基于自适应遗传算法的小型无人旋翼机系统辨识方法

提出一种基于自适应遗传算法的小型无人旋翼飞行器系统辨识方法.通过机载传感器设备,系统采集小型无人旋翼机的输入信号(舵机的控制信号)和输出信号(飞行器的姿态及速度等信息);经过数据预处理后,利用自适应遗传算法构建小型无人旋翼飞行器高精度动力学模型,并通过仿真和实验对模型的自效性进行验证.实验表明,基于本文提出的动态模型,...     

基于PIC的微小倾转旋翼机辨识建模设计

文中的研究目的是建立倾转旋翼飞机的模型,从而解决倾转旋翼飞机的控制问题.介绍了基于PIC18F单片机和微机械(MEMS)传感器的微小倾转旋翼机纵向通道辨识建模系统设计.其中系统设计采用了实验建模的方法,利用PIC单片机的CCP模块实时捕捉遥控输入信号,利用MEMS传感器实时采集飞行姿态信号,并在MATIAB/SIMULINK环境下进行了仿真.仿真结果表明系统能够准确采集输入和输出数据.通过精密低速转台测速实验,证明该系统工作稳定,精度可靠.实时性较好.     

基于LabVIEW的四旋翼飞行器姿态监测系统设计

姿态监测是四旋翼飞行器实现正常飞行的主要因素之一,飞控手操控飞行但无法精准地获取实时姿态数据,存在一定的误差且准确性较低;针对以上问题,系统设计采用STM32F103RBT6单片机和MPU9250传感器采集四旋翼飞行器飞行过程中的飞行高度、飞行速度、滚转角以及俯仰角,并将数据传输给上位机LabVIEW软件平台;在虚拟软件平台对四旋翼飞行器的姿态信息进行显示、存储、报警及回放等功能;测试结果表明,姿态监测系统可以实现数据可视化,采集数据的绝对偏差值小于0.5%,提高了四旋翼飞行器姿态监测的准确性,满足了控制小型四旋翼无人机的实际需要。     

在线滚动优化下的无人自转旋翼机自动起飞控制

自转式旋翼机的旋翼是一种无动力升力装置,旋翼需来流吹动旋转而获得升力,因此自转旋翼机大多采用滑跑方式起飞.由于自转旋翼机具有特殊的气动特性和操纵特点,基于姿态控制的滑跑起飞策略不能直接用于无人自转旋翼机的起飞控制.本文针对无人自转旋翼机所特有的旋翼桨盘迎角、地速和气动升力之间相互约束和制约的特点,在分析无人自转旋翼起飞阶段动力学特性的基础上,提出了一种基于在线滚动优化理论的无人自转旋翼机起飞控制方法.通过预测未来有限时间内无人自转旋翼机的运动状态,得到起飞过程的最优控制序列,能够维持无人自转旋翼机在起飞过程中始终具有足够的升力和合适的爬升角.通过仿真验证和分析,证明了本文所提出的控制算法能够实现无人自转旋翼机的平稳起飞.     

基于DSP的无人飞行器数据采集系统的设计

现有无人飞行器数据采集均由机载计算机主处理器完成,效率较低,为了提高效率,解决数据采集的可靠性、实时性及精度等问题,设计了一种基于DSP处理器的数据采集系统,该数据采集系统能够对54路模拟量进行巡回采集,给出了系统的软硬件实现方法,在数据采集结束后,系统通过双端口RAM与机载计算机主处理器进行数据传递;为了提高DSP片内ADC的采集精度,()了片内ADC的软硬件校正方法;实验证明,该系统具有较高的可靠性,能够满足飞行控制系统对传感器数据采集的实时性及精度要求.     

一种小型无人直升机捷联式组合导航系统设计

在基于小型无人直升机空中作业中,不仅需要导航系统提供的精确数据进行飞行控制,还需安装其它设备完成作业.为了减少小型无人直升机的负重,增加飞行时间,机载的导航系统需要高精度、低功耗、微型化的设计,采用微电子机械系统传感器的捷联式惯性导航系统满足了这些要求.然而惯性传感器的漂移会使捷联系统的数学解算产生误差累计,因而需要对惯性导航系统数据进行实时修正.本文设计了一种GPS修正的组合导航系统算法,应用卡尔曼滤波技术,对组合系统的多传感器进行数据融合,既保持了捷联惯导系统的自主性,又消除了累积误差,提高了组合系统的可靠性.上述系统通过在小型无人直升机飞行控制系统中的使用,验证了系统算法的有效性.     

小型四旋翼飞行器试验平台设计

为了实现小型四旋翼飞行器的自主导航,进行自主飞行的相关试验,并为控制器设计和微小型导航系统性能试验等研究工作提供实体验证平台,开展了小型四旋翼飞行器系统的设计.完成了系统的模块化设计,进行硬件电路设计和调试以及平台的搭建,实现导航、控制、通信等功能模块的集成.设计PC机监控软件,完成了基于USB HID协议的操纵杆数据读取,对操纵杆遥控控制模式下小型四旋翼飞行器进行实时监测,实现人机交互、控制方式选择、对飞行姿态和路线的设置、飞行器导航参数的显示等功能,开展了飞行试验,验证所设计平台各功能模块的可行性.     

