2024年4月28日发(作者：)

Key to the development of four-rotors micro air vehicle

technology

To date, micro d experimental study on the basic theory of rotary wing

aircraft and have made more progress, but to really mature and practical, also

faces a number of key technical challenges.

1. Optimal design

Overall design of rotary-wing aircraft when small, need to be guided by the

following principles: light weight, small size, high speed, low power

consumption and costs. But these principles there are constraints and

conflicting with each other, such as: vehicle weights are the same, is inversely

proportional to its size and speed, low energy consumption. Therefore, when

the overall design of miniature four-rotor aircraft, first select the appropriate

body material based on performance and price, as much as possible to reduce

the weight of aircraft; second, the need to take into account factors such as

weight, size, speed and energy consumption, ensuring the realization of

design optimization.

2. The power and energy

Power unit includes: rotor, micro DC motor, gear reducer, photoelectric

encoder and motor drive module, the energy provided by onboard batteries.

Four-rotors micro air vehicle's weight is a major factor affecting their size and

weight of the power and energy devices accounted for a large share of the

weight of the entire body. For the OS4 II, the proportion is as high as 75%.

Therefore, development of lighter, more efficient power and energy devices is

further miniaturized four key to rotary wing aircraft.

The other hand, the lifting occurs with a power unit, most airborne energy

consumption. For example, OS4 II power 91% power consumption. To

increase the efficiency of aircraft, the key is to improve the efficiency of the

power plant. In addition to maximize transmission efficiency, you must also

select the motor and reduction ratios, taking into account the maximum

efficiency and maximum power output under the premise of two indicators,

electric operating point within the recommended run area.

3. The establishment of mathematical model

In order to achieve effective control of four-rotors micro air vehicles, must

be established accurately under various flight model. But during the flight, it not

only accompanied by a variety of physical effects (aerodynamic, gravity,

gyroscopic effect and rotor moment of inertia, also is vulnerable to

disturbances in the external environment, such as air. Therefore, it is difficult to

establish an effective, reliable dynamic model. In addition, the use of rotary

wing, small size, light weight, easy to shape, it is difficult to obtain accurate

aerodynamic performance parameters, and also directly affects the accuracy

of the model.

Establishment of mathematical model of four-rotor MAV, must also be

studied and resolved problems rotor under low Reynolds number

aerodynamics. Aerodynamics of micro air vehicle with conventional aircraft is

very different, many aerodynamic theory and analysis tools are not currently

applied, requires the development of new theories and research techniques.

4. Flight control

Four-rotors micro air vehicle is a six degrees of freedom (location and

attitude) and 4 control input (rotor speed) of underactuated system

(Underactuated System), have more than one variable, linear, strongly

coupled and interfere with sensitive features, makes it very difficult to design of

flight control system. In addition, the controller model accuracy and precision

of the sensor performance will also be affected.

Attitude control is the key to the entire flight control, because four-rotors

micro air vehicle's attitude and position a direct coupling (roll pitch p directly

causes the body to move around before and after p), if you can precisely

control the spacecraft attitude, then the control law is sufficient to achieve its

position and velocity PID control. International study to focus on with attitude

control design and validation, results show that although the simulation for

nonlinear control law to obtain good results, but has a strong dependence on

model accuracy, its actual effect rather than PID control. Therefore, developed

to control the spacecraft attitude, also has strong anti-jamming and

environment-Adaptive attitude control of a tiny four-rotary wing aircraft flight

control system of priorities.

5. Positioning, navigation and communication

Miniature four-rotor aircraft is primarily intended for near-surface

environments, such as urban areas, forests, and interior of the tunnel.

However, there are also aspects of positioning, navigation and communication.

One hand, in near-surface environments, GPS does not work often requires

integrated inertial navigation, optics, acoustics, radar and terrain-matching

technology, development of a reliable and accurate positioning and navigation

technology, on the other, near-surface environment, terrain, sources of

interference and current communication technology reliability, security and

robustness of application still cannot meet the actual demand. Therefore,

development of small volume, light weight, low power consumption, reliability

and anti-jamming communication chain in four-rotors micro air vehicle

technology (in particular the multi-aircraft coordination control technology)

development, are crucial.

