基于视觉信息的移动机器人控制系统设计

机器人的视觉相当于机器人的眼睛,机器人视觉系统是当下研究热点。本文主要研究基于视觉信息的机器人系统,通过对获得的图像信息的处理来实现对机器人的控制。详细讨论了摄像机标定、图像处理等方面的设计,实现了对机器人控制系统的设计。     

基于高维状态空间的移动机器人定位

位置跟踪是移动机器人自主导航中的一个主要任务.扩展的卡尔曼滤波定位方法是一个常用的位置跟踪方法,但是在对非线性系统方程进行线性化近似过程中引入了线性化误差.文中给出了一个基于线性系统模型的位置估计方法.用一个高维的状态向量表示机器人的位置空间,并选用环境路标的全局信息作为观测向量,此时系统动态模型和系统观测模型都是线性的,从而直接运用最优的线性卡尔曼滤波技术进行移动机器人位置估计.这种方法免除了非线性方程的线性近似过程,避免了线性化误差.实验表明,位置估计过程是收敛的、一致的.     

基于天花板的移动机器人视觉定位方法的研究

为了实现室内移动机器人的自定位,考虑到室内的复杂程度和环境特色,设计一种基于单目视觉的移动机器人定位系统。机器人在室内带有天花板路标信息的环境下,以颜色和形状结合的路标作为特征,通过机器人头顶与天花板垂直的摄像机,运用彩色图像分割轮廓矩匹配的方法识别路标,解析路标携带的世界坐标信息,从而计算出机器人的全局位置和航向角。该方法大大提高了图像处理和特征提取的速度,通过实验验证,其满足定位系统的实时性和鲁棒性要求。     

Design and evaluation of a micro-fuel-cell-based power system for a mobile robot

A mobile robot being used for an undergraduate course in mechatronics engineering was converted from a conventional lead acid battery to a hydrogen fuelled polymer electrolyte membrane (PEM) micro fuel cell as the power source. The application of the robot is first outlined. Next, the design of the fuel-cell-based power supply system as assembled from the commercial components is described. Finally, the performance of the fuel cell is documented. The performance was found to match that of the conventional battery. An operational problem associated with the purging of water had to be solved. Although the cost of the fuel cell was 50 times that of the battery, the exercise did serve to demonstrate the potential of the technology.     

基于视觉感知的巡线机器人系统

本文设计制作了一套巡线机器人系统,实现了图像的采集处理及飞行姿态的控制。该系统利用飞控结合串级双闭环PID对无人机进行姿态稳定控制,通过对摄像头采集到的图像进行处理,融合飞控模块的姿态数据,完成悬停、巡线等功能。该系统具有结构简单,控制精度高,抗干扰能力强等特点。     

一种基于DSP的移动机器人运动控制器设计

分析了运动控制器对机器人的重要性;提出了一种高性能的基于DSP芯片的运动控制器的整体设计方案,该控制器集控制电路、数据采集模块和驱动电路于一体,能够很好的完成机器人运动轨迹和位置的控制。设计了控制器的硬件电路,重点介绍了驱动电路和电源电路的设计过程。最后,为了实现控制要求,对软件进行了相应的设计。     

移动机器人平衡控制系统研究与设计

控制系统以AT89S52单片机为核心,由直流减速电机驱动电路、引导线检测电路、倾角检测电路、路程检测电路、键盘显示电路、电源电路等组成,可以实现移动机器人自动寻迹、确定平衡点,同时具有操作时间显示、路程累计等功能.利用PWM技术对直流减速电机进行调速,采用红外传感器来寻线和检测机器人运动方向,倾角传感器来检测平衡板的角度,并对传感器输出的电压信号进行了滤波处理.     

移动机器人超声波测距避障系统设计

测距避障是移动机器人适应未知复杂环境的能力之一,准确测出移动机器人和障碍物之间的距离是关键。以dsPIC33FJ256MC710单片机为核心研究设计了一种移动机器人超声波测距避障系统。该系统利用脉冲回波法测距,针对超声波在空气中的传播速度受环境温度的影响,设计了超声波速度温度补偿电路。实验结果表明该超声波测距避障系统测量数据准确,能够满足移动机器人在复杂环境中避障的需求。     

智能轮式移动机器人嵌入式控制系统设计

为了优化智能轮式移动机器人的控制系统,提出了一种基于ARM微处理器和复杂可编程逻辑器件(CPLD)的嵌入式控制系统.硬件部分采用以ARM和CPLD为核心的模块化设计,软件部分采用实时操作系统μC/OS-Ⅱ,并设计了电机速度调节的控制算法.实现了对机器人驱动电机、超声传感等任务模块的系统控制.仿真和运行实验结果表明,系统运行稳定,控制灵活,达到预期的设计目标.     

