无人机全天时航空成像侦察系统建模与仿真

航空成像侦察是获取战术情报的重要途径。设计的全天时可见光航空相机成像侦察系统参照无人机各种飞行环境,基于无人机数学模型、可见光相机成像几何模型和大气辐射传输模型,实现航空相机在无人机运动参数、航空相机参数、大气环境参数变化情况下的成像侦察仿真。该系统由仿真参数初始化、数字地图加载、相机成像仿真、大气辐射传输仿真、无人机半物理仿真、图像仿真与报告输出六个模块组成。通过大量实验测试表明本系统模型有很高的逼真度和有效性,同时,可根据系统仿真报告对系统模型进行性能评估与改进。本系统的参数优化功能可指导和论证无人机航空相机成像侦察装备的研制工作。     

航空相机检测系统软件设计

为了检测航空相机工作是否正常,并可对有故障相机进行故障诊断,该文设计了一套自动测试软件系统。该系统能模拟飞机的任务管理系统与相机以ARINC429总线传输方式传输数据,并按相机记录信息的要求,提供时间、地速、高度等信息,以便控制相机的工作参数并记录相关信息,完成对航空相机性能的测试。     

基于虚拟仪器航空相机故障诊断系统设计

为了检测航空相机工作是否正常,并可对有故障相机进行故障诊断,该文采用虚拟仪器技术设计了一套由工控机进行统一管理,适时对数据进行采集、保存和处理的故障诊断系统。该系统能模拟飞机的任务管理系统与相机以ARINC429总线传输方式传输数据,并按相机记录信息的要求,提供照相张数、时间、地速、高度等信息,以便控制相机的工作参数并记录相关信息,完成对航空相机性能的测试。     

精品秀

Polaroid SC1630相机 宝丽来在CES 2012上展出的智能相机，它的拍照性能在卡片机中只能算是一般，独特之处在于搭载了Android系统，可以在拍照之余上网、发邮件、听音乐、玩游戏。     

航空相机检测系统可靠性研究

航空相机检测系统是为航空相机配备的专用检测系统,利用该检测系统能够确定故障发生在哪一个电路板上,以便使用备用电路板,使相机正常工作。因此,对航空相机检测系统进行可靠性研究,保证航空相机检测系统的可靠性是十分必要的。针对航空相机检测系统的组成,进行了系统可靠性分析和可靠性指标分配,保证了可靠性设计的要求。     

航空发动机二自由度鲁棒控制器设计与验证

为了克服传统单自由度控制算法无法兼顾系统的性能和鲁棒性要求的缺陷,将二自由度和H∞控制相结合,引入二自由度H∞回路成形控制方法对某型涡扇发动机进行控制器设计;同时为了保证被控对象的输出在稳态下能较好地跟踪参考模型的输出,引入一个常数矩阵对控制回路进行了变形;为更充分对控制器性能进行验证,在设计的航空发动机数控系统实时仿真平台上进行了仿真,证实了所设计的鲁棒控制器在航空发动机控制上具有良好的性能。     

航空相机电源板故障诊断

由于载机条件、自身情况、环境条件和使用维护等原因航空相机总是会出故障,要排除故障首要解决的是检测出故障的所在。航空相机由许多块电路板组成,其内部结构十分复杂,必须对其进行从总体到元器件的逐一检测。在实际工作中,电源故障可以引起很多其他的故障。电源是电子仪器工作的基本部件,一旦发生故障,就会导致整台仪器瘫痪。本文在电路检测航空相机的工作原理的基础上,运用小波-神经网络分析方法,对电源板检测电路进行实时检测。该检测系统可以快速有效地检测航空相机电源板的故障并对其进行性能分析,减少了排障时间。     

基于LMI的滑模控制在航空发动机中的应用

针对航空发动机运行过程中存在不确定性和稳定性问题,运用状态空间模型理论与线性矩阵不等式LMI相结合的方法设计了控制器,改善了航空发动机的控制性能。以某型涡扇发动机为控制对象,基于LMI对普通终端滑模变结构控制进行了优化设计,在滑模超平面设计中引入了动态补偿器,采用改进的幂次趋近律,对该动态系统进行了性能仿真验证。结果表明,本文提出的方法较之普通终端滑模变结构控制对系统性能有较大改善,不仅使系统主供油量变化率、尾喷口面积变化率等的控制更为平稳,且保证了系统鲁棒性和稳定性。     

航空发动机全飞行包线鲁棒控制器设计研究

对全飞行包线内的发动机控制问题展开研究,分析了包线的划分和标称点的确定问题,提出了根据发动机进口参数的相对变化指标对飞行包线进行划分的方法.同时将二自由度H∞鲁棒控制方法引入航空推进系统的控制器设计中,克服了传统鲁棒控制器无法兼顾系统的性能和鲁棒性要求的缺陷.最后在设计的航空发动机数控系统快速原型化实时仿真平台上进行了仿真,证实了所提出的全包线划分方法的正确性和所设计的增益调度鲁棒控制器在某型航空发动机全包线控制上的良好性能.     

