CN103149938A - Emergency landing method of unmanned aerial vehicle based on radio and laser guiding - Google Patents

Abstract

An emergency landing method for unmanned aerial vehicles based on radio and laser guidance. The equipment on which the method relies includes a laser scanner, a laser receiver and a data processor; the laser scanner is installed at the end of one end of the runway, and the scanning center is aligned with the center line of the runway. The lamellar laser beam is emitted with a scanning range of plus or minus 5 degrees to plus or minus 10 degrees. Two laser receivers are installed at the two ends of the wings of the drone, connected to the data processor through cables, and the data processor is installed In the equipment compartment of the drone; when the flight control system of the drone judges that the received GPS data is faulty, the emergency landing of the drone is realized through two parts: long-range radio guidance and short-range laser guidance.

Description

A UAV emergency landing method based on radio and laser guidance

technical field

The invention relates to a method for a UAV to land safely and accurately when the GPS device fails or the GPS signal is interfered and lost, which increases the safety of the UAV when it lands and improves the security conditions of the airport.

Background technique

When the UAV lands, it must approach the runway at a specific heading angle and altitude to land accurately. In this process, the traditional landing process is that the UAV uses the position information, altitude information, speed and direction information given by GPS to carry out navigation. track controlled. However, once the onboard GPS equipment fails or the GPS signal is interfered and lost, the entire guidance system will stop working, which will affect the safe landing of the UAV, and in severe cases, the UAV may even be lost and crashed. At present, in the safe recovery of taxiing, take-off and landing UAVs, few UAVs have emergency landing guidance systems. Less accurate radio guidance to land the drone reduces the chances that the drone can land safely. Therefore, with the role of UAV landing guidance in modern UAVs becoming more and more important, it is necessary to design a method for emergency landing guidance in the case of UAVs without GPS, so as to ensure the precise landing of UAVs. Increased safety when drones land.

Contents of the invention

The technical problem of the present invention is: to overcome the deficiencies of the prior art, to provide an emergency landing method for unmanned aerial vehicles based on radio and laser guidance, which can realize precise and safe landing of unmanned aerial vehicles without GPS.

The technical solution of the present invention is: a UAV emergency landing method based on radio and laser guidance, the equipment on which the method relies includes a laser scanner, a laser receiver and a data processor; the laser scanner is installed at the end of one end of the runway, The scanning center is aligned with the centerline of the runway, and a laminar laser beam is emitted within the scanning range of plus or minus 5 degrees to plus or minus 10 degrees. The processor is connected, and the data processor is installed in the equipment compartment of the UAV; when the flight control system of the UAV judges that the received GPS data fails, the steps of the emergency landing method are as follows:

(1) Shield the GPS data and switch to the radio guidance mode. The ground measurement and control station will send the distance, azimuth, pitch angle and GPS latitude and longitude information from the UAV to the ground measurement and control station by radio to the flight of the UAV. Control System;

(2) The flight control system of the UAV roughly calculates the longitude and latitude information of the UAV based on the received distance, azimuth, pitch angle, and GPS latitude and longitude information from the UAV to the ground measurement and control station. The flight control system conducts autonomous navigation according to the calculated latitude and longitude information until it flies into the approach window;

(3) According to the radio guidance of the ground measurement and control station, the UAV will fly at a fixed altitude along the center line of the runway;

(4) Enter the laser guide window, that is, the UAV flies to a position 8 to 10 kilometers away from the near end of the runway, and judge whether the laser receiver has received the laser information sent by the laser scanner. If not, go to step (5) ), otherwise go to step (6);

(5) The UAV maintains the original flight state, and continues to judge whether the laser receiver has received the laser information from the laser scanner during the process. At the same time, the flight control system judges whether the distance between the UAV and the near end of the runway is low. At 5 kilometers, if it is less than 5 kilometers, then control the UAV to go around and return to the field, and start again from step (4);

(6) The data processor determines the current direction of the UAV and the distance between the UAV and the laser scanner according to the received laser information, and the UAV flight control system adjusts the UAV to face the UAV according to the current direction of the UAV. Fly in the direction of the center of the runway, and control the UAV to land safely on the runway according to the distance between the UAV and the laser scanner.

