Integrating a flexible anthropomorphic, robot hand into the control, system of a humanoid robot

This article presents the approaches taken to integrate a novel anthropomorphic robot hand into a humanoid robot. The requisites enabling such a robot hand to use everyday objects in an environment built for humans are presented. Starting from a design that resembles the human hand regarding size and movability of the mechatronical system, a low-level control system is shown providing reliable and stable controllers for single joint angles and torques, entire fingers and several coordinated fingers. Further on, the high-level control system connecting the low-level control system with the rest of the humanoid robot is presented. It provides grasp skills to the superior robot control system, coordinates movements of hand and arm and determines grasp patterns, depending on the object to grasp and the task to execute. Finally some preliminary results of the system, which is currently tested in simulations, will be presented.     

Quasi optimal sagittal gait of a biped robot with a new structure of knee joint

The design of humanoid robots has been a tricky challenge for several years. Due to the kinematic complexity of human joints, their movements are notoriously difficult to be reproduced by a mechanism. The human knees allow movements including rolling and sliding, and therefore the design of new bio-inspired knees is of utmost importance for the reproduction of anthropomorphic walking in the sagittal plane. In this article, the kinematic characteristics of knees were analyzed and a mechanical solution for reproducing them is proposed. The geometrical, kinematic and dynamic models are built together with an impact model for a biped robot with the new knee kinematic. The walking gait is studied as a problem of parametric optimization under constraints. The trajectories of walking are approximated by mathematical functions for a gait composed of single support phases with impacts. Energy criteria allow comparing the robot provided with the new rolling knee mechanism and a robot equipped with revolute knee joints. The results of the optimizations show that the rolling knee brings a decrease of the sthenic criterion. The comparisons of torques are also observed to show the difference of energy distribution between the actuators. For the same actuator selection, these results prove that the robot with rolling knees can walk longer than the robot with revolute joint knees.     

Design of the ATRON lattice-based self-reconfigurable robot

Self-reconfigurable robots are robots that can change their shape in order to better suit their given task in their immediate environment. Related work on around fifteen such robots is presented, compared and discussed. Based on this survey, design considerations leading to a novel design for a self-reconfigurable robot, called “ATRON”, is described. The ATRON robot is a lattice-based self-reconfigurable robot with modules composed of two hemispheres joined by a single revolute joint. Mechanical design and resulting system properties are described and discussed, based on FEM analyses as well as real-world experiments. It is concluded that the ATRON design is both competent and novel. Even though the ATRON modules are minimalistic, in the sense that they have only one actuated degree of freedom, the collective of modules is capable of self-reconfiguring in three dimensions. Also, a question is raised on how to compare and evaluate designs for self-reconfigurable robots, with a focus on lattice-based systems.     

仿人机器人复杂动态动作设计及相似性研究

提出了一种基于人体运动的考虑节奏相似性的仿人机器人复杂动态动作设计方法. 首先, 把人体的运动分割成基本动作段, 给出了运动学约束, 讨论了复杂动态动作的稳定性调节方法. 然后, 提出了考虑运动节奏的仿人机器人模仿人体动作的相似性函数, 并给出了满足运动学约束和动力学稳定性、具有高相似性的运动轨迹求解方法. 最后, 通过在仿人机器人 BHR-2 上进行中国功夫``刀术'实验验证了该方法的有效性.     

A walking pattern generation method of humanoid robot MAHRU-R

This paper proposes an omni-directional walking pattern generation method for a humanoid robot MAHRU-R. To walk stably without falling down, a humanoid robot needs the walking pattern. Our previous walking pattern method generated the walking pattern with linear polynomials of the zero moment point (ZMP). It implemented the simple walking like forward/backward walking, side step walking and turning. However, this method was not sufficient to satisfy the various walking which is combined by forward/backward walking, side step walking and turning. We needed to upgrade the walking pattern generation method to implement an omni-directional walking. We use the linear inverted pendulum model consisted of ZMP and center of mass in order to simplify the computation of walking pattern. The proposed method assumes that the state of the following stride is same to the state of the current stride. Using this assumption of walking pattern, the proposed method generates the stable walking pattern for various walking. And the proposed scheme generates the ZMP trajectory with the quartic polynomials in order to reduce the fluctuation of ZMP trajectory by various walking. To implement the efficient walking pattern, this method proposes three walking modules: periodic step module, transient step module and steady step module. Each step module utilizes weighted least square method with future ZMP position information. The effectiveness of the proposed method is verified by simulations of various walking. And the proposed method is confirmed by the experiment of real humanoid robot MAHRU-R.     