A tele-operated mobile ultrasound scanner using a light-weight robot.

This paper presents a new tele-operated robotic chain for real-time ultrasound image acquisition and medical diagnosis. This system has been developed in the frame of the Mobile Tele-Echography Using an Ultralight Robot European Project. A light-weight six degrees-of-freedom serial robot, with a remote center of motion, has been specially designed for this application. It holds and moves a real probe on a distant patient according to the expert gesture and permits an image acquisition using a standard ultrasound device. The combination of mechanical structure choice for the robot and dedicated control law, particularly nearby the singular configuration allows a good path following and a robotized gesture accuracy. The choice of compression techniques for image transmission enables a compromise between flow and quality. These combined approaches, for robotics and image processing, enable the medical specialist to better control the remote ultrasound probe holder system and to receive stable and good quality ultrasound images to make a diagnosis via any type of communication link from terrestrial to satellite. Clinical tests have been performed since April 2003. They used both satellite or Integrated Services Digital Network lines with a theoretical bandwidth of 384 Kb/s. They showed the tele-echography system helped to identify 66% of lesions and 83% of symptomatic pathologies.     

模块化机器人移动定位系统的应用和研究

移动定位是机器人执行任务的基础,没有精确的定位系统,移动机器人无法完成所要求的工作。基于Arduino模块设计实现了一个简单的机器人移动定位系统,系统以Arduino模块作为移动机器人的控制核心。简单介绍了移动定位理论,着重阐述定位系统的软硬件设计。系统采用Zig Bee无线传感网络定位方法,利用Zig Bee大范围定位无误差特性,使移动机器人快速准确定位,基于Zig Bee无线传感网络定位范围较小、精确度低的缺陷,对测距定位算法进行了一定的改进。最后经试验验证,所设计的移动定位系统定位误差较小,满足实际需求。     

Client-server-based mobile robot control

A control architecture for an autonomous mobile robot usually consists of two components: (1) intelligent control software and (2) an operating system for resource access. From the point of view of a computer scientist, it is desirable to achieve a certain level abstraction from the resource (be it sensor or effector). Here, this is achieved by introducing a client-server framework for realizing abstract resource access and intelligent control. Hardware details are hidden in a middleware layer, which is inserted in between operating system and applications. In this paper, we present the most important features of our client-server approach. The servers decouple hardware and software dependencies. Communication is realized through the use of classes, offering a wide variety of client-server interaction. Event-driven servers and clients lead to quick responses in dynamic environments. Our approach gives reusability, portability, testability, and maintainability through data abstraction. It was successfully applied in our experimental platform ARS     

A position control differential drive wheeled mobile robot

For more accurate path tracking of a four-wheeled two-degrees-of-freedom mobile robot (WMR), a position control algorithm is proposed with two separated feedback loops, a velocity feedback loop and a position feedback loop. In the most conventional position control system of a WMR, internal error is mainly considered, while external error has, as yet, hardly been treated, although it plays an important role in accurate position control. This external error is caused by unexpected environmental situations. The proposed control algorithm is designed to compensate for both internal error and external error. This algorithm makes it possible to accurately follow the designed trajectory     

Stochastic event capturing with a single mobile robot in rectangular perimeters

In this paper, we are interested in a single robot detecting intrusions across a rectangular perimeter. We build a stochastic model to analyze the detection quality achieved by a single robot moving along the rectangular perimeter, based on the velocity and the mobility pattern. We define the following intrusion event mode: intrusions occur at a random point along the rectangular perimeter, and stay at that point for a random length of time. In our model, a robot is set to periodically move along a certain route at a variable speed. We derive the general expression for intrusion loss probability. Under the reasonable assumption that, once an intrusion takes place at a random point in the rectangular perimeter, it stays there for a random length of time, which follows an exponential distribution, we then derive the solution to the above problem.     

