Improvement of 3P and 6R mechanical robots reliability and quality applying FMEA and QFD approaches

In the past few years, extending usage of robotic systems has increased the importance of robot reliability and quality. To improve the robot reliability and quality by applying standard approaches such as Failure Mode and Effect Analysis (FMEA) and Quality Function Deployment (QFD) during the design of robot is necessary. FMEA is a qualitative method which determines the critical failure modes in robot design. In this method Risk Priority Number is used to sort failures with respect to critical situation. Two examples of mechanical robots are analyzed by using this method and critical failure modes are determined for each robot. Corrective actions are proposed for critical items to modify robots reliability and reduce their risks. Finally by using QFD, quality of these robots is improved according to the customers’ requirements. In this method by making four matrixes, optimum values for all technical parameters are determined and the final product has the desired quality.     

Two fault detection and isolation schemes for robot manipulators using soft computing techniques

With growing technology, fault detection and isolation (FDI) have become one of the interesting and important research areas in modern control and signal processing. Accomplishment of specific missions like waste treatment in nuclear reactors or data collection in space and underwater missions make reliability more important for robotics and this demand forces researchers to adapt available FDI studies on nonlinear systems to robot manipulators, mobile robots and mobile manipulators.In this study, two model-based FDI schemes for robot manipulators using soft computing techniques, as an integrator of Neural Network (NN) and Fuzzy Logic (FL), are proposed. Both schemes use M-ANFIS for robot modelling. The first scheme isolates faults by passing residual signals through a neural network. The second scheme isolates faults by modelling faulty robot models for defined faults and combining these models as a generalized observers scheme (GOS) structure. Performances of these schemes are tested on a simulated two-link planar manipulator and simulation results and a comparison according to some important FDI specifications are presented.     

Design of a modular assembly of four-footed robots with multiple functions

Modern industries use many types of robots. In addition to general robotic arms, bipedal, tripedal, and quadrupedal robots, which were originally developed as toys, are gradually being used for multiple applications in manufacturing processes. This research begins with establishing the platform for four-footed robots with multiple functions, high sensitivity, and modular assembly and this is how a fundamental model of the industrial robots is constructed. Under additional loads, the four feet of the quadrupedal robot reinforce its carrying ability and reliability compared to bipedal or tripedal robots, which helps it to carry more objects and enhances functionality. Based on different requirements and demands from the manufacturing processes, the highly sensitive four-footed robot provides an expandable interface to add different sensing components. In addition, when combined with a wireless communication module or independent 1.2 GHz radio frequency CCD wireless image transmission system, the user can control the robot remotely and instantly. The design helps the four-footed robot to expand its applications. By assembling and disassembling modules and changing the sensing components, the highly sensitive four-footed robot can be used for different tasks. Moreover, the remote control function of the robot will increase interaction with human beings, so it can become highly become involved in people's lives. The platform of the four-footed robot will become a design reference for the commercialization of different industrial robots, and it will provide the design of industrial robots with more options and useful applications.     

Particle Filter for Collaborative Multi-Robot Localization Tolerant to Recognition Error

Statistical algorithms using particle filters have been proposed previously for collaborative multi-robot localization. In these algorithms, by synchronizing each robot's belief or exchanging the particles of the robots, fast and accurate localization is attained. However, there algorithms assume correct recognition of other robots and the effects of recognition error are not considered. If the recognition of other robots is incorrect, a large amount of error in localization can occur. This paper describes this problem. Furthermore, in order to cope with the problem, an algorithm for collaborative multi-robot localization is proposed. In the proposed algorithm, the particles of a robot are exchanged with those of other robots according to measurement results obtained by the sending robot. At the same time, some particles remain in the sending robot. Received particles from other robots are evaluated using measurement results obtained by the receiving robot. The proposed method copes with recognition error by using the remaining particles, and increases the accuracy of estimation by twice evaluating the exchanged particles of the sending and receiving robots. These properties of the proposed method are argued mathematically. Simulation results show that incorrect recognition of other robots does not cause serious problems in the proposed method.     

Fault detection for service mobile robots using model-based method

Detection of faults is a topic of high importance because it increases robot dependability, a requirement for the wide acceptance of service robots in domestic environments. This work takes a model-based approach for detecting and identifying actuator faults on differential-drive mobile robots in an indoor environment. An error-bound is calculated between the estimated and measured robot states which is constantly adapted based on the current state and input signals. A fault is detected when the estimation error is outside this bound. The model parameters are learned by the robot using an adaptive law, after the robot deployment in the target environment. Model uncertainties have an important impact on the fault detection performance, and are dealt with by considering the uncertainty bounds in the bound calculations. This ensures no false alarms occur when the uncertainty remains bounded during normal operation. Furthermore an extension to the method is proposed that addresses the problem of detecting small faults. The method is experimentally validated on a iRobot Roomba autonomous robot.     

基于位置反解算法的并联机器人坐标变换方法

目的为提高工作效率,提升工业机器人的可靠性、稳定性和运动精度,避免机器人出现速度以及加速度的突变,对机器人的位置进行准确的控制。方法 以RBT-6T03P并联机器人为例,应用坐标变化法和位置反解算法对并联机器人机构的位置坐标进行分析并利用MATLAB进行仿真。结果 结果表明：通过位置反解对并联机器人的坐标进行变换求解是方便可行。结论 所述控制方法相对于并联机器人求正解算法更加简单、方便、快捷。     

A collaborative localization tolerant to recognition error by double-check particle exchange

Statistical algorithms using particle filters for collaborative multi-robot localization have been proposed. In these algorithms, by synchronizing every robot’s belief or exchanging particles of the robots with each other, fast and accurate localization is attained. These algorithms assume correct recognition of other robots, and the effects of recognition errors are not discussed. However, if the recognition of other robots is incorrect, a large amount of error in localization can occur. This article describes this problem. Furthermore, an algorithm for collaborative multi-robot localization is proposed in order to cope with this problem. In the proposed algorithm, the particles of a robot are sent to other robots according to measurement results obtained by the sending robot. At the same time, some particles remain in the sending robot. Particles received from other robots are evaluated using measurement results obtained by the receiving robot. The proposed method is tolerant to recognition error by the remaining particles and evaluating the exchanged particles in the sending and receiving robots twice, and if there is no recognition error, the proposed method increases the accuracy of the estimation by these two evaluations. These properties of the proposed method are argued mathematically. Simulation results show that incorrect recognition of other robots does not cause serious problems in the proposed method.     

Control circuits simplification and computer programs design on bipedal robot

This study is expected to provide the best design of bipedal robot, which will help widen the application in the future. A new design system is presented through simplification of the control circuit, and the design of computer programs not only lowers the research barriers of the robots but also decreases the development costs. This design system can be used for various operations of manufacturing processes to make up the shortages of the flexibility for the robots. In recent years, the progress in electronics and the control technology has made the robots useful not only for dangerous and automatic tasks, but also for advanced and friendly people service. Thus, the robots have been used in the factories for automation and towards the general use in regular life. Of all robots, the bipedal robot attracts the most attention for its humanoid outlook, user-friendly design, and artificial intelligence for the human society. Many bipedal robots are developed to satisfy consumers’ needs. The control circuits and the program design are the key issues to make the bipedal robots. In this study, a synchronous robot controller for 31°-axis freedom is developed. The authors also equip a memory in the hardware architecture to store all moving commands of the bipedal robot. In terms of internal programs, the authors develop a human interface that synchronizes the movement of the robot and collects the pace data of the robot. The authors use the statistical method to analyze the data and establish a database of the robot's movement. With the database, one can finally drive the robot to walk and generate the pace design of the bipedal robots.     

基于传感器融合技术的机器人远程控制系统设计

结合数据融合技术与无线传输技术,提出了一种基于传感器融合的机器人远程控制系统设计方法。机器人端采用FMCE毫米波雷达与摄像机进行多传感器融合,机器人端与远程PC端采用局域网进行通信,本地PC端对机器人进行远程控制时功能主要有两个,第一个是根据现场作业环境实时控制机器人移动,第二个是在PC端选择目标对象后让机器人生成行驶路径后自动跟踪目标对象,路径跟踪控制器采用的是线性二次型调节器(LQR),这种基于传感器融合的机器人远程控制系统设计方法,具有高效、智能、可靠、精确等优点,可以应用于各种需要机器人协助完成的任务中,如无人巡检、智能交通等领域。     

机器人图标化编程环境的设计及实现

为解决传统机器人文本编程不易于学习和使用的问题,设计了面向机器人的图标化简便编程环境．重点研究了图标化机器人程序语言的设计及其解释执行技术．通过图标化编程环境在工业机器人上的实现和应用,说明图标化编程技术相对于传统文本式编程技术的易用性和高效性．     

Global Output Tracking Control of Flexible Joint Robots via Factorization of the Manipulator Mass Matrix

This paper investigates the problem of global output feedback tracking control of flexible joint robots. Despite the fact that only link position and actuator position are available from measurements, the proposed controller ensures that the link position globally tracks the desired trajectory while keeping all the remaining signals bounded. The controller development uses a partial state-feedback linearization technique combined with the integrator backstepping control design method whereas a filter and an observer are utilized to remove the requirement of link and actuator velocity measurements. Partial state-feedback linearization of robot dynamics is performed by factoring the manipulator mass matrix into a quadratic form involving an integrable root matrix. The applicability of the proposed general design methodology is illustrated by an example of flexible joint planar robots. Numerical results for a two-link flexible joint planar robot are also provided.      

基于蓝牙的无线通信技术及其在机器人中的应用

基于蓝牙的无线通信系统是模块化机器人闭环控制系统的一个重要组成部分,上位机与机器人之间的通信通过蓝牙模块来实现。本文在介绍了蓝牙技术的基础概念的基础上,提出了基于蓝牙的无线通信解决方案,解决了短距离模块化机器人的无线通信问题,简化了机器人无线通信的设计,增加了通信的可靠性。     

Distributed active fault tolerant control design against actuator faults for multiple mobile robots

This paper investigates the active fault tolerant cooperative control problem for a team of wheeled mobile robots whose actuators are subjected to partial or severe faults during the team mission. The cooperative robots network only requires the interaction between local neighbors over the undirected graph and does not assume the existence of leaders in the network. We assume that the communication exists all the time during the mission. To avoid the system''s deterioration in the event of a fault, a set of extended Kalman filters (EKFs) are employed to monitor the actuators'' behavior for each robot. Then, based on the online information given by the EKFs, a reconfigurable sliding mode control is proposed to take an appropriate action to accommodate that fault. In this research study, two types of faults are considered. The first type is a partial actuator fault in which the faulty actuator responds to a partial of its control input, but still has the capability to continue the mission when the control law is reconfigured. In addition, the controllers of the remaining healthy robots are reconfigured simultaneously to move within the same capability of the faulty one. The second type is a severe actuator fault in which the faulty actuator is subjected to a large loss of its control input, and that lead the exclusion of that faulty robot from the team formation. Consequently, the remaining healthy robots update their reference trajectories and form a new formation shape to achieve the rest of the team mission.     

Visual Mark for Robot Manipulation and Its RT-Middleware Component

In this paper, a visual marker called Coded Landmark for Ubiquitous Environment (CLUE) is proposed for easy robot manipulation using the RT-middleware component technology. Currently, home service robots are being expected to work in human living environments; however, such environments might be highly complex for robots. One of the solutions to solve such problems might be the development of structured environments for robots, such as visual marks in human living space, which could often be used in industrial fields, e.g., marked lines for mobile robots in industry. For application of structured environments from the factory to the human living environment, the affinity to humans might be important, such as marks invisible to humans, but visible to robots. In this paper, an invisible marker, CLUE, which is based on QR codes, is proposed; this will provide robots with information on the objects that are to be manipulated and visual guidance required for robot manipulation based on the RT-middleware platform. Finally, by means of actual robot applications, the method to use the proposed robot technology component is shown.     

Concurrent localization of multiple robots

A concurrent localization method for multiple robots using ultrasonic beacons is proposed. This method provides a high-accuracy solution using only low-price sensors. To measure the distance of a mobile robot from a beacon at a known position, the mobile robot alerts one beacon to send out an ultrasonic signal to measure the traveling time from the beacon to the mobile robot. When multiple robots requiring localization are moving in the same block, it is necessary to have a schedule to choose the measuring sequence in order to overcome constant ultrasonic signal interference among robots. However, the increased time delay needed to estimate the positions of multiple robots degrades the localization accuracy. To solve this problem, we propose an efficient localization algorithm for multiple robots, where the robots are in groups of one master robot and several slave robots. In this method, when a master robot calls a beacon, all the group robots simultaneously receive an identical ultrasonic signal to estimate their positions. The effectiveness of the proposed algorithm has been verified through experiments.     

Minimal design for human–agent communication

Robots have been envisaged as both workers and partners of humans from the earliest period in their history. Therefore, robots should become artificial entities that can socially interact with human beings in social communities. Recent advances in technology have added various functions to robots. The development of actuators and grippers show us infinite possibilities for factory automation, and robots can now walk and perform very smoothly. All of these functions have been developed as solutions for improving robot movement and performance. However, there are many remaining problems in the communication between robots and humans. Communication robots provide one approach to the realization of embodied interfaces. Furthermore, the unsolved problems of human–robot communication can be clarified by adopting the concept of subtractive methods. In this article, we consider the minimal design of robots from the viewpoint of designing communication. By minimal design, we mean eliminating the nonessential portions and keeping only the most fundamental functions. We expect that the simple and clean nature of minimally designed objects will allow humans to interact with these robots without becoming uninterested too quickly. By exploiting the fact that humans have “a natural dislike for the absence of reasoning,” artificial entities built according to minimal design principles can extract the human drive to relate with others. We propose a method of designing a robot that has “character” and is situated in a social context from the viewpoint of minimal design. This work was presented in part at the 10th International Symposium on Artificial Life and Robotics, Oita, Japan, February 4–6, 2005     

A modular design of Bayesian networks using expert knowledge: Context-aware home service robot

Recently, demand for service robots increases, and, particularly, one for personal service robots, which requires robot intelligence, will be expected to increase more. Accordingly, studies on intelligent robots are spreading all over the world. In this situation, we attempt to realize context-awareness for home robot while previous robot research focused on image processing, control and low-level context recognition. This paper uses probabilistic modeling for service robots to provide users with high-level context-aware services required in home environment, and proposes a systematic modeling approach for modeling a number of Bayesian networks. The proposed approach supplements uncertain sensor input using Bayesian network modeling and enhances the efficiency in modeling and reasoning processes using modular design based on domain knowledge. We verify the proposed method is useful as measuring the performance of context-aware module and conducting subjective test.     

Design of an shape memory alloy-actuated biomimetic mobile robot with the jumping gait

This paper reports the design, simulation, analysis, and experiments of mesoscale fourlegged robots that can locomote by a jumping gait using only shape memory alloy (SMA) wires as actuators. Through studies of the structure and function of leg muscle groups in vertebrates’ lower musculoskeletal system, three types of muscles are selected for robot leg design, and each muscle is then replaced by an SMA wire in the robot model. Two types of robot models are proposed and analyzed using three sets of computer simulation. It can be concluded from the simulation that the sequence of SMA muscle activation, activation arrangement of the rear and the front legs, and the foot length are primary factors determining the jumping performance. It is observed that when the robot has three degrees of freedom for each leg and a foot length of 40 mm, the maximum jumping height is approximately 120% of the robot’s height and the maximum distance per jump is about 35% of its length. In addition, two robot prototypes are presented based on the design models and experimental results. The simulation and experimental results are found to show good agreement. The overall results show that the proposed robot design and SMA actuation method are feasible for all SMA-driven jumping robots.     

Development of a leg part of a humanoid robot-design of a biped walking robot having antagonistic driven joints using a nonlinear spring mechanism

The authors are engaged in studies of biped walking robots from the following two viewpoints. One is a viewpoint as a human science. The other is a viewpoint towards the development of humanoid robots. In the current research concerning a biped walking robot, there is no developed example of a life-size biped walking robot with antagonistically driven joints by which the human musculo-skeletal system is imitated in the lower limbs. Humans are considered to exhibit walking behavior which is both efficient and capable of flexibly coping with contact with the outside environment. However, developed biped walking robots cannot realize human walking. The human joint is driven by two or more antagonistic muscle groups. Humans can vary the joint stiffness, using nonlinear spring characteristics possessed by the muscles themselves. The function is an indispensable function for a humanoid. Therefore, the authors designed and built an anthropomorphic biped walking robot having antagonistic driven joints. In this paper, the authors introduce the design method of the robot. The authors performed walking experiments with the robot. As a result, a quasi-dynamic biped walking using antagonist driven joint was realized. The walking speed was 7.68 s per step with a 0.1 m step length.     

Socializing robots: constructing robotic sociality in the design and use of the assistive robot PARO

The goal of introducing robots into everyday use has led to their reconceptualization as social technologies, for which interacting with people is a fundamental and necessary function. Robot sociality in this context is generally defined as a set of individual properties of the artifact, such as a human-like appearance or the ability to read social cues. In this paper, we propose an alternative view of robot sociality as an emergent relational property of the interactions between the robot and its social context, actively constructed by designers, users, and other actors affected by robots. We illustrate this perspective through the example of the robot PARO, a commercial social robot commonly used in eldercare, which we analyzed in a series of observational studies of the social processes of its design in the laboratory and its use in an eldercare facility. Our analysis shows how the robot as a social technology is constructed through the actions and sense making of various actors and the situated dynamics of interaction in particular institutional contexts. We first describe the social factors and rationale that influenced PARO’s design in the laboratory, and then discuss how the robot is scaffolded by users in a nursing home in the midwestern United States. Our studies go beyond the typical focus on one-on-one interaction between people and robots as the unit of analysis of human–robot interaction, to incorporate the broader social context as a necessary component of the successful design and implementation of social robots in society.