With the increasing number of UAV products, the competitiveness between markets is gradually improving. Therefore, this project has developed a multi-rotor UAV, which is more suitable for products in industrial control, automation equipment and other fields. This product not only has a reasonable positioning, but also has some differences with other products. Mission system refers to unmanned multi-rotor mission with advanced intelligent equipment data link, which has high energy utilization efficiency and load transportation performance, and is incomparable to other UAV products in technology. Making a reasonable market plan will bring certain economic benefits to enterprises.
1 Overview of the definition of multi-rotor UAV
The UAV we often talk about is an unmanned aerial vehicle system, which mainly uses wireless intelligent remote control equipment and its own control program device to control unmanned aerial vehicles. Among them, the generalized UAV includes the narrow UAV and airplane model.
A multi-rotor aircraft mainly consists of a power system, a main body and a control system, wherein the power system comprises a motor, a power supply, an electronic governor and blades; The main body part comprises a frame, a tripod and a tripod head; The control system comprises a manual control consisting of a remote control receiver and a remote controller; Ground station, and flight controller composed of main control, GPS, IMU, electronic gyro and LED display screen. The quadrotor aircraft is an underactuated system with four inputs and six outputs. Through PID, robust, fuzzy, nonlinear and adaptive neural network control. In recent years, the research trends of the control function of the system are large load, autonomous flight, intelligent sensor technology, autonomous control technology, multi-aircraft formation cooperative control technology, miniaturization and so on. Some key technologies are the establishment of mathematical model, energy supply system, flight control algorithm, autonomous navigation and intelligent flight.
2 improvement and development stages of control system
The control system of multi-rotor UAV was originally composed of inertial navigation system and MEMS technology, forming the EMES inertial navigation system. After the study of EMES denoising, the noise problem of sensor data is effectively reduced. Finally, through the research and application of constant speed single chip microcomputer and nonlinear system structure, a multi-rotor UAV automatic control aircraft with relatively stable performance was manufactured in 2005. The evaluation of its aircraft can be analyzed from the aspects of safety, load, flexibility, maintainability, expansibility and stability. It has the characteristics of small size, light weight, low noise, strong concealment, multi-space platform use, vertical take-off and landing, low flying height, strong maneuverability and strong task execution ability. Structurally, it not only has the characteristics of high safety, convenient disassembly and maintenance, small propeller, low cost and flexible control.
3 technical principle
3. 1 system composition
The overall technical scheme of the unmanned multi-rotor mission system is shown in figure 1. As shown in the figure, the unmanned multi-rotor mission system consists of unmanned aerial vehicles and ground workstations. UAV consists of multi-rotor UAV and mission load; The ground workstation consists of data link communication unit, industrial control computer and flight control rocker.
3.2 System technical principle
3.2. 1 Multi-rotor UAV realizes stable flight attitude control and maintenance by fine-tuning propeller thrust. Through the comparison of multi-rotor UAV, conventional helicopter and fixed-wing aircraft, it can be clearly seen that multi-rotor UAV has the advantage of multi-energy in mission flight, so as to better execute and complete the mission, improve the defects of maintaining flight attitude and consuming a lot of energy, thus better ensuring its energy utilization rate and directly improving its endurance time and load transportation performance; The structure has been simplified a lot, and the transmission mechanism has been omitted, which greatly reduces its running noise, failure probability and maintenance cost.
3.2.2 The communication between UAV and ground workstation is connected by equipment data link, which plays the role of communication intermediary and is also an important bridge between UAV and ground workstation to realize ground-air information exchange. In the past, UAV was just an ordinary point-to-point communication, which was used for the conversion and connection of ground-to-air information. Due to the influence of signal transmission distance, its performance is seriously affected, and only some simple remote control data signals can be transmitted.
However, in this project, the research of unmanned multi-rotor mission system is based on the data link protocol MAVLink, which is reasonably embedded in the control core and the ARM platform of ground data link, effectively improving the problems existing in the previous low-altitude information transmission link, unifying the five remote functions of telemetry, telecommunications, remote control, remote adjustment and remote viewing, ensuring the barrier-free communication between UAV and ground workstation, and fundamentally solving the data communication problem between UAV and ground workstation. 0.5 remote control; Among them, telemetry refers to the measurement of analog quantities such as voltage, current, power, pressure and temperature in the distance; Among them, remote communication refers to monitoring the working and running status of electrical switches, equipment and mechanical equipment in the distance; Remote control refers to the control and protection of the working state of remote electrical equipment and electrical mechanization devices; Remote adjustment refers to setting and adjusting the working parameters and standard process of the remotely controlled equipment; Remote viewing refers to monitoring and recording the safe operation state of remote equipment.
3.2.3 The traditional UAV needs to control its flight attitude by manual operation of the remote controller in the flight process, which reflects its defects such as imperfect automation program and monotonous function. The research of UAV in this project, through the matching of mission planning software in the ground workstation, effectively improved the shortcomings of single function in the past and directly increased its functionality. Among them, the mission planning software, combined with GoogleMap high-speed API interface, can realize the simple planning of UAV flight route on the three-dimensional map, and can also start its route to realize automatic cruise, mission execution, return flight and other operations.
4 technical points and innovations
4. 1 technical points:
4. 1. 1 ground-air information data communication.
MAVLink, an advanced intelligent equipment data link protocol, can effectively integrate all its data, all of which can be summarized in the data link, integrating five teleoperations, effectively reducing the problems existing in various communication systems and communication modules, improving communication efficiency and ensuring the effective play of communication functions.
4. 1.2 solving the problem of flight attitude control
The application of embedded operating system on ARM processor platform, coupled with advanced algorithms such as gyroscope and Kalman filter, can better ensure the increase of control system functions. In addition, it not only realizes unmanned flight, but also effectively reduces energy consumption and improves energy utilization in flight control.
4. Extension of1.3 in the field of industrial control
Based on the construction and research idea of multi-load in the same vehicle, this project aims to design the task load with the same data, electrical and mechanical interfaces for the same type of multi-rotor aircraft, realize rapid load replacement, make the switching and connection of flight tasks good and stable, ensure the practicability of the system and reduce the task execution cost.
4. 1.4 Enhance the function of the ground workstation
Through C/S architecture, C# language,. Net platform, three-dimensional GoogleMap, SQL database, ground task planning software and data analysis software, the functions of ground workstations, and the degree of automation and intelligence can better operate for users and bring more convenience.
4.2 Technical Innovation of the Project
4.2. 1 In UAV and ground station, data link MAVLink is implanted, and the overall system function is improved, effectively realizing the overall unification of five remote stations.
4.2.2 Kalman filter, quaternion algorithm and embedded ARM platform can effectively control its flight attitude.
4.2.3 The research on the idea of "one plane+multiple loads" has realized the effective conversion of UAV to mission execution mode.
4.2.4 At the same time, the application of ground task planning software and analysis data analysis software has improved the control function and intelligence of the system.
5 abstract
To sum up, through the analysis of unmanned multi-rotor mission system, it is found that there are still many imperfections in the research in this field in China. Compared with previous unmanned aerial vehicles, this project has realized the unification of telemetry, remote communication, remote control, remote adjustment and remote viewing through C/S architecture, C# language, advanced intelligent equipment data link and analysis data analysis software. In the aspect of task execution mode, flexible conversion is realized; In the aspect of flight attitude, intelligent control is realized; On the basis of the existing multi-rotor flight control technology, it effectively avoids its previous defects, and provides autonomous flight control software programming for flight control tasks, effectively realizing intelligent flight with autonomous navigation in flight.
;