Using PCA in time-of-flight vectors for reflector recognition and 3-D localization

This paper presents a reflector recognition and localization technique in three-dimensional (3-D) environments, using only times-of-flight (TOFs) data obtained from ultrasonic transducers. The recognition and localization technique is based on the principal component analysis applied to the TOF vectors originating from a sensor that contains two emitting transducers and several receivers. The two emitters simultaneously transmit two coded pulses that are detected later on and discriminated by the receivers, after being reflected in the environment. The proposed technique allows for the possibility of not only recognizing the reflectors, but also estimating approximately its localization referred to the sensor. This technique has been tested with three types of reflectors in 3-D environments: planes, edges, and corners. The achieved results are very satisfactory for reflectors located in the range 50-350 cm.     

移动机器人的一种室内自然路标定位法

实时定位是移动机器人导航的一个基本前提。该文提出了一种利用墙棱边及墙平面(EdgeandPlane,EP)路标或者广义EP路标进行定位的方法,使用了异步数据融合的方法对移动机器人进行了定位。仅利用传感器对墙平面的距离数据进行测量就实现了机器人的定位。仿真显示这些方法能减少机器人的定位时间,提高对传感器测量数据的利用效率。     

一种用于拱泥机器人位姿检测的倾角传感器

基于霍尔效应的原理 ,为节杆式拱泥机器人研制了一种新型倾角传感器 ,详细介绍了原理结构 ,设计了信号处理和采集电路 ,并对传感器进行了初步测试。     

Sensor Selection by GMB-REM in Real Robot Position Estimation

Modelling and reducing uncertainty are two essential problems with mobile robot localisation. Previously we developed a robot localisation system, namely, the Gaussian Mixture of Bayes with Regularised Expectation Maximisation (GMB-REM), using a single sensor. GMB-REM allows a robot"s position to be modelled as a probability distribution, and uses Bayes" theorem to reduce the uncertainty of its location. In this paper, a new system for performing sensor selection is introduced, namely an enhanced form of GMB-REM. Empirical results show the new system outperforms GMB-REM using sonar alone. More specifically, it is able to select between multiple sensors at each robot"s position, and further minimises the average robot localisation error.     

Three-dimensional tracking using qualitative bionic sonar

A sonar-driven robot, ROBAT^3D, has been implemented to track an object moving in three dimensions using qualitative interpretation of the sonar signals. ROBAT^3D is equipped with a sonar system consisting of five identical transducers configured in the form of a cross. The center transducer emits an acoustic pulse and the echoes are detected by pairs of receivers that flank the transmitter horizontally and vertically. The vertically-oriented receivers are used to control the pitch while those oriented horizontally control the yaw. ROBAT^3D is driven by four air jets that provide lateral forces that direct the heading toward the object. Two bits of information are extracted from each emission, one for pitch correction and the other for yaw correction. The correction is determined by which sensor in a pair first detects the echo. That sensor actuates an air valve supplying the contralateral jet to correct the heading. The range to the object can be determined from the echo time-of-flight. This simple nonlinear analog control system is very fast and can track an object that has an angular velocity upto π /2 rad /s. A trade-off exists between the size of a limit cycle oscillation and the bandwith of the system, determined by the thrust of the jets and the delay in the sonar sensing.     

机器人压力传感器设计及其信息处理

针对传统压力传感器存在的种种不足,探讨了一种基于聚合体薄膜力敏电阻材料的机器人压力传感器的工作机理和研发技术;主要研究了该传感器的压电转换电路、信息采集模块与传输电路的硬件设计和基于小波变换的传感器信号的数字化滤波方法;研制了压力传感器的原理样机,并进行了性能测试实验,实验结果表明,所设计的机器人压力传感器的分辨率可达0.5%,响应时间为6ms,且具有线性关系好、抗干扰能力强的特点。     

A three-dimensional measurement system for robot applications

This paper presents a 3D noncontacting sensor system designed to measure the position and orientation of a robot end effector. This measurement system includes two parts: a tridimensional object including four spheres placed along the axes of a tetrahedron and a set of three orthogonally pointed cameras. The purpose is to design a measurement system characterized by easy relationships in order to satisfy real-time constraints. The system has been used in two experiments: first, to calibrate a parallel robot and validate the geometrical control performance, then as an exteroceptive sensor in an assembly task. The system computes position and orientation of the tetrahedron in 100 ms time. The position and orientation accuracy are, respectively, 0.6 mm and 0.2 deg in a workspace, being a cube with 0.3 m sides.     