拟人机器人抗干扰行走稳定性分析

通过引入虚拟零力矩点假设,提出了一个多种外界干扰下拟人机器人的整体分析模型,分析了拟人机器人抗干扰行走的稳定性.给出了支撑多边形的计算机表达方法和失稳时旋转边界的确定方法.为了在不同的情况下保持平衡,提出了改变支撑多边形、手的支撑、改变上体重心等3种新的稳定性恢复方法.通过优化从虚拟零力矩点到旋转边界的距离,提出了恢复平衡的优化算法.通过仿真实例验证了所提出方法的正确可行性.     

Concurrent design of a three-link manipulator prototype

This paper presents an affordable and comprehensive robotic model of critical aid to any engineering school involved in teaching robotics. We present the stages of designing a three-link robot manipulator prototype that was built as part of a research project for establishing a prototyping environment for robot manipulators. Building this robot helped to determine the required subsystems and interfaces for building the prototyping environment, and provided hands-on experience for real problems and difficulties that are addressed and solved using this environment. The robot is now successfully used as an educational tool in robotics and control classes.     

Parallel computation of the inertia matrix of a tree type robot using one directional recursion of Newton-Euler formulation

This paper is devoted to the computation of the inertia matrix of a tree structured multi-arm robot system. Based on the PPO-Recursion proposed by the authors for the inertial, coupling, and gravitational dynamics of a robot [9], a parallel algorithm for computing the inertia matrix of chain structure robot has been achieved [10]. In the paper the PPO-Recursion is extended to be applied for the tree structured robot after. Appropriate interpretation of the dynamic properties of the branching link in the tree structure is introduced. The proposed algorithm offers high parallelism and is being under the realization in a transputer network.     

Towards a human–robot symbiotic system

Partnership between a person and a robot could be simplified if the robot were intelligent enough to understand human intentions and perform accordingly. During the last decade, we have been developing such an intelligent robot called ISAC. Originally, ISAC was designed to assist the physically disabled, but gradually became a test bed for more robust human–robot teaming (see http://eecs.vanderbilt.edu/CIS/). In this paper, we will describe a framework for human–robot interaction, a multi-agent based robot control architecture, and short- and long-term memory structures for the robot brain. Two applications will illustrate how ISAC interacts with the human.     

Designing an API at an appropriate abstraction level for programming social robot applications

Whilst robots are increasingly being deployed as social agents, it is still difficult to program them to interact socially. To create usable tools for programming these robots, tool developers need to know what abstraction levels are appropriate for programming social robot applications. We explore this through the iterative design and evaluation of an API for programming social robots. The results show that high level primitives, with a close mapping to social interaction, are suitable for programming social robot applications. However, the abstraction level should not be so high that it takes away too much control from programmers. This has the potential to enable programmers to produce high quality social robot applications with less programming effort.     

Can a humanoid robot continue to draw attention in an office environment?

This study focuses on the use of humanoid robots in office environments, and investigates whether a robot can maintain the attention of passersby after initiation of face-to-face contact. Drawing attention can be considered as a first step in improving the continuity of use of robots; such continuity is one factor in validating their social acceptance, which must be considered when disseminating robots in offices. In this study, we assume that the robot approaches and greets users in order to make the users aware of its presence and encourage them to use it. In particular, the robots used in this study convey various greetings along with three nonverbal indicators (no motion, random motion, and face-to-face contact) when a passerby at the office is close to the robot. For a one-week period, we validated the social acceptance of the robot by examining how these robot motions influenced the rate and continuity of a passerby's attention. The results revealed that face-to-face contact can draw a high degree of attention, and that the presence of the robot affects the continuity with which attention is drawn. Finally, the paper discusses implications for future robot design, in terms of drawing and maintaining high rates of attention from users.     