自适应模糊与CMAC并行的机器人力/位置控制

为提高机器人系统对机器人末端操纵器与外界工作环境接触时，其接触刚度不确定性的自适应能力，在机器人力／位置混合控制的基础上，设计出了一种基于自适应模糊与CMAC并行控制的机器人力控制器，采用小脑模型神经控制器实现前馈控制，实现被控对象的逆动态模型，自适应模糊控制器实现反馈控制，保证系统的稳定性，且抑制扰动。以平面两关节机器人进行仿真，仿真结果表明，系统的自适应能力和力跟踪能力有显著的提高，机械手在其末端操纵器与刚性变化范围较大的外界工作环境接触时，具有较强的适应能力，较好地完成了机器人的力／位置控制。     

Multiple self-organizing maps for a visuo-motor system that uses multiple cameras with different fields of view

This article proposes multiple self-organizing maps (SOMs) for control of a visuo-motor system that consists of a redundant manipulator and multiple cameras in an unstructured environment. The maps control the manipulator so that it reaches its end-effector at targets given in the camera images. The maps also make the manipulator take obstacle-free poses. Multiple cameras are introduced to avoid occlusions, and multiple SOMs are introduced to deal with multiple camera images. Some simulation results are shown.     

Stable camera position control of unmanned aerial vehicle with three‐degree‐of‐freedom manipulator for visual test of bridge inspection

This paper describes a camera position control with aerial manipulator for visual test of bridge inspection. Our developed unmanned aerial vehicle (UAV) has three‐degree‐of‐freedom (3‐DoF) manipulator on its top to execute visual or hammering test of the inspection. This paper focuses on the visual test. A camera was implemented at the end of the manipulator to acquire images of the narrow space of the bridge such as bearings, which the conventional UAV without the camera‐attached manipulators at its top cannot achieve the fine visual test. For the visual test, it is desirable that the camera is above the body with enough distance between the camera and the body. As obvious, the camera position in the inertial coordinate system is effected by the movement of the body. Therefore we implement the camera position control compensating the body movement into the UAV. As a result of an experiment, it is assessed that the proposed control reduces the position error of the camera comparing the one of the body. The mean position error of the camera is 0.039 m that is 51.4% of the one of the body. Our world‐first study enables to acquire the image of the bearing of the bridge by a camera mounted at the end effector of aerial manipulator fixed on UAV.     

Incremental visual servo control of robotic manipulator for autonomous capture of non-cooperative target

This paper develops a new autonomous incremental visual servo control law for the robotic manipulator to capture a non-cooperative target, where the control input is the incremental joint angle to avoid the multiple solutions in the existing inverse kinematics. The position and motion of the non-cooperative target are estimated by an eye-to-hand vision system in real time by integrated photogrammetry and extended Kalman filter. The estimated position and motion of the target are fed into the newly developed position-based visual servo control law to drive the manipulator incrementally towards the dynamically predicted interception point between trajectories of the end effector and the target. To validate the proposed approach, a hardware-in-the-loop simulation has been conducted where the position and motion of the target is estimated by a real eye-to-hand camera and fed into the simulation of the robotic manipulator. The simulation results show the proposed incremental visual servo control law is stable and able to avoid the multiple solutions in the total inverse kinematics.     

Virtual manipulator-based binocular stereo vision positioning system and errors modelling

There is a bottleneck of mobile robots positioning technologies for uncertain goals in complex field environment. Owing to the disturbance of the environment, the objects are hard to be located precisely by robot manipulator. Aiming at the positioning problem, binocular stereo vision system and positioning principle of the picking manipulator in virtual environment (VE) were proposed and expatiated upon; in addition, the manipulator positioning model was built in VE, and the manipulator positioning simulation system was developed by Microsoft Visual C++ 6.0; and the binocular stereo vision system platform with a three-coordinate guideway positioning was constructed for test; what’s more the error sources of vision positioning system was analyzed, and the camera system error was established; the mathematical model of experimental error and the camera calibration matching error were also found; with the developed robot manipulator positioning simulation software and vision system hardware, an experimental platform of positioning system was constructed, and using the platform, the stereo vision data was mapped to the manipulator and was guiding the accurate positioning in VE. Finally, experiment of positioning error compensation was carried out. Results of simulation in VE and the experiment showed that the vision positioning method was feasible for positioning in the field environment; it can be applied to control robot operation and to correct the positioning errors in real-time, especially to the long-range precision modelling and error compensation of robots.     

