机器人末端臂轨迹跟踪自适应控制设计

本文提出了新颖的机器人末端臂轨迹跟踪自适应控制方法。该方法与已有的神经网络模型不同之处在于数据首先利用运动学反解求出机器人各关节旋转的角度,然后应用径向基函数自组织进行神经网络学习生成模糊规则,利用监督学习算法(SLA)、最小二乘法(LMS)、反向传播算法(BP)和聚类分析的方法在线优化控制规则以及隶属函数的参数。仿真结果表明,该方法不但规则生成的时间少,有效的防止了规则数爆炸,而且在机器人轨迹跟踪控制的应用中效果好。     

A compliant end-effector coupling for vertical assembly: design and evaluation

Many manipulation tasks require compliance, i.e. the robot's ability to comply with the environment and accomplish force as well as position control. Examples are constrained motion tasks and tasks associated with touch or feel in fine assembly. Few compliance-related tasks have been automated, and usually by active means of active compliance control: the need for passive compliance offered by the manipulator itself has been recognized and has led to the development of compliant end-effectors and/or wrists. In this paper we present a novel passively compliant coupling, the compliant end-effector coupling (CEEC), which aids automated precision assembly. It serves as a mechanical interface between the end of the robot arm and the end-effector. The coupling has 6 degrees of freedom. The design of the coupling is based on a “lock and free” assembly idea. The coupling is locked and behaves like a stiff member during robot motion, and is free (compliant) during constrained motion. It features an air bearing, a variable stiffness air spring and a center-locking mechanism. The end-effector assembly, being centrally unlocked, will float within the designed compliance limits assisted by the air bearing. These frictionless and constraint-free conditions facilitate a fast correction of any initial lateral and angular misalignments. In a peg insertion assembly, such accommodation is possible provided that the tip of the peg is contained within the chamfer of the hole. A variable stiffness air spring was incorporated in the design to allow variable and passive vertical compliance. This vertical compliance allows the accommodation of angular and vertical errors. The center-locking mechanism will return the end-effector assembly to its initial position upon an error correction. In a robot application program, the CEEC can be locked during rapid motion to securely transport a part or be set free during assembly or disassembly processes when the motions are constrained.     

A face robot for autonomous simplified musical notation reading and singing

This research is aimed to devise an anthropomorphic robotic head with a human-like face and a sheet of artificial skin that can read a randomly composed simplified musical notation and sing the corresponding content of the song once. The face robot is composed of an artificial facial skin that can express a number of facial expressions via motions driven by internal servo motors. Two cameras, each of them installed inside each eyeball of the face, provide vision capability for reading simplified musical notations. Computer vision techniques are subsequently used to interpret simplified musical notations and lyrics of their corresponding songs. Voice synthesis techniques are implemented to enable the face robot to sing songs by enunciating synthesized sounds. Mouth patterns of the face robot will be automatically changed to match the emotions corresponding to the lyrics of the songs. The experiments show that the face robot can successfully read and then accurately sing a song which is assigned discriminately.     

基于加速度计和磁强计的随钻姿态测量观测模型

水平定向钻进中钻具姿态的实时测量是实现导向的关键因素。推导了钻具姿态角的测量方法,给出了姿态转换矩阵的解算公式。针对姿态测量的非线性问题和已有算法的不足,建立了姿态测量系统的线性观测方程,该观测方程利用加速度计和磁强计分别测得的地球重力场分量和地磁场分量来构造新的观测向量,并以姿态四元数的误差向量作为观测模型的输入。给出了线性观测模型的求解方法,最小二乘递推法。仿真结果表明:该算法收敛速度快,能够得到钻具准确的姿态信息,即使起始姿态的估计值与真实值之间的偏差很大,该算法仍能很好地收敛到真实值。     

A study of an autonomous mobile robot for a sewer inspection system

This article describes a prototype autonomous mobile robot, KANTARO, designed for inspecting sewer pipes. It is able to move autonomously in 200–300-mm-diameter sewer pipes, to turn smoothly through 90° at a junction, and to go down a 5-cm step. KANTARO carries all the resources required, such as a control unit, a camera, a 2D laser, and an IR sensor. Damage or abnormalities in sewer pipes are detected based on recorded sensory data. KANTARO has demonstrated its effectiveness in inspection and in autonomous navigation in a dry sewer test field at the FAIS–Robotics Development Support Office (FAIS–RDSO). This work was presented in part at the 11th International Symposium on Artificial Life and Robotics, Oita, Japan, January 23–25, 2006     

Truly autonomous robots: hardware design for an energy trophallactic robot

This article describes the mechanical and electrical design of a mobile robot called the CISSbot. CISSbot is abbreviated from our center’s name in Danish: Center for Indlejrede Software Systemer. The robots are designed toward truly autonomous robots in large populations through energy trophallaxes. Unlike present mobile robots, the CISSbots are energetically autonomous robots because they are not able not only to autonomously refuel by picking up batteries at a charging station, but also to share energy by exchanging batteries with other robots. The CISSbots basically consist of their own processing power, sensors, and actuators. However, to achieve the capability of battery exchange, the CISSbots need a special design of battery exchange mechanism. In this paper, we present the realization of the design in both the mechanics and the electronics of the CISSbot. Details of the battery exchange technique and power management are clarified. Finally, the article gives an outline of our future work on the CISSbots.     

Hybrid head mechanism of the groundhog-like mine rescue robot

Since mining accidents severely threaten production safety, robotic assistant systems can play an important role by searching and rescuing survivors in hostile underground environments. Accordingly, this paper focuses on the design, modeling and optimization of a 4UPS+PU spatial hybrid manipulator, which serves as the dexterous head section of a quadrupedal, groundhog-like mine rescue robot. This biologically inspired mechanism has three degrees of freedom (DOF), one translation and two rotations. Additionally, a passive leg is connected to both centers of the base and the moving platform in order to constrain undesirable motion. In order to evaluate the operational capacity, an analysis of the mobility and the inverse kinematics are conducted. The reachable workspace is generated with a boundary-searching discretization approach, and the local and global performance atlas, including stiffness and dexterity, are investigated. The multi-population evolution of structural and behavioral parameters is implemented to seek the optimal dexterity of the hybrid head mechanism.     

An algorithm and observability research of autonomous navigation and joint attitude determination in asteroid exploration descent stage

In this paper, an autonomous relative navigation and joint attitude determination algorithm in asteroid exploration descent stage is researched based on feature point information of perpendicular asteroid surface image observed by optical navigation camera, distance vectors from spacecraft to asteroid measured by three angled installed lidars and relative velocity increment measured by accelerometer when the relative distance vector to the centroid of asteroid can not be obtained. The inertial attitude of spacecraft is determined by sun vector, star vectors and inertial angular velocity respectively measured by sun sensor, star trackers and inertial reference unit. Also, in order to obtain measurement error model transferred from sensor noise, a covariance matrix solver considering error correlation is presented via the error model of normalized vector to first order. Numerical simulation and improved observability evaluation of filtering are undertaken to discuss the results of complete sensor observation and weak observation of lidars, and verify the effectiveness of the presented relative navigation and attitude determination algorithm.     

Navigation system for an autonomous robot using an ocellus camera in an indoor environment

Autonomous and mobile robots are being expected to provide various services in human living environments. However, many problems remain to be solved in the development of autonomous robots that can work like humans. When a robot moves, it is important that it be able to have self-localization abilities and recognize obstacles. For a human, the present location can be correctly checked through a comparison between memorized information assuming, it is correct, and the present situation. In addition, the distance to an object and the perception of its size can be estimated by a sense of distance based on memory or experience. Therefore, the environment for robotic activity assumed in this study was a finite-space such as a family room, an office, or a hospital room. Because an accurate estimation of position is important to the success of a robot, we have developed a navigation system with self-localization ability which uses only a CCD camera that can detect whether the robot is moving accurately in a room or corridor. This article describes how this system has been implemented and tested with our developed robot.     

Development of distance recognition using an ocellus camera for an autonomous personal robot

We are attempting to develop an autonomous personal robot that has the ability to perform practical tasks in a human living environment by using information derived from sensors. When a robot operates in a human environment, the issue of safety must be considered in regard to its autonomous movement. Thus, robots absolutely require systems that can recognize the external world and perform correct driving control. We have thus developed a navigation system for an autonomous robot. The system requires only image data captured by an ocellus CCD camera. In this system, we allow the robot to search for obstacles present on the floor. Then, the robot obtains distance recognition necessary for evasion of the object, including data of the obstacle’s width, height, and depth by calculating the angles of images taken by the CCD camera. We applied the system to a robot in an indoor environment and evaluated its performance, and we consider the resulting problems in the discussion of our experimental results. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Circling turning locomotion of a new multiple closed-chain-legs robot with hybrid-driven mechanism

A multi-legged robot based on a hybrid-driven mechanism is presented in this paper as an improvement of the legged robot based on crank-driven linkage mechanism. A hybrid-driven mechanism containing a full-rotational degree of freedom (DOF) and a linear translational DOF was obtained after a series of foot trajectory analyses on the Jansen mechanism. The stance phase trajectory of this hybrid-driven mechanism can maintain horizontality regardless of the length adjustment of the linear DOF. A turning gait of a hexapod robot based on this hybrid-driven mechanism was proposed, such that all of the legs had an identical crank angular speed, and the robot turned its orientation through different linear servo controls on the legs of the two sides. Simulation and experimental results showed that the hexapod robot could realize the turning gait when the legs of the two sides applied different length adjustments. The body center trajectories in all cases were approximate to a circle, and the smallest turning radius was close to the length of the robot. Moreover, the magnitude of the pitch and roll angles, and body center fluctuation in the simulations was all small, indicating that the hexapod robot based on the hybrid-driven mechanism was stable during the turning locomotion.     

基于CCD的自主机器人高速运行控制算法设计

基于特定的机械结构和电气特性的单目CCD轮式机器人,提出一种高速控制算法,使机器人发挥最优速度潜能。该算法采用图像定位模型,根据当前机器人的位置信息,模拟可能的转向角下的运行轨迹,参考规则数据库,给出最优偏转角度和速度控制决策。实验研究表明:该算法具有较好的可行性。     

垂直姿态的非正交测量优化与校正

垂直小角度时,采用的非正交姿态测量方法旨在解决传感器输出信号极微弱和解算精度低等问题。描述了非正交坐标系的理论模型,对其进行了优化,确定了最佳偏置角度。利用补偿矩阵对因测斜仪安装问题引入的位置误差进行校正,通过井斜角和工具面角的解算结果验证校正效果。测试结果表明,在偏置角为45°时,姿态参数具有较高的解算精度;而数据校正能大幅度降低位置误差,进一步提高测量精度。     

基于Solis&Wets算法的机器人最优测量构形研究

研究了机器人标定中最优测量构形的选择,采用奇异值分解方法获得了机器人误差传播矩阵的条件数,以该条件数为优化的目标函数,利用Solis&Wets算法来选择机器人的一系列最优测量构形,以最小化参数估计中测量和建模误差的影响。实验结果表明该方法的标定结果优于随机选择的标定构形的标定结果。     

机器人听觉声源定位研究综述

声源定位技术定位出外界声源相对于机器人的方向和位置,机器人听觉声源定位系统可以极大地提高机器人与外界交互的能力.总结和分析面向机器人听觉的声源定位技术对智能机器人技术的发展有着重要的意义.首先总结了面向机器人听觉的声源定位系统的特点,综述了机器人听觉声源定位的关键技术,包括到达时间差、可控波束形成、高分辨率谱估计、双耳听觉、主动听觉和视听融合技术.其次对麦克风阵列模型进行了分类,比较了基于三维麦克风阵列、二维麦克风阵列和双耳的7个典型系统的性能.最后总结了机器人听觉声源定位系统的应用,并分析了存在的问题和未来的发展趋势.     

A simple model for laser drilling

A simple mathematical model of laser drilling is proposed. Assuming axi-symmetry of the process around the axis of the laser beam, a one-dimensional formulation is obtained after cross-sectional averaging. The novelty of the approach relies on the fact that even after dimension reduction, the shape of the hole can still be described. The model is derived, implemented and validated for drilling using lasers with intensities in the GW/cm² range and microsecond pulses.     

浮空器惯性姿态测量系统冗余CAN总线设计

为满足浮空器惯性姿态测量系统在高空长航时环境下对CAN通信高可靠性的要求,设计了一种双CAN总线全系统冗余方案。采用两片集成度较高的LPC11C24微控制器,在DSP+FPGA架构的导航计算机上搭建冗余系统,并结合上位机对该系统进行了测试与验证。测试结果表明,该冗余系统通信功能正常。当主CAN出现故障时,从CAN投入运行,有较好的容错性,在不增加成本和空间的前题下,提高了惯性姿态测量系统的可靠性。     

基于红外传感原理的无人机姿态测量系统设计

由于红外温度传感器能有效感知天空间的热辐射,并且相比传统姿态测量的传感器具有体积小、重量轻、成本低等特点,设计一种基于红外传感原理的无人机姿态测量系统;该系统以新型的ARM Cortex—M3内核微处理器STM32F103ZET6作为处理单元,通过采集红外传感器的姿态信息,进行姿态解算,进而获得无人机的姿态角;同时分析了太阳干扰对实验的影响。实验测试表明:该姿态测量系统简单实用,性能稳定,精度高,能有效满足一般无人机姿态测量的要求。     

A robust control scheme for asymptotic tracking of robot motion

In this paper, a controller structure is developed to provide for asymptotic tracking of robot motion. The design tool is the theory of hyperstability and the analysis has led to a simple and an easy-to-implement robust version of the inverse dynamics. Simulation studies are worked out to demonstrate the controller performance. A comparison with other methods is done to show the merits of the developed scheme vs. other recently developed schemes. The implementation and computational requirements of the control schemes are determined and shown to be within the capabilities of new control hardware.This work was supported by the Kuwait University Research Administration under Grant No. EE063.     

Development of a monocular vision system for robotic drilling

Robotic drilling for aerospace structures demands a high positioning accuracy of the robot, which is usually achieved through error measurement and compensation. In this paper, we report the development of a practical monocular vision system for measurement of the relative error between the drill tool center point （TCP） and the reference hole. First, the principle of relative error measurement with the vision system is explained, followed by a detailed discussion on the hardware components, software components, and system integration. The elliptical contour extraction algorithm is presented for accurate and robust reference hole detection. System calibration is of key importance to the measurement accuracy of a vision system. A new method is proposed for the simultaneous calibration of camera internal parameters and hand-eye relationship with a dedicated calibration board. Extensive measurement experiments have been performed on a robotic drilling system. Experimental results show that the measurement accuracy of the developed vision system is higher than 0.15 mm, which meets the requirement of robotic drilling for aircraft structures.