Evaluation of active wearable assistive devices with human posture reproduction using a humanoid robot*

This study proposes a quantitative evaluation method for assessing active wearable assistive devices that can efficiently support the human body. We utilize a humanoid robot to simulate human users wearing assistive devices owing to various advantages offered by the robot such as quantitative torque measurement from sensors and highly repeatable motion. In this study, we propose a scheme for estimating the supportive torques supplied by a device called stationary torque replacement. To validate the reliability of this evaluation method by using a humanoid robot, we conducted measurements of human muscular activity during assisted motion. Analysis of the measured muscle activity revealed that a humanoid robot closely simulates the actual usage of assistive devices. Finally, we showed the feasibility of the proposed evaluation method through an experiment with the humanoid robot platform HRP-4 and the Muscle Suit active assistive device. With the proposed method, the supportive effects of the assistive device could be measured quantitatively in terms of the static supportive torque acting directly on the body of a simulated human user.     

Design and performance of an intelligent predictive controller for a six-degree-of-freedom robot using the Elman network

The aim of this paper was to propose a recurrent neural network-based predictive controller for robotic manipulators. A neural network controller for a six-joint Stanford robotic manipulator was designed using the generalized predictive control (GPC) and the Elman network. The GPC algorithm, which is a class of digital control method, requires long computational time. This is a disadvantage in real-time robot control; therefore, the Elman network controller was designed to reduce processing time by avoiding the highly mathematical and computational complexity of the GPC. The main reason for choosing the Elman network, amongst several neural network algorithms, was that the presence of feedback loops have a profound impact on the learning capability of the network. The designed neural network controller was able to recover quickly because of its significant generalization capability, which allowed it to adapt very rapidly to changes in inputs. The performance of the controller was also shown graphically using simulation software, including the dynamics and kinematics of the robot model.     

MAHRU-M: A mobile humanoid robot platform based on a dual-network control system and coordinated task execution

This paper introduces a mobile humanoid robot platform able to execute various services for humans in their everyday environments. For service in more intelligent and varied environments, the control system of a robot must operate efficiently to ensure a coordinated robot system. We enhanced the efficiency of the control system by developing a dual-network control system. The network system consists of two communication protocols: high-speed IEEE 1394, and a highly stable Controller Area Network (CAN). A service framework is also introduced for the coordinated task execution by a humanoid robot. To execute given tasks, various sub-systems of the robot were coordinated effectively by this system. Performance assessments of the presented framework and the proposed control system are experimentally conducted. MAHRU-M, as a platform for a mobile humanoid robot, recognizes the designated object. The object’s pose is calculated by performing model-based object tracking using a particle filter with back projection-based sampling. A unique approach is used to solve the human-like arm inverse kinematics, allowing the control system to generate smooth trajectories for each joint of the humanoid robot. A mean-shift algorithm using bilateral filtering is also used for real-time and robust object tracking. The results of the experiment show that a robot can execute its services efficiently in human workspaces such as an office or a home.     

Fuzzy control-based real-time robust balance for a humanoid robot

This paper studies and implements a real-time robust balance control for a humanoid robot under three environment disturbances which are an external thrust, an inclinable platform, and a see-saw. More precisely to say, the robot with robust control can resist an external thrust, stand on a two-axis inclinable platform, or walk on a see-saw successfully. The main feature of the robot is that it has a waist joint which has three degrees of freedom. With the aids of the proposed fuzzy controllers, the robot can change the posture of the body nimbly by adjusting the waist joint and two ankle joints to strengthen the stabilization capacity. The sensory system of the robot includes eight force sensors and one inertial measurement unit sensor in order to measure the center of pressure and the slant angle of the robot’s body. According to the measured data from the sensors and by imitating human reflex actions, the proposed fuzzy controllers perform real-time balance control for the robot under three environment disturbances. According to the experiment results, the stability of the robot is increased at least 32.2 and 61.7% under the first two environment disturbances, respectively. In addition, the robot walking on a see-saw has a success rate of about 95%.     