Compared with the prior art, the present invention has beneficial effects as follows:

(1) In order to overcome the deficiency that the entire UAV guidance system stops working and cannot land safely once the airborne GPS equipment fails or the GPS signal is interfered and lost, the present invention designs an emergency response system applied to UAVs. The landing method, by dividing the landing process into two parts, long-distance guidance and short-distance guidance, respectively performs long-distance rough adjustment by radio, and fine-tunes by replacing the relevant information obtained by the GPS receiver with laser guidance, so as to ensure the safe landing of the drone .

(2) In the process of safe landing, the present invention adopts the traditional and reliable approach window, and by setting the landing safety minimum limit, when the laser information is received before entering the safety minimum limit, it can ensure that the UAV has enough time and distance Make a safe landing, otherwise, further improve the safety of drone landing by re-entry.

Description of drawings

Fig. 1 is a schematic diagram of the remote radio guidance process of the present invention;

Fig. 2 is a schematic diagram of the short-distance laser guidance process of the present invention;

Fig. 3 is a schematic diagram of the approach, emergency guidance and go-around of the unmanned aerial vehicle of the present invention;

Fig. 4 is a schematic diagram of laser scanning and guidance in the present invention;

Fig. 5 is a flow chart of the emergency landing method of the present invention.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings. In order to better understand the present invention, the equipment on which the present invention relies will be firstly explained below.

The devices upon which the invention is based include laser scanners, laser receivers and data processors;

The laser scanner is installed at the end of one end of the runway, and the scanning center is aligned with the centerline of the runway, and emits a sheet-shaped laser beam with a scanning range of plus or minus 5 degrees to plus or minus 10 degrees, and the scanning frequency is constant.

Two laser receivers are installed at the two ends of the UAV's wing, and are connected to the data processor through a cable. The data processor is installed in the equipment compartment of the UAV, and connected to the flight control computer through a serial port.

As shown in Figure 5, when the UAV is performing a mission, the computer of the ground measurement and control station continuously compares the position data sent by the GPS receiver of the ground measurement and control station with the actual position data of the measurement and control station to obtain the position correction value, and through the ground measurement and control The station's radio station transmits. The airborne computer processes the aircraft position data sent by the GPS receiver and the position correction value sent by the radio receiver to obtain more accurate position data, and then compares the data with the scheduled route to obtain the deviation of the actual track point from the scheduled Route error signal, and send it to the flight control system, so that the aircraft returns to the predetermined course, and autonomous GPS navigation when completing the flight mission; when the aircraft needs to land, the more accurate GPS position data obtained by the on-board computer determines the current Compared with the scheduled glide track, the deviation is obtained, and the deviation is sent to the flight control system. The flight control system controls the flight position of the UAV, so that it can track the landing and glide route, and follow the pre-planned route safely. landing.

When the on-board GPS equipment fails, or the GPS signal is interfered and lost, the normal workflow of the above-mentioned drones will not be carried out smoothly, and the flight mission and landing process of the aircraft will be affected. Effective GPS data cannot accurately control the aircraft trajectory, let alone guide the UAV to land accurately.

The present invention is a technical solution designed to solve the above problems, and mainly includes two parts: long-distance radio guidance and short-distance laser guidance.

1. Long-distance radio guidance

In the remote radio guidance stage, after the onboard GPS fails, the ground measurement and control station uses radio to guide the aircraft to the approach window to the laser guidance window. In Figure 1, the main component of long-range radio guidance is the ground monitoring and control station. It is the ground measurement and control station that comes with the UAV. Since it needs to provide relatively accurate radio angle measurement, it is necessary to fix the measurement and control station accurately parallel or perpendicular to the runway, and perform initial calibration with the calibrated runway heading, so that the ground The GPS information of the measurement and control station meets the accuracy requirements.