四旋翼无人飞行器姿态数据采集处理系统

针对机械振动等因素产生的噪声对加速度传感器测量姿态数据的影响,增加了陀螺仪并运用卡尔曼滤波对加速度传感器和陀螺仪的数据进行融合处理;与以往均值和中值等滤波姿态算法相比,采用卡尔曼滤波算法能够获得可靠、稳定的姿态数据,为四旋翼无人飞行器稳定飞行提供有效保障;介绍了姿态传感器和采集处理系统硬件结构及软件实现,运用图形化编程语言LabView实现对四旋翼无人飞行器实时姿态曲线显示、姿态数据存储、回放等功能;经测试,能有效的降低机械振动等噪声对飞行器姿态测量的影响,提高姿态数据估计的精度,达到了预期的目标。     

基于预测误差法小型无人直升机系统辨识

小型无人直升机是一个复杂的非线性系统.为了真正实现小型无人直升机的自主飞行,须对其进行数学建模.本文重点分析了Raptor90小型无人直升机悬停时横、纵向通道的输入输出关系,通过严格推导得到横、纵向通道通的参数化模型.通过试验采集得到输入输出数据,利用基于预测误差法的输出误差模型进行系统辨识.模型预测数据与实际飞行实验室数据的比较表明,所建模型很好的反映了小型无人直升机在悬停状态下的动力学特性,可在该状态下基于此模型进行飞行控制器的设计.     

旋翼微小型无人机地面站系统的设计与实现

针对旋翼机的控制复杂性,设计一套面向旋翼式微小型无人机的地面控制站系统。利用该系统可进行航迹设定和任务规划,存储和回放飞机航行记录,接收航拍图像,并通过对旋翼式无人机虚拟模型和视频图像的融合处理,实时显示飞机飞行姿态、位置及运行状态,实现旋翼式微小型无人机的超视距遥控,具有直观、形象的良好操控性能。     

四旋翼飞行器控制系统设计

四旋翼飞行器姿态控制是四旋翼飞行器控制系统的核心. 通过分析四旋翼飞行器的飞行原理,模型建立,设计了四旋翼飞行器的姿态控制系统;在该系统中采用STM32系列处理器作为主控芯片,MPU6050三轴加速度集和三轴陀螺仪惯性测量单元、磁力计等传感器用于姿态信息检测. 本文中传感器使用结构简单的数字接口对数据进行交换,运用模块化的思想对系统进行设计. 使用PID控制算法进行姿态角的闭环控制,最终实验结果表明,在实验平台上四旋翼飞行器飞行效果稳定,系统满足四旋翼飞行器飞行姿态控制的要求.     

Adaptive Neural Network Control of Small Unmanned Aerial Rotorcraft

This paper proposes an online learning adaptive neural network for small unmanned aerial rotorcraft to improve control performance during flight. Based on state error information, the weight matrix of the adaptive neural network can be updated on line by using lyapunov function. Therefore, no prior training data is needed for the training of the adaptive neural network. Combined with feedback control, the adaptive neural network can construct the map between the state error information and disturbances to compensate for system disturbances. The effectiveness of the proposed method is validated by a series of simulations and flight tests. Compared with feedback control method, the adaptive neural network control method can estimate and eliminate disturbances quickly to yield a good tracking performance.     

Robust Model Predictive Flight Control of Unmanned Rotorcrafts

This paper addresses the problem of robust flight control of unmanned rotorcrafts, by proposing and experimentally evaluating a real–time robust model predictive control scheme in various challenging conditions, aiming to capture the demanding nature of the potential requirements for their efficient and safe integration in real–life operations. The control derivation process is based on state space representations applicable in most rotorcraft configurations and incorporate the effects of external disturbances. Exploiting this modeling approach, two different unmanned rotorcraft configurations are presented and experimentally utilized. The formulated control strategy consists of a receding horizon scheme, the optimization process of which employs the minimum peak performance measure, while incorporating and accounting for the modeled dynamics and input and state constraints. This strategy aims to ensure the minimum possible deviation subject to the worst–case disturbance, while robustly respecting and satisfying the physical limitations of the system, or a set of mission-related requirements, as encoded in the constraints. The proposed framework is further augmented in order to provide obstacle avoidance capabilities into a unified scheme. Multiparametric methods were utilized in order to provide an explicit solution to the controller computation optimization problem, therefore allowing for fast real–time execution and seamless integration into any digital avionics system. The efficiency of the proposed strategy is validated via several experimental case studies on the two unmanned rotorcraft platforms. The experiments set consists of: trajectory tracking subject to atmospheric disturbances, slung load operations, fast highly disturbed maneuvers, collisions handling, as well as avoidance of known obstacles.     