Visibility Enhancement using Autonomous Multicamera Controls with Situational Role Assignment for Teleoperated Work Machines

The aim of this study is to provide a machine operator with enhanced visibility and more adaptive visual information suited to the work situation, particularly advanced unmanned construction. Toward that end, we propose a method for autonomously controlling multiple environmental cameras. Situations in which the yaw, pitch, and zoom of cameras should be controlled are analyzed. Additionally, we define imaging objects, including the machine, manipulators, and end points; and imaging modes, including tracking, zoom, posture, and trajectory modes. To control each camera simply and effectively, four practical camera roles with different combinations of the imaging objects and modes were defined: overview machine, enlarge end point, posture‐manipulator, and trajectory‐manipulator. A real‐time role assignment system is described for assigning the four camera roles to four out of six cameras suitable for the work situation (e.g., reaching, grasping, transport, and releasing) on the basis of the assignment‐priority rules. To test this system, debris‐removal tasks were performed in a virtual reality simulation to compare performance among fixed camera, manual control camera, and autonomous control camera systems. The results showed that the autonomous system was the best of the three at decreasing the number of grasping misses and erroneous contacts and simultaneously increasing the subjective usability and time efficiency.     

利用平面单应分解实现服务机器人视觉伺服

智能空间中家庭服务机器人所需完成的主要任务是协助人完成物品的搜寻、定位与传递。而视觉伺服则是完成上述任务的有效手段。搭建了由移动机器人、机械臂、摄像头组成的家庭服务机器人视觉伺服系统,建立了此系统的运动学模型并对安装在机械臂末端执行器上的视觉系统进行了内外参数标定,通过分解世界平面的单应来获取目标物品的位姿参数,利用所获取的位姿参数设计了基于位置的视觉伺服控制律。实验结果表明,使用平面单应分解方法来设计控制律可简单有效地完成家庭物品的视觉伺服任务。     

基于P89C668单片机的航空数码相机控制系统

以 P89C668 单片机为核心,介绍了一种自主开发的航空数码相机的控制系统,合理利用单片机的固有资源,相互配合完成了相机镜头控制:光圈控制,快门控制;数据异步通讯:开关命令的采集和拍摄状态信息的回传;PC 方式对 CCD 驱动单元配置等多项功能,并编写了相应的控制软件.控制系统模块设计清晰,工作稳定可靠,成功的以单片微型计算机实现了航空相机多项控制功能的要求,为系统功能的进一步开发提供了充足的硬件资源和软件平台,是一个实用的航空数码相机控制系统.     

A human–robot interface using particle filter,Kalman filter,and over-damping method

This paper presents a novel human–manipulator interface which copies the hand motion to control a manipulator. In the proposed interface, an inertial measurement unit is used to measure the orientation of the human hand, and a 3D camera is employed to locate the human hand using the Camshift algorithm. Although the position and the orientation of the human can be obtained from two sensors, the measurement errors increase over time due to the noise of the devices and the tracking errors. Therefore, particle filter and Kalman filter are used to estimate the position and the orientation of the human hand. Due to the limitations of the perceptive and the motor, human operator cannot accomplish the high-precision manipulation without any assistance. An over-damping method is employed to assist the operator to improve the accuracy and reliability in determining the postures of the manipulator. The human–manipulator interface system was experimentally tested in a lab environment, and the results indicate that such an interface can successfully control a robot manipulator even when the operator is not an expert.     

An adaptive observer for a spacecraft–manipulator system using a camera mounted on its spacecraft

This paper deals with a motion control system for a space robot with a manipulator. Many motion controllers require the positions of the robot body and the manipulator hand with respect to an inertial coordinate system. In order to measure them, a visual sensor using a camera is frequently used. However, there are two difficulties in measuring them by means of a camera. The first one is that a camera is mounted on the robot body, and hence it is difficult to directly measure the position of the robot body by means of it. The second one is that the sampling period of a vision system with a general-purpose camera is much longer than that of a general servo system. In this paper, we develop an adaptive state observer that overcomes the two difficulties. In order to investigate its performance, we design a motion control system that is constructed by combining the observer with a PD control input, and then conduct numerical simulations for the control system. Simulation results demonstrate the effectiveness of the proposed observer.     

基于幂次趋近率的机械手滑模控制系统

为实现对机械手的快速高精度跟踪,采用滑模变结构控制算法对机械手进行控制。针对机械手在趋近滑模面的过程中所存在的抖震问题,在基于模糊补偿的鲁棒自适应控制的基础上,设计了一种基于趋近率的自适应模糊滑模机械手控制系统,使得系统能更快的趋近滑模面,削弱系统抖震现象。基于Matlab/Simulink仿真平台上搭建了机械手控制系统,仿真结果表明,加入趋近率能加快系统趋近滑模面,提高了系统的稳定性和跟踪性能。