一种低功耗程控滤波器的设计

针对目前移动机器人同时定位与地图创建(SLAM)研究中多采用激光雷达或超声环作为测距传感器导致系统复杂、成本高的问题,提出了一种利用舵机带动单超声传感器扫描的低成本设计方案。在高斯超声模型基础上,利用贝叶斯公式对栅格地图进行概率更新,并结合Sobel边缘检测算法提取特征点,实现了由不确定的移动机器人坐标系向固定的以环境特征点为原点的全局环境坐标系的转换及全局定位,为在相同环境下通过重复实验进行多地图融合研究奠定了基础。该低成本移动机器人设计的有效性通过实验得以验证。     

一种高实时性滑觉传感器滑动程度判别模式

光电滑觉传感器是利用光电效应原理,将机械的滑动通过光信号转换为电信号加以检测。光电滑觉传感器的实时性与传感器对滑动程度的判别模式直接相关。通过分析典型的滑动信号,对比传统的滑动程度判别模式,提出了一种新的高实时性滑动程度判别模式,即根据滑动信号单个波形和时间轴包围面积,与滑动信号最大值和波形所占时间乘积的比值大小来判断滑动程度。经试验验证:当上述比值小于25%时,被抓物体与机械手间没有相对滑动。     

An Active System for Three-Dimensional Localization of Mobile Robots

This paper presents an active system, which is composed of a laser range finder and four artificial reflectors, for the three-dimensional (3D) localization of a mobile robot. In this system, it will be proved that the position and the orientation of a mobile robot in a 3D space with respect to a reference frame can be determined provided that the four artificial reflectors are not installed in the same plane. Since the artificial reflectors cannot be treated as points in practice, the proposed localization procedure will be formulated as a nonlinear programming problem to account for actual sizes of the artificial reflectors. To show the validity and feasibility of the proposed method, a series of experiments will be given for illustration.     

Guide robot intelligent navigation in urban environments

This paper presents an intelligent robotic system to guide visually impaired people in urban environments. The robot is equipped with two laser range finders, global positioning system (GPS), camera, and compass sensors. All the sensors data are processed by a single laptop computer. We have implemented different navigation algorithms enabling the robot to move autonomously in different urban environments. In pedestrian walkways, we utilize the distance to the edge (left, right, or both) to determine the robot steering command. In difference from pedestrian walkways, in open squares where there is no edge information, artificial neural networks map the GPS and compass sensor data to robot steering command guiding the visually impaired to the goal location. The neural controller is designed such as to be employed even in environments different from those in which they have been evolved. Another important advantage is that a single neural network controls the robot to reach multiple goal locations inside the open square. The proposed algorithms are verified experimentally in a navigation task inside the University of Toyama Campus, where the robot moves from the initial to goal location.     

机器人力控制算法试验平台的设计与实现

本文针对机器人力控制算法试验平台搭建中力传感器通讯模块的软件设计与实现做了详细研究。该试验平台采用CAN2.0A协议,并利用该协议实现了力传感器与机器人控制器之间的通讯。从控制算法试验的效果来看,该平台达到了力控制试验的要求,具有良好的应用价值。     

基于超声测距的工业机器人避障控制系统设计

工业机器人对于自身与障碍物之间的距离测量不准确,无法根据二者距离判断行驶路径,导致避障效果较差。为此基于超声测距技术设计了一种新的工业机器人避障控制系统,从硬件和软件两方面对避障效果进行优化设计。将具有脉冲信号的超声换能器安装在单片机的操作模块中,增加MOS功率器件作为超声换能器的驱动元件,应用EA1、EA2和EA3三种型号的误差放大器,将回波信号稳定放大到电路中,利用运算放大器和RC网络电路实现滤波放大,利用信号检测电路实现检测。利用超声波传感器精准测量出自己与障碍物之间的距离,通过建立模糊数据库、定位漫反射信息、提取不同方向的测距信息实现工业机器人避障控制。实验结果表明,设计的基于超声测距的工业机器人避障控制系统能够准确测量出与障碍物之间的距离,避障控制准确率平均值达97.4%,能够实现工业机器人避障防碰撞操作。     

