and the WiFi wireless network form the navigation control layer to realize the precise positioning of the area without GPS signal;

The attitude controller, gyroscope, accelerometer, magnetometer, pressure sensor, ultrasonic sensor, remote controller and receiver unit and ZigBee wireless communication unit form the attitude control layer;

Four brushless motor speed controllers and four actuator units form the motor speed control layer;

The navigation control layer, the attitude control layer and the motor speed control layer form a three-layer airborne control structure; among them, the navigation control layer and the attitude control layer communicate through the USB serial port, and the navigation control layer processes the signals collected by its own sensors, and Pass the result to the attitude control layer;

The attitude control layer processes the signals collected by its own sensors or sends the signals collected by its sensors to the navigation control layer, and the navigation control layer processes the collected signals before returning to the attitude control layer;

The attitude control layer provides 4 PWM signals to control the motor speed control layer to work;

The inertial measurement unit is a sensor integrated with a gyroscope, an accelerometer and a magnetometer for measuring the angular rate and acceleration of an object, which ensures that the attitude control layer still controls the speed control of the motor after the navigation control layer is removed. Layer works normally;

The brushless motor governor receives the control signal of the attitude control layer and adjusts the rotation speed of the brushless motor in the actuator unit;

The actuator unit includes a brushless motor and a matching propeller, which generates lift and drives the aircraft to run.

Advantages of the present invention: the navigation control layer is added in the present invention. After the navigation control layer is connected with the attitude control layer through the serial port, the intercommunication of sensor information data on each layer is realized. The navigation controller can transmit control signals to the attitude controller, and the attitude control The sensor information on the aircraft can also be uploaded to the navigation controller for calculation and processing. The entire flying device becomes intelligent, capable of autonomous navigation and positioning, avoiding obstacles and abandoning the manual operation dependence on the remote control, becoming an intelligent robot in the sense.

Description of drawings

Fig. 1 is a three-layer airborne flight control device general structure block diagram of a kind of miniature four-rotor aircraft of the present invention;

Fig. 2 is the structural representation of the navigation control layer of the three-layer airborne flight control device of a kind of miniature four-rotor aircraft of the present invention;

Fig. 3 is the structural schematic diagram of the attitude control layer of the three-layer airborne flight control device of a kind of miniature four-rotor aircraft of the present invention;

Fig. 4 is a three-layer airborne flight control device motor speed regulation control layer structural frame schematic diagram of a kind of miniature four-rotor aircraft of the present invention;

5 is a schematic diagram of a brushless motor and a propeller of a three-layer airborne flight control device of a miniature quadrotor aircraft according to the present invention.

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings and embodiments.

The overall structure of the three-layer airborne flight control device of the miniature four-rotor aircraft is shown in Figure 1. In this embodiment, the model of the navigation controller is M-PMI2-1.5, the model of the inertial measurement unit is MTi_AHRS, and the miniature laser measurement unit is MTi_AHRS. The model of distance sensor is URG-04LX, the model of miniature vision sensor is FFMU-03MTM/C, the model of attitude controller is ArduinoMEGA2560, the model of gyroscope is ITG-3200, the model of accelerometer is BMA180, the model of magnetometer is The model is HMC5843, the model of the pressure sensor is BMP085, the model of the ultrasonic sensor is PING, the model of the remote control is FT06-C, the model of the receiver is FRP06-P, the model of the wireless communication module expansion board is XBee Shield V1.0, The model of the wireless communication module is XBee Pro XBP24-AWI-001, the model of the USB adapter of the wireless communication module is XBee USBAdapter, the models of the 4 brushless motor speed controllers are HOBBYWING PENTIUM-30A, and the 4 actuator units are brushless Motor, its model is A2212KV1000.

