Biologically Inspired Visual Motion Detection in VLSI

Visual motion detection is a fundament component of vision, and plays a vital role in scene analysis and understanding for behaving organisms. In computer vision, motion detection requires considerable resources to obtain real-time results. Very Large Scale Integration (VLSI) technology offers a convenient substrate upon which both photosensitive elements and motion extracting circuits can be implemented, thus allowing real-time motion detection. This paper presents two approaches for implementing real-time visual motion detection in VLSI. The two approaches mimic the two primary methods found in biological organisms. Insect motion detection employs local correlation and is implemented very close to the photoreceptors. In contrast, primate motion detection is performed in cortex, using spatiotemporally oriented neural filters. The analysis, construction and results of the hardware models of insect and primate visual motion detection are presented.     

仿生六足机器人图像采集卡USB驱动技术研究

针对仿生六足机器人作业任务的具体情况,设计了一款具有USB接口的图像采集卡;该采集卡采用FPGA/CPLD进行图像采集和控制,通过USB接口完成图像数据的传输,具有体积小、速度快、功耗低和实时性好等特点;由于该采集卡是仿生六足机器人视觉子系统的重要组成部分,在视觉子系统中应与其他器件进行合理挂接,因而必须妥善解决USB驱动问题;通过研究和探索,编写了USB设备驱动程序,并使用2个URB来轮流读取,提高了接收效率;调试编译的结果表明该USB设备驱动程序具有良好的实时性和可移植性,有效提高了仿生六足机器人视觉子系统的工作效率。     

Biologically inspired decision-making in the robot platform MAMoRo

An important step in coming near to building machines with artificial intelligence is by studying and understanding how the human brain works, then applying this knowledge to build machines that “think” using the same concept. MAMoRo (modular autonomous mobile robot) is a general-purpose robot platform targeted at teaching and research in the academia. It consists of three modules: power and motion module, control module, and intelligence module. The decision unit of MAMoRo is distributed into two modules: the control module, which is equipped with a low-cost microcontroller, and handles low-level hardware functions, and the intelligence module, which is equipped with a field-programmable gate array (FPGA) and handles high-level functions. This model of distribution was inspired by the anatomy of the human brain and brings with it many advantages. To prove the concept, MAMoRo was tested with a practical application. This work was presented in part at the First European Workshop on Artificial Life and Robotics, Vienna, Austria, July 12–13, 2007     

多移动机器人编队的行为选择控制系统

针对多机器人在编队行进过程中的行为选择问题进行了分析,提出一种实现多移动机器人编队的行为选择机制。通过计算机仿真和实验研究,结果表明该控制策略能很好的实现多机器人快速编队,并在编队过程中实现运动状态的平滑变化,提高了整个系统性能。     

基于遥操作和局部自主的移动机器人越障

根据任务需要,研制了具有翻倒恢复功能的关节履带式移动机器人;构建了基于网络通信的遥操作系统,通过人机交互界面完成终端对移动机器人的遥控操作,鉴于履带式移动机器人开环控制的不足,提出遥操作和局部自主控制的翻倒恢复控制方法;实验表明,提出的方法在移动机器人实际作业中有效可行。     

Coupled Oscillator Control of Autonomous Mobile Robots

This paper introduces a nonlinear oscillator scheme to control autonomous mobile robots. The method is based on observations of a successful control mechanism used in nature, the Central Pattern Generator. Simulations were used to assess the performance of oscillator controller when used to implement several behaviors in an autonomous robot operating in a closed arena. A sequence of basic behaviors (random wandering, obstacle avoidance and light following) was coordinated in the robot to produce the higher behavior of foraging for light. The controller is explored in simulations and tests on physical robots. It is shown that the oscillator—based controller outperforms a reactive controller in the tasks of exploring an arena with irregular walls and in searching for light.     

改进的生物激励神经网络的机器人路径规划

介绍了基于生物激励神经网络的移动机器人路径规划。机器人的路径生成过程是由神经网络组成动态变化的神经元活性值状态路线图实现的。通过神经元活性值的传播,机器人被吸引到目标点,而同时障碍物使自己处在活性值最低点,起到推开机器人避碰的目的。仿真研究表明该方法生成的由起始点到目标点的路径是连续的、平滑的、避障的,不会陷入U形障碍物,与障碍物形状和所处位置无关,能对快速变化的环境做出迅速反应。但在当前位置邻近位置中具有最大活性值的位置不惟一的情况下,产生路径可能不理想,即到达目标点的避障路径是较长的,而不是最短或者是接近最短的。文中对该不足进行了分析,并提出了改进方法,使生成路径是最短的或是接近最短。对改进方法进行了仿真,实验结果证明该方法是有效的和可行的。     