3-D imaging systems and high-speed processing for robot control

Bin picking by a robot in real time requires the performance of a series of tasks that are beyond the capabilities of commercially available state-of-the-art robotic systems. In this paper, a laser-ranging sensor for real-time robot control is described. This sensor is incorporated into a robot system that has been applied to the bin-picking or random-parts problem. This system contains new technological components that have been developed recently at the Environmental Research Institute of Michigan (ERIM). These components (the 3-D imaging scanner and a recirculating cellular-array pipeline processor) make generalized real-time robot vision a practical and viable technology. This paper describes these components and their implementation in a typical real-time robot vision system application.     

机器人超声接近觉传感器的研究

根据机器人超声接近觉的实际要求选择了超声探头,研制了相应的模拟控制电路和数字控制电路,并根据机器人控制系统结构的需要设计了相应的信号采集电路部分,对机器人超声接近觉传感器进行了某些研究.进行的校准后所作的性能测试已经表明,该接近觉传感器可以满足机械手控制的实际需要。     

移动机器人的多传感器测距系统设计

在移动机器人的路径规划过程中,必须掌握障碍物的距离信息.基于超声波和红外传感器的测距原理,设计了一种移动机器人多传感器测距系统,可测量0～200 cm距离内存在的障碍物,测量误差小于1 %.采用超声波和红外2种传感器组成3组测距采集系统,采集机器人3个不同方位的障碍物信息,解决了单一传感器测距盲区的问题,并详细介绍了该系统的软件和硬件设计.     

Fiber laser-based temperature sensor systems using uniform wavelength-matched Bragg grating reflectors

A detailed investigation has been carried out into the output characteristics of a fiber laser forming, as it does the basis of an optical sensor system, in terms of its wavelength, signal intensity and linewidth, and the output spectrum when each individual fiber Bragg grating, acting as the reflectors of the laser system, has been allowed to respond to temperature in a wavelength-matched normal Bragg grating-based laser configuration. An analytical model has been created reflecting the relationship between the grating bandwidth and the temperature under each operational condition and the results obtained have significant implication for the optimum design of this type of fiber laser-based sensors. Additionally, experiments were performed to investigate the output characteristics of a fiber laser-based sensor when used for temperature measurement.     

Reduction of blind zone in ultrasonic transmitter/receiver transducers

Most ultrasonic sensorial systems are based on transducers that work as emitters and receivers in the same scanning process. This fact implies that, during the emission process, the reception stage stays disabled, in order to avoid the emission coupled. This disabling interval provides that the nearest area to the transducers, the blind zone, cannot be scanned, since echoes coming from reflectors placed inside it are overlapped with the coupled emission. On the other hand, the encoding of the ultrasonic emission by binary sequences allows the process gain to be increased, so better precision is achieved and higher levels of noise are supported by the system. The length of the used binary sequence determines not only the process gain, but also the duration of the emission interval. The usage of long sequences to improve the performance also implies the existence of a larger blind zone, where reflectors are not detected. This work presents a novel encoding technique, based on Golay complementary pairs, where the dimension of the blind zone is reduced to negligible distances thanks to some features from the binary sequences.     

A sensor for dynamic tactile information with applications in human–robot interaction and object exploration

We present a novel tactile sensor, which is applied for dextrous grasping with a simple robot gripper. The hardware novelty consists of an array of capacitive sensors, which couple to the object by means of little brushes of fibers. These sensor elements are very sensitive (with a threshold of about 5 mN) but robust enough not to be damaged during grasping. They yield two types of dynamical tactile information corresponding roughly to two types of tactile sensor in the human skin. The complete sensor consists of a foil-based static force sensor, which yields the total force and the center of the two-dimensional force distribution and is surrounded by an array of the dynamical sensor elements. One such sensor has been mounted on each of the two gripper jaws of our humanoid robot and equipped with the necessary read-out electronics and a CAN bus interface. We describe applications to guiding a robot arm on a desired trajectory with negligible force, reflective grip improvement, and tactile exploration of objects to create a shape representation and find stable grips, which are applied autonomously on the basis of visual recognition.