Specific steps are as follows:

(1) Shield the GPS data and switch to the radio guidance mode. The ground measurement and control station will send the distance, azimuth, pitch angle and GPS latitude and longitude information from the UAV to the ground measurement and control station by radio to the flight of the UAV. Control System;

(2) The flight control system of the UAV roughly calculates the distance, azimuth, pitch angle and the GPS latitude and longitude information of the ground measurement and control station from the UAV to the ground measurement and control station, as shown in Figure 1. Longitude and latitude information, the UAV flight control system performs autonomous navigation according to the calculated longitude and latitude information until it flies into the approach window;

As shown in Figure 3, the approach window is defined as a range of 13-15 kilometers from the near end of the airport runway and a height of 500-800 meters.

The UAV completes data communication with the ground measurement and control station through radio. The ground measurement and control station has the functions of radio signal search, tracking and positioning, which can make the UAV always fly along the radio indication trajectory; the antenna of the measurement and control station has a two-axis servo system. Through the servo system The direction sensor measures the horizontal and pitch angle changes of the antenna, and then obtains the azimuth and pitch angle of the drone, and gives the deviation between the current track of the drone and the predetermined track, and at the same time, the radio signal ranging device can provide unmanned According to the position of the UAV relative to the ground measurement and control station, and then according to the pre-collected GPS position information of the ground measurement and control station, the rough positioning of the UAV can be completed. Finally, the information is transmitted to the flight control system through the wireless data transmission station to correct the UAV track and form a closed-loop control system to control the aircraft. The UAV can complete autonomous navigation without GPS and fly to the designated area through the calculated position information and the altitude information given by its own altitude sensor.

Of course, this process can also be manually navigated according to the longitude and latitude information of the drone transmitted to the ground measurement and control station until it flies to the designated area.

(3) According to the radio guidance of the ground measurement and control station, the drone flies along the direction of the runway at a fixed height and level;

In the process of long-distance radio guidance, the UAV needs to fly at a fixed altitude with a range of about 5-7km. In this process, before the aircraft reaches the laser guidance window, the aircraft must fly into the fan-shaped area of the laser scanning beam. The laser scanning device needs to be turned on and scanned during the long-range radio guidance phase.

2. Short distance laser guidance

Proximity laser guidance is from the laser guidance window to the landing stage. The equipment that needs to be utilized in short-range laser guidance includes the magnetic heading instrument on the UAV. Correct the deviation of the magnetic heading instrument on the runway in advance according to the calibrated runway heading, and use it for UAV flight and emergency landing heading control and taxiing control.

Specific steps are as follows:

(4) Enter the laser guide window, that is, the UAV flies to a position 8 to 10 kilometers away from the near end of the runway, and judge whether the laser receiver has received the laser information sent by the laser scanner. If not, go to step (5) ), otherwise go to step (6);

(5) The UAV maintains the original flight state (direction and altitude), and judges whether the distance between the UAV and the near end of the runway is less than 5 kilometers. If it is less than 5 kilometers, control the UAV to go around and return to the field. Start again from step (4);

(6) The data processor determines the current direction of the UAV and the distance between the UAV and the laser scanner according to the received laser information, and the UAV flight control system adjusts the UAV to face the UAV according to the current direction of the UAV. Fly in the direction of the center of the runway, and control the UAV to land safely on the runway according to the distance between the UAV and the laser scanner.

飞行，

角可以由飞机上的磁航向仪给出，那么就可以根据几何关系求出图中所示的θ₁和θ₂角，两激光接收器的安装距离D是已知量，再由三角关系就能求出图中所示的R，也就可以计算出激光发射器到无人机的距离S，这里无人机的高度信息由无线电高度表给出，根据勾股定理可以计算出无人机的高度角。无人机的侧偏角由β₁和β₂确定