In this embodiment, a three-layer airborne flight control device of a miniature four-rotor aircraft, the connection relationship of each component is as follows:

Navigation control layer: the data input terminal of the navigation controller is connected to the output terminal of the inertial measurement unit, the output terminal of the miniature laser ranging sensor and the output terminal of the miniature vision sensor, and the wireless signal input and output terminal of the navigation controller is connected to the input of the WiFi wireless network output terminal;

Attitude control layer: the data input terminal of the attitude controller is connected to the output terminal of the gyroscope, the output terminal of the accelerometer, the output terminal of the magnetometer, the output terminal of the pressure sensor and the output terminal of the ultrasonic sensor, the attitude controller and the remote control and The signal output terminal of the receiver unit is connected, and the wireless communication port of the attitude controller is connected to the input and output terminals of the ZigBee wireless communication unit;

Motor speed control layer: the output end of the brushless motor speed controller is connected to the input end of the actuator unit;

The power supply battery supplies power to each component in the three-layer airborne flight control device of the miniature quadrotor aircraft.

Figure 2 is a schematic diagram of the structure of the navigation control layer. The navigation controller is the brain of the entire airborne flight control device. The image data collected by the visual sensor, and the real-time data of the distance between the aircraft and the surrounding objects collected by the miniature laser ranging sensor realize the positioning, navigation and map creation of the flight control device, and realize accurate navigation and positioning in areas without GPS signals. It solves the problem that reliable GPS positioning signals cannot be obtained due to the multipath propagation characteristics of electromagnetic waves and electromagnetic interference from other electronic equipment in urban areas and indoor environments where high-rise buildings stand tall.

The navigation controller M-PMI2-1.5 that the present embodiment adopts is single-board computer, accords with PC/104 agreement standard (PC/104, PC/104-Plus, PCI/104 and PCI/104-Express), M-PMI2 -1.5 is an embedded mainboard, which integrates processor, chipset and peripheral interface connectors. Its 4 USB ports and 1 COM1 serial ports are used in the present embodiment, and 4 of them are provided on the embedded mainboard. USB2.0 socket, each USB2.0 socket has 4 pins, representing the signal USBVcc, USB-, USB+, GND, insert the first attached cable provided by the manufacturer into the 4 pins of the USB2.0 socket, The other end of the attached wiring is the normal USB output interface. There are 4 USB output ports on the embedded motherboard, namely USB1, USB2, USB3 and USB4. The COM1 serial port on the embedded motherboard conforms to the RS232 protocol. It is a 10-pin jack , of which 9 pins have signal definitions, one end of the second attached wiring provided by the manufacturer is inserted into the COM1 serial port, and the other end of the second attached wiring is used as the output end; the entire navigation controller works at +5V voltage, and there are two power ports on the main board Both Power1 and Power2 are 10-pin jacks, pins 1, 7, and 9 represent grounding GND, and pins 2, 8, and 10 represent +5V. This embodiment uses one of the power ports, Power1, and leads it out with the attached wiring provided by the manufacturer. , connected to the switch, and then connected to the power supply lithium battery;

The model measured by the inertial measurement unit is IMU, which is a sensor integrating a gyroscope, an accelerometer and a magnetometer. The output end of the second attached wiring of the navigation controller is connected to the 7-core round socket of the inertial measurement unit. The navigation control The USB1 end of the controller is connected to the MinUSB1 end of the miniature vision sensor, the USB2 port of the navigation controller is connected to the MiniUSB2 port of the miniature laser ranging sensor, the USB3 port of the navigation controller is connected to the output end of the wireless network card WLG-12254M, and the USB4 port of the navigation controller Connect the serial port to the USB port of the attitude controller through the USB cable; the Power1 port of the navigation controller leads out +5V and GND signals, respectively connects the +5V and GND signals of the Power port of the miniature laser ranging sensor, and then connects the upper layer switch and the power supply lithium Battery; Wherein, described miniature laser ranging sensor can not be directly powered by USB;

The block diagram of the attitude control layer is shown in Figure 3. The attitude controller is realized by a single-chip microcomputer. Generally, the aircraft recording device built by the attitude control layer and the motor speed control layer can also realize the attitude flight of the aircraft, but it needs a remote control for manual control. , and the attitude controller needs an additional PC support. In this embodiment, a navigation control layer is added. After the navigation control layer is connected to the attitude control layer through a serial port, the intercommunication of sensor information data on each layer is realized. The navigation controller can Transmit control signals to the attitude controller, and the sensor information on the attitude controller can also be uploaded to the navigation controller for calculation and processing. Intelligent robots in the sense.