A humanoid robot that pretends to listen to route guidance from a human

This paper reports the findings for a humanoid robot that expresses its listening attitude and understanding to humans by effectively using its body properties in a route guidance situation. A human teaches a route to the robot, and the developed robot behaves similar to a human listener by utilizing both temporal and spatial cooperative behaviors to demonstrate that it is indeed listening to its human counterpart. The robot's software consists of many communicative units and rules for selecting appropriate communicative units. A communicative unit realizes a particular cooperative behavior such as eye-contact and nodding, found through previous research in HRI. The rules for selecting communicative units were retrieved through our preliminary experiments with a WOZ method. An experiment was conducted to verify the effectiveness of the robot, with the results revealing that a robot displaying cooperative behavior received the highest subjective evaluation, which is rather similar to a human listener. A detailed analysis showed that this evaluation was mainly due to body movements as well as utterances. On the other hand, subjects' utterance to the robot was encouraged by the robot's utterances but not by its body movements.     

仿人机器人相似性运动轨迹跟踪控制研究

提出一种基于带观测器的条件状态反馈控制的仿人机器人相似性运动轨迹跟踪控制方法.首先,分析了7连杆双足机器人动力学模型,阐述了其运动能量方程与动力学特征方程; 其次,基于带观测器的状态反馈控制器原理,构建起三维倒立摆平衡控制模型; 最后,由线性二次型调节器确定状态反馈增益矩阵,使机器人轨迹跟踪误差最小化,以复现出较高相似度的双足步行运动效果.实验验证了该方法的有效性.     

Whole-Body Balance Control of a Humanoid Robot in Real Time Based on ZMP Stability Regions Approach

Abstract

One of the most important and complex tasks for a humanoid robot is to avoid overturning during a bipedal gait. This work aims at setting the base for designing a general balance controller to be used with any humanoid robot. In addition, it is based on a strong simplification of humanoid model which attempts to be used in real-time applications. In particular, several “stability zones” are defined as function of the criticalness of balance. The results are presented in simulation and experimentally, using the humanoid platforms HOAP-3 and TEO.     

Reusable robot system for display and disposal tasks at convenience stores based on a SysML model and RT Middleware

Service robots are increasingly being expected to replace human labor; however, in practical settings, these robots have not been fully utilized, partly because the applications that service robots are expected are quite broad. Suitable hardware and software should be developed in order to cope with a wide variety of applications. Ideally, these resources should be developed using common hardware and software platforms are required. Middleware platforms for robotics software, such as ROS and RT Middleware, have already been developed. However, these platforms still face reusability problems due to the inconsistency present in system architectures. Systems are typically assumed to be reused with a given architecture, and if the user-side software architecture is inconsistent with this assumption, the system's reusability suffers. To address this issue, we propose a procedure for optimizing system development using SysML. In this study, our robot system is designed to complete a display disposal tasks in a convenience store; we verify the validity of the robot system using this task. In addition, to verify the reusability of the developed robot system, we employ system functions developed for another task and demonstrate their reuse and operation.     

A new artificial life body: biologically inspired dynamic bipedal humanoid robots

Recently, a biologically inspired, bipedal, dynamic, humanoid robot was developed at the Artificial Life and Robotics Laboratory of Oita University. This bipedal humanoid robot is able to walk dynamically and to go up and down stairs. The central pattern generator developed produces various types of walking pattern. This robot has a pair of small CMOS color CCD cameras, a speaker, and a microphone in the head part, and will have a GPS, a portable telephone, and other sensors in the body part, so that the integration of locomotion and behavior to achieve specific demonstrations will be realized. This project develops dynamic mobility and the ability for autonomous recognition and navigation using the biological central nervous system, the brain system, and the real-time control system. Also, the design principles that demonstrate the dynamic interaction between neural and mechanical controls will be clarified. In Phase I, the platform of a small, bipedal, humanoid robot is used to develop autonomous locomotion and autonomous sensing and navigation. In Phase II of the project, an iteration on the platform design for human-size, bipedal, humanoid robots will be performed for operational testing. The development of bipedal humanoid robots that capture biological systems with unique principles and practices could dramatically increase their performance in tasks for national security needs.This work was presented in part at the 8th International Symposium on Artificial Life and Robotics, Oita, Japan, January 24–26, 2003