微小型四旋翼飞行器发展的关键技术

迄今为止，微小型四旋翼飞行器基础理论与实验研究已取得较大进展，但要

真正走向成熟与实用，还面临着诸多关键技术的挑战。

1.最优化总体设计

进行微小型四旋翼飞行器总体设计时，需要遵循以下原则：重量轻、尺寸小、

速度快、能耗和成本低。但这几项原则相互之间存在着制约与矛盾，例如：飞行

器重量相同时，其尺寸与速度、能耗成反比。因此，进行微小型四旋翼飞行器总

体设计时，首先要根据性能和价格选择合适的机构材料，尽可能地减轻飞行器重

量；其次，需要综合考虑重量、尺寸、飞行速度和能耗等因素，确保实现总体设

计的最优化。

2.动力与能源

动力装置包括：旋翼、微型直流电机、减速箱、光电码盘和电机驱动模块，

能量由机载电池提供。微小型四旋翼飞行器的重量是影响其尺寸的主要因素，而

动力与能源装置的重量在整个机体重量中占了很大比例。对于OS4 II,该比例就

高达75%。因此，研制更轻、更高效的动力与能源装置是进一步微小型化四旋翼

飞行器的关键。

另一方面，动力装置产生升力时，消耗了绝大部分机载能量。例如，OS4 II

的电能有91%被动力装置消耗。要提高飞行器的效率，关键在于提高动力装置的

效率。除尽量提高机械传动效率外，还必须选择合适的电机与减速比，在兼顾最

大效率和最大输出功率两项指标的前提下，将电机工作点配置在推荐运行区域

内。

3.数学模型的建立

为实现对微小型四旋翼飞行器的有效控制，必须准确建立其在各种飞行状态

下的数学模型。但是飞行过程中，它不仅同时受到多种物理效应的作用(空气动

力、重力、陀螺效应和旋翼惯量矩等，还很容易受到气流等外部环境的干扰。因

此，很难建立有效、可靠的动力学模型。此外，所使用的旋翼尺寸小、质量轻、

易变形，很难获得准确的气动性能参数，也将直接影响模型的准确性。

建立四旋翼MAV数学模型时，还必须深入研究和解决低雷诺数条件下旋翼空

气动力学问题。微型飞行器空气动力学特性与常规飞行器有很大的不同，当前许

多空气动力学理论和分析工具均不适用，需要发展新的理论和研究手段。

4.飞行控制

微小型四旋翼飞行器是一个具有六自由度(位置与姿态)和4个控制输入(旋

翼转速)的欠驱动系统(Underactuated System)，具有多变量、非线性、强耦合

和干扰敏感的特性，使得飞行控制系统的设计变得非常困难。此外，控制器性能

还将受到模型准确性和传感器精度的影响。

姿态控制是整个飞行控制的关键，因为微小型四旋翼飞行器的姿态与位置存

在直接耦合关系(俯仰P横滚直接引起机体向前后P左右移动)，如果能精确控制

飞行器姿态，则采用PID控制律就足以实现其位置与速度控制。国际相关研究都

着重进行了姿态控制器的设计与验证，结果表明：尽管采用非线性控制律能够获

得很好的仿真效果，但由于对模型准确性有很强的依赖，其实际控制效果反而不

如PID。因此，研制既能精确控制飞行器姿态，又具有较强抗干扰和环境自适应

能力的姿态控制器是微小型四旋翼飞行器飞行控制系统研究的当务之急。

5.定位、导航与通信

微小型四旋翼飞行器主要面向近地面环境，比如：城区、森林、隧道和室内

等。但是，目前还存在定位、导航与通信方面的问题。一方面，在近地面环境中，

GPS常常不能正常工作，需要综合惯导、光学、声学、雷达和地形匹配等技术，

开发可靠而精确的定位与导航技术；另一方面,近地面环境地形复杂，干扰源多，

当前通信链技术的可靠性、安全性和抗干扰性还不能满足实际应用的需求。因此，

研制体积小、重量轻、功耗低、稳定可靠和抗干扰的通信链对微小型四旋翼飞行

器技术(尤其是多飞行器协同控制技术)的发展而言，是十分关键的。