The D2～D7 terminals of the attitude controller are sequentially connected to the THRO (throttle) terminal, ALLE (aileron) terminal, ELEV (elevator) terminal, RUDO (direction) terminal, GEAR (landing gear/gyroscope) terminal and AUX ( Flap/pitch) terminal, SDA serial data terminal A4 and serial clock terminal A5 of the attitude controller are respectively connected to the SDA-H terminal and SCL-H terminal of the logic level converter, and the SDA terminal of the logic level converter is respectively Connect the data terminal of the magnetometer, the SDA terminal of the accelerometer, the SDA terminal of the gyroscope and the SDA terminal of the pressure sensor, and connect the SCL terminal of the logic level converter to the SCL terminal of the magnetometer, the SCL terminal of the accelerometer, and the gyro The SCL terminal of the meter and the SCL terminal of the pressure sensor, the +3.3V terminal of the logic level converter are respectively connected to the +3.3V terminal of the magnetometer, the +3.3V terminal of the accelerometer, the +3.3V terminal of the gyroscope and the pressure sensor The +3.3V terminal of the logic level converter and the GND terminal of the logic level converter are respectively connected to the GND terminal of the magnetometer, the +GND terminal of the accelerometer, the GND terminal of the gyroscope and the GND terminal of the pressure sensor; the D20 port of the attitude controller is connected to the ultrasonic The SIG end of the sensor, the D8-D11 end of the attitude controller are connected to the input ends of the four brushless motor governors through pins 1 to 4 on the interface circuit board, and the TX end and RX end of the I/O end of the attitude controller. The terminal is connected to the DI terminal and DOUT terminal of the first ZigBee wireless communication module through the Xbee expansion board, and the +3.3V terminal and the GND terminal of the attitude controller are connected to the +3.3V terminal and the GND terminal of the first ZigBee wireless communication module through the Xbee expansion board; The DI terminal and DOUT terminal of the second Zigbee are connected to the DI terminal and DOUT terminal of the USB adapter, and the USB adapter is connected to the ground station through the USB terminal;

The inertial measurement unit on the upper layer is a sensor that integrates gyroscope, accelerometer, and magnetometer. Its measurement accuracy is higher than that of this layer. The introduction of inertial measurement unit is not redundant. Compensation for errors and cross-axis effects of sensors can compare and correct data information; the use of a single gyroscope, accelerometer, and magnetometer in the middle layer enables the aircraft to still provide real-time attitude data for the system after removing the upper navigation control layer.

The operating voltage of the sensor in the attitude control layer is 3.3V, while the operating voltage of the single-chip microcomputer used by the attitude controller is 5V, which needs to be equipped with a 5V-3.3V logic level converter. Therefore, the analog input terminals A4 and A5 of the attitude controller are used as serial Line digital SDA and serial clock SCL signal terminals, add the converted level +3.3V and ground GND, and connect with gyroscope, accelerometer, magnetometer sensor, and pressure sensor in a bus way.

There is an encoding circuit in the remote control, which modulates the electromagnetic wave, so that the electromagnetic wave carries a password. After the receiver receives the signal, it identifies the password and obtains the control signal. For the receiver, its working frequency band is 72MHz, and the working voltage range is 4.8 -6V, six channels, the antenna of the receiver is best wrapped around a thin plastic rod of about 30cm to ensure good radio frequency signal reception. When the remote control is working, the transmission power is less than or equal to 100mW, and the working current is less than or equal to 160mA.

The Zigbee wireless communication unit includes the Zigbee wireless communication module and the corresponding expansion board and USB adapter. The ground station can transmit control commands and tasks to the attitude controller, and at the same time receive information such as real-time data from the sensor. When the aircraft does not have an upper navigation control layer, it is more accurate. In other words, when there is no WiFi wireless network, it mainly relies on the wireless communication unit for communication. When the aircraft is far away from the ground, it needs to rely on the WiFi wireless network of the navigation control layer.