高度角由S和无线电高度表来求出，由此可以确定无人机的方向信息(高度角，侧偏角)和位置信息(距离S，无人机的经纬度等)，其中所得的侧偏角是无人机应急着陆的所需的重要参考信息。无人机飞行控制系统根据无人机当前侧偏角调整无人机以正对跑道中心的方向飞行，将当前高度角与预先设定的高度角(4度一般)进行比对，调整无人机的飞行高度，控制高度差，使其跟踪预先设定的降落下划线，并根据无人机与激光扫描器之间的距离控制无人机在跑道上安全着陆。Here, the laser scanner emits a pulsed laser beam at a fixed frequency, and encodes the pulsed laser beam, that is, the laser pulse information at different scanning angles is different, so that the laser received by the laser receiver can be determined. The orientation information carried by the beam. β ₁ and β ₂ in Figure 4 are the angles between the two laser receivers (A1, A2) and the laser scanner and the runway centerline. At this time, it is assumed that the UAV and the vertical line L formed by the vertical runway centerline angle

flight,

The angle can be given by the magnetic heading instrument on the aircraft, then the θ ₁ and θ ₂ angles shown in the figure can be obtained according to the geometric relationship, the installation distance D of the two laser receivers is a known quantity, and then the trigonometric relationship can be obtained If R shown in the figure can be calculated, the distance S from the laser transmitter to the UAV can also be calculated. Here, the height information of the UAV is given by the radio altimeter. According to the Pythagorean Theorem, the distance S of the UAV can be calculated. height angle. The side slip angle of the drone is determined by β ₁ and β ₂

The altitude angle is obtained by S and the radio altimeter, so that the direction information (altitude angle, side slip angle) and position information (distance S, longitude and latitude of the UAV, etc.) of the UAV can be determined. Angle is an important reference information required for UAV emergency landing. The UAV flight control system adjusts the UAV to fly in the direction facing the center of the runway according to the current side slip angle of the UAV, compares the current altitude angle with the preset altitude angle (generally 4 degrees), and adjusts the drone The flight height of the drone is controlled, and the altitude difference is controlled so that it can track the pre-set landing underline, and the drone can be controlled to land safely on the runway according to the distance between the drone and the laser scanner.

Parts not described in detail in the present invention belong to the common knowledge of those skilled in the art.

Claims (1)

1. unmanned plane emergency landing method based on radio and laser aiming is characterized in that: the equipment that method is relied on comprises laser scanner, laser pickoff and data processor; Laser scanner is arranged on the end of runway one end, scanning center's line up with runway center line, send the sheet laser beam with positive and negative 5 degree to the sweep limit of positive and negative 10 degree, two laser pickoffs are arranged on two ends of unmanned plane wing, be connected with data processor by cable, data processor is arranged in the equipment compartment of unmanned plane; When the flight control system of unmanned plane judged that the gps data that receives breaks down, the emergency landing method step was as follows:

(1) mask gps data, change the radio bootmode over to, ground control station is sent to unmanned plane the flight control system of unmanned plane to the GPS latitude and longitude information of distance, position angle, the angle of pitch and the ground control station of ground control station by radio;

(2) flight control system of unmanned plane is according to the GPS latitude and longitude information of the unmanned plane that receives to distance, position angle, the angle of pitch and the ground control station of ground control station, extrapolate roughly the latitude and longitude information of unmanned plane, UAV Flight Control System is carried out independent navigation according to the latitude and longitude information of extrapolating, until fly into the window of marching into the arena:

(3) unmanned plane is according to the radio guiding of ground control station, and Ding Gaoping flies along the runway center line marking direction;

(4) enter the laser aiming window, be unmanned plane during flying to the position apart from 8 to 10 kilometers of runway proximal heads, judge whether laser pickoff receives the laser intelligence that laser scanner sends, if do not receive, turn step (5), otherwise turn step (6);

(5) unmanned plane is kept former state of flight, continue to judge whether laser pickoff receives the laser intelligence that laser scanner sends in this process, meanwhile flight control system judge unmanned plane apart from the distance of runway proximal head whether lower than 5 kilometers, if lower than 5 kilometers, control unmanned plane and go around and give an encore, restart from step (4);

(6) data processor is determined direction that unmanned plane is current and the distance between unmanned plane and laser scanner according to the laser intelligence that receives, UAV Flight Control System direction current according to unmanned plane adjusted unmanned plane with the direction flight over against the runway center, and controls unmanned plane safe landing on runway according to the distance between unmanned plane and laser scanner.

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