Autonomous and teleoperation control of a mobile robot

The present work proposes an autonomous tracking control system and a control structure to combine autonomous and teleoperation commands in a bicycle-type mobile robot. This compounded operation renders great flexibility to the control system of the mobile robot. For autonomous operation, a simple tracking controller that includes compensation of the robot dynamics is developed. This tracking control system is proved to be stable in the sense that it asymptotically reaches the tracking objective. Teleoperation with visual access to the robot’s workspace is integrated via a joystick with the autonomous operation of the robot. Simulations and experimental results on a prototype robot show the feasibility and performance of the proposed control system.     

RFID-based mobile robot guidance to a stationary target

Retrieving accurate location information about an object in real-time, as well as any general information pertinent to the object, is a key to enabling a robot to perform a task in cluttered, dynamically changing environment. In this paper, we address a novel technique for the guidance of mobile robots to help them identify, locate, and approach a target in our daily environments. To this end, we propose a standard for the use of radio-frequency identification (RFID) systems and develop a prototype that can be easily installed in the existing mobile robots.Specifically, when an RF signal is transmitted from an RF transponder, the proposed RFID system reads the transponder-encoded data and simultaneously picks up the direction of the transponder using the received signal strength pattern. Based on the angle of signal arrival, we develop the guidance strategies that enable a robot to find its way to the transponder position. Moreover, to cope with multi-path reflection and unexpected distortions of the signals that resulted from environmental effects, we present several algorithms for reconstructing the signals. We demonstrate that an off-the-self mobile robot equipped with the proposed system locates and approaches a stationary target object. Experimental results show that the accuracy of the proposed system operating at a frequency of 315 MHz falls within a reasonable range in our normal office environment.     

A kinematic-dual snake robot: Undulatory mobile robot driven by controllable side-thrust links

This paper introduces the notion of a kinematic-dual snake robot, as contrasted with a conventional wheeled snake robot. The well-known original snake robot consists of active joints, passive wheels, and corresponding side-slip constraints. The purpose of this study is to present a string-like mobile mechanism as a solution to the difficulty of manipulating the original snake. The key idea in devising the proposed snake is to reverse the mechanical elements of the original snake and then refine the reversed mechanism by the kinematics so that it is a dual system of the original snake. Thus, the proposed snake consists of passive joints and active omnidirectional wheels plus two ordinary wheels at the ends, associated with side-slip constraints. Here, we introduce the concept of the kinematic-dual snake and explain in what sense it is kinematic-dual. Then, through controllability analysis, motion planning, and experiments, we prove that the concept of the kinematic-dual snake is reliable as a mobile mechanism. The proposed robot can improve its manipulability while maintaining the advantages of the string-like body. The authors expect this idea would contribute to tasks that require both joint angle manipulation and traveling, such as transportation with wrapping around an object.     

无线移动机器人及运动监测系统的设计

介绍了一种无线两轮驱动机器人小车和软硬件实现方法,计算机通过串口无线控制机器人小车和接收机器小车反馈回来的运动状态信息。在对几种近距无线通信协议进行分析和比较的基础上,选用Zigbee协议栈技术作为基本的通信协议,并基于该协议实现遥控机器人小车和监测小车的运动状态,通过监测机器人的运动状态来提高控制的准确度。CC2430无线单片机负责无线通信和组网,MSP430单片机作为主控制芯片,MSP430通过产生两路PWM波来控制两路直流电机,实现机器人根据计算机发出的各种命令执行不同的动作。该机器人已用于危险环境监测研究当中。     

轮式移动机器人运动控制系统研究与设计

基于差速转向原理,设计了一套轮式移动机器人的运动控制系统。首先选择小车的模型(运动模型),进行运动学和力学分析,得出左右两侧车轮的速度约束,然后设计机器人的运动控制模块和无线遥控模块。运动控制模块可分为控制电路和驱动电路两大模块,控制电路以DSP作为核心控制部件,捕获编码器的信息并产生PWM信号;驱动电路以直流电机H桥集成芯片为驱动部件,接收来自DSP的控制信号。无线遥控模块选用AVR单片机作为控制核心,实现A/D转换和指令发送等功能。实验证明,该系统不仅能实现较长距离的无线控制,传输可靠,而且速度控制准确,车体运动灵活。