Figure 4 is a block diagram of the motor speed control layer structure, taking a brushless motor speed controller as an example to illustrate its connection relationship: the Vdd end of the brushless motor speed controller is connected to the Vdd end of the middle switch and then connected to the positive pole of the lithium battery. The GND terminal of the brush motor is connected to the GND terminal of the middle layer switch and then connected to the GND terminal of the lithium battery. The input terminal of the brushless motor speed controller is connected to the S terminal of pin 1 on the interface circuit board of the attitude controller, and the speed of the brushless motor is adjusted. The +5V terminal of the controller is connected to the +5V terminal of the attitude controller, the GND terminal of the brushless motor governor is connected to the GND terminal of the attitude controller, and the three-phase voltage output terminals A, B and C of the brushless motor governor are respectively connected to The three-phase motor input terminal of the brushless motor; the connection method of the four brushless motors is the same;

Figure 5 is a schematic diagram of the structure of the brushless motor and the corresponding supporting propeller of the miniature quadrotor aircraft. The four rotors are respectively installed at the four vertices of the brushless motor, divided into two groups of clockwise and counterclockwise, located on the same diagonal The two rotors are in the same group, that is, the front and rear 1, 2 rotors are in the same group, and the left and right 3, 4 rotors are in the same group. Since the rotors are diagonally fixed, the flight control of the aircraft can only be realized by controlling the rotation speed of the four rotors. When hovering, the rotational speeds of the four rotors are equal to offset the anti-torque torque; increasing or decreasing the rotational speeds of the four rotors at the same time will cause an upward or downward movement; increasing the rotational speed of a certain rotor at the same time , reducing the rotation speed of the other rotor in the same group by the same amount can produce pitch or roll rotation; increasing the rotation speed of one group of rotors and reducing the rotation speed of the other group of rotors by the same amount will produce yaw motion . Therefore, there are pros and cons for the choice of propellers, and there are also pros and cons for the rotation of brushless motors. In this embodiment, the model of the brushless motor is A2212 KV1000, where the KV value represents the value that the speed of the brushless motor increases when the voltage increases by 1V. The speed of the brushless motor is fast enough to provide the lift of a micro-aircraft.

Claims (4)

1. three of a microminiature quadrotor layers airbornely fly to control device, comprise: attitude controller, gyroscope, accelerometer, magnetometer, pressure sensor, ultrasonic transduter, remote controller and acceptor unit, ZigBee radio communication unit, brushless motor governor, actuator unit and supplying cell, is characterized in that: also comprise navigation controller, Inertial Measurement Unit, miniature laser distance measuring sensor, miniature vision sensor, WiFi wireless network;

Described navigation controller, Inertial Measurement Unit, miniature laser distance measuring sensor, miniature vision sensor and WiFi wireless network form Navigation Control layer, realize the accurate location without gps signal region;

Described attitude controller, gyroscope, accelerometer, magnetometer, pressure sensor, ultrasonic transduter, remote controller and acceptor unit and ZigBee radio communication unit form attitude key-course;

Four brushless motor governors and four actuator units form electric machine speed regulation key-course;

Navigation Control layer, attitude key-course and electric machine speed regulation key-course form three layers of airborne control structure; Wherein, Navigation Control layer and attitude key-course carry out communication by USB serial ports, and the signal that Navigation Control layer collects self-sensor device is processed, and result is passed to attitude key-course;

The signal that the signal that described attitude key-course collects self-sensor device is processed or its sensor is collected sends to Navigation Control layer, after by Navigation Control layer, the signal collecting being processed, returns to attitude key-course again;

Described attitude key-course provides 4 road pwm signals to control the work of electric machine speed regulation key-course.

2. three of a kind of microminiature quadrotor according to claim 1 layers airbornely fly to control device, it is characterized in that: the gyroscope in described attitude key-course, accelerometer and magneticintensity meter, guarantee after removing Navigation Control layer, attitude key-course is still controlled the normal operation of electric machine speed regulation key-course.

3. three of a kind of microminiature quadrotor according to claim 1 layers airbornely fly to control device, it is characterized in that: described brushless motor governor is accepted the velocity of rotation of brushless motor in the control signal of attitude key-course adjusting actuator unit.

4. three of a kind of microminiature quadrotor according to claim 1 layers airbornely fly to control device, it is characterized in that: described actuator unit comprises brushless motor and supporting screw propeller with it, by it, is produced lift and is driven aircraft to move.

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