Planetary Rover Developments Supporting Mars Exploration, Sample Return and Future Human-Robotic Colonization

We overview our recent research on planetary mobility. Products of this effort include the Field Integrated Design & Operations rover (FIDO), Sample Return Rover (SRR), reconfigurable rover units that function as an All Terrain Explorer (ATE), and a multi-Robot Work Crew of closely cooperating rovers (RWC). FIDO rover is an advanced technology prototype; its design and field testing support NASA's development of long range, in situ Mars surface science missions. Complementing this, SRR implements autonomous visual recognition, navigation, rendezvous, and manipulation functions enabling small object pick-up, handling, and precision terminal docking to a Mars ascent vehicle for future Mars Sample Return. ATE implements on-board reconfiguration of rover geometry and control for adaptive response to adverse and changing terrain, e.g., traversal of steep, sandy slopes. RWC implements coordinated control of two rovers under closed loop kinematics and force constraints, e.g., transport of large payloads, as would occur in robotic colonies at future Mars outposts. RWC is based in a new extensible architecture for decentralized control of, and collective state estimation by multiple heterogeneous robotic platforms—CAMPOUT; we overview the key architectural features. We have conducted experiments with all these new rover system concepts over variable natural terrain. For each of the above developments, we summarize our approach, some of our key experimental results to date, and our future directions of planned development.     

Traversability Analysis and Path Planning for a Planetary Rover

A method of analyzing three-dimensional data such as might be produced by stereo vision or a laser range finder in order to plan a path for a vehicle such as a Mars rover is described. In order to produce robust results from data that is sparse and of varying accuracy, the method takes into account the accuracy of each data point, as represented by its covariance matrix. It computes estimates of smoothed and interpolated height, slope, and roughness at equally spaced horizontal intervals, as well as accuracy estimates of these quantities. From this data, a cost function is computed that takes into account both the distance traveled and the probability that each region is traversable. A parallel search algorithm that finds the path of minimum cost also is described. Examples using real data are presented.     

Qualitative Navigation for Autonomous Wheelchair Robots in Indoor Environments

This article describes a novel qualitative navigation method for autonomous wheelchair robots in typical home environments. The method accepts as input a line diagram of the robot environment and converts it into an enhanced grid in which qualitative representations of variations in sensor behavior between adjacent regions in space are stored. An off-line planner uses these representations to store at each grid cell appropriate motion commands that will ideally move the wheelchair in and out of each room in a typical home environment. An online controller accepts as input this enhanced grid along with a starting and goal position for the robot. It then compares the actual behavior of the sensors with the one stored in the grid. The results of this comparison are used to estimate the current position of the robot, to retrieve the planner instructions and to combine these instructrions with appropriate risk avoidance behaviors during navigation. This method has been tested both in simulation and as one of the subsystems on a prototype for an autonomous wheelchair robot. Results from both trials are provided.     

RHex: A Biologically Inspired Hexapod Runner

RHex is an untethered, compliant leg hexapod robot that travels at better than one body length per second over terrain few other robots can negotiate at all. Inspired by biomechanics insights into arthropod locomotion, RHex uses a clock excited alternating tripod gait to walk and run in a highly maneuverable and robust manner. We present empirical data establishing that RHex exhibits a dynamical (bouncing) gait—its mass center moves in a manner well approximated by trajectories from a Spring Loaded Inverted Pendulum (SLIP)—characteristic of a large and diverse group of running animals, when its central clock, body mass, and leg stiffnesses are appropriately tuned. The SLIP template can function as a useful control guide in developing more complex autonomous locomotion behaviors such as registration via visual servoing, local exploration via visual odometry, obstacle avoidance, and, eventually, global mapping and localization.     

Design and Control of Autonomous Underwater Robots: A Survey

During the 1990s, numerous worldwide research and development activities have occurred in underwater robotics, especially in the area of autonomous underwater vehicles (AUVs). As the ocean attracts great attention on environmental issues and resources as well as scientific and military tasks, the need for and use of underwater robotic systems has become more apparent. Great efforts have been made in developing AUVs to overcome challenging scientific and engineering problems caused by the unstructured and hazardous ocean environment. In the 1990s, about 30 new AUVs have been built worldwide. With the development of new materials, advanced computing and sensory technology, as well as theoretical advancements, R&D activities in the AUV community have increased. However, this is just the beginning for more advanced, yet practical and reliable AUVs. This paper surveys some key areas in current state-of-the-art underwater robotic technologies. It is by no means a complete survey but provides key references for future development. The new millennium will bring advancements in technology that will enable the development of more practical, reliable AUVs.     

A Flexible Control Architecture for Mobile Robots: An Application for a Walking Robot

To get the best features of both deliberative and reactive controllers, present mobile robot control architectures are designed to accommodate both types of controller. However, these architectures are still very rigidly structured thus deliberative modules are always assigned to the same role as a high-level planner or sequencer while low-level reactive modules are still the ones directly interacting with the robot environment. Furthermore, within these architectures communication and interface between modules are if not strongly established, they are very complex thus making them unsuitable for simple robotic systems. Our idea in this paper is to present a control architecture that is flexible in the sense that it can easily integrate both reactive and deliberative modules but not necessarily restricting the role of each type of controller. Communication between modules is through simple arbitration schemes while interface is by connecting a common communication line between modules and simple read and/or write access of data objects. On top of these features, the proposed control architecture is scalable and exhibits graceful degradation when some of the modules fail, similar to the present mobile robot architectures. Our idea has enabled our four-legged robot to walk autonomously in a structured uneven terrain.     

Localization of an Autonomous Mobile Robot Based on Ultrasonic Sensory Information

Based on ultrasonic sensory information, an approach is proposed for localization of autonomous mobile robot (AMRs). In the proposed method, it will be proven that the combination of three ultrasonic transmitters and two receivers can determine both the position and the orientation of an AMR with respect to a reference frame uniquely. In this manner, since only ultrasonic sensors are used, the proposed method will be highly cost-effective and easy to implement. To show the validity and feasibility of the proposed method, the hardware configuration and a series of experiments will be given for illustration.     

Distributed Control of Multi-Robot Systems Engaged in Tightly Coupled Tasks

NASA mission concepts for the upcoming decades of this century include exploration of sites such as steep cliff faces on Mars, as well as infrastructure deployment for a sustained robotic/manned presence on planetary and/or the lunar surface. Single robotic platforms, such as the Sojourner rover successfully flown in 1997 and the Mars Exploration Rovers (MER) which landed on Mars in January of 2004, have neither the autonomy, mobility, nor manipulation capabilities for such ambitious undertakings. One possible approach to these future missions is the fielding of cooperative multi-robot systems that have the required onboard control algorithms to more or less autonomously perform tightly coordinated tasks. These control algorithms must operate under the constrained mass, volume, processing, and communication conditions that are present on NASA planetary surface rover systems. In this paper, we describe the design and implementation of distributed control algorithms that build on our earlier development of an enabling architecture called CAMPOUT (Control Architecture for Multi-robot Planetary Outposts). We also report on some ongoing physical experiments in tightly coupled distributed control at the Jet Propulsion Lab in Pasadena, CA where in the first study two rovers acquire and carry an extended payload over uneven, natural terrain, and in the second three rovers form a team for cliff access.     

连续型机器人研究综述

连续型机器人是一种新型的仿生机器人,采用“无脊椎”的柔性结构,不具有任何离散关节和刚性连杆．其弯曲性能优良,对障碍物众多的非结构环境和工作空间狭小的受限工作环境适应能力强,不仅可以像传统机器人那样在其末端安装执行器以实现抓取和夹持等动作,还可以利用其整个机器人本体实现对物体的抓取．本文对连续型机器人的仿生原理与结构特点进行了分析,介绍了连续型机器人的研究现状,并对其潜在应用领域和未来研究工作进行了探讨和展望．     

用Visual C＋＋开发控制仿真系统

本文以移动机器人为控制对象,介绍了如何用Ｖｉｓｕａｌ Ｃ＋＋开发位置ＰＩＤ控制器,主要解决用单文档多窗口来对不同参数进行仿真,以达到多视图的仿真效果,主要内容由移动机器人的数学模型和Ｖｉｓｕａｌ Ｃ＋＋软件开发组成。     

全自主移动机器人分层递阶控制研究

本文提出了一种基于多CPU的分层递阶控制策略,应用于全自主移动机器人的结构化设计。以分层递阶控制为核心思想的自主机器人采用智能级、协调级和执行级级连的结构,其中智能级和协调级配备独立的微处理器。实验表明,所设计的自主机器人系统具备良好的环境感知能力和控制精度,可以通过开放的VC++平台实现对机器人的控制。     

Gait Adaptation in a Quadruped Robot

A newborn foal can learn to walk soon after birth through a process of rapid adaptation acting on its locomotor controller. It is proposed here that this kind of adaptation can be modeled as a distributed system of adaptive modules (AMs) acting on a distributed system of adaptive oscillators called Adaptive Ring Rules (ARRs), augmented with appropriate and simple reflexes. It is shown that such a system can self-program through interaction with the environment. The adaptation emerges spontaneously as several discrete stages: Body twisting, short quick steps, and finally longer, coordinated stepping.This approach is demonstrated on a quadrupedal robot. The result is that the system can learn to walk several minutes after inception.