Design and Implementation of a Flight Control System for an Unmanned Rotorcraft using RPT Control Approach

In this paper, we apply a so‐called robust and perfect tracking (RPT) control technique to the design and implementation of the flight control system of a miniature unmanned rotorcraft, named HeLion. To make the presented work self‐contained, we will first outline some background knowledge, including mainly the nonlinear flight dynamics model and the inner‐loop flight control system design. Next, the highlight of this paper, that is, the outer‐loop flight control system design procedure using RPT control technique, will be detailed. Generally speaking, RPT control technique aims to design a controller such that (i) the resulting closed‐loop system is asymptotically stable, and (ii) the controlled output almost perfectly tracks a given reference signal in the presence of any initial conditions and external disturbances. Since it makes use of all possible information including the system measurement output and the command reference signal together with all its derivatives (if available) for control, RPT control technique is particularly useful for the outer‐loop layer of an unmanned aircraft. Both simulation and flight‐test results will be presented and analyzed at the end of this paper, and the efficiency of the RPT control approach will be evaluated comprehensively.     

An adaptive vision-based autopilot for mini flying machines guidance,navigation and control

The design of reliable navigation and control systems for Unmanned Aerial Vehicles (UAVs) based only on visual cues and inertial data has many unsolved challenging problems, ranging from hardware and software development to pure control-theoretical issues. This paper addresses these issues by developing and implementing an adaptive vision-based autopilot for navigation and control of small and mini rotorcraft UAVs. The proposed autopilot includes a Visual Odometer (VO) for navigation in GPS-denied environments and a nonlinear control system for flight control and target tracking. The VO estimates the rotorcraft ego-motion by identifying and tracking visual features in the environment, using a single camera mounted on-board the vehicle. The VO has been augmented by an adaptive mechanism that fuses optic flow and inertial measurements to determine the range and to recover the 3D position and velocity of the vehicle. The adaptive VO pose estimates are then exploited by a nonlinear hierarchical controller for achieving various navigational tasks such as take-off, landing, hovering, trajectory tracking, target tracking, etc. Furthermore, the asymptotic stability of the entire closed-loop system has been established using systems in cascade and adaptive control theories. Experimental flight test data over various ranges of the flight envelope illustrate that the proposed vision-based autopilot performs well and allows a mini rotorcraft UAV to achieve autonomously advanced flight behaviours by using vision.     

基于AFKF的多旋翼无人机组合导航技术研究

目前旋翼无人机组合导航系统大都使用扩展卡尔曼滤波算法,然而由于导航系统建模误差和传感器测量精度的影响,导航信息解算误差较大。为了改善旋翼无人机的飞行控制效果,应用自适应渐消卡尔曼滤波（Adaptive fading Kalman filter,AFKF）进行旋翼无人机组合导航解算,算法通过实时计算遗忘因子,对过去的数据权重进行削减,以提高扩展卡尔曼滤波算法的自适应能力。应用旋翼无人机真实飞行数据进行仿真,仿真结果表明,自适应渐消卡尔曼滤波算法能够有效抑制建模误差,弥补传感器测量精度不足,改善旋翼无人机组合导航解算结果。     

Autonomous feature following for visual surveillance using a small unmanned aerial vehicle with gimbaled camera system

This paper represents the development of feature following control and distributed navigation algorithms for visual surveillance using a small unmanned aerial vehicle equipped with a low-cost imaging sensor unit. An efficient map-based feature generation and following control algorithm is developed to make an onboard imaging sensor to track a target. An efficient navigation system is also designed for real-time position and velocity estimates of the unmanned aircraft, which is used as inputs for the path following controller. The performance of the proposed autonomous path following capability with a stabilized gimbaled camera onboard a small unmanned aerial robot is demonstrated through flight tests with application to target tracking for real-time visual surveillance.     

Robust attitude tracking control of small-scale unmanned helicopter

Robust attitude control problem for small-scale unmanned helicopters is investigated to improve attitude control performances of roll and pitch channels under both small and large amplitude manoeuvre flight conditions. The model of the roll or pitch angular dynamics is regarded as a nominal single-input single-output linear system with equivalent disturbances which contain nonlinear uncertainties, coupling-effects, parameter perturbations, and external disturbances. Based on the signal compensation method, a robust controller is designed with two parts: a proportional-derivative controller and a robust compensator. The designed controller is linear and time-invariant, so it can be easily realised. The robust properties of the closed-loop system are proven. According to the ADS-33E-PRF military rotorcraft standard, the controller can achieve top control performances. Experimental results demonstrate the effectiveness of the proposed control strategy.     

旋翼无人机六自由度飞行测试系统设计与应用

为安全、精准、高效地解决旋翼无人机实际飞行测试环节的数据依据问题,从被测对象的运动约束及测试需求出发,设计被动悬挂结构的六自由度运动机构,解析需要检测的四个关键参数,给出基于绝对编码的信号检测方案,形成了一种用于旋翼无人机整机飞行测试的全通道运动、多参数检测的实验系统。针对测试系统传感数据进行校对实验,验证了数据测试的有效性。与典型下端球铰链连接支撑方式的三通道检测装置进行了相同条件下的应用对比测试,验证了该测试系统在初始静稳定及抑制震